TMPRSS4 Expression Research Articles

TMPRSS4 promotes cancer stem cell traits by regulating CLDN1 in hepatocellular carcinoma

Encouraging advances in the treatment of hepatocellular carcinoma(HCC) have been achieved; however, a considerable part of patients still relapse or metastasize after therapy, and the underlying mechanisms have not been clarified yet. Here, we found that CLDN1 was markedly up-regulated in HCC tissues, and correlated with poor prognosis. Overexpression of CLDN1 dramatically promoted the capability of tumorsphere formation and cancer stem cell (CSC) traits. Furthermore, we found that TMPRSS4 was up-regulated in HCC tissues and there was a positive correlation between TMPRSS4 and CLDN1. In addition, the expression of CLDN1 was regulated by TMPRSS4. Moreover, TMPRSS4 mediated CSC properties and up-regulated CLDN1 by activating ERK1/2 signaling pathway. Taken together, our results revealed that CLDN1 contributed to CSC features of HCC, which was altered by TMPRSS4 expression via ERK1/2 signaling pathway, providing promising targets for novel specific therapies.

272 - TMPRSS4 expression enhances cancer stem cell-like properties in lung cancer cells and correlates with a CSC phenotype in NSCLC patients

272 - TMPRSS4 expression enhances cancer stem cell-like properties in lung cancer cells and correlates with a CSC phenotype in NSCLC patients

TMPRSS4: a novel serine protease involved in IPF development?

BackgroundIdiopathic pulmonary fibrosis (IPF) is a chronic, progressive and lethal lung disease characterized by the expansion of the fibroblast population and excessive extracellular matrix accumulation with the subsequent destruction of the lung architecture. Its pathogenesis is incompletely understood but evidence suggests an epithelial pathway in which IPF may result from epithelial microinjuries and activation and abnormal wound healing. TMPRSS4 is a novel type II transmembrane serine protease found at the cell surface. Although their biological functions are unknown it has been suggested that TMPRSS4 promotes migration and facilitates the epithelial to mesenchymal transition (EMT), two critical processes in the pathogenesis of IPF. Thus, we hypothesized that overexpression of TMPRSS4 in the lung could promote the initiation and/or progression of IPF.AimTo determine the role of TMPRSS4 in IPF.MethodsWe first examined the lung expression and localization of TMPRSS4 in IPF and normal lungs by qPCR and immunohistochemistry. Additionally, we measured the expression of TMPRSS4 in human lung fibroblasts and one alveolar and one bronchial epithelial cell lines. Then we explored the role of this protease in an experimental model of lung fibrosis. TMPRSS4 haplodeficient and wild type mice received an intratracheal instillation of bleomycin and were studied at 28 days post‐instillation.ResultsWe found that this protease is not expressed in normal human lungs while variable amounts of the mRNA were found in IPF lungs (2−DCT 1.1×10−2 ± 9.4×10−5). TMPRSS4 was primarily expressed by epithelial and mast cells. The protease was not found in lung fibroblasts but different levels of mRNA were revealed in alveolar (2−DCT 7.5×10−7 ± 2×10−7) and bronchial (2−DCT 4.2×10−5 ± 3.6×10−6) epithelial cells. The lung fibrotic response, measured by hydroxyproline ( 178.9 ± 12.4 versus 110.7 ± 13.8 mg/lung; p<0.05) and morphology (40% versus 15% extent of the lesions) was significantly attenuated in the haplodeficient mice.ConclusionsOur findings indicate that TMPRSS4 may have a profibrotic role in IPF and other fibrotic lung disorders.Support or Funding InformationPosgrado en Ciencias Biológicas, UNAM; CONACYT SALUD‐2014‐01‐234088

