Biomedical subjects

Mohammad Ghazizadeh

Publications and source records attributed to Mohammad Ghazizadeh.

At least 19 recordsLinked to original sources

PubMed2006

Functional implications of the IL-6 signaling pathway in keloid pathogenesis.

The molecular mechanism(s) behind keloid pathogenesis remains unclear. Previously by global gene expression analysis of keloid fibroblasts (KFs), we implicated the IL-6 signaling pathway in keloid pathogenesis. Here, we determine a functional role of IL-6 signaling in keloid scars. Primary cultures of KFs and surrounding nonlesional fibroblasts (NFs) were subjected to induction or inhibition of IL-6 or its specific receptor IL-6 receptor alpha (IL-6R alpha) and detection of their effects on extracellular matrix gene expression. The levels of gp130 and several downstream targets in IL-6 signaling were also examined. IL-6 secretion was significantly higher in KFs than NFs. Addition of IL-6 peptide to NFs culture or inhibition of IL-6 or its receptor IL-6R alpha by their corresponding antibodies in KFs culture revealed a dose-dependent increase or decrease in collagen type I alpha 2 and fibronectin 1 mRNAs, respectively. Induction of IL-6 by IL-1beta peptide and stimulation by IL-6 peptide in NFs, or inhibition of IL-6 or IL-6R alpha in KFs cultures demonstrated a dose-dependent increase or decrease in procollagen I synthesis, respectively. The mRNA and protein expressions of gp130 and several downstream targets in IL-6 signaling (JAK1, STAT3, RAF1, and ELK1) were upregulated in KFs versus NFs. Our results indicate that IL-6 signaling may play an integral role in keloid pathogenesis and provide clues for development of IL-6 receptor blocking strategies for therapy or prophylaxis of keloid scars.

Adult↗

PubMed2006

Potential role of the Slit/Robo signal pathway in angiogenesis.

Intensive investigations on angiogenesis and vasculogenesis have increased our understanding of molecular mechanisms of blood vessel formation during pathologic and developmental conditions. However, endothelial cells (ECs), the main component of vasculature, are heterogeneous, as revealed by our phenotypic and molecular biological studies in the laboratory, and it is still hard to adequately understand the molecular mechanisms of angiogenesis and vasculogenesis. Indeed, there are several major ligand/receptor signal pathways: VEGF/VEGFR, Jagged-1/Notch, Wnt ligand/frizzled receptor, and ephrin/Eph; each of which having distinct and independent roles during vascular formation. In this review, we focus on the angiogenic effect of the Slit and Robo signal pathway that was formally known as neuronal axon guidance. Among the existing vascular signals, this pathway is the most recently found ligand/receptor vascular signal, and may play important physiological roles as other major receptor/ligand signals do. Here, we briefly address: (1) the background of Slit and Robo families; (2) expression patterns of Slit and Robo; (3) functional roles of the Slit/Robo pathway in vascular formation; and (4) confronting tasks of this novel vascular pathway in the near future. Together, a summary of these data suggest the essential role of the Slit/Robo pathway in angiogenesis, and may explain why multiple vascular signals exist in heterogenic endothelial cells.

Angiogenesis Inhibitors↗

PubMed2006

Critical roles of capillary endothelial cells for alveolar remodeling in nonspecific and usual interstitial pneumonias.

To characterize the relationship between angiogenesis factors and alveolar remodeling in interstitial lung diseases, we examined alveolar capillary endothelial cells in the normal lung (n=5) and in lungs with nonspecific interstitial pneumonia (NSIP) (n=4) or usual interstitial pneumonia (UIP) (n=6) using immunofluorescence staining for thrombmodulin and von Willebrand factor (vWF). With three-dimensional images of alveolar capillaries, the diameter of capillary tubes and their branching frequency per unit length were determined to define rearrangement of the capillary meshwork. Alveolar capillary endothelial cells in normal lungs expressed surface thrombomodulin, and those in lungs with cellular NSIP often showed coexpression of surface thrombmodulin and cytoplasmic vWF. In the alveolar septa of fibrotic NSIP and UIP, capillary endothelial cells demonstrated vWF in only the cytoplasm. Capillary branching frequencies in NSIP and UIP were decreased to 45% and 22%, respectively, of the normal level (p<0.002). Compared with normal lungs, in NSIP and UIP lungs alveolar capillaries containing TUNEL-positive endothelial cells (p<0.05) showed increases of 3.6-fold and 4.3-fold, respectively, indicating a close correlation between endothelial cell apoptosis and remodeling of alveolar capillary frameworks. The analysis of mRNA expression of vascular endothelial growth factors (VEGF) and their receptors (VEGFR1 and VEGFR2) showed a significant decrease in each VEGF isoform and in VEGFR2 mRNA in representative alveolar wall tissues microdissected from the normal, NSIP, and UIP lungs. These results suggest that decreased expression of VEGF mRNA is associated with a reduction in the number of capillary tubes via endothelial cell apoptosis that possibly results in alveolar remodeling in NSIP and UIP. However, whether VEGF is related to fibroblastic activation in the interstitial matrix remains unclear.

