Knockdown of circ_0076305 decreases the paclitaxel resistance of non-small cell lung cancer cells by regulating TMPRSS4 via miR-936.

Background: Paclitaxel (PTX) is a commonly used as a chemotherapeutic drug for non-small cell lung cancer (NSCLC). Exploring the underlying mechanism of PTX resistance is of great significance for NSCLC treatment. Methods: The expression levels of RNA and protein were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot assays. The targeted relationship was confirmed by dual-luciferase reporter assay and RNA-pull down assay. The PTX resistance and cell proliferation were assessed by cell counting kit-8 (CCK-8) assay and 5-Ethynyl-2'-deoxyuridine (EDU) assay, respectively. Cell migration and invasion were analyzed by transwell assays. Cell apoptosis was analyzed by flow cytometry, and cell glycolysis was analyzed using the commercial kits. The role of circular RNA_0076305 (circ_0076305) in regulating the PTX sensitivity in vivo was explored in xenograft tumor model. Results: Circ_0076305 was up-regulated in PTX-resistant NSCLC tissues and cells. Mechanically, circ_0076305 bound to microRNA-936 (miR-936), and miR-936 targeted transmembrane serine protease 4 (TMPRSS4). Circ_0076305 could up-regulate TMPRSS4 expression by sponging miR-936 in NSCLC cells. miR-936 knockdown or TMPRSS4 overexpression reversed the anti-tumor effects of circ_0076305 knockdown in NSCLC cells with PTX treatment. Circ_0076305 silencing increased the PTX sensitivity of xenograft tumors in vivo. Conclusion: Circ_0076305 silencing promoted PTX sensitivity by targeting miR-936/TMPRSS4 axis in NSCLC cells.

Effects of transmembrane serine protease 4 on the survival in patients with pancreatic ductal adenocarcinoma undergoing surgery followed by adjuvant chemotherapy.

PURPOSE: The transmembrane serine protease 4 (TMPRSS4) gene is upregulated in various human cancers. However, its biological functions in pancreatic ductal adenocarcinoma remain unclear. We examined the expression of TMPRSS4 in pancreatic ductal adenocarcinoma tissues and its correlation with clinicopathological parameters in patients with pancreatic ductal adenocarcinoma who underwent surgery. METHODS: The TMPRSS4 expression was immunohistochemically examined in 81 PDAC patients with pancreatic ductal adenocarcinoma. We analyzed the association between the TMPRSS4 expression and clinicopathological factors, the recurrence-free survival (RFS), and the overall survival (OS) and examined the effect of TMPRSS4 expression on cell migration and sensitivity to 5-fluorouracil. RESULTS: The expression rate of TMPRSS4 in the samples was 62.9% (51/81). The TMPRSS4 expression was not correlated with any clinicopathological feature. The five-year overall and recurrence-free survival rates were significantly lower in the TMPRSS4-positive group than in the TMPRSS4-negative group. On a multivariate analysis, TMPRSS4 positivity, poorly differentiated histology, and non-adjuvant chemotherapy predicted a poor OS, while TMPRSS4 positivity and poorly differentiated histology predicted a poor RFS. TMPRSS4-silenced pancreatic ductal adenocarcinoma cells showed higher sensitivity to 5- fluorouracil than did the control siRNA-transfected cells. CONCLUSIONS: TMPRSS4 can be considered a prognostic factor and therapeutic target for pancreatic ductal adenocarcinoma.

The expression profile of 79 genes from 107 viruses revealed new insights into disease susceptibility in rats, mice, and muskrats.

The coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly spread over the world, resulting in a global severe pneumonia pandemic. Both the cell receptor angiotensin-converting enzyme 2 (ACE2) and the breakdown of S protein by transmembrane serine protease 2 (TMPRSS2) are required by SARS-CoV-2 to enter the host cells. Similarly, the expression level of viral receptor genes in various organs determines the likelihood of viral infection. Several animal species have been found to be infected by the SARS-CoV-2, such as minks, posing an enormous threat to humans. Because the mice and rats were closely related to human and the fact that rats and mice have a risk of infection by SARS-CoV-2 with specific variants, we investigated the expression patterns of 79 receptor genes from 107 viruses, including SARS-CoV-2, in 14 organs of the rat and mouse, and 5 organs of the muskrat, to find the most likely host organs to become infected with certain viruses. The findings of this study are anticipated to aid in prevention of zoonotic infections spread by rats, mice, muskrats, and other rodents.

