Tibor Krenács - Academia.edu (original) (raw)
Papers by Tibor Krenács
Cell Stress and Chaperones, 2014
In modulated electrohyperthermia (mEHT) the enrichment of electric field and the concomitant heat... more In modulated electrohyperthermia (mEHT) the enrichment of electric field and the concomitant heat can selectively induce cell death in malignant tumors as a result of elevated glycolysis, lactate production (Warburg effect), and reduced electric impedance in cancer compared to normal tissues. Earlier, we showed in HT29 colorectal cancer xenografts that the mEHTprovoked programmed cell death was dominantly caspase independent and driven by apoptosis inducing factor activation. Using this model here, we studied the mEHT-related cell stress 0-, 1-, 4-, 8-, 14-, 24-, 48-, 72-, 120-, 168-and 216-h post-treatment by focusing on damage-associated molecular pattern (DAMP) signals.
Pathology & Oncology Research, Apr 20, 2020
Up-regulation of the long non-coding RNA LINC00152 can contribute to cancer development, prolifer... more Up-regulation of the long non-coding RNA LINC00152 can contribute to cancer development, proliferation and invasion, including colorectal cancer, however, its mechanism of action in colorectal carcinogenesis and progression is only insufficiently understood. In this work we correlated LINC00152 expression with promoter DNA methylation changes in colorectal tissues along the normal-adenoma-carcinoma sequence and studied the effects of LINC00152 silencing on the cell cycle regulation and on the whole transcriptome in colon carcinoma cells using cell and molecular biology techniques. LINC00152 was significantly up-regulated in adenoma and colorectal cancer (p < 0.001) compared to normal samples, which was confirmed by real-time PCR and in situ hybridization. LINC00152 promoter hypomethylation detected in colorectal cancer (p < 0.01) was strongly correlated with increased LINC00152 expression (r=-0.90). Silencing of LINC00152 significantly suppressed cell growth, induced apoptosis and decreased cyclin D1 expression (p < 0.05). Whole transcriptome analysis of LINC00152-silenced cells revealed significant down-regulation of oncogenic and metastasis promoting genes (e.g. YES proto-oncogene 1, PORCN porcupine Oacyltransferase), and up-regulation of tumour suppressor genes (e.g. DKK1 dickkopf WNT signalling pathway inhibitor 1, PERP p53 apoptosis effector) (adjusted p < 0.05). Pathway analysis confirmed the LINC00152-related activation of oncogenic molecular pathways including those driven by PI3K/Akt, Ras, WNT, TP53, Notch and ErbB. Our results suggest that promoter hypomethylation related overexpression of LINC00152 can contribute to the pathogenesis of colorectal cancer by facilitating cell progression through the up-regulation of several oncogenic and metastasis promoting pathway elements.
Human Pathology, Jul 1, 2017
Although several antibodies are available for immunohistochemical (IHC) detection of Ki-67, even ... more Although several antibodies are available for immunohistochemical (IHC) detection of Ki-67, even the most commonly used MIB-1 has not been validated yet. Our aim was to compare 5 commercially available antibodies for detection of Ki-67 in terms of agreement and their ability in predicting prognosis of breast cancer. Tissue microarrays were constructed from 378 breast cancer patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; representative formalin-fixed paraffin-embedded tumor blocks. Five antibodies were used to detect Ki-67 expression: MIB-1-using chromogenic detection and immunofluorescent labeled (IF) MIB1-, SP-6, 30-9, poly and B56. Semi-quantitative assessment was performed by two pathologists independently on digitized slides. To compare the 5 antibodies, intra-class correlation (ICC) and concordance correlation coefficient (CCC) were used. All the antibodies but MIB-1IF (at 20% and 30% thresholds, P=.993, P=.342, respectively) and B56 (at 30% threshold, P=.288) separated high and low risk patient groups. However, there was a significant difference (p values for all comparisons≤0.005) and moderate concordance (ICC=0.645) between their Ki67 labeling index (LI) scores. The highest concordance was found between MIB-1 and poly (CCC=0.785) antibodies. None of the antibodies except Ki67 LI as detected by poly (P=.031) at 20% threshold, and lymph node status (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.001) were significantly linked to disease free survival in multivariate analysis. At 30% threshold, this was reduced to lymph node status (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.001) alone. Our results showed that there are considerable differences between the different Ki67 antibodies in their capacity to detect proliferating tumor cells and to separate low and high-risk breast cancer patient groups.
