各型甲状腺肿瘤组织中生长抑素受体的表达

Expression of somatostatin receptor in human thyroid carcinoma

目的用原位杂交方法观察生长抑素受体在甲状腺肿瘤组织及癌旁组织中的表达。方法根据生长抑素受体(SSTR)亚型的基因结构设计两种cDNA探针:针对各型生长抑素受体的寡核苷酸探针以及特异性针对二型生长抑素受体(SSTR2)的寡核苷酸探针序列,并分别与各型甲状腺肿瘤组织及癌旁组织行原位杂交,采用Mias图像分析仪进行灰度分析,mRNA丰度以信号强度x-±s表示,进行t检验。结果甲状腺髓样癌组织中SSTR的表达明显高于癌周组织(P<0.05),SSTR2仅在癌组织中有表达。SSTR在甲状腺乳突状癌组织中的表达明显高于癌周组织(P<0.05),SSTR2在癌组织及癌周组织内均未见有表达。滤泡性腺癌组织SSTR的表达明显高于癌周组织(P<0.05),癌组织及癌周组织均未见有SSTR2表达。嗜酸性细胞癌组织SSTR的表达明显高于癌周组织(P<0.05),SSTR2仅在癌组织中有表达。结论SSTR2仅在MTC及HCC的肿瘤组织中有表达;各型甲状腺肿瘤组织均表达除SSTR2之外的其他几型SSTR中的一种或数种,且肿瘤组织中的表达强度明显高于邻近正常组织。某些靶向生长抑素受体(尤其是特异性靶向SSTR2)的化合物(配体),可能成为甲状腺肿瘤尤其是甲状腺髓样癌和嗜酸性细胞癌的特异性显像剂和靶向治疗载体。

Objective To observe the expression of subtype 2 of somatostatin receptor （SSTR2） and other subtypes of somatostatin receptors （SSTRs） in thyroid tumor tissues and the adjacent tissues. Methods Oligonucleotide probes against for all types of SSTR and oligonucleotide probes especially against for SSTR2 were designed according to the gene structure of SSTR. The hybridization in situ was performed among both riboprobes and frozen slices of various types of thyroid tumors. The positive signal strength of mRNA expression, intensity of mRNA and signal strength were obtained based on the gray analysis of Mias image analyzer. Results The positive signals of SSTR2 were found in the cytoplasms of medullary thyroid carcinoma （MTC） cells and htirthle cell carcinoma （HCC） cells, but not in the cytoplasms, nor in the adjacent tissues of papillary thyroid carcinoma （PTC） and follicular thyroid carcinoma （FTC）. The positive signals of SSTRs were found in both cytoplasms and the adjacent tissues of MTC, FTC, PTC and HCC, and the signals in tumor tissue were significantly stronger than those in the adjacent tissues （P〈0.05）. Conclusion SSTR2 is only expressed in the tumor tissues of MTC and HCC. One or more types of SSTRs are expressed in all types of thyroid tumor tissues and the adjacent tissues, although the expression in the former is stronger than that in the latter.