Abstract 6789: Identification of DGKA as a regulatory factor for paclitaxel resistance in lung cancer based on CRISPR screen and transcriptome sequencing

Abstract Background: Lung cancer is the second most prevalent cancer with the highest mortality rate in the world. Paclitaxel (PTX) is one of the most effective clinical chemotherapeutic agents for the treatment of lung cancer, but a variety of mechanisms induce its chemoresistance including alterations in microtubule-associated proteins, up-regulation of drug efflux systems. Lipid metabolism was reported to impact chemosensitivity, but the underlying mechanisms are to be clarified. Therefore, this study aims to exploring the molecular mechanisms of PTX resistance regulated by lipid metabolism, and to discover novel PTX resistant targets and therapeutic agents. Methods: Lipid metabolism related sgRNA library was used for CRISPR screen. PTX-resistant lung cancer cells were constructed for transcriptome sequencing. The key regulators were identified via integrating negative enriched genes in CRISPR screen and the differential ones in transcriptome sequencing. The regulation of PTX sensitivity by the key regulators was confirmed in deficient lung cancer cells. Transcriptome sequencing was applied to find downstream pathways, and immunoblotting and RT-qPCR were used to confirm the molecular mechanisms. Mouse models were used to investigate the safety and effectiveness of its inhibitors combined with PTX for lung cancer treatments in vivo. Results: DGKA is highly expressed in PTX-resistant lung cancer cells, and its deficiency significantly induced PTX sensitivity in lung cancer cells. DGKA knockdown significantly inhibited lung cancer cell proliferation, invasion and migration. In addition, DGKA depletion promoted PYX-induced cell apoptosis and G2/M-phase arrest in lung cancer cells. Transcriptomics showed that the MAPK signaling pathway was significantly enriched after DGKA knockdown, and further experiments confirmed that DGKA inhibition increased lung cancer cell sensitivity to PTX via inhibiting ERK phosphorylation. DGKA inhibitor (R59022) could induce the PTX sensitivity of lung cancer cells safely and effectively in vivo. Conclusion: DGKA promotes PTX sensitivity of lung cancer cells and alleviates PTX resistance through the MAPK pathway, providing preclinical evidence for targeting DGKA as a novel strategy for lung cancer therapy against PTX resistance. Citation Format: Jiang Luo, Mini Zhang, Jiawen Tang, Qingwei Wang, Yu Yuan, Min Xia, Yufei Yan, Yushuang Tan, Conghua Xie, Yan Gong. Identification of DGKA as a regulatory factor for paclitaxel resistance in lung cancer based on CRISPR screen and transcriptome sequencing [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 6789.