OBJECTIVETo elucidate the potential molecular mechanism responsible for the early time of tumor promotion, gene expression profile was studied in the transformed BALB/c 3T3 cells induced by 12-O-tetradecanoylphorbol-13-acetate (TPA).

METHODSThe two-stage cell transformation model was established by using the initiator of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and promoter of TPA. Cell proliferation was measured by trypan blue staining and cell cycle analysis was carried out by flow cytometry assay. A cDNA microarray representing 1 152 genes was used to investigate the gene expression profiles of BALB/c 3T3 cells exposed to TPA at 4 h and 24 h respectively.

RESULTSTPA could effectively inhibit cell proliferation and induce the G1 and S cell cycle arrested in the early time. Moreover 19 genes were found differentially expressed at least twofold in the TPA treated cells as compared with the control cells, 9 of them were upregulated and 10 downregulated. Most of the differentially expressed genes were involved in cell proliferation, differentiation or apoptosis, and related to ras or p53 signal transduction pathway.

CONCLUSIONTPA could influence the transcriptional expression of some genes related to cell cycle modulation and ultimately result in the cell growth arrest.