M. Esquenet et al., LNCAP PROSTATIC ADENOCARCINOMA CELLS DERIVED FROM LOW AND HIGH PASSAGE NUMBERS DISPLAY DIVERGENT RESPONSES NOT ONLY TO ANDROGENS BUT ALSO TO RETINOIDS, Journal of steroid biochemistry and molecular biology, 62(5-6), 1997, pp. 391-399
In the present paper, two strains of LNCaP cells derived from the same
source (American Type Culture Collection), but studied either at a lo
w passage number (LP) or at a high passage number (HP), were compared
in their response to R1881 (a synthetic androgen), all-trans-retinoic
acid (atRA), and 1 alpha,25-dihydroxycholecalciferol (VD3). [H-3]Thymi
dine incorporation and epidermal growth factor receptor (EGF-R) bindin
g were measured as parameters related to the proliferative response of
the cells. The secretion of prostate-specific antigen (PSA) and the m
RNA expression of PSA, prostatic acid phosphatase (PAP), and diazepam-
binding inhibitor (DBI) were used as parameters reflecting differentia
ted function. Marked differences were noted in the response of LP and
HP cells to androgens. [H-3]Thymidine incorporation displayed a bell-s
haped dose-response curve in both strains. The amplitude of the respon
se, however, was much higher in HP cells and growth inhibition at high
levels of R1881 was only observed in LP cells. On the contrary, andro
gen induction of PSA secretion and PSA mRNA expression, as well as the
expression of PAP was much more pronounced in LP cells, whereas DBI e
xpression was not altered according to passage number. LP cells and HP
cells also displayed striking differences in their response to atRA.
An up to 6-fold stimulation of [H-3]thymidine incorporation was observ
ed in LP cells, whereas in HP cells the only significant effect was gr
owth inhibition. VD3, on the contrary, inhibited [H-3]thymidine incorp
oration to a comparable degree in LP and HP cells. Only marginal effec
ts of atRA and VD3 were observed on PSA secretion. In both LP and lip
cells EGF-R levels were increased by androgens and to a slight extent
also by atRA and VD3. It is concluded that LP and HP LNCaP cells displ
ay markedly divergent responses not only to androgens but also to atRA
. The proliferative rather than antiproliferative effects of atRA in s
ome strains of LNCaP should caution against the uncontrolled use of th
ese agents, or of drugs affecting their metabolism, in patients with p
rostate cancer. (C) 1997 Elsevier Science Ltd. All rights reserved.