Abstract:

Objective To investigate the influence of restoration of oncogenic microRNA-21 (miR-21) in CD44 mRNA and   protein expressions,one of the most common cancer stem cell (CSC) markers,in human gastric cancer Kato Ⅲ cells,and to  provide a new theoretical foundation for research on gastric cancer.Methods Human
gastric cancer Kato Ⅲ cells were cultured and divided into blank control group,Kato Ⅲ/miR-21 group and Kato Ⅲ/control group.Hsa-miR-21 mimics and  hsa-miR-21 control were transfected into Kato Ⅲ cells in Kato Ⅲ/miR-21 group and Kato Ⅲ/control group.Then the expressions of CD44 mRNA and protein in the abovecells were detected by  RT-PCR and Western blotting method.Results The relative expression levels of miR-21 in Kato Ⅲ/miR-21 cells was 1.000 00±0.107 41,which was significantly increased compared with Kato Ⅲ/control cells (0.109 91±0.013 99),there was significant difference( P<0.01). The mRNA level of CD44 in Kato /miR-21 cells was 2.342 23±0.223 47,which was significantly  increased compared with Kato Ⅲ/control cells (0.674 58±0.064 53),there was significant difference(P<0.01).The protein level of CD44 in Kato Ⅲ/miR-21 cells was 0.176 048±0.009 900,which was also significantly increased as compared with Kato Ⅲ/control cells (0.045 929±0.007 396),there was significant difference (P<0.01).Conclusion Restoration of miR-21 expression level can induce the over-xpressions of CD44 mRNA and protein in gastric cancer Kato Ⅲ cells,and may induce the transformation of gastric cancer CSCs.

Key words: microRNA-21, CD44, stomach neoplasms, cancer stem cells