Screening for genes involved in tissue invasion based on placenta formation and cancer cell lines with low and high metastatic potential

During the formation of placenta, trophoblast cells vigorously invade maternal uterine tissues, sharing many features with the invasion of cancers. We applied RNA differential display to placenta tissues from 8.5 to 17.5 days post-coitus (dpc) ICR mice, and isolated 188 cDNA fragments expressed differentially. Among the 25 known cDNA fragments thus far analyzed, six cDNAs have been reported to be relevant to tumor invasion and/or metastasis. Furthermore, 11 of 20 unknown cDNAs isolated showed differential expression between the pairs of cancer cell lines with low and high metastatic potential, indicating potential usefulness of the present two-step approach.