Amplification-independent overexpression of thymosin beta-10 mRNA in human renal cell carcinoma

TMSB10 acts as a biomarker and promotes progression of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is one of the most common urological malignancies. Identifying novel biomarkers and investigating the underlying mechanism of ccRCC development will be crucial to the management and treatment of ccRCC in patients. Thymosin b10 (TMSB10), a member of the thymosin family, is involved in various physiological processes, including tissue regeneration and inflammatory regulation. Moreover, it has been found to be upregulated in many types of carcinoma. However, its roles in ccRCC remain to be elucidated. The present study aimed to explore the expression of TMSB10 in ccRCC through mining The Cancer Genome Atlas (TCGA) and Oncomine databases, and to investigate the association between TMSB10 expression and clinicopathological factors. Furthermore, immunohistochemistry assays and western blotting were conducted to verify TMSB10 expression levels in human ccRCC tissues and cell lines. Functional analyses were also performed to identify the roles of TMSB10 in vitro. The results revealed that TMSB10 was significantly upregulated in RCC tissues and cell lines. The expression of TMSB10 was closely associated with various clinicopathological parameters. In addition, high expression of TMSB10 predicted poor clinical outcome. The receiver operating characteristic curve revealed that TMSB10 could sufficiently distinguish the tumor from normal kidney (area under the curve = 0.9543, P<0.0001). Furthermore, knockdown of TMSB10 impaired the proliferation of ccRCC cells, and attenuated cell and invasion in vitro. In addition, TMSB10 knockdown downregulated reduced the phosphorylation of PI3K and the expression of vascular endothelial growth factor. In conclusion, the present study demonstrated that high expression of TMSB10 could serve as a useful diagnostic and prognostic biomarker and a potential therapeutic target for ccRCC.

Thymosin β 10 is overexpressed and associated with unfavorable prognosis in hepatocellular carcinoma

Thymosin β 10 (TMSB10) has been demonstrated to be overexpressed and function as an oncogene in most types of human cancer including hepatocellular carcinoma (HCC). In our study, we present more evidence about the clinical significance and biological function of TMSB10 in HCC. First, we observed levels of TMSB10 expression were obviously increased in HCC tissues compared with normal liver tissues at The Cancer Genome Atlas (TCGA) datasets. Furthermore, we confirmed that TMSB10 mRNA and protein levels were also increased in HCC tissue samples compared with normal adjacent normal liver tissue samples. In addition, we found high TMSB10 expression was remarkably associated with the advanced tumor stage, large tumor size, distant metastasis, and poor prognosis, and acted as an independent factor for predicting poor overall survival in HCC patients. Loss-of-function studies suggested silencing of TMSB10 expression dramatically reduced cell proliferation, migration, and invasion in HCC. In conclusion, TMSB10 may hold promise as a tumor biomarker for predicting prognosis and a potential target for developing a novel therapeutic strategy.

High expression of thymosin beta 10 predicts poor prognosis for hepatocellular carcinoma after hepatectomy

Background

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.

Methods

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

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.

Conclusions

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.

Thymosin β10 expression driven by the human TERT promoter induces ovarian cancer-specific apoptosis through ROS production

Thymosin β(10) (Tβ(10)) regulates actin dynamics as a cytoplasm G-actin sequestering protein. Previously, we have shown that Tβ(10) diminishes tumor growth, angiogenesis, and proliferation by disrupting actin and by inhibiting Ras. However, little is known about its mechanism of action and biological function. In the present study, we establish a new gene therapy model using a genetically modified adenovirus, referred to as Ad.TERT.Tβ(10), that can overexpress the Tβ(10) gene in cancer cells. This was accomplished by replacing the native Tβ(10) gene promoter with the human TERT promoter in Ad.TERT.Tβ(10). We investigated the cancer suppression activity of Tβ(10) and found that Ad.TERT.Tβ(10) strikingly induced cancer-specific expression of Tβ(10) as well as apoptosis in a co-culture model of human primary ovarian cancer cells and normal fibroblasts. Additionally, Ad.TERT.Tβ(10) decreased mitochondrial membrane potential and increased reactive oxygen species (ROS) production. These effects were amplified by co-treatment with anticancer drugs, such as paclitaxel and cisplatin. These findings indicate that the rise in ROS production due to actin disruption by Tβ(10) overexpression increases apoptosis of human ovarian cancer cells. Indeed, the cancer-specific overexpression of Tβ(10) by Ad.TERT.Tβ(10) could be a valuable anti-cancer therapeutic for the treatment of ovarian cancer without toxicity to normal cells.