Antigens↗

PubMed2005

Characterization of the degradation of recombinant rat urate oxidase in tetracycline controlled gene expression cells.

Our previous study has shown that uric acid is metabolized by recombinant rat urate oxidase (UOX) and generates hydrogen peroxide leading to DNA damage and cell transformation. However, in transformed cells protein levels of UOX were reduced compared with the control cell. To investigate the characterization and the mechanisms responsible for the degradation of UOX, a controllable gene expression system has been used to switch on/off controlled expression of rat UOX in vitro. Chinese hamster ovary cells were double transfected with regulatory and responsive plasmids, pCMV-tTA and pTRE-rUOX, respectively. The cells expressing rat UOX were subtly controlled by tetracycline (Tc). High levels of UOX mRNA and protein enzymatic activity were observed when the cells were cultured in the absence of Tc. The functional recombinant rat UOX was present in the form of crystalloid cores structures that localized within the peroxisomes of the cells, which was confirmed by transmission and immunoelectron microscopic studies. The addition of Tc into the medium led to the halting of rat UOX gene transcription. As a result, recombinant rat UOX mRNA was lost rapidly followed by loss of crystalloid cores structures and UOX protein degradation. Lysosomes assembled around the UOX specific structures indicating that they were involved in degradation of the protein. The observations suggest that the entire organelle rather than a single protein within the peroxisomes is degraded once the rat UOX gene expression is turned off, and the phagocytic vacuole/lysosome pathway (microautophagic process) may play an important role in degradation of the protein under the present situation.

Animals↗

PubMed2005

Activation of PAR4 induces a distinct actin fiber formation via p38 MAPK in human lung endothelial cells.

Protease-activated receptors (PARs) are multifunctional G protein-coupled receptors. Among the four existing PARs, PAR4 is preferentially expressed in the human lung tissue. However, the function of PAR4 has not been defined in the lung endothelial cells. Because PAR1-mediated cellular effects are deeply related to the morphological changes, we focused on the actin fiber and p38 mitogen-activated protein kinase (MAPK) signaling involved in actin polymerization to elucidate the role of PAR4. RT-PCR and Western blot analyses identified PAR4 expression in human pulmonary artery endothelial cells and in human microvascular endothelial cells from lung. We then examined the changes in actin fibers in endothelial cells treated with PAR4-activating peptide. PAR1-activating peptide was used for comparison. Activation of PAR4 and PAR1 by their corresponding peptides induced actin fiber formation; however, the actin filaments were broadly bundled in PAR4 as compared with the ringlike actin filaments in PAR1 activation. Correspondingly, the magnitude of p38 MAPK phosphorylation was different between cells treated with PAR4 and PAR1, with PAR4-activating peptide showing a significantly higher sensitivity to p38 MAPK inhibitor, SB203580. Taken together, these results demonstrate that activation of PAR4 results in the formation of actin fiber distinct from that by PAR1 activation, suggesting PAR4 may play specific roles in the lung endothelial cells.

Actin Cytoskeleton↗

PubMed2005

Occurrence of hyaline droplets in renal biopsy specimens: an ultrastructural study.

