Abstract 1474: Interleukin-8 and NF-κB mediated signaling axis: A potential driver for cadmium-induced prostate carcinogenesis

Abstract

Abstract Cadmium (Cd) is a toxic heavy metal, ubiquitous in nature, and an industrial pollutant. Cadmium exposure can cause irreversible damage to lungs, liver and kidney including cancers. Alarmingly, abnormally high levels of cadmium are found in human prostate tissues. Studies on rodents have shown cadmium exposure causes liver, lung, and prostate cancers. The mechanism of carcinogenesis caused by Cd is multifactorial and specific organ carcinogenesis remains unclear. We and others have reported that the CXC-chemokine IL-8 drives cancer progression in prostate cancer (PCa). We tested a hypothesis that chronic cadmium-exposure induces upregulation of proinflammatory cytokines, such as IL-1β, IL-6, and IL-8, which individually or combined promote carcinogenesis and progression. The study used two non-transformed prostate epithelial cell lines (RWPE-1 and NHPrE1) to test whether continuous exposure to Cadmium chloride (CdCl2) perturbs cytokine expression pattern and selective silencing of elevated cytokines delays carcinogenesis and invasive potential. The CdCl2 exposed cells and culture conditioned media were analyzed regularly for changes in inflammatory milieu and for hallmarks of carcinogenesis. These studies measured changes in cell proliferation, production of cytokines (IL-8, IL-1β, IL-6, IFN-γ, TGF-β, and others), activation of Nuclear Factor-kB (NF-κB), and pro-tumorigenic factors, e.g., vascular endothelial growth factors (VEGF-A and B), cellular motility, and invasive potential, etc. Cells exposed to CdCl2 showed increased cell proliferation and clonogenic potential and specifically, increased expression of IL-8, it’s receptors (CXCR1 and CXCR2), IL-1β, and other cytokines & related genes. While un-exposed RWPE-1 cells did not express IL-8, it was the first cytokine to increase when exposed to CdCl2, followed by activation of NF-κB (p65-rel), VEGF-A, & B, CXCR1 and other markers. Gene silencing of IL-8 suppressed motility, invasion, and survival activity. These data supported that immediate-early IL-8 expression probably upregulates NF-κB mediated inflammatory signaling axis which is critical for Cd-induced carcinogenesis and may expose targets for countermeasures to prevent metal-induced toxicity & carcinogenesis. Citation Format: Kunj Bihari Gupta, Rajendra K. Singh, Juliette R. Seremak, Vinata B. Lokeshwar, Bal L. Lokeshwar. Interleukin-8 and NF-κB mediated signaling axis: A potential driver for cadmium-induced prostate carcinogenesis [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 1474.