saRNA调控NIS基因介导131I对肝癌HepG2细胞体外抑制作用的实验研究

目的 探索通过小激活RNA(saRNA)调控钠碘转运体(NIS)基因特异性表达介导肝癌核素显像和治疗的可行性,为RNA激活(RNAa)技术介导核素基因治疗肿瘤的应用提供实验依据.方法 saRNA的设计合成:通过基因BLAST比对,设计与合成三条针对NIS基因的saRNA序列;细胞转染:以LipofectaminTM 2000为saRNA载体,将saRNA转染到肝癌HepG2细胞后72h,采用Western blotting分析NIS蛋白的表达水平,筛选出RNAa效率最高的saRNA,并进一步分析saRNA转染后不同时相NIS的表达水平,以及saRNA浓度-NIS表达水平的浓度-效应关系;体外核素摄取实验:体外培养条件下,评价转染肝癌HepG2细胞对125I的摄取;细胞生长增殖抑制实验:体外培养条件下,评价131 I对转染肝癌细胞的生长抑制率.结果 saRNA可上调NIS基因表达水平,其中saRNA482序列上调NIS表达水平最高;saRNA上调NIS的峰值出现在转染后72h,NIS维持高表达水平在10d以上;且NIS上调水平随saRNA浓度增高而增高.体外培养条件下,转染细胞与未转染细胞的摄碘水平差别明显,其中最高者摄碘较对照细胞高出64倍.体外培养条件下,相对未转染组肝癌细胞,131I对转染组HepG2细胞的生长抑制率为60.7％.结论 本研究设计合成的靶向NIS基因的saRNA可上调肝癌细胞NIS的表达水平,增强肝癌细胞摄取放射性碘的能力,研究还证实,通过RNAa调控NIS基因表达可介导131I治疗肝癌的潜力.     

AP-1和TGF-β1在低碘大鼠肾脏组织中的表达及意义

目的:研究低碘培养对大鼠甲状腺功能的影响及激活蛋白-1(activator protein-1, AP-1)和转化生长因子-β1(transforming growth factor-β1, TGF-β1)在肾组织中的表达差异, 探讨低碘地区肾脏损伤的可能发病机制.方法:给予Wistar大鼠低碘饲料, 通过饮用不同碘浓度的饮水来分组, 测定甲状腺功能状态.利用RT-PCR方法分析肾脏组织中AP-1亚单位c-Jun的激活变化情况.以免疫组化方法检测TGF-β1在肾组织中的表达差异.结果:重度低碘组(DLIG)与轻度低碘组(GLIG)、正常对照组(CL)比较FT3、 FT4均明显下降(P＜0.01).GLIG与CL相比FT3明显下降(P＜0.05), FT4稍有降低, 但差异无统计学意义(P＞0.05).低碘大鼠肾脏组织中c-Jun mRNA及TGF-β1表达均增加, 与低碘程度有依赖关系.结论:低碘摄入可引起甲状腺激素分泌紊乱, 甚至导致甲状腺功能减退, 与低碘程度有剂量依赖关系.低碘通过某种机制激活了AP-1, 进而活化了TGF-β1等细胞因子, 产生一系列的连锁反应, 引起肾脏损伤.     

促甲状腺激素受体及碘钠泵在人甲状腺癌中的表达及临床意义

目的 研究促甲状腺激素受体(TSHR)、碘钠泵(NIS)在甲状腺癌中的表达,探讨其在人甲状腺癌治疗中的作用. 方法采用免疫组织化学SABC法,检测TSHR、NIS在45例人正常甲状腺组织、45例乳头状甲状腺癌及21例未分化甲状腺癌中的表达. 结果 TSHR及NIS在人正常甲状腺组织的表达均高于其在乳头状甲状腺癌和未分化甲状腺癌中的表达.在人正常甲状腺组织,TSHR和NIS蛋白均定位于滤泡上皮细胞膜上;在乳头状甲状腺癌组织,TSHR蛋白定位于细胞膜和细胞质中,NIS蛋白仅在细胞质中有阳性表达;在未分化甲状腺癌,TSHR和NIS均定位于细胞质. 结论 TSHR、NIS的定位及表达水平与甲状腺癌的分化程度密切相关,可能成为预测甲状腺癌促甲状腺激素抑制治疗及131Ⅰ治疗是否有效的指标.     