Hyaline droplets are apical cytoplasmic vesicles containing an accumulation of electron-dense amorphous materials surrounded by a unit membrane. Hyaline droplets may originate from apical vesicles after conversion to osmotic vesicles and loss of internally lined glycocalyx. They are found in the proximal tubular epithelium in biopsies from patients with renal diseases; however, their biological importance is not well understood. We reviewed ultrastructural pathology records of 140 renal biopsy patients to determine the occurrence and relevance of hyaline droplets. Of the cases, 14 (10%) showed the presence of hyaline droplets in proximal tubular epithelium. The distribution of cases were 8 of the 19 (42%) with minimal change nephritic syndrome, 2 of the 37 (5%) with IgA nephropathy, 2 of the 4 (50%) with membranous glomerulonephropathy, 1 of the 4 (25%) with tubulointerstitial nephritis, and 1 of the 1 (100%) with acute renal failure. The droplets were frequently found in male patients (86%), never in children, and were mostly associated with tubular necrosis (8 of 14 cases; 56%). Many hyaline droplets were observed in the cytoplasm of necrotic proximal tubular epithelial cells, and even when tubular necrosis was not evident, the proximal tubular epithelial cells containing hyaline droplets showed degenerated microvilli and decreased basal interdigitations. These results suggest that hyaline droplets could be one marker of renal tubular necrosis and a sign of functional disorder of protein reabsorption by degenerating proximal tubular epithelium.

Adult↗

PubMed2005

Global gene expression analysis of keloid fibroblasts in response to electron beam irradiation reveals the involvement of interleukin-6 pathway.

Keloid is a dermal fibroproliferative lesion of unknown etiology that commonly recurs after surgical excision. Post-operative adjuvant electron beam (EB) irradiation has been successfully used to reduce keloid recurrences. To provide new insights into the molecular mechanism behind the effect of EB irradiation, we used a cDNA microarray screening of more than 5000 genes to assess early changes in gene expression between EB-irradiated and non-irradiated keloid and non-lesional dermal fibroblasts. Primary fibroblast cultures from keloid and associated non-lesional dermis obtained from five patients were exposed to 15 Gy EB irradiation and analyzed after 15 min incubation. Early response to EB irradiation showed that 96 (1.8%) genes were modulated 2-fold or more in keloid fibroblasts. Upregulated genes accounted for 29.2% (28 genes), whereas downregulated genes comprised 70.8% (68 genes), indicating a silencing of many genes in keloid fibroblasts after EB irradiation. Many of the downregulated genes play roles in the enhancement of cell proliferation and extracellular matrix production, whereas several of the upregulated genes involves in the promotion of apoptosis and extracellular matrix (ECM) degradation. Using emerging bioinformatic tools and further corroboration, the interleukin 6 (IL-6) signaling pathway was found to be mainly involved in EB irradiation response. We also showed co-expression of IL-6 and its specific receptor (IL-6Ralpha) in keloid fibroblasts that points to the existence of an IL-6 autocrine loop in these cells. These results suggested that at the molecular level, EB irradiation might hinder keloid formation by regularizing disturbances in the homeostatic equilibrium between inducer and inhibitor activities in the matrix system most likely through the IL-6 pathway. Our study provides clues for the molecular mechanism(s) behind the beneficial effect of EB irradiation in reducing keloid recurrences and may help develop alternative strategies for the therapy and prophylaxis of this lesion.

Adult↗

PubMed2005

Reversing the effects of formalin fixation with citraconic anhydride and heat: a universal antigen retrieval method.

Formalin is a commonly used fixative for tissue preservation in pathology laboratories. A major adverse effect of this fixative is the concealing of tissue antigens by protein cross-linking. To achieve a universal antigen retrieval method for immunohistochemistry under a constant condition, we developed a new method in which the effects of formalin fixation were reversed with citraconic anhydride (a reversible protein cross-linking agent) plus heating. Formalin-fixed, paraffin-embedded tissues from various organs were examined for immunohistochemical localization of a wide variety of antigens. Deparaffinized tissue sections were placed in an electric kitchen pot containing 0.05% citraconic anhydride solution, pH 7.4, and the pot was set at "keep warm" temperature mode of 98C for 45 min. This mode allowed heating the sections at a constant temperature. The sections were then washed in buffer solution and immunostained using a labeled streptavidin-biotin method using an automated stainer. In general, formalin-fixed tissues demonstrated specific immunostainings comparable to that in fresh frozen tissues and significantly more enhanced than after conventional antigen retrieval methods. In particular, even difficult-to-detect antigens such as CD4, cyclin D1, granzyme beta, bcl-6, CD25, and lambda chain revealed distinct immunostainings. Different classes of antigens such as cellular markers and receptors, as well as cytoplasmic and nuclear proteins, consistently produced enhanced reactions. This method provides efficient antigen retrieval for successful immunostaining of a wide variety of antigens under an optimized condition. It also allows standardization of immunohistochemistry for formalin-fixed tissues in pathology laboratories, eliminating inter-laboratory discrepancies in results for accurate clinical and research studies.

