Mir-21 Expression before and after Chemotherapy in New Cases of Breast Cancer in Women

Abstract Background: Cancer is the second leading cause of death, after cardiovascular diseases worldwide. Breast cancer is the most common known cancer in women with incidence rate of annually 7000 in Iran. MicroRNAs are a group of non-coding RNAs with 20-25 nucleotides length. These molecules play important roles in biological processes such as differentiation, proliferation and apoptosis by post transcriptional regulation of genes. Mir-21 was known as the first microRNA oncogene with the high expression in patients. In this study the level of expression of mir-21 gene was evaluated in new cases of women breast cancer before and after chemotherapy. Materials and Methods: 5 ml of blood was sampled from 40 affected women with age between around 35 to 60 years using of K3-EDTA 6 ml sterile tubes. Plasma was isolated from all blood 40 samples and stored at −80°C.Total RNAs was extracted by RNXplus procedures. PolyA segment was added in 3ˊ region RNA using of poly(A) polymerase enzyme and cDNA was synthesized using of Fermentas kit. In the last stage expression of mir-21 gene was detected via Real-time PCR experiments. Then, the real time data was analyzed by Rest software. Results: Results showed the significant decrease in expression of mir-21 gene after chemotherapy in compare to non-treatment women. Conclusion: By results of this study it can be suggested that chemotherapy causes decrease in mir-21 expression. Therefore, all drugs decreasing the expression of Mir genes could be used as affective way to treatment cancers.

کلیدواژه ها:

Breast cancer ، Women ، MicroRNA ، Mir-21 ، Chemotherapy ، Real time