TMPRSS4 is a novel biomarker and correlated with immune infiltration in thyroid carcinoma.

Transmembrane protease serine 4 (TMPRSS4) is a cancer-associated protease associated with prognosis in various types of cancer. Mechanistically, TMPRSS4 mainly regulates malignant phenotypes, such as tumor invasion and metastasis, by either the epithelial to mesenchymal transition (EMT) program or promoting the proliferation of cancer cells. To date, TMPRSS4 and immune infiltration in thyroid carcinoma (TC) are largely unknown. Thus, this paper evaluated the expression of TMPRSS4 in tumor tissue through the Tumor Immune Estimation Resource (TIMER) database, and Oncomine, and its correlation with clinical parameters by UALCAN databases. Furthermore, we analyzed its prognostic value from Kaplan-Meier Plotter database, and the relationship between TMPRSS4 and the abundance of tumor-infiltrating lymphocytes (TILs) in TC in TISIDB, screening potential immune targets to explore novel mechanisms for the clinical management of TC. Finally, we assessed the correlation between TMPRSS4 and some immune markers to uncover a potential immune-related biomarker in TC patients by TIMER2.0. The results revealed that TMPRSS4 was highly expressed in TC and was also associated with lymphatic metastasis, advanced stage, histological subtype, and favorable clinical outcome. The stratified analysis based on immune cell content showed that decreased TMPRSS4 had worse prognosis in CD8+ T cell-enriched TC patients. TMPRSS4 was positively correlated with tumor immune infiltration and the expression of gene markers of immune cells. Notably, its expression was lower in the lymphocyte-depleted subtype than in other immunosubtypes in TC. Moreover, TMPRSS4 was closely related to chemokines as well as their receptors and the immunosuppressive checkpoints CTLA-4, PD-1, and HLA-G. In conclusion, TMPRSS4 may act as a novel biomarker predicting prognosis and immune infiltration in TC.

The lncRNA HOXA11-AS acts as a tumor promoter in breast cancer through regulation of the miR-125a-5p/TMPRSS4 axis.

BACKGROUND: Long non-coding RNAs (lncRNAs) play vital roles in tumorigenesis. Here, we explored how lncRNA HOXA11-AS functions in the progression of breast cancer (BC). METHODS: HOXA11-AS and miR-125a-5p levels were measured by a quantitative real-time polymerase chain reaction, whereas western blotting determined TMPRSS4 levels in BC tumor tissues, adjacent normal tissues and BC cell lines. The roles of HOXA11-AS, miR-125a-5p and TMPRSS4 in BC proliferation were investigated using cell counting kit-8, colony formation and flow cytometry assays, whereas scratch and transwell assays were used to measure metastasis. RNA pull-down assays and dual-luciferase assays assessed direct interactions between HOXA11-AS and miR-125a-5p. The effects of HOXA11-AS in vivo were investigated in a BC xenograft model. RESULTS: HOXA11-AS was upregulated in tumor tissues of 56 BC patients compared to adjacent non-tumor tissues, with high levels being associated with worse overall survival. Silencing of HOXA11-AS inhibited the proliferation and metastasis of BC cells, leading to cell cycle arrest in G0/G1 and induction of apoptosis. We identified miR-125a-5p as a target of HOXA11-AS, with miR-125a-5p inhibitors partially restoring the reduction of cell proliferation and metastasis induced by HOXA11-AS silencing. We also determined that miR-125a-5p targeted TMPRSS4 mRNA, with HOXA11-AS knockdown and miR-125a-5p mimics suppressing TMPRSS4. Overexpression of TMPRSS4 partially compensated for the reduction of cell proliferation and metastasis induced by HOXA11-AS silencing. Finally, we confirmed the mechanism of HOXA11-AS in the regulation of tumorigenesis in the mouse model. CONCLUSIONS: HOXA11-AS regulates the tumorigenic ability of BC via the miR-125a-5p/TMPRSS4 axis. This provides insights for regulatory mechanisms involved in BC progression, and may enable new treatment strategies in the clinical setting.

