%0 Journal Article
%T KRAS rs61764370 is associated with HER2-overexpressed and poorly-differentiated breast cancer in hormone replacement therapy users: a case control study
%A Jasmina-Ziva Cerne
%A Vida Stegel
%A Ksenija Gersak
%A Srdjan Novakovic
%J BMC Cancer
%D 2012
%I BioMed Central
%R 10.1186/1471-2407-12-105
%X Genotyping was accomplished in 530 sporadic postmenopausal breast cancer cases, 165 familial breast cancer cases (including N = 29, who test positive for BRCA1/2 mutations) and 270 postmenopausal control women using the flurogenic 5' nuclease assay. Information on hormone replacement therapy (HRT) use and tumor characteristics in sporadic breast cancer cases was ascertained from a postal questionnaire and pathology reports, respectively. Associations between the KRAS genotype and breast cancer or breast tumor characteristics were assessed using chi-square test and logistic regression models.No evidence of association was observed between the KRAS variant and risk of sporadic and familial breast cancer - either among BRCA carriers or non-BRCA carriers. The KRAS variant was statistically significantly more often associated with human epidermal growth factor receptor 2 (HER2) - positive tumors and tumors of higher histopathologic grade. However, both associations were detected only in HRT users.Our data do not support the hypothesis that the KRAS variant rs61764370 is implicated in the aetiology of sporadic or of familial breast cancer. In postmenopausal women using HRT, the KRAS variant might lead to HER2 overexpressed and poorly-differentiated breast tumors, both indicators of a worse prognosis.MicroRNAs (miRNAs) are a class of small non-coding RNAs that function as negative gene regulators. Depending on the degree of complementarity between the miRNA and its target mRNA, miRNAs post-transcriptionally regulate target gene expression by either inhibiting mRNA translation or inducing mRNA degradation [1]. Recent evidence has shown that impaired miRNA expression or single nucleotide polymorphisms (SNPs) that reside on miRNAs and/or miRNA-binding sites correlate with various human cancers [2]. Depending on target mRNAs, miRNAs can function as tumor suppressors or oncogenes [3].The let-7 family of miRNAs plays an important role in tumorigenesis by regulating the expressio
%K KRAS rs61764370
%K Breast cancer
%K Tumor characteristics
%K Hormone replacement therapy
%U http://www.biomedcentral.com/1471-2407/12/105