Pathology & Oncology Research, Mar 14, 2022
In myelofibrosis, pathologically enhanced extracellular matrix production due to aberrant cytokin... more In myelofibrosis, pathologically enhanced extracellular matrix production due to aberrant cytokine signalling and clonal megakaryocyte functions result(s) in impaired hemopoiesis. Disease progression is still determined by detecting reticulin and collagen fibrosis with Gomori's silver impregnation. Here, we tested whether the expression growth related biomarkers L-NGFR/CD271, phospho-ERK1-2 and CXCL12 can be linked to the functional activation of bone marrow stromal cells during primary myelofibrosis progression. Immunoscores for all tested biomarkers showed varying strength of positive statistical correlation with the silver impregnation based myelofibrosis grades. The intimate relationship between spindle shaped stromal cells positive for all three markers and aberrant megakaryocytes was likely to reflect their functional cooperation. L-NGFR reaction was restricted to bone marrow stromal cells and revealed the whole length of their processes. Also, L-NGFR positive cells showed the most intersections, the best statistical correlations with myelofibrosis grades and the strongest interrater agreements. CXCL12 reaction highlighted stromal cell bodies and a weak extracellular staining in line with its constitutive release. Phospho-ERK1-2 reaction showed a similar pattern to CXCL12 in stromal cells with an additional nuclear staining in agreement with its role as a transcription factor. Both p-ERK1-2 and CXCL12 were also expressed at a moderate level in sinus endothelial cells. Connexin 43 gap junction communication channels, known to be required for CXCL12 release to maintain stem cell niche, were also expressed progressively in the myelofibrotic stromal network as a support of compartmental functions. Our results suggest that, diverse growth related pathways are activated in the functionally coupled bone marrow stromal cells during myelofibrosis progression. L-NGFR expression can be a useful biological marker of stromal cell activation which deserves diagnostic consideration for complementing Gomori's silver impregnation.
Zeitschrift Fur Gastroenterologie, May 1, 2011
Frontiers in Oncology
The basis of the conventional gene-centric view on tumor evolution is that vertically inherited m... more The basis of the conventional gene-centric view on tumor evolution is that vertically inherited mutations largely define the properties of tumor cells. In recent years, however, accumulating evidence shows that both the tumor cells and their microenvironment may acquire external, non-vertically inherited genetic properties via horizontal gene transfer (HGT), particularly through small extracellular vesicles (sEVs). Many phases of sEV-mediated HGT have been described, such as DNA packaging into small vesicles, their release, uptake by recipient cells, and incorporation of sEV-DNA into the recipient genome to modify the phenotype and properties of cells. Recent techniques in sEV separation, genome sequencing and editing, as well as the identification of new secretion mechanisms, shed light on a number of additional details of this phenomenon. Here, we discuss the key features of this form of gene transfer and make an attempt to draw relevant conclusions on the contribution of HGT to t...
Pathology and Oncology Research
This text is based on the recommendations accepted by the 4th Hungarian Consensus Conference on B... more This text is based on the recommendations accepted by the 4th Hungarian Consensus Conference on Breast Cancer, modified on the basis of the international consultation and conference within the frames of the Central-Eastern European Academy of Oncology. The recommendations cover non-operative, intraoperative and postoperative diagnostics, determination of prognostic and predictive markers and the content of cytology and histology reports. Furthermore, they address some specific issues such as the current status of multigene molecular markers, the role of pathologists in clinical trials and prerequisites for their involvement, and some remarks about the future.
Analytical Cellular Pathology, 2009
Background: As most colorectal cancers (CRC) develop from villous adenomas, studying alterations ... more Background: As most colorectal cancers (CRC) develop from villous adenomas, studying alterations in gene expression profiles across the colorectal adenoma–dysplasia–carcinoma sequence may yield potential biomarkers of disease progression.Methods: Total RNA was extracted, amplified, and biotinylated from colonic biopsies of 15 patients with CRC, 15 with villous adenoma and 8 normal controls. Gene expression profiles were evaluated using HGU133Plus2.0 microarrays and disease progression associated data were validated with RT-PCR. The potential biomarkers were also tested at the protein level using tissue microarray samples of 103 independent and 16 overlapping patients.Results: 17 genes were validated to show sequentially altered expression at mRNA level through the normal–adenoma–dysplasia–carcinoma progression. Prostaglandin-D2 receptor (PTGDR) and amnionless homolog (AMN) genes revealed gradually decreasing expression while the rest of 15 genes including osteonectin, osteopontin, c...
Magyar onkologia, 2019
Our objective was to develop an electromagnetic tumor therapy device in a consortial cooperation ... more Our objective was to develop an electromagnetic tumor therapy device in a consortial cooperation between Semmelweis University and Oncotherm Ltd., to provide data and contribute to the development of the next generation of devices through preclinical, clinical and developmental modules via in vivo, in vitro studies, and patient treatments. Our numerous preclinical studies support the efficacy of mEHT. Clinical treatments were performed in 181 patients with inoperable and/or oligometastatic solid tumors. The protocols were developed, an international guideline was completed, and the planned steps of device development were realized. By optimizing previous selective RF techniques based on recent research findings, we can provide the most modern evidence-based treatment in the future.
