Dual effects of human adipose tissue-derived mesenchymal stem cells on the NF-κB pathway in tumor growth of A549 lung adenocarcinoma cells and HT-29 colon cancer cells

Abstract

Human adipose tissue-derived mesenchymal stem cells (hATMSCs) have a great potential as therapy for various diseases and in regenerative medicine. However, emerging evidence suggests that human stem cells have both promoting and inhibitory effects on tumor growth. For the clinical use of hATMSCs as a novel cell therapy, it is important to determine in which tumor environments hATMSCs have tumor supporting effects or suppressing effects and to understand the underlying mechanisms. In this study, hATMSCs affected tumor growth differently depending on the types of tumor cell. Among several types of tumor cell lines, the hATMSCs particularly inhibited the growth of A549 lung adenocarcinoma cells, but promoted the growth of HT-29 colon cancer cells in an in vivo xenograft model. Additional results from an in vitro study were coincided with the in vivo experiment of hATMSCs effects on tumor growth in A549 and HT-29 cell lines. The hATMSCs induced apoptosis and inhibited proliferation of A549 lung cancer cells, but the hATMSCs conversely affected the HT-29 colon cancer cells. Also, the change in NF-κB expression level after hATMSC treatment was the same in both the in vivo and in vitro experiments. The expression level of phosphorylated NF-κB p65 was reduced in A549 tumor cells, but the level was increased in HT-29 tumor cells. Altogether, we demonstrated dual effects of hATMSCs, which included an inhibiting effect on A549 and a promoting effect on HT-29. The expression level of NF-κB p65 was correlated with these dual effects in the A549 and HT-29 tumor cell lines.