Differential production of interleukin 6 in human osteosarcoma cells and the possible effects on neoplastic bone metabolism.
Interleukin 6 (IL-6) exerts well-established effects on cells of the immune system as well as on various other cell types. We have investigated the effects of IL-6 produced by human osteosarcoma cells on tumor cells from two clonal human osteosarcoma cell lines, KSU.C3 and NOS-1.C8. We were unable to identify any effects of IL-6 such as cell proliferation, alkaline phosphatase activity, osteocalcin production, or collagen synthesis on the bone-forming phenotypes. However, the KSU.C3 cell line, which showed a little osteoid and no bone formation and was accompanied by a few osteoclasts in the xenografted tumors, produced high levels of IL-6, the production of which was quickly and easily stimulated by various agents. On the other hand, the NOS-1.C8 cell line, which formed abundant osteoid or bone and was accompanied by no osteoclasts in the xenografted tumors, produced no detectable levels of IL-6 without stimulation, and the production of IL-6 in response to IL-1 beta was slower. Our data suggest that IL-6 produced by osteosarcoma cells does not play an important role in bone formation, but may mediate osteoclastic bone resorption.
Motoyama
T
T
Department of Pathology, Niigata University School of Medicine, Japan.
Hotta
T
T
Watanabe
H
H
Kumanishi
T
T
Ichikawa
T
T
Sekiguchi
M
M
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001842:Bone and Bones / Q000378:metabolism* / Q000473:pathology; D002455:Cell Division; D003094:Collagen / Q000096:biosynthesis; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008819:Mice, Nude; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D015675:Osteocalcin / Q000096:biosynthesis; D012516:Osteosarcoma / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D015850:Interleukin-6; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D015675:Osteocalcin; D003094:Collagen; D000469:Alkaline Phosphatase