Cancers, 2019
The incidence of malignant melanoma, one of the deadliest cancers, continues to increase. Here we... more The incidence of malignant melanoma, one of the deadliest cancers, continues to increase. Here we tested connexin (Cx) expression in primary melanocytes, melanoma cell lines and in a common nevus, dysplastic nevus, and thin, thick, and metastatic melanoma tumor progression series involving the tumor microenvironment by utilizing in silico analysis, qRT-PCR, immunocyto-/histochemistry and dye transfer tests. Primary melanocytes expressed GJA1/Cx43, GJA3/Cx46 and low levels of GJB2/Cx26 and GJC3/Cx30.2 transcripts. In silico data revealed downregulation of GJA1/Cx43 and GJB2/Cx26 mRNA, in addition to upregulated GJB1/Cx32, during melanoma progression. In three melanoma cell lines, we also showed the loss of GJA1/Cx43 and the differential expression of GJB1/Cx32, GJB2/Cx26, GJA3/Cx46 and GJC3/Cx30.2. The dominantly paranuclear localization of connexin proteins explained the ~10–90 times less melanoma cell coupling compared to melanocytes. In melanocytic tumor tissues, we confirmed the ...
Pathology & Oncology Research, 2019
We aimed to analyze the expression of cell-cycle regulation markersminichromosome maintenance pro... more We aimed to analyze the expression of cell-cycle regulation markersminichromosome maintenance protein 2 (MCM2), Ki-67, Cyclin-A and phosphohistone-H3 (PHH3) − in pre-treatment core-biopsy samples of breast carcinomas in correlation with known predictive and prognostic factors. Totally 52 core biopsy samples obtained prior to neoadjuvant therapy were analyzed. Immunohistochemistry was performed to analyze the expression of MCM2, Ki-67, Cyclin A and PHH3, which were correlated with the following clinicopathological parameters: clinical TNM, tumor grade, biological subtype, the presence of tumor infiltrating lymphocytes (TIL), pathological tumor response rate to the neoadjuvant therapy and patient survival. All investigated markers showed higher expression in high grade and in triple negative tumors (p < 0.01 and p < 0.05, respectively). Hormone receptor negative tumors showed significantly higher expression of Ki-67 (p < 0.01), MCM2 (p < 0.01) and Cyclin A (p < 0.01) than hormone receptor positive ones. Tumors with increased TIL showed significantly higher Ki-67 expression (p = 0.04). Pattern analysis suggested that novel cell-cycle marker-based subgrouping reveals predictive and prognostic potential. Tumors with high MCM2, Cyclin A or PHH3 expression showed significantly higher rate of pathological complete remission. Tumors with early relapse (progression-free survival ≤2 years) and shortened overall survival also show a higher rate of proliferation. Our cell cycle marker (Ki-67, MCM2, Cyclin A, PHH3) based testing could identify tumors with worse prognosis, but with a favorable response to primary systemic therapy. The pattern of cell-cycle activity could also be useful for predicting early relapse, but our findings need to be further substantiated in larger patient cohorts.
International Journal of Molecular Sciences, 2019
Modulated electrohyperthermia (mEHT), an innovative complementary technique of radio-, chemo-, an... more Modulated electrohyperthermia (mEHT), an innovative complementary technique of radio-, chemo-, and targeted oncotherapy modalities, can induce tumor apoptosis and contribute to a secondary immune-mediated cancer death. Here, we tested the efficiency of high-fever range (~42 °C) mEHT on B16F10 melanoma both in cell culture and allograft models. In vivo, mEHT treatment resulted in significant tumor size reduction when repeated three times, and induced major stress response as indicated by upregulated cytoplasmic and cell membrane hsp70 levels. Despite the increased PUMA and apoptosis-inducing factor 1, and moderate rise in activated-caspase-3, apoptosis was not significant. However, phospho-H2AX indicated DNA double-strand breaks, which upregulated p53 protein and its downstream cyclin-dependent kinase inhibitors p21waf1 and p27kip. Combined in vitro treatment with mEHT and the p53 activator nutlin-3a additively reduced cell viability compared to monotherapies. Though mEHT promoted th...
Virchows Archiv, 2016
We aimed to analyze to what extent expression of four cell cycle regulation markers-minichromosom... more We aimed to analyze to what extent expression of four cell cycle regulation markers-minichromosome maintenance protein (MCM2), Ki-67, cyclin A, and phosphohistone-H3 (PHH3)-predict response to primary systemic therapy in terms of pathological complete remission (pCR). In search of an accurate and reproducible scoring method, we compared computer-assisted (CA) and routine visual assessment (VA) of immunoreactivity. We included 57 patients with breast cancer in the study. The cell cycle markers were detected using immunohistochemistry on pre-therapy core biopsy samples. Parallel CA (validated by manual labeling) and standard VA were performed and compared for diagnostic agreement and predictive value for pCR. CA and VA results were dichotomized based on receiver operating characteristic analysis defined optimal cutoff values. "High" was defined by staining scores above the optimal cutoff, while "low" had staining scores below the optimal cutoff. The CA method resulted in significantly lower values for Ki-67 and MCM2 compared to VA (mean difference, −3.939 and −4.323). Diagnostic agreement was highest for cyclin A and PHH3 (−0.586 and −0.666, respectively). Regardless of the method (CA/VA) used, all tested markers were predictive of pCR. Optimal cutoff based dichotomization improved diagnostic agreement between the CA and VA methods for every marker, in particular for MCM2 (κ = 1, p < 0.000). Cyclin A displayed excellent agreement (κ = 0.925; p < 0.000), while Ki-67 and PHH3 showed good agreement (κ = 0.789, p < 0.000 and κ = 0.794, p < 0.000, respectively). We found all cell cycle markers (Ki-67, MCM2, cyclin A, and PHH3) predictive of pCR. Diagnostic agreement between CA and VA was better at lower staining scores but improved after optimal cutoff based dichotomization.
