Background SRY-related HMG-box 17 （SOX17） encodes a member of the SOX （SRY-related HMG-box） family of transcription factors involved in the regulation of embryonic development and in the determination of the cell ...Background SRY-related HMG-box 17 （SOX17） encodes a member of the SOX （SRY-related HMG-box） family of transcription factors involved in the regulation of embryonic development and in the determination of the cell fate. Recently, it was considered as a tumor suppressor gene to inhibit canonical Wnt/β-catenin signaling pathway in several malignancies. However, the function of SOX17 in thyroid cancer was unknown. Therefore, we investigated the epigenetic changes and the function of SOX17 in thyroid cancer. Methods The methylation status of the promoter region of SOX17 was detected using methylation-specific PCR in 63 papillary thyroid carcinoma （PTC） tissue, 10 normal thyroid tissue, and two thyroid cancer cell lines. Semi-quantitative RT-PCR was used to assess mRNA expression of SOX17 before and after 5-aza-2＇-deoxycytidine treatment in thyroid cancer cell lines. Expression of SOX17 and β-catenin were detected by immunohistochemistry in PTC and adjacent tissue. Luciferase reporter assay, colony formation, transfection, and Western blotting were employed to analyze the effect of SOX17 on thyroid cancer cell proliferation and the function of SOX17 in the Wnt signal pathway. Results Loss of SOX17 expression was correlated to the promoter region hypermethylation in thyroid cancer cell lines. Re-expression of SOX17 was found in TPC-1 cell line after 5-aza-2＇-deoxycytidine treatment. In primary thyroid cancer, 60.3% （38/63） were methylated and 39.7% （25/63） unmethylated. But no methylation was found in noncancerous thyroid tissues. Methylation of SOX17 was associated reversely with β-catenin expression in the cytoplasm or nucleus significantly in the PTC （P 〈0.05）. Colony formation was inhibited by re-expression of SOX17 in TPC-1 cells. SOX17 suppressed the Wnt signaling pathway and the HMG domain was essential for this effect. Conclusions SOX17 was frequently methylated in human PTC. Loss of SOX17 expression was induced by promoter region hypermethylation. SOX17 inhibited thyroid cancer 展开更多
目的:研究沉默大鼠肾组织中通用控制核苷酸合成5(general control nonderepressible 5,GCN5)基因、性别决定区Y框蛋白9(SRY related HMG box-9,SOX9)基因对Thy-1肾炎(Thy-1 nephritis,Thy-1N)大鼠肾组织内转化生长因子-β1(transforming...目的:研究沉默大鼠肾组织中通用控制核苷酸合成5(general control nonderepressible 5,GCN5)基因、性别决定区Y框蛋白9(SRY related HMG box-9,SOX9)基因对Thy-1肾炎(Thy-1 nephritis,Thy-1N)大鼠肾组织内转化生长因子-β1(transforming growth factor-β1,TGF-β1)生成的影响。方法:分别用慢病毒(lentivirus,LV)包装GCN5和SOX9发夹状小干扰RNA(shRNA),即制备LV-shGCN5和LV-shSOX9重组病毒。然后行大鼠肾动脉灌注术将LV-shGCN5和LV-shSOX9分别导入大鼠肾脏,再经尾静脉注射兔抗大鼠胸腺细胞抗血清(anti-thymocyte serum,ATS)复制Thy-1N模型。在注射ATS后3 h,取大鼠肾组织,用RTPCR和Western blot检查各组大鼠肾组织中GCN5和SOX9的mRNA及蛋白表达水平,以验证干扰效果及GCN5、SOX9对TGF-β1产生的影响。结果:利用肾动脉灌注术将LV-shGCN5或LV-shSOX9重组病毒导入大鼠肾组织后,不仅能有效沉默相应的靶基因,而且还能下调TGF-β1的表达。结论:沉默大鼠肾组织中GCN5或SOX9基因后能显著抑制Thy-1N大鼠肾内TGF-β1的生成。展开更多
文摘Background SRY-related HMG-box 17 （SOX17） encodes a member of the SOX （SRY-related HMG-box） family of transcription factors involved in the regulation of embryonic development and in the determination of the cell fate. Recently, it was considered as a tumor suppressor gene to inhibit canonical Wnt/β-catenin signaling pathway in several malignancies. However, the function of SOX17 in thyroid cancer was unknown. Therefore, we investigated the epigenetic changes and the function of SOX17 in thyroid cancer. Methods The methylation status of the promoter region of SOX17 was detected using methylation-specific PCR in 63 papillary thyroid carcinoma （PTC） tissue, 10 normal thyroid tissue, and two thyroid cancer cell lines. Semi-quantitative RT-PCR was used to assess mRNA expression of SOX17 before and after 5-aza-2＇-deoxycytidine treatment in thyroid cancer cell lines. Expression of SOX17 and β-catenin were detected by immunohistochemistry in PTC and adjacent tissue. Luciferase reporter assay, colony formation, transfection, and Western blotting were employed to analyze the effect of SOX17 on thyroid cancer cell proliferation and the function of SOX17 in the Wnt signal pathway. Results Loss of SOX17 expression was correlated to the promoter region hypermethylation in thyroid cancer cell lines. Re-expression of SOX17 was found in TPC-1 cell line after 5-aza-2＇-deoxycytidine treatment. In primary thyroid cancer, 60.3% （38/63） were methylated and 39.7% （25/63） unmethylated. But no methylation was found in noncancerous thyroid tissues. Methylation of SOX17 was associated reversely with β-catenin expression in the cytoplasm or nucleus significantly in the PTC （P 〈0.05）. Colony formation was inhibited by re-expression of SOX17 in TPC-1 cells. SOX17 suppressed the Wnt signaling pathway and the HMG domain was essential for this effect. Conclusions SOX17 was frequently methylated in human PTC. Loss of SOX17 expression was induced by promoter region hypermethylation. SOX17 inhibited thyroid cancer
