排序方式: 共有1条查询结果,搜索用时 0 毫秒
1
1.
Becker Roger; Luthgens Birgit; Oesch Franz; Dienes Hans-Peter; Steinberg ablo 《Carcinogenesis》1996,17(12):2635-2640
In order to test the controversially discussed hypothesis thatoval cells are part of a liver stem cell compartment and cangive rise to cholangiocellular as well as hepatocellular carcinomasin the course of liver carcinogenesis, we trans-fected an ovalcell line established in our laboratory with an oncogenicallyactivated genomic Ha-ras clone (pUC EJ 6.6), carrying a valineat position 12 instead of the wild-type glycine, or a rat p53cDNA mutated by site-directed mutagenes is at codon 247, whichcorresponds to codon 249 in the human p53. This codon is ofparticular interest since it represents a mutation hotspot observedin hepatocellular carcinoma especially in regions with highaflatoxin B1 exposure. Independent Ha-rasVal112Wain and p53Ser247recombinant clones were subcutaneously injected into syngeneicnewborn rats and the resulting tumours were analysed histopathologically.Each of two p53Ser247 clones gave negligible tumour yields (onetumour out of 13 injected animals), whereas each of two Ha-rasVal12clones gave marked tumour yields (four tumours out of 13 andseven out of 12 treated animals, respectively). In addition,the p53Ser247-induced tumours appeared only after 11 monthsand were small, whereas the Ha-ras-induced tumours appearedalready after 68 weeks and grew rapidly. Histopathologicalanalysis of the tumours revealed only undifferentiated carcinomas.Interestingly, one tumour that arose upon injection of Ha-rasVal12-transfectedcells stained positive for albumin, showing at least a partialhepatocytic differentiation. 相似文献
1