Virchows Archiv, 2016
The incidence of head and neck squamous cell carcinomas is still growing, and the long-term progn... more The incidence of head and neck squamous cell carcinomas is still growing, and the long-term prognosis of advanced disease remains poor. Only a fraction of head and neck cancers are sensitive to the EGFR-inhibitor cetuximab, which is the only registered targeted therapy available today. In several cancers, gene copy number alterations of MET and PIK3CA have been found to be prognostic and predictive for therapy response. The aim of this study was to systematically analyze in head and neck cancers the pathological characteristics and prognostic significance of copy number changes of MET and PIK3CA genes. MET and PIK3CA copy numbers were analyzed by fluorescence in situ hybridization in tumor samples of 152 patients. Expression of EGFR, p16, and Ki67 was studied by immunohistochemistry. High polysomy of PIK3CA (chromosome 3) was found in 20 % of cases and amplification in 4.5 %. Regarding MET, 35 % of cases showed low or high polysomy of the gene (chromosome 7), while no intra-chromosomal amplification of MET was detected. PIK3CA copy number gain (high polysomy or amplification) was significantly associated with shorter diseasespecific survival, larger tumor volume, and lower p16 expression. MET copy number gain (low or high polysomy) in tumors was significantly associated with shorter disease-specific survival and lower level of EGFR. PIK3CA and MET may play an important role in oncogenesis of certain specific subtypes of head and neck cancer. There is an urgent need for the development of novel targeted therapies against these tumors associated with poor prognosis. Keywords MET. PIK3CA. CNG (copy number gain). Head and neck cancer (HNC)
Pancreatology
Introduction: Molecular pharmacological studies of the somatostatin analogue (TT-232 (Biostatin L... more Introduction: Molecular pharmacological studies of the somatostatin analogue (TT-232 (Biostatin Ltd.)/CAP-232 Caprion Pharmaceuticals Inc.) have revealed that the well-known tumour marker of pancreatic cancer, the M2 isotype of the key metabolic enzyme pyruvate kinase (M2PK) is also a potential molecular target of novel targeted therapies. Objectives: Determination of M2PK expression level of M2PK may be important in the personalized use of these drugs in the near future. Materials and Methods: We have determined the local expression of M2PK by qPCR assay and immunohystochemistry in surgical biopsies, and compared the results to the M2PK protein levels in the peripheral blood by ELISA based assay in the same patients and control individuals. Results: We found that peripheral blood M2PK protein level is a highly sensitive and specific tumour marker of pancreatic cancer but does not directly correlate with the local expression levels of M2PK. Distinction of different isoforms of PK in...
Conference Papers in Medicine, 2013
Background. Modulated electrohyperthermia (mEHT) is a noninvasive technique for targeted tumor tr... more Background. Modulated electrohyperthermia (mEHT) is a noninvasive technique for targeted tumor treatment. Method. HT29 human colorectal carcinoma cell line xenografted to both femoral regions of BalbC/nu/nu mice was treated with a single shot OTM treatment. Histomorphologic, immunohistochemical analysis TUNEL assay, and R&D Apoptosis array were performed on tissue samples. Results. mEHT caused a selective tumor demolition. An upregulation of TRAIL-R2 and FAS was observed. Cleaved caspase-3 positive cells appear at the tumor periphery. Cytochrome c and AIF release was observed in line with massive TUNEL positivity. Conclusion. In HT29 colorectal cancer xenograft, mEHT caused massive caspase independent cell death.
Anticancer research, 2009
The effect of gonadotropin-releasing hormone (GnRH) analogs on prostate carcinoma is partly a res... more The effect of gonadotropin-releasing hormone (GnRH) analogs on prostate carcinoma is partly a result of breaking the pituitary-gonadal axis, and partly the direct action on tumor cells expressing the GnRH receptor (GnRHR). The aim of this study was to detect the extent of correlation between the expression of GnRHR and also the androgen receptor (AR) and the efficacy of total androgen blockade (TAB). Needle biopsy samples of twenty advanced prostate carcinoma patients were investigated histologically regarding Gleason score, AR and GnRHR status of the tumor cells. An affinity purified polyclonal antibody reacting with GnRHR and a monoclonal antibody for AR were applied for immunoperoxidase reactions. TAB was started in each case. Pathological, radiological and laboratory-prostate-specific antigen (PSA) data obtained before the start of TAB and survival, PSA values, and radiological findings after three years of TAB were related to AR and GnRHR. Regarding the clinical, radiological a...