过氧化物酶缺陷型激素合成障碍性甲状腺肿的核医学特征

用放射免疫法测定过氧化物酶缺陷型激素合成障碍性甲状腺肿病人血清TT3,TT4,FT3,FT4,TGAb,TMAb,用高敏感免疫放射法测定TSH,并进行碘过氨酸钾释放实验和~(99m)锝甲状腺静态显像,实验显示:该类病人血清甲状腺素水平降低,TSH水平升高,TGAb呈阴性反应;碘过氯酸钾释放试验呈阳性反应;核素显像显示甲状腺均匀性肿大,摄取~(99m)锝功能增加,结果表明:该类病人甲状腺细胞合成甲状腺素的关键酶—过氧化物酶活性低下,使进入甲状腺细胞的碘离子氧化为碘分子的过程受到抑制,该酶活性降低使甲状腺素水平降低,反馈性刺激垂体TSH分泌增加,在TSH刺激下,甲状腺增生肿大,摄取~(131)碘和~(99m)锝功能增加,SPECT静态显像甲状腺放射性分布浓聚,与桥本甲状腺炎鉴别诊断,测定血清甲状腺自身抗体TGAb,TMAb具有重要意义     

不同碘浓度对大鼠甲状腺摄碘功能的影响

观察不同碘摄入量对大鼠促甲状腺激素受体（TSHR）mRNA、钠碘转运体（NIS）mRNA以及血清过氧化物酶抗体（TPOAb）表达水平的影响。方法 SD大鼠30只,随机分成低碘组（LI）、适碘组（NI）和高碘组（HI）,每组10只。于实验第8、16周分批处死。实时荧光定量聚合酶链式反应法测定TSHR mRNA及NIS mRNA表达水平。酶联免疫分析法观察血清TPOAb浓度。结果 实验8周,低碘组和高碘组TSHR mRNA及NIS mRNA表达水平均低于适碘组,差异有统计学意义（P＜0.05）;且血清TPOAb浓度高于适碘组,但差异无统计学差异（P＞0.05）;实验16周,高碘组和低碘组的TSHR mRNA和NISmRNA表达水平均明显低于适碘组,差异有统计学意义（P＜0.05）;血清TPOAb浓度高于适碘组,差异有统计学意义（P＜0.05）。结论 包括碘过量和碘缺乏在内的长期碘营养障碍均可降低NIS及TSHR的正常表达,同时提高甲状腺自身抗体的浓度,影响甲状腺摄碘功能。     

钠碘转运体基因显像及治疗新进展

钠碘转运体（NIS）是一种位于甲状腺滤泡细胞膜上的糖蛋白，负责介导碘进入甲状腺滤泡细胞内。因为NIS的运碘特性，所以临床上有巨大的应用价值。目前，NIS基因可以作为报告基因进行显像，还可以通过NIS基因介导放射性核素治疗癌症。但是将这种方法应用于临床还面临很多问题，细胞中碘的有效半衰期较短就是其中之一。对此，已有的解决方法，一是，使用NIS介导更强的放射性核索；再是，进行甲状腺过氧化物酶基因（TPO）的共转染。     

探讨黄芪甲苷对桥本甲状腺炎大鼠甲状腺细胞凋亡及RhoA/ROCK2通路的影响

目的：探讨黄芪甲苷对桥本甲状腺炎（HT）大鼠甲状腺细胞凋亡及Ras同源基因家族成员A(RhoA)/Rho相关卷曲螺旋形成蛋白激酶2(ROCK2)通路的影响。方法：以皮下注射甲状腺球蛋白联合高碘饮水的方法诱导HT大鼠模型，随机分为模型组、黄芪甲苷（80 mg/kg）组、Rhosin(RhoA抑制剂，40 mg/kg)组、黄芪甲苷（80 mg/kg）+Rhosin(40 mg/kg)组（每组12只），另选出12只SD大鼠，正常饮水并皮下注射等剂量生理盐水作为对照组，经药物分组处理后，ELISA试剂盒测量血清抗甲状腺球蛋白抗体（TGAb）、抗甲状腺过氧化物酶抗体（TPOAb）水平及炎症因子IL-6、IL-17、IL-1β含量；通过苏木精-伊红（HE）染色检测各组大鼠甲状腺组织病理形态变化；通过原位末端标记法（TUNEL）染色检测各组大鼠甲状腺细胞凋亡率；通过Western blot实验检测各组大鼠甲状腺组织RhoA/ROCK2通路蛋白表达。结果：与对照组相比，模型组大鼠甲状腺滤泡结构异常，部分萎缩或消失，排列紊乱，周围存在炎症细胞浸润，甲状腺组织有明显病理损伤，血清TGAb、TPOAb、IL...     

