Spontaneous release of interleukin-6 by primary cultures of lymphoid and tumor cell populations purified from human ovarian carcinoma.
Interleukin-6 (IL-6) is a cytokine that has been implicated as a growth factor in human ovarian carcinoma, yet the in vivo source of IL-6 in patients remains undefined. We measured IL-6 by ELISA in cell-free ascites (CFA) of 19 patients with ovarian carcinoma. IL-6 was detectable in all samples (mean level 3.3 ng/ml). To identify the cellular source of IL-6, we measured this cytokine by ELISA in 24-48 h supernatants of cultured lymphocyte-, macrophage-, and tumor cell-enriched populations purified from three solid ovarian carcinomas by centrifugal elutriation. All cell populations spontaneously released IL-6; however, tumor cells and tumor-associated macrophage released levels of IL-6 that greatly exceeded those released by tumor-associated lymphocytes. Kinetic studies revealed that IL-6 was detectable at 6 h and that levels increased in all cultures examined over a 48 h time course. These data suggest that both tumor and infiltrating host cells may be the source of the high levels of IL-6 found in carcinomatous ascites. Furthermore, although all three cell types examined may contribute to IL-6 production in patients with ovarian carcinoma, tumor cells are perhaps the most clinically significant source.
Burger
R A
RA
Department of Molecular Biology and Biochemistry, University of California, Irvine 92717, USA.
Grosen
E A
EA
Ioli
G R
GR
Van Eden
M E
ME
Park
M
M
Berman
M L
ML
Manetta
A
A
Disaia
P J
PJ
Granger
G A
GA
Gatanaga
T
T
D000230:Adenocarcinoma / Q000276:immunology / Q000473:pathology; D001202:Ascitic Fluid / Q000276:immunology; D002478:Cells, Cultured; D018283:Cystadenocarcinoma, Papillary / Q000276:immunology / Q000473:pathology; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D007700:Kinetics; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology*; D008264:Macrophages / Q000166:cytology / Q000276:immunology; D010051:Ovarian Neoplasms / Q000276:immunology* / Q000473:pathology; D014407:Tumor Cells, Cultured
D015850:Interleukin-6