IL-32α has differential effects on proliferation and apoptosis of human melanoma cell lines.

Background: Interleukin-32 (IL-32) is a recently recognized intracellular, proinflammatory cytokine which may play a role in cancer metastasis and patient survival. The role of IL-32 in cancer, especially its direct effect on cancer cells, is not well understood.

Material And Methods: Clonogenic assay, PCNA staining, Quick Cell Proliferation assay, TUNEL staining, and caspase-3 activity assay were used to investigate the in vitro role for IL-32α in human melanoma growth. We further investigated the possible molecular mechanisms using RT-PCR and immunohistochemical staining.

Results: Exogenous administration of IL-32α inhibited proliferation of the HTB-72 human melanoma cell line, but had little effect on other melanoma cell lines. Inhibition of proliferation in HTB-72 correlated with increased expression of p21 and p53. IL-32α administration also increased apoptosis in HTB-72. This finding correlated with increased expression of TRAILR1.

Conclusions: The data presented suggest a direct effect of IL-32α on the growth of human melanoma and give some insight into the mechanisms which may in part govern this effect. J. Surg. Oncol. 2016;113:364-369. © 2016 Wiley Periodicals, Inc.