雌激素对大鼠胸腺细胞凋亡及Bcl-2、Bax表达的影响

目的:探讨苯甲酸雌二醇对大鼠胸腺Bcl-2和Bax表达及细胞凋亡的影响及其机制.方法:雌性大鼠行卵巢切除术,给予苯甲酸雌二醇后,观察胸腺指数的变化,Hochest33342荧光染色及透射电镜标本观察胸腺细胞凋亡情况,免疫组织化学检测胸腺组织中Bcl-2和Bax的表达情况,原位杂交技术检测Bcl-2、Bax m RNA的表达情况.结果:双侧卵巢切除组大鼠胸腺指数较假手术组增加,双侧卵巢切除+雌激素组大鼠胸腺指数较双侧卵巢切除组减小;假手术组和双侧卵巢切除组大鼠胸腺组织中以正常胸腺细胞为主,偶见凋亡细胞或凋亡小体,双侧卵巢切除+雌激素组可见较多凋亡细胞和凋亡小体;双侧卵巢切除+雌激素组大鼠胸腺组织中Bcl-2表达较双侧卵巢切除组和假手术组增高明显降低,而Bax表达呈现相反趋势;Bcl-2 mRNA、Bax mRNA的表达与Bcl-2、Bax的表达呈一致性.结论:雌激素可以降低大鼠胸腺指数,抑制胸腺组织中Bcl-2的表达,促进Bax的表达,从而诱导大鼠胸腺细胞凋亡,促进雌性大鼠胸腺退化.     

模拟海拔5000米低氧环境下大鼠甲状腺轴与CRH家族的相关性研究

目的研究SD大鼠HPT轴激素及蛋白在低氧环境下的病理生理变化机制及与促肾上腺皮质激素释放激素(Corticotropin releasing hormone,CRH)家族相关蛋白及激素的相互作用。方法用低压低氧舱模拟海拔5 000 m高原低氧环境复制SD大鼠动物模型,采用ELISA法检测大鼠血清中HPT轴激素水平,包括游离三碘甲腺原氨酸(Free triido-thyronine,FT3)、游离四碘甲腺原氨酸(Free tetraiodo-thyronine,FT4)、总三碘甲腺原氨酸(Total triido-thyronine,TT3)、总四碘甲腺原氨酸(Total tetraiodo-thyronine,TT4)、反三碘甲腺原氨酸(3,5,3’-L-triiodo-thyronine,r T3)、促甲状腺激素(Thyrotropin stimulating hormone,TSH)、促甲状腺激素释放激素(Thyrotropin releasing hormone,TRH),以及CRH家族激素CRH、尿皮素2(Urocortin II,Ucn2)、Ucn3、皮质酮(Corticosterone,CORT)在血清中的水平,通过Western blot检测低氧诱导因子-1α(Hypoxia-inducible factor 1α,HIF-1α),HPT轴的TSHR、TRHR1及CRH家族受体CRHR1、CRHR2的表达。采用免疫荧光双染检测CRHR1、CRHR2与TSHR在甲状腺滤泡细胞的表达。通过Pearson相关分析探讨CRH家族CRH、Ucn2、Ucn3、CORT和HPT轴激素FT3、FT4、TT3、TT4、TSH、TRH、r T3相关性。结果低氧组大鼠TRH、TT3、TT4、FT3、FT4和TSH血清水平均下降(P0.05),r T3、CRH、Ucn2、Ucn3和CORT血清浓度上升(P0.05)。相关性统计表明低氧各组大鼠血清CRH与TRH激素水平负相关(r=-0.80),Ucn2与FT3、TT3分别呈负相关(r=-0.796,-0.798)。免疫荧光双标显示CRHR1与TSHR、CRHR2与TSHR在甲状腺滤泡细胞存在共表达。结论结果表明模拟5000米海拔低氧环境使大鼠HPT轴功能受到抑制,可能与CRH家族基因激活有关,这对进一步研究HPT轴与CRH家族相互作用机制提供一定的线索。     

