Abstract 4725: Phenotypic single-cell analysis of nuclear stress responses in drug-treated prostate cancer cells

Abstract Chemotherapy with anti-cancer drugs aims to stop the growth of cancer cells either by killing them or by stopping them from dividing. The different specificities in inducing cellular damage responses are incompletely understood currently and may underlie the preferential effectiveness of anti-cancer drugs against different types of cancer cells. Better understanding and tools to measure drug-induced phenotypes in vitro may aid in assessing cellular heterogeneity of responses, determining potential effectiveness, estimating amount and types of adverse effects, and predicting likelihood of surviving populations for residual disease. To measure the types and extent of nuclear stress responses to cancer drugs, we studied nuclear organelle, namely nucleolar and Cajal body, phenotypes to drug-induced stress in prostate cancer cells. We utilized organelle-specific markers NPM, Fibrillarin, Coilin, and SMN1 in immunofluorescence staining to determine suitable markers for nuclear organelle stress. We used three different prostate cancer cells lines representing different biological types of advanced prostate cancer (AR positive, AR negative, and expressing AR transcript variant). Based on initial assessments, NPM and coilin immunostaining were selected for automated phenotypic analysis screening for drug effects. Using AI-assisted nuclear segmentation and feature-based single-cell phenotypic analysis, we demonstrated quantitative effects on nuclear morphology, nucleoli, and Cajal bodies with drug treatments. A proof-of-principle study with platinum-based chemotherapeutic agents in clinical use demonstrated heterologous responses to the platinum drugs that are associated with prostate cancer cell types with different AR status. Further, we have defined the corresponding quantitative responses for androgen deprivation therapy (ADT) drugs enzalutamide and bicalutamide in AR-positive prostate cancer cells. Our findings evidence variability of prostate cancer cells’ response to chemotherapy and have implications in future therapy regimen considerations. Furthermore, we have developed a fluorescence light microscopy-based method to assess nuclear stress response phenotypes in prostate cancer cells that can be used for high throughput drug screening. Citation Format: Enkhzaya Batnasan, Minttu Kärkkäinen, Sonja Koivukoski, Pekka Ruusuvuori, Leena Latonen. Phenotypic single-cell analysis of nuclear stress responses in drug-treated prostate cancer cells [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 4725.