Vered Horwitz - Academia.edu (original) (raw)

Papers by Vered Horwitz

Research paper thumbnail of A comprehensive analysis of corneal mRNA levels during sulfur mustard induced ocular late pathology in the rabbit model using RNA sequencing

Experimental Eye Research, 2019

Exposure to sulfur mustard (SM) may result in severe ocular injuries. While some of the eyes show... more Exposure to sulfur mustard (SM) may result in severe ocular injuries. While some of the eyes show a clinical resolution of the injury (defined as clinically non-impaired), part of the eyes develop irreversible late ocular pathologies (defined as clinically impaired) that may lead to corneal blindness. Understanding the pathological mechanisms underlying the development of the late pathology may lead to improved treatment options. Therefore, this study aimed to investigate the mRNA expression profiles of corneas from clinically impaired, clinically non-impaired and naïve eyes. Rabbit eyes were exposed to SM vapor and a clinical follow-up was carried out up to 4 weeks using a slit lamp microscope. At this time point, corneal tissues from clinically impaired, clinically non-impaired and naïve eyes were processed for RNA sequencing (RNA-seq) and differential expression analyses. The differential expression profiles were further subjected to pathway enrichment analysis using Ingenuity Pathway Analysis (IPA). Real-time PCR was used for RNA-seq validation. The late pathology developed in 54%-80% of the eyes following ocular exposure to SM, clinically manifested by inflammation, corneal opacity and neovascularization. RNA-seq results showed significant differences in mRNA levels of hundreds of genes between clinically impaired, clinically non-impaired and naïve corneas. Pathway enrichment analysis showed common pathways that were activated in all of the exposed eyes, such as Th1 and Th2 activation pathway, in addition to pathways that were activated only in the clinically impaired eyes compared to the clinically non-impaired eyes, such as IL-6 and ERK5 signaling. Corneal mRNA expression profiles for the clinically impaired, clinically nonimpaired and naïve eyes generated a comprehensive database that revealed new factors and pathways, which for the first time were shown to be involved in SM-induced late pathology. Our data may contribute to the research on both the pathological mechanisms that are involved in the development of the late pathology and the protective pathways that are activated in the clinically non-impaired eyes and may point out towards novel therapeutic strategies for this severe ocular injury.

Research paper thumbnail of Novel Therapeutic Strategies for Sulfur Mustard-Induced Ocular Injury Using the Rabbit Model

Research paper thumbnail of Variation in gene expression patterns in effusions and primary tumors from serous ovarian cancer patients

Molecular …, 2005

We observed multidimensional variation in expression patterns among the cancers. Coordinate varia... more We observed multidimensional variation in expression patterns among the cancers. Coordinate variation in expression of genes from two chromosomal regions, 8q and 19q, was seen in subsets of the cancers indicating possible amplifications in these regions. A set of 112 unique ...

Research paper thumbnail of Expression of the 67 kDa laminin receptor and the alpha6 integrin subunit in serous ovarian carcinoma

Clinical and Experimental Metastasis

The aim of this study was to analyze the expression of two laminin receptors, the 67 kDa laminin ... more The aim of this study was to analyze the expression of two laminin receptors, the 67 kDa laminin receptor (LBP) precursor and the alpha6 integrin subunit, in effusions and solid tumors of patients diagnosed with serous ovarian carcinoma and to evaluate their predictive role. Eighty-eight effusions and one hundred sixteen primary (= forty-one) and metastatic (= seventy-five) ovarian carcinomas were evaluated for expression of the above-mentioned mRNAs using in situ hybridization (ISH). LBP protein expression was studied in 24 effusions and 43 solid tumors using immunohistochemistry (IHC). Alpha6 integrin subunit protein expression was studied in 27 effusions using flow cytometry (FCM). Expression of LBP mRNA was frequently detected in both carcinoma (92 of 116 cases, 79%) and stromal (79 of 116 cases, 68%) cells in solid tumors. Expression was still higher in cancer cells in effusions (85 of 88 specimens, 96%). In contrast, alpha6 integrin subunit was less frequently detected in both...

Research paper thumbnail of Re: The Beneficial Effects of Doxycycline, an Inhibitor of Matrix Metalloproteinases, on Sulfur Mustard-induced Ocular Pathologies Depend on the Injury Stage

Current Eye Research, 2014

Research paper thumbnail of Characterization of acute and long-term pathologies of superficial and deep dermal sulfur mustard skin lesions in the hairless guinea pig model

Wound Repair and Regeneration, 2012

Sulfur mustard induces severe acute and prolonged damage to the skin and only partially effective... more Sulfur mustard induces severe acute and prolonged damage to the skin and only partially effective treatments are available. We have previously validated the use of hairless guinea pigs as an experimental model for skin lesions. The present study aimed to characterize a model of a deep dermal lesion and to compare it with the previously described superficial lesion. Clinical evaluation of the lesions was conducted using reflectance colorimetry, trans-epidermal water loss and wound area measurements. Prostaglandin E(2) content, matrix metalloproteinase-2 and 9 activity, and histopathology were conducted up to 4 weeks post-exposure. Sulfur mustard skin injury, including erythema and edema, impairment of skin barrier and wounds developed in a dose-dependent manner. Prostaglandin E(2) content and matrix metalloproteinase-2 and 9 activities were elevated during the wound development and the healing process. Histological evaluation revealed severe damage to the epidermis and deep dermis and vesications. At 4 weeks postexposure, healing was not completed: significantly impaired stratum corneum, absence of hair follicles, and epidermal hyperplasia were observed. These results confirm the use of the superficial and deep dermal skin injuries in the hairless guinea pigs as suitable models that can be utilized for the investigation of the pathological processes of acute as well as long-term injuries. These models will be further used to develop treatments to improve the healing process and prevent skin damage and long-term effects.

Research paper thumbnail of Ocular injuries following sulfur mustard exposure—Pathological mechanism and potential therapy

