The Effects Of Small Interfering RNA Silencing SLC7A5 Gene On Biologic Characteristics In SKM-1 Cell Line

Background:We established A nested case-control study cohort in 435 primary and untreated myelodysplastic syndrome (MDS) patients in order to investigate the clinical characteristics, WHO subtype and risk factors associated with MDS evolution to leukemia of this cohort.52 patients (12%) was lost until the end of follow-up. The mean follow-up period was 20.3(4.2-57.1) months. In the rest of 383 patients followed, the case group was patients with progressing to acute leukemia by the end of follow-up, while the control group was patients without transformation by that time. The case group included 41 patients and the control group included 342 patients. The gene expression profile of patients in the case group at diagnosis and after transformation was analyzed as self-control study. Besides, we compared the gene expression profile of paired patients at diagnosis as case-control study. Subsequently we picked up a subset of 6 genes to distinguish the case group and the control group stably. They are TUBB.PSMD1、SLC7A5、ATG3、TUBB2C and TIMM10. Our group members have already analyzed TUBB、PSMD1 and ATG3 genes. So this time SLC7A5 gene is chosen to further study.Objective:To investigate the effect of small interfering RNA (siRNA) against SLC7A5 gene on SKM-1 cell line and SLC7A5 gene on myelodysplastic syndrome to leukemic transformation.Methods:SLC7A5 gene specific siRNA (SLC7A5-siRNA) was synthesized chemically. SLC7A5-siRNA was transfected by LipofectamineTM 2000 for delivery into SKM-1 cell line. It’s a malignant cell line established in the MDS leukemic phase. Cells were harvested after 24 hours of transfection. After figuring out the transfection efficiency and SLC7A5 gene expression by Realtime PCR in each group, SKM-1 cells were observe and compared the changes on growth curve, cell cycle, apoptosis and morphological features under the electron microscope.Result:Compared with the negative control group, the proliferation of SLC7A5-siRNA group was inhibited. The cell cycle analysis by flow cytometer illustrated the increase of G0/G1 phase cells and the reduction of S phase cells in SLC7A5-siRNA group. It was suggested that cells of SLC7A5-siRNA group were obstructed at G0/G1 phase. Apoptosis analysis of the SKM-1 cells by flow cytometer showedd that proportions of early apoptosis and late apoptosis were both increased. More apoptotic cells can be observed in SLC7A5-siRNA group under the electron microscope.Conclusion:The growth and colony formation of the SKM-1 cell lines were inhibited by silencing SLC7A5 gene. It showed an increasing tendency to apoptosis and death. In summary, the malignancy of SKM-1 cell lines were decreased after transfection. It is suggested that SLC7A5 gene may play an important role in transformation of MDS.