目的 通过检测低氧诱导因子-2α(HIF-2α)、CITED2和PTPRZ1在甲状腺乳头状癌（PTC）中的表达；分析三者在PTC发生、发展中的作用及临床意义，探讨HIF-2α在PTC中的作用机制。 方法 采用免疫组织化学法、Western blotting及Real-time PCR法检测HIF-2α、CITED2和PTPRZ1在50例甲状腺乳头状癌中的表达，并分析三者的变化与临床病理特征的关系。 结果 PTC组织中HIF-2α、CITED2和PTPRZ1的mRNA和蛋白表达水平明显高于三者在甲状腺腺瘤组织和瘤旁正常组织中的表达（P＜0.05），且蛋白表达量与PTC淋巴结转移、病理分期及肿瘤大小有关（P＜0.05），而与PTC患者年龄、性别无关（P＞0.05）。 结论 在PTC中HIF-2α、CITED2和PTPRZ1蛋白的高表达与肿瘤的淋巴结转移、大小和临床病理分期呈正相关，HIF-2α可能通过CITED2和PTPRZ1的高表达促进PTC的发生、发展、侵袭及转移，三者在PTC的发生、发展和转移的过程中起重要的作用。

Objective To analyze the role and clinical significance of hypoxia inducible factor 2α(HIF-2α),CITED2 and PTPRZ1 during the development of papillary thyroid carcinoma (PTC) by detecting the expressions of HIF-2α,CITED2 and PTPRZ1 in the PTC tissues. Methods The expressions of HIF-2α,CITED2 and PTPRZ1 proteins in 50 cases of PTC were detected by Western blotting and immunohistochemical SP method, and the relationships with the clinical pathology characteristics were analyzed.The transcriptional level changes of HIF-2αmRNA,CITED2mRNA and PTPRZ1mRNA were tested by real-time reverse transcription polymerase chain reaction. Results The positive expression rate of HIF-2α CITED2 and PTPRZ1 in PTC tissues were obviously higher than that in thyrvid adenoma(TA) group and normal thyroid(N) group（P＜0.01）and expressions between N and TA were no significant difference （P＞0.05）. The expressions of HIF-2α, CITED2 and PTPRZ1 were unrelated to the age, sex and size of the tumor (P>0.05) of PTC patients, but associated with the lymph node metastasis and pathological stage (P<0.05). The transcriptional expression levels of the HIF-2α mRNA, CITED2 mRNA and PTPRZ1 mRNA in PTC tissues were significantly higher than in TA and normal tissues adjacent to the tumors with statistical significance(P<0.05), but there was no statistical difference between in TA and normal tissues adjacent to the tumors (P>0.05). Conclusion The higher expressions of HIF-2α, CITED2 and PTPRZ1 in PTC have a positive correlation with the lymph node metastasis, size and clinicopathologic stage. HIF-2α may promote the occurrence, development, invasion and metastasis of PTC by the higher expression of CITED2 and PTPRZ1.All of them play an important role in the process of PTC, include the occurrence, development, invasion and metastasis.