The Potential Role Of PADI2 In Promoting The Growth Of Endometrial Cancer

Objective:Endometrial carcinoma(EC)is the most common gynecologic cancer in developed nations,and the annual incidence is projected to increase.The peptidylarginine deiminases(PADs)are a family of calcium-dependent enzymes that post-translationally convert positively charged arginine redidues to neutrally charged citrulline.This activity is termed citrullination or deimination,and the modification results in the disruption of ionic and hydrogen bonds within the substrate proteins causing wide-ranging effects on target protein structure,function,and protein-protein interactions.PADI2 has been reported involved in various inflammatory diseases.Recently,its novel roles in cancers including squamous carcinomas,multiple myeloma and colorectal cancer,have attracted more attention.However,its role in endometrial carcinoma is unexplored.Therefore,our study is to investigate the potential role of PADI2 in endometrial carcinoma and the possibly molecular mechanism underlying the biological effects of PADI2.Methods:1.Determing PAD 12 expression in clinical endometrial carcinoma tissues.2.Identification of PADI2 expression in endometrial carcinoma cells by western blot.3.Establishing PADI2 knockdown stable cell lines using short hairpin interference(shRNA),and identifying the potential role of PADI2 in endometrial cancers.4.Performing RNA-seq analysis to identify genes regulated by PADI2 in endometrial cell line,and explore the signaling pathways involved in the regulation of endometrial cancer cell proliferation.5.Confirming the changes of relative signaling pathways and target genes expression upon PADI2 knockdown by western blost and RT-PCR analyses.Results:PADI2 is highly expressed in clinical endometrial cancer tissues.Stable PADI2 knockdown in endometrial cancer cells significantly decreased cell proliferation,colony formation and wound healing abilities in vitro and tumorigenesis in vivo compared to control cells.The RNA-seq analysis in PADI2 knockdown cells identified several key genes involved in regulation of tumorigenesis including IGF2BP1,SH3GL3,MMP16,Hl9.Along with the changes of gene expression,multiple signaling pathways were also identified in PADI2 knockdown cells,with phosphorylated extracellular signal-regulated kinase(ERK)being the most significant.Conclusion:PADI2 was significantly overexpressed in endometrial cancer cells,and positively associated with endometrial carcinomas.The carcinogenic characteristics of PADI2 in endometrial carcinoma are possibly exerted through ERK signaling pathway.