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Background: Adp27(Kip1), 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 p27(Kip1) on cell cycle and apoptosis were analyzed., Methods: We evaluated the effects of overexpression of p27(Kip1) 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 p27(Kip1) on cell cycle. CDKI activity assays and Western blots were conducted to determine presence/activities of CDKIs., Results: Adp27(Kip1)-induced protein levels increased in a dose-dependent manner; p27(Kip1) protein was detected within 6 hr of infection with Adp27(Kip1) and remained stable for at least 48 hr. The activities of Cdk2, Cdk4, and Cdc2 kinases were inhibited 24 hr after infection with Adp27(Kip1). 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 Adp27(Kip1) infection inhibited proliferation of all cell lines tested and decreased cell numbers for Adp27(Kip1)-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 Adp27(Kip1)-infection. In vivo studies demonstrated a reduction in LNCaP xenograft tumor growth rates in mice injected with Adp27(Kip1)., Conclusion: Exogenous p27(Kip1) 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, p27(Kip1) 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 Adp27(Kip1) as a potential therapeutic vector in the treatment of adenocarcinoma of the prostate., (Copyright 2002 Wiley-Liss, Inc.)

Purpose: We evaluated the effects of the over expression of p27Kip1, a cyclin dependent kinase inhibitor and tumor suppressor protein, on the 786-0 human renal carcinoma cell line., Materials and Methods: The recombinant adenovirus Adp27Kip1 was evaluated for the induction of p27 protein expression in 786-0 renal carcinoma cells. Expression time and optimal vector concentration were determined. Growth curve studies, cell cycle analysis and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling were done to determine the effects of p27Kip1 on the cell cycle. Cyclin dependent protein kinase (Cdk) inhibitor (CDKI) activity assays were done to determine the expression/activities of Cdks and Western blot analysis was performed to determine the presence of CDKIs and other cell cycle regulator proteins. Nude mouse xenografts were established to demonstrate the in vivo efficacy of Adp27Kip1., Results: p27Kip1 protein expression was detected within 12 hours after Adp27Kip1 infection and it remained stable for at least 48 hours. Growth studies demonstrated that Adp27Kip1 infection resulted in the inhibition of proliferation by 3 days after infection and cell death was detected by day 5. Cell cycle analysis of DNA content indicated an accumulation of cells in the G1 phase of Adp27Kip1 infected cells and a corresponding decrease in S phase cells within 48 hours after infection. Cdk activity was determined, and Cdk2, Cdk4 and Cdc2 kinase activities were inhibited, consistent with p27Kip1 over expression. The levels of the CDKIs p16 and p18 were elevated 24 hours after Adp27Kip1 infection, while p21 levels remained unchanged. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling revealed that Adp27Kip1 infection but not infection by control virus induced detectable apoptosis within 24 hours. Adp27Kip1 significantly caused the reduction in the size of tumors of the renal cell carcinoma xenografts., Conclusions: This study demonstrates the potential effectiveness of Adp27Kip1 as a vector for gene therapy studies of renal cell carcinoma.