NFATc2 enhances tumor-initiating phenotypes through the NFATc2/SOX2/ALDH axis in lung adenocarcinoma

Abstract

Cancers display intratumoral genetic and molecular heterogeneity with tumor initiating cells (TIC) showing enhanced tumor phenotypes. In this study, we show the calcium pathway transcription factor NFATc2 is a novel regulator of lung TIC through the NFATc2/SOX2/ALDH1A1 regulatory axis. In vitro and in vivo cancer cell modeling demonstrated supportive evidences including cell renewal, tumorigenicity at limiting dose, cell motility, resistance to cytotoxic chemotherapy and EGFR targeted therapy. In human lung cancers, high NFATc2 expression predicts poor tumor differentiation, adverse recurrence-free and overall patient survivals. Mechanistic investigations identified NFATc2 response elements in the SOX2 3 enhancer region, and NFATc2/SOX2 coupling upregulates ALDH1A1 by binding to its 5 enhancer. Through this axis, oxidative stresses and reactive oxygen species induced by cancer drug treatment are attenuated, accounting for a mutation-independent mechanism of drug resistance. Targeting this axis provides a novel approach for the long term treatment of lung cancer through TIC elimination.