Breast cancer

effects of protumoral dietary patterns on oncogenic and oncosuppressive microRNA expression

Abstract

MicroRNAs or miRs, Oncogenic (OncomiR) and Oncosuppressive, participate in the regulation of gene expression and present a particular deregulation in different types of cancer. Given that dietary habits would have a role in the occurrence of cancer, the interest arises to study the effect of protumoral dietary patterns on the expression of miRs commonly deregulated in a characteristic way in breast cancer.

We investigated the influence of the dietary components fructose (F), palmitic acid (PA) and mixture (F+PA) on miRs expression in cultured MCF7 breast cancer cells and Carcinoma Associated Fibroblasts F88 (CAF-F88) and miRs expression was analyzed in a murine model of breast cancer in the context of high fructose (PBA), high fat (PCS) and a mixture of both (PBA+PCS) diets.  Extraction of miRs from culture and serum samples was performed and expression levels were determined by retrotranscription and quantitative polymerase chain reaction (RTqPCR) using the Taqman primer and probe system specific for the OncomiRs miR 21 and miR 155 and the miR Oncosuppressor miRs miR let7a and miR 195.

In MCF7 cells, miRs expression was mainly affected by F+AP treatment. In CAF-F88 cells, overexpression of OncomiRs was observed with AP treatment and a decrease in OncoSuppressor miRs with F+AP treatment. In serum from the murine experimental model, a significant increase of the OncomiR miR21 and a decrease of the Oncosuppressor miR-Let7a were observed in the group treated with the PBA+PCS diet.

The observed modifications in the expression of miRs commonly deregulated in breast cancer demonstrate the involvement of miRs as one of the underlying regulatory molecular mechanisms that would favor the development of tumor processes and their proliferation in nutritional contexts and protumor diets.