Host cell entry mediators implicated in the cellular tropism of SARS­CoV­2, the pathophysiology of COVID­19 and the identification of microRNAs that can modulate the expression of these mediators (Review).

The pathophysiology of coronavirus disease 2019 (COVID­19) is mainly dependent on the underlying mechanisms that mediate the entry of severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) into the host cells of the various human tissues/organs. Recent studies have indicated a higher order of complexity of the mechanisms of infectivity, given that there is a wide­repertoire of possible cell entry mediators that appear to co­localise in a cell­ and tissue­specific manner. The present study provides an overview of the 'canonical' SARS­CoV­2 mediators, namely angiotensin converting enzyme 2, transmembrane protease serine 2 and 4, and neuropilin­1, expanding on the involvement of novel candidates, including glucose­regulated protein 78, basigin, kidney injury molecule­1, metabotropic glutamate receptor subtype 2, ADAM metallopeptidase domain 17 (also termed tumour necrosis factor­α convertase) and Toll­like receptor 4. Furthermore, emerging data indicate that changes in microRNA (miRNA/miR) expression levels in patients with COVID­19 are suggestive of further complexity in the regulation of these viral mediators. An in silico analysis revealed 160 candidate miRNAs with potential strong binding capacity in the aforementioned genes. Future studies should concentrate on elucidating the association between the cellular tropism of the SARS­CoV­2 cell entry mediators and the mechanisms through which they might affect the clinical outcome. Finally, the clinical utility as a biomarker or therapeutic target of miRNAs in the context of COVID­19 warrants further investigation.

Utility of TMPRSS4 as a Prognostic Biomarker and Potential Therapeutic Target in Patients with Gastric Cancer.

BACKGROUND: Transmembrane serine protease 4 (TMPRSS4) belongs to the family of type II transmembrane serine proteases that are known to be upregulated in many malignant tumors. However, there is a paucity of studies documenting the clinical impact and biological effects of TMPRSS4 on gastric cancer (GC) patients who underwent surgery. METHODS: Tissues samples were obtained from 105 patients with GC who underwent gastrectomy followed by adjuvant chemotherapy, excluding those at stage I. The expression of TMPRSS4 was examined through immunohistochemical analysis. The association between TMPRSS4 expression and clinico-pathological features as well as prognosis was assessed. Moreover, the effects of TMPRSS4 expression on cell migration and sensitivity to 5-FU were investigated. RESULTS: The expression rate of TMPRSS4 was 56.3% (59/105) in GC cases. The expression of TMPRSS4 was positively correlated with the depth of tumor (T) and venous (V) invasion. The 5-year overall survival (OS) and recurrence-free survival (RFS) rates of the TMPRSS4-positive group was significantly lower than that of the TMPRSS4-negative group (p=0.0001 and p=0.005, respectively). Especially, there was significant differences in OS and RFS of patients with stage III cancer between the two groups (p=0.0064 and 0.012, respectively). Multivariate analysis demonstrated that TMPRSS4 expression and the stage of cancer were crucial prognostic factors for RFS. TMPRSS4-silenced GC cells exhibited increased sensitivity to 5-FU when compared with the non-specific control siRNA-transfected cells. CONCLUSION: TMPRSS4 can be considered as a potential prognostic biomarker, especially for stage III, and a promising therapeutic target for GC.

TMPRSS4 promotes cancer stem-like properties in prostate cancer cells through upregulation of SOX2 by SLUG and TWIST1.