Cell Stress and Chaperones, 2014
In modulated electrohyperthermia (mEHT) the enrichment of electric field and the concomitant heat... more In modulated electrohyperthermia (mEHT) the enrichment of electric field and the concomitant heat can selectively induce cell death in malignant tumors as a result of elevated glycolysis, lactate production (Warburg effect), and reduced electric impedance in cancer compared to normal tissues. Earlier, we showed in HT29 colorectal cancer xenografts that the mEHTprovoked programmed cell death was dominantly caspase independent and driven by apoptosis inducing factor activation. Using this model here, we studied the mEHT-related cell stress 0-, 1-, 4-, 8-, 14-, 24-, 48-, 72-, 120-, 168-and 216-h post-treatment by focusing on damage-associated molecular pattern (DAMP) signals.
Pathology & Oncology Research, Apr 20, 2020
Up-regulation of the long non-coding RNA LINC00152 can contribute to cancer development, prolifer... more Up-regulation of the long non-coding RNA LINC00152 can contribute to cancer development, proliferation and invasion, including colorectal cancer, however, its mechanism of action in colorectal carcinogenesis and progression is only insufficiently understood. In this work we correlated LINC00152 expression with promoter DNA methylation changes in colorectal tissues along the normal-adenoma-carcinoma sequence and studied the effects of LINC00152 silencing on the cell cycle regulation and on the whole transcriptome in colon carcinoma cells using cell and molecular biology techniques. LINC00152 was significantly up-regulated in adenoma and colorectal cancer (p < 0.001) compared to normal samples, which was confirmed by real-time PCR and in situ hybridization. LINC00152 promoter hypomethylation detected in colorectal cancer (p < 0.01) was strongly correlated with increased LINC00152 expression (r=-0.90). Silencing of LINC00152 significantly suppressed cell growth, induced apoptosis and decreased cyclin D1 expression (p < 0.05). Whole transcriptome analysis of LINC00152-silenced cells revealed significant down-regulation of oncogenic and metastasis promoting genes (e.g. YES proto-oncogene 1, PORCN porcupine Oacyltransferase), and up-regulation of tumour suppressor genes (e.g. DKK1 dickkopf WNT signalling pathway inhibitor 1, PERP p53 apoptosis effector) (adjusted p < 0.05). Pathway analysis confirmed the LINC00152-related activation of oncogenic molecular pathways including those driven by PI3K/Akt, Ras, WNT, TP53, Notch and ErbB. Our results suggest that promoter hypomethylation related overexpression of LINC00152 can contribute to the pathogenesis of colorectal cancer by facilitating cell progression through the up-regulation of several oncogenic and metastasis promoting pathway elements.
Human Pathology, Jul 1, 2017
Although several antibodies are available for immunohistochemical (IHC) detection of Ki-67, even ... more Although several antibodies are available for immunohistochemical (IHC) detection of Ki-67, even the most commonly used MIB-1 has not been validated yet. Our aim was to compare 5 commercially available antibodies for detection of Ki-67 in terms of agreement and their ability in predicting prognosis of breast cancer. Tissue microarrays were constructed from 378 breast cancer patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; representative formalin-fixed paraffin-embedded tumor blocks. Five antibodies were used to detect Ki-67 expression: MIB-1-using chromogenic detection and immunofluorescent labeled (IF) MIB1-, SP-6, 30-9, poly and B56. Semi-quantitative assessment was performed by two pathologists independently on digitized slides. To compare the 5 antibodies, intra-class correlation (ICC) and concordance correlation coefficient (CCC) were used. All the antibodies but MIB-1IF (at 20% and 30% thresholds, P=.993, P=.342, respectively) and B56 (at 30% threshold, P=.288) separated high and low risk patient groups. However, there was a significant difference (p values for all comparisons≤0.005) and moderate concordance (ICC=0.645) between their Ki67 labeling index (LI) scores. The highest concordance was found between MIB-1 and poly (CCC=0.785) antibodies. None of the antibodies except Ki67 LI as detected by poly (P=.031) at 20% threshold, and lymph node status (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.001) were significantly linked to disease free survival in multivariate analysis. At 30% threshold, this was reduced to lymph node status (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.001) alone. Our results showed that there are considerable differences between the different Ki67 antibodies in their capacity to detect proliferating tumor cells and to separate low and high-risk breast cancer patient groups.
