Abstract 6539: Lung cancer microphysiological systems for modeling sex-specific effects of estradiol on treatment response and proangiogenic capacity

Abstract Lung cancer (LC) is the leading cause of cancer deaths in the US, accounting for 20.4% of all cancer deaths. LC incidence and progression exhibits distinct sex differences. Despite higher rates of smoking-related LC in men, premenopausal women never-smokers experience higher age-matched incidence and worse outcomes, suggesting a role for estrogens in disease initiation and progression. Along these lines, combining anti-estrogenic therapy with platinum-based agents such as cisplatin has been shown to enhance cytotoxicity, thereby underscoring the influence of sex hormones on LC treatment responses. Regarding LC progression, estradiol (E2) is known to potentiate angiogenesis in various contexts. A lack of sex-specific cellular models has limited in vitro investigations of sex hormone modulation of LC treatment responses and progression. This study aims to define E2’s sex-specific effects on LC growth characteristics and angiogenesis within cisplatin-treated LC tumor microenvironments. Methods: A549 spheroids were seeded in collagen I + 5% Matrigel and cultured in hormone-depleted medium as a baseline. Proliferation and cytotoxicity post E2 + cisplatin treatment was assessed via Ki67 and caspase 3/7 staining and quantification. A membrane-free organ chip that patterns a vascularized margin tissue and an engineered tumor microenvironment (TME) was used to model LC angiogenesis. Morphometric analysis of lectin-stained vasculature was used to quantify sprouting induced by VEGF gradients or TME-secreted growth factors. Patient-derived LC organoids (LC-PDO) were maintained and expanded in Matrigel. For angiogenesis assays LC-PDO were combined with sex-matched cancer-associated fibroblasts in a collagen I, fibrin, and Matrigel to engineer LC TMEs. Results: The baseline Ki67 index of 27 +/- 22% in A549 spheroids was decreased to 8 +/- 5% (p=0.042) by 25 μM cisplatin. The baseline caspase 3/7 index of 4 +/- 4% was increased to 49 +/- 9% (p<0.01) with cisplatin treatment. The addition of 0.1 nM E2 dampened the effect of 25 μM, as evidenced by a Ki67 index of 14 +/- 12% and a caspase 3/7 index of 16 +/- 5%. E2-rich medium significantly increased sprouting angiogenesis induced by externally applied VEGF gradients in female models. Studies using spheroids comprised of cisplatin-resistant A549 derivatives selected for in expansion culture simultaneously displayed features of EMT, pseudo-dormancy, and an increased proangiogenic capacity. Conclusions: Our proof-of-concept studies with A549 cells demonstrate that E2 decreases cisplatin toxicity. Ongoing work will reveal sex-specific effects of E2 on cisplatin toxicity and sprouting angiogenesis in LC-PDO models. This research could potentially inform the development of sex-specific LC treatment strategies that account for hormonal status and integrate modulators of sex hormone signaling in combination therapies. Citation Format: Wills Kpeli, Conner Sweat, Mark J. Mondrinos. Lung cancer microphysiological systems for modeling sex-specific effects of estradiol on treatment response and proangiogenic capacity [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 6539.