RESUMO
Protein P1, which is a nuclear protein resembling high mobility group proteins, has been studied in human breast adenocarcinomas and compared to those from control tissue. The presence of the protein was confirmed by in vitro phosphorylation by casein kinase II and immunoblotting, using antibodies raised in rabbits against rat liver P1. The protein has been isolated by reverse phase HPLC chromatography which provides a more rapid method of purification requiring smaller amounts of material. The levels of P1 expression were investigated and it was found that there was a three-fold increase in the ratio of P1/histone H1 in normal breast tissue as compared to the neoplastic tissue. In two other malignant and non-malignant tissues studied, the level of P1 was also decreased in the malignant tissues. Thermolytic phosphopeptides of P1 from normal and malignant human breast tissues exhibited the same pattern, though when compared to the phosphopeptide pattern from rat tissue, differences were observed.
Assuntos
Adenocarcinoma/metabolismo , Neoplasias da Mama/metabolismo , Proteínas de Grupo de Alta Mobilidade/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição , Aminoácidos/análise , Animais , Western Blotting , Caseína Quinase II , Proteínas de Ciclo Celular , Cromatografia Líquida de Alta Pressão/métodos , Proteínas de Ligação a DNA/metabolismo , Densitometria , Eletroforese em Gel de Poliacrilamida , Feminino , Células HeLa , Proteínas de Grupo de Alta Mobilidade/química , Proteínas de Grupo de Alta Mobilidade/isolamento & purificação , Histonas/análise , Humanos , Processamento de Imagem Assistida por Computador , Técnicas In Vitro , Componente 3 do Complexo de Manutenção de Minicromossomo , Peso Molecular , Proteínas Nucleares/química , Proteínas Nucleares/isolamento & purificação , Fosfopeptídeos/análise , Fosforilação/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , CoelhosRESUMO
The High Mobility Group protein HMG 17 has been isolated from human leukemia cells obtained from patients with chronic myelogenic leukemia (CML). The level of expression of HMG 17 was investigated Human leukemia cells have three times more HMG 17 than normal human leukocytes. Three other malignant tissues were also compared. Two of these breast adenocarcinoma and other intestine- also exhibit higher amounts of HMG 17. The elevated expression of HMG 17 suggests that the level of the protein may be associated with rates of cellular proliferation.
Assuntos
Proteínas de Grupo de Alta Mobilidade/sangue , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Leucócitos/metabolismo , Aminoácidos/análise , Animais , Bovinos , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Proteínas de Grupo de Alta Mobilidade/biossíntese , Proteínas de Grupo de Alta Mobilidade/isolamento & purificação , Humanos , Peso Molecular , Valores de Referência , Timo/metabolismoRESUMO
The effect of chlorambucil, a bisalkylating agent, on the biosynthesis of the 5% PCA extractable protein fraction of the cancer cell line, HEp-2, has been analyzed. It was found that the synthesis of all the high mobility group proteins as well as that of the H1 and H1o histone proteins are inhibited by this agent. HMG 14 and the H1, H1o proteins are inhibited to the same extent as that reported for the core histones of the same cell line [7], while slightly higher levels of inhibition were found for the HMG 1, 2 and 17 proteins. The proteins, P1 and HMG I exhibited the highest level of inhibition of the entire fraction. These findings extend previous findings regarding the histone proteins and may be correlated to a dysfunction in the normal process of chromatin condensation and a potential cytotoxic effect of this agent during the G2 phase.