Interleukin-6 trans-signalling differentially regulates proliferation, migration, adhesion and maspin expression in human prostate cancer cells.
Interleukin-6 (IL-6) is suggested to have a pathogenic role in the progression of prostate cancer (PC), therefore representing an attractive target for new therapies. However, due to the pleiotropy of this cytokine, targeting IL-6 results in different and unpredictable responses. In order to better understand the mechanisms underlying the different responses to the cytokine, we focused our attention on IL-6 receptors (IL-6Rs) that represent the first element in the cascade of cytokine-activated signalling pathways. IL-6 signal transduction may indeed occur through the membrane IL-6R (classical signalling) and/or through the less studied soluble IL-6R (sIL-6R; IL-6 trans-signalling (IL-6TS)). We provide the first evidence how responses to IL-6 may depend on the different content of IL-6Rs in PC. In particular, the studies of (3)H-thymidine incorporation and exploitation of different approaches (i.e. activation or inhibition of IL-6TS in sIL-6R-negative and -positive cell lines and transfection of IL-6R siRNA) allowed us to demonstrate that IL-6TS specifically accounts for an anti-proliferative effect of the cytokine in three PC cell lines that are known to respond differently to IL-6. Additionally, by applying migration-, scratch- and adhesion assays, we show that IL-6TS increases motility and migration and decreases adhesion of prostate cells facilitating thereby processes that determine metastasis initiation and spread. Finally, by western analyses, we uncovered an IL-6- and sIL-6R-dependent downregulation of the tumour suppressor maspin. Collectively, these data suggest that selective targeting of IL-6TS might allow to refine the currently available experimental anti-IL-6 therapies against PC.
Santer
Frédéric R
FR
Department of Urology, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria.
Malinowska
Kamilla
K
Culig
Zoran
Z
Cavarretta
Ilaria T
IT
D002277:Carcinoma / Q000235:genetics* / Q000473:pathology; D002448:Cell Adhesion / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects* / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D015850:Interleukin-6 / Q000494:pharmacology*; D008297:Male; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology; D019947:Receptors, Interleukin-6 / Q000819:agonists / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D015843:Serpins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D012995:Solubility; D015533:Transcriptional Activation / Q000187:drug effects
D015850:Interleukin-6; D019947:Receptors, Interleukin-6; C085344:SERPIN-B5; D015843:Serpins