TIMP-1 Modulation Correlates with KRAS Dependency and EMT Induction in NSCLC.

Abstract

Kirsten rat sarcoma viral oncogene homolog (KRAS) is one of the most frequently mutated genes in human cancer, including non-small cell lung carcinoma (NSCLC). Sustained expression of KRAS is required for survival in KRAS-dependent tumors. KRAS tumors can become independent upon bypassing this addiction. Tissue inhibitor of metalloproteinase-1 (TIMP-1) exhibits a range of novel functions in addition to its initially recognized activity as a physiological inhibitor of matrix metalloproteinases (MMPs). It has repeatedly been associated with cancer progression and poor prognosis in multiple cancers. This study investigates the relationship between TIMP-1 modulation and KRAS dependency in NSCLC. We found an inverse expression of KRAS and TIMP-1 in NSCLC lines. Modulating TIMP-1 levels altered KRAS expression and affected KRAS-dependency features. Overexpression of TIMP-1 decreases the KRAS levels in dependent cells and knocking-down TIMP-1 increases KRAS levels in independent cells with concomitant change in RAS-GTP levels. TIMP-1 modulation influenced apoptosis upon KRAS ablation, with TIMP-1 overexpression decreasing apoptosis in dependent cells and TIMP-1 knockdown increasing it in independent cells. Bioinformatic analysis depicted variant-specific perturbations between KRAS and TIMP-1 expression. Furthermore, EMT marker expression was altered upon TIMP-1 modulation, suggesting the role of TIMP-1 in EMT induction in KRAS-independent cells. These findings emphasize the intricate relationship between TIMP-1 and KRAS in NSCLC, shedding light on potential mechanisms underlying tumor behavior and response to therapy.