[Association of EGFR expression with angiogenesis and chemoresistance in ovarian carcinoma].

OBJECTIVE: To clarify the association of EGFR expression with angiogenesis and chemoresistance in ovarian cancer. METHODS: Immunohistochemical PV-6000 staining was used to detect the expression of EGFR, LRP protein and MVD in 102 ovarian tumor specimens. RESULTS: EGFR, LRP positive rates and MVD in borderline and malignant ovarian specimens were significantly higher than those in the normal and benign ones (P < 0.01). EGFR positive expression rate in stage III-IV carcinoma tissues, poor differentiation and with ascites was higher than that in stage I-II carcinomas of well differentiation and without ascites (P < 0.05). MVD was related to histological grade, residual tumor and ascites, LRP positive expression had no correlation with the clinicopathologic parameters (P > 0.05). The effective rate of chemotherapy in patients with EGFR and LRP-positive expression were 57.1% and 53.7%, respectively, significantly lower than that in cases with EGFR and LRP-negative expression (85.0% and 90.9%, P < 0.05). In the 64 cases with complete data, the three-year survival rate was 53.0%. The survival time was shorter in the cases with EGFR and LRP-positive expression, poor differentiation, ascites and chemoresistance (P < 0.01), and only LRP-positive expression and chemotherapeutic effect were independently related to survival time (P < 0.05). There was a correlation between EGFR and MVD (r = 0.548, P < 0.01), EGFR and LRP positive expression (P = 0.020). CONCLUSION: The expression of EGFR in ovarian cancer is related to angiogenesis and chemoresistance. EGFR and LRP-positive expression are related to chemoresistance, and detection of the two proteins may be helpful in guiding chemotherapy choice for ovarian cancer. LRP-positive expression and chemotherapeutic effect may be independent prognostic factors.

Vascular endothelial growth factor activating matrix metalloproteinase in ascitic fluid during peritoneal dissemination of ovarian cancer.

The role of vascular endothelial growth factor (VEGF) during peritoneal dissemination of ovarian carcinoma and the association with tumor microvessel density (MVD) and matrix metalloproteinase (MMP) activity was investigated. To this end, MVD, tumor tissue and ascitic fluid levels of VEGF, and MMP activity of ascitic fluid were examined in patients with ovarian cancer and benign ovarian tumor. The effect of ascites on cell growth, cell invasion activity and angiogenesis was investigated in vitro. Ascitic fluid and tumor tissue samples were obtained from 15 patients with benign ovarian tumor and 24 patients with ovarian carcinoma. Tissue extract and ascitic fluid levels of VEGF were measured using enzyme immunoassay. Tumor microvessels were detected immunohistochemically. MMP activity was measured by gelatin zymography. For the in vitro experiment, the SKOV-3 human ovarian carcinoma cell line was utilized. Cell growth was examined using MTT-assay, cell invasion activity was measured by Matrigel in vitro invasion assay, and neovascularization was assessed using an angiogenesis kit. VEGF levels in tissue extract and ascitic fluid, MVD, expression of active form MMP-2 in ascitic fluid and ascites volume were higher in ovarian cancer patients than in benign ovarian tumor patients. In addition, these were elevated in stage III and IV diseases compared to stage I and II diseases in ovarian cancer patients. MVD and expression of active form MMP-2 in ascitic fluid were closely correlated with VEGF level in tissue extracts, and MVD and ascites volume were closely correlated with VEGF level in ascitic fluid. Cell invasive activity and angiogenesis activity increased when cells were exposed to ascites. These increases were apparent when exposed to ascites obtained from ovarian cancer patients and were related to VEGF concentrations of ascitic fluid and expression of active form MMP-2 in ascitic fluid. The increased VEGF secreted from tumor cells is suggested to enhance tumor growth through angiogenesis, to produce ascites and to elevate ascitic VEGF concentrations and expression of active form MMP-2. The progression of peritoneal involvement may be induced by elevated VEGF and expression of active form MMP-2, followed by increased VEGF in the primary tumor. Control of VEGF in the primary tumor may become an effective strategy against peritoneal dissemination of ovarian carcinoma.

Study on tumor angiogenesis in epithelial ovarian carcinoma.

To investigate tumor angiogenesis in benign, borderline and malignant epithelial ovarian tumors and its relation with the pathogenesis of ovarian carcinoma, polycolonal antibody directed against human von Willebrand factor (factor VIII) was used to measure the microvessel density (MVD) in 66 cases (11 benign, 10 borderline, and 45 malignant) of epithelial ovarian tumors by using immunohistochemistry. The results showed that the mean MVD in epithelial ovarian cancer (31.7 +/- 11.2, 400 X) was higher than in benign and borderline tumors (16.7 +/- 6.3, 20.7 +/- 8.8 respectively, P < 0.05). There was no difference in MVDs among those in different tumor grades (P > 0.05). But there was significant difference in MVDs among those in different tumor stages (P < 0.05). MVD in stage III-IV cancer was higher than that in stage I-II (P < 0.05). It is concluded that the tumor angiogenesis is an early event in ovarian tumorgenesis. The increased tumor micovessel might be responsible for tumor development.