Journal of cellular signaling最新文献

Previously characterized as a purely immune mediated disease, sepsis is now recognized as a dysregulated multisystem response against a pathogen. Recognition of the infectious agent by pathogen recognition receptors (PRRs) can initiate activation of the NF-κB signaling pathway and promote the secretion of proinflammatory cytokines. During sepsis, the activation of NF-κB is dysregulated and results in cytokine storm, or the pathologic release of cytokines. Current treatments for sepsis rely on broad spectrum antimicrobial medications and fluid replacement therapy, to neutralize the inciting pathogen and maintain adequate blood pressure. The addition of vasopressor therapy is also utilized when sepsis progresses to septic shock, which is defined by treatment resistant hypotension. Even though modern treatment guidelines have improved clinical outcomes, the mortality rate of sepsis and septic shock is still 15-20% and 20-50%, respectively. To reduce mortality, recent sepsis treatment research has focused on investigating novel therapeutics that can attenuate the dysregulated NF-κB signaling pathway. Antioxidants, such as Retinoic acid and Oxytocin, can reduce activation of the NF-κB pathway by neutralizing stimulatory reactive oxygen species (ROS). Likewise, anti-inflammatory agents can also affect the NF-κB pathway by decreasing the secretion of proinflammatory cytokines, such as TNFα and IL-6. Novel anti-inflammatory cytokines, such as IL-37 and IL-38, have recently been characterized and shown to reduce inflammation in mice with bacterial sepsis. Separately, antioxidants and anti-inflammatory cytokines show promise as potential therapies for sepsis, however, a combined therapy including both agents may prove more beneficial in further improving clinical outcomes.

Introduction: 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: Our chronic IL-1 subline models can be used to identify underlying molecular mechanisms that mediate IL-1-induced PCa progression.