Pathology & Oncology Research, Mar 14, 2022
In myelofibrosis, pathologically enhanced extracellular matrix production due to aberrant cytokin... more In myelofibrosis, pathologically enhanced extracellular matrix production due to aberrant cytokine signalling and clonal megakaryocyte functions result(s) in impaired hemopoiesis. Disease progression is still determined by detecting reticulin and collagen fibrosis with Gomori's silver impregnation. Here, we tested whether the expression growth related biomarkers L-NGFR/CD271, phospho-ERK1-2 and CXCL12 can be linked to the functional activation of bone marrow stromal cells during primary myelofibrosis progression. Immunoscores for all tested biomarkers showed varying strength of positive statistical correlation with the silver impregnation based myelofibrosis grades. The intimate relationship between spindle shaped stromal cells positive for all three markers and aberrant megakaryocytes was likely to reflect their functional cooperation. L-NGFR reaction was restricted to bone marrow stromal cells and revealed the whole length of their processes. Also, L-NGFR positive cells showed the most intersections, the best statistical correlations with myelofibrosis grades and the strongest interrater agreements. CXCL12 reaction highlighted stromal cell bodies and a weak extracellular staining in line with its constitutive release. Phospho-ERK1-2 reaction showed a similar pattern to CXCL12 in stromal cells with an additional nuclear staining in agreement with its role as a transcription factor. Both p-ERK1-2 and CXCL12 were also expressed at a moderate level in sinus endothelial cells. Connexin 43 gap junction communication channels, known to be required for CXCL12 release to maintain stem cell niche, were also expressed progressively in the myelofibrotic stromal network as a support of compartmental functions. Our results suggest that, diverse growth related pathways are activated in the functionally coupled bone marrow stromal cells during myelofibrosis progression. L-NGFR expression can be a useful biological marker of stromal cell activation which deserves diagnostic consideration for complementing Gomori's silver impregnation.
Zeitschrift Fur Gastroenterologie, May 1, 2011
Frontiers in Oncology
The basis of the conventional gene-centric view on tumor evolution is that vertically inherited m... more The basis of the conventional gene-centric view on tumor evolution is that vertically inherited mutations largely define the properties of tumor cells. In recent years, however, accumulating evidence shows that both the tumor cells and their microenvironment may acquire external, non-vertically inherited genetic properties via horizontal gene transfer (HGT), particularly through small extracellular vesicles (sEVs). Many phases of sEV-mediated HGT have been described, such as DNA packaging into small vesicles, their release, uptake by recipient cells, and incorporation of sEV-DNA into the recipient genome to modify the phenotype and properties of cells. Recent techniques in sEV separation, genome sequencing and editing, as well as the identification of new secretion mechanisms, shed light on a number of additional details of this phenomenon. Here, we discuss the key features of this form of gene transfer and make an attempt to draw relevant conclusions on the contribution of HGT to t...
Pathology and Oncology Research
This text is based on the recommendations accepted by the 4th Hungarian Consensus Conference on B... more This text is based on the recommendations accepted by the 4th Hungarian Consensus Conference on Breast Cancer, modified on the basis of the international consultation and conference within the frames of the Central-Eastern European Academy of Oncology. The recommendations cover non-operative, intraoperative and postoperative diagnostics, determination of prognostic and predictive markers and the content of cytology and histology reports. Furthermore, they address some specific issues such as the current status of multigene molecular markers, the role of pathologists in clinical trials and prerequisites for their involvement, and some remarks about the future.
Analytical Cellular Pathology, 2009
Background: As most colorectal cancers (CRC) develop from villous adenomas, studying alterations ... more Background: As most colorectal cancers (CRC) develop from villous adenomas, studying alterations in gene expression profiles across the colorectal adenoma–dysplasia–carcinoma sequence may yield potential biomarkers of disease progression.Methods: Total RNA was extracted, amplified, and biotinylated from colonic biopsies of 15 patients with CRC, 15 with villous adenoma and 8 normal controls. Gene expression profiles were evaluated using HGU133Plus2.0 microarrays and disease progression associated data were validated with RT-PCR. The potential biomarkers were also tested at the protein level using tissue microarray samples of 103 independent and 16 overlapping patients.Results: 17 genes were validated to show sequentially altered expression at mRNA level through the normal–adenoma–dysplasia–carcinoma progression. Prostaglandin-D2 receptor (PTGDR) and amnionless homolog (AMN) genes revealed gradually decreasing expression while the rest of 15 genes including osteonectin, osteopontin, c...
Magyar onkologia, 2019
Our objective was to develop an electromagnetic tumor therapy device in a consortial cooperation ... more Our objective was to develop an electromagnetic tumor therapy device in a consortial cooperation between Semmelweis University and Oncotherm Ltd., to provide data and contribute to the development of the next generation of devices through preclinical, clinical and developmental modules via in vivo, in vitro studies, and patient treatments. Our numerous preclinical studies support the efficacy of mEHT. Clinical treatments were performed in 181 patients with inoperable and/or oligometastatic solid tumors. The protocols were developed, an international guideline was completed, and the planned steps of device development were realized. By optimizing previous selective RF techniques based on recent research findings, we can provide the most modern evidence-based treatment in the future.
