The Role Of Thyroid Hormone And Its Receptor Trβ Gene Mutation In Pathogenesis And Prognosis Of Thyroid Cancer

Objectives:(1) To assess a possible correlation between thyroid hormone and thyroid cancer. (2) To characterize a possible correlation between the TR(3 gene exon 7 mutation and thyroid cancer.Mothods:(1)The blood serum of thyroid hormone was assayed by electrochemiluminescence in 36 thyroid cancer,42 benign lesion and 30 normal subjects. (2) The tissue of thyroid hormone was assayed by immunohistochemical staining in 48 thyroid cancer,45 benign lesion and 16 normal subjects. (3) Polymerase chain reaction-single strand conformation polymorphism analysis (PCR-SSCP) method and DNA sequencing technology, based on conformational change of TRβgene exons 7 mutation detection in 82 cases of thyroid cancer. Enumeration data mainly useχ2 analysis and Logistic recurrence analysis, measurement data mainly use one-factor analysis of variance and multiple linear regression. Size of test isα=0.05.Results:(1)①The level of FT3 and FT4 in thyroid cancer are both lower than in that benign lesion and control group (P<0.001).②The level of T3 and T4 are nonsense between three groups (P>0.05).②The FT3 level is inverse proportion with tumor pathology staging and lymphoid node metabasis. (2)①FT3 expression is sense in thyroid cancer, benign lesion and normal subjects (P<0.05).②the positive rate of FT3 in thyroid cancer is 70.8%,which is lower than in that benign lesion 91.1% and control group 100%,. difference is sense (P<0.0125). (3) 82 cases of thyroid cancer in three cases of detected mutations:exon 7 at codon 1028 by a C→A missense mutation of the mutant amino acids so that mutation of aminothiopropionic acid to aminopropionic acid; exon 7 at codon 980 of the C→G missense mutation, mutant amino acids so that phenylalanine mutation to aminoacetic acid;exon7 at codon 1038 of the A→T missense mutation, mutant amino acids so that aminopropionic acid mutation to threonine.Conclusions:(1) The difference of the T3 level is sense,means that low T3 level may play a certain role in thyroid cancer. (2) 40%Thyroid cancer with low T3 level following low T4 level,which means low T4 level may be a factor to induce low T3 level. (3) the T3 level is inverse proportion with tumor pathology staging and lymphoid node metabasis,to test thyroid hormone can be as one of predictors to evaluate thyroid cancer prognosis. (4) TRβgene exon7 mutation of thyroid cancer is not frequent events and means which is can not afford a major role in thyroid cancer.