[Effects of cisplatin on telomerase activity of human choroidal melanoma cells].

OBJECTIVE: To study the effects of CDDP (cis-dichlorodiamine platinum) on the telomerase of human choroidal melanoma cells and to investigate the toxic effects of CDDP on these cells. To study the relationship between these two effects and to explore the possibility of using CDDP in the chemotherapy of choroidal melanoma. METHODS: It was an experimental research. CDDP was added to the culture medium of primary cultured human choroidal melanoma cells at different concentrations (0.01, 0.1, 1, 10 and 100 mg/L, 72 h) and times (12, 24, 48, 72 and 96 h, 10 mg/L) and the results were compared with that of the controls. Toxic effects of CDDP were evaluated by MTT test and the level of telomerase was measured by PCR-ELISA assay. The correlation between these two effects was analyzed. RESULTS: The telomerase activity was inhibited by CDDP time dependently and dose dependently. Cell viability was decreased when the concentration of CDDP attained 0.1 mg/L and acted for 24 hours. The cell toxicity of CDDP was correlated negatively (r = -0.900, P = 0.037) with the inhibition of telomerase. The cell death was lagged behind the decrease of telomerase. CONCLUSIONS: CDDP is an effective telomerase inhibitor which can decrease the telomerase activity of cultured human choroidal melanoma cells significantly. This effect is dose and time dependent. CDDP can also cause the death of cultured melanoma cells.

Vitronectin significantly influences prognosis in osteosarcoma.

Vitronectin (Vn), a multifunctional adhesive protein, is found in association with tumor progression, angiogenesis and metastasis in a variety of (human) tumors. But no studies concerning its correlation to osteosarcoma prognosis were found. Hence, we aimed to investigate the prognostic value of Vitronectin (Vn) in osteosarcoma. Here, we studied the expression of VN in the tumor tissues from 67 patients with osteosarcoma and 20 patients with osteochondroma using immunohistochemistry and estimated the effects of VN expression in osteosarcoma on progression-free survival (PFS) and overall survival (OS) using the Kaplan-Meier curve and COX proportional hazards regression model. Increased expression of VN in osteosarcoma tissue compared to no VN expression in osteochondroma tissue was shown in immunohistochemical assay. No associations were observed between VN expression and osteosarcoma patients' gender (P = 0.675), age (P = 0.813), tumor size (P = 0.436), histologic subtype (P = 0.0.543) or tumor location (P = 0.456). Univariate survival analysis demonstrated significant correlations of high VN expression with shorter PFS (P = 0.002) and OS (P = 0.001); multivariate survival analysis revealed high VN expression as a significant independent prognostic indicator for shorter PFS (HR 2.788, P = 0.003) and OS (HR2.817, P = 0.003). In conclusion, the high expression of VN in tumor cells independently indicated poor clinical prognosis in patients with osteosarcoma, other than large tumor size and non-neoadjuvant chemoradiotherapy, suggesting that VN may serve as a potential therapeutic target in osteosarcoma.