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

TMPRSS4 Promotes Cell Proliferation and Inhibits Apoptosis in Pancreatic Ductal Adenocarcinoma by Activating ERK1/2 Signaling Pathway

Transmembrane protease serine 4 (TMPRSS4) is upregulated in various kinds of human cancers, including pancreatic cancer. However, its biological function in pancreatic ductal adenocarcinoma (PDAC) remains unclear. In the current study, real-time qPCR, immunohistochemical staining, Western blotting, and database (Cancer Genome Atlas and Gene Expression) analysis revealed remarkable overexpression of TMPRSS4 in PDAC tissue as compared to non-tumor tissue. The TMPRSS4 overexpression was associated with poor prognosis of PDAC patients. Moreover, multivariate analysis revealed that TMPRSS4 serves as an independent risk factor in PDAC. We performed gain-and loss-of-function analysis and found that TMPRSS4 promotes cellular proliferation and inhibits apoptosis of PDAC cells both in vitro and in vivo. Furthermore, we showed that TMPRSS4 might promote cell proliferation and inhibit apoptosis through activating ERK1/2 signaling pathway in pancreatic cancer cells. These findings were validated by using ERK1/2 phosphorylation inhibitor SCH772984 both in vitro and in vivo. Taken together, this study suggests that TMPRSS4 is a proto-oncogene, which promotes initiation and progression of PDAC by controlling cell proliferation and apoptosis. Our findings indicate that TMPRSS4 could be a promising prognostic biomarker and a therapeutic target for the treatment of pancreatic cancer.

TMPRSS4 as an emerging potential poor prognostic factor for solid tumors: A systematic review and meta-analysis

Recent studies have investigated the potential prognostic value of the transmembrane protease serine 4 (TMPRSS4) in various solid tumors. Yet, the results are inconclusive. Here, we performed this meta-analysis to clarify this issue. Relevant articles were identified by searching PubMed, Web of Science and Embase databases. The primary outcome endpoints were patients' overall survival (OS) and time to tumor progression (TTP). Twelve studies involving 1,955 participants were included. We showed that high TMPRSS4 expression in tumor tissues was significantly associated with patients' poor OS (pooled HR = 2.981, 95% CI = 2.296-3.869, P < 0.001) and short TTP (pooled HR = 2.456, 95% CI = 1.744-3.458, P < 0.001). A subgroup analysis revealed that the association between TMPRSS4 and the outcome endpoints (OS or TTP) was also significant within China region. We conclude that TMPRSS4 overexpression in solid tumors is associated with patients' poor prognosis. TMPRSS4 could be a valuable prognosis biomarker or a promising therapeutic target of solid tumor.

Epithelial Sodium Channel-Mediated Sodium Transport Is Not Dependent on the Membrane-Bound Serine Protease CAP2/Tmprss4

The membrane-bound serine protease CAP2/Tmprss4 has been previously identified in vitro as a positive regulator of the epithelial sodium channel (ENaC). To study its in vivo implication in ENaC-mediated sodium absorption, we generated a knockout mouse model for CAP2/Tmprss4. Mice deficient in CAP2/Tmprss4 were viable, fertile, and did not show any obvious histological abnormalities. Unexpectedly, when challenged with sodium-deficient diet, these mice did not develop any impairment in renal sodium handling as evidenced by normal plasma and urinary sodium and potassium electrolytes, as well as normal aldosterone levels. Despite minor alterations in ENaC mRNA expression, we found no evidence for altered proteolytic cleavage of ENaC subunits. In consequence, ENaC activity, as monitored by the amiloride-sensitive rectal potential difference (ΔPD), was not altered even under dietary sodium restriction. In summary, ENaC-mediated sodium balance is not affected by lack of CAP2/Tmprss4 expression and thus, does not seem to directly control ENaC expression and activity in vivo.

Distant Metastases in Patients with Carcinoma of the Major Salivary Glands

BACKGROUND

This study aimed to show the incidence of distant metastases (DM) in salivary gland cancer as well as the types of histology most commonly associated with it and to identify factors predictive of DM.