BACKGROUND: Transmembrane serine protease 4 (TMPRSS4) is a cell surface-anchored serine protease. Elevated expression of TMPRSS4 correlates with poor prognosis in colorectal cancer, gastric cancer, prostate cancer, non-small cell lung cancer, and other cancers. Previously, we demonstrated that TMPRSS4 promotes invasion and proliferation of prostate cancer cells. Here, we investigated whether TMPRSS4 confers cancer stem-like properties to prostate cancer cells and characterized the underlying mechanisms. METHODS: Acquisition of cancer stem-like properties by TMPRSS4 was examined by monitoring anchorage-independent growth, tumorsphere formation, aldehyde dehydrogenase (ALDH) activation, and resistance to anoikis and drugs in vitro and in an early metastasis model in vivo. The underlying molecular mechanisms were evaluated, focusing on stemness-related factors regulated by epithelial-mesenchymal transition (EMT)-inducing transcription factors. Clinical expression and significance of TMPRSS4 and stemness-associated factors were explored by analyzing datasets from The Cancer Genome Atlas (TCGA). RESULTS: TMPRSS4 promoted anchorage-independent growth, ALDH activation, tumorsphere formation, and therapeutic resistance of prostate cancer cells. In addition, TMPRSS4 promoted resistance to anoikis, thereby increasing survival of circulating tumor cells and promoting early metastasis. These features were accompanied by upregulation of stemness-related factors such as SOX2, BMI1, and CD133. SLUG and TWIST1, master EMT-inducing transcription factors, made essential contributions to TMPRSS4-mediated cancer stem cell (CSC) features through upregulation of SOX2. SLUG stabilized SOX2 via preventing proteasomal degradation through its interaction with SOX2, while TWIST1 upregulated transcription of SOX2 by interacting with the proximal E-box element in the SOX2 promoter. Clinical data showed that TMPRSS4 expression correlated with the levels of SOX2, PROM1, SNAI2, and TWIST1. Expression of SOX2 was positively correlated with that of TWIST1, but not with other EMT-inducing transcription factors, in various cancer cell lines. CONCLUSIONS: Together, these findings suggest that TMPRSS4 promotes CSC features in prostate cancer through upregulation of the SLUG- and TWIST1-induced stem cell factor SOX2 beyond EMT. Thus, TMPRSS4/SLUG-TWIST1/SOX2 axis may represent a novel mechanism involved in the control of tumor progression.

TMPRSS4 overexpression promotes the metastasis of colorectal cancer and predicts poor prognosis of stage III-IV colorectal cancer.

PURPOSE: To study in detail the expression pattern and prognostic significance of TMPRSS4 in colorectal cancer. METHODS: The expression of TMPRSS4 protein was determined using Western blot in the colorectal cancer tissues and normal tissues. Immunohistochemistry was used to detect the TMPRSS4 expression in colorectal cancer tissues, and the clinicopathologic characteristics and prognostic significance were analyzed. RESULTS: TMPRSS4 overexpression was associated with tumor budding, lymphovascular invasion, perineural invasion, cancerous emboli, infiltration depth, lymph node metastasis, distant metastasis, and tumor node metastasis stage (P < 0.05 for all). Interestingly, TMPRSS4 expression in the tumor budding, tumor emboli, lymph node, and liver metastatic tumor samples was higher than in the paired primary tumors. In contrast, TMPRSS4 overexpression is inversely correlated with both the overall survival and the disease-free survival of the patients with colorectal cancer (P < 0.05 for both). Also, we found that TMPRSS4 is only of significance in predicting the prognosis of stage III and IV colorectal cancer, not stage I and II. CONCLUSIONS: TMPRSS4 was shown to be involved in the whole process of metastasis from tumor budding to lymph node and/or distant metastasis in colorectal cancer and predicted the unfavorable prognosis of stage III-IV, indicating that it is a novel target for the precise treatment of colorectal cancer with lymph node or distant organ metastasis.

Type II transmembrane serine proteases 4 (TMPRSS4) promotes proliferation, invasion and epithelial-mesenchymal transition in endometrial carcinoma cells (HEC1A and Ishikawa) via activation of MAPK and AKT.

Endometrial cancer is the most common gynecological cancer in the developed countries. Type II transmembrane serine proteases 4 (TMPRSS4) is a newly discovered transmembrane protein, which may be related to the invasion, metastasis of the tumor and the poor prognosis. This study aims to investigate the role of TMPRSS4 in endometrial cancer and the detailed molecular mechanism. The results showed that TMPRSS4 was highly expressed in human endometrial cancer cells (HEC1A and Ishikawa). TMPRSS4 knockdown inhibited proliferation of endometrial cancer cells. In TMPRSS4 knockdown cells, the invasion of cells was significantly supressed. The expression of E-cadherin was significantly enhanced, while the levels of fibronectin and vimentin decreased in TMPRSS4 knockdown cells, which indicated thatTMPRSS4 knockdown attenuated the EMT of cancer cells. TMPRSS4 positively regulated the activation of MAPK and AKT signaling pathways in endometrial cancer. In conclusion, this study indicated that TMPRSS4 may be associated with the progression of endometrial cancer through promoting proliferation, invasion and EMT via activation of MAPK and AKT in endometrial cancer cells. TMPRSS4 may be a new and more effective target or therapeutic strategy for treating endometrial cancer.

