SPINK2 Silence Inhibited Tumor Growth By Reducing The Self-renewal Of Acute Leukemia Cell Line KG-1a

Objective:Leukemia stem cells play an important role in the progression of leukemia.SPINK2,a member of the Kazal-type family of serine protease inhibitors,is associated with sperm differentiation,testicular cancer,and lymphoma progression.Currently,SPINK2 expression has been found up-regulated in acute leukemia and is associated with patient prognosis,but the specific role and mechanism remains unclear.Methods:In this study,we performed experiments using bioinformatics and KG-1a cells,including si RNA-mediated gene silencing,flow cytometric sorting of leukemia cell line stem cells,CCK8 and Nude mouse subcutaneous tumorigenesis experiment to detect cell viability,and Annexin VPI staining to detect Cell apoptosis,PI single staining to detect cell cycle,Transwell assay to detect cell invasive ability,Tumor Sphere Formation experiment to detect cell stemness and Western blot assay to detect related protein expression levels.We compare the changes of KG-1a cell viability and protein level before and after SPINK2 silencing to explore the role and mechanism of SPINK2 in AML.Result:High levels of SPINK2 expression in AML cells have been found to be associated with poor overall survival and prognosis of AML in open data.Furthermore,high expression of SPINK2 gene is confirmed in leukemia stem cells.Si RNA-mediated down-regulation of SPINK2 expression in KG1 a cells resulted in growth restriction,Cell cycle arrest in G1 phase,and reduced invasiveness.Silenced SPINK2 by RNAi technology,which inhibited cell proliferation signals.SPINK2 gene silencing in CD34-CD38+ KG1 a cell reduced the Tumor Sphere Formation efficiency in vitro.Treatment of AML cells with SPINK2 silencing combined with cytarabine showed enhanced anti-leukemic activity.After SPINK2 silenced,Hippo pathway was upregulated,meanwhile,inhibited with Verteporfin,YAP protein phosphorylation increased and KG-1a cells resumed proliferative activity.Conclusion:In brief,it is possible to inhibit the proliferation of leukemic stem cells by silencing SPINK2 and increase their sensitivity to chemotherapy,which providing a new potential therapeutic target for AML.