Your browser doesn't support javascript.
loading
Down-regulation of Chk1/Chk2 gene expression increases apoptosis in irradiated HeLa cells and its mechanism / 中华肿瘤杂志
Chinese Journal of Oncology ; (12): 178-182, 2009.
Artigo em Chinês | WPRIM | ID: wpr-255535
ABSTRACT
<p><b>OBJECTIVE</b>To explore the increasing effect of blocking Chk1 and /or Chk2 gene by Chk1 or Chk2-specific antisense oligodeoxynucleotides (AsODN) on apoptosis in HeLa cell line after irradiation and its mechanism of action.</p><p><b>METHODS</b>Asynchronized HeLa cells were exposed to (60)Co-irradiation at different dosage to activate G(2)/M checkpoint arrest. The cell cycle profiles were observed in HeLa cells after irradiation at a range of various doses and different time points by flow cytometry. In the experimental groups, Chk1/2 sODN and AsODN alone or in combination were transfected into HeLa cells, and the cells were exposed to (60)Co-irradiation at 24 h after transfection. The changes of Chk1/2 protein expression were assayed by Western blot and confocal laser scanning microscopy (Confocal), and the cell cycles, apoptosis rates and cell cycle specific apoptosis were detected by annexin V-PI labeling and flow cytometry.</p><p><b>RESULTS</b>Apoptotic response was significantly increased in the Hela cells after G(2)/M arrest and was inversed to activation of G(2)/M checkpoint. Either Chk1 or Chk2-specific AsODN consistently enhanced DNA damage-induced apoptosis by 90% approximately 120%, compared to corresponding sODN control (P < 0.05). Unexpectedly, combined use of Chk1- and Chk2-specific AsODN did not produce synergistic effect as compared to treatment with Chk1- or Chk2-specific AsODN alone (P > 0.05). While irradiated HeLa cells underwent apoptosis preferentially in G(1)-phase, apoptosis occurred in either of G(1)-, S- or G(2)/M -phase in the presence of Chk1 and/or Chk2 AsODN.</p><p><b>CONCLUSION</b>The radioresistance is mainly induced by activating the cell cycle checkpoint signal transduction pathway after irradiation, and abrogating of the key effector Chk1 and Chk2 may increase the apoptotic sensitivity to irradiation due to changes of the pattern of cell cycle specific apoptosis.</p>
Assuntos
Texto completo: DisponíveL Índice: WPRIM (Pacífico Ocidental) Assunto principal: Proteínas Quinases / Efeitos da Radiação / Células HeLa / Transfecção / Regulação para Baixo / Regulação Neoplásica da Expressão Gênica / Ciclo Celular / Proteínas Serina-Treonina Quinases / Radioisótopos de Cobalto / Apoptose Limite: Humanos Idioma: Chinês Revista: Chinese Journal of Oncology Ano de publicação: 2009 Tipo de documento: Artigo

Similares

MEDLINE

...
LILACS

LIS

Texto completo: DisponíveL Índice: WPRIM (Pacífico Ocidental) Assunto principal: Proteínas Quinases / Efeitos da Radiação / Células HeLa / Transfecção / Regulação para Baixo / Regulação Neoplásica da Expressão Gênica / Ciclo Celular / Proteínas Serina-Treonina Quinases / Radioisótopos de Cobalto / Apoptose Limite: Humanos Idioma: Chinês Revista: Chinese Journal of Oncology Ano de publicação: 2009 Tipo de documento: Artigo