Abstract 1475: Investigating the carcinogenic effects and the mechanism of cadmium exposure on WPMY-1 prostate myofibroblast cell line

Abstract Prostate cancer (PCa) is the second most common cancer among males with an incidence rate of PCa is 288,300 new cases annually. Risk factors include age, genetics, and lifestyle, but the underlying stimuli remain largely uncertain. One potential emerging cause of PCa is exposure to metal carcinogens as cadmium (Cd) which is now classified as a group I human carcinogen. Chronic exposure to Cd on epithelial cells has been extensively shown to induce carcinogenesis, making it a likely contributor to PCa development. In this study, we expand this information by examining how chronic Cd exposure affects prostate-derived myofibroblast (WPMY-1) cells transforming into a cancer-associated fibroblast like phenotype. To study the transformation, WPMY-1 cells were treated with 500nM of Cd for a period of 11 months establishing the WPMY-1 Cd model. Fibroblasts are a crucial tumor microenvironment (TME) component and potentially contribute to PCa progression when transformed and activated into cancer-associated fibroblasts (CAFs). To begin, we used an MTT assay to measure the effect of Cd toxicity on normal prostate myofibroblasts versus WPMY-1 Cd. The data showed that 10µM Cd solution was toxic to WPMY-1 cells, but WPMY-Cd cells depicted high cell viability at 50 µM dose, conferring to chronic Cd exposure improved resiliency to Cd toxicity. We analyzed the expression of CAF-specific markers in WPMY-Cd cells, such as vimentin, FAP, α-SMA, and PDGFR-β. WPMY-Cd cells showed a distinct upregulation for these markers when compared to untreated WPMY-1 cells, suggesting that chronic exposure to Cd promotes CAF-like phenotypic transformation in WPMY-Cd. To further ascertain the cancer-promoting properties of WPMY-Cd, an in vitro 3-D spheroid assay was performed by growing the cells on a Matrigel scaffold. The WPMY-Cd cells formed many more tumor-like spheroid structures than WPMY-1 and exhibited sprouting. The sprouting spheroids displayed lamellipodium and filopodium-like structures, demonstrating the initiation of migratory phenotype in WPMY-Cd. Additionally, previous research suggests that CAFs may play a role in PCa progression by promoting tumor growth via the secretion of cytokines and growth factors. We tested this theory by exposing Cd-treated epithelial (BPH-Cd) cells to conditioned media containing secretions from CAFs and WPMY-Cd. WPMY-1 Cd conditioned media in conferring cell migration on epithelial BPH-Cd cells was confirmed by a wound healing assay wherein BPH-Cd cells treated with WPMY-1 Cd conditioned media led to complete wound closure in 24 hours as compared to WPMY-1 and CAF conditioned media. Overall, there is considerable evidence that Cd exposure in fibroblasts may play a crucial role in PCa disease progression and is a promising area for researching PCa treatment strategies against a crucial component of the tumor microenvironment. Citation Format: Sakshi V. Bansod, Gnanasekar Munarithinam. Investigating the carcinogenic effects and the mechanism of cadmium exposure on WPMY-1 prostate myofibroblast cell line [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 1475.