Toxicology, 2009

Sulfur mustard (SM) is a potent vesicant, known for its ability to cause incapacitation and prolo... more Sulfur mustard (SM) is a potent vesicant, known for its ability to cause incapacitation and prolonged injuries to the eyes, skin and respiratory system. The toxic ocular events following sulfur mustard exposure are characterized by several stages: photophobia starting a few hours after exposure, an acute injury phase characterized by inflammation of the anterior segment and corneal erosions and a delayed phase appearing following a clinically silent period (years in human). The late injury appeared in part of the exposed eyes, expressed by epithelial defects and corneal neovascularization (NV), that lead to vision deficits and even blindness. During the last years we have characterized the temporal development of ocular lesions following SM vapor exposure in rabbits and have shown the existence of two sub-populations of corneas, those exhibiting delayed ocular lesions (clinically impaired) and those exhibiting only minor injuries if at all (clinically non-impaired). The aim of the present study was to investigate the pathological mechanism underlying the delayed injury by focusing on the unique characteristics of each sub-population and to test the efficacy of potential treatments. Clinically impaired corneas were characterized by chronic inflammation, increased matrix metalloproteinase (MMP) activity, poor innervation and limbal damage. Moreover, using impression cytology and histology, we identified the delayed lesions as typical for an ocular surface disorder under the category of limbal epithelial stem cell deficiency (LSCD). These results point to therapeutic directions, using anti-inflammatory drugs, MMPs inhibitors, neurotrophic factors and amniotic membrane transplantation. Topical anti-inflammatory drugs, either steroid (Dexamycin, DEX) or non-steroidal anti-infllammatory drug (NSAID, Voltaren Ophtha) were found to be beneficial in ameliorating the initial inflammatory response and in postponing the development of corneal NV, when given during the first week after exposure. When DEX was administered as a symptomatic treatment against NV, a significant regression in the angiogenic process was observed, however, the effect was temporal and blood vessels reappeared after therapy ceased. Chronic administration (8 weeks) of the MMP inhibitor Doxycycline was also effective in attenuation of the acute and delayed injury. Preliminary results, using amniotic membrane transplantation revealed some decrease of corneal edema with no effect on corneal NV. It is suggested that the chronic inflammation and prolonged impairment of corneal innervation are playing a role in the pathogenesis of the delayed LSCD following SM exposure by creating a pathological microenvironment to limbal epithelial stem cells, thus, leading to their slow death and to a second cascade of pathological events eventually resulting in severe long-term injuries. As of today, only topical anti-inflammatory drugs reached the criteria of an applicable efficient post-exposure ocular treatment for SM injuries. Further studies are required to investigate the effects of SM on epithelial stem cells and their involvement in the pathogenesis of the long-term injuries.

Research paper thumbnail of Characterization of acute and long-term sulfur mustard-induced skin injuries in hairless guinea-pigs using non-invasive methods

Skin Research and Technology, 2010

Skin exposure to sulfur mustard (HD) results in erythema, edema and severe injury, which take lon... more Skin exposure to sulfur mustard (HD) results in erythema, edema and severe injury, which take long time to heal and might impose a heavy burden on the health system. Despite many years of research, there is no treatment that prevents the development of the cytotoxic effects of HD causing acute and prolonged damage to the skin. Therefore, it is of great importance to develop treatments that will ameliorate the extent of injury and improve as well as shorten the healing process. The aim of the present study was to establish a small animal model for a long-term HD-induced skin injury using the hairless guinea-pig (HGP) and to further test the efficacy of anti-inflammatories in ameliorating the pathology. HGPs were exposed to HD vapor on four sites for various time durations (1, 5, 10, 15 and 30 min). Clinical evaluation was conducted using reflectance colorimetry, transepidermal water loss and wound-area measurements. Biochemical [prostaglandin (PGE) content and metalloproteinase-9 (MMP-9) activity] and histopathological evaluations were conducted up to 2 weeks post-exposure. Typical symptoms of HD skin injury developed including erythema and edema and the extent of injury was closely related to the exposure duration. Histological evaluation revealed severe edema, infiltration of inflammatory cells, damage to basal cells and vesication. By 2 weeks, healing was not completed, impaired basement membrane and epithelial hyperplasia were observed. PGE content and MMP-9 activity increased at 2 h post-exposure; however, while PGE returned to baseline levels within 24 h, MMP-9 remained elevated at least up to 48 h. Furthermore, a short-term, topical, anti-inflammatory post-exposure treatment was effective in reducing the extent of the acute injury. These results indicate that the effects of HD on HGP skin are similar to previously shown effects in the pig model and in humans and therefore support the use of the HGP as an animal model for long-term effects of HD on skin injury and for studying the efficacy of anti-inflammatory treatments.

Research paper thumbnail of The PAC-1 dual specificity phosphatase predicts poor outcome in serous ovarian carcinoma

Gynecologic Oncology, 2004

Data regarding signal transduction pathways in human tumors are largely confined to cell line stu... more Data regarding signal transduction pathways in human tumors are largely confined to cell line studies to date. We have recently reported on the activation and prognostic role of mitogen-activated protein kinases (MAPK) in ovarian carcinoma in effusions. The objective of the present study was to investigate the expression and clinical role of dual-specificity phosphatases (DUSP), inhibitors of MAPK signaling, in ovarian cancer cells at this site. Thirty-nine fresh frozen malignant effusions from patients diagnosed with serous ovarian carcinoma were studied for mRNA expression of the DUSP MKP-1, MKP-4, MKP-5, and PAC-1 using RT-PCR. DUSP expression was analyzed for possible correlation with patient age, disease stage, tumor grade, histological grade, chemotherapy status, and survival. MKP-1 and PAC-1 mRNA were found in 36 and 37 effusions, respectively, with expression levels showing considerable variation. MKP-4 and MKP-5 were uniformly absent. MKP-1 showed no association with clinicopathologic parameters. However, PAC-1 expression was significantly higher in effusions obtained before the institution of treatment with both platinum compounds (P = 0.029) and paclitaxel (P = 0.036). In univariate survival analysis, high level of expression of PAC-1 mRNA predicted significantly worse overall survival compared to low expression (mean = 30 vs. 52 months, median = 25 vs. 46 months) (P = 0.007). Despite the limited size of this cohort, our results present the first evidence supporting a clinical role for PAC-1 in ovarian carcinoma. In view of the improved outcome associated with activation of all three MAPK families, as well as their elevated expression and activation in post-chemotherapy specimens presented in our previous work, they also suggest that PAC-1 is a true negative regulator of MAPK in ovarian carcinoma cells in effusions.

Research paper thumbnail of Mitogen-activated protein kinases (MAPK) as predictors of clinical outcome in serous ovarian carcinoma in effusions

Gynecologic Oncology, 2003

ObjectiveThe objective was to investigate the expression (level) and phosphorylation status (acti... more ObjectiveThe objective was to investigate the expression (level) and phosphorylation status (activity) of the extracellular-regulated kinase (ERK), c-Jun amino-terminal kinase (JNK), and high-osmolarity glycerol response kinase (p38), their role in the biology of ovarian carcinoma, and their correlation with chemotherapy response.

Research paper thumbnail of Beneficial effects of activated macrophages on sulfur mustard-induced cutaneous burns, an in vivo experience

Cutaneous and Ocular Toxicology, 2014

Objective: Macrophages are known to have key functions in almost every stage of wound healing and... more Objective: Macrophages are known to have key functions in almost every stage of wound healing and there is evidence for their beneficial effects in treating decubital ulcers and deep sternal wound infections in human. This study aimed to investigate the efficacy of a treatment with activated macrophages on ameliorating acute and long-term sulfur mustard (SM) induced skin injuries in the hairless guinea pig (HGP) model. Methods: HGP were exposed to SM vapor and treated with either a single or multiple intradermal injections of human activated macrophages in suspension (hAMS) into the wound bed. Clinical and histological evaluations were conducted up to 4 weeks post-exposure. Results: A single treatment with hAMS early after exposure (15 min and 6 h) resulted in a reduction in the number of damaged cells and vesications in the epidermis at 24 h. A substantial increase in cellular infiltration, mostly polymorphonuclears, was taking place in the hAMS-treated animals starting as early as 1 h after exposure. This flow of inflammatory cells continued, in the treated group, for at least 4 weeks, long after the injected macrophages were not detected. Repeated injections of hAMS (15 min, 48 h and 7 d post-exposure) decreased significantly the area of the wounds and improved the integrity of the barrier function as expressed by measuring trans-epidermal water loss up to 10 d.

