ENHANCED METASTASIS OF B16 MELANOMA-CELLS BY UNEXPECTED ELEVATED EXPRESSION OF THE METASTASIS-ASSOCIATED TI-241 (LRF-1-RELATED, JUN-FOS-RELATED) GENE TREATED WITH ANTISENSE OLIGONUCLEOTIDE

B16-F10 is a B16 mouse melanoma subline that preferentially metastasiz es to the lung following intravenous injection. Previously we isolated TI-241 (LRF-1 homologue related to Jun-Fos) gene that was expressed h igher in the high metastatic clone B16-F10 than the low metastatic clo ne F1. Transfection of TI-241 into F1 converted it into a high-metasta tic cell. We studied the effect of antisense oligonucleotide designed to reduce the expression of TI-241 in B16-F10 cells, and observed an u nexpected increase in the TI-241 level. The increase in the expression was maximal at 30 h, then it decreased during further culture with or without TI-241 antisense oligonucleotide. This increased TI-241 expre ssion by antisense oligonucleotide was also observed in B16-F1 cells w hereas sense oligonucleotide did not affect the expression. B16-F10 ce lls cultured with TI-241 antisense oligonucleotide showed enhanced exp erimental metastatic potential to the mouse lungs compared with untrea ted B16-F10 and B16-F10 cultured with TI-241 sense oligonucleotide. (C ) 1998 Rapid Science Ltd.