Cytokine profiling identifies an interaction of IL-6 and IL-1α to drive PSMA-PSA prostate clones.

Background: Several PSMA-PSA prostate clones have been identified during prostate cancer progression; however, until now, their in situ inflammatory characteristics have remained unclear.

Aim: We therefore investigated the interplay between proinflammatory cytokines and (PSMA,PSA) sub-groups.

Materials And Methods: 27 benign prostate hyperplasia (BPH) and 18 prostate cancers (PC) were enrolled in this study. Immunohistochemical analysis was performed. Serum levels of PSA were assayed by Immulite autoanalyser.

Results: In BPH and PC patients with elevated serum PSA levels, IL-1α was the most proinflammatory cytokine expressed in (PSMA+,PSA-) subgroup. However, most samples of (PSMA+,PSA+) subgroup had positive immunoreaction to IL-6. In samples of PC with PSA serum levels of 4-20ng/mL or >20ng/mL, immunoreaction to TNF-α was seen only in (PSMA+,PSA+) subgroup. Interestingly, several combinations of proinflammatory cytokines (IL-6, IL-1α and TNF-α) showed that coexpression of tissue PSMA and PSA was concomitant with high immunoreactions to (IL-6+,TNF-α-), (IL-6+,IL-1α+) and (IL-1α+,TNFα-) in BPH and PC patients. (PSMA,PSA) subgroup lacking tissue PSA expression showed a high immunoexpression of the profile (IL-6+,TNF-α-). The combinations of (IL-6-, TNF-α-) and (IL-6-, IL-1α-) were absent in (PSMA+,PSA-) and (PSMA+,PSA+) BPH sub-groups.

Conclusion: Collectively, these findings underscore the importance of TNF-α and highlight the interaction between IL-6 and IL-1α to generate an inflammatory microenvironment in driving (PSMA,PSA) prostate clones.