Abstract 3261: Improving targeted therapy in female patients with lung squamous cell carcinoma

Abstract

Abstract Non-small cell lung cancer (NSCLC) will claim the lives of ~60,000 female patients in the US in 2023. Lung squamous cell carcinoma (LUSC) is a subtype of Non-Small Cell Lung Cancer (NSCLC) that comprises ~30% of NSCLC and is characterized by high metabolic activity. Specifically, LUSC typically exhibits elevated rates of both glucose and glutamine metabolism driven by the PI3K-AKT-mTOR and KEAP1/NRF2 pathways. Further, a paucity of identifiable genetic drivers in LUSC has resulted in a lack of effective targeted therapies for patients with this devastating disease. Despite recent advances in therapy, the 5-year survival rate for patients with advanced NSCLC is 6%, underscoring the need for better treatment options. Importantly, no significant sex bias is seen in the newly diagnosed cases of lung cancer (~50%M/~50%F) (American Cancer Society, 2023), yet there are no sex-specific therapeutic approaches in clinical use. We demonstrated that the catalytic mTOR kinase inhibitor TAK228 can be utilized to effectively treat LUSC tumors via inhibition of glycolysis, an approach that is currently being evaluated on two phase I/II clinical trials (NCT02417701, NCT04250545), launched as a direct result of our pre-clinical work. However, our pre-clinical data suggests that despite the potential benefit of TAK228 inhibition in LUSC, a subset of tumors are resistant to TAK228 despite on-target activity of mTOR inhibitor, leading to the rationale of the current hypothesis, namely the possibility that sex-specific differential effects of TAK228 may exist. To evaluate this hypothesis, we have generated preliminary data demonstrating that sex is a determinant of TAK228 response in LUSCs, whereby male mice are significantly more sensitive to mTOR inhibition than females. Follow-on experiments have demonstrated that the anti-estrogen therapy (Letrozole) sensitized previously resistant female mice bearing LUSCs to TAK228, suggesting an estrogen-related link to TAK228 resistance in females. Additionally, RNASeq and biochemical analyses identified pathways that are upregulated in TAK228 resistant female mice with LUSC tumors. These results suggest that the estrogen may play a key role in the observed pattern of female resistance to mTOR inhibition. As such, the goal of the current proposal is to evaluate the catalytic mTOR kinase inhibitor TAK228, in combination with anti-estrogen therapy as a therapeutic strategy to treat LUSC in females. Citation Format: Milica Momcilovic, David Shackelford. Improving targeted therapy in female patients with lung squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3261.