RNAi-mediated human Nestin silence inhibits proliferation and migration of malignant melanoma cells by G1/S arrest via Akt-GSK3ß-Rb pathway.

Human Nestin (hNestin) has been found to express in melanoma, and its expression is positively correlated with the advanced stage of melanoma. However, the precise role of hNestin in the development of melanoma has not been fully understood. The present study aimed to explore the role of hNestin in the proliferation and invasion of melanoma cells. The lentivirus vector carrying a short hairpin RNAs (shRNAs) targeting hNestin (hNestin-shRNA-LV) was stably infected into human melanoma cells UACC903, which expressed high levels of hNestin. The effects of hNestin knockdown on the proliferation, apoptosis, migration of melanoma cells and the related signaling pathways were investigated by immunofluorence, Western blotting and reverse transcription polymerase chain reaction (RT-PCR), respectively. The results showed that hNestin was expressed in most melanoma specimens and the melanoma cells studied. Knockdown of hNestin expression significantly inhibited the proliferation of melanoma cells, blocked the formation of cell colony, arrested cell cycle at G1/S stage and suppressed the activation of Akt and GSK3ß. hNestin-silent cells also showed a sheet-like appearance with tight cell-cell adhesion, decreased membrane expression of N-cadherin and ß-catenin, and attenuated migration. Furthermore, hNestin silence resulted in the inhibition of tumor growth in vivo. Our study indicates that hNestin knockdown suppresses the proliferation of melanoma cells, which might be through affecting Akt-GSK3ß-Rb pathway-mediated G1/S arrest, and hNestin silence inhibits the migration by selectively modulating the expression of cell adhesion molecules in the process of epithelial-mesenchymal transition.

[Expression of circadian gene NPAS2 in colorectal cancer and its prognostic significance].

OBJECTIVE: To study the expression of NPAS2 in colorectal cancer (CRC) and analyze its relationship with the clinicopathological parameters and prognosis of the patients. METHODS: Real-time q-PCR was used to detect the expression of NPAS2 mRNA in 40 fresh CRC tissues and paired adjacent tissues; immunohistochemistry was used to detect the expression of NPAS2 protein in 120 paraffin-embedded tumor and adjacent tissues. The relationship between NPAS2 expression level and the 5-year survival rate of 78 CRC patients with follow-up data were analyzed with Kaplan-Meier survival analysis. RESULTS: Compared with the adjacent tissues, fresh CRC tissue expressed significantly lower NPAS2 mRNA levels (P<0.01). Among the paraffin-embedded CRC tissues, 19.2% were positive for NPAS2 expression, as compared to a much higher rate of 62.5% in the adjacent tissues (P<0.05). The expression of NPAS2 was correlated with the tumor size, lymph node metastasis and TNM stages (P<0.05) but not with the patients' gender, age, distant tumor metastasis, differentiation, or invasion. Patients with high NPAS2 expression levels had a significantly higher 5-year survival rate than those with low NPAS2 expressions (P=0.0001). CONCLUSION: NPAS2 is down-regulated in CRC and closely correlated with the malignant biological behavior of the tumor and 5-year survival of the patients, suggesting its value in predicting the prognosis of the CRC patients.

[Time interval from the end of sperm processing to artificial intrauterine in semination with husband's sperm correlates to the rate of clinical pregnancy].

OBJECTIVE: To investigate the influence of the time interval from the end of semen processing to artificial intrauterine in semination with husband's sperm (AIH-IUI) on the rate of clinical pregnancy. METHODS: This study involved 191 AIH-IUI cycles with the same ovulation induction protocol. After Percoll density gradient centrifugation, we divided the sperm into four groups based on the incubation time: 0-19, 20-39, 40-59, and 60-80 min, and again into another four groups according to the total progressively motile sperm count (TPMC): (0-9), (10-20), (21-30), and > 30 x 10(6). We analyzed the correlation of the clinical pregnancy rate with the time interval from the end of sperm processing to AIH-IUI and with other influencing factors, such as maternal age, infertility duration, and semen quality. RESULTS: The rate of clinical pregnancy was significantly higher in the 20-39 min group (18.3%) than in the 0-19, 40-59, and 60-80 min groups (12.7, 11.4 and 9.1%) (all P < 0.05). The (10-20) x 10(6) group achieved a remarkably higher pregnancy rate (16.7%) than the (0-9), (21-30), and > 30 x 10(6) groups (0, 11.4, and 8.3%) (all P < 0.05). Logistic multivariate analysis showed that the rate of clinical pregnancy was decreased with the increased age of the women (OR 0.89, 95% CI 0.83-0.94) but significantly elevated in the 20-39 min group (OR 2.11, 95% CI 1.34-3.13) and of (10-20) x 10(6) group (OR 2.06, 95% CI 1.32-3.46). CONCLUSION: The time interval from the end of sperm processing to AIH-IUI is a most significant factor influencing the rate of clinical pregnancy of AIH-IUI.