Epigenetic alterations leading to TMPRSS4 promoter hypomethylation and protein overexpression predict poor prognosis in squamous lung cancer patients.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide, which highlights the need of innovative therapeutic options. Although targeted therapies can be successfully used in a subset of patients with lung adenocarcinomas (ADC), they are not appropriate for patients with squamous cell carcinomas (SCC). In addition, there is an unmet need for the identification of prognostic biomarkers that can select patients at risk of relapse in early stages. Here, we have used several cohorts of NSCLC patients to analyze the prognostic value of both protein expression and DNA promoter methylation status of the prometastatic serine protease TMPRSS4. Moreover, expression and promoter methylation was evaluated in a panel of 46 lung cancer cell lines. We have demonstrated that a high TMPRSS4 expression is an independent prognostic factor in SCC. Similarly, aberrant hypomethylation in tumors, which correlates with high TMPRSS4 expression, is an independent prognostic predictor in SCC. The inverse correlation between expression and methylation status was also observed in cell lines. In vitro studies showed that treatment of cells lacking TMPRSS4 expression with a demethylating agent significantly increased TMPRSS4 levels. In conclusion, TMPRSS4 is a novel independent prognostic biomarker regulated by epigenetic changes in SCC and a potential therapeutic target in this tumor type, where targeted therapy is still underdeveloped.

TMPRSS4 induces cancer stem cell-like properties in lung cancer cells and correlates with ALDH expression in NSCLC patients

Metastasis involves a series of changes in cancer cells that promote their escape from the primary tumor and colonization to a new organ. This process is related to the transition from an epithelial to a mesenchymal phenotype (EMT). Recently, some authors have shown that migratory cells with an EMT phenotype share properties of cancer stem cells (CSCs), which allow them to form a new tumor mass. The type II transmembrane serine protease TMPRSS4 is highly expressed in some solid tumors, promotes metastasis and confers EMT features to cancer cells. We hypothesized that TMPRSS4 could also provide CSC properties. Overexpression of TMPRSS4 reduces E-cadherin and induces N-cadherin and vimentin in A549 lung cancer cells, supporting an EMT phenotype. These changes are accompanied by enhanced migration, invasion and tumorigenicity in vivo. TMPRSS4 expression was highly increased in a panel of lung cancer cells cultured as tumorspheres (a typical assay to enrich for CSCs). H358 and H441 cells with knocked-down TMPRSS4 levels were significantly less able to form primary and secondary tumorspheres than control cells. Moreover, they showed a lower proportion of ALDH+ cells (examined by FACS analysis) and lower expression of some CSC markers than controls. A549 cells overexpressing TMPRSS4 conferred the opposite phenotype and were also more sensitive to the CSC-targeted drug salinomycin than control cells, but were more resistant to regular chemotherapeutic drugs (cisplatin, gemcitabine and 5-fluorouracil). Analysis of 70 NSCLC samples from patients revealed a very significant correlation between TMPRSS4 expression and CSC markers ALDH (p = 0.0018) and OCT4 (p = 0.0004), suggesting that TMPRSS4 is associated with a CSC phenotype in patients' tumors. These results show that TMPRSS4, in addition to inducing EMT, can also promote CSC features in lung cancer; therefore, CSC-targeting drugs could be an appropriate treatment for TMPRSS4+ tumors.

TMPRSS4 facilitates epithelial-mesenchymal transition of hepatocellular carcinoma and is a predictive marker for poor prognosis of patients after curative resection.

TMPRSS4 (Transmembrane protease serine 4) is up-regulated in a broad spectrum of cancers. However, little is known about the biological effects of TMPRSS4 on hepatocellular carcinoma (HCC) and the related mechanisms. In the present study, we found that overexpression of TMPRSS4 significantly promoted the invasion, migration, adhesion and metastasis of HCC. Further more, TMPRSS4 induced EMT of HCC, which was mediated via snail and slug as a result of Raf/MEK/ERK1/2 activation, and inhibition of ERK1/2 activation by its inhibitor was associated with reduced cell invasion and reversion of EMT. In addition, we demonstrated that TMPRSS4 remarkably suppressed the expression of RECK, an inhibitor of angiogenesis, and drastically induced tumor angiogenesis and growth. More important, in clinical HCC specimens, TMPRSS4 expression was significantly correlated with tumor staging and was inversely correlated with E-cadherin and RECKS expression. Expression of TMPRSS4 is significantly associated with HCC progression and is an independent prognostic factor for postoperative worse survival and recurrence. In conclusion, TMPRSS4 functions as a positive regulator of Raf/MEK/ERK1/2 pathway and promotes HCC progression by inducing EMT and angiogenesis. The increase of TMPRSS4 expression may be a key event for HCC progression and may be regarded as a potential prognostic marker for HCC.

