eng Science and Education Publishing Journal of Cancer Research and Treatment 2374-2003 2019-07-16 7 1 10 16 10.12691/jcrt-7-1-2 JCRT2019712 article Shaymaa E. El Feky shaymaa.elfeky@alexu.edu.eg 1 Fawziya A.R. Ibrahim 2 Adel Nassar 3 Nadia A. Abd El Moneim 4 Samia A. Ebeid 4 Mohammad A. Ahmad 5 Sanaa Shawky 6 Mohammad M. Nasef 6 Radiation Sciences Department, Medical Research Institute, Alexandria University, Alexandria, Egypt Applied Medical Chemistry Department, Medical Research Institute, Alexandria University, Alexandria, Egypt Chemistry Department, Faculty of Science, Menoufia University, Shebin El-Koam, Egypt Cancer Management and Research Department, Medical Research Institute, University of Alexandria, Egypt Military Medical Academy, Alexandria, Egypt Pathology Department, Medical Research Institute, University of Alexandria, Egypt Triple negative is a subtype of breast cancer characterized by lack of expression of hormone receptors (ER, PR and Her2/neu). Due to the limited treatment options, the search for novel treatment targets continues. The aim of this study was to assess the differential expression of miR-206, VEGF and KRAS in TNBC and non-TNBC tissues and cell lines and to evaluate the modulatory effect of miR-206 on the key oncogenic targets VEGF and KRAS. The expression of miR-206, VEGF and KRAS was quantified using real time PCR in both paraffin embedded breast cancer and adjacent tissues as well as in MDA-MB-231 and MCF-7 cell lines. Cell lines were transfected with different concentrations of miR-206 mimic and their viability were assessed using MTT assay. Our results indicated that miR-206 was significantly downregulated in cancerous compared to non-cancerous tissues with a more pronounced downregulation in TNBC than non-TNBC tissues. VEGF and KRAS were significantly upregulated in TNBC compared to non-TNBC and their expression was negatively correlated to miR-206 expression. Transfection of TNBC and non-TNBC cell lines with miR-206 mimic resulted in a dose dependent reduction in cell viability as well as a significant reduction in VEGF and KRAS expression. In conclusion, based on our combined human tissues and cell line-based investigations we can suggest that VEGF and KRAS may be potential targets for miR-206-mediated regulation and that their targeting by miR-206 can be a highly efficient therapeutic strategy in TNBC. http://pubs.sciepub.com/jcrt/7/1/2/jcrt-7-1-2.pdf triple negative breast cancer miR-206 VEGF KRAS epigenetic regulation