Research paper thumbnail of Delayed Loss of Corneal Epithelial Stem Cells in a Chemical Injury Model Associated with Limbal Stem Cell Deficiency in Rabbits

Current Eye Research, 2011

Ocular injuries following exposure to the chemical agent sulfur mustard (SM) are characterized by... more Ocular injuries following exposure to the chemical agent sulfur mustard (SM) are characterized by acute corneal erosions and inflammation of the anterior segment that may be followed by delayed Partial Limbal Stem Cell Deficiency (LSCD), expressed clinically by corneal neovascularization and epithelial defects. LSCD may derive from direct destruction of limbal stem cells or indirectly from altered limbal stromal niche. The aim of this study was to investigate the mechanism underlying LSCD in SM injuries, focusing on the effects of the chemical on limbal epithelium. Rabbit eyes were exposed to SM vapor and were observed by slit lamp examinations and pachymetry. Eyes were taken for histological and molecular biology evaluations at different time points (4 h-4 weeks), to include acute and delayed injuries. Epithelial stem cells were identified by ABCG2, p63 and by in vivo BrdU labeling for slow cycling cells. Limbal stem cells were not damaged during the acute phase following SM exposure, in contrast to the severe injury of the central corneal epithelium. On the contrary, limbal epithelium became activated, responding to corneal insult with a wound healing process, as shown by histology and by transient elevation of the stem cells markers. Simultaneously, inflammation was taking place in the limbal stroma lasting for weeks. A gradual loss of stem cells was observed later-on (2-4 weeks), associated with typical symptoms of LSCD. LSCD associated with SM ocular toxicity was not derived from a direct cytotoxic effect on the epithelial stem cells, but apparently from pathological events at the limbal stroma, that produced an abnormal microenvironment for the stem cells, triggering their gradual death. The results, and in particular the absence of a primary damage to the epithelial stem cells, indicate the presence of a therapeutic window for intervention to avoid the development of the delayed LSCD.

Research paper thumbnail of The Beneficial Effects of Doxycycline, An Inhibitor of Matrix Metalloproteinases, on Sulfur Mustard-Induced Ocular Pathologies Depend on the Injury Stage

Current Eye Research, 2014

Sulfur mustard (SM) induces acute ocular lesions, including erosions and inflammation that may be... more Sulfur mustard (SM) induces acute ocular lesions, including erosions and inflammation that may be followed by delayed injuries expressed by epithelial defects and neovascularization (NV). Based on the matrix metalloproteinases (MMPs) activity, we evaluated the clinical and biochemical effects of topical treatment with doxycycline, an MMP inhibitor, targeted to the various injury stages. Rabbit eyes were exposed to SM vapor. A clinical follow-up was carried out up to 2 months. Tear fluid and cornea samples were collected at different time points for measurements of MMPs activity by zymography. Efficacy of a post-exposure topical doxycycline (2 mg/ml in phosphate buffer saline, ×4/d), targeted to the different phases of the clinical injury, was evaluated. Elevated MMP-9 and MMP-2 activities were found in all corneas during the acute injury and in vascularized corneas during the delayed pathology. In the tear fluid, high MMP-9 activity and negligible MMP-2 activity were found in all the exposed eyes until after the appearance of the delayed pathology symptoms. Prolonged doxycycline treatment reduced MMP-9 activity in the tear fluid. During the acute phase, doxycycline treatment reduced corneal MMP-9 activity and the severity of the injury. Targeting the delayed pathology, doxycycline was clinically efficient only when treatment began before NV appearance. This in vivo study showed the involvement of MMP-9 and MMP-2 during different phases of the SM-induced ocular injury, and the potential of doxycycline treatment as a post exposure measure for reducing the acute injury and as a preventive therapy for ameliorating the delayed pathology. The tear fluid provided a non-invasive method for continuous follow-up of MMPs activity and revealed additional beneficial aspects of injury and the treatment.

Research paper thumbnail of Cultivation and Characterization of Limbal Epithelial Stem Cells on Contact Lenses With a Feeder Layer

Cornea, 2014

Limbal epithelial sheets are used to promote corneal surface reconstruction after the detection o... more Limbal epithelial sheets are used to promote corneal surface reconstruction after the detection of limbal epithelial stem cell deficiency. The aim of this study was to evaluate a novel combination of limbal stem cells (LSCs) maintained on contact lenses (CLs) in the presence of a 3T3 feeder cell layer regarding preservation of stem cell phenotype and the potential use for future in vivo transplantation. Limbal epithelial cells were isolated from rabbit cornea and cultured with 3T3 cells on CLs. The preservation of LSC phenotype was determined using p63α and ABCG2 immunostaining, whereas epithelial differentiation was evaluated using CK3 and CK19. The colony-forming assay was used to determine the percentage of LSCs in cultures. Finally, CLs seeded with PKH26-labeled LSCs were transferred to rabbit eyes after performing a surgical keratectomy, and the transition and phenotype of labeled cells on the corneal surface were evaluated in whole-mount corneas. Proliferation of individual limbal cells was observed on CLs with a 3T3 feeder cell layer, showing holoclone formation and retention of viable stem or progenitor cell phenotype. Finally, a higher transition of cultivated cells after a dual sequential CL transplantation to the ocular surface was observed, showing the preservation of the LSC phenotype in the corneal surface. Limbal cells cultivated on a CL carrier overlaying a 3T3 feeder layer are mitotically active and retain the LSC phenotype. This novel technique of using CLs as a carrier offers an easily manipulable and nonimmunogenic method for transferring LSCs for ocular surface reconstruction in patients with limbal epithelial stem cell deficiency.

Research paper thumbnail of Laminin-Induced Signaling in Tumor Cells: The Role of the Mr 67,000 Laminin Receptor

Cancer Research, 2004

The expression of the M r 67,000 laminin receptor, a nonintegrin laminin receptor, was found to b... more The expression of the M r 67,000 laminin receptor, a nonintegrin laminin receptor, was found to be up-regulated in neoplastic cells and to directly correlate with invasion and metastatic potential. In the present study, we investigated the role of laminin receptor in mediating laminin effects and the involvement of the mitogen-activated protein kinases (MAPK) cascades and dual-specificity phosphatases in laminin signaling in human melanoma cells. Using stable transfection of A375SM melanoma cells, we established lines expressing reduced or elevated laminin receptor. The antisense-transfected cells demonstrated reduced attachment to laminin and reduced invasion through Matrigel-coated filters. In addition, both matrix metalloproteinase-2 (MMP-2) mRNA expression and activity were significantly reduced in the antisense-transfected cells. Antisensetransfected cells showed a reduction in mRNA level of the ␣6B integrin subunit isoform, whereas no change in the mRNA level of the ␣6A isoform was observed. We found that exogenous laminin reduced the phosphorylated (active) form of extracellular signal-regulated kinase, c-Jun NH 2terminal protein kinase, and p38 in all of the cells, irrespective of the expression of the laminin receptor. Furthermore, the phosphorylation of extracellular signal-regulated kinase, c-Jun NH 2 -terminal protein kinase, and p38 was significantly higher in the cell lines expressing reduced laminin receptor, regardless of the exposure to exogenous laminin. This increase of MAPK phosphorylation was accompanied by a significant reduction in MKP-1 phosphatase mRNA level and a significant increase in PAC-1 phosphatase mRNA level. In conclusion, our results confirm the involvement of the laminin receptor in different mechanisms related to tumor dissemination and provide first evidence of the involvement of MAPK and dual-specificity phosphatases in its signal transduction pathway.

