NOVEL SMOOTH-MUSCLE CELL-LINES FROM TRANSGENIC MICE HARBORING TEMPERATURE-SENSITIVE SV40 LARGE T-ANTIGEN GENE - TEMPERATURE-DEPENDENT EXPRESSION OF SMOOTH-MUSCLE MYOSIN HEAVY CHAIN-1 AND CALPONIN GENES

We have established novel vascular smooth muscle cell lines (SVS30 and SVS24 cells) which retain the expression of specific markers for smoo th muscle cells, such as alpha-actin, smooth muscle myosin heavy chain -1, and calponin, from transgenic mice harboring the temperature-sensi tive SV40 large T-antigen gene, SVS cell lines showed temperature-depe ndent growth and the expression of SV40 large T-antigen, Interestingly , protein and mRNA levels of smooth muscle myosin heavy chain-1 and ca lponin seen in culture at the non-permissive temperature (39 degrees C ) were higher than those at the permissive temperature (33 degrees C), These results suggest that SV40 large T-antigen affects the expressio n of smooth muscle-specific markers in SVS cell lines, and that some o f the characters in SVS cell lines can be controlled by culture temper ature. SVS cell lines should be quite valuable tools with which to stu dy the regulation of phenotypic modulation of smooth muscle cells, and to identify smooth muscle specific transcription factors which involv e the expression of smooth muscle myosin heavy chain-1 and calponin ge nes. (C) 1997 Academic Press Limited.