Characteristics of Angiotensin I-converting enzyme 2, type II transmembrane serine protease 2 and 4 in tree shrew indicate it as a potential animal model for SARS-CoV-2 infection.

Angiotensin I-converting enzyme 2 (ACE2), type II transmembrane serine protease 2 and 4 (TMPRSS2 and TMPRSS4) are important receptors for SARS-CoV-2 infection. In this study, the full-length tree shrewACE2 gene was cloned and sequenced, and its biological information was analyzed. The expression levels of ACE2, TMPRSS2 and TMPRSS4 in various tissues or organs of the tree shrew were detected. The results showed that the full-length ACE2 gene in tree shrews was 2,786 bp, and its CDS was 2,418 bp, encoding 805 amino acids. Phylogenetic analysis based on the CDS of ACE2 revealed that tree shrews were more similar to rabbits (85.93%) and humans (85.47%) but far from mice (82.81%) and rats (82.58%). In silico analysis according to the binding site of SARS-CoV-2 with the ACE2 receptor of different species predicted that tree shrews had potential SARS-CoV-2 infection possibility, which was similar to that of rabbits, cats and dogs but significantly higher than that of mice and rats. In addition, various tissues or organs of tree shrews expressed ACE2, TMPRSS2 and TMPRSS4. Among them, the kidney most highly expressed ACE2, followed by the lung and liver. The esophagus, lung, liver, intestine and kidney had relatively high expression levels of TMPRSS2 and TMPRSS4. In general, we reported for the first time the expression of ACE2, TMPRSS2 and TMPRSS4 in various tissues or organs in tree shrews. Our results revealed that tree shrews could be used as a potential animal model to study the mechanism underlying SARS-CoV-2 infection.

Transmembrane Protease TMPRSS4 Promotes the Formation and Development of Mismatch Repair Deficient Colon Cancer Liver Metastasis.

We studied metastasis-promoting effect of transmembrane protease TMPRSS4 on mismatch repair (MMR)-deficient colorectal cancer liver metastasis in BALB/c nude mouse model. Histomorphological and histopathological studies showed that the number of liver metastases in the study group were significantly higher than that in the control group (p<0.05). The expression of TMPRSS4 mRNA and protein in the study group were obviously higher than in the control group (p<0.05). These findings suggest that TMPRSS4 possesses a metastasis-promoting effect and its low expression can effectively block the progression of MMR-deficient colon cancer liver metastasis.

Inhibition of TMPRSS4 mediated epithelial-mesenchymal transition is critically involved in antimetastatic effect of melatonin in colorectal cancers.

In the current study, the underlying anti-metastatic mechanism of melatonin contained in some edible plants was explored in association with transmembrane protease serine 4 (TMPRSS4) mediated metastasis and epithelial-mesenchymal transition (EMT) signaling in human HCT15 and SW620 colorectal cancer cells. Here, TMPRSS4 was highly expressed in HCT15, but was weakly expressed in SW620 cells. Melatonin exerted weak cytotoxicity, decreased invasion, adhesion, and migration, and attenuated the expression of TMPRSS4, cyclin E, pro-urokinase-type plasminogen activator (pro-uPA), p-signal transducer and activator of transcription 3 (p-STAT3), p-focal adhesion kinase (p-FAK), Snail and increased the expression of E-cadherin, p27, pp38 and p-Jun N-terminal kinases (p-JNK) in HCT15 cells. Conversely, overexpression of TMPRSS4 reduced the ability of melatonin to activate E-cadherin and reduce Snail. Furthermore, even in SW620 cells transfected with TMPRSS4-overexpression plasmid, melatonin effectively suppressed invasion and migration along with decreased expression of Snail, cyclin A, cyclin E, pro-uPA and p-FAK and increased expression of E-cadherin and p27. Overall, these findings provide evidence that melatonin suppresses metastasis in colon cancer cells via inhibition of TMPRSS4 mediated EMT.

