Objective To investigate the expression of Pin1 protein in HepG2 cells under endoplasmic reticulum stress (ERS) and its effect on cell proliferation and apoptosis. Methods The THLE3 cells were treated with tunicamycin (TM) (TM group) or DMSO (DMSO group) for 48h. The HepG2 cells were treated with TM (TM group), ATRA(ATRA group), TM+ATRA (TM+ATRA group) or DMSO (DMSO group) for 48h. The protein levels of Bip and Pin1 were detected by Western blot, cell proliferation was detected by CCK-8 assay, and cell apoptosis was detected by flow cytometry. Results The expression of Bip both increased in THLE3 and HepG2 cells treated with TM, indicated that TM effectively induced ERS in cells. Compared with the DMSO group, the protein level of Pin1 in THLE3 cells in TM group was decreased with the increasing of TM concentration (P < 0.001). In TM+ATRA group, with the increasing of TM concentration, the expression of Pin1 was decreased in HepG2 cells (P < 0.01). The inhibitory rates was (29.33±4.73)% in HepG2 cells in TM group, significantly lower than (60.33±2.08)% in THLE3 cells in TM group (P < 0.001). In TM+ATRA group, the growth inhibition rates was increased to (60.33±6.03)% in HepG2 cells. The apoptosis rate of THLE3 cells in TM group was (22.25±0.78)%, significantly higher than (3.57±0.31)% in DMSO group (P < 0.01). The apoptosis rates of HepG2 cells in ATRA group and TM+ATRA group were significantly higher than that in the DMSO group ((10.03±0.49)% vs. (5.10±1.00)%, P < 0.05 and (23.70±0.75)% vs. (5.10±1.00)%, P < 0.01). Conclusions HepG2 cells resist ERS-induced apoptosis by maintaining Pin1 protein level. Reducing the protein level of Pin1 can significantly inhibit the cell proliferation and induce apoptosis.

Objective:Using Meta-analysis to evaluate the association between Pin1 gene polymorphism at -842 loci and cancer susceptibility.Methods:Pin1, polymorphism, tumor, variant and cancer as key words were used to systematically search for the case-control research on the association between the -842G/C polymorphisms of Pin1 and cancer susceptibility through China National Knowledge Infrastructure (CNKI), Wanfang Data, Embase and PubMed. The time of literatures was up to April 2 nd, 2019. Heterogeneity test, combined risk of cancer with the -842 C allele of Pin1, publication bias test and sensitivity analysis were performed by using Stata 12.0 software. Results:A total of 144 articles were retrieved. According to the inclusion criteria, a total of 11 articles were included (2 Chinese documents and 9 English documents). There were 5 667 cases and 6 120 controls in eligible articles. The heterozygous model showed that Pin1 (-842G/C) polymorphism was associated with cancer susceptibility, and the pooled OR (95 %CI) value was 0.78 (0.61, 0.99). Subgroup analysis by cancer type suggested that the Pin1 (-842G/C) polymorphism could significantly decrease the incidence of breast cancer and lung cancer under the heterozygous model (GC vs GG), dominant model (GC+CC vs GG) and allele model (C vs G). The pooled OR (95 %CI) values were 0.73 (0.58, 0.92), 0.71 (0.57, 0.89), and 0.73 (0.60, 0.89) in breast cancer and 0.64 (0.52, 0.78), 0.64 (0.53, 0.78), and 0.67 (0.55, 0.80) in lung cancer. The variant -842 C allele could significantly increase the risk of nasopharyngeal carcinoma under the homozygote model (CC vs GG) and recessive model (CC vs GG+GC). The pooled OR (95 %CI) values were 2.22 (1.03-4.75) and 2.47 (1.16-5.26). No significant association was observed in squamous cell carcinoma. Conclusion:This Meta-analysis demonstrated that Pin1gene polymorphism at -842 was associated with cancer susceptibility.

Objective:Using Meta-analysis to evaluate the association between Pin1 gene polymorphism at -842 loci and cancer susceptibility.Methods:Pin1, polymorphism, tumor, variant and cancer as key words were used to systematically search for the case-control research on the association between the -842G/C polymorphisms of Pin1 and cancer susceptibility through China National Knowledge Infrastructure (CNKI), Wanfang Data, Embase and PubMed. The time of literatures was up to April 2 nd, 2019. Heterogeneity test, combined risk of cancer with the -842 C allele of Pin1, publication bias test and sensitivity analysis were performed by using Stata 12.0 software. Results:A total of 144 articles were retrieved. According to the inclusion criteria, a total of 11 articles were included (2 Chinese documents and 9 English documents). There were 5 667 cases and 6 120 controls in eligible articles. The heterozygous model showed that Pin1 (-842G/C) polymorphism was associated with cancer susceptibility, and the pooled OR (95 %CI) value was 0.78 (0.61, 0.99). Subgroup analysis by cancer type suggested that the Pin1 (-842G/C) polymorphism could significantly decrease the incidence of breast cancer and lung cancer under the heterozygous model (GC vs GG), dominant model (GC+CC vs GG) and allele model (C vs G). The pooled OR (95 %CI) values were 0.73 (0.58, 0.92), 0.71 (0.57, 0.89), and 0.73 (0.60, 0.89) in breast cancer and 0.64 (0.52, 0.78), 0.64 (0.53, 0.78), and 0.67 (0.55, 0.80) in lung cancer. The variant -842 C allele could significantly increase the risk of nasopharyngeal carcinoma under the homozygote model (CC vs GG) and recessive model (CC vs GG+GC). The pooled OR (95 %CI) values were 2.22 (1.03-4.75) and 2.47 (1.16-5.26). No significant association was observed in squamous cell carcinoma. Conclusion:This Meta-analysis demonstrated that Pin1gene polymorphism at -842 was associated with cancer susceptibility.