Abstract 5321: Chronic use of tobacco products promotes breast cancer progression through α7 nAChR/STING pathway activation

Abstract Tobacco-use is associated with an increased risk of developing aggressive breast cancer, however the cause remains unclear. While there is a dose-dependent decrease of patients’ overall survival due to tobacco-use, the risk persists even after cessation. Here we show that chronic treatment with of breast cancer cells with low-dose nicotine significantly increases tumorsphere formation, self-renewal and tumor growth, while the acute treatment has little effect. Interestingly, these outcomes were noted even weeks after nicotine treatment was stopped. Mechanistically, this was attributed to α7 nAChR, previously described as an essential regulator of inflammation. In fact, α7 nAChR knock-out prevented activation of the STING antiviral pathway by reducing the nicotine-induced mRNA expression of STING, CCL5, CXCL10 and STAT3. Overall, these findings highlight long-term impact of nicotine on cancer progression through α7 nAChR/STING pathway. This may inform new biomarkers for diagnosis and potential new treatment strategies to combat tobacco-related breast cancers. Citation Format: Samson Mugisha, Shahnawaz Baba, Shreyas Labhsetwar, Richard Klemke, Jay Desgrosellier. Chronic use of tobacco products promotes breast cancer progression through α7 nAChR/STING pathway activation 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 (6Suppl): Abstract nr 5321.