Inflammation drives
prostate cancer (PCa) progression. While
inflammation is a
cancer hallmark, the underlying mechanisms mediating
inflammation-induced PCa are still under investigation.
Interleukin-1 (IL-1) is an inflammatory
cytokine that promotes
cancer progression, including PCa
metastasis and
castration resistance. We previously found that acute
IL-1 exposure represses PCa
androgen receptor (AR) expression concomitant with the upregulation of pro-survival
proteins, causing de novo accumulation of
castration-resistant PCa cells. However, acute
inflammation is primarily anti-tumorigenic, while chronic
inflammation is pro-tumorigenic. Thus, using the LNCaP PCa cell line as model, we found that PCa cells can evolve insensitivity to chronic
IL-1 exposure, restoring AR and AR activity and acquiring
castration resistance. In this paper we expanded our chronic
IL-1 model to include the MDA-PCa-2b PCa cell line to investigate the response to acute versus chronic
IL-1 exposure and to compare the gene expression patterns that evolve in the LNCaP and MDA-PCa-2b cells chronically exposed to
IL-1.
METHODS: We chronically exposed MDA-PCa-2b cells to IL-1α or IL-1β for several months to establish sublines. Once established, we determined subline sensitivity to exogenous
IL-1 using cell viability assay, RT-qPCR and western blot.
RNA sequencing was performed for parental and subline cells and over representation analysis (ORA) for geneset enrichment of biological process/pathway was performed.
RESULTS: MDA-PCa-2b cells repress AR and AR activity in response to acute
IL-1 exposure and evolve insensitivity to chronic
IL-1 exposure. While cell biological and molecular response to acute
IL-1 signaling is primarily conserved in LNCaP and MDA-PCa-2b cells, including upregulation of NF-κB signaling and downregulation of cell proliferation, the LNCaP and MDA-PCa-2b cells evolve conserved and unique molecular responses to chronic
IL-1 signaling that may promote or support
tumor progression.
CONCLUSIONS: