IL-10/IL-10 receptor signaling regulates TIMP-1 expression in primary human prostate tumor lines.
An IL-10 responsive signal protein, termed IL-10E1, was cloned from human prostate cancer PC-3 ML cells based on its binding affinity for a novel enhancer element (i.e., HTE-1: 5'-CACGATGACTCATCACTGTTGAAAGACA-3') of the Tissue Inhibitor of metalloproteinase-1 (TIMP-1) gene. Electrophoretic mobility shift assays (EMSAs) and enzyme linked immuno-sandwich assays (ELISAs) showed that IL-10 stimulated the rapid translocation of IL-10E1 to the nucleus and the activation of TIMP-1 expression in 4 different androgen dependent primary prostate tumor lines generated in our laboratory (i.e. HPCA-5a, 5b, 5c and 5d lines). IL-10 signaling was blocked by a variety of agents, including IL-10 receptor antibodies, alpha-toxin, and Genistein. The inhibition of IL-10 signaling and IL-10E1 expression correlated directly with a significant decrease in TIMP-1 expression by the HPCA-5a, 5b, 5c and 5d cell lines. Following permanent transfection of HPCA-5a and 5c cells with the IL-10 gene the growth of tumor xenografts in SCID CB17 mice was severely retarded, yielding tiny, poorly vascularized tumors by approximately 90 days post-inoculation s.c. ELISAs showed that these tumors expressed elevated levels of IL-10, IL-10E1 and TIMP-1 compared with tumors from non-transfected or Mock transfected cell lines. We conclude that the IL-10/IL-10 receptor axis (and IL-10E1 signaling) regulation of TIMP-1 expression plays a key role in inhibiting tumor growth, perhaps by blocking tumor vascularization.
Wang
Min
M
Department of Pathology and Laboratory Medicine, MCP Hahnemann University, Broad & Vine, Philadelphia, PA 19102, USA.
Hu
Youji
Y
Shima
Ischiro
I
Stearns
Mark E
ME
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D002460:Cell Line; D017690:Cell Transplantation; D004742:Enhancer Elements, Genetic; D004789:Enzyme Activation; D015972:Gene Expression Regulation, Neoplastic; D019833:Genistein / Q000494:pharmacology; D006801:Humans; D016753:Interleukin-10 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008297:Male; D051379:Mice; D016513:Mice, SCID; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D018123:Receptors, Interleukin / Q000378:metabolism*; D053701:Receptors, Interleukin-10; D015398:Signal Transduction; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*; D014183:Transplantation, Heterologous; D010738:Type C Phospholipases / Q000494:pharmacology
D000970:Antineoplastic Agents; D018123:Receptors, Interleukin; D053701:Receptors, Interleukin-10; D019715:Tissue Inhibitor of Metalloproteinase-1; D016753:Interleukin-10; D019833:Genistein; D010738:Type C Phospholipases