VIP and PACAP are autocrine factors that protect the androgen-independent prostate cancer cell line PC-3 from apoptosis induced by serum withdrawal.
1. In the present study, we describe the expression of the neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) as well as their receptors in PC-3 cells, a human prostate cancer cell line. In addition, we have investigated their role in apoptosis induced by serum starvation. 2. By RT-PCR and immunocytochemistry assays, we have demonstrated the production of VIP and PACAP in PC-3 cells. 3. We have demonstrated by RT-PCR and binding assays the expression of common PACAP/VIP (VPAC(1) and VPAC(2)) receptors, but not PACAP-specific (PAC(1)) receptors. The pharmacological profile of [(125)I]-VIP binding assays was as follows: VPAC(1) antagonist=VPAC(1) agonist>VIP>VPAC(2) agonist (IC(50)=1.2, 1.5, 2.3 and 30 nM, respectively). In addition, both receptor subtypes are functional since VIP, PACAP-27 or VPAC(1) and VPAC(2) agonists all increased the intracellular levels of cAMP. 4. The expression of both peptides and their receptors is similar in serum-cultured and serum-deprived PC-3 cells. The treatment of serum-deprived PC-3 cells with exogenous VIP or PACAP-27 increases cell number and viability in a dose-dependent manner, as demonstrated by cellular counting and MTT assays. The increased cell survival is exerted through the VPAC(1) receptor, since a VPAC(1), but not VPAC(2), receptor agonist, mimics the effects and a VPAC(1) receptor antagonist blocks it. Moreover, VIP and PACAP-27 inhibit genomic DNA fragmentation in PC-3 cells triggered by serum starvation, and increase the immunoreactivity of the antiapoptotic protein bcl-2. 5. Our results suggest that VIP and PACAP are autocrine/paracrine factors that protect PC-3 cells from apoptosis through VPAC1 receptors.
Gutiérrez-Cañas
Irene
I
Department of Biochemistry and Molecular Biology, University of Alcalá, E-28871 Alcalá de Henares, Spain.
Rodríguez-Henche
Nieves
N
Bolaños
Oscar
O
Carmena
María J
MJ
Prieto
Juan C
JC
Juarranz
María G
MG
D000728:Androgens / Q000235:genetics / Q000502:physiology*; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D019898:Autocrine Communication / Q000187:drug effects / Q000502:physiology*; D045744:Cell Line, Tumor / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D009479:Neuropeptides / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism*; D014660:Vasoactive Intestinal Peptide / Q000037:antagonists & inhibitors / Q000494:pharmacology*
C495401:ADCYAP1 protein, human; D000728:Androgens; D016895:Culture Media, Serum-Free; D009479:Neuropeptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D014660:Vasoactive Intestinal Peptide