Research paper thumbnail of Laminin-induced signaling in tumor cells

Cancer Letters, 2005

Laminin is the main non-collagenous glycoprotein found in the basement membrane. The various lami... more Laminin is the main non-collagenous glycoprotein found in the basement membrane. The various laminin isoforms are involved in many physiological and pathological processes, including cancer dissemination. The interaction of cancer cells with laminin was identified as a key event in tumor invasion and metastasis. Laminin effects are mediated by laminin receptors that are divided into two groups: integrin and non-integrin receptors. Activation of a specific signal transduction pathway in the cell depends on various factors and may be altered when normal tissue becomes neoplastic. Laminin signals via multiple signal transduction pathways involving various components such as G-proteins, intracellular calcium, phospholipase D, mitogen activated protein kinases, phosphatases, focal adhesion kinase, small GTPases of the Rho family, and cytoskeleton components. This review focuses on the role of laminin in tumor progression, its signaling via the non-integrin 67kDa laminin receptor and via integrins and the reciprocal relations between these receptors in certain tumors.

Research paper thumbnail of Expression of the 67 kDa laminin receptor and the α6 integrin subunit in serous ovarian carcinoma

Clinical and …, 2003

Vered Givant-Horwitz1, Ben Davidson2, Gregg van de Putte3, Hiep Phuc Dong2, Iris Goldberg4, Sivan... more Vered Givant-Horwitz1, Ben Davidson2, Gregg van de Putte3, Hiep Phuc Dong2, Iris Goldberg4, Sivan Amir1, Gunnar B. Kristensen3 & Reuven Reich1,5 1Department of Pharmacology and Experimental Therapeutics, Faculty of Medicine, Hebrew University, Jerusalem, ...

Research paper thumbnail of Caveolin-1 Expression in Ovarian Carcinoma Is MDR1 Independent

American Journal of Clinical Pathology, 2002

We studied the role of caveolin-1 in tumor progression and prognosis in serous ovarian carcinoma ... more We studied the role of caveolin-1 in tumor progression and prognosis in serous ovarian carcinoma and the association between caveolin-1 and MDR1 expression. The study involved immunohistochemical analysis for caveolin-1 and P-glycoprotein (P-gp) expression in 75 effusions and 90 solid lesions from ovarian and primary peritoneal carcinoma; in situ hybridization for MDR1 messenger RNA (mRNA) expression in 62 effusions and all 90 tumors; and reverse transcription-polymerase chain reaction (RT-PCR) for caveolin-1 mRNA expression in 23 effusions. Immunohistochemical analysis localized caveolin-1 to the cell membrane in 43 effusions and 24 tumors. P-gp membrane expression was detected in 14 effusions and 11 tumors; MDR1 mRNA, in 20 effusions and 30 tumors. Caveolin-1 mRNA was expressed in 19 effusions. Caveolin-1 protein expression showed no association with that of P-gp protein or MDR1 mRNA. The expression of all markers was similar in carcinoma cells in pleural and peritoneal effusions. Caveolin-1 is a novel diagnostic marker for effusions; expression is moderately elevated in tumor cells in effusions, possibly owing to altered signal transduction and metabolism in cancer cells at this site. Expression seems MDR1 independent.

Research paper thumbnail of Expression of Membrane-Type 1, 2, and 3 Matrix Metalloproteinases Messenger RNA in Ovarian Carcinoma Cells in Serous Effusions

American Journal of Clinical Pathology, 2001

We studied the levels of matrix metalloproteinase (MMP)-2, membrane-type (MT)1-MMP, MT2-MMP, and ... more We studied the levels of matrix metalloproteinase (MMP)-2, membrane-type (MT)1-MMP, MT2-MMP, and MT3-MMP in 43 malignant pleural and peritoneal effusions using reverse transcription-polymerase chain reaction (RT-PCR) and cellular localization of MT1-MMP in 66 effusion specimens and 85 corresponding primary and metastatic tumors using messenger RNA (mRNA) in situ hybridization (ISH). In 43 effusions, MMP-2 mRNA was detected in 37, MT1-MMP in 25, and MT2-MMP in 32. Expression of MT1-MMP and MT2-MMP was found in 21 specimens; in 16 MT-MMP-positive specimens, mRNA for only 1 of 2 enzymes was expressed. MT3-MMP mRNA was not detected. High levels of MMP-2 mRNA were detected more often in effusions with high MT1-MMP and/or MT2-MMP mRNA expression. Using ISH, MT1-MMP mRNA was localized to cancer cells in 27 of 58 malignant effusions; focal signals were detected in mesothelial cells in 7 of 42. MT1-MMP was localized to tumor cells in 32 of 85 primary and metastatic solid lesions, and stromal cells expressed MT1-MMP in 3. Tumor cell MT1-MMP expression in effusion specimens did not differ from primary or metastatic lesions. MT-MMP expression in tumor cells in effusions showed no association with effusion site or tumor type using ISH and RT-PCR.

Research paper thumbnail of Matrix metalloproteinases (MMP), EMMPRIN (extracellular matrix metalloproteinase inducer) and mitogen-activated protein kinases (MAPK): co-expression in metastatic serous ovarian carcinoma

Clinical & experimental metastasis, 2003

Activation or suppression of intracellular signaling via the mitogen-activated protein kinase (MA... more Activation or suppression of intracellular signaling via the mitogen-activated protein kinase (MAPK) family has been linked to expression of matrix metalloproteinases (MMP) in experimental models, but this association has not been demonstrated in clinical material. The objective of this study was to investigate the possible association between expression and activity of MMP, expression of the MMP inducer EMMPRIN, and the expression (level) and phosphorylation status (activity) of the extracellular-regulated kinase (ERK), c-Jun amino-terminal kinase (JNK) and high osmolarity glycerol response kinase (p38) in effusions from patients diagnosed with serous ovarian carcinoma. MAPK level and activity were studied in 55 effusions using immunoblotting. MMP-1, MMP-2, MMP-9 and EMMPRIN expression was studied using immunocytochemistry (ICC) and mRNA in situ hybridization (ISH). The gelatinolytic activity of MMP-2 and MMP-9 was measured by zymography. ERK and phospho-ERK (p-ERK) were detected i...

