Induction of cell cycle arrest and apoptosis in human prostate carcinoma cells by a recombinant adenovirus expressing p27Kip1

• Published in: The Prostate 2002-09, Vol.53 (1), p.77-87
• Main Authors: Katner, Adrienne L., Hoang, Quoc Bao Ly, Gootam, Praveen, Jaruga, Ewa, Ma, Quangwei, Gnarra, James, Rayford, Walter
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; cyclin-dependent kinase inhibitors; Medical sciences; Nephrology. Urinary tract diseases; PC-3; prostate cancer DU-145 LNCaP; prostate cancer DU‐145 LNCaP, PC‐3; Tumors of the urinary system; Urinary tract. Prostate gland
• ISSN: 0270-4137; 1097-0045
• DOI: 10.1002/pros.10124

BACKGROUND Adp27Kip1, a recombinant adenovirus, was evaluated for expression of p27, a cyclin‐dependent kinase inhibitor (CDKI) and tumor suppressor protein, in human prostate carcinoma cells. Effects of p27Kip1 on cell cycle and apoptosis were analyzed. METHODS We evaluated the effects of overexpression of p27Kip1 in the human prostate carcinoma cell lines LNCaP, DU‐145, and PC‐3 in vitro and in vivo. Growth curve studies, cell cycle analysis, terminal deoxynucleotidyl transferase‐mediated nick end‐labeling (TUNEL), and annexin V–fluorescein isothiocyanate apoptosis analyses were conducted to determine effects of p27Kip1 on cell cycle. CDKI activity assays and Westerns blots were conducted to determine presence/activities of CDKIs. RESULTS Adp27Kip1‐induced protein levels increased in a dose‐dependent manner; p27Kip1 protein was detected within 6 hr of infection with Adp27Kip1 and remained stable for at least 48 hr. The activities of Cdk2, Cdk4, and Cdc2 kinases were inhibited 24 hr after infection with Adp27Kip1. Bromodeoxyuridine incorporation demonstrated a dose‐dependent decrease in S‐phase cells 24 hr postinfection. TUNEL analysis revealed an induction of apoptosis (10 pfu/cell) within 48 hr of infection in all cell lines. Growth curve analyses demonstrated that Adp27Kip1 infection inhibited proliferation of all cell lines tested and decreased cell numbers for Adp27Kip1‐infected LNCaP and PC‐3 cells by 96 hr. Cell cycle analysis of DNA content demonstrated an accumulation of cells in G0/G1‐phase 24–120 hr after Adp27Kip1‐infection. In vivo studies demonstrated a reduction in LNCaP xenograft tumor growth rates in mice injected with Adp27Kip1. CONCLUSION Exogenous p27Kip1 overexpression results in cell cycle regulation in the human prostate carcinoma cell lines tested, representing the first use of this vector on prostate cancer cell lines in vitro and in vivo. Moreover, p27Kip1 expression is associated with an increase in early apoptosis, which represents a recently discovered function for this protein. It also represents the first time this association has been observed in prostate carcinoma cell lines. This study provides support for the further development of Adp27Kip1 as a potential therapeutic vector in the treatment of adenocarcinoma of the prostate. Prostate 53: 77–87, 2002. © 2002 Wiley‐Liss, Inc.