Gene Siegal - Academia.edu (original) (raw)

Papers by Gene Siegal

Cancer Biotherapy Radiopharmaceuticals, 2006

any CRAd for clinical trials in dogs, we sought to examine the effects and safety of administrati... more any CRAd for clinical trials in dogs, we sought to examine the effects and safety of administration of OStargeted CAV2 CRAd in normal dogs. Short-term physiologic indicators of stress and shock, as well as gross and histological changes in a variety of tissues, were examined, and no major signs of virus-associated toxicity were noted. In addition, short-term immunosuppression did not increase CRAd toxicity. This study marks the first administration of a CRAd in an outbred large animal model and is an important milestone in the application of this modality in human patients.

Transplantation, 1998

ABSTRACT Skin graft rejection and humoral alloantibody response (hemag-glutinins and cytotoxins) ... more ABSTRACT Skin graft rejection and humoral alloantibody response (hemag-glutinins and cytotoxins) were observed in hyperimmunized mice (A/He to CBA strain combinations). Intact spleen cells or cell-free splenic preparations were used as immunizing agents. The initial use of adjuvant followed by 6 weekly i.v., i.p., or s.c. injections without adjuvant resulted in a slight but significant prolongation of the challenging skin graft survival in the presence of high antibody levels at the time of graft challenge. However, survival of the second challenging grafts in the same hyperimmunized recipients was much shorter, indicating that once the hyperimmunized recipients rejected the first challenging grafts, they became sensitized. Passive immunizations with a pooled immune serum or abdominal fluid resulted in a very slight prolongation, rather than accelerated rejection, of the challenging grafts. The possible roles of humoral antibodies in accelerated rejection (allograft sensitivity) and prolongation of graft survival (enhancement) are discussed.

Cancer Investigation, Feb 1, 1996

Because most cancer deaths result from disseminated disease, understanding the regulation of tumo... more Because most cancer deaths result from disseminated disease, understanding the regulation of tumor invasion and metastasis is a central theme in tumor cell biology. Interactions between extracellular matrices (ECM) and cellular microenvironment play a crucial role in this process. We have tested selected amino acids and polyamines for their ability to regulate RL95-2 cell invasion through both intact human amniotic basement membrane and a novel human ECM (Amgel). Three major systems for neutral amino acid transport, systems L, A, and ASC, are operational in these neoplastic cells. Amino acids entering the cell via transport system A or N, i.e., (methyl amino)-isobutyrate (MeAIB) or Asn, markedly enhanced invasiveness of these human adenocarcinoma cells as measured by a standard 72-hr amnion or Amgel invasion assay. Addition of 2-amino-2-norborane carboxylic acid (BCH; 1 mM), a model substrate of the L transport system, caused a significant decrease in invasive activity when tested in the Amgel assay. Interestingly, Val lowers steady-state levels of MeAIB uptake and blocks the increase in cell invasion elicited by MeAIB. At the same time, these amino acids do not influence cell proliferation activity. Neither the charged amino acid Lys or Asp (not transported by A/N/L systems) nor the polyamines putrescine, spermidine, or spermine modulate invasiveness under similar experimental conditions. Moreover, the observed time-dependent stimulation of system A activity (cellular influx of MeAIB) by substrate depletion is prevented by the addition of actinomycin D (5 microM) or cycloheximide (100 microM), suggesting the involvement of de novo RNA and protein synthesis events in these processes. MeAIB treatment of tumor cells selectively increased the activities of key invasion-associated type IV collagenases/gelatinases. These results indicate that in the absence of defined regulators (growth factors or hormones), certain amino acids may contribute to the epigenetic control of human tumor cell invasion and, by extension, metastasis. We propose that amino acids, acting via specific signaling pathways, modulate phenotypic cell behavior by modulating the levels of key regulatory enzymatic proteins.