Abstract A71: TMPRSS4 proteolytically activates pro-uPA to induce cancer cell invasion

Abstract The invasive nature of tumor cells is critical for cancer metastasis. Urokinase-type plasminogen activator (uPA), which is usually derived from stromal cells, is a well-known serine protease involved in invasion and metastasis. uPA is produced as an inactive single-chain protein (known as pro-uPA or sc-uPA) that is processed into the active disulfide-linked two-chain form of uPA by a proteolytic event. TMPRSS4 is a novel type II transmembrane serine protease that is highly expressed on the cell surface in pancreatic, thyroid, colon, and other cancer tissues. Previously, we demonstrated that TMPRSS4 mediates colorectal tumor cell invasion, migration, and metastasis and increased TMPRSS4 expression is associated with colorectal cancer progression. We also demonstrated that TMPRSS4 upregulates uPA gene expression through c-Jun N-terminal kinase signaling activation to induce cancer cell invasion. However, it remains unknown how proteolytic activity of TMPRSS4 contributes to invasion. Here, we report that TMPRSS4 directly converted inactive pro-uPA into the active form through its proteolytic activity. Analysis of conditioned medium from cells overexpressing TMPRSS4 demonstrated that the active TMPRSS4 protease domain is released from the cells and is associated with the plasma membrane. Furthermore, TMPRSS4 could increase pro-uPA-mediated invasion in a serine proteolytic activity-dependent manner. These observations suggest that TMPRSS4 is an upstream regulator of invasion through the regulation of uPA. This study provides valuable insights into the proteolytic function of TMPRSS4 as well as mechanisms for the control of invasion. Citation Format: Hye-Jin Min, Semi Kim. TMPRSS4 proteolytically activates pro-uPA to induce cancer cell invasion. [abstract]. In: Abstracts: AACR Special Conference on Cellular Heterogeneity in the Tumor Microenvironment; 2014 Feb 26-Mar 1; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(1 Suppl):Abstract nr A71. doi:10.1158/1538-7445.CHTME14-A71

TMPRSS4 regulates levels of integrin α5 in NSCLC through miR-205 activity to promote metastasis

Background:TMPRSS4 is a membrane-anchored protease involved in cell migration and invasion in different cancer types including lung cancer. TMPRSS4 expression is increased in NSCLC and its inhibition through shRNA reduces lung metastasis. However, molecular mechanisms leading to the protumorigenic regulation of TMPRSS4 in lung cancer are unknown.Methods:miR-205 was identified as an overexpressed gene upon TMPRSS4 downregulation through microarray analysis. Cell migration and invasion assays and in vivo lung primary tumour and metastasis models were used for functional analysis of miR-205 overexpression in H2170 and H441 cell lines. Luciferase assays were used to identify a new miR-205 direct target in NSCLC.Results:miR-205 overexpression promoted an epithelial phenotype with increased E-cadherin and reduced fibronectin. Furthermore, miR-205 expression caused a G0/G1 cell cycle arrest and inhibition of cell growth, migration, attachment to fibronectin, primary tumour growth and metastasis formation in vivo. Integrin α5 (a proinvasive protein) was identified as a new miR-205 direct target in NSCLC. Integrin α5 downregulation in lung cancer cells resulted in complete abrogation of cell migration, a decreased capacity to adhere to fibronectin and reduced in vivo tumour growth, compared with control cells. TMPRSS4 silencing resulted in a concomitant reduction of integrin α5 levels.Conclusion:We have demonstrated for the first time a new molecular pathway that connects TMPRSS4 and integrin α5 through miR-205 to regulate cancer cell invasion and metastasis. Our results will help designing new therapeutic strategies to inhibit this novel pathway in NSCLC.

TMPRSS4 induces cancer cell invasion through pro-uPA processing

TMPRSS4 is a novel type II transmembrane serine protease that is highly expressed on the cell surface in pancreatic, thyroid, colon, and other cancer tissues. Previously, we demonstrated that TMPRSS4 mediates cancer cell invasion, epithelial-mesenchymal transition, and metastasis and that increased TMPRSS4 expression correlates with colorectal cancer progression. We also demonstrated that TMPRSS4 upregulates urokinase-type plasminogen activator (uPA) gene expression to induce cancer cell invasion. However, it remains unknown how proteolytic activity of TMPRSS4 contributes to invasion. In this study, we report that TMPRSS4 directly converted inactive pro-uPA into the active form through its proteolytic activity. Analysis of conditioned medium from cells overexpressing TMPRSS4 demonstrated that the active TMPRSS4 protease domain is released from the cells and is associated with the plasma membrane. Furthermore, TMPRSS4 could increase pro-uPA-mediated invasion in a serine proteolytic activity-dependent manner. These observations suggest that TMPRSS4 is an upstream regulator of pro-uPA activation. This study provides valuable insights into the proteolytic function of TMPRSS4 as well as mechanisms for the control of invasion.