Cancers, 2019
The incidence of malignant melanoma, one of the deadliest cancers, continues to increase. Here we... more The incidence of malignant melanoma, one of the deadliest cancers, continues to increase. Here we tested connexin (Cx) expression in primary melanocytes, melanoma cell lines and in a common nevus, dysplastic nevus, and thin, thick, and metastatic melanoma tumor progression series involving the tumor microenvironment by utilizing in silico analysis, qRT-PCR, immunocyto-/histochemistry and dye transfer tests. Primary melanocytes expressed GJA1/Cx43, GJA3/Cx46 and low levels of GJB2/Cx26 and GJC3/Cx30.2 transcripts. In silico data revealed downregulation of GJA1/Cx43 and GJB2/Cx26 mRNA, in addition to upregulated GJB1/Cx32, during melanoma progression. In three melanoma cell lines, we also showed the loss of GJA1/Cx43 and the differential expression of GJB1/Cx32, GJB2/Cx26, GJA3/Cx46 and GJC3/Cx30.2. The dominantly paranuclear localization of connexin proteins explained the ~10–90 times less melanoma cell coupling compared to melanocytes. In melanocytic tumor tissues, we confirmed the ...
Pathology & Oncology Research, 2019
We aimed to analyze the expression of cell-cycle regulation markersminichromosome maintenance pro... more We aimed to analyze the expression of cell-cycle regulation markersminichromosome maintenance protein 2 (MCM2), Ki-67, Cyclin-A and phosphohistone-H3 (PHH3) − in pre-treatment core-biopsy samples of breast carcinomas in correlation with known predictive and prognostic factors. Totally 52 core biopsy samples obtained prior to neoadjuvant therapy were analyzed. Immunohistochemistry was performed to analyze the expression of MCM2, Ki-67, Cyclin A and PHH3, which were correlated with the following clinicopathological parameters: clinical TNM, tumor grade, biological subtype, the presence of tumor infiltrating lymphocytes (TIL), pathological tumor response rate to the neoadjuvant therapy and patient survival. All investigated markers showed higher expression in high grade and in triple negative tumors (p < 0.01 and p < 0.05, respectively). Hormone receptor negative tumors showed significantly higher expression of Ki-67 (p < 0.01), MCM2 (p < 0.01) and Cyclin A (p < 0.01) than hormone receptor positive ones. Tumors with increased TIL showed significantly higher Ki-67 expression (p = 0.04). Pattern analysis suggested that novel cell-cycle marker-based subgrouping reveals predictive and prognostic potential. Tumors with high MCM2, Cyclin A or PHH3 expression showed significantly higher rate of pathological complete remission. Tumors with early relapse (progression-free survival ≤2 years) and shortened overall survival also show a higher rate of proliferation. Our cell cycle marker (Ki-67, MCM2, Cyclin A, PHH3) based testing could identify tumors with worse prognosis, but with a favorable response to primary systemic therapy. The pattern of cell-cycle activity could also be useful for predicting early relapse, but our findings need to be further substantiated in larger patient cohorts.
International Journal of Molecular Sciences, 2019
Modulated electrohyperthermia (mEHT), an innovative complementary technique of radio-, chemo-, an... more Modulated electrohyperthermia (mEHT), an innovative complementary technique of radio-, chemo-, and targeted oncotherapy modalities, can induce tumor apoptosis and contribute to a secondary immune-mediated cancer death. Here, we tested the efficiency of high-fever range (~42 °C) mEHT on B16F10 melanoma both in cell culture and allograft models. In vivo, mEHT treatment resulted in significant tumor size reduction when repeated three times, and induced major stress response as indicated by upregulated cytoplasmic and cell membrane hsp70 levels. Despite the increased PUMA and apoptosis-inducing factor 1, and moderate rise in activated-caspase-3, apoptosis was not significant. However, phospho-H2AX indicated DNA double-strand breaks, which upregulated p53 protein and its downstream cyclin-dependent kinase inhibitors p21waf1 and p27kip. Combined in vitro treatment with mEHT and the p53 activator nutlin-3a additively reduced cell viability compared to monotherapies. Though mEHT promoted th...
Virchows Archiv, 2016
We aimed to analyze to what extent expression of four cell cycle regulation markers-minichromosom... more We aimed to analyze to what extent expression of four cell cycle regulation markers-minichromosome maintenance protein (MCM2), Ki-67, cyclin A, and phosphohistone-H3 (PHH3)-predict response to primary systemic therapy in terms of pathological complete remission (pCR). In search of an accurate and reproducible scoring method, we compared computer-assisted (CA) and routine visual assessment (VA) of immunoreactivity. We included 57 patients with breast cancer in the study. The cell cycle markers were detected using immunohistochemistry on pre-therapy core biopsy samples. Parallel CA (validated by manual labeling) and standard VA were performed and compared for diagnostic agreement and predictive value for pCR. CA and VA results were dichotomized based on receiver operating characteristic analysis defined optimal cutoff values. "High" was defined by staining scores above the optimal cutoff, while "low" had staining scores below the optimal cutoff. The CA method resulted in significantly lower values for Ki-67 and MCM2 compared to VA (mean difference, −3.939 and −4.323). Diagnostic agreement was highest for cyclin A and PHH3 (−0.586 and −0.666, respectively). Regardless of the method (CA/VA) used, all tested markers were predictive of pCR. Optimal cutoff based dichotomization improved diagnostic agreement between the CA and VA methods for every marker, in particular for MCM2 (κ = 1, p < 0.000). Cyclin A displayed excellent agreement (κ = 0.925; p < 0.000), while Ki-67 and PHH3 showed good agreement (κ = 0.789, p < 0.000 and κ = 0.794, p < 0.000, respectively). We found all cell cycle markers (Ki-67, MCM2, cyclin A, and PHH3) predictive of pCR. Diagnostic agreement between CA and VA was better at lower staining scores but improved after optimal cutoff based dichotomization.
