Document Type : Original Article
Department of Blood Transfusion, The Third Xiangya Hospital of Central South University, Changsha, China
Research and Teaching Department, Changsha Central Hospital, Changsha, Hunan, China
The Third Xiangya Hospital of Central South University, Changsha, China
Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
Objective: The present work was aimed at uncovering the effect of circRNA-011235 (circ-011235) on irradiation-induced
bone mesenchymal stem cells (BMSCs) injury and its regulatory mechanism, with a view to establish a scientific basis for its possible medical applications.
Materials and Methods: In this experimental study, after irradiation with different doses (0, 2, 4, 6 GY), the relative expression levels of circ-011235, miR-741-3p, and cyclin-dependent kinases 6 (CDK6) were detected in the BMSCs, using the real time-quantitative polymerase chain reaction (RT-qPCR). The overexpression effects of circ-011235 and CDK6 on the cell proliferation in irradiation-treated BMSCs were measured by the Cell Counting Kit-8 (CCK8) assay. And also, their effects on the cell cycle were evaluated by flow cytometry. RT-qPCR and immunoblotting were performed to detect the effects of pcDNA-circ-011235 and pcDNA-CDK6 on the expression of cyclin D1 and cyclindependent kinases 4 (CDK4) at the gene and protein levels, respectively.
Results: Irradiation treatment elevated the expression of circ-011235 and CDK6, but reduced miR-741-3p expression in the BMSCs with a dose-dependent effect. The proliferation of BMSCs was significantly inhibited in the irradiation treatment group, while the overexpression of circ-011235 and CDK6 effectively attenuated this inhibition. Also, overexpression of circ-011235 and CDK6 elevated the expression of cyclin D1 in irradiation-treated BMSCs, but had no
significant effect on the CDK4 expression.
Conclusion: Our results demonstrated that circ-011235 up-regulated the expression of cyclin D1 via miR-741-3p/CDK6 signal pathway, thereby promoting cell cycle progression and proliferation of irradiation-treated BMSCs. This finding suggested circ-011235/ miR-741-3p/CDK6 pathway exerted a protective role in the response to irradiation and will be a potential new target for future research on the mechanism involved in the resistance of BMSCs to radiation.