Expression of TMPRSS4 in patients with salivary adenoid cystic carcinoma: correlation with clinicopathological features and prognosis

Although there is growing evidence supporting the hypothesis that TMPRSS4 is linked with cancer susceptibility, the precise role of TMPRSS4 expression in salivary adenoid cystic carcinoma (SACC) is still unknown. The aim of this study was to examine TMPRSS4 expression in SACC and determine its associations with clinicopathological features and survival. TMPRSS4 expression in 125 SACC tissue and adjacent non-cancerous tissues was analyzed by immunohistochemistry and Western blotting. In addition, the correlation of TMPRSS4 expression with clinicopathological variables was evaluated. The prognostic value of TMPRSS4 for overall survival (OS) and disease-free survival (DFS) was determined by Kaplan-Meier estimates, and the significance of differences between curves was evaluated by the log-rank test. We found that high TMPRSS4 expression was predominantly observed in SACC tissues, but not in the adjacent normal salivary gland tissues. High TMPRSS4 expression in SACC tissues was correlated significantly with tumor TNM stage (P = 0.016), lymph node metastasis (P = 0.002) and distant metastasis (P < 0.001). While high TMPRSS4 expression was associated with poor OS (P = 0.019) and DFS (P = 0.031), Cox regression analysis also revealed that TMPRSS4 was an independent predictor of OS and DFS. These findings suggested that TMPRSS4 was involved in the pathogenesis of SACC and might indicate a poor prognosis for SACC patients.

Abstract A096: MT-SP2/TMPRSS4 upregulates uPA gene expression through JNK signaling activation to induce cancer cell invasion

Abstract The invasive nature of tumor cells is critical for cancer metastasis. Urokinase-type plasminogen activator (uPA) is a well-known serine protease involved in normal tissue remodeling, such as wound healing, and in pathological events, such as invasion and metastasis. Increased levels of uPA correlate with invasive properties and poor prognosis in breast, lung, stomach, bladder, colon, prostate and ovarian cancers. MT-SP2/TMPRSS4 is a novel type II transmembrane serine protease that is highly expressed in pancreatic, colon, and other cancer tissues. Previously, we demonstrated that MT-SP2/TMPRSS4 mediates tumor cell invasion, migration, and metastasis. However, the mechanisms by which MT-SP2/TMPRSS4 contributes to invasion are not fully understood. Here, we demonstrated that MT-SP2/TMPRSS4 induced the transcription of the uPA gene through activating the transcription factors Sp1, Sp3, and AP-1 in mainly a JNK-dependent manner and that the induction of uPA was required for MT-SP2/TMPRSS4-mediated cancer cell invasion and signaling events. In addition, the uPA receptor was involved in MT-SP2/TMPRSS4-induced signaling activation and subsequent uPA expression probably through its association with TMPRSS4 on the cell surface. Immunohistochemical analysis showed that uPA expression was significantly correlated with MT-SP2/TMPRSS4 expression in human carcinomas. These observations suggest that MT-SP2/TMPRSS4 is an important regulator of uPA gene expression; the upregulation of uPA by TMPRSS4 contributes to invasion and may represent a novel mechanism for the control of invasion. Citation Format: Yunhee Lee, Hye-Jin Min, Hana Lee, Xue-Feng Zhao, Young-Kyu Park, Semi Kim. MT-SP2/TMPRSS4 upregulates uPA gene expression through JNK signaling activation to induce cancer cell invasion. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr A096.