Thymosin beta-10 is aberrantly expressed in pancreatic cancer and induces JNK activation

Thymosin beta-10 (T beta 10) has been shown to be associated with several cancers; however, its role in pancreatic cancer is not understood. The expression of T beta 10 was determined by immunohistochemistry and real-time polymerase chain reaction. The phosphorylation of JNK and the cytokine secretion was determined by using the Bio-Plex phosphoprotein and cytokines assays. Pancreatic cancer tissues and cells expressed higher amounts of T beta 10 than normal surrounding tissues and human pancreatic duct epithelial cells. Exogenous T beta 10 caused the phosphorylation of JNK and increased the secretion of cytokines interleukin (IL)-7 and IL-8 in BxPC-3 cells. T beta 10 might be a promising marker and a novel therapeutic target for pancreatic cancer.

Overexpression of the thymosin beta-10 gene in human ovarian cancer cells disrupts F-actin stress fiber and leads to apoptosis

To understand the molecular changes during ovarian cancer development, we profiled differentially expressed genes in five paired normal and cancerous ovarian tissues. Among the genes that showed differential expression, thymosin beta-10 expression was decreased in four of five cancer tissues. The decreased level of expression was confirmed by Northern. To investigate the gene's functional role in ovarian cancers, we constructed an adenovirus vector expressing thymosin beta-10 and used it to infect ovarian cancer cell lines PA-I and SKOV3. The infected cells showed disrupted F-actin stress fibers, markedly decreased cell growth, and a high rate of apoptosis. Thus, because loss of thymosin beta-10 expression may contribute to the development of a subset of ovarian cancers, restoration of thymosin beta-10 expression may be a new strategy for ovarian cancer treatment.

Preliminary findings on the expression of thymosin beta-10 in human breast cancer

Paraffin sections from 30 human breast tissue specimens were stained with a specific antibody for thymosin beta-10, ATB10(38-43). The results showed that thymosin beta-10 was detected mainly in the malignant tissue, particularly in the cancerous cells, whereas the normal cell population around the lesions showed very weak staining. Also, the intensity of staining in the cancerous cells was proportionally increased with the increasing grade of the lesions.

Development of specific anti-thymosin beta 10 antipeptide antibodies for application in immunochemical techniques

We present theoretical and experimental data necessary for raising specific antibodies for thymosin beta 10, a 43-amino acid residues peptide occurring in human tissues. We postulate that thymosin beta 10 contains three major antigenic determinants (residues 2-8, 17-25, and 35-41). For antibody development, we synthesized the N-terminal fragment thymosin beta 10(1-16) as well as the C-terminal fragments thymosin beta 10(31-43) and thymosin beta 10(38-43), due to their putative antigenic properties and minimal structural similarity with the homologous peptide thymosin beta 4, which also occurs in humans. The putative antigenic determinant 17-25 is present in all beta-thymosins and was therefore not synthesized. All antisera raised against the above peptide fragments or the intact molecule of thymosin beta 10 were found capable of recognizing and binding synthetic or natural thymosin beta 10 with high specificity, showing minimal cross-reactivity with thymosin beta 4 isolated from bovine tissues or synthetic thymosin alpha 1. Due to its easy preparation and the highly specific affinity of the antibody raised against it for the intact peptide, the fragment thymosin beta 10(38-43) may be considered the antigen of choice for developing anti-thymosin beta 10 antibodies, which can eventually be applied to immunochemical studies.