[Inhibition of in vivo growth of lung carcinoma cells after transfection with gap junction gene Cx43].

OBJECTIVE

To explore the effects of expression of gap junction gene and cell-cell communication on tumor growth.

METHODS

A highly metastatic human lung carcinoma cell line PG was used. PG cells were defective of gap junctional intercellular communication(GJIC) and lacking expression of gap junction gene Cx43. By transfection, Cx43 cDNA was introduced into PG cells and blank vector cDNA was used as mock control. By using Northern-blot, dye-transfer methods and examinations of in vitro/in vivo growth, stable Cx43 transfectant cells were studied.

RESULTS

The mock control cells resembled untransfected PG cells in lacking expression of Cx43 and GJIC function. They grew fast in soft agar(colony formation rate 11.6%) and in nude mice (average tumor weight 3.47 g in 28 days). The Cx43 transfectant cells showed increased level of Cx43 mRNA and increased function of GJIC. Cell growth in soft agar and in nude mice was markedly retarded. The inhibition rate was 90% and 75%, respectively.

CONCLUSION

Increased expression of gap junction gene Cx43 induced tumor-suppressing effects in human lung carcinoma cells.