Expression Patterns of miR181a and miR30d in Patients with Breast Cancer

One of the important molecular pathways in breast cancer is the PTEN-PI3K-AKT pathway. Any change in the activity of the PTEN gene can alter the PI3K-AKT pathway. Moreover, there are subsets of genes and pathways their expression changes by post-transcriptional regulations. For instance, gene regulation alters by non-coding RNAs such as micro-RNAs as post-transcriptional regulators that prevent the expression of the target transcript. Therefore, it is essential to assess the related alterations in micro-RNA expression patterns to find out the possible causes of conversions in related transcripts and pathways such as the PTEN-PI3K-AKT pathway in breast cancer.

To determine the expression level of miR-181a and miR-30d in 30 breast tumor samples and 30 adjacent normal samples, the RNA extraction, and cDNA synthesis was performed by RiboEx (GeneAll, Korea). Finally, the Real-Time PCR method was used for quantitative analysis of the expression levels of these miRNAs. all the experimental part of the project in done at Islamic Azad University in 2017.

After analyzing comparisons in the expression level of miR-181a and miR-30d in tumor and normal tissues, there was a significant increase in the expression level of miR-181a in tumor samples compared with normal samples. Moreover, the expression level of miR-30d in tumor samples reported a significant decrease in comparison with normal samples (P<0.05).

Upregulation of miR-181a may affect the transcription of the PTEN gene resulting in the cell progress to cancer. The Downregulation of miR-30d may also lead to cancer cell growth, due to a reduction in the affecting on the CREB gene transcript.