METHODS

The study identified 301 patients who underwent surgery for cancer of the major salivary glands at Memorial Sloan-Kettering Cancer center between 1985 and 2009. Clinical, tumor, and treatment characteristics were recorded. Tumors were categorized as low-, intermediate-, and high-risk pathology based on histologic subtype and grade. Factors predictive of distant recurrence-free probability (DRFP) were determined by uni- and multivariable analyses.

RESULTS

The primary tumor was parotid in 266 patients (88 %), and 96 tumors (32 %) were clinical T3/T4. For 57 patients (18.9 %), DM developed with a 5-year DRFP of 72.7 %. The most common site of metastasis was the lung (50 %). The clinical predictors were male gender, cT4 stage, cN+ stage, and clinical overall stage. The multivariable analysis of clinical variables showed male gender (p = 0.018), cT4 stage (p < 0.001), and cN+ stage (p = 0.004) to be significant. The pathologic predictors were high-risk and high-grade pathology, vascular invasion, perineural invasion, positive margins, pT4 stage, pN+ stage, and overall stage. The multivariable analysis of pathologic variables showed high-grade pathology (p < 0.001), perineural invasion (p = 0.005), and pN+ stage (p = 0.002) to be significant.

CONCLUSIONS

Distant metastases developed in approximately 20 % of the patients with salivary gland cancer. The most common site of metastases was the lung. The significant predictors of DM were cT4, cN+, male gender, high-grade pathology, perineural invasion, and positive nodal disease.

TMPRSS4: an emerging potential therapeutic target in cancer

Altered expression and activity of proteases is a key event in cancer, particularly in relation to invasion, modification of the extracellular matrix and metastasis. The transmembrane protease, serine 4 (TMPRSS4) is closely related to other cancer-associated proteases, such as hepsin, TMPRSS2 and matriptase. We review in this study up-to-date information about expression, role, regulation and clinical relevance of TMPRSS4 in cancer. Increased expression of this protease is associated with acquisition of epithelial to mesenchymal transition, invasion and metastasis in vivo. Signalling in cancer cells involves upregulation of integrin-α5 (ITG-α5) and urokinase-type plasminogen activator (uPA), downregulation of E-cadherin and activation of uPA enzymatic activity at the plasma membrane, as well as phosphorylation of FAK, Src, Akt and ERK1/2 intracellularly. Upregulation of miR-205 hinders the protumorigenic effects elicited by TMPRSS4 through restoration of E-cadherin levels and direct targeting of ITG-α5. High levels of TMPRSS4 have been found in several types of solid tumours in patients, and association with poor prognosis has been consistently described. On the basis of this information and the structural characteristics of this druggable protease, we suggest that TMPRSS4 could be a novel potential therapeutic target in solid tumours.

Deregulation of Bmi-1 is associated with enhanced migration, invasion and poor prognosis in salivary adenoid cystic carcinoma

BACKGROUND

Bmi-1 had been found to involve in self renewal of stem cells and tumorigenesis in various malignancies. In this study, we investigated the role of Bmi-1 in the development of salivary adenoid cystic carcinoma (SACC).

METHODS

At first, we confirmed that the deregulation of Bmi-1 was a frequent event in SACC; up-regulation of Bmi-1 was correlated with clinical stages, vital status and distant metastasis and associated with reduced overall survival and disease free survival. SACC-LM cells, higher migration and invasion abilities, elevated the expression of Bmi-1 protein, epithelial-mesenchymal transition (EMT) related proteins (Snail, Slug and Vimentin) and cancer stem cells (CSCs) related proteins (ABCG2, Notch, ALDH-1, Oct-4, Nanog and Epcam) compared to the SACC-83 cells (lower migration and invasion abilities). The migration and invasion abilities were inhibited in SACC-LM cells upon Bmi-1 knockdown. Meanwhile, Bmi-1 knockdown resulted in simultaneous loss of stem cell markers and EMT markers in SACC-LM cells.

CONCLUSION

Our studies confirm that Bmi-1 deregulation plays an important role in the development of SACC and contributes to the migration and the invasion abilities of SACC, which is involved in EMT and CSCs.

GENERAL SIGNIFICANCE

To our knowledge, this is the first study revealing that Bmi-1 deregulation is associated with enhanced migration, invasion and poor prognosis in salivary adenoid cystic carcinoma.