TY - JOUR
T1 - Apoptosis-related gene expression affected by a GnRH analogue without induction of programmed cell death in LNCaP cells
AU - Angelucci, Cristiana
AU - Iacopino, Fortunata
AU - Lama, Gina
AU - Capucci, Susanna
AU - Zelano, Giovanni
AU - Boca, Manila
AU - Pistilli, Alessandra
AU - Sica, Gigliola
PY - 2004
Y1 - 2004
N2 - Background: In this study we confirmed the ability
of a Gonadotropin Releasing Hormone (GnRH) agonist,
leuprorelin acetate (LA), to counteract or even suppress the 5·-
dihydrotestosterone (DHT)-stimulated growth of androgensensitive
prostate cancer cells (LNCaP). Since the cellular
mechanisms mediating this effect are not well defined, we
investigated the activity of LA, also in combination with DHT
or with cyproterone acetate (CA), on the expression of genes
(bcl-2, bax, c-myc) which may contribute to the proliferative
behaviour of LNCaP cells. In addition, experiments aimed to
evaluate the action of the analogue on apoptosis were
performed. Materials and Methods: Gene expression was
evaluated by RT-PCR and Western blotting on cells treated with
LA (10-11 or 10-6 M), alone or combined with 10-9 M DHT or
10-7 M CA. The occurrence of apoptosis following treatment
with LA (10-11, 10-6 or 10-5 M), alone or combined with 10-9 M
DHT, was assessed by DNA fragmentation analysis. Results:
Both the mRNA and protein of the anti-apoptotic gene bcl-2
were induced (30-125%) by DHT after 24-144 h. LA decreased
bcl-2 mRNA (10-40%), while it did not unequivocally affect
protein expression. The analogue always reduced (13-74%) both
mRNA and protein levels obtained under DHT treatment. The
mRNA and protein of the pro-apoptotic gene bax were downregulated
by DHT (15-40%), while LA generally induced bax
protein but not its mRNA. LA counteracted DHT activity, even
increasing bax protein levels over the controls. c-myc mRNA and
protein were enhanced by DHT (15-45%) but down-regulated
by LA (10-40%). Once more, the androgen effect was
antagonized by LA, sometimes reducing c-myc content below
the controls. CA produced the most similar effects to those
triggered by DHT. The hormonal treatment did not induce any
DNA fragmentation. Conclusion: In spite of gene modulation,
apoptosis was not observed under LA treatment, in agreement
with the lack of a cell growth effect when the analogue was used
alone. Nevertheless, the observed changes in gene expression
may be directly or indirectly involved in the antiproliferative
effect of LA on androgen-stimulated cells.
AB - Background: In this study we confirmed the ability
of a Gonadotropin Releasing Hormone (GnRH) agonist,
leuprorelin acetate (LA), to counteract or even suppress the 5·-
dihydrotestosterone (DHT)-stimulated growth of androgensensitive
prostate cancer cells (LNCaP). Since the cellular
mechanisms mediating this effect are not well defined, we
investigated the activity of LA, also in combination with DHT
or with cyproterone acetate (CA), on the expression of genes
(bcl-2, bax, c-myc) which may contribute to the proliferative
behaviour of LNCaP cells. In addition, experiments aimed to
evaluate the action of the analogue on apoptosis were
performed. Materials and Methods: Gene expression was
evaluated by RT-PCR and Western blotting on cells treated with
LA (10-11 or 10-6 M), alone or combined with 10-9 M DHT or
10-7 M CA. The occurrence of apoptosis following treatment
with LA (10-11, 10-6 or 10-5 M), alone or combined with 10-9 M
DHT, was assessed by DNA fragmentation analysis. Results:
Both the mRNA and protein of the anti-apoptotic gene bcl-2
were induced (30-125%) by DHT after 24-144 h. LA decreased
bcl-2 mRNA (10-40%), while it did not unequivocally affect
protein expression. The analogue always reduced (13-74%) both
mRNA and protein levels obtained under DHT treatment. The
mRNA and protein of the pro-apoptotic gene bax were downregulated
by DHT (15-40%), while LA generally induced bax
protein but not its mRNA. LA counteracted DHT activity, even
increasing bax protein levels over the controls. c-myc mRNA and
protein were enhanced by DHT (15-45%) but down-regulated
by LA (10-40%). Once more, the androgen effect was
antagonized by LA, sometimes reducing c-myc content below
the controls. CA produced the most similar effects to those
triggered by DHT. The hormonal treatment did not induce any
DNA fragmentation. Conclusion: In spite of gene modulation,
apoptosis was not observed under LA treatment, in agreement
with the lack of a cell growth effect when the analogue was used
alone. Nevertheless, the observed changes in gene expression
may be directly or indirectly involved in the antiproliferative
effect of LA on androgen-stimulated cells.
KW - Leuprorelin acetate, dihydrotestosterone, cyproterone acetate, apoptosis-related genes, prostate cancer
KW - Leuprorelin acetate, dihydrotestosterone, cyproterone acetate, apoptosis-related genes, prostate cancer
UR - http://hdl.handle.net/10807/160816
M3 - Article
SN - 0250-7005
VL - 24
SP - 2729
EP - 2738
JO - Anticancer Research
JF - Anticancer Research
ER -