Objective    To explore the regulation mechanism of cyclin D

2

under trichostatin A (TSA) treatment.      Methods    The mRNA level of cyclin D

2

was detected by RT-PCR. Cyclin D

2

promoter fragment was amplified by high-fidelity PCR with A549 cell genome DNA as a template

and was then inserted into plasmid vector pGL3-BASIC. Truncated promoter fragments were amplified based on the recombinant plasmid. The relative activity of the promoter fragments was evaluated with the firefly luciferase reporter gene method.     Re

sults    The mRNA level of cyclin D

2

increased under TSA treatment. Four plasmids carrying the truncated cyclin D

2

promoter fragments to control reporter gene expression were constructed and named pGL3-1816CD2-LUC

pGL3-1358CD2-LUC

pGL3-720CD2-LUC and pGL3-524CD2-LUC. Under TSA treatment

the promoter activity diminished when the promoter fragment was truncated to  524 bp.     Conclusion    The mRNA level increase of cyclin D

2

depends on the promoter under TSA treatment. The TSA response region in cyclin D

2

promoter is located in the range from  720 bp to  524 bp.