Research paper thumbnail of A comprehensive analysis of corneal mRNA levels during sulfur mustard induced ocular late pathology in the rabbit model using RNA sequencing

Experimental Eye Research, 2019

Exposure to sulfur mustard (SM) may result in severe ocular injuries. While some of the eyes show... more Exposure to sulfur mustard (SM) may result in severe ocular injuries. While some of the eyes show a clinical resolution of the injury (defined as clinically non-impaired), part of the eyes develop irreversible late ocular pathologies (defined as clinically impaired) that may lead to corneal blindness. Understanding the pathological mechanisms underlying the development of the late pathology may lead to improved treatment options. Therefore, this study aimed to investigate the mRNA expression profiles of corneas from clinically impaired, clinically non-impaired and naïve eyes. Rabbit eyes were exposed to SM vapor and a clinical follow-up was carried out up to 4 weeks using a slit lamp microscope. At this time point, corneal tissues from clinically impaired, clinically non-impaired and naïve eyes were processed for RNA sequencing (RNA-seq) and differential expression analyses. The differential expression profiles were further subjected to pathway enrichment analysis using Ingenuity Pathway Analysis (IPA). Real-time PCR was used for RNA-seq validation. The late pathology developed in 54%-80% of the eyes following ocular exposure to SM, clinically manifested by inflammation, corneal opacity and neovascularization. RNA-seq results showed significant differences in mRNA levels of hundreds of genes between clinically impaired, clinically non-impaired and naïve corneas. Pathway enrichment analysis showed common pathways that were activated in all of the exposed eyes, such as Th1 and Th2 activation pathway, in addition to pathways that were activated only in the clinically impaired eyes compared to the clinically non-impaired eyes, such as IL-6 and ERK5 signaling. Corneal mRNA expression profiles for the clinically impaired, clinically nonimpaired and naïve eyes generated a comprehensive database that revealed new factors and pathways, which for the first time were shown to be involved in SM-induced late pathology. Our data may contribute to the research on both the pathological mechanisms that are involved in the development of the late pathology and the protective pathways that are activated in the clinically non-impaired eyes and may point out towards novel therapeutic strategies for this severe ocular injury.

Research paper thumbnail of Novel Therapeutic Strategies for Sulfur Mustard-Induced Ocular Injury Using the Rabbit Model

Research paper thumbnail of Variation in gene expression patterns in effusions and primary tumors from serous ovarian cancer patients

Molecular …, 2005

We observed multidimensional variation in expression patterns among the cancers. Coordinate varia... more We observed multidimensional variation in expression patterns among the cancers. Coordinate variation in expression of genes from two chromosomal regions, 8q and 19q, was seen in subsets of the cancers indicating possible amplifications in these regions. A set of 112 unique ...

Research paper thumbnail of Expression of the 67 kDa laminin receptor and the alpha6 integrin subunit in serous ovarian carcinoma

Clinical and Experimental Metastasis

The aim of this study was to analyze the expression of two laminin receptors, the 67 kDa laminin ... more The aim of this study was to analyze the expression of two laminin receptors, the 67 kDa laminin receptor (LBP) precursor and the alpha6 integrin subunit, in effusions and solid tumors of patients diagnosed with serous ovarian carcinoma and to evaluate their predictive role. Eighty-eight effusions and one hundred sixteen primary (= forty-one) and metastatic (= seventy-five) ovarian carcinomas were evaluated for expression of the above-mentioned mRNAs using in situ hybridization (ISH). LBP protein expression was studied in 24 effusions and 43 solid tumors using immunohistochemistry (IHC). Alpha6 integrin subunit protein expression was studied in 27 effusions using flow cytometry (FCM). Expression of LBP mRNA was frequently detected in both carcinoma (92 of 116 cases, 79%) and stromal (79 of 116 cases, 68%) cells in solid tumors. Expression was still higher in cancer cells in effusions (85 of 88 specimens, 96%). In contrast, alpha6 integrin subunit was less frequently detected in both...

Research paper thumbnail of Re: The Beneficial Effects of Doxycycline, an Inhibitor of Matrix Metalloproteinases, on Sulfur Mustard-induced Ocular Pathologies Depend on the Injury Stage

Current Eye Research, 2014

Research paper thumbnail of Characterization of acute and long-term pathologies of superficial and deep dermal sulfur mustard skin lesions in the hairless guinea pig model

Wound Repair and Regeneration, 2012

Sulfur mustard induces severe acute and prolonged damage to the skin and only partially effective... more Sulfur mustard induces severe acute and prolonged damage to the skin and only partially effective treatments are available. We have previously validated the use of hairless guinea pigs as an experimental model for skin lesions. The present study aimed to characterize a model of a deep dermal lesion and to compare it with the previously described superficial lesion. Clinical evaluation of the lesions was conducted using reflectance colorimetry, trans-epidermal water loss and wound area measurements. Prostaglandin E(2) content, matrix metalloproteinase-2 and 9 activity, and histopathology were conducted up to 4 weeks post-exposure. Sulfur mustard skin injury, including erythema and edema, impairment of skin barrier and wounds developed in a dose-dependent manner. Prostaglandin E(2) content and matrix metalloproteinase-2 and 9 activities were elevated during the wound development and the healing process. Histological evaluation revealed severe damage to the epidermis and deep dermis and vesications. At 4 weeks postexposure, healing was not completed: significantly impaired stratum corneum, absence of hair follicles, and epidermal hyperplasia were observed. These results confirm the use of the superficial and deep dermal skin injuries in the hairless guinea pigs as suitable models that can be utilized for the investigation of the pathological processes of acute as well as long-term injuries. These models will be further used to develop treatments to improve the healing process and prevent skin damage and long-term effects.

Research paper thumbnail of Ocular injuries following sulfur mustard exposure—Pathological mechanism and potential therapy

