CKAP2L promotes non-small cell lung cancer progression through regulation of transcription elongation

Abstract

Chromosomal instability (CIN) is a driver of clonal diversification and intra-tumor heterogeneity, providing genetic diversity that contributes to tumor progression. It is estimated that ∼80% of solid cancers, including non-small cell lung cancer (NSCLC), exhibit features of CIN, which affects tumor growth and response to therapy. However, the molecular mechanisms connecting CIN to tumor progression are still poorly understood. Through an RNAi screen performed on genes involved in CIN and overexpressed in human lung adenocarcinoma samples, we identified the cytoskeleton-associated protein 2-like (CKAP2L) as a potential oncogene that promotes lung cancer proliferation and growth in vitro and in vivo. Mechanistically, CKAP2L directly interacted with RNA Pol II and regulated transcription elongation of key genes involved in spindle assembly checkpoint, chromosome segregation, cell cycle, and E2F signaling. Furthermore, depletion of CKAP2L increased the sensitivity of NSCLC cells to alvocidib, a pan CDK inhibitor, leading to a significant reduction of cell proliferation and an increase in cell death. Altogether, these findings shed light on the molecular mechanisms through which CKAP2L, a protein involved in CIN, promotes cancer progression and suggest that its inhibition represents a novel therapeutic strategy in NSCLC.