BACKGROUNDScreening metastatic-related genes of lung cancer is helpful to understand the molecular mechanisms of lung cancer invasion and metastasis. In order to screen the differential expression genes related to metastasis of lung cancer, we constructed and preliminarily screened the subtracted cDNA libraries of human large cell lung cancer cell lines with different metastatic potentials in this study.

METHODSSubtracted cDNA library was constructed in the different metastastic potential cell lines NL9980 and L9981 by suppression subtractive hybridization (SSH) method. The positive clones were preliminarily screened by blue-white colony based on the α-complementary principal, and precisely identified by PCR. The forward and reverse subtracted libraries were screened and identified by dot blot to obtain the clones corresponding to differential expression segments.

RESULTSThe subtracted cDNA libraries were successfully constructed in the different metastastic potential cell lines NL9980 and L9981. Three hundred and seven positive clones in the forward subtracted library and 78 positive clones in the reverse subtracted library were obtained by the dot blot method.

CONCLUSIONSSSH is proved to be an efficient tool for differential expression gene cloning. The forward and reverse subtracted cDNA libraries of different metastastic potential cell lines are constructed by this method. The differential expression genes related to tumor metastasis might exist in the human large cell lung cancer cell lines with different metastasis potential.