Antigens↗

PubMed2005

Demonstration of microvessel networks and endothelial cell phenotypes in the normal murine lung.

The vascular endothelial cells (ECs) express various antigens related to coagulation factors, including factor VIII-related antigen or von Willebrand factor (vWF) in the cytoplasm and thrombomodulin (TM; a thrombin receptor)along the plasma membrane. CD34 (a hematogenic stem cell marker) is also expressed along the surface membrane of the ECs. Using these EC markers and fluorescein-isothiocyanate-labeled dextran (FITC-dextran)(Sigma Co., St. Louis, MO), we attempted to demonstrate the complex network of microvessels and their EC phenotypes in tracheo-bronchial trees and lung parenchyma of the normal adult ICR male mice. Under anesthesia, saline with heparin was infused slowly through left ventricle to drain off the blood. Following brief fixation with 4% buffered paraformaldehyde solution (PFA) through the same route, one group of animals received, 1) FITC-dextran injection via left ventricle, and the large airways and lungs were further fixed in PFA, or 2) The airways and lungs of the other group were rapidly frozen, and the thin sections were stained with two antibodies of vWF and Alexa Fluor 594-labeled CD34. The vWF antibody was later labeled by FITC. The microvessels of airways and lungs were observed by a laser scanning confocal microscope (TC-SP, Leica, Heidelberg, Germany). The phenotypic characteristics of microvessel ECs appeared mostly identical with those described previously in the human lung, although CD34 was applied instead of TM in the present study. The topographical heterogeneity of immunohistochemical properties of ECs would suggest functional differences at different sites of the lung, that would provide a novel insight for understanding the pathogenesis of human lung diseases.

Animals↗

PubMed2004

Comparative study between DNA copy number aberrations determined by quantitative microsatellite analysis and clinical outcome in patients with stomach cancer.

PURPOSE: We detected the relative DNA copy numbers (RCNs) at target loci in patients with stomach cancer with quantitative microsatellite analysis. We additionally clarified the relationship between DNA copy number aberrations and the clinical outcome of the patients. EXPERIMENTAL DESIGN: Fresh frozen samples were obtained from 30 patients who had undergone surgery for stomach cancer. Seven microsatellite loci in chromosomes 8q, 16q, and 20q and one gene-specific locus (ZNF217) were selected as the target loci. The DNA copy number was obtained relatively to a pooled reference consisting of six microsatellite primer sets selected from the regions where few aberrations have been reported in comparative genomic hybridization analysis. On the basis of the TaqMan PCR system, the internal probes used were carrying donor (6-carboxyfluorescein) and acceptor (6-carboxytetramethylrhodamine) fluorescent molecules complementary to CA repeats in the microsatellite markers and to one gene-specific oligomer in the gene-specific marker. RESULTS: Chromosome 8q gain, 20q gain, and 16q loss were detected in 18 (60.0%), 8 (26.7%), and 13 (43.3%) cases, respectively. Gains in the RCNs of D8S1801 and D8S1724 were most frequently found (36.7%). There was a significant correlation between the loss of D16S3026 and reduced survival duration (P = 0.0158), and the simultaneous aberrations of D8S1801 gain and D16S3026 loss (double marker positive) was significantly associated with reduced survival duration (P = 0.0008). According to Cox proportional hazards model, the double marker positive was a significant and independent factor indicating an unfavorable prognostic factor (relative risk, 17.176; 95% confidence interval, 2.782-106.026; P = 0.0022). CONCLUSION: RCN aberrations in tumor tissues determined by quantitative microsatellite analysis enable identification of the prognostic factors that correlate with clinical outcome of the patients with stomach cancer.