Cancer Research, Apr 15, 1997

Skeletal Radiology, Feb 1, 2007

American Journal of Clinical Pathology, 2009

American Journal of Respiratory and Critical Care Medicine, Dec 20, 2012

Rationale: Mitochondria have important roles in intracellular energy generation, modulation of ap... more Rationale: Mitochondria have important roles in intracellular energy generation, modulation of apoptosis, and redox-dependent intracellular signaling. Although reactive oxygen species (ROS) participate in the regulation of intracellular signaling pathways, including activation of nuclear factor (NF)-kB, there is only limited information concerning the role of mitochondrially derived ROS in modulating cellular activation and tissue injury associated with acute inflammatory processes. Objectives: To examine involvement of the mitochondrial electron transport chain complex I on LPS-mediated NF-kB activation in neutrophils and neutrophil-dependent acute lung injury. Methods: Neutrophils incubated with rotenone or metformin were treated with bacterial lipopolysaccharide (LPS) to determine the effects of mitochondrial complex I inhibition on intracellular concentrations of reactive oxygen species, NF-kB activation, and proinflammatory cytokine expression. Acute lung injury was produced by intratracheal injection of LPS into control, metformin, or rotenonetreated mice. Measurements and Main Results: Inhibition of complex I with either rotenone or the antihyperglycemic agent metformin was associated with increased intracellular levels of both superoxide and hydrogen peroxide, as well as inhibition of LPS-induced IkB-a degradation, NF-kB nuclear accumulation, and proinflammatory cytokine production. Treatment of LPS-exposed mice with rotenone or metformin resulted in inhibition of complex I in the lungs, as well as diminished severity of lung injury. Conclusions: These results demonstrate that mitochondrial complex I plays an important role in modulating Toll-like receptor 4-mediated neutrophil activation and suggest that metformin, as well as other agents that inhibit mitochondrial complex I, may be useful in the prevention or treatment of acute inflammatory processes in which activated neutrophils play a major role, such as acute lung injury.

Clinical and Experimental Metastasis, Jun 1, 1996

Cell adhesion to and migration through extracellular matrices (ECM) are critical events in tumor ... more Cell adhesion to and migration through extracellular matrices (ECM) are critical events in tumor invasion and metastasis. Previous work by us had demonstrated that signaling of epidermal growth factor receptor (EGFR) confers an oncogenic phenotype on NR6 cells and that these cells when transfected with holo EGFR demonstrate greater motility and invasiveness than cells carrying a carboxy-terminal truncated EGFR. Recently, a cell surface glycoprotein, CD44, has been implicated in celI-ECM adhesion involved in tumor cell migration, signal transduction, and metastasis. We investigated whether EGF regulates cellular interactions with ECM components, and in particular, hyaluronate, by modulating CD44 expression. In vitro cell attachment assays on hyaluronate-coated plates demonstrated similar basal level of binding (.-.33%) for murine NR6 parental cells devoid of endogenous EGFR (P) or expressing wild-type EGFR (WT), while a time-dependent increase in binding was observed in WT cells stimulated with EGF. Additionally, utilizing monoclonal antibody blocking assays, CD44, but not EGFR, was shown to be directly involved in this attachment. Both WT and P cells possessed equivalent 95 kDa bands on immunobiots, corresponding to CD44. The existence of CD44 mRNA was verified by RT-PCR using synthetic oligonucleotides in which a 1.1 kb cDNA was detected in both cell lines and confirmed by DNA sequencing. After 24-h exposure to exogenous EGF, an increase in CD44 protein and mRNA expression was found in WT ceils, but not in P cells, supporting the contention that a functional EGFR signaling pathway is required for CD44 regulation. Thus, EGF stimulates cell binding to hyaluronate in vitro by regulating CD44 expression.

Osteosarcoma is the most common primary tumor of bone, yet its absolute incidence among malignant... more Osteosarcoma is the most common primary tumor of bone, yet its absolute incidence among malignant tumors is low. Within its strict histologic definition, osteosarcoma comprises a family of lesions with considerable diversity in histologic features and grade. Its prognosis is dependent not only on these parameters but also on its anatomic site. It may occur inside the bones (in the intramedullary or intracortical compartment), on the surfaces of bones, and in extraosseous sites. Information of diagnostic or prognostic significance has not been elucidated from studies of its cytogenetics. This review summarizes the anatomic and histologic variations of osteosarcoma and offers a schema for its subclassification.

