Peng Du1, Lin Ye2, Yong Yang3, Wen G Jiang4. 1. Key laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Urology, Peking University Cancer Hospital & Institute, Beijing, P.R. China. 2. Cardiff University-Peking University Cancer Institute, Cardiff University School of Medicine, Cardiff, U.K. 3. Key laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Urology, Peking University Cancer Hospital & Institute, Beijing, P.R. China yoya_urology@sina.com jiangw@cf.ac.uk. 4. Cardiff University-Peking University Cancer Institute, Cardiff University School of Medicine, Cardiff, U.K. yoya_urology@sina.com jiangw@cf.ac.uk.
Abstract
BACKGROUND: Growth and differentiation factor-9 (GDF9) is a member of the bone morphogentic protein (BMP) family. GDF9 was recently shown to be a regulator of the development and spread of cancer cells, including kidney cancer cells. However, the clinical implication of GDF9 in human clear-cell renal cell carcinoma (CCRCC) remains unknown. In the present study, the expression of GDF9 in human CCRCC tissues, and correlation between GDF9 and pathological grade and stage of the tumours were examined in CRCC specimens. MATERIALS AND METHODS: The expression of GDF9 was examined in paired human normal renal and CCRCC tumour tissues (n=86). The expression of GDF9 in human renal tissues was assessed at both the mRNA and protein levels using reverse transcription-polymerase chain reaction and western blot. Furthermore, the survival curve was constructed using Kaplan-Meier method. RESULTS: Decreased GDF9 protein levels were seen in CCRCC tissues compared with normal tissues. Low protein levels were seen in tumours with high clinical stages and with high pathological nuclear grade of CCRCC. Likewise, levels of GDF9 transcript in normal renal specimens was significantly higher than that in CCRCC tissues. The transcript levels of GDF9 differed significantly amongst different clinical stages and different pathological nuclear grade of CCRCC: The higher the clinical stage or pathological nuclear grade of CCRCC, the lower the transcript level of GDF9. Cumulative survival curves indicated that GDF9 mRNA expression was negatively correlated with cumulative survival time. Patients with high level of GDF9 had significantly longer survival time than the patients with low level of GDF9 (p<0.001). CONCLUSION: GDF9 expression is markedly decreased in CCRCC, and is linked to pathological grade, clinical stage and long-term survival of the patients. This suggests that GDF9 is a potential tumour suppressor in CCRCC. Copyright
BACKGROUND:Growth and differentiation factor-9 (GDF9) is a member of the bone morphogentic protein (BMP) family. GDF9 was recently shown to be a regulator of the development and spread of cancer cells, including kidney cancer cells. However, the clinical implication of GDF9 in humanclear-cell renal cell carcinoma (CCRCC) remains unknown. In the present study, the expression of GDF9 in human CCRCC tissues, and correlation between GDF9 and pathological grade and stage of the tumours were examined in CRCC specimens. MATERIALS AND METHODS: The expression of GDF9 was examined in paired human normal renal and CCRCC tumour tissues (n=86). The expression of GDF9 in human renal tissues was assessed at both the mRNA and protein levels using reverse transcription-polymerase chain reaction and western blot. Furthermore, the survival curve was constructed using Kaplan-Meier method. RESULTS: Decreased GDF9 protein levels were seen in CCRCC tissues compared with normal tissues. Low protein levels were seen in tumours with high clinical stages and with high pathological nuclear grade of CCRCC. Likewise, levels of GDF9 transcript in normal renal specimens was significantly higher than that in CCRCC tissues. The transcript levels of GDF9 differed significantly amongst different clinical stages and different pathological nuclear grade of CCRCC: The higher the clinical stage or pathological nuclear grade of CCRCC, the lower the transcript level of GDF9. Cumulative survival curves indicated that GDF9 mRNA expression was negatively correlated with cumulative survival time. Patients with high level of GDF9 had significantly longer survival time than the patients with low level of GDF9 (p<0.001). CONCLUSION:GDF9 expression is markedly decreased in CCRCC, and is linked to pathological grade, clinical stage and long-term survival of the patients. This suggests that GDF9 is a potential tumour suppressor in CCRCC. Copyright