Micro RNA 34a and Let-7a Expression in Human Breast Cancers is Associated with Apoptotic Expression Genes

  • Behzad, Mansoori (Immunology Research Center, Tabriz University of Medical Sciences) ;
  • Ali, Mohammadi (Immunology Research Center, Tabriz University of Medical Sciences) ;
  • Solmaz, Shirjang (Immunology Research Center, Tabriz University of Medical Sciences) ;
  • Elham, Baghbani (Immunology Research Center, Tabriz University of Medical Sciences) ;
  • Behzad, Baradaran (Immunology Research Center, Tabriz University of Medical Sciences)
  • Published : 2016.06.01


Breast cancer is the most common cause of cancer-related death among women in the whole world. MiR- 34a and let-7a are well known tumor suppressors that participate in the regulation of apoptosis, invasion and other cellular functions. In this study, expression of miR-34a, let-7a and apoptosis pathway genes such as Bcl-2, Caspase-3 and P53 were evaluated using quantitative real-time PCR in 45 paired samples of normal margin and tumor tissue collected from breast cancer patient at advanced stage (3-4). MiR-34a, let-7a, caspase-3 and P53 expression are reduced and Bcl-2 expression is increased within tumoral tissues in comparison with normal margin tissues. P53 expression directly or indirectly was correlated with miR-34a, let-7a, Bcl-2 and caspase-3 expression. In This study we found that MiR-34a and let-7a expression are reduced in the tumoral tissues. Down-regulation of these two molecules correlated with expression of genes associated with apoptosis. These results suggest that due to the correlation of miR-34a and let-7a with apoptotic and anti-apoptotic pathways these molecules could participate as regulators in advanced clinical stages of breast cancer and should be considered as markers for diagnosis, prognostic assessment and targeted therapy.


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