High TMPRSS4 expression is a predictor of poor prognosis in cervical squamous cell carcinoma

Objective The aim of this study was to clarify the clinical role of TMPRSS4 expression in cervical squamous cell carcinoma (CSCC) and to investigate the role of TMPRSS4 in predicting outcomes of patients with CSCC. Methods The retrospective study enrolled 87 patients diagnosed with CSCC between 2004 and 2006. TMPRSS4 expression in CSCC was assessed by immunohistochemistry, and data on clinical variables were collected by retrospective chart review. The impact of TMPRSS4 expression on 5-year disease-free survival (DFS) and 5-year overall survival (OS) was assessed by Kaplan–Meier analysis and Cox proportional hazards modeling. Results The high expression of TMPRSS4 was 63.2% in 87 patients with CSCC, and 17.5% in 40 patients with benign cervical disease (P<0.001). High TMPRSS4 expression was significantly associated with tumor grade (P=0.005), lymph node metastasis (P=0.004), and deep cervical stromal invasion (P=0.025). Patients with high expression of TMPRSS4 had shorter OS and DFS than those with low expression (P=0.0205 and P=0.0318, respectively). In multivariate Cox regression analysis, high expression of TMPRSS4 was a potential prognostic indicator for OS (P=0.041) and DFS (P=0.015). Conclusion Our findings suggest that TMPRSS4 might play an important role in the progression of CSCC. TMPRSS4 could be a potential prognostic marker of CSCC.

TMPRSS4 upregulates uPA gene expression through JNK signaling activation to induce cancer cell invasion

TMPRSS4 is a novel type II transmembrane serine protease that is highly expressed in pancreatic, thyroid, colon, and other cancer tissues. Previously, we demonstrated that TMPRSS4 mediates tumor cell invasion, migration, and metastasis. However, the mechanisms by which TMPRSS4 contributes to invasion are not fully understood. Here, we demonstrated that TMPRSS4 induced the transcription of the urokinase-type plasminogen activator (uPA) gene through activating the transcription factors Sp1, Sp3, and AP-1 in mainly a JNK-dependent manner and that the induction of uPA was required for TMPRSS4-mediated cancer cell invasion and signaling events. In addition, the uPA receptor was involved in TMPRSS4-induced signaling activation and subsequent uPA expression probably through its association with TMPRSS4 on the cell surface. Immunohistochemical analysis showed that uPA expression was significantly correlated with TMPRSS4 expression in human lung and prostate cancers. These observations suggest that TMPRSS4 is an important regulator of uPA gene expression; the upregulation of uPA by TMPRSS4 contributes to invasion and may represent a novel mechanism for the control of invasion.

Expression and clinical significance of transmembrane serine protease 4 in primary hepatocellular carcinoma

Objective To investigate the expression and its clinical significance of transmembrane serine protease 4 (TMPRSS4) in primary hepatocellular carcinoma (PHC).Methods Immunohistochemistry was applied to detect the TMPRSS4 expression levels in 30 normal liver tissues,30 cirrhosis liver tissues and 121 PHC tissues.The correlation between the TMPRSS4 expression and clinicopathologic factors was analyzed in the PHC tissues.Results The high positive rate of TMPRSS4 in PHC,cirrhosis liver and normal tissues was 70.3％,26.7％ and 0,respectively,with the difference being statistically significant (P＜ 0.01).The expression levels of TMPRSS4 in PHC tissues were correlated with TNM stages and lymph node metastasis (P ＜ 0.05).Conclusion The expression levels of TMPRSS4 is closely correlated with the formation and development of PHC. Key words: Carcinoma, hepatocellular ; Transmembrane serine protease 4 ; Immunohistochemistry

Abstract 2696: TMPRSS4 regulates levels of integrin alpha-5 in NSCLC through miR-205 activity.

Abstract TMPRSS4 is a membrane-anchored protease involved in cell migration and invasion in different cancer types including lung cancer. We have previously shown that TMPRSS4 expression is increased in NSCLC and that its inhibition through shRNA reduces lung metastasis. The goal of the present study was to elucidate molecular mechanisms involved in the protumorigenic role of TMPRSS4 in NSCLC. A knock down strategy and microarray analyses were established to identify genes regulated by TMPRSS4. Among other genes, miR-205 was identified as an overexpressed gene upon TMPRSS4 downregulation. Levels of miR-205 were found to be reduced in NSCLC cells compared to non-malignant cells. miR-205 overexpression promoted the acquisition of an epithelial phenotype with increased E-cadherin and reduced fibronectin expression, probably through the regulation of transcription factors ZEB1 and ZEB2. Furthermore, miR-205 inhibited very significantly (p&amp;lt;0.01) tumor cell migration, invasion and metastasis formation in vivo. A further transcriptional and luciferase assays in miR-205-overexpressing cells identified integrin alpha-5 (a proinvasive protein overexpressed in tumors) as a new miR-205 target in NSCLC. We have therefore demonstrated for the first time a new molecular connection between TMPRSS4 and integrin alpha-5 through miR-205. Citation Format: Leyre Larzabal, Miriam Redrado, Arrate Lopez de Aberasturi, Paloma Rueda, Maria J. Rodriguez, Lissette Lopez, Luis Montuenga, Alfonso Calvo. TMPRSS4 regulates levels of integrin alpha-5 in NSCLC through miR-205 activity. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2696. doi:10.1158/1538-7445.AM2013-2696

