OBJECTIVETo understand the up regulatory mechanism of human REV3 gene induced by the chemical carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG).

METHODSBioinformatic analysis of human REV3 gene promoter region was based on BLAST alignment, promoter prediction software and recognition of transcriptional factor binding sites. Cloning of human REV3 gene promoter region was performed by nested PCR. Response of human REV3 gene promoter to the chemical carcinogen MNNG was measured by transient transfection assay based on the dual luciferase reporter assay system.

RESULTBioinformatic analysis showed that human REV3 gene promoter region was located on chromosome 6 PAC clone RP3-415N12, and that the hypothetical promoter region contained promoter sequences, rich CpG islands, and putative recognition sites for several transcriptional factors, including AP-1/c-Jun/c-Fos, AP-2, STAT, CREBP, and NF-kappaB. Reconstructed reporter plasmid pGL3- 2582 was established by inserting 2582 nucleotides from the promoter region into the luciferase reporter vector pGL3-Basic. Transient transfection assay showed the hypothetical REV3 promoter region had promoter function, and it responded to MNNG treatment (P<0.01).

CONCLUSIONHuman mutator REV3 gene promoter region has been successfully cloned. The response of REV3 promoter region to MNNG suggests that REV3 gene can be regulated at transcriptional level under conditions of genotoxic stress.