Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Reduced expression of SMAD4 in gliomas correlates with progression and survival of patients | He et al. Journal of Experimental Clinical Cancer Research 2011 30 70 http content 30 1 70 Journal of Experimental Clinical Cancer Research RESEARCH Open Access Reduced expression of SMAD4 in gliomas correlates with progression and survival of patients Shi-ming He Zhen-wei Zhao Yuan Wang Ji-pei Zhao Liang Wang Fang Hou and Guo-dong Gao Abstract Background To examine the expression of SMAD4 at gene and protein levels in glioma samples with different WHO grades and its association with survival. Methods Two hundreds fifty-two glioma specimens and 42 normal control tissues were collected. Immunochemistry assay quantitative real-time PCR and Western blot analysis were carried out to investigate the expression of SMAD4. Kaplan-Meier method and Cox s proportional hazards model were used in survival analysis. Results Immunohistochemistry showed that SMAD4 expression was decreased in glioma. SMAD4 mRNA and protein levels were both lower in glioma compared to control on real-time PCR and Western blot analysis both P . In addition its expression levels decrease from grade I to grade IV glioma according to the results of realtime PCR immunohistochemistry analysis and Western blot. Moreover the survival rate of SMAD4-positive patients was higher than that of SMAD4-negative patients. We further confirmed that the loss of SMAD4 was a significant and independent prognostic indicator in glioma by multivariate analysis. Conclusions Our data provides convincing evidence for the first time that the reduced expression of SMAD4 at gene and protein levels is correlated with poor outcome in patients with glioma. SMAD4 may play an inhibitive role during the development of glioma and may be a potential prognosis predictor of glioma. Keywords glioma SMAD4 Immunochemistry assay Quantitative real-time PCR Western blot analysis prognosis 1. Introduction Human gliomas are the most common primary intracranial tumors in adults. A grading scheme proposed by the WHO .