Silencing of microRNA-3175 represses cell proliferation and invasion in prostate cancer by targeting the potential tumor-suppressor SCN4B.

MicroRNA-3175 (miR-3175) expression is upregulated in prostate cancer, but its roles and the underlying mechanisms in prostate cancer cell growth and invasion need to be elucidated. This study aimed to uncover the roles of miR-3175 in regulating cell growth and migration, as well as the expression of its predicted target gene cardiac sodium channel ß4-subunit gene (SCN4B). Real-time quantitative PCR (RT-qPCR) and/or western blotting techniques were used to measure miR-3175 and SCN4B expression levels in prostate cancer cells. Inhibitor or mimics transfections were used to overexpress or silence miR-3175 in prostate cancer cells. MTT and Edu assays were applied to assess cell viability. Scratch assay and transwell chambers were used to examine cell migration and invasion abilities. The interaction between miR-3175 and SCN4B was determined by means of luciferase gene reporter, RT-qPCR, and western blotting assays. The results showed that miR-3175 expression was increased and SCN4B expression was decreased in prostate cancer cell lines as compared with normal human prostatic epithelial cells. Compared with the control group, knockdown of miR-3175 resulted in strong inhibitions of cell growth, migration, invasion, and N-cadherin expression, together with an increase in E-cadherin expression. In addition, knockdown of miR-3175 dramatically increased the luciferase activity of the luciferase vector of SCN4B, and increased SCN4B expression. Together, this study illustrated that downregulation of miR-3175 repressed the proliferation and invasion of prostate cancer cells, which might be induced by SCN4B downregulation.

[Evidence for determining the safe surgical margin for pleomorphic adenoma of parotid gland].

OBJECTIVE: To compare the treatment outcomes, complications and histopathologic features between conventional parotidectomy and functional regional parotidectomy in the treatment for pleomorphic adenoma of parotid gland and to provide clinical, and pathological evidence for determining the safe surgical margin. METHODS: Of 109 patients, 60 patients received conventional parotidectomy and 49 patients received functional regional parotidectomy. The rates of tumor recurrence and complications were compared between the groups of patients. RESULTS: There was no significant difference in the incidence of tumor recurrence, the facial paralysis and sialosyrinx between two groups. The rates of Frey's syndrome, numbness of auricular region, and facial asymmetry were 30.0%, 61.7%, and 38.3% in the patients with conventional parotidectomy respectively, while the rates were 6.1%, 30.6%, and 8.2% in the patients with functional regional parotidectomy, with significant statistically difference, respectively (P < 0.05). Of 109 patients, 33 with incomplete capsule, 29 with capsule penetration, 25 with pseudopodia, and 13 with satellite nodules. There was no significant difference in the depth of tumor infiltration between two groups of patients. For the tumor smaller than 2 cm, the depth of infiltration in conventional group was from 0.061 to 1.122 mm, functional group was from 0.442 to 3.127 mm (Z = -1.093, P = 0.057); for the tumors between 2 - 4 cm, the depth in conventional group was from 0.081 to 7.908 mm, functional group was from 0.082 to 6.632 mm (Z = -0.214, P = 0.831); for the tumor larger than 4 cm, the depth of infiltration was from 0.340 to 8.476 mm. CONCLUSIONS: Compared with conventional parotidectomy, functional regional parotidectomy has good outcomes and less complications. The surgical margins of pleomorphic adenomas of the parotid gland should be determined by the size of tumor. The 1 cm-surgical margins are safe for the tumors less than 4 cm, and the tumors more than 4 cm should be treated with superficial parotidectomy.