Objective: To assess the potential of p21 as a gene therapy treatment for prostate cancer, by introducing p21 into both androgen-dependent (AD) and -independent (AI) human prostate cancer cell lines via a recombinant adenoviral vector, Ad5CMV-p21, carrying human p21 cDNA.
Materials and methods: The LNCaP, DU145 and PC-3 human prostate cancer cell lines were cultured and infected with Ad5CMV-p21. Cell growth, cell-cycle progression and tumorigenicity were then assessed by thymidine incorporation into cellular DNA, and cell number, flow cytometry, and tumour growth after inoculating the cells into nude mice.
Results: Growth was inhibited in Ad5CMV-p21 viral-infected AD and AI prostate cancer cells. The effects were dose-dependent, regardless of the androgen status of the cell lines. Flow cytometric analysis showed that Ad5CMV-p21 arrested cell-cycle progression at G1/S with no appreciable effect on the levels of apoptotic cells. The tumorigenicity of cancer cells infected with Ad5CMV-p21 was greatly reduced in athymic mice.
Conclusions: These results suggest that Ad5CMV-p21 may be a new therapeutic agent for human prostate cancer gene therapy.