SFRP1 and PTGS2 are potential biomarkers of tumorigenic properties in human placenta-derived mesenchymal stem cells

Abstract Background Mesenchymal stem cells (MSCs) display tumour tropism and have been explored as cellular vehicles to deliver anti-cancer agents. As cellular components of the tumour microenvironment, MSCs also influence tumour progression. However, the tumour transformation-related genes of MSCs are not well understood since either oncogenic or tumour suppressor effects within these cells have been reported. Here, we aimed to identify potential biomarkers capable of tumorigenic risk by RNA-seq analysis of human placenta tissue-derived MSCs (hPTMSCs) exposed to the carcinogenic agent 3-methylcholanthrene (3-MC). Results Twenty-nine tumour transformation-related genes and three pluripotency-related genes were identified as differentially expressed genes (DEGs) in hPTMSCs. Importantly, SFRP1 and PTGS2 were further identified as tumour suppressors and oncogenes in hPTMSCs, respectively. The overexpression of SFRP1 and PTGS2 was positively correlated with the expression of the pluripotent markers OCT4, CMYC and NANOG in the human lung adenocarcinoma cell line A549, and the low expression of SFRP1 and PTGS2 was inversely correlated with the expression of the pluripotent markers SOX2, OCT4 and NANOG in hPTMSCs. Interestingly, overexpression of SFRP1 led to reduced cell viability, colony formation and migration of A549 cells. In contrast, the ectopic expression of PTGS2 exerted the opposite effect. Conclusions These results indicate that hPTMSCs with high PTGS2 expression but low SFRP1 expression may have more potential tumorigenic capacity. Taken together, this study suggests that PTGS2 and SFRP1 may be valuable biomarkers for quality and safety control of hPTMSC preparations in clinical applications, which warrants further study.