RESUMEN
<p><b>OBJECTIVE</b>To investigate the genes involved in pulmonary metastasis of human fibrosarcoma HT1080 cells in nude mice.</p><p><b>METHODS</b>HT1080 cells were injected into the tail vein of BALB/ C nude mice. RNA samples were extracted from pulmonary metastatic tissues and normal control lung tissues, purified using Atlas Pure Total RNA labeling System (Clonetech Laboratories). cDNA probes labeled with 32P were prepared and hybridized to a cDNA membrane constructed with spots of 1176 human cancer related genes and radioactivities on the membrane were measeured by BAS 5000. The mRNA expression of gene FN1 was determined by real time RT-PCR using TaqMan methods. Furthermore, cells with FN1 expression were localized and obtained in situ in pulmonary metastatic foci by laser captured microdissection, and the FN1 expression was quantitated by real time RT-PCR.</p><p><b>RESULTS</b>Of the total 1176 genes, 27 genes (2. 3%) revealed to be apparently up-regulated and 4 genes (0. 3% ) down-regulated. Real time RT-PCR analysis verified significant up-regulation of gene FN1. Laser captured microdissection/ real time RT-PCR analysis demonstrated up-regulated gene FN1 not in stroma cells but in tumor cell nests.</p><p><b>CONCLUSION</b>Gene FN1 expression in fibrosarcoma HT1080 cells may be involved in pulmonary metastasis.</p>