Involvement of IGF-1R regulation by miR-515-5p modifies breast cancer risk among BRCA1 carriers

Abstract

Several lines of evidence indicate that sequence alterations within microRNA (miRNA)-binding sites can modify the binding to its target gene resulting in altered expression patterns. We hypothesized that a single nucleotide polymorphism (SNP) located in the miR-515-5p binding site of igf-1r gene may alter IGF-1R regulation, with consequent effects on breast cancer risk in BRCA1 mutation carriers. Computational prediction revealed that the rs28674628 SNP in the igf-1r 3' UTR is located within a predicted binding site for miR-515-5p. The effect of this SNP on breast cancer risk was evaluated by genotyping 115 Jewish Ashkenazi carriers of the 185delAG mutation in the BRCA1 gene using the Sequenom platform followed by Kaplan-Meier analysis. Additional data set of 378 Jewish BRCA1 carriers was analyzed to validate our results. MiRNA transfection, Western blot analysis, luciferase reporter assay, real time PCR, and immunohistochemistry were performed to assess direct regulation of igf-1r by miR-515-5p. We show direct regulation of IGF-1R by miR-515-5p. We identified that disrupting miR-515-5p and igf-1r 3' UTR binding by SNP may cause elevated IGF-1R protein levels. Interestingly, miR-515-5p is downregulated in tumor tissue compared to its non-neoplastic surrounding tissue while IGF-1R levels are elevated. This igf-1r SNP was found to be significantly associated with age at diagnosis of breast cancer in Jewish Ashkenazi BRCA1 mutation carriers. These findings support the hypothesis that a SNP located in igf-1r gene may alter miRNA regulation of IGF-1R, with a putative effect on BRCA1 penetrance and breast cancer risk.

Integration of mRNA Expression Profile, Copy Number Alterations, and microRNA Expression Levels in Breast Cancer to Improve Grade Definition

“…Among its possible targets, we identified EF3, which, being a Rho-like GTPase, has an important role in many cellular processes (cytoskeletal rearrangements, transcriptional activation, regulation of cell morphology and cell aggregation, cytokinesis, endocytosis and secretion), but also is possibly involved in oncogenic transformation [113]. This gene is a possible target of Hsa-miR-362-5p, a miRNA of the melanoma signature [114], and Hsa-miR-515-5p, already involved in BC development [115]. Hsa-miR-532-5p regulates also interleukin 6 signal transducer (IL6ST), a signal transducer that could be important for interleukin 6 inflammatory role in BC [116]–[117].…”

Insulin-Like Growth Factor 1 Receptor Is a Prognostic Factor in Classical Hodgkin Lymphoma

“…The sections were quenched for endogenous peroxidase with 0.3% hydrogen peroxide, and then boiled in EDTA (1 mmol/L; pH8.0) for 15 minutes in a microwave oven for antigen retrieval. The sections were incubated at 37°C for 1 hour with the first antibody, IGF-1R (1∶1000, (3C8B1, 3G5C1 [21], [22]), Abcam, Cambridge, UK) pIGF-1R (Y1161, Abcam) and CD30 (BerH2, Dako, Glostrup, Denmark), and 30 minutes with horse-radish peroxidase-labeled secondary and tertiary antibodies (Dako). 3,3′-diaminobenzidine (DAB) chromogen (Sigma Aldrich, St Louis, MO, USA) was used as substrate and sections were counterstained with hematoxylin.…”

MicroRNAs in Disease

“…Nevertheless, miRSNPs are proven to have an emerging role in cancer prognosis. A polymorphism on the 3′ UTR of IGF-1R gene limited the binding of miR-515-5p and increased the risk of developing breast cancer in subjects with BRCA1 mutation [ 59 ]. In addition, increased susceptibility to breast cancer was attributed to two more SNPs identifi ed on TGFB1 and XRCC1 which alter their expression levels as the target site of miR-187 and miR-183 is respectively interrupted [ 60 ].…”