Expression of cell-cycle mediators in ovarian cancer cells after transfection with p16(INK4a), p21(WAF1/Cip-1), and p53.
OBJECTIVE
The purpose of this study was to determine whether transfection of ovarian cancer cell lines with recombinant adenoviral vectors containing wild-type p16(INK4a), p21(WAF1/Cip-1), and p53 caused growth inhibition and induction of apoptosis. We also measured the expression of the cell-cycle mediators Bax, Bcl-2, pRb, and mdm-2.


METHODS
We introduced the wild-type p16(INK4a), p21(WAF1/Cip-1), and p53 genes into the ovarian cancer cell lines SK-OV-3 (p16(INK4a) and p53 null) and OVCA-420 (p16(INK4a) and p53 wild-type) by adenoviral transfection. Cell growth inhibition was measured over a 10-day period. Induction of apoptosis was tested for both cell lines 48 h after cell transfection. Expression of cell-cycle mediators was evaluated by Western blot analysis and densitometry.


RESULTS
Growth inhibition was documented after transfection with p16(INK4a), p21(WAF1/Cip-1), and p53 in both SK-OV-3 cells and OVCA-420 cells. Apoptosis was greatest in SKOV-3 cells after transfection with p53. A significant expression of Bax was only seen in the SKOV-3 cells transfected with p53. The bcl-2 protein was poorly expressed in both cell lines. Expression of pRb was suppressed in OVCA-420 cells transfected with p16(INK4a) and p21(WAF1/Cip-1). Infection with Adp16(INK4a) and Adp53 led to an increase in the level of mdm-2 in the SK-OV-3 cell line only.


CONCLUSIONS
In the ovarian cancer cell lines studied, cell growth was inhibited after transfection with p16(INK4a), p21(WAF1/Cip-1), and p53. Cell cycle arrest was highest with p53 transfection. The expression of pro-apoptosis proteins was primarily a function of p53 expression.
Ramirez
P T
PT
Department of Gynecologic Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Gershenson
D M
DM
Tortolero-Luna
G
G
Ramondetta
L M
LM
Fightmaster
D
D
Wharton
J T
JT
Wolf
J K
JK
D017209:Apoptosis / Q000235:genetics; D002453:Cell Cycle / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000096:biosynthesis / Q000235:genetics*; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D016158:Genes, p53 / Q000235:genetics*; D006801:Humans; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000235:genetics; D051028:bcl-2-Associated X Protein
C494826:BAX protein, human; C493956:CDKN1A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein