Differential alterations of positive and negative regulators of beta catenin enhance endogenous expression and activity of beta catenin in A549 non small cell lung cancer (NSCLC) cells

Beta catenin has been well documented in previous studies to be involved in non small cell lung cancer (NSCLC). Beta catenin abundance and transcriptional activity are significantly regulated by several factors. Though it is well known that Akt and Gsk3 beta are respective positive and negative regulators of beta catenin, however, no single study has so far documented how the expression and activity of both positive as well as negative regulators play favorable role on beta catenin expression and activity in NSCLC. In this study, we compared expression and activity of beta catenin and its regulators in normal lung cell WI38 and NSCLC cell A549 by western blot, qRT-PCR and luciferase assay. We observed that beta catenin positive regulators (Akt and Hsp90) and negative regulators (Gsk3 beta and microRNA-214) have differential expression and/or activity in NSCLC cell A549. However the differentially altered statuses of both the positive and negative regulators rendered cumulative positive effect on beta catenin expression and activity in A549. Our study thus suggests that chemotherapeutic modulations of regulating factors are crucial when abrogation and/or inhibition of key oncogenic proteins are necessary for cancer chemotherapy.