缺碘和氟中毒对大鼠甲状腺的协同作用

实验用Wistar大鼠212只,按饮食中碘和氟含量不同随机分为五组,实验期为7个月。结果显示:摄碘正常的大鼠长期饮用30ppm氟水后引起甲状腺功能和形态的严重损害,而饮用10ppm氟水的大鼠仅见甲状腺滤泡上皮超微结构的轻度异常变化;单纯性缺碘大鼠甲状腺肿大并伴有代偿性功能变化,缺碘并饮用10ppm氟水的大鼠在其甲状腺肿大的同时伴有明显的形态结构损伤及甲状腺代偿功能抑制,甚至功能低下。     

Histiocytosis X of the thyroid masquerading as thyroid carcinoma

The case of a 28-year-old woman with histiocytosis X confined to the thyroid is described. A partial thyroidectomy specimen from this patient was at first interpreted as showing poorly differentiated thyroid carcinoma. Subsequent investigations, including electron microscopy, revealed the true nature of the lesion. Even on retrospective examination, the two conditions can simulate each other very closely and may be easily confused.     

Histoplasmosis of the thyroid

Fungal infection of the thyroid is rare. Most reported cases have involved Aspergillus, Coccidioides, and Candida species in the setting of disseminated disease. Infection of the thyroid with Histoplasma capsulatum is rarely reported as part of disseminated disease, even in geographic areas where histoplasmosis is endemic. We report a 52-year-old woman with a previous Hashimoto's disease and non-Hodgkin's lymphoma in which a diffuse enlarged thyroid gland with a large nodule was the only apparent locus of histoplasmosis. Fine-needle aspiration of the thyroid was an important diagnostic tool in establishing the diagnosis of histoplasmosis of the thyroid. The patient was initially treated with itraconazole (400 mg/day) for the fungal infection and six cycles of chemotherapy for the lymphoma. At a 6-month follow-up examination, the patient was doing well on suppressive therapy of itraconazole (200 mg/day), with no symptoms and with regression of the thyroid nodule and cervical adenopathy.     

Plasmacytoma of the thyroid

Three cases of plasmacytoma of the thyroid are described and their clinical and histological features recorded. Two were considered to be true extramedullary plasmacytomas, the third the initial manifestation of a disseminated myelomatous process. Plasmacytomas of the thyroid are shown to have many features in common with malignant lymphomas in this site, including an association with Hashimoto thyroiditis in more than half the reported cases. No certain method of assessing the prognosis in any individual case has yet been described.     

Microcarcinoma of the thyroid

Thyroid microcarcinoma, defined as a thyroid tumor measuring 1 cm or less, is an extremely indolent tumor. Papillary microcarcinoma, the most common subtype, is often identified incidentally in a thyroid removed for benign clinical nodules or diffuse processes (eg, thyroiditis). In this clinical situation, over 99% are cured by simple lobectomy. In the less common scenario, the microcarcinoma is the primary lesion to a lymph node metastasis presenting clinically as a neck mass; in this situation, the tumor should be treated as a clinical cancer. Other rare microcarcinomas can occur and, of these, the most recently described is micromedullary carcinoma. In the familial setting, these lesions are identified in prophylactic thyroidectomies and are not unexpected findings. However, when found as sporadic tumors, their implications are still unknown. The histologic features, pathologic mimics, and molecular facets of these microscopic neoplasms are discussed in this review.     

Pseudolymphoma of the thyroid

An unusual case of pseudolymphoma of the thyroid is reported. The tumor was histologically characterized by good demarcation, mature lymphocytes with prominent follicle formation and germinal centers, and mature plasma cells. Immunohistochemical staining revealed a similar distribution of T- and B-cells to reactive lymph nodes and a polyclonal nature of the plasma cell infiltrate. These findings are closely related to the entity, pseudolymphoma in other organs. Differential diagnosis from follicular lymphoma or ectopic thymic tissue is discussed.     

Solid cell nests of the thyroid in medullary thyroid carcinoma

Solid cell nests of the thyroid gland were studied in 44 patients with medullary thyroid carcinoma. In 10 (22.7%) patients, solid cell nests were revealed in the vicinity of tumour foci (five cases) or in the contralateral thyroid lobe and isthmus (four cases); in one case the location was indeterminate. In all seven cases in which immunohistochemical studies were carried out, solid cell nests showed negative staining for thyroglobulin, calcitonin and chromogranin A, findings which were distinct from those in medullary thyroid carcinoma. It is therefore suggested that solid cell nests of the thyroid are not precursors of this tumour.