Quantitative analysis of thymosin beta-10 messenger RNA in thyroid carcinomas
Genes that are differentially expressed in benign and malignant tissues are important for the establishment of molecular-based diagnosis of carcinomas. Our recent study on the gene expression profile of thyroid carcinomas revealed an increased expression of thymosin beta-10 mRNA.
To confirm this, we measured the expression levels of thymosin beta-10 mRNA in 84 thyroid benign and malignant thyroid tissues, including five anaplastic carcinomas, by means of real-time quantitative reverse transcription-polymerase chain reaction.
We found an increased expression of thymosin beta-10 mRNA in thyroid carcinomas, especially in anaplastic carcinomas. Expression levels of thymosin beta-10 mRNA relative to thyroglobulin mRNA in anaplastic carcinomas were greatly increased compared with those in differentiated carcinomas.
These results suggest the usefulness of the quantitative measurement of thymosin beta-10 mRNA in molecular-based diagnosis of thyroid anaplastic carcinomas, but not of differentiated carcinomas.
Available from: PubMed Central
- "In cancer study, the role of Tbeta10 is controversial. High levels of Tbeta10 expression have been found in the metastatic tumor of thyroid
[9,10], and cutaneous malignancy
, while low levels of Tbeta10 expression have been associated with metastatic cervical carcinoma
. More recently, the expression features of Tbeta10 and Tbeta4 was reported by Theunissen et al.
, but Tbeta10’s relationship with clinicopathological characteristics and survival are still unknown. "
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Thymosin beta 10 (Tbeta10) overexpression has been reported in a variety of human cancers. However, the role of Tbeta10 in hepatocellular carcinoma (HCC) remains unclear. The aim of the present study was to analyze Tbeta10 expression in tumor and matched non-tumorous tissues, and to assess its prognostic significance for HCC after hepatectomy.
The level of Tbeta10 mRNA and protein in tumor and matched non-tumorous tissues was evaluated in 26 fresh HCC cases by reverse transcription-polymerase chain reaction (RT-PCR) and western blot. Additionally, Tbeta10 protein expression in 196 HCC was analyzed by immunohistochemistry (IHC) and correlated with clinicopathological characteristics and survival.
Results from RT-PCR and western blot analysis show that the levels of Tbeta10 mRNA and protein were significantly higher in tumor tissues of HCC, compared to that in matched non-tumorous tissues (P = 0.01 and P <0.001, respectively). IHC staining showed that high expression of Tbeta10 was detected in 58.2% (114/196) of HCC cases. High expression of Tbeta10 was significantly associated with advanced TNM stage (P <0.001). Survival analysis demonstrated that high Tbeta10 was related to shorter overall survival (OS) (P = 0.000) and disease-free survival (DFS) (P = 0.000). Multivariate analysis showed that high expression of Tbeta10 was an independent prognostic factor for both OS (P = 0.001, HR = 4.135, 95% CI: 2.603 to 6.569) and DFS (P = 0.001, HR = 2.021, 95% CI: 1.442 to 2.832). Subgroup analysis revealed that high expression of Tbeta10 predicts poorer survival for early and advanced stage.
Tbeta10 protein abnormal expression might contribute to the malignant progression of HCC. High expression of Tbeta10 predicts poor prognosis in patients with HCC after hepatectomy.
Available from: Koshi Hashimoto
- "The tymosin-beta 10 gene (Tmsb10) is related to cell growth through proliferation, and its expression is associated with brain development in rats and humans. In addition, previous reports indicated enhanced Tmsb10 expression in a variety of human tumors such as renal and thyroid medullary carcinomas and melanomas , . Although these two genes were found in the same cluster, cluster 5 to which the TSHβ gene belonged, the signals slightly increased in the absence of TRH, suggesting that these two genes were expressed in a TRH-independent manner. "
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ABSTRACT: Thyrotropin-releasing hormone (TRH) is a major stimulator of thyrotropin-stimulating hormone (TSH) synthesis in the anterior pituitary, though precisely how TRH stimulates the TSHβ gene remains unclear. Analysis of TRH-deficient mice differing in thyroid hormone status demonstrated that TRH was critical for the basal activity and responsiveness to thyroid hormone of the TSHβ gene. cDNA microarray and K-means cluster analyses with pituitaries from wild-type mice, TRH-deficient mice and TRH-deficient mice with thyroid hormone replacement revealed that the largest and most consistent decrease in expression in the absence of TRH and on supplementation with thyroid hormone was shown by the TSHβ gene, and the NR4A1 gene belonged to the same cluster as and showed a similar expression profile to the TSHβ gene. Immunohistochemical analysis demonstrated that NR4A1 was expressed not only in ACTH- and FSH- producing cells but also in thyrotrophs and the expression was remarkably reduced in TRH-deficient pituitary. Furthermore, experiments in vitro demonstrated that incubation with TRH in GH4C1 cells increased the endogenous NR4A1 mRNA level by approximately 50-fold within one hour, and this stimulation was inhibited by inhibitors for PKC and ERK1/2. Western blot analysis confirmed that TRH increased NR4A1 expression within 2 h. A series of deletions of the promoter demonstrated that the region between bp -138 and +37 of the TSHβ gene was responsible for the TRH-induced stimulation, and Chip analysis revealed that NR4A1 was recruited to this region. Conversely, knockdown of NR4A1 by siRNA led to a significant reduction in TRH-induced TSHβ promoter activity. Furthermore, TRH stimulated NR4A1 promoter activity through the TRH receptor. These findings demonstrated that 1) TRH is a highly specific regulator of the TSHβ gene, and 2) TRH mediated induction of the TSHβ gene, at least in part by sequential stimulation of the NR4A1-TSHβ genes through a PKC and ERK1/2 pathway.
Available from: cmu.edu.cn
- "A lot of reports in the literature documented higher expression of Tβ10 in tumor cells than in adjacent normal tissues . Moreover, Tβ10 expression is associated with the degree of tumor progression of thyroid and breast cancers   . It is therefore suggested that Tβ10 overexpression may be a general event of carcinogenesis  and can be used as a tumor progression or malignant potential marker . "
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ABSTRACT: The exact role of thymosin beta10 in lung cancer progression remains unclear. We investigated by immunohistochemistry the expression of thymosin beta10 protein in tumors and tumor-adjacent tissues from 69 patients with non-small cell lung cancer. The relationship of thymosin beta10 expression with vascular endothelial growth factor, vascular endothelial growth factor-C, microvessel density, and lymphatic vessel density was determined; clinicopathologic factors and surgical treatment outcome were also studied. The results showed that thymosin beta10 was mainly expressed in the cytoplasm of lung cancer cells, and the overexpression of thymosin beta10 was correlated with advanced clinical stage (P = .026), distant metastases (P = .016), lymph node metastases (P = .007), poor degree of differentiation (P = .03), and poor postoperative survival (P = .004). Furthermore, thymosin beta10 overexpression was associated with vascular endothelial growth factor (P = .004), vascular endothelial growth factor-C (P = .017), microvessel density (P = .000), and lymphatic vessel density (P = .002). The lowest survival rate was observed in the patients with high thymosin beta10, positive vascular endothelial growth factor, and high microvessel density (P = .007) or in the patients with high thymosin beta10, positive vascular endothelial growth factor-C, and high lymphatic vessel density (P = .005). These results suggest that thymosin beta10 might induce microvascular and lymphatic vessel formation by up-regulating vascular endothelial growth factor and vascular endothelial growth factor-C in lung cancer tissues, thus promoting the distant and lymph node metastases and being implicated in the progression of non-small cell lung cancer.
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