Expression Pattern of the Genes for Different Members of the Heat-Shock Protein 70 Family, Ornithine Decarboxylase, and c-Ha-ras During the Early Stages of Hepatocarcinogenesis

✍ Scribed by Lorenza Tacchini; Luisa Schiaffonati; Emilia Rappocciolo; Gaetano Cairo; Aldo Bernelli-Zazzera

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 415 KB
• Volume: 2
• Category: Article
• ISSN: 0899-1987
• DOI: 10.1002/mc.2940020502

✦ Synopsis

Northern blot analysis with specific probes indicates that, in the liver of normotherrnic rats under the carcinogenic regimen of Solt and Farber (Nature 263:701,1976), diethylnitrosamine (DEN), 2-acetylaminofluorene (AAF), and partial hepatectomy (PH), either alone or in combination, do not induce the expression o f the heatshock protein 70 (hsp70) gene family. On the contrary, the inducibility of hsp70 mRNAs in the liver o f heatshocked animals is maintained throughout the treatment, as it is in nodules that are found in the liver 2 weeks posttreatment. The steady-state level o f the constitutive hsp70-related cognate protein (hsc73) mRNA, which is known t o be particularly high in fast-growing cells, increases above the normal level only during liver regeneration, stays at a high level up t o 8 days after hepatectomy, independently of any associated exposure to carcinogenic chemicals, and is practically unchanged in the nodules. Ornithine decarboxylase mRNA increases only in livers of normothermic rats at 16 h of regeneration. The expression of the c-Ha-ras oncogene increases slightly, but steadily, during the carcinogenic treatment and persists at a high level when other changes have subsided.