Objective To comprehensively evaluate the association between TNF-α gene −308 G/A polymorphism and the risk of prostate cancer. Methods A meta-analysis was performed to analyze the association between −308 G/A polymorphism and the risk of prostate cancer risk. Results A total of 11 case-control studies (4 919 cases and 5 210 controls) were included in this meta-analysis. The result showed no statistically significant differences in all genotype distribution between prostate cancer cases and controls: dominant model (OR=1.11, 95%CI 0.90 to 1.36, P=0.33), recessive model (OR=0.91, 95%CI 0.70 to 1.18, P=0.47), GA versus GG (OR=1.11, 95%CI 0.90 to 1.37, P=0.33), AA versus GG (OR=0.92, 95%CI 0.71 to 1.20, P=0.55), A versus G (OR=1.07, 95%CI 0.91 to 1.26, P=0.39). In the subgroup analysis by ethnicity, no statistically differences were found between prostate cancer cases and controls. Conclusion This results of meta-analysis suggests that TNF-α gene –308G/A polymorphism may not be a risk factor of prostate cancer. Due to the limited quantity of the includied studies, further studies are needed to validate the above conclusion.
Objective To explore the effect of hydrostatic pressure on intracellular free calcium concentration ([Ca2+]i) and the gene expression of transient receptor potential vanilloid (TRPV) in cultured human bladder smooth muscle cells (hb-SMCs), and to prel iminarily probe into the possible molecular mechanism of hb-SMCs prol iferation stimulated by hydrostatic pressure. Methods The passage 6-7 hb-SMCs were loaded with Ca2+ indicator Fluo-3/AM. When the hb-SMCs were under 0 cm H2O (1 cm H2O=0.098 kPa) (group A) or 200 cm H2O hydrostatic pressure for 30 minutes (group B) and then removing the 200 cm H2O hydrostatic pressure (group C), the [Ca2+]i was measured respectively by inverted laser anningconfocal microscope. When the hb-SMCs were given the 200 cm H2O hydrostatic pressure for 0 hour, 2 hours, 6 hours, 2 hours, and 24 hours, the mRNA expressions of TRPV1, TRPV2, and TRPV4 were detected by RT-PCR technique. Results The [Ca2+]i of group A, group B, and group C were (100.808 ± 1.724), (122.008 ± 1.575), and (99.918 ± 0.887) U, respectively; group B was significantly higher than groups A and C (P lt; 0.001). The [Ca2+]i of group C decreased to the base l ine level of group A after removing the pressure (t=0.919, P=0.394). The TRPV1, TRPV2, and TRPV4 genes expressed in hb-SMCs under 200 cm H2O hydrostatic pressure at 0 hour, 2 hours, 6 hours, 12 hours, and 24 hours, but the expressions had no obvious changes with time. There was no significant difference in the expressions of TRPV1, TRPV2, and TRPV4 among 3 groups (P gt; 0.05). Conclusion The [Ca2+]i of hb-SMCs increases significantly under high hydrostatic pressure. As possible genes in stretch-activated cation channel, the TRPV1, TRPV2, and TRPV4 express in hb-SMCs under 200 cm H2O hydrostatic pressure. It is possible that the mechanical pressure regulates the [Ca2+]i of hb-SMCs by opening the stretch-activated cation channel rather than up-regulating its expression.