Involvement of intracellular signaling factors in the serum-enhanced Ca2+-binding protein regucalcin mRNA expression in the cloned rat hepatoma cells (H4-II-E)

✍ Scribed by Masayoshi Yamaguchi; Michiko Nakajima

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 126 KB
• Volume: 74
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/(sici)1097-4644(19990701)74:1<81::aid-jcb9>3.0.co;2-3

✦ Synopsis

The involvement of signaling factors, which are related to serum component, on the regucalcin mRNA expression in the cloned rat hepatoma cells (H4-II-E) was investigated. The change in regucalcin mRNA levels was analyzed by Northern blotting using rat liver regucalcin complementary DNA (0.9 kb of open reading frame). H4-II-E cells were cultured for 2 or 6 h in a medium containing various reagents in the presence of serum (10% fetal bovine serum) after the subconfluent with 3-day-culture. The regucalcin mRNA expression was significantly increased by serum addition. This increase was clearly inhibited by the presence of EGTA (10 Ϫ3 M), A23187 (10 Ϫ6 M), trifluoperazine (10 Ϫ5 M), staurosporine (10 Ϫ7 M), or genistein (10 Ϫ5 M) with 6-h-culture, although the ␤-actin mRNA expression was not altered by the reagents. Meanwhile, the regucalcin mRNA expression was significantly stimulated by the addition of Bay K 8644 (2.5 ϫ 10 Ϫ6 M) in the presence of serum. This effect was also seen in the presence of genistein (10 Ϫ5 M). The present study suggests that the regucalcin mRNA expression is mediated through signaling pathways which are partly involved in Ca 2ϩ -dependent protein kinases and tyrosine kinase in H4-II-E hepatoma cells.