Aged↗

PubMed2004

Human airway trypsin-like protease induces PAR-2-mediated IL-8 release in psoriasis vulgaris.

Human airway trypsin-like protease (HAT), a novel serine protease in the airways, enhances cell growth and IL-8 production. The expression and role of HAT in the skin however, is unknown. Immunofluorescence staining and reverse transcription (RT)-PCR were done to know HAT production in normal and psoriatic tissues and keratinocyte cell lines. Cell growth and/or IL-8 release analyses were made by bromo-deoxyuridine (BrdU) uptake and ELISA. Psoriatic epidermis showed more extensive immunofluorescence expression of HAT, and less extensive expression of protease-activated receptor (PAR)-2. RT-PCR demonstrated a higher HAT and a lesser PAR-2 mRNA expressions in psoriatic epidermis. Normal keratinocyte and epidermoid carcinoma cell lines expressed HAT and PAR-2 mRNA, and immortalized keratinocytes (HaCaT) expressed PAR-2, but not HAT mRNA. PAR-2 was detected along the keratinocyte surface in culture and became invisible upon HAT stimulation, suggesting a process of its internalization. HAT or PAR-2 activating peptide did not enhance BrdU uptake, but induced an IL-8 release. Treatment with HAT and IL-1beta synergistically increased the effect of IL-8 release. Inhibition of PAR-2 resulted in a decreased HAT-induced IL-8 release. Thus, HAT might promote PAR-2-mediated IL-8 production to accumulate inflammatory cells in the epidermal layer of psoriasis.

Adult↗

PubMed2004

Differential expression of protease-activated receptors 1, 2, and 4 on human endothelial cells from different vascular sites.

OBJECTIVE: Protease-activated receptors (PARs) mediate DNA synthesis in endothelial cells when activated by serine proteases. However, despite the existence of heterogeneity among endothelial cells from each tissue, the responses to PAR-1, PAR-2, and PAR-4 activation are poorly defined and compared between endothelial cells from different sites. The aim of this study was to investigate whether PAR-mediated DNA synthesis differed in various endothelial cell types. METHODS: We examined the incorporation of BrdU by human pulmonary artery endothelial cells (HPAECs), human aortic endothelial cells (HAECs), and human umbilical vein endothelial cells (HUVECs). RESULTS: When the endothelial cells were treated with the selective PAR-1-activating peptide, SFLLRN, HAECs showed the highest BrdU incorporation rate (182 +/- 28%). In contrast, treatment with the PAR-2-activating peptide, SLIGKV, resulted in the highest BrdU incorporation rate (173 +/- 37%) in HPAECs, when pretreated with TNF-alpha. The PAR-4-activating peptide, GYPGQV, induced DNA synthesis in HPAECs and HAECs, but not in HUVECs. CONCLUSION: These findings suggest that each PAR preferentially targets an endothelial cell type, and thus plays a distinct role in diverse physiological or pathological conditions.

Aorta↗

PubMed2004

Effect of ionizing irradiation on human esophageal cancer cell lines by cDNA microarray gene expression analysis.

To provide new insights into the molecular mechanisms underlying the effect of irradiation on esophageal squamous cell carcinomas (ESCCs), we used a cDNA microarray screening of more than 4,000 genes with known functions to identify genes involved in the early response to ionizing irradiation. Two human ESCC cell lines, one each of well (TE-1) and poorly (TE-2) differentiated phenotypes were screened. Subconfluent cells of each phenotype were treated with single doses of 2.0 Gy or 8.0 Gy irradiations. After a 15 min incubation time-point, the cells were collected and analyzed. Compared with non-irradiated cells, many genes revealed at least 2-fold upregulation or downregulation at both doses in well or poorly differentiated ESCC cells. The common upregulated genes in well and poorly differentiated cell types at both irradiation doses included SCYA5, CYP51, SMARCD2, COX6C, MAPK8, FOS, UBE2M, RPL6, PDGFRL, TRAF2, TNFAIP6, ITGB4, GSTM3, and SP3 and common downregulated genes involved NFIL3, SMARCA2, CAPZA1, MetAP2, CITED2, DAP3, MGAT2, ATRX, CIAO1, and STAT6. Several of these genes were novel and not previously known to be associated with irradiation. Functional annotations of the modulated genes suggested that at the molecular level, irradiation appears to induce a regularizing balance in ESCC cell function. The genes modulated in the early response to irradiation may be useful in our understanding of the molecular basis of radiotherapy and in developing strategies to augment its effect or establish novel less hazardous alternative adjuvant therapies.