Human Pathology, Oct 1, 2004

The diagnosis of a bone tumor is often an arduous task, even for the most experienced orthopedic ... more The diagnosis of a bone tumor is often an arduous task, even for the most experienced orthopedic pathologist. As a starting point, the classification of bone tumors is based on a histogenetic perspective encompassing the type of matrix produced (or not produced) by the tumor. In general, the surgical pathology report should include data pertinent to the treatment and prognostication of an individual patient, and the report should be delivered to the clinician in a clear, concise fashion. Reporting of most bone tumors is similar and includes such information as the type of surgery done, anatomic site, histological type and grade of the tumor (if applicable), and the adequacy of surgical margins. Special emphasis is needed for those tumors with distinct and well-established prognostic and therapeutic features such as osteosarcoma and Ewing's sarcoma/peripheral neuroectodermal tumor. Our recommendation emphasizes a standardized protocol for these sarcomas, especially in light of evidence that postchemotherapeutic tumor necrosis is of prognostic significance. It is also important to note that radiographic imaging plays a very important, often critical, role in allowing the pathologist the opportunity to reach the best final diagnosis. This is especially true when a malignant interpretation is contemplated and in subtyping lesions. We recommend close collaboration between musculoskeletal radiologists, clinicians, and pathologists when dealing with complicated neoplasms of bone.

Updates in diagnostic pathology CHHIENG David C.

Cancer Research, Apr 15, 2006

Human Pathlogy, 2004

Sarcomas infrequently develop in osseous sites of fibrous dysplasia. We report a patient with Maz... more Sarcomas infrequently develop in osseous sites of fibrous dysplasia. We report a patient with Mazabraud's syndrome (polyostotic fibrous dysplasia and soft tissue myxomas) complicated by the development of osteogenic sarcoma in a bone affected by fibrous dysplasia. This is the third case of osteosarcoma within the small population of reported patients with Mazabraud's syndrome. There may be an increased incidence of malignant transformation in these individuals' dysplastic bones above that associated with patients suffering from fibrous dysplasia alone.

Cancer Research, Apr 15, 2006

International Journal of Oncology, Jul 1, 2005

Conditionally replicating adenoviruses (CRAds) represent a promising new modality for the treatme... more Conditionally replicating adenoviruses (CRAds) represent a promising new modality for the treatment of cancer. A key contribution in this regard was the introduction of tumor-selective viral replication for amplification of the initial inoculum. Specifically, following cellular infection, the virus replicates selectively in the infected tumor cells and kills the cells by cytolysis. Next, the progeny virions infect surrounding target cells, replicate and eradicate the infected tumor cells, leaving normal cells unaffected. However, to date there have been two limitations to clinical application of these CRAd agents; i.e., both infectivity and tumor specificity are poor. Survivin protein is a novel member of the inhibitor of apoptosis (IAP) protein family, which plays an important role in the survival of cancer cells and progression of malignancies. Previous data have shown the survivin promoter has high activities in multiple cancer cells with a low activity in mouse liver. In this study, we propose an improved CRAd agent to circumvent the obstacles. We constructed a novel CRAd agent, CRAd-Survivin-RGD, which contains both the survivin promoter (either the short version, S-S, or the long version, S-L) to selectively drive E1 gene expression in tumor cells and a capsid modification and RGD4C to specifically enhance the tumor infectivity of CRAd agents. Both CRAd agents (S-S and S-L) showed high replication rates in the breast cancer cell line, MDA-MB-361, and low promoter activity in both normal mouse and human liver, thus signifying the CRAd agents have the phenotype of 'tumor on/liver off'. In cytocidal experiments, the CRAd agents demonstrated a high cytocidal effect on multiple cancer cell lines, including the breast cancer cell line, MDA-MB-231; the glioma cell line, D65, the melanoma cell line, MEL-28; and mesothelioma, Meso2374. The results also showed the tumor growth was dramatically inhibited by intertumoral administration of the CRAd agents in a breast cancer (MDA-MB-361) xenograft animal model. These data clearly demonstrate that CRAd-Survivin-RGD is a potential novel therapeutic agent for treatment in many, but not all, human cancers.

