Abstract
BACKGROUND The expression of miR-205 is closely related to the occurrence, development, and prognosis of lung cancer and breast cancer. However, studies show that it plays opposite roles in different tumor types. Because the expression and regulation of miR-205 are primarily confined to epigenetic areas, whether genetic variation of miR-205 is related to the occurrence or to the development of tumors has not been reported. The aim of this study was to screen genetic variation of miR-205 gene and to investigate its association with the risk and development of lung and breast cancer. MATERIAL AND METHODS Genomic DNA was extracted from cultured tumor cell lines and formalin-fixed and paraffin-embedded lung and breast tissue samples. Bisulfite Clone Sequencing (BCS) and qRT-PCR were employed to detect the DNA methylation status and gene expression of the miR-205 gene, respectively. Genetic variation of miR-205 and miR-205HG were genotyped with PCR-sequencing method. Immunohistochemical analysis for ER, PR, and HER2 was performed on breast tissue samples. RESULTS These results indicate that the functional association of rs3842530 in miR-205HG and lung cancer might provide a possible explanation for the tissue-dependent function of miR-205 in different tumors. CONCLUSIONS These results indicate that the functional association of rs3842530 in miR-205HG and lung cancer might provide a possible explanation for the tissue-dependent function of miR-205 in different tumors.