Evaluation of the effect of chemical hypoxia on proliferation, the expression of miR-27a, miR-370, miR-9 and their target genes in MOLT-4 and KG1 cell lines

Abstract

That is now clear the specific physiological conditions of a tumor environment such as hypoxia are extremely important in the development of cancer. An increase in the HIF1 alpha level contributes to the an effect on the expression of miRNAs and target genes consequently hypoxia impacts on genes involved in drug and radio therapy resistance, apoptosis and proliferation of tumor cells. Therefore in this study we decided to investigate the effect of hypoxia on proliferation, the expression of miR-27a, miR370, miR-9 and their target genes in MOLT-4 and KG1 cell lines.Materials and Methods: The KG1 and MOLT-4 cell lines were cultured in RPMI 1640 medium supplemented with 20% FBS and 10% FBS respectively. Then, with the use of MTT test optimum and non-cytotoxic dose of CoCl2 for KG1 and MOLT-4 cell lines was calculated. Total RNA was extracted with using trizol according to the manufacturer's protocol. The expression of miR-9, miR370, miR27a and PUMA, BCL-xl, FOXM1, MDR1 and MRP1 gene were evaluated with Real Time PCR.Results: Based on the results, hypoxia induced by CoCl2 was able to regulate the sensitivity of MOLT-4 and KG1 cell lines to chemotherapy agents by increasing the expression of MDR1, MRP1, FOXM1, BCL-xl genes and reducing the expression of PUMA gene compared to the control group. The results also showed that hypoxia condition increases the expression of miR-9 and decreases the expression of miR-27a and miR-370. Therefore hypoxia also impacts on the sensitivity of leukemia cell lines through regulating miRNA expression profile. In concern with the effect of hypoxia on proliferation our outcomes demonstrated that hypoxia induced by CoCl2 has an inhibitory effect on proliferation of MOLT-4 and KG1 cell lines.