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Biomedical subjects

G J Cote

Publications and source records attributed to G J Cote.

57 records · Page 4Linked to original sources

Oncogene expression in rat hepatomas and during hepatocarcinogenesis.

In this study we examined oncogene expression in several Morris hepatomas. We found elevated transcripts for Ha-ras, Ki-ras, and the myc oncogenes, while the src oncogene was not increased. Northern analysis revealed transcript sizes of 1.4 kb for Ha-ras and 2.5 kb for myc. Analysis of primary tumors induced by the carcinogen 3'-methyl-4-dimethylaminoazobenzene (3'-MDAB) showed increasing oncogene transcript production with increasing length of diet. The results show enhanced ras and myc expression in rat hepatocellular carcinomas and during hepatocarcinogenesis.

Animals↗

Tissue specific control of alpha-fetoprotein gene expression.

The expression of the alpha-fetoprotein (AFP) gene was studied in rat liver and kidney. A significant level of AFP mRNA was found in neonatal liver and kidney, but not in adult tissues. Unlike liver the re-expression of AFP mRNA was not seen upon chemically induced regeneration of the kidney. Treatment of neonatal rats with dexamethasone caused a decrease in liver AFP mRNA levels, but a similar decrease was not apparent in kidney. Northern analysis revealed AFP mRNA size to be identical in neonatal liver and kidney. The results suggest different gene regulatory mechanisms in liver and kidney for the AFP gene.

Aging↗

The enhancement of specific gene transcription in isolated nuclei by added HeLa whole cell extract.

Transcription was carried out in isolated rat liver nuclei by endogenous RNA polymerase with the addition of HeLa whole cell extract (HWCE) in the presence of nucleoside 5'-[gamma-S]triphosphate. The resulting 5'-gamma-thiophosphate on the synthesized RNA allows separation of in vitro initiated RNA from bulk RNA by mercury-agarose chromatography. HWCE not only increased initiation of new RNA chains greater than 3 times but also had no effect on the RNA synthesis by RNA polymerase II. The initiation of transcription of albumin and alpha-fetoprotein genes in an isolated nuclei system was selectively enhanced by HWCE. Using this system, we studied the effect of glucocorticoid on albumin and alpha-fetoprotein gene expression in vitro.

Albumins↗