TMPRSS4 is a type II transmembrane serine protease involved in cancer and viral infections

Proteolytic enzymes are involved in almost all biological processes reflecting their importance in health and disease. The human genome contains nearly 600 protease-encoding genes forming more than 2% of the total human proteome. The serine proteases, with about 180 members, built the oldest and second largest family of human proteases. Ten years ago, a novel serine protease family named the type II transmembrane family (TTSP) was identified. This minireview summarizes the up-to-date knowledge about the still growing TTSPs, particularly focusing on the pathophysiological functions of the family member type II transmembrane serine protease (TMPRSS) 4. Recent studies provided important data on TMPRSS4 activity associated with the spreading of influenza viruses, mediated by the cleavage of hemagglutinin. Progression and metastatic potential of several cancers is concordant with an increased expression of TMPRSS4, though being a possible diagnostic marker. However, to benefit from TMPRSS4 as a therapeutic target, more data concerning its physiological relevance are needed, as done by a specific morpholino knockdown in zebrafish embryos.

Expression of TMPRSS4 in non-small cell lung cancer and its modulation by hypoxia

Overexpression of TMPRSS4, a cell surface-associated transmembrane serine protease, has been reported in pancreatic, colorectal and thyroid cancers, and has been implicated in tumor cell migration and metastasis. Few reports have investigated both TMPRSS4 gene expression levels and the protein products. In this study, quantitative RT-PCR and protein staining were used to assess TMPRSS4 expression in primary non-small cell lung carcinoma (NSCLC) tissues and in lung tumor cell lines. At the transcriptional level, TMPRSS4 message was significantly elevated in the majority of human squamous cell and adenocarcinomas compared with normal lung tissues. Staining of over 100 NSCLC primary tumor and normal specimens with rabbit polyclonal anti-TMPRSS4 antibodies confirmed expression at the protein level in both squamous cell and adenocarcinomas with little or no staining in normal lung tissues. Human lung tumor cell lines expressed varying levels of TMPRSS4 mRNA in vitro. Interestingly, tumor cell lines with high levels of TMPRSS4 mRNA failed to show detectable TMPRSS4 protein by either immunoblotting or flow cytometry. However, protein levels were increased under hypoxic culture conditions suggesting that hypoxia within the tumor microenvironment may upregulate TMPRSS4 protein expression in vivo. This was supported by the observation of TMPRSS4 protein in xenograft tumors derived from the cell lines. In addition, staining of human squamous cell carcinoma samples for carbonic anhydrase IX (CAIX), a hypoxia marker, showed TMPRSS4 positive cells adjacent to CAIX positive cells. Overall, these results indicate that the cancer-associated TMPRSS4 protein is overexpressed in NSCLC and may represent a potential therapeutic target.

Overexpression of TMPRSS4 in non-small cell lung cancer is associated with poor prognosis in patients with squamous histology

