IL-6 As a Potential Cell Released Marker of Prostate Cancer Cell Death

Abstract Introduction: Interleukin 6 (IL-6) is proinflammatory cytokine which is produced by cell when Nod-like receptors (NLRs) are activated. Increased production of IL-6 was shown to promote tumor growth and metastasis.Therefore, it could be suggested that activation of NLRs could support malignancy. PC-3, prostate tumor derived cells, was shown to produce IL-6; however, little is known about the role of NLRs in regulation of cytokine secretion. Method: PC-3 cells were seeded in 48 well plate cell culture plates and culturd in presence of VX765, Nigericin or Camptothesin. After 24 hours incubation, cell death was determined using Annexin V test. Additionally, IL-6 level was assessed in culture medium using Bio-Plex Pro™ Human Chemokine Panel (Biorad). Data was analyzed using One Way Anova, Post Hoc Tukey test, SPSS 20. Results: Viability of PC3 cells was reduced when treated with Nigericin (37.74±0.33%) and Champtothesin (10.10±0.23%) as compared to untreated cells (P<0.01), while VX765 did not affect cell viability (4.78±0.28 %; P= 0.645). Nigerecin significatly increased IL-6 production in PC3 cells when compared to untreated cells. Interestingly, IL-6 levels in culture medium of PC3 cells treated with nigerecin was significantly higher than that in cells treated with VX765 and campthothesin (p< 0.001). Conclusion: It appears that IL-6 can be produced by PC3 cells upon stmulation of NLRs. Since NLRs activation was associated with reduced cell vitality, we suggest that increased IL-6 level in culture medium could be the result of the cytokine release from dead cells. This study was supported by RFBR Grant #18-34-01000 and Program of Competitive Growth of KFU. Disclosures No relevant conflicts of interest to declare.