Clinical Cancer Research, Nov 1, 2000

To that end, we previously have shown the potential of CD34 ؉ endothelial progenitors for systemi... more To that end, we previously have shown the potential of CD34 ؉ endothelial progenitors for systemic gene delivery in a primate angiogenesis model. Here we seek to explore the utility of CD34 ؉ cells of human origin as vehicles for toxin genes and, in particular, to measure their capacity to effect a cytotoxic bystander effect in human endothelium and tumor cells. To this end, CD34 ؉ cells were transduced with TOZ.1, a nonreplicative herpes simplex vector encoding thymidine kinase. To test the capacity of CD34 ؉ cells to induce a cytotoxic bystander effect in target cells, we performed mixing experiments, whereby TOZ.1-transduced CD34 ؉ cells were mixed with either human vascular endothelial cells or human ovarian tumor cells (SKOV3.ip1). Cell viability was measured by the MTS assay. Lastly, mixtures of TOZ.1-transduced CD34 ؉ cells and SKOV3.ip1 tumor cells were injected s.c. to evaluate the bystander effect in vivo. After transduction of CD34 ؉ cells with TOZ.1, treatment with ganciclovir induced the killing of 99% of cells. In cell-mixing experiments, a linear correlation was observed between the percentages of TOZ.1transduced CD34 ؉ cells and total cell killing. For example, when 50% of CD34 ؉ transduced cells were mixed with nontransduced SKOV3.ip1, >70% of all cells died. Similarly, when the same percentage was mixed with human vascular endothelial cells, >80% of the total number of cells died. In vivo studies showed an abrogation of tumor forma-tion when TOZ.1-transduced CD34 ؉ cells and ganciclovir were administered. Our observations establish the feasibility of a method for cell-based toxin gene delivery into disseminated areas of tumor angiogenesis.

Clin Exp Metastas, 1988

Tumor cell invasion of basement membranes is required at several steps in the process of metastas... more Tumor cell invasion of basement membranes is required at several steps in the process of metastasis. To study the genetic and biochemical events mediating invasion, a variant cell line (TK) was selected from the metastatic M2 K1735 murine melanoma cell line. A novel selection procedure was used, based on in vitro and in vivo invasion and growth upon basement membrane and stroma. Additionally, two extrapulmonary metastases of the TK cell line, TK-Eve and TK-Liver, were established as cell lines and characterized. The TK cell line demonstrates greater metastatic potential in vivo and invasive ability in vitro than the parent M2 cell line, confirming the validity of the selection procedure. In addition, the M2 and TK cell lines were examined for other cell functions involved in the metastatic process. Cellular growth rates and sensitivity to T lymphocyte and natural killer cell lysis were not determining factors in the metastatic potentials of the M2 and selected cell lines; possible macrophage contribution to metastatic behavior was noted. [3s S]methionine pulse labeling of protein synthesis and karyotypic analysis confirm the close relationship of parental and selected cell lines.

Cancer Research, Sep 1, 2001

Angiolipomas are among the most common benign soft-tissue tumors and usually present as solitary ... more Angiolipomas are among the most common benign soft-tissue tumors and usually present as solitary nodules; however, angiolipomas also may present as multiple subcutaneous nodules, typically on the arms and trunk of young men. Although multiple angiolipomas most often occur sporadically, a family history can be identified in a minority of cases. Familial angiolipomatosis is a rare condition with an autosomal-recessive transmission pattern that is characterized by multiple subcutaneous tumors and a family history of similar lesions, which are not associated with malignant neoplasms. We report a case of familial angiolipomatosis with an unusual autosomal-dominant transmission pattern. Our patient presented with multiple angiolipomas that were highly suggestive of familial angiolipomatosis transmitted in an autosomal-dominant fashion, as he had several family members with a history of similar fatty tumors. Autosomal-dominant familial angiolipomatosis may be misdiagnosed as neurofibromatosis type I. Therefore, in cases of multiple subcutaneous tumors and a family history of similar lesions, histologic examination is important to establish the correct diagnosis.

... to share examples of rare cases with us. Special thanks go to Trena Held, whose diligence and... more ... to share examples of rare cases with us. Special thanks go to Trena Held, whose diligence and persistence made the preparation of this work possible. Page 14. Page 15. CONTENTS 1. Introduction, 3 Comparison of FNA to ...

