부산대학교 도서관

Byline: Chun-Wen Cheng (1), Jyh-Cherng Yu (2), Chiun-Sheng Huang (3), Jia-Ching Shieh (4), Yi-Ping Fu (5), Hsiao-Wei Wang (5), Pei-Ei Wu (5), Chen-Yang Shen (5,6) Keywords: Breast cancer; Estrogen; cSHMT; MS; MTHFR; Polymorphism Abstract: Cytosolic serine hydroxymethyltransferase (cSHMT) is key to intersection of folate-metabolic pathway, participating in the pyrimidine synthesis for DNA repair. Based on the hypothesis that variants of the cSHMT C1420T together with methionine synthase (MS A2756G) and 5,10-methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) are associated with breast cancer, we performed a multigenic case--control study of the effects to breast cancer risk of four polymorphisms of folate-metabloizing genes against duration of estrogen exposure. Support of our hypothesis came from the following observations: (i) Allelic frequency of cSHMT C1420T was higher in the controls than in the cases, manifesting a 0.56-fold risk reduction in breast cancer (95%CI = 0.39--0.80) and this association was more significant in those women are susceptible to time of estrogen exposure. (ii) A joint effect of the cSHMT and MS polymorphisms significantly reduced susceptibility to breast cancer (aOR = 0.55 95%CI = 0.34--0.88). (iii) There was a trend toward a reduced risk of breast cancer in women carrying a greater number of putative low-risk genotypes (P .sub.trend= 0.048). (iv) This synergistic effects on risk reduction was significantly interacted with length of estrogen exposure, exhibiting a longer time of estrogen exposure (aY=30 years), menarche-to-FFTP interval (>11 years), age at the first full-term pregnancy (a$?25 years), and body mass index (a$?24). In conclusion, our study provides support to account for the preferential role of cSHMT polymorphism to lower risk of female breast cancer, and such reduced risk would be more significant in carriers with the polymorphisms of MS and MTHFR genes. Author Affiliation: (1) Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung, 402, Taiwan (2) Division of General Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (3) Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan (4) Department of Biomedical Sciences, Chung-Shan Medical University, Taichung, Taiwan (5) Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan (6) Graduate Institute of Environmental Science, China Medical University, Taichung, 40402, Taiwan Article History: Registration Date: 06/09/2007 Received Date: 04/09/2007 Accepted Date: 06/09/2007 Online Date: 22/09/2007