Carcinoma, Squamous Cell↗

PubMed2003

Protease-activated receptor (PAR)-1 and PAR-2 participate in the cell growth of alveolar capillary endothelium in primary lung adenocarcinomas.

BACKGROUND: Cell growth can be induced via elicitation of protease-activated receptors (PAR) with serine proteases such as thrombin and trypsin. METHODS: To understand whether PAR are involved in tumor vessel formation in the neoplastic cell-bearing alveolar walls, immunohistochemical and reverse transcriptase-polymerase chain reaction analyses were performed using the lung tissues from 16 patients with primary lung adenocarcinomas. RESULTS: In microdissected tumor alveolar walls, the expressions of PAR-1 and PAR-2 mRNA were increased by 10-fold (P < 0.05) and 16-fold (P < 0.01), respectively, as compared with normal alveolar walls. Confocal microscopy revealed that tumor capillary endothelial cells in alveolar walls lost thrombomodulin expression. Instead, the expression of PAR-2 often became obvious at the normal border. Both PAR-1 and PAR-2 were expressed in the microvessel endothelial cells in tumors. Trypsin mRNA was expressed in 7 of the 16 cancer cell-bearing tissue specimens in contrast to 1 of the 14 normal alveolar walls. Immunohistochemically, trypsin was positive in the neoplastic cells from 10 patients and in lung adenocarcinoma cell lines (A549, HLC-1, LC-2, and PC-14). An in vitro assay showed a significant increase in idoxuridine (IdU) or bromodeoxyuridine uptake in human pulmonary artery endothelial cells and human umbilical cord vein endothelial cells after treatments with alpha-thrombin or activating peptides; SFLLRN for PAR-1 and SLIGKV for PAR-2, respectively. CONCLUSIONS: Thus, proliferation of alveolar capillary endothelial cells is initialized in part by PAR activation with serum thrombin and neoplastic cell-released trypsin. These results suggest a synergistic effect of PAR with vascular endothelial growth factor in alveolar angiogenesis.

Adenocarcinoma↗

PubMed2003

Identification of an electron densification of the glomerular basement membrane in renal biopsy specimens.

Ultrastructural examination of renal biopsy specimens is often necessary to establish a diagnosis. We have noted, in some renal biopsies, that normal-appearing glomerular basement membrane (GBM) shows an electron densification. The aim of this study was to describe this phenomenon and assess the degree of its occurrence. We reviewed ultrastructural pathology records of 153 renal biopsy patients with special reference to the careful examination of the electron micrographs. Of these, 28 cases (18%) showed a definite and homogeneous electron densification of normal-appearing GBM in the glomeruli. The pathological diagnosis in these cases was IgA nephropathy in 15, minimal change nephrotic syndrome in 6, interstitial nephritis in 3, membranoproliferative glomerulonephritis in 2, and nephritis of Henoch-Schonlein purpura and membranous nephropathy in 1 case each. In addition, frequent deposition of IgG without C3 in the GBM (86%) and glomerular endothelial cell edema (96%) were observed. No apparent correlation could be ascertained between the presence of the electron densification and pathological diagnosis. It is suggested that electron densification of the GBM may be caused by the penetration of some electron-dense materials into the GBM as a result of an abnormality in the glomerular filtration barrier and that this could be considered as a sign of altered properties of the lamina densa.

Adolescent↗

PubMed2003

Expression of p73 and c-Abl proteins in human ovarian carcinomas.

