Abstract 5327: CDK2 inhibition produces persistent polyploid cancer cells with a survival advantage

Abstract Aneuploidy, a hallmark of cancer, drives chromosomal instability and antineoplastic drug resistance. Common in hematologic and solid tumors, centrosome amplification leads to supernumerary centrosomes, causing chromosomal missegregation in dividing cancer cells. This imbalance produces progeny with abnormal chromosome counts, leading to cell death, resistance to antineoplastics, and clinically-aggressive tumors. This study examined the effects of CDK2 inhibition on aneuploid lung cancer cells and tumors. It revealed that CDK2 antagonism triggers anaphase catastrophe through centrosome clustering disruption and multipolar mitosis. Unexpectedly, this also leads to the formation of a persistent population of polyploid, apoptosis-resistant cells. Using independent CDK2 inhibitors and shRNAs, we observed that some cancer cells underwent multipolar division and subsequent cell death. Others exhibited cytokinesis failure, resulting in multinucleated, and polyploid cancer cells that continued to survive and proliferate despite continuous CDK2 inhibition. Through time-lapse imaging with transfected FUCCI cell cycle probes and RNA-seq analysis of polyploid versus diploid populations, we identified upregulated CDK1-related pathways and kinesin (KIF) family members in the polyploid cellular population. This likely contributes to the persistent polyploid population, despite CDK2 antagonism. These findings were independently validated in vivo using intravital microscopy and patient-derived xenograft (PDX) lung cancer models. Intriguingly, polyploid and multinucleated cancer cells were found to proliferate post-CDK2 inhibitor treatments. In marked contrast, a polyploid population was not found in CDK2 inhibited primary human alveolar epithelial cells, indicating that this is a pathway that is preferentially activated in aneuploid cancer cells. Analysis of gene expression in TCGA lung cancer datasets linked CDK1 and KIF family overexpression to an unfavorable patient survival, implicating this persistent polyploid population as contributing to poor survival outcomes in lung cancer. These findings are relevant to the clinical development of CDK2 inhibitors. They indicate that despite the pro-apoptotic effects of CDK2 antagonism in aneuploid lung cancer cells, a population of drug-resistant, polyploid cells persists. We propose that a combinatorial therapy targeting CDK2 alongside polo-like kinase 4 (PLK4), CDK1 or kinesin family members would further disrupt centrosome clustering, eliminate polyploid cancer cells, and enhance tumor cell apoptosis and antineoplastic effects. This dual approach would enhance the anti-tumor efficacy of CDK2 inhibition, potentially overcoming resistance mechanisms. This provides a promising strategy to eradicate persistent lung cancer cells following CDK2 inhibition. Citation Format: Liliya Tyutyunyk-Massey, Zibo Chen, Xiuxia Liu, Masanori Kawakami, Adam Harned, Yeap Ng, Brian Luke, Sameul C. Okpechi, Blessing Ogunlade, Yair Alfaro, Roberto Weigert, Kedar Narayan, Xi Liu, Ethan Dmitrovsky. CDK2 inhibition produces persistent polyploid cancer cells with a survival advantage [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5327.