Growth suppression of human ovarian cancer cell lines by the introduction of a p16 gene via a recombinant adenovirus.
OBJECTIVE
The cell cycle regulatory protein p16 (CDKN2/cyclin dependent kinase 4 inhibitor/multiple tumor suppressor-1) causes cell cycle arrest at the G1 checkpoint by inhibiting activity of cyclin D-CDK4 complexes. The purpose of this study is to assess the effect of introduction of the p16 gene into two ovarian cancer cell lines via a recombinant adenoviral vector (Ad5CMV-p16).


METHODS
Cells lines used were SKOV3, which has a p16 deletion, and OVCA420, which has normal p16. Transduction efficiency was established by infecting cells with an adenovirus containing the Escherichia coli beta-galactosidase gene (Ad5CMV-beta-gal) at multiplicity of infection from 0 to 1000 and staining for X-gal. Cells were infected with Ad5CMV-p16 and cell growth was assessed by counting cells every other day for up to 7 days. Western blotting was done to assess for p16 expression after infection. Fluorescence-activated cell sorting after staining with propidium iodide was done to assess the effect of p16 on the cell cycle.


RESULTS
The SKOV3 cell line was transduced with the adenovirus at a slightly lower MOI than the OVCA420 cell line. Growth of the Ad5CMV-p16-infected cells was suppressed 75-80% by cell count in both cell lines and caused morphologic changes of the cells consistent with apoptosis. The p16 protein expression was seen to increase within 24 h after introduction of the p16 gene. G1 arrest of cells occurred beginning 24 h after introduction of the p16 gene.


CONCLUSIONS
These results suggest that Ad5CMV-p16 may be further studied as a potential therapeutic agent for ovarian cancer as introduction of the p16 gene into ovarian cancer cell lines causes a G1 arrest and attenuation of growth, regardless of the endogenous p16 status of the cells.
Wolf
J K
JK
Department of Gynecologic Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, 77030, USA.
Kim
T E
TE
Fightmaster
D
D
Bodurka
D
D
Gershenson
D M
DM
Mills
G
G
Wharton
J T
JT
D000260:Adenoviruses, Human / Q000235:genetics*; D002455:Cell Division; D004274:DNA, Recombinant; D005260:Female; D019942:Genes, p16; D015316:Genetic Therapy; D006801:Humans; D010051:Ovarian Neoplasms / Q000473:pathology* / Q000628:therapy*; D014407:Tumor Cells, Cultured
D004274:DNA, Recombinant