Lipopolysaccharide (LPS) Increase The Invasive Ability Of Pancreatic Cancer Cells By Inhibiting The Expression Of Protein Phosphatase2A Catalytic Subunit

Objective:Inflammatory microenviroment plays a multifaceted role in pancreatic cancerprogression. Some investigations found that inflammation stimulus can inhibit theexpression of the Protein Phosphatase2A catalytic subunit (PP2Ac), which is consideredto be a cancer suppressor. In the present study, we used LPS as the inflammation stimulusto investigate the effect of inflammation on the expression of PP2Ac in pancreatic cancercells. Furthermore, we studied whether the change in PP2Ac expression could affect theinvasive ability of panceatic cancer cells.Methods:1. PP2Ac mRNA expression of7groups of pancreatic cancer cells and11cases ofpancreatic cancer specimens which contained pancreatic cancer tissues and adjacent tissueswas tested by Real time-PCR.2. After the treatment of LPS, PP2Ac mRNA and protein expressions of pancreaticcancer cell line SW1990was detected by Real time-PCR and Western Blot.3. After the treatment of LPS, invasion of SW1990cells was determined byTranswell.4. The coding sequence of PP2Acα (PP2Ac α isoform) was cloned into pIRES2-EGFPvector, generating the PP2Acα overexpression plasmid, pIRES2-EGFP-PP2Acα. PP2Acwas overexpressed in pancreatic cancer cells by using transient transfection.5. Divided the SW1990cells into empty vector group and PP2Acα overexpression group, then divided the two groups into control group and LPS treated group within group,to investigate whether the effect of LPS on invasion was executed through a PP2Ac-dependent manner.Results:1. The expression of PP2Ac was significantly lower in pancreatic cancer tissues thanin adjacent tissues. The expression of PP2Ac in pancreatic cancer cells was also at a lowlevel.2. LPS inhibited both the mRNA and protein expressions of PP2Ac in pancreaticcancer cell line SW1990.3. LPS increased the invasive ability of SW1990cells.4. Plasmid pIRES2-EGFP-PP2Acα and PP2Acα overexpression SW1990cells wereconstruction.5. Overexpression of PP2Ac impaired the promotion of LPS on the invasion ofpancreatic cancer cells.Conclusion:LPS increased the invasive ability of pancreatic cancer cells through inhibition on theexpression of PP2Ac.