Interleukin-6 stimulates cell proliferation of rat pituitary clonal cell lines in vitro

• Published in: Journal of endocrinological investigation Vol. 18; no. 2; pp. 83 - 90
• Main Authors: SAWADA, T, KOIKE, K, KANDA, Y, IKEGAMI, H, JIKIHARA, H, MAEDA, T, OSAKO, Y, HIROTA, K, MIYAKE, A
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Milano Kurtis 01-02-1995
• Subjects: Animals; Binding Sites; Biological and medical sciences; Cell Count - drug effects; Cell Division - drug effects; Dose-Response Relationship, Drug; Female; General aspects (metabolism, cell proliferation, established cell line...); Granulocyte Colony-Stimulating Factor - pharmacology; Interferon-gamma - pharmacology; Interleukin-6 - pharmacology; Medical sciences; Pituitary Gland - cytology; Pituitary Gland - drug effects; Pituitary Gland - physiology; Rats; Rats, Wistar; Recombinant Proteins - pharmacology; Tumor cell; Tumor Cells, Cultured; Tumors; Cell proliferation; Cell culture; Rat; Cytokine; Rodentia; Cell biology; Adenohypophysis; Interleukin 6; Vertebrata; Mammalia; Animal; Mitogen; Tumor cell
• ISSN: 0391-4097; 1720-8386
• DOI: 10.1007/BF03349706

We investigated the effect of recombinant human IL-6 (rhIL-6) on cell proliferation using the MtT/E rat pituitary tumor cell line, which was recently established by Inoue et al. This cell line expresses the homeodomain protein Pit-1/GHF 1 and does not produce any significant amount of pituitary hormones, but retains its tumorigenicity by back-transplantation into rats, resulting in production of prolactin. MtT/E cells were seeded into Falcon 24-well plates at a density of 2 x 10(4) cells/well in a cultured medium, containing 10% horse serum and 2.5% fetal bovine, with test drug. After four-days (12 days for the time-course study) incubations, the cells were counted using a hemocytometer. Incubation for 4 days with rhIL-6 caused concentration-dependent stimulation of MtT/E cell growth and [3H]-thymidine incorporation into MtT/E cells. Addition of 20 ng/ml rhIL-6 to the culture medium stimulated MtT/E cell growth in a time-dependent manner, withdrawal of rhIL-6 from the culture medium reduced MtT/E cell growth, and re-addition of rhIL-6 to the culture medium again stimulated MtT/E cell growth. Among the cytokines tested, granulocyte colony-stimulating factor (rh G-CSF) also showed a slight but significant mitogenic activity on the MtT/E cells. Analysis of 125I-rhIL-6 binding to the MtT/E cells indicated a dissociation constant of 0.953 x 10(-9) mmol/l and the presence of 968 binding sites per cell.