Expression Of CD44 Splice Variant In Gastric Cancer And Effect Of Parvovirus H-1 Non-Structural Protein NS1 On Expression Of CD44 Splice Variant In Gastric Cancer Cells

Background:Gastric cancer is a common malignant tumor of the digestive system.In 2012,the incidence and mortality of gastric cancer in China were 31.28/100,000 and 22.04/100,000 respectively,but the 5-year survival rate of gastric cancer was less than 30%.CD44 is closely related to the development of gastric cancer,and the non-structural protein 1(NS1)with anti-tumor effect can inhibit the proliferation of gastric cancer cells.CD44 is a surface marker for cancer stem cells.CD44 transcript variant(CD44v)is involved in the whole process of tumorigenesis,such as its formation,metastasis and recurrence.Objective:The expression of CD44v in gastric cancer tissues and gastric cancer cells before and after transfection of NS1 was observed.The relationship between the expression of CD44v and the clinicopathological features of gastric cancer was analyzed,and the effect of NS1 on the expression of CD44v in gastric cancer cell lines was studied.Methods:1.Collected 21 cases of gastric cancer specimens and 7 healthy gastric tissues treated by radical gastrectomy in the Eastern War Zone General Hospital from June to November 2018.The expression of CD44v in gastric cancer tissues was detected by qRT-PCR..2.The pEGFP-N1-Flag-NS1 recombinant plasmid was transfected into gastric cancer cells by liposome method,and the absorbance was measured by MTT,and the growth curve was drawn.qRT-PCR was used to detect the change of CD44v expression in cells before and after transfection.Results:1.The expression levels of CD44v3(t=26,P=0.01),CD44v4(t=37,P=0.05),CD44v6(t=35,P=0.04),CD44v9(t=29,P=0.02)and CD44v10(t=16,P=0.01)in gastric cancer tissues were significantly different from those in normal tissues.2.The expression of CD44v5 is mainly in gastric cancer tissues.3.CD44v3 was correlated with tumor size(?~2=4.95,P=0.05),vascular invasion(?~2=7.88,P=0.02)and nerve invasion(?~2=6.11,P=0.02).CD44v4 was associated with tumor size(?~2=7.46,P=0.02)and vessel invasion(?~2=5.45,P=0.03).The expression of CD44v6 was related to vascular invasion(?~2=10.52,P=0.01)and nerve invasion(?~2=8.24,P=0.01).CD44v8 was associated with tumor size(?~2=10.10,P=0.01),vascular invasion(?~2=7.88,P=0.02)and nerve invasion(?~2=6.11,P=0.02).CD44v9 was correlated with tumor size(?~2=7.46,P=0.02),vessel invasion(?~2=10.52,P=0.01),and nerve invasion(?~2=8.24,P=0.01).The expression of CD44v10 was correlated with tumor size(?~2=4.89,P=0.05)and nerve invasion(?~2=7.22,P=0.01).4.NS1 has an inhibitory effect on gastric cancer cells AGS.NS1 inhibits the proliferation of CD44(+)gastric cancer cells and decreases the expression of CD44v.Conclusion:1.The expression of CD44v3,v4,v6,v8,v9 and v10 is of great significance for the diagnosis and treatment of gastric cancer.2.NS1 inhibits the proliferation of CD44(+)gastric cancer is related to the decrease of the expression of CD44v,especially CD44v5.