Abstract 888: Elucidating the mechanisms of eATP-induced changes in cell growth, energy metabolism, and cancer stem cells in human non-small lung cancer A549 cells

Abstract

Abstract The tumor microenvironment (TME) has concentrations of extracellular ATP (eATP) 103-104 times higher than normal healthy tissues, implying that eATP may have important roles in tumor development and progression. Our previous study, cited by a Nature Reviews Cancer paper, showed that the extracellular ATP (eATP) is internalized by tumors via macropinocytosis, a type of endocytosis, to increase intracellular ATP (iATP) levels and support tumor cells growth, drug resistance, and cancer cell movement by initiating epithelial to mesenchymal transition (EMT). Recently, our lab found that eATP functions in promoting cancer cell growth, metastasis are similar to those of TGF-β, a well-known EMT and cancer stem cells (CSCs) inducer. Increasing reports state that the EMT and CSCs share some molecular links, but the detailed mechanisms and inductor of them are still far from clear. In this report, eATP’s function in CSCs induction was investigated first. Result shows that eATP treatment significantly induces the protein expression level of CSC related makers, increases cell colony numbers, and cell populations with CSC markers expressed in human lung cancer A549 cells. In addition, RNA-sequencing analysis reveals the gene Stanniocalcin 1 (STC1) is significantly upregulated in both eATP and TGF-β treatments. STC1 gene has been reported to be a competitive biomarker in the tracking of cancers’ progressing. Besides, STC1 exhibits concentration-dependent stimulation effects on electron transportation chain (ETC) and respiration. However, the detail function of STC1 gene in eATP induced cell growth is unknown. To find out the mechanism, CRISPR-Cas9 technique was used to generate STC1 gene targeted knockout (STC1 KO) A549 cells. STC1 KO cells show slower cell growth rate, lower intracellular ATP level and lower oxygen consumption rate (OCR) when compared with normal A549 cells in vitro. These results strongly indicate STC1 gene involved in eATP induced cell growth by alteration iATP level and metabolic profile. Overall, this study not only unravels new role of eATP in CSC induction, but also provides new mechanism of eATP induced cell growth by altering the protein expression level of STC1. Citation Format: Jingwen Song, Xiaozhuo Chen. Elucidating the mechanisms of eATP-induced changes in cell growth, energy metabolism, and cancer stem cells in human non-small lung cancer A549 cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 888.