TNF-MEDIATED CYTOTOXICITY AND RESISTANCE IN HUMAN PROSTATE-CANCER CELL-LINES

BACKGROUND. The contribution of TNF receptor (TNF-R) expression was in vestigated with respect to TNF sensitivity or insensitivity for androg en-dependent and androgen-independent human prostate cancer (PCA) cell lines, respectively. METHODS. Flow cytometric analyses using monoclon al antibodies against the 55-kDa receptor (TNF-R1) and the 75-kDa rece ptor (TNF-R2) indicated that both receptors were expressed on all thre e cell lines. RESULTS. Moreover, expression of TNF-R1 was greater than expression of TNF-R2 in these PCA cells. All three PCA cell lines pro duced IL-6. However, IL-6 production was enhanced when TNF-insensitive JCA-1 and PC-3 cells, but not TNF-sensitive LNCaP cells, were treated with rTNF (10(-9) M). CONCLUSIONS. These data suggest that the lack o f an antiproliferative effect of rTNF on the androgen-independent PCA cell lines PC-3 and JCA-1 is not due to the failure of these cells to express TNF-R, but may be related to the differences in TNF-mediated I L-6 expression by these PCA cell lines. (C) 1996 Wiley-Liss, Inc.