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THBD

The expression of thrombomodulin (TM), a calcium-dependent adhesion molecule, is frequently downregulated in various cancer types. However, the mechanism responsible for the low expression level of TM in tumorigenesis is unknown. Here, an inverse expression of TM and Snail was detected in different cancer cell lines. We further confirmed this inverse relation using the epithelial-mesenchymal transition cell model in HaCaT and A431 cells. We demonstrated that Snail suppressed TM expression by binding to E-box (CACCTG) in TM promoter. Moreover, TM knockdown by short hairpin RNA disrupted E-cadherin-mediated cell junctions and contributed to tumorigenesis. In the calcium switch assay, E-cadherin lost the ability to associate with beta-catenin and accumulated in cytoplasm in TM knockdown cells. Meanwhile, wound healing and invasive assays showed that TM knockdown promoted cell motility. A subcutaneous injection of TM knockdown transfectants into immunocompromised mice induced squamous cell carcinoma-like tumors. Besides, forced expression of murine TM in TM knockdown cells made the cells reassume epithelium-like morphology and increased calcium-dependent association of E-cadherin and beta-catenin. In conclusion, TM, a novel downstream target of Snail in epithelial-mesenchymal transition, is required for maintaining epithelial morphology and functions as a tumor suppressor.

Thrombomodulin (TM) has been shown to regulate many physiological and pathological processes, including inflammation, thrombosis, and tumor progression. TM is also a natural anticoagulant that maintains circulatory homeostasis in endothelial cells. However, little is known regarding the role of TM in the progression and metastasis of cervical cancer. TM-specific RNA interference and a cDNA expression vector were used to manipulate TM expression in cervical cancer cells. Cell growth and cell migration were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, transwell migration assays, and a biosensor system. TM silencing did not affect the growth rate of the cells. However, cell migration was dramatically enhanced after silencing of TM in HeLa cells. The overexpression of TM in cervical cancer cells only slightly influenced their proliferative capacity. After overexpression of TM in HeLa cells, their migratory capability was suppressed. Furthermore, we found that the decreased expression of E-cadherin and increase of zeb-1 and snail expression in TM-silenced cells which may be correlated with the results of knocking-down TM increases the migratory ability in this study. Our results demonstrate that TM may slightly regulate the growth but played the important role in the migratory ability of cervical cancer cells, suggesting that TM could potentially serve as a novel prognostic and therapeutic target in cervical cancer.

Thrombomodulin (TM) is an endothelial cell membrane protein and plays critical roles in anti-thrombosis, anti-inflammation, vascular endothelial protection, and is traditionally regarded as a "vascular protection god". In recent years, although TM has been reported to be down-regulated in a variety of malignant tumors including lung cancer, the role and mechanism of TM in lung cancer are enigmatic. In this study, we found that induction of TM overexpression by cholesterol-reducing drug atorvastatin significantly diminished the tumorigenic capability of the lung cancer cells. Moreover, we demonstrated that TM overexpression caused G0/G1 phase arrest and markedly reduced the colony forming capability of the cells. Furthermore, overexpression of TM inhibited cell migration and invasion. Consistently, depletion of TM promoted cell growth, reduced the cell population at the G0/G1 phase, and enhanced cell migratory ability. Mechanistic study revealed that TM up-regulated E-cadherin but down-regulated N-cadherin expression, resulting in reversal of epithelial-mesenchymal transition (EMT) in the lung cancer cells. Moreover, silencing TM expression led to decreased E-cadherin and increased N-cadherin. Taken together, our study suggests that TM functions as a tumor suppressive protein, providing a conceptual framework for inducing TM overexpression as a sensible strategy and approach for novel anti-lung cancer drug discovery.CI - Copyright (c) 2016 Elsevier Inc. All rights reserved.

BACKGROUND: Treatment resistance and metastasis are the major causes of death among patients with colorectal cancer (CRC). Approximately 20% of surgically treated patients ultimately develop metastases during the follow-up period. Currently, the TNM system is the only available prognostic test. Therefore, the identification of new markers for CRC remains important. Thrombomodulin (TM), a glycoprotein, is involved in angiogenesis and has been linked to many malignant diseases. However, the function of TM in CRC remains unclear. METHODS: A total of 170 patients with CRC participated in this study. TM expression was analyzed via immunohistochemistry. Univariate (Kaplan-Meier) analysis was used to analyze patient outcomes, including overall survival (OS) and disease-free survival (DFS). TM expression was manipulated using shRNA or an overexpression system. Transwell migration assays, wound healing migration assays, and the xCELLigence biosensor system were used to detect cell proliferative and migratory capacities. RESULTS: TM expression in the tumor tissues significantly and positively correlated with the DFS and OS of non-metastatic patients with CRC (ps = 0.036 and 0.0218, respectively). Suppression of TM expression increased the proliferation and migration of DLD-1 cells. TM overexpression reduced the cells' proliferative and migratory capacities. Cyclooxygenase (COX)-2 expression was up-regulated following TM silencing. Furthermore, the association between the migration of colon cancer cells and the levels of TM and epithelial-to-mesenchymal transition (EMT) markers (fibronectin, vimentin and ezrin) was confirmed in HT29 and DLD-1 cells. CONCLUSIONS: Our study demonstrates that patients with non-metastatic CRC display low TM expression in their tumors and exhibit reduced DFS and OS. The enhanced expression of mesenchymal markers and COX-2 may be involved in the mechanisms that underlie recurrence in patients with cancer displaying low TM expression.