Shi Y, Zou M, Farid N R
Department of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.
Clin Endocrinol (Oxf). 1993 Sep;39(3):269-74. doi: 10.1111/j.1365-2265.1993.tb02365.x.
The clinical course of thyroid carcinoma is very variable. It is well known that thyroid carcinomas of similar histology can behave differently in terms of local invasion and distant metastases: there is no reliable way to predict the disease course with confidence. In the present study we compared the TSH receptor and c-myc mRNA levels in different stages of thyroid carcinomas to identify whether they are useful markers for thyroid tumour biological behaviour and prognosis.
Thyroid tumour specimens were used as the source of RNA. The TSH receptor and c-myc mRNA levels were detected by Northern blot analysis and quantitated by laser densitometry.
Thyroid tissues were obtained from five patients with multinodular goitres, 22 with differentiated and three with anaplastic carcinomas.
Total cellular RNA was extracted from thyroid tissue specimens and blotted onto nylon membranes. Northern blot analysis was used to detect TSH receptor and c-myc mRNA. The mRNA levels were then quantitated by laser densitometry and compared with each disease stage.
TSH receptor mRNA levels were significantly lower in carcinomas as compared to benign tumours. With advancing disease stage, the neoplastic tissues generally showed a progressive decline in TSH receptor mRNA levels. Interestingly, in two specimens from patients with distant metastases, TSH receptor mRNA levels were not significantly reduced and were comparable to those in benign tumours. Both patients are still alive, one of them 18 years after operation, indicating that tumour histology is dissociated from its biological behaviour. c-myc mRNA levels were increased but not significantly so in stage 1-3 carcinomas. However, in stage 4 carcinomas c-myc expression was significantly increased. Thus c-myc overexpression is associated with poor prognosis. Although there is a negative correlation between TSH receptor and c-myc mRNA levels, the correlation was not significant.
These results indicate that decreased TSH receptor and increased c-myc gene expression levels are associated with thyroid cell de-differentiation. They are useful markers for thyroid tumour de-differentiation and disease prognosis.
甲状腺癌的临床病程变化很大。众所周知，组织学相似的甲状腺癌在局部侵袭和远处转移方面表现各异：目前尚无可靠方法能准确预测疾病进程。在本研究中，我们比较了甲状腺癌不同阶段促甲状腺激素（TSH）受体和c-myc信使核糖核酸（mRNA）水平，以确定它们是否为甲状腺肿瘤生物学行为和预后的有用标志物。
以甲状腺肿瘤标本作为核糖核酸来源。通过Northern印迹分析检测TSH受体和c-myc mRNA水平，并通过激光密度测定法定量。
甲状腺组织取自5例多结节性甲状腺肿患者、22例分化型甲状腺癌患者和3例未分化癌患者。
从甲状腺组织标本中提取总细胞核糖核酸，并印迹到尼龙膜上。用Northern印迹分析检测TSH受体和c-myc mRNA。然后通过激光密度测定法定量mRNA水平，并与各疾病阶段进行比较。
与良性肿瘤相比，癌组织中TSH受体mRNA水平显著降低。随着疾病阶段进展，肿瘤组织中TSH受体mRNA水平通常呈逐渐下降趋势。有趣的是，在2例有远处转移患者的标本中，TSH受体mRNA水平未显著降低，与良性肿瘤中的水平相当。这2例患者均存活，其中1例术后存活18年，表明肿瘤组织学与其生物学行为不一致。在1-3期癌中，c-myc mRNA水平升高，但无显著差异。然而，在4期癌中，c-myc表达显著增加。因此，c-myc过表达与预后不良相关。虽然TSH受体和c-myc mRNA水平之间存在负相关，但相关性不显著。
这些结果表明，TSH受体降低和c-myc基因表达水平升高与甲状腺细胞去分化有关。它们是甲状腺肿瘤去分化和疾病预后的有用标志物。
