[Relationship between VEGF-C expression and nasopharyngeal carcinoma proliferation and metastasis].

OBJECTIVE: To detect the expression of VEGF-C in nasopharyngeal carcinoma (NPC) and explore its relationship with proliferation and metastasis of NPC. METHODS: Biopsy specimens of 62 NPC patients were divided into 2 equal portions, one for immunohistochemical staining with VEGF-C polyclonal antibody by streptavidin peroxidase method, another for flow cytometry with Ki67 antibody to analyze the proliferation of tumors. The patients were followed up periodically, and then their 3-year survival and the cause of death were statistically analyzed. RESULTS: Of the 62 patients, the percentage of VEGF-C positive cells in the tumors ranged from 0 - 82%, 17 (27.4%) were negative, 13 (21.0%) weak positive, 18 (29.0%) moderate positive and 14 (22.6%) strong positive. Ki67 positive tumor cells ranged from 0 - 52%, 40 cases (64.5%) showed low expression which include 15 cases of negative, 22 (35.5%) showed high expression. There was a direct relationship between the expression of VEGF-C and Ki67 (r = 0.323, P < 0.05). The 3-year survival rate of 62 patients was 66.1%. The expression of VEGF-C in the patients with positive lymph node was much higher than that with negative lymph node (P < 0.01). Among the 8 patients with distant metastasis, their VEGF-C expression was strong positive while among the 21 disease free survival patients, their VEGF-C expression was (-) or (+) account for 80.9%. An inverse correlation was found between the VEGF-C expression and prognosis of NPC patients, but the difference has no statistical significance (r = -0.219, P > 0.05). CONCLUSION: High expression of VEGF-C is related with proliferation and metastasis of NPC cells. It is not an independent prognostic factor, but a predictive marker of disease-free survival of NPC patients.

[Inhibitory effects of tetraethylammonium on proliferation and voltage-gated potassium channels in human cervical carcinoma cell line SiHa].

BACKGROUND & OBJECTIVE: Various potassium channels are known to be involved in proliferation of many malignant cell lines. This study was to explore the role of voltage-gated potassium channels in proliferation of human cervical carcinoma cells through observing the effects of tetraethylammonium (TEA) on proliferation and outward potassium currents in human cervical carcinoma cell line SiHa. METHODS: SiHa cells were treated with TEA. The effect of TEA on proliferation of SiHa cells was assessed by MTT assay. Cell apoptosis and cell cycle were detected by flow cytometry with Hoechst 33258 staining. The outward potassium currents were recorded by patch clamp technique. RESULTS: TEA inhibited the proliferation of SiHa cells in dose-and time-dependent manners, and induced cell apoptosis. The cell cycle was arrested at G0/G1 phase after treatment with TEA. Exposure of SiHa cells to 10 mmol/L TEA reduced the peak outward potassium currents significantly from (260+/-12) pA to (58+/-6) pA (P<0.01). CONCLUSIONS: Voltage-gated potassium channels play an important role in regulating proliferation of cervical carcinoma SiHa cells. Blocking voltage-gated potassium channels could inhibit proliferation of SiHa cells.