Cancer Biotherapy Radiopharmaceuticals, 2006

any CRAd for clinical trials in dogs, we sought to examine the effects and safety of administrati... more any CRAd for clinical trials in dogs, we sought to examine the effects and safety of administration of OStargeted CAV2 CRAd in normal dogs. Short-term physiologic indicators of stress and shock, as well as gross and histological changes in a variety of tissues, were examined, and no major signs of virus-associated toxicity were noted. In addition, short-term immunosuppression did not increase CRAd toxicity. This study marks the first administration of a CRAd in an outbred large animal model and is an important milestone in the application of this modality in human patients.

Transplantation, 1998

ABSTRACT Skin graft rejection and humoral alloantibody response (hemag-glutinins and cytotoxins) ... more ABSTRACT Skin graft rejection and humoral alloantibody response (hemag-glutinins and cytotoxins) were observed in hyperimmunized mice (A/He to CBA strain combinations). Intact spleen cells or cell-free splenic preparations were used as immunizing agents. The initial use of adjuvant followed by 6 weekly i.v., i.p., or s.c. injections without adjuvant resulted in a slight but significant prolongation of the challenging skin graft survival in the presence of high antibody levels at the time of graft challenge. However, survival of the second challenging grafts in the same hyperimmunized recipients was much shorter, indicating that once the hyperimmunized recipients rejected the first challenging grafts, they became sensitized. Passive immunizations with a pooled immune serum or abdominal fluid resulted in a very slight prolongation, rather than accelerated rejection, of the challenging grafts. The possible roles of humoral antibodies in accelerated rejection (allograft sensitivity) and prolongation of graft survival (enhancement) are discussed.

Cancer Investigation, Feb 1, 1996

Because most cancer deaths result from disseminated disease, understanding the regulation of tumo... more Because most cancer deaths result from disseminated disease, understanding the regulation of tumor invasion and metastasis is a central theme in tumor cell biology. Interactions between extracellular matrices (ECM) and cellular microenvironment play a crucial role in this process. We have tested selected amino acids and polyamines for their ability to regulate RL95-2 cell invasion through both intact human amniotic basement membrane and a novel human ECM (Amgel). Three major systems for neutral amino acid transport, systems L, A, and ASC, are operational in these neoplastic cells. Amino acids entering the cell via transport system A or N, i.e., (methyl amino)-isobutyrate (MeAIB) or Asn, markedly enhanced invasiveness of these human adenocarcinoma cells as measured by a standard 72-hr amnion or Amgel invasion assay. Addition of 2-amino-2-norborane carboxylic acid (BCH; 1 mM), a model substrate of the L transport system, caused a significant decrease in invasive activity when tested in the Amgel assay. Interestingly, Val lowers steady-state levels of MeAIB uptake and blocks the increase in cell invasion elicited by MeAIB. At the same time, these amino acids do not influence cell proliferation activity. Neither the charged amino acid Lys or Asp (not transported by A/N/L systems) nor the polyamines putrescine, spermidine, or spermine modulate invasiveness under similar experimental conditions. Moreover, the observed time-dependent stimulation of system A activity (cellular influx of MeAIB) by substrate depletion is prevented by the addition of actinomycin D (5 microM) or cycloheximide (100 microM), suggesting the involvement of de novo RNA and protein synthesis events in these processes. MeAIB treatment of tumor cells selectively increased the activities of key invasion-associated type IV collagenases/gelatinases. These results indicate that in the absence of defined regulators (growth factors or hormones), certain amino acids may contribute to the epigenetic control of human tumor cell invasion and, by extension, metastasis. We propose that amino acids, acting via specific signaling pathways, modulate phenotypic cell behavior by modulating the levels of key regulatory enzymatic proteins.

