Autophagy-dependent Bidirectional Regulation of EMT by NFκB in Non-Small Cell Lung Cancer Cells

Background: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer worldwide. Autophagy and epithelial-to-mesenchymal transition (EMT) are key processes in maintaining cellular homeostasis; their dysregulation can accelerate carcinogenesis. The nuclear factor-kappa B (NFκB) transcription factor regulates genes involved in proliferation, survival, and development. Although crosstalk between autophagy and EMT, and NFκB’s involvement in each process, have been reported, evidence for its regulation of both mechanisms together in NSCLC is limited. Methods: We investigated the role of NFκB (p65 subunit) in EMT regulation under autophagy-induced and non-induced conditions in NSCLC cell lines. Previously generated NFκB-overexpressed and -suppressed NSCLC samples from our earlier work were used. Cells were subjected to autophagy-induced or non-induced conditions, and quantitative real-time polymerase chain reaction (qRT-PCR) was performed to assess expression levels of EMT-related genes: positive regulators (Snail, Slug, N-cadherin) and the epithelial marker E-cadherin. Results: Under autophagy-induced conditions, NFκB overexpression significantly increased EMT-promoting genes and suppressed E-cadherin. In non-induced conditions, NFκB overexpression suppressed EMT-promoting genes and increased E-cadherin. NFκB suppression produced opposite effects, confirming its regulatory role. These results suggest a bidirectional influence of NFκB on EMT, dependent on autophagic status. Conclusions: NFκB, previously shown by us to positively regulate autophagy, acts as an autophagy-associated EMT regulator in NSCLC. It promotes EMT under autophagy-induced conditions, potentially contributing to progression and metastasis in advanced disease, while under non-induced conditions it may help maintain epithelial characteristics. Targeting the NFκB/autophagy/EMT axis could support the development of personalized NSCLC therapies.