9168

TMSB10

thymosin beta 10;TMSB10;thymosin beta 10

migration-inducing gene 12|migration-inducing protein 12|thymosin beta-10

2p11.2

protein-coding

BACKGROUND: Thymosin beta10 (Tbeta10) expression is associated with malignant phenotypes in many cancers. However, the role and mechanisms of Tbeta10 in liver fluke-associated cholangiocarcinoma (CCA) are not fully understood. In this study, we investigated the expression of Tbeta10 in CCA tumor tissues and cell lines as well as molecular mechanisms of Tbeta10 in tumor metastasis of CCA cell lines. METHODS: Tbeta10 expression was determined by real time RT-PCR or immunocytochemistry. Tbeta10 silence or overexpression in CCA cells was achieved using gene delivery techniques. Cell migration was assessed using modified Boyden chamber and wound healing assay. The effect of silencing Tbeta10 on CCA tumor metastasis was determined in nude mice. Phosphorylation of ERK1/2 and the expression of EGR1, Snail and matrix metalloproteinases (MMPs) were studied. RESULTS: Ten pairs of CCA tissues (primary and metastatic tumors) and 5 CCA cell lines were studied. With real time RT-PCR and immunostaining analysis, Tbeta10 was highly expressed in primary tumors of CCA; while it was relatively low in the metastatic tumors. Five CCA cell lines showed differential expression levels of Tbeta10. Silence of Tbeta10 significantly increased cell migration, invasion and wound healing of CCA cells in vitro; reversely, overexpression of Tbeta10 reduced cell migration compared with control cells (P<0.05). In addition, silence of Tbeta10 in CCA cells increased liver metastasis in a nude mouse model of CCA implantation into the spleen. Furthermore, silence of Tbeta10 activated ERK1/2 and increased the expression of Snail and MMPs in CCA cell lines. Ras-GTPase inhibitor, FPT inhibitor III, effectively blocked Tbeta10 silence-associated ERK1/2 activation, Snail expression and cell migration. CONCLUSIONS: Low expression of Tbeta10 is associated with metastatic phenotype of CCA in vitro and in vivo, which may be mediated by the activation of Ras, ERK1/2 and upregulation of Snail and MMPs. This study suggests a new molecular pathway of CCA pathogenesis and a novel strategy to treat or prevent CCA metastasis.

Papillary thyroid carcinoma (PTC) is the most common well-differentiated thyroid cancer. Although the great majority of the cases exhibit an indolent clinical course, some of them develop local invasion with distant metastasis, and a few cases transform into undifferentiated/anaplastic thyroid carcinoma with a rapidly lethal course. To identify gene copy number alterations predictive of metastatic potential or aggressive transformation, array-based comparative genomic hybridization (CGH-array) was performed in 43 PTC cases. Formalin-fixed and paraffin-embedded samples from primary tumours of 16 cases without metastasis, 14 cases with only regional lymph node metastasis, and 13 cases with distant metastasis, recurrence or extrathyroid extension were analysed. The CGH-array and confirmatory quantitative real-time PCR results identified the deletion of the EIF4EBP3 and TRAK2 gene loci, while amplification of thymosin beta 10 (TB10) and Tre-2 oncogene regions were observed as general markers for PTC. Although there have been several studies implicating TB10 as a specific marker based on gene expression data, our study is the first to report on genomic amplification. Although no significant difference could be detected between the good and bad prognosis cases in the A-kinase anchor protein 13 (AKAP13) gene region, it was discriminative markers for metastasis. Amplification in the AKAP13 region was demonstrated in 42.9% and 15.4% of the cases with local or with distant metastasis, respectively, while no amplification was detected in non-metastatic cases. AKAP13 and TB10 regions may represent potential new genomic markers for PTC and cancer progression.