The p73, a homologue of the p53 tumor suppressor protein, has a pro-apoptotic activity which is induced by the c-Abl, a protein tyrosine kinase appearing in the nucleus and cytoplasm of proliferating cells. However, the role of p73 and c-Abl in ovarian cancer is not well-defined. We investigated immunohistochemical expressions of p73 and c-Abl in 64 ovarian carcinomas, 13 borderline and 14 benign ovarian tumors to elucidate their clinicopathological relevances. Of the malignant, borderline, and benign ovarian tumors, respectively, 33 (51%), 10 (77%) and 13 (93%) had negative or low p73 expression, 31 (48%), 3 (23%) and 1 (7%) had high p73 expression, 23 (36%), 5 (38%) and 10 (71%) had negative or low c-Abl expression, and 41 (64%), 8 (61%) and 4 (29%) had high c-Abl expression. A high p73 or c-Abl expression was significantly associated with ovarian carcinomas as compared to benign tumors (p=0.003 and p=0.03 respectively). In addition, a significant correlation was found between the high p73 expression and disease stage (p=0.04) and patient's survival (p=0.02). No correlation was found with c-Abl expression. These results reveal an association of p73 overexpression with advanced ovarian carcinomas which may suggest the p73 overexpression as an indicator of poor prognosis.

Biomarkers, Tumor↗

PubMed2003

Cisplatin may induce frataxin expression.

Cisplatin is a widely used drug in cancer chemotherapy and resistance to cisplatin is a major limitation for its successful application. Intracellular inactivation of cisplatin and detoxification of reactive oxygen species (ROS) by glutathione (a crucial cellular antioxidant) is a mechanism for cisplatin resistance. During cDNA microarray analyses of differential gene expression between a cisplatin-resistant A2780CP70 human ovarian carcinoma cell line and its parental A2780 cell line, we discovered that frataxin gene expression was frequently overexpressed in the cisplatin-resistant variant. Decreased expression of frataxin protein is associated with Friedreich's ataxia (FRDA) which is a neurodegenerative disease involving ROS-mediated cellular damage. Recent evidence suggests that frataxin might detoxify ROS via activation of glutathione peroxidase and elevation of thiols. To exploit potential involvement of frataxin gene in the development of resistance to cisplatin, we compared the levels of frataxin gene and protein in the cisplatin-resistant A2780CP70 ovarian carcinoma cell line and its parental A2780 cell line. We found that frataxin mRNA and protein expressions were elevated in the cisplatin-resistant cells. Our results suggest a potential role for cisplatin as an inducer of frataxin expression and implies that this gene may be a potential target for modulating the response to cisplatin. This is the first report showing an association between frataxin expression and cisplatin resistance.

Cisplatin↗

PubMed2003

Association of ovarian tumor epithelium coexpressing HLA-DR and CA-125 antigens with tumor infiltrating cytotoxic T lymphocytes.

Understanding of the relationship between tumor infiltrating cytotoxic T lymphocytes (CD 8(+)TILs) and tumor cells as well as tumor-associated antigens is important and may reflect the extent of immune response of the patient to the tumor, thus providing a useful clue relevant to the prognosis. The purpose of this study was to determine the relationship between the expression of HLA-DR and CA-125 antigens and the presence of CD 8(+)TILs with regard to the established clinicopathological factors of ovarian carcinomas using immunohistochemical methods. Thirty-one ovarian carcinomas consisting of 20 serous, 7 mucinous, and 4 clear cell types were examined. Of these, 18 (58%) and 22 (71%) were positive for HLA-DR and CA-125 antigens respectively, and the overall mean number of the CD 8(+)TILs was 7.2+/-2.9. A significant association was observed between the mean number of CD8(+)TILs and tumor grade (P=0.01), disease stage (P=0.003), and patient outcome (P=0.01). The mean number of CD 8(+)TILs in HLA-DR positive (8.6+/-2.2) or CA-125 positive (8.4+/-2.1) tumors was significantly higher than that in HLA-DR negative (5.2+/-2.5; P=0.0003) or CA-125 negative (4.2+/-2.2; P=0.00002) tumors. These significant levels were further enhanced by one order of magnitude when the mean number of CD 8(+)TILs in tumors positive for both HLA-DR and CA-125 antigens (9.1+/-1.7) was compared to that in HLA-DR negative or CA-125 negative tumors. The frequency of cancer-related deaths in HLA-DR and CA-125 positive tumors was significantly lower than in the negative tumors (P=0.01). These data suggest that concurrent expression of HLA-DR and CA-125 antigens may augment the immune response of the patient to the tumor, thus providing a potential clue relevant to the prognosis.

Adenocarcinoma, Mucinous↗