Investigating FGFR2 and B7-H4 gene polymorphisms and their effects in breast cancer

Breast cancer is one of the problems needed to be solved in women health. In our country ¼ of cancers in women is breast cancer.FGFR2 is a member of the FGFR family of RTKs. FGF-receptors play an important role in the control of diverse cellular processes including cell proliferation, differentiation, migration, and maintenance of cellular homeostasis. FGFR2 is amplified and overexpressed in breast cancer. Abnormal expression of FGFR2 alternatively spliced isoforms transforms breast cancer cells by signal transduction. In recent years, some publications have reported the role of FGFR2 polymorphism in breast cancer risk. The association is restricted to SNPs in the linkage disequilibrium (LD) block covering intron 2 and three polymorphic variants (rs1219648, rs2420946, and rs2981582) have been the research focus in scientific community. Some of the studies performed showed that these three polymorphisms were risk factors for developing breast cancer risk, whereas the others showed no such association.B7-H4 is a recently identified member of B7 family which provides co?inhibitor for T cell activation, restricts T cell proliferation, cytokine secretion and cytotoxicity development. B7-H4 is reported to be highly expressed in almost all breast ductal and lobular carcinomas. High levels of B7-H4 overexpression seems to occur early in breast carcinogenesis. In a study performed, three polymorphisms (rs10754339, rs10801935 ve rs3738414) in UTRs and intron 1 of B7-H4 gene were detected and in the northeast of China in Chinese Han population, an association was detected between B7-H4 polymorphisms and breast cancer risk.In our study, FGFR2 gene rs1219648, rs2981582 SNPs were studied by sequence analysis and B7-H4 gene rs10754339, rs10801935 ve rs3738414 SNPs were studied by PCR-RFLP method in 31 women with breast cancer and in the control group including 30 women without cancer diagnosis in the similar age interval and association betweeen these SNPs and breast cancer were aimed to be evaluated.Although statistically not important, the frequency of FGFR2 heterozygous polymorphisms in the group with breast cancer were detected to be higher; B7-H4 rs10801935 polymorphism AA and AG genotype distributions were found in higher frequencies in the group with breast cancer. In contrast to the results of the previous study, in our study B7-H4 rs3738414 polymorphism GG genotype was found to be in higher frequency in the control group than the case group and the result was statistically significant.In order to verify our results, new studies about this subject in Turkish population are needed to be performed.