The changes of carbamyl phosphate synthetase I(CPS 1)in diethylnitrosamine-(DEN)-inducedenzyme-altered liver cells were studied by means of immunohistochemical(PAP)and in situcDNA-mRNA hybridization methods.The experi...The changes of carbamyl phosphate synthetase I(CPS 1)in diethylnitrosamine-(DEN)-inducedenzyme-altered liver cells were studied by means of immunohistochemical(PAP)and in situcDNA-mRNA hybridization methods.The experimental rats were treated with DEN,2-acetylaminofluorene(2-AAF)and 2/3 hepatectomy according to Solt-Farber’s protocol andwere further promoted by oral daily administration of 0.05% phenobarbital in drinking water.The results showed that the average number of lesions showing abnormal expression of CPS1 was relatively constant over the course of the experiment(8 months),while the numberof normally expressing lesions gradually decreased.The former lesions were also largerin volume than the latter ones.We conclude that in DEN-initiated lesions the abnormallyexpressed CPS 1 lesions may grow continuously,thus leading to the formation of largernodules.We also suspect that some of these lesions have increased tendencies to developinto tumors.展开更多
The aberrant expression of oncogenes in quality and quantity contributes to carcinogenesis. It depends greatly on many stages, such as transcription, post transciption and translation. The regulation of transcription ...The aberrant expression of oncogenes in quality and quantity contributes to carcinogenesis. It depends greatly on many stages, such as transcription, post transciption and translation. The regulation of transcription plays the most important role in gene regulation. Thus, it has been considered that the research of positive and negative regulators for the transcription regulation, narticularly in suppressors is very important,展开更多
The c-ras and its product P21 have been shown to play an important role in the initiation and development of some malignancies. The activation of c-ras may be associated with two mechanisms: (ⅰ) a point mutation of t...The c-ras and its product P21 have been shown to play an important role in the initiation and development of some malignancies. The activation of c-ras may be associated with two mechanisms: (ⅰ) a point mutation of the codon at position 12 or 61 of the genome leading to a single amino acid alteration in the corresponding product P21; (ⅱ) enhanced expression of ras family encode proteins with展开更多
文摘The changes of carbamyl phosphate synthetase I(CPS 1)in diethylnitrosamine-(DEN)-inducedenzyme-altered liver cells were studied by means of immunohistochemical(PAP)and in situcDNA-mRNA hybridization methods.The experimental rats were treated with DEN,2-acetylaminofluorene(2-AAF)and 2/3 hepatectomy according to Solt-Farber’s protocol andwere further promoted by oral daily administration of 0.05% phenobarbital in drinking water.The results showed that the average number of lesions showing abnormal expression of CPS1 was relatively constant over the course of the experiment(8 months),while the numberof normally expressing lesions gradually decreased.The former lesions were also largerin volume than the latter ones.We conclude that in DEN-initiated lesions the abnormallyexpressed CPS 1 lesions may grow continuously,thus leading to the formation of largernodules.We also suspect that some of these lesions have increased tendencies to developinto tumors.
基金Project supported by the National Natural Science Foundation of China.
文摘The aberrant expression of oncogenes in quality and quantity contributes to carcinogenesis. It depends greatly on many stages, such as transcription, post transciption and translation. The regulation of transcription plays the most important role in gene regulation. Thus, it has been considered that the research of positive and negative regulators for the transcription regulation, narticularly in suppressors is very important,
文摘The c-ras and its product P21 have been shown to play an important role in the initiation and development of some malignancies. The activation of c-ras may be associated with two mechanisms: (ⅰ) a point mutation of the codon at position 12 or 61 of the genome leading to a single amino acid alteration in the corresponding product P21; (ⅱ) enhanced expression of ras family encode proteins with
