Objective:To investigate the relationship between poly(ADP-ribose)polymerase(PARP) inhibition and the growth activity of murine colon carcinoma CT26 cell lines in vitro.Methods:The murine colon carcinoma CT26 cell lines were treated with PARP inhibitior 5-AIQ in vitro.MTT assay was used to determine the growth activity of CT26 cells.The expressions of PARP and NF-κB p65 in the nuclei of CT26 cells were investigated by double labelling immunofluorescence and laser scanning cofocal microscope.Results:The inhibitory rates of the growth in 5-AIQ-treated colon carcinoma CT26 cell groups were 17.52%、27.63% and 39.93%

respectively.The inhibitory rate increased with the raising of the 5-AIQ concentration(0.1mmol/L

0.5mmol/L

and1.0mmol/L)

and the difference was significant(P<0.05).There was a co-expression and positive correlation of PARP and NF-κBp65 in the nuclei of colon carcinoma CT26 cells(P<0.05).The expressions of PARP and NF-κB p65 were attenuated in 5-AIQ-treated CT26 cell groups

and the correlation of PARP and NF-κB p65 was also positive(P<0.05).Conclusion:PARP inhibitior 5-AIQ can inhibit the growth activity of colon carcinoma CT26 cells in vitro

and this may be through inhibiting PARP to reduce the activity of NF-κB.PARP may play an important role in the proliferation of colon carcinoma.