SALL4: A Potential Therapeutic Target Site Of Acute Myeloid Leukaemia

Objective:To construct an efficient SALL4 shRNA vector and transfect it into THP-1 cells for investigating the effect of SALL4 in leukemia.Methods:To design four SALL4-specific siRNAs to aim at different SALL4 mRNA target sites and a negative control siRNA,construct pGPU6/GFP/Neo/SALL4 shRNA vectors. Tansfect them into THP-1 cells and detect the expression of SALL4 in shRNAs,blank control and negative control.Result:The results of real time quantitive PCR and western blot both exhibited that the interferance effect of pGPU6/GFP/Neo/SALL4 shRNA-B vector was optimal, which aimed at mRNA-1122 target site and down-regulated the expression of SALL4 most.Conclusion:Successfully construct SALL4 siRNA vector. We can choose SALL4 shRNA-B to complete the research of SALL4. Objective To investigate the biological behaviour of THP-1 cells changed by SALL4 RNA interference. Methods To construct a SALL4-specific shRNA vector and transfect it into THP-1 cells. To detect the difference of cell proliferation by MTT among blank control,SALL4 shRNA group and negative control; cell apoptosis and cell cycle by flow cytometry. Result The cell proliferation of THP-1 cells tansfected by SALL4 shRNA were lower than blank control and negative control obviously. Cell apoptosis of shRNA group was higher than control while M stage cell proportion was lower. Conclusion The tumor cell characteristic of THP-1 cells was inhibited by SALL4 RNA interference obviously. SALL4 may play an important role to maintain the tumor cell characteristic of THP-1 cells and be an oncogene of leukemia. Objective:To investigate the change of SALL4 mRNA expression of THP-1 cells interfered with chemotherapeutic drugs and the effects of SALL4 in mechanism of chemotherapeutic drugs killing leukemia cells. Methods:MTT and improved Korber's methods were used to calculate the 50%inhibiting concentration(IC50) of Ara-C and DNR in vitro respectively. THP-1 cells were interfered with IC50 concentration drugs, and then expression of SALL4 mRNA was detected by real time PCR. Results:Expression of SALL4 mRNA could be decreased by Ara-C and DNR intervention respectively, and with the time of drug action extending, the inhibitory intensity increased. Conclusions:SALL4 may be one of the target sites through which Ara-C and DNR could kill THP-1 cells. Objective:To investigate the relationship between SALL4 and oncogene survivin, anti-oncogene PTEN and identify whether survivin and PTEN are the downstream effectors of SALL4. Methods:RNA interference was used to knock-down the expression of SALL4.The expression of survivin and PTEN was detected by real time PCR and western blot subsequently. Results:The expression of survivin was down-regulated when SALL4 was suppressed simultaneously, while the expression of PTEN increased. But the same effect was observed in the negative control vector. Conclusion:PTEN and survivin may be regulated by changes of SALL4 expression. However,whether they were the SALL4 downstream gene remained for further clarification.