Cancer Research, Apr 15, 1997

Skeletal Radiology, Feb 1, 2007

American Journal of Clinical Pathology, 2009

American Journal of Respiratory and Critical Care Medicine, Dec 20, 2012

Rationale: Mitochondria have important roles in intracellular energy generation, modulation of ap... more Rationale: Mitochondria have important roles in intracellular energy generation, modulation of apoptosis, and redox-dependent intracellular signaling. Although reactive oxygen species (ROS) participate in the regulation of intracellular signaling pathways, including activation of nuclear factor (NF)-kB, there is only limited information concerning the role of mitochondrially derived ROS in modulating cellular activation and tissue injury associated with acute inflammatory processes. Objectives: To examine involvement of the mitochondrial electron transport chain complex I on LPS-mediated NF-kB activation in neutrophils and neutrophil-dependent acute lung injury. Methods: Neutrophils incubated with rotenone or metformin were treated with bacterial lipopolysaccharide (LPS) to determine the effects of mitochondrial complex I inhibition on intracellular concentrations of reactive oxygen species, NF-kB activation, and proinflammatory cytokine expression. Acute lung injury was produced by intratracheal injection of LPS into control, metformin, or rotenonetreated mice. Measurements and Main Results: Inhibition of complex I with either rotenone or the antihyperglycemic agent metformin was associated with increased intracellular levels of both superoxide and hydrogen peroxide, as well as inhibition of LPS-induced IkB-a degradation, NF-kB nuclear accumulation, and proinflammatory cytokine production. Treatment of LPS-exposed mice with rotenone or metformin resulted in inhibition of complex I in the lungs, as well as diminished severity of lung injury. Conclusions: These results demonstrate that mitochondrial complex I plays an important role in modulating Toll-like receptor 4-mediated neutrophil activation and suggest that metformin, as well as other agents that inhibit mitochondrial complex I, may be useful in the prevention or treatment of acute inflammatory processes in which activated neutrophils play a major role, such as acute lung injury.

Clinical and Experimental Metastasis, Jun 1, 1996

Cell adhesion to and migration through extracellular matrices (ECM) are critical events in tumor ... more Cell adhesion to and migration through extracellular matrices (ECM) are critical events in tumor invasion and metastasis. Previous work by us had demonstrated that signaling of epidermal growth factor receptor (EGFR) confers an oncogenic phenotype on NR6 cells and that these cells when transfected with holo EGFR demonstrate greater motility and invasiveness than cells carrying a carboxy-terminal truncated EGFR. Recently, a cell surface glycoprotein, CD44, has been implicated in celI-ECM adhesion involved in tumor cell migration, signal transduction, and metastasis. We investigated whether EGF regulates cellular interactions with ECM components, and in particular, hyaluronate, by modulating CD44 expression. In vitro cell attachment assays on hyaluronate-coated plates demonstrated similar basal level of binding (.-.33%) for murine NR6 parental cells devoid of endogenous EGFR (P) or expressing wild-type EGFR (WT), while a time-dependent increase in binding was observed in WT cells stimulated with EGF. Additionally, utilizing monoclonal antibody blocking assays, CD44, but not EGFR, was shown to be directly involved in this attachment. Both WT and P cells possessed equivalent 95 kDa bands on immunobiots, corresponding to CD44. The existence of CD44 mRNA was verified by RT-PCR using synthetic oligonucleotides in which a 1.1 kb cDNA was detected in both cell lines and confirmed by DNA sequencing. After 24-h exposure to exogenous EGF, an increase in CD44 protein and mRNA expression was found in WT ceils, but not in P cells, supporting the contention that a functional EGFR signaling pathway is required for CD44 regulation. Thus, EGF stimulates cell binding to hyaluronate in vitro by regulating CD44 expression.

Osteosarcoma is the most common primary tumor of bone, yet its absolute incidence among malignant... more Osteosarcoma is the most common primary tumor of bone, yet its absolute incidence among malignant tumors is low. Within its strict histologic definition, osteosarcoma comprises a family of lesions with considerable diversity in histologic features and grade. Its prognosis is dependent not only on these parameters but also on its anatomic site. It may occur inside the bones (in the intramedullary or intracortical compartment), on the surfaces of bones, and in extraosseous sites. Information of diagnostic or prognostic significance has not been elucidated from studies of its cytogenetics. This review summarizes the anatomic and histologic variations of osteosarcoma and offers a schema for its subclassification.

