BACKGROUNDTo explore the effects of transfection of nm23-H1 gene on expression of β-catenin and phospho-β-catenin in human high-metastatic large cell lung cancer line L9981, and to provide evidence to elucidate the molecular mechanism of nm23-H1 mediated tumor metastatic suppression.

METHODSTo determine whether nm23-H1 contributes to cytoplasm and nuclear β-catenin and phospho-β-catenin expression, the expression level of β-catenin and phospho-β-catenin in cytoplasm and nucleus was detected in human high-metastatic large cell lung carcinoma cell lines including primary cell line L9981 with nm23-H1 gene deletion, L9981-nm23-H1 transfected with nm23-H1 gene, and L9981-pLXSN transfected with vector by Western blot.

RESULTS(1)β-catenin expression in L9981-nm23-H1 cytoplasm (IOD) (3 649±118) was significantly higher than that in L9981 (1 401±31) and L9981-pLXSN (1 350±55) cell lines (P < 0.001);(2)There was no statistical diffe-rence of the β-catenin expression in nucleus among L9981-nm23-H1 (2 945±68), L9981 (2 604±23) and L9981-pLXSN (2 652±53) cell lines (P > 0.05);(3)Phospho-β-cetenin expression of cytoplasm in L9981-nm23-H1 cell line (3 123±102) was significantly lower than that in L9981 (4 362±131) and L9981-pLXSN ( 4 500 ±117) cell lines (P < 0.001);(4)Phospho-β-catenin expression of nucleus in L9981-nm23-H1 (5 136±112) was significantly higher than that in L9981 (2 666±116) and L9981-pLXSN (2 661±66) cell lines (P < 0.001);(5)There was no statistical difference of β-catenin or phospho-β-catenin expression in cytoplasm and nucleus between L9981 and L9981-pLXSN cell lines (P > 0.05).

CONCLUSIONS(1)nm23-H1 gene transfection can remarkably upregulates the expression of cytoplasm β-catenin in human high-metastatic large cell lung cancer cell line L9981, but do not induce the nucleus accumulation of β-catenin; (2)Transfection of nm23-H1 gene can significantly upregulate the expression of phospho-β-catenin in nucleus and remarkably downregulate the expression of phospho-β-catenin in cytoplasm of L9981; (3)Regulation of the expression of the key modecule, β-catenin, in Wnt signal pathway might be the important melecular mechanisms which nm23-H1 gene controls "Lung Cancer Metastatic Suppresive Cascade" and reverves cancer metastasis in L9981.