Virchows Archiv, 2016
The incidence of head and neck squamous cell carcinomas is still growing, and the long-term progn... more The incidence of head and neck squamous cell carcinomas is still growing, and the long-term prognosis of advanced disease remains poor. Only a fraction of head and neck cancers are sensitive to the EGFR-inhibitor cetuximab, which is the only registered targeted therapy available today. In several cancers, gene copy number alterations of MET and PIK3CA have been found to be prognostic and predictive for therapy response. The aim of this study was to systematically analyze in head and neck cancers the pathological characteristics and prognostic significance of copy number changes of MET and PIK3CA genes. MET and PIK3CA copy numbers were analyzed by fluorescence in situ hybridization in tumor samples of 152 patients. Expression of EGFR, p16, and Ki67 was studied by immunohistochemistry. High polysomy of PIK3CA (chromosome 3) was found in 20 % of cases and amplification in 4.5 %. Regarding MET, 35 % of cases showed low or high polysomy of the gene (chromosome 7), while no intra-chromosomal amplification of MET was detected. PIK3CA copy number gain (high polysomy or amplification) was significantly associated with shorter diseasespecific survival, larger tumor volume, and lower p16 expression. MET copy number gain (low or high polysomy) in tumors was significantly associated with shorter disease-specific survival and lower level of EGFR. PIK3CA and MET may play an important role in oncogenesis of certain specific subtypes of head and neck cancer. There is an urgent need for the development of novel targeted therapies against these tumors associated with poor prognosis. Keywords MET. PIK3CA. CNG (copy number gain). Head and neck cancer (HNC)
Pancreatology
Introduction: Molecular pharmacological studies of the somatostatin analogue (TT-232 (Biostatin L... more Introduction: Molecular pharmacological studies of the somatostatin analogue (TT-232 (Biostatin Ltd.)/CAP-232 Caprion Pharmaceuticals Inc.) have revealed that the well-known tumour marker of pancreatic cancer, the M2 isotype of the key metabolic enzyme pyruvate kinase (M2PK) is also a potential molecular target of novel targeted therapies. Objectives: Determination of M2PK expression level of M2PK may be important in the personalized use of these drugs in the near future. Materials and Methods: We have determined the local expression of M2PK by qPCR assay and immunohystochemistry in surgical biopsies, and compared the results to the M2PK protein levels in the peripheral blood by ELISA based assay in the same patients and control individuals. Results: We found that peripheral blood M2PK protein level is a highly sensitive and specific tumour marker of pancreatic cancer but does not directly correlate with the local expression levels of M2PK. Distinction of different isoforms of PK in...
Conference Papers in Medicine, 2013
Background. Modulated electrohyperthermia (mEHT) is a noninvasive technique for targeted tumor tr... more Background. Modulated electrohyperthermia (mEHT) is a noninvasive technique for targeted tumor treatment. Method. HT29 human colorectal carcinoma cell line xenografted to both femoral regions of BalbC/nu/nu mice was treated with a single shot OTM treatment. Histomorphologic, immunohistochemical analysis TUNEL assay, and R&D Apoptosis array were performed on tissue samples. Results. mEHT caused a selective tumor demolition. An upregulation of TRAIL-R2 and FAS was observed. Cleaved caspase-3 positive cells appear at the tumor periphery. Cytochrome c and AIF release was observed in line with massive TUNEL positivity. Conclusion. In HT29 colorectal cancer xenograft, mEHT caused massive caspase independent cell death.
Anticancer research, 2009
The effect of gonadotropin-releasing hormone (GnRH) analogs on prostate carcinoma is partly a res... more The effect of gonadotropin-releasing hormone (GnRH) analogs on prostate carcinoma is partly a result of breaking the pituitary-gonadal axis, and partly the direct action on tumor cells expressing the GnRH receptor (GnRHR). The aim of this study was to detect the extent of correlation between the expression of GnRHR and also the androgen receptor (AR) and the efficacy of total androgen blockade (TAB). Needle biopsy samples of twenty advanced prostate carcinoma patients were investigated histologically regarding Gleason score, AR and GnRHR status of the tumor cells. An affinity purified polyclonal antibody reacting with GnRHR and a monoclonal antibody for AR were applied for immunoperoxidase reactions. TAB was started in each case. Pathological, radiological and laboratory-prostate-specific antigen (PSA) data obtained before the start of TAB and survival, PSA values, and radiological findings after three years of TAB were related to AR and GnRHR. Regarding the clinical, radiological a...