Human Pathology, Oct 1, 2004

The diagnosis of a bone tumor is often an arduous task, even for the most experienced orthopedic ... more The diagnosis of a bone tumor is often an arduous task, even for the most experienced orthopedic pathologist. As a starting point, the classification of bone tumors is based on a histogenetic perspective encompassing the type of matrix produced (or not produced) by the tumor. In general, the surgical pathology report should include data pertinent to the treatment and prognostication of an individual patient, and the report should be delivered to the clinician in a clear, concise fashion. Reporting of most bone tumors is similar and includes such information as the type of surgery done, anatomic site, histological type and grade of the tumor (if applicable), and the adequacy of surgical margins. Special emphasis is needed for those tumors with distinct and well-established prognostic and therapeutic features such as osteosarcoma and Ewing's sarcoma/peripheral neuroectodermal tumor. Our recommendation emphasizes a standardized protocol for these sarcomas, especially in light of evidence that postchemotherapeutic tumor necrosis is of prognostic significance. It is also important to note that radiographic imaging plays a very important, often critical, role in allowing the pathologist the opportunity to reach the best final diagnosis. This is especially true when a malignant interpretation is contemplated and in subtyping lesions. We recommend close collaboration between musculoskeletal radiologists, clinicians, and pathologists when dealing with complicated neoplasms of bone.

Updates in diagnostic pathology CHHIENG David C.

Cancer Research, Apr 15, 2006

Human Pathlogy, 2004

Sarcomas infrequently develop in osseous sites of fibrous dysplasia. We report a patient with Maz... more Sarcomas infrequently develop in osseous sites of fibrous dysplasia. We report a patient with Mazabraud's syndrome (polyostotic fibrous dysplasia and soft tissue myxomas) complicated by the development of osteogenic sarcoma in a bone affected by fibrous dysplasia. This is the third case of osteosarcoma within the small population of reported patients with Mazabraud's syndrome. There may be an increased incidence of malignant transformation in these individuals' dysplastic bones above that associated with patients suffering from fibrous dysplasia alone.

Cancer Research, Apr 15, 2006

International Journal of Oncology, Jul 1, 2005

Conditionally replicating adenoviruses (CRAds) represent a promising new modality for the treatme... more Conditionally replicating adenoviruses (CRAds) represent a promising new modality for the treatment of cancer. A key contribution in this regard was the introduction of tumor-selective viral replication for amplification of the initial inoculum. Specifically, following cellular infection, the virus replicates selectively in the infected tumor cells and kills the cells by cytolysis. Next, the progeny virions infect surrounding target cells, replicate and eradicate the infected tumor cells, leaving normal cells unaffected. However, to date there have been two limitations to clinical application of these CRAd agents; i.e., both infectivity and tumor specificity are poor. Survivin protein is a novel member of the inhibitor of apoptosis (IAP) protein family, which plays an important role in the survival of cancer cells and progression of malignancies. Previous data have shown the survivin promoter has high activities in multiple cancer cells with a low activity in mouse liver. In this study, we propose an improved CRAd agent to circumvent the obstacles. We constructed a novel CRAd agent, CRAd-Survivin-RGD, which contains both the survivin promoter (either the short version, S-S, or the long version, S-L) to selectively drive E1 gene expression in tumor cells and a capsid modification and RGD4C to specifically enhance the tumor infectivity of CRAd agents. Both CRAd agents (S-S and S-L) showed high replication rates in the breast cancer cell line, MDA-MB-361, and low promoter activity in both normal mouse and human liver, thus signifying the CRAd agents have the phenotype of 'tumor on/liver off'. In cytocidal experiments, the CRAd agents demonstrated a high cytocidal effect on multiple cancer cell lines, including the breast cancer cell line, MDA-MB-231; the glioma cell line, D65, the melanoma cell line, MEL-28; and mesothelioma, Meso2374. The results also showed the tumor growth was dramatically inhibited by intertumoral administration of the CRAd agents in a breast cancer (MDA-MB-361) xenograft animal model. These data clearly demonstrate that CRAd-Survivin-RGD is a potential novel therapeutic agent for treatment in many, but not all, human cancers.

