RESUMO
The Period2 (Per2) gene is an essential component of the mammalian circadian clock and is strongly linked to glioma occurrence and its response to radiotherapy. Here, we examined the role of Per2 in the response to X-ray-induced DNA damage in U343 glioma cells and in a mouse cancer model. Following low dose X-ray irradiation, we observed that lowering Per2 expression using RNAi reduces DNA damage and cell death in U343 cells and glioma tissue. Additionally, Per2 was associated with increased TP53 activity and was involved in the DNA damage during TP53-mediated apoptosis. These findings suggest that Per2, a core circadian gene, is not only a tumor suppressor gene but can also be regarded as an upstream regulator of TP53. It thus appears that Per2 is an important inhibitor of tumor growth that acts by increasing TP53 expression, DNA damage repair, and apoptosis.
Assuntos
Apoptose/genética , Regulação para Baixo , Glioma/genética , Proteínas Circadianas Period/genética , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteína Supressora de Tumor p53/genética , Animais , Linhagem Celular Tumoral , Dano ao DNA , Reparo do DNA/genética , Glioma/metabolismo , Glioma/patologia , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Circadianas Period/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Interferência de RNA , Transdução de Sinais/genética , Transplante Heterólogo , Proteína Supressora de Tumor p53/metabolismo , Raios XRESUMO
Objective To detect the expressions of COX-2 and VEGF-C in breast cancer and to explore the relationship between their expressions and lymphatic metastasis. Methods Immunohistochemical stai- ning (SABC) was used to detect the expressions of COX-2 and VEGF-C proteins in 60 cases of breast canc- er. Results The positive rate of COX-2 and VEGF-C in breast cancer were 66.7% and 60. 0%, and the expression of COX-2 was positively correlated with VEGF-C (r =0.429, P<0.05). COX-2 and VEGF-C expressions were positively correlated with lymphatic metastasis (P<0.05). The lymphatic metastasis rate in the positive group of COX-2 and VEGF-C were higher than that in the negative group of COX-2 and VEGF-C. Conclusion Over expression of COX-2 and VEGF-C were observed in breast cancer, and closely related to lymphatic metastasis. COX-2 has positive correlation with VEGF-C and was correlated with lym- phatic metastasis of breast cancer. COX-2 may promote the over expression of VEGF-C in tumor cells and cause lymphatic metastasis.
RESUMO
Objective: To explore the problem behaviors of high school students and its distribution among them. Methods: 1 739 middle school students in Beijing were collected as our sample (N=1739). Anonymous questionnaire of problem behavior of adolescents were used in this investigation. Results:1) the problem behaviors (general delinquency, cigarette smoking, and problem drinking) were significantly correlated with each other (r=0.28, 0.37, 0.39,P