Toxicology, 2009

Sulfur mustard (SM) is a potent vesicant, known for its ability to cause incapacitation and prolo... more Sulfur mustard (SM) is a potent vesicant, known for its ability to cause incapacitation and prolonged injuries to the eyes, skin and respiratory system. The toxic ocular events following sulfur mustard exposure are characterized by several stages: photophobia starting a few hours after exposure, an acute injury phase characterized by inflammation of the anterior segment and corneal erosions and a delayed phase appearing following a clinically silent period (years in human). The late injury appeared in part of the exposed eyes, expressed by epithelial defects and corneal neovascularization (NV), that lead to vision deficits and even blindness. During the last years we have characterized the temporal development of ocular lesions following SM vapor exposure in rabbits and have shown the existence of two sub-populations of corneas, those exhibiting delayed ocular lesions (clinically impaired) and those exhibiting only minor injuries if at all (clinically non-impaired). The aim of the present study was to investigate the pathological mechanism underlying the delayed injury by focusing on the unique characteristics of each sub-population and to test the efficacy of potential treatments. Clinically impaired corneas were characterized by chronic inflammation, increased matrix metalloproteinase (MMP) activity, poor innervation and limbal damage. Moreover, using impression cytology and histology, we identified the delayed lesions as typical for an ocular surface disorder under the category of limbal epithelial stem cell deficiency (LSCD). These results point to therapeutic directions, using anti-inflammatory drugs, MMPs inhibitors, neurotrophic factors and amniotic membrane transplantation. Topical anti-inflammatory drugs, either steroid (Dexamycin, DEX) or non-steroidal anti-infllammatory drug (NSAID, Voltaren Ophtha) were found to be beneficial in ameliorating the initial inflammatory response and in postponing the development of corneal NV, when given during the first week after exposure. When DEX was administered as a symptomatic treatment against NV, a significant regression in the angiogenic process was observed, however, the effect was temporal and blood vessels reappeared after therapy ceased. Chronic administration (8 weeks) of the MMP inhibitor Doxycycline was also effective in attenuation of the acute and delayed injury. Preliminary results, using amniotic membrane transplantation revealed some decrease of corneal edema with no effect on corneal NV. It is suggested that the chronic inflammation and prolonged impairment of corneal innervation are playing a role in the pathogenesis of the delayed LSCD following SM exposure by creating a pathological microenvironment to limbal epithelial stem cells, thus, leading to their slow death and to a second cascade of pathological events eventually resulting in severe long-term injuries. As of today, only topical anti-inflammatory drugs reached the criteria of an applicable efficient post-exposure ocular treatment for SM injuries. Further studies are required to investigate the effects of SM on epithelial stem cells and their involvement in the pathogenesis of the long-term injuries.

Research paper thumbnail of Characterization of acute and long-term sulfur mustard-induced skin injuries in hairless guinea-pigs using non-invasive methods

Skin Research and Technology, 2010

Skin exposure to sulfur mustard (HD) results in erythema, edema and severe injury, which take lon... more Skin exposure to sulfur mustard (HD) results in erythema, edema and severe injury, which take long time to heal and might impose a heavy burden on the health system. Despite many years of research, there is no treatment that prevents the development of the cytotoxic effects of HD causing acute and prolonged damage to the skin. Therefore, it is of great importance to develop treatments that will ameliorate the extent of injury and improve as well as shorten the healing process. The aim of the present study was to establish a small animal model for a long-term HD-induced skin injury using the hairless guinea-pig (HGP) and to further test the efficacy of anti-inflammatories in ameliorating the pathology. HGPs were exposed to HD vapor on four sites for various time durations (1, 5, 10, 15 and 30 min). Clinical evaluation was conducted using reflectance colorimetry, transepidermal water loss and wound-area measurements. Biochemical [prostaglandin (PGE) content and metalloproteinase-9 (MMP-9) activity] and histopathological evaluations were conducted up to 2 weeks post-exposure. Typical symptoms of HD skin injury developed including erythema and edema and the extent of injury was closely related to the exposure duration. Histological evaluation revealed severe edema, infiltration of inflammatory cells, damage to basal cells and vesication. By 2 weeks, healing was not completed, impaired basement membrane and epithelial hyperplasia were observed. PGE content and MMP-9 activity increased at 2 h post-exposure; however, while PGE returned to baseline levels within 24 h, MMP-9 remained elevated at least up to 48 h. Furthermore, a short-term, topical, anti-inflammatory post-exposure treatment was effective in reducing the extent of the acute injury. These results indicate that the effects of HD on HGP skin are similar to previously shown effects in the pig model and in humans and therefore support the use of the HGP as an animal model for long-term effects of HD on skin injury and for studying the efficacy of anti-inflammatory treatments.

Research paper thumbnail of The PAC-1 dual specificity phosphatase predicts poor outcome in serous ovarian carcinoma

Gynecologic Oncology, 2004

Data regarding signal transduction pathways in human tumors are largely confined to cell line stu... more Data regarding signal transduction pathways in human tumors are largely confined to cell line studies to date. We have recently reported on the activation and prognostic role of mitogen-activated protein kinases (MAPK) in ovarian carcinoma in effusions. The objective of the present study was to investigate the expression and clinical role of dual-specificity phosphatases (DUSP), inhibitors of MAPK signaling, in ovarian cancer cells at this site. Thirty-nine fresh frozen malignant effusions from patients diagnosed with serous ovarian carcinoma were studied for mRNA expression of the DUSP MKP-1, MKP-4, MKP-5, and PAC-1 using RT-PCR. DUSP expression was analyzed for possible correlation with patient age, disease stage, tumor grade, histological grade, chemotherapy status, and survival. MKP-1 and PAC-1 mRNA were found in 36 and 37 effusions, respectively, with expression levels showing considerable variation. MKP-4 and MKP-5 were uniformly absent. MKP-1 showed no association with clinicopathologic parameters. However, PAC-1 expression was significantly higher in effusions obtained before the institution of treatment with both platinum compounds (P = 0.029) and paclitaxel (P = 0.036). In univariate survival analysis, high level of expression of PAC-1 mRNA predicted significantly worse overall survival compared to low expression (mean = 30 vs. 52 months, median = 25 vs. 46 months) (P = 0.007). Despite the limited size of this cohort, our results present the first evidence supporting a clinical role for PAC-1 in ovarian carcinoma. In view of the improved outcome associated with activation of all three MAPK families, as well as their elevated expression and activation in post-chemotherapy specimens presented in our previous work, they also suggest that PAC-1 is a true negative regulator of MAPK in ovarian carcinoma cells in effusions.

Research paper thumbnail of Mitogen-activated protein kinases (MAPK) as predictors of clinical outcome in serous ovarian carcinoma in effusions

Gynecologic Oncology, 2003

ObjectiveThe objective was to investigate the expression (level) and phosphorylation status (acti... more ObjectiveThe objective was to investigate the expression (level) and phosphorylation status (activity) of the extracellular-regulated kinase (ERK), c-Jun amino-terminal kinase (JNK), and high-osmolarity glycerol response kinase (p38), their role in the biology of ovarian carcinoma, and their correlation with chemotherapy response.

Research paper thumbnail of Beneficial effects of activated macrophages on sulfur mustard-induced cutaneous burns, an in vivo experience

Cutaneous and Ocular Toxicology, 2014

Objective: Macrophages are known to have key functions in almost every stage of wound healing and... more Objective: Macrophages are known to have key functions in almost every stage of wound healing and there is evidence for their beneficial effects in treating decubital ulcers and deep sternal wound infections in human. This study aimed to investigate the efficacy of a treatment with activated macrophages on ameliorating acute and long-term sulfur mustard (SM) induced skin injuries in the hairless guinea pig (HGP) model. Methods: HGP were exposed to SM vapor and treated with either a single or multiple intradermal injections of human activated macrophages in suspension (hAMS) into the wound bed. Clinical and histological evaluations were conducted up to 4 weeks post-exposure. Results: A single treatment with hAMS early after exposure (15 min and 6 h) resulted in a reduction in the number of damaged cells and vesications in the epidermis at 24 h. A substantial increase in cellular infiltration, mostly polymorphonuclears, was taking place in the hAMS-treated animals starting as early as 1 h after exposure. This flow of inflammatory cells continued, in the treated group, for at least 4 weeks, long after the injected macrophages were not detected. Repeated injections of hAMS (15 min, 48 h and 7 d post-exposure) decreased significantly the area of the wounds and improved the integrity of the barrier function as expressed by measuring trans-epidermal water loss up to 10 d.

