Abstract 936: Developing a sex-biased model for LKB1-mutant lung adenocarcinoma

Abstract

Abstract Liver kinase B1 (LKB1) is the third most frequently mutated gene in lung adenocarcinoma (LUAD), and LKB1-mutant lung cancers are resistant to existing targeted therapy or immune checkpoint blockade therapy. In the TCGA-LUAD dataset, LKB1 was found to be more frequently mutated in males than in females even after correcting for potential confounders (male versus female: 22.8% versus 11.3%, p < 6.9x 10-4, FDR = 0.033). Similar trends can be found in all other large LUAD datasets. However, the mechanistic basis of this bias is unknown because the existing mouse models of lung cancers either did not exhibit sex bias or showed female mice being more susceptible to the development of lung cancers. Here, we demonstrate that our lentivirus-inducing Kras/LKB1-mutant genetically engineered mouse model (GEMM) and tail-vein injection syngeneic model exhibit sex bias against the tumor formation in the female host. In our KRASLSL-G12D/LKB1fl/fl/Rosa-Luc GEMM mice, the lung tumor formation was monitored by bioluminescence imaging (BLI) and validated by immunohistochemistry of tumor bearing-lung. The sex bias of time to lung adenocarcinoma formation in males and females was determined by the Kaplan-Meier method. 97% (31/32) male GEMM developed LUAD after the induction, whereas only 58% (15/26) female GEMM developed LUAD (p=0.0001, log-rank). The tail-vein injection method used the WRJ388-AD1 cell line, which was derived from WRJ388. Tumor growth in the chest area was monitored by BLI and evaluated by the mixed-effects model. Sex bias preference for developing lung tumors in the male host reached significance on day 14 post-injection (p=0.0037) and lasted during the study (day 21, p=0.0021). On day 21, with the cutoff as 1x106 p/sec/cm2/sr in lung region, 100% male GEMM formed lung tumor while only 36% female GEMM formed lung tumor after the injection. Collectively, this KRAS/LKB1-mutant lung adenocarcinoma exhibits sex-biased tumor formation and growth, which are consistent with clinical data among LUAD patients. This model will provide researchers with opportunities to understand the mechanistic basis of this sex bias and to develop novel personalized therapies. Citation Format: Yijian Fan, Rui Jin, Xiuju Liu, Yuan Liu, Chunzi Huang, Mellissa Gilbert-Ross, Adam Marcus, Wei Zhou. Developing a sex-biased model for LKB1-mutant lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 936.