Either restricted or excessive sleep may impair semen quality. Further research is needed to validate this finding.

No abstract

The protein containing the C2 domain has been well documented for its essential roles in endocytosis, cellular metabolism and cancer. Tac2-N (TC2N) is a tandem C2 domain-containing protein, but its function, including its role in tumorigenesis, remains unknown. Here, we first identified TC2N as a novel oncogene in lung cancer. TC2N was preferentially upregulated in lung cancer tissues compared with adjacent normal lung tissues. High TC2N expression was significantly associated with poor outcome of lung cancer patients. Knockdown of TC2N markedly induces cell apoptosis and cell cycle arrest with repressing proliferation in vitro, and suppresses tumorigenicity in vivo, whereas overexpression of TC2N has the opposite effects both in vitro and in vivo. Using a combination of TCGA database and bioinformatics, we demonstrate that TC2N is involved in regulation of the p53 signaling pathway. Mechanistically, TC2N attenuates p53 signaling pathway through inhibiting Cdk5-induced phosphorylation of p53 via inducing Cdk5 degradation or disrupting the interaction between Cdk5 and p53. Moreover, the blockade of p53 attenuates the function of TC2N knockdown in the regulation of cell proliferation and apoptosis. In addition, downregulated TC2N is involved in the apoptosis of lung cancer cells induced by doxorubicin, leading to p53 pathway activation. Overall, these findings uncover a role for the p53 inactivator TC2N in regulating the proliferation and apoptosis of lung cancer cells. Our present study provides novel insights into the mechanism of tumorigenesis in lung cancer.

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Quantification of the association between the intake of cholesterol and risk of pancreatic cancer is still conflicting. We therefore conducted a meta-analysis to summarize the evidence from epidemiological studies of cholesterol intake and the risk of pancreatic cancer. Pertinent studies were delivered by PubMed and Web of Knowledge issued through April of 2014. A random effects model was used to process the data for analysis. Sensitivity analysis and publication bias were conducted. Dose-response relationship was assessed by restricted cubic spline and variance-weighted least squares regression analysis. With 4513 pancreatic cases exemplified, 16 articles were applied in the meta-analysis. Pooled results suggest that cholesterol intake level was significantly associated with the risk of pancreatic cancer [summary relative risk (RR) = 1.371, 95%CI = 1.155–1.627, I2 = 58.2%], especially in America [summary RR = 1.302, 95%CI = 1.090–1.556]. A linear dose-response relation was attested that the risk of pancreatic cancer rises by 8% with 100 mg/day of cholesterol intake. [summary RR = 1.08, 95% CI = 1.04–1.13]. In conclusion, our analysis suggests that a high intake of cholesterol might increase the risk of pancreatic cancer, especially in America.