Objective: To investigate the joint therapeutic effect of Liuwei Dihuangwan (LD) combined with hepatocarcinoma HSV-tk/GCV suicide gene on the exp ression of connexin (Cx)

clarity the therapeutic mechanism of LD. Method: Ninety Kunming mice were randomized into 4 groups:model group

LD group (10 g ·kg-1 ·d-1)

suicide gene therapy group (intraperitoneal injection of guanosine ganciclovior) and the combined group.The transplanted tumor mice model of H22 hepatocarcinoma was established by subcutaneous inoculation of H22 and H22/tk cells.We selected the tumor tissue of hepatocarcinoma tumor-bearing mice for conventional preparation

carried out biopsy of DAB immunohistochemical staining

and used the SABC immunohistochemical assay to detect the expression of Cx26

Cx43

Cx32. Result: The positive expression was found in cytoplasm and cell membrane under the microscope. Cx43 expression appeared in tumor adjacent tissues

especially where infiltrated by fibrous tissue had strongly positive expression

but cancer cells in the tumor nodules had relatively weak expression. We found the expression of Cx26 and Cx32 were in tumor cell

especially near the tumor tissues where infiltrated by adipose tissue showed strong positive expression. The expression of connexin in LDB treatment group and suicide gene therapy combined with LD treatment group was obviously stronger than that in tumor model group. The differences of expression of Cx between suicide gene therapy combined with LDB treatment group and showed statistical significance (P<0.05). Conclusion: Suicide gene therapy combined with LD in treatment group can significantly improve the expression of Cx26

Cx43

Cx32

especially Cx32.It indicates that the enhancing effect of LD on suicide gene bystander is related to gap junction.