Clinical Cancer Research, Nov 1, 2000

To that end, we previously have shown the potential of CD34 ؉ endothelial progenitors for systemi... more To that end, we previously have shown the potential of CD34 ؉ endothelial progenitors for systemic gene delivery in a primate angiogenesis model. Here we seek to explore the utility of CD34 ؉ cells of human origin as vehicles for toxin genes and, in particular, to measure their capacity to effect a cytotoxic bystander effect in human endothelium and tumor cells. To this end, CD34 ؉ cells were transduced with TOZ.1, a nonreplicative herpes simplex vector encoding thymidine kinase. To test the capacity of CD34 ؉ cells to induce a cytotoxic bystander effect in target cells, we performed mixing experiments, whereby TOZ.1-transduced CD34 ؉ cells were mixed with either human vascular endothelial cells or human ovarian tumor cells (SKOV3.ip1). Cell viability was measured by the MTS assay. Lastly, mixtures of TOZ.1-transduced CD34 ؉ cells and SKOV3.ip1 tumor cells were injected s.c. to evaluate the bystander effect in vivo. After transduction of CD34 ؉ cells with TOZ.1, treatment with ganciclovir induced the killing of 99% of cells. In cell-mixing experiments, a linear correlation was observed between the percentages of TOZ.1transduced CD34 ؉ cells and total cell killing. For example, when 50% of CD34 ؉ transduced cells were mixed with nontransduced SKOV3.ip1, >70% of all cells died. Similarly, when the same percentage was mixed with human vascular endothelial cells, >80% of the total number of cells died. In vivo studies showed an abrogation of tumor forma-tion when TOZ.1-transduced CD34 ؉ cells and ganciclovir were administered. Our observations establish the feasibility of a method for cell-based toxin gene delivery into disseminated areas of tumor angiogenesis.

Clin Exp Metastas, 1988

Tumor cell invasion of basement membranes is required at several steps in the process of metastas... more Tumor cell invasion of basement membranes is required at several steps in the process of metastasis. To study the genetic and biochemical events mediating invasion, a variant cell line (TK) was selected from the metastatic M2 K1735 murine melanoma cell line. A novel selection procedure was used, based on in vitro and in vivo invasion and growth upon basement membrane and stroma. Additionally, two extrapulmonary metastases of the TK cell line, TK-Eve and TK-Liver, were established as cell lines and characterized. The TK cell line demonstrates greater metastatic potential in vivo and invasive ability in vitro than the parent M2 cell line, confirming the validity of the selection procedure. In addition, the M2 and TK cell lines were examined for other cell functions involved in the metastatic process. Cellular growth rates and sensitivity to T lymphocyte and natural killer cell lysis were not determining factors in the metastatic potentials of the M2 and selected cell lines; possible macrophage contribution to metastatic behavior was noted. [3s S]methionine pulse labeling of protein synthesis and karyotypic analysis confirm the close relationship of parental and selected cell lines.

Cancer Research, Sep 1, 2001

Angiolipomas are among the most common benign soft-tissue tumors and usually present as solitary ... more Angiolipomas are among the most common benign soft-tissue tumors and usually present as solitary nodules; however, angiolipomas also may present as multiple subcutaneous nodules, typically on the arms and trunk of young men. Although multiple angiolipomas most often occur sporadically, a family history can be identified in a minority of cases. Familial angiolipomatosis is a rare condition with an autosomal-recessive transmission pattern that is characterized by multiple subcutaneous tumors and a family history of similar lesions, which are not associated with malignant neoplasms. We report a case of familial angiolipomatosis with an unusual autosomal-dominant transmission pattern. Our patient presented with multiple angiolipomas that were highly suggestive of familial angiolipomatosis transmitted in an autosomal-dominant fashion, as he had several family members with a history of similar fatty tumors. Autosomal-dominant familial angiolipomatosis may be misdiagnosed as neurofibromatosis type I. Therefore, in cases of multiple subcutaneous tumors and a family history of similar lesions, histologic examination is important to establish the correct diagnosis.

... to share examples of rare cases with us. Special thanks go to Trena Held, whose diligence and... more ... to share examples of rare cases with us. Special thanks go to Trena Held, whose diligence and persistence made the preparation of this work possible. Page 14. Page 15. CONTENTS 1. Introduction, 3 Comparison of FNA to ...