BACKGROUNDTo isolate and identify the genes related to cancer metastasis by comparison of two cell strains with different metastasis potentials subcloned from human lung giant cell carcinoma cell line.

METHODSSuppression subtractive hybridization (SSH) was used to compare the levels of gene expression between the two cell strains and SSH library was constructed. After screening the library by gene chip, the expressed sequence tags (ESTs) with different expressing level were sequenced and blasted with GenBank.

RESULTSSeventy-nine genes were obtained that were expressed much higher in PLA-801D than in PLA-801C, including two full-length cDNA. GenBank Accession numbers of the two cDNA, named MAG-1 and MAG-2, were BC006236 and BC002420, the 8.5 kb MAG-1 gene was composed of four exons and located on the chromosome of 4q21. The MAG-2 gene, which was made up by 9 exons, had a length of 5.2 kb and its location was 2q35. Both sequences had open reading frames (ORF) and promoters before the theoretical transcription start points. Using special software, the secondary structure of theoretical products of the two cDNAs was prognosticated, α-helix was the main proportion, but β-pleated sheet and random coil were also included.

CONCLUSIONSThe expression of MAG-1 and MAG-2 has significant differences in these two cell strains, so they might impact tumor metastasis in some ways that are still uncharted.