Research paper thumbnail of Delayed Loss of Corneal Epithelial Stem Cells in a Chemical Injury Model Associated with Limbal Stem Cell Deficiency in Rabbits

Current Eye Research, 2011

Ocular injuries following exposure to the chemical agent sulfur mustard (SM) are characterized by... more Ocular injuries following exposure to the chemical agent sulfur mustard (SM) are characterized by acute corneal erosions and inflammation of the anterior segment that may be followed by delayed Partial Limbal Stem Cell Deficiency (LSCD), expressed clinically by corneal neovascularization and epithelial defects. LSCD may derive from direct destruction of limbal stem cells or indirectly from altered limbal stromal niche. The aim of this study was to investigate the mechanism underlying LSCD in SM injuries, focusing on the effects of the chemical on limbal epithelium. Rabbit eyes were exposed to SM vapor and were observed by slit lamp examinations and pachymetry. Eyes were taken for histological and molecular biology evaluations at different time points (4 h-4 weeks), to include acute and delayed injuries. Epithelial stem cells were identified by ABCG2, p63 and by in vivo BrdU labeling for slow cycling cells. Limbal stem cells were not damaged during the acute phase following SM exposure, in contrast to the severe injury of the central corneal epithelium. On the contrary, limbal epithelium became activated, responding to corneal insult with a wound healing process, as shown by histology and by transient elevation of the stem cells markers. Simultaneously, inflammation was taking place in the limbal stroma lasting for weeks. A gradual loss of stem cells was observed later-on (2-4 weeks), associated with typical symptoms of LSCD. LSCD associated with SM ocular toxicity was not derived from a direct cytotoxic effect on the epithelial stem cells, but apparently from pathological events at the limbal stroma, that produced an abnormal microenvironment for the stem cells, triggering their gradual death. The results, and in particular the absence of a primary damage to the epithelial stem cells, indicate the presence of a therapeutic window for intervention to avoid the development of the delayed LSCD.

Research paper thumbnail of The Beneficial Effects of Doxycycline, An Inhibitor of Matrix Metalloproteinases, on Sulfur Mustard-Induced Ocular Pathologies Depend on the Injury Stage

Current Eye Research, 2014

Sulfur mustard (SM) induces acute ocular lesions, including erosions and inflammation that may be... more Sulfur mustard (SM) induces acute ocular lesions, including erosions and inflammation that may be followed by delayed injuries expressed by epithelial defects and neovascularization (NV). Based on the matrix metalloproteinases (MMPs) activity, we evaluated the clinical and biochemical effects of topical treatment with doxycycline, an MMP inhibitor, targeted to the various injury stages. Rabbit eyes were exposed to SM vapor. A clinical follow-up was carried out up to 2 months. Tear fluid and cornea samples were collected at different time points for measurements of MMPs activity by zymography. Efficacy of a post-exposure topical doxycycline (2 mg/ml in phosphate buffer saline, ×4/d), targeted to the different phases of the clinical injury, was evaluated. Elevated MMP-9 and MMP-2 activities were found in all corneas during the acute injury and in vascularized corneas during the delayed pathology. In the tear fluid, high MMP-9 activity and negligible MMP-2 activity were found in all the exposed eyes until after the appearance of the delayed pathology symptoms. Prolonged doxycycline treatment reduced MMP-9 activity in the tear fluid. During the acute phase, doxycycline treatment reduced corneal MMP-9 activity and the severity of the injury. Targeting the delayed pathology, doxycycline was clinically efficient only when treatment began before NV appearance. This in vivo study showed the involvement of MMP-9 and MMP-2 during different phases of the SM-induced ocular injury, and the potential of doxycycline treatment as a post exposure measure for reducing the acute injury and as a preventive therapy for ameliorating the delayed pathology. The tear fluid provided a non-invasive method for continuous follow-up of MMPs activity and revealed additional beneficial aspects of injury and the treatment.

Research paper thumbnail of Cultivation and Characterization of Limbal Epithelial Stem Cells on Contact Lenses With a Feeder Layer

Cornea, 2014

Limbal epithelial sheets are used to promote corneal surface reconstruction after the detection o... more Limbal epithelial sheets are used to promote corneal surface reconstruction after the detection of limbal epithelial stem cell deficiency. The aim of this study was to evaluate a novel combination of limbal stem cells (LSCs) maintained on contact lenses (CLs) in the presence of a 3T3 feeder cell layer regarding preservation of stem cell phenotype and the potential use for future in vivo transplantation. Limbal epithelial cells were isolated from rabbit cornea and cultured with 3T3 cells on CLs. The preservation of LSC phenotype was determined using p63α and ABCG2 immunostaining, whereas epithelial differentiation was evaluated using CK3 and CK19. The colony-forming assay was used to determine the percentage of LSCs in cultures. Finally, CLs seeded with PKH26-labeled LSCs were transferred to rabbit eyes after performing a surgical keratectomy, and the transition and phenotype of labeled cells on the corneal surface were evaluated in whole-mount corneas. Proliferation of individual limbal cells was observed on CLs with a 3T3 feeder cell layer, showing holoclone formation and retention of viable stem or progenitor cell phenotype. Finally, a higher transition of cultivated cells after a dual sequential CL transplantation to the ocular surface was observed, showing the preservation of the LSC phenotype in the corneal surface. Limbal cells cultivated on a CL carrier overlaying a 3T3 feeder layer are mitotically active and retain the LSC phenotype. This novel technique of using CLs as a carrier offers an easily manipulable and nonimmunogenic method for transferring LSCs for ocular surface reconstruction in patients with limbal epithelial stem cell deficiency.

Research paper thumbnail of Laminin-Induced Signaling in Tumor Cells: The Role of the Mr 67,000 Laminin Receptor

Cancer Research, 2004

The expression of the M r 67,000 laminin receptor, a nonintegrin laminin receptor, was found to b... more The expression of the M r 67,000 laminin receptor, a nonintegrin laminin receptor, was found to be up-regulated in neoplastic cells and to directly correlate with invasion and metastatic potential. In the present study, we investigated the role of laminin receptor in mediating laminin effects and the involvement of the mitogen-activated protein kinases (MAPK) cascades and dual-specificity phosphatases in laminin signaling in human melanoma cells. Using stable transfection of A375SM melanoma cells, we established lines expressing reduced or elevated laminin receptor. The antisense-transfected cells demonstrated reduced attachment to laminin and reduced invasion through Matrigel-coated filters. In addition, both matrix metalloproteinase-2 (MMP-2) mRNA expression and activity were significantly reduced in the antisense-transfected cells. Antisensetransfected cells showed a reduction in mRNA level of the ␣6B integrin subunit isoform, whereas no change in the mRNA level of the ␣6A isoform was observed. We found that exogenous laminin reduced the phosphorylated (active) form of extracellular signal-regulated kinase, c-Jun NH 2terminal protein kinase, and p38 in all of the cells, irrespective of the expression of the laminin receptor. Furthermore, the phosphorylation of extracellular signal-regulated kinase, c-Jun NH 2 -terminal protein kinase, and p38 was significantly higher in the cell lines expressing reduced laminin receptor, regardless of the exposure to exogenous laminin. This increase of MAPK phosphorylation was accompanied by a significant reduction in MKP-1 phosphatase mRNA level and a significant increase in PAC-1 phosphatase mRNA level. In conclusion, our results confirm the involvement of the laminin receptor in different mechanisms related to tumor dissemination and provide first evidence of the involvement of MAPK and dual-specificity phosphatases in its signal transduction pathway.

