BACKGROUND: To date, results on relationship between CYP3A4 gene polymorphism were limited and inconclusive, and no study focused on the influence of CYP3A4 gene-obesity interaction on breast cancer risk, especially in Chinese women. The purpose of this study was to evaluate the impact of four single nucleotide polymorphisms (SNPs) of CYP3A4 gene, the SNP-SNP and gene-environment interactions on the susceptibility to breast cancer in Chinese women. METHODS: Logistic regression was used to explore the relationship between four SNPs of CYP3A4 gene and the risk of breast cancer. Generalized multifactor dimensionality reduction (GMDR) was used to screen the best SNP-SNP and gene-abdominal obesity interaction combinations among four SNPs and abdominal obesity. Haplotype examination among 4 SNPs was conducted using the SHEsis web-based platform. RESULTS: Logistic regression analysis showed that carriers of rs2242480- T allele have significantly higher breast cancer risk, than those with rs2242480- CC genotype, adjusted OR (95%CI) was 1.68 (1.23-2.16) and 2.03 (1.53-2.58) for participants with CT genotype and TT genotype under additive model. We did not find any notable interactions between the four SNPs within the CYP3A4 gene. GMDR model found a significant association in a two-locus model involving rs2242480 and obesity, with a p-value of 0.018. Stratified analysis found that breast cancer risk was the highest in obese participants with rs2242480- CT or TT genotype, compared to those non-obese participants with rs2242480- CC genotype, OR (95%CI) was 3.02 (1.83-4.25). We found that all haplotype combinations were not correlated with breast cancer risk. CONCLUSIONS We found that the T allele of rs2242480 within the CYP3A4 gene and interaction between rs2242480 and obesity were associated with an increased risk of breast cancer. However, the results of this study were only applicable to the Han ethnic group and cannot be generalized to other ethnic groups in China, and more SNPs of CYP3A4 gene should been enrolled in the analysis in the future, to verify the results obtained in this study.
Adult ; Aged ; Female ; Humans ; Middle Aged ; Breast Neoplasms/etiology* ; China/epidemiology* ; Cytochrome P-450 CYP3A/metabolism* ; Gene-Environment Interaction ; Genetic Predisposition to Disease ; Haplotypes ; Obesity/epidemiology* ; Polymorphism, Single Nucleotide ; Risk Factors ; East Asian People

Objective To investigate the radiosensitiation effect of berberine on human nasopharyngeal carcinoma ( NPC) in hypoxia condition and explore the underlying mechanisms. Methods MTT assay, clonogenic assay and flow cytometry were performed to analyze cell proliferation, colony formation and apoptosis, respectively. Male nude mice inoculated subcutaneously with CNE-2 cells were used to examine the radiosensitization effect of berberine in vivo. The expressions of HIF-1α and VEGF were assessed by Western blot. Results Berberine efficiently inhibited the proliferation of CNE-2 cells in time-dependent and dose-dependent fashions with an IC50 of ( 14?9 ± 2?2 ) μmol/L. Clonogenic survival assay showed that berberine ( 5 μmol/L ) sensitized CNE-2 cells to ionizing radiation in hypoxia and its SERD0 was 1?27. Under hypoxic condition, berberine alone (5, 15 μmol/L) could induce apoptosis (t=5?01, 9?02,P<0?05) and it further promoted 8 Gy radiation-induced apoptosis (t =5?31, 9?91,P <0?05). Moreover, berberine significantly delayed the tumor growth in the combination group (berberine +irradiation) compared with the mice received irradiation alone or PBS (t =2?96, 14?52, P <0?05). Immunobloting assay showed that berberine inhibited the upregulation of HIF-1α and VEGF induced by hypoxia in CNE-2 cells. Conclusion Berberine confers radiosensitivity on hypoxic NPC in vitro and in vivo, which is probably associated with the downregulation of HIF-1α and VEGF expressions.

Objective To explore the radiosensitivity of berberine on esophageal cancer cells under hypoxia condition.Methods MTT assay and clonogenic survival assay were used to evaluate the effect of berberine on proliferation inhibition and radiosensitivity of esophageal cancer cells,respectively.Immunofluorescence was employed to examine the expression of HIF-1.The change of cell cycle distribution and cell apoptosis was assayed by flow cytometry.The expression of HIF-1 was measured by Western blot.DNA damage was detected by γ-H2AX Foci counting.Results With a clear dose and time effect,berberine inhibited cell proliferation and enhanced cell radiosensitivity(t =3.69,P＜0.05)with a sensitizing enhancement ratio(SER)of 1.42.Berberine caused a dose-dependent decrease in HIF-1 protein expression and also significantly increased the cell apoptosis in ECA-109 population(t=4.74,P＜0.05).Compared with the radiation alone group,berberine enhanced X-ray induced DNA double chain breaks(DSB).Conclusions Berberine can increase the radiosensitivity of esophageal cell line ECA-109,which may be associated with decrease of HIF-1 expression and induction of apoptosis in ECA-109 cells.