Background:Mortality rates in lung cancer patients have not decreased significantly in recent years, even with the implementation of new therapeutic regimens. One of the main problems is that a large proportion of patients present local or distant metastasis at the time of diagnosis. The need for identification of novel biomarkers and therapeutic targets for a more effective management of lung cancer led us to investigate TMPRSS4, a protease reported to promote tumour growth and metastasis.Material and methods:In all, 34 lung cancer cell lines were used to evaluate the TMPRSS4 expression. Cell migration and clonogenic assays, and an in-vivo lung metastasis model were used for functional analysis of the TMPRSS4 downregulation in H358, H441 and H2170 cell lines. The TMPRSS4 expression analysis in normal and malignant lung tissue samples was performed by qPCR. Five different microarray-based publicly available expression databases were used to validate our results and to study prognosis.Results:The TMPRSS4 knock down in H358, H441 and H2170 cells resulted in a significant reduction in proliferation, clonogenic capacity and invasion. A significant (P<0.05) decrease in the lung colonisation and growth was found when mice were injected with TMPRSS4-depleated H358-derived clones, as compared with controls. Expression of TMPRSS4 showed a >30-fold increase (P<0.001) in tumours in comparison with non-malignant samples. Levels in tumours with squamous cell carcinoma (SCC) histology were found to be significantly higher (P<0.001) than those with adenocarcinoma (AC) histology, which was confirmed in data retrieved from the microarrays. Kaplan–Meier curves demonstrated that high levels of TMPRSS4 were significantly associated (P=0.017) with reduced overall survival in the patients with SCC histology, whereas no correlation was found for the AC histology.Conclusion:Our results demonstrate that TMPRSS4 has a role in the lung cancer development. The potential use of TMPRSS4 as a biomarker for lung cancer detection or as a predictor of patient's outcome warrants further investigation.

TMPRSS2 and TMPRSS4 Facilitate Trypsin-Independent Spread of Influenza Virus in Caco-2 Cells

Proteolysis of influenza virus hemagglutinin by host cell proteases is essential for viral infectivity, but the proteases responsible are not well defined. Recently, we showed that engineered expression of the type II transmembrane serine proteases (TTSPs) TMPRSS2 and TMPRSS4 allows hemagglutinin (HA) cleavage. Here we analyzed whether TMPRSS2 and TMPRSS4 are expressed in influenza virus target cells and support viral spread in the absence of exogenously added protease (trypsin). We found that transient expression of TMPRSS2 and TMPRSS4 resulted in HA cleavage and trypsin-independent viral spread. Endogenous expression of TMPRSS2 and TMPRSS4 in cell lines correlated with the ability to support the spread of influenza virus in the absence of trypsin, indicating that these proteases might activate influenza virus in naturally permissive cells. Indeed, RNA interference (RNAi)-mediated knockdown of both TMPRSS2 and TMPRSS4 in Caco-2 cells, which released fully infectious virus without trypsin treatment, markedly reduced the spread of influenza virus, demonstrating that these proteases were responsible for efficient proteolytic activation of HA in this cell line. Finally, TMPRSS2 was found to be coexpressed with the major receptor determinant of human influenza viruses, 2,6-linked sialic acids, in human alveolar epithelium, indicating that viral target cells in the human respiratory tract express TMPRSS2. Collectively, our results point toward an important role for TMPRSS2 and possibly TMPRSS4 in influenza virus replication and highlight the former protease as a potential therapeutic target.

TMPRSS4 induces invasion and epithelial-mesenchymal transition through upregulation of integrin 5 and its signaling pathways

TMPRSS4 is a novel type II transmembrane serine protease that is highly expressed on the cell surface in pancreatic, thyroid and other cancer tissues, although its oncogenic significance and molecular mechanisms are unknown. Previously, we have shown that TMPRSS4 promotes invasion, migration and metastasis of human tumor cells by facilitating an epithelial-mesenchymal transition (EMT). In this study, we explored the molecular basis underlying TMPRSS4-mediated effects. We show that multiple downstream signaling pathways, including focal adhesion kinase (FAK), extracellular signal-regulated kinase (ERK), Akt, Src and Rac1, are activated by TMPRSS4 expression and that FAK signaling and ERK activation are required for TMPRSS4-induced invasiveness and EMT, including cadherin switch. Inhibition of PI3K or Src reduced invasiveness and actin rearrangement mediated by TMPRSS4 without restoring E-cadherin expression. Downregulation of E-cadherin was required for TMPRSS4-mediated effects but was not sufficient to induce EMT and invasion. TMPRSS4 induced integrin alpha5 expression and its signal transduction, leading to invasiveness and EMT accompanied by downregulation of E-cadherin. Functional blocking confirmed that integrin alpha5beta1 is a critical signaling molecule that is sufficient to induce TMPRSS4-mediated effects. Immunohistochemical analysis showed that TMPRSS4 expression was significantly higher in human colorectal cancer tissues from advanced stages than in that of early stage. Furthermore, upregulation of TMPRSS4 was correlated with enhanced integrin alpha5 expression. These observations implicate integrin alpha5 upregulation as a molecular mechanism by which TMPRSS4 induces invasion and contributes to cancer progression.