Research paper thumbnail of Laminin-induced signaling in tumor cells

Cancer Letters, 2005

Laminin is the main non-collagenous glycoprotein found in the basement membrane. The various lami... more Laminin is the main non-collagenous glycoprotein found in the basement membrane. The various laminin isoforms are involved in many physiological and pathological processes, including cancer dissemination. The interaction of cancer cells with laminin was identified as a key event in tumor invasion and metastasis. Laminin effects are mediated by laminin receptors that are divided into two groups: integrin and non-integrin receptors. Activation of a specific signal transduction pathway in the cell depends on various factors and may be altered when normal tissue becomes neoplastic. Laminin signals via multiple signal transduction pathways involving various components such as G-proteins, intracellular calcium, phospholipase D, mitogen activated protein kinases, phosphatases, focal adhesion kinase, small GTPases of the Rho family, and cytoskeleton components. This review focuses on the role of laminin in tumor progression, its signaling via the non-integrin 67kDa laminin receptor and via integrins and the reciprocal relations between these receptors in certain tumors.

Research paper thumbnail of Expression of the 67 kDa laminin receptor and the α6 integrin subunit in serous ovarian carcinoma

Clinical and …, 2003

Vered Givant-Horwitz1, Ben Davidson2, Gregg van de Putte3, Hiep Phuc Dong2, Iris Goldberg4, Sivan... more Vered Givant-Horwitz1, Ben Davidson2, Gregg van de Putte3, Hiep Phuc Dong2, Iris Goldberg4, Sivan Amir1, Gunnar B. Kristensen3 & Reuven Reich1,5 1Department of Pharmacology and Experimental Therapeutics, Faculty of Medicine, Hebrew University, Jerusalem, ...

Research paper thumbnail of Caveolin-1 Expression in Ovarian Carcinoma Is MDR1 Independent

American Journal of Clinical Pathology, 2002

We studied the role of caveolin-1 in tumor progression and prognosis in serous ovarian carcinoma ... more We studied the role of caveolin-1 in tumor progression and prognosis in serous ovarian carcinoma and the association between caveolin-1 and MDR1 expression. The study involved immunohistochemical analysis for caveolin-1 and P-glycoprotein (P-gp) expression in 75 effusions and 90 solid lesions from ovarian and primary peritoneal carcinoma; in situ hybridization for MDR1 messenger RNA (mRNA) expression in 62 effusions and all 90 tumors; and reverse transcription-polymerase chain reaction (RT-PCR) for caveolin-1 mRNA expression in 23 effusions. Immunohistochemical analysis localized caveolin-1 to the cell membrane in 43 effusions and 24 tumors. P-gp membrane expression was detected in 14 effusions and 11 tumors; MDR1 mRNA, in 20 effusions and 30 tumors. Caveolin-1 mRNA was expressed in 19 effusions. Caveolin-1 protein expression showed no association with that of P-gp protein or MDR1 mRNA. The expression of all markers was similar in carcinoma cells in pleural and peritoneal effusions. Caveolin-1 is a novel diagnostic marker for effusions; expression is moderately elevated in tumor cells in effusions, possibly owing to altered signal transduction and metabolism in cancer cells at this site. Expression seems MDR1 independent.

Research paper thumbnail of Expression of Membrane-Type 1, 2, and 3 Matrix Metalloproteinases Messenger RNA in Ovarian Carcinoma Cells in Serous Effusions

American Journal of Clinical Pathology, 2001

We studied the levels of matrix metalloproteinase (MMP)-2, membrane-type (MT)1-MMP, MT2-MMP, and ... more We studied the levels of matrix metalloproteinase (MMP)-2, membrane-type (MT)1-MMP, MT2-MMP, and MT3-MMP in 43 malignant pleural and peritoneal effusions using reverse transcription-polymerase chain reaction (RT-PCR) and cellular localization of MT1-MMP in 66 effusion specimens and 85 corresponding primary and metastatic tumors using messenger RNA (mRNA) in situ hybridization (ISH). In 43 effusions, MMP-2 mRNA was detected in 37, MT1-MMP in 25, and MT2-MMP in 32. Expression of MT1-MMP and MT2-MMP was found in 21 specimens; in 16 MT-MMP-positive specimens, mRNA for only 1 of 2 enzymes was expressed. MT3-MMP mRNA was not detected. High levels of MMP-2 mRNA were detected more often in effusions with high MT1-MMP and/or MT2-MMP mRNA expression. Using ISH, MT1-MMP mRNA was localized to cancer cells in 27 of 58 malignant effusions; focal signals were detected in mesothelial cells in 7 of 42. MT1-MMP was localized to tumor cells in 32 of 85 primary and metastatic solid lesions, and stromal cells expressed MT1-MMP in 3. Tumor cell MT1-MMP expression in effusion specimens did not differ from primary or metastatic lesions. MT-MMP expression in tumor cells in effusions showed no association with effusion site or tumor type using ISH and RT-PCR.

Research paper thumbnail of Matrix metalloproteinases (MMP), EMMPRIN (extracellular matrix metalloproteinase inducer) and mitogen-activated protein kinases (MAPK): co-expression in metastatic serous ovarian carcinoma

Clinical & experimental metastasis, 2003

Activation or suppression of intracellular signaling via the mitogen-activated protein kinase (MA... more Activation or suppression of intracellular signaling via the mitogen-activated protein kinase (MAPK) family has been linked to expression of matrix metalloproteinases (MMP) in experimental models, but this association has not been demonstrated in clinical material. The objective of this study was to investigate the possible association between expression and activity of MMP, expression of the MMP inducer EMMPRIN, and the expression (level) and phosphorylation status (activity) of the extracellular-regulated kinase (ERK), c-Jun amino-terminal kinase (JNK) and high osmolarity glycerol response kinase (p38) in effusions from patients diagnosed with serous ovarian carcinoma. MAPK level and activity were studied in 55 effusions using immunoblotting. MMP-1, MMP-2, MMP-9 and EMMPRIN expression was studied using immunocytochemistry (ICC) and mRNA in situ hybridization (ISH). The gelatinolytic activity of MMP-2 and MMP-9 was measured by zymography. ERK and phospho-ERK (p-ERK) were detected i...