Breast cancer (BC) is a common malignancy affecting women, with increasing incidences of this disease in China every year. Recent studies have extensively investigated a single nucleotide polymorphism in the let-7 miRNA binding site of the 3'-untranslated region of KRAS mRNA. The aim of this study was to determine the genotype frequency of the KRAS rs712 polymorphism, and evaluate its effect on BC risk. This hospital-based case-control study comprised 228 patients with histologically confirmed BC and 251 healthy controls.
Lung cancer is a complex polygenic disease and many genetic factors are involved in the development of the disease. As one of the most important and widely studied families of microRNA, let-7 appears to play an important role in initiation and progression of lung cancer. Any small changes in miRNA level or its target point can cause significant changes in gene function. In this study, we examined whether a single-nucleotide polymorphism in the promoter region of the let-7 family (rs10877887) is associated with the susceptibility to and prognosis of lung adenocarcinoma cancer.