Suppression of synthesis of tropomyosin isoform 2 in metastatic v-Ha-ras-transformed NIH3T3 cells.

We have reported that the synthesis of tropomyosin isoform 2 (TM2) is significantly suppressed in high-metastatic Lewis lung carcinoma cells compared with that in low-metastatic cells. In order to examine whether the change is also observed in other high-metastatic tumor cells, we compared the pattern of expressions of TM isoforms between NIH3T3 cells and v-Ha-ras-transformed NIH3T3 (pH1-3) cells, the latter of which was highly metastatic when injected into BALB/c nude mice. The results showed that the expression of TM2 was less in pH1-3 cells than in NIH3T3 cells, suggesting that the suppression of TM2 synthesis is involved in the expression of metastatic phenotype.