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.

Computationally predicted SARS-COV-2 encoded microRNAs target NFKB, JAK/STAT and TGFB signaling pathways.

Recently an outbreak that emerged in Wuhan, China in December 2019, spread to the whole world in a short time and killed >1,410,000 people. It was determined that a new type of beta coronavirus called severe acute respiratory disease coronavirus type 2 (SARS-CoV-2) was causative agent of this outbreak and the disease caused by the virus was named as coronavirus disease 19 (COVID19). Despite the information obtained from the viral genome structure, many aspects of the virus-host interactions during infection is still unknown. In this study we aimed to identify SARS-CoV-2 encoded microRNAs and their cellular targets. We applied a computational method to predict miRNAs encoded by SARS-CoV-2 along with their putative targets in humans. Targets of predicted miRNAs were clustered into groups based on their biological processes, molecular function, and cellular compartments using GO and PANTHER. By using KEGG pathway enrichment analysis top pathways were identified. Finally, we have constructed an integrative pathway network analysis with target genes. We identified 40 SARS-CoV-2 miRNAs and their regulated targets. Our analysis showed that targeted genes including NFKB1, NFKBIE, JAK1-2, STAT3-4, STAT5B, STAT6, SOCS1-6, IL2, IL8, IL10, IL17, TGFBR1-2, SMAD2-4, HDAC1-6 and JARID1A-C, JARID2 play important roles in NFKB, JAK/STAT and TGFB signaling pathways as well as cells' epigenetic regulation pathways. Our results may help to understand virus-host interaction and the role of viral miRNAs during SARS-CoV-2 infection. As there is no current drug and effective treatment available for COVID19, it may also help to develop new treatment strategies.

Inhibitors of type II transmembrane serine proteases in the treatment of diseases of the respiratory tract - A review of patent literature.

INTRODUCTION: Type II transmembrane serine proteases (TTSPs) of the human respiratory tract generate high interest owing to their ability, among other roles, to cleave surface proteins of respiratory viruses. This step is critical in the viral invasion of coronaviruses, including SARS-CoV-2 responsible for COVID-19, but also influenza viruses and reoviruses. Accordingly, these cell surface enzymes constitute appealing therapeutic targets to develop host-based therapeutics against respiratory viral diseases. Additionally, their deregulated levels or activity has been described in non-viral diseases such as fibrosis, cancer, and osteoarthritis, making them potential targets in these indications. AREAS COVERED: Areas covered: This review includes WIPO-listed patents reporting small molecules and peptide-based inhibitors of type II transmembrane serine proteases of the respiratory tract. EXPERT OPINION: Expert opinion: Several TTSPs of the respiratory tract represent attractive pharmacological targets in the treatment of respiratory infectious diseases (notably COVID-19 and influenza), but also against idiopathic pulmonary fibrosis and lung cancer. The current emphasis is primarily on TMPRSS2, matriptase, and hepsin, yet other TTSPs await validation. Compounds listed herein are predominantly peptidomimetic inhibitors, some with covalent reversible mechanisms of action and high potencies. Their selectivity profile, however, are often only partially characterized. Preclinical data are promising and warrant further advancement in the above diseases.

Smoking and COVID-19: Similar bronchial ACE2 and TMPRSS2 expression and higher TMPRSS4 expression in current versus never smokers.

Uncertainties remain concerning the pathophysiology, epidemiology, and potential therapeutics for COVID-19. Among unsettled controversies is whether tobacco smoking increases or protects from severe COVID-19. Several epidemiological studies reported reduced COVID-19 hospitalizations among smokers, while other studies reported the opposite trend. Some authors assumed that smokers have elevated airway expression of ACE2, the cell recognition site of the SARS-Cov-2 spike protein, but this suggestion remains unverified. We therefore performed data mining of two independent NCBI GEO genome-wide RNA expression files (GSE7894 and GSE994) and report that in both data sets, current smokers and never smokers have, on average, closely similar bronchial epithelial cell mRNA levels of ACE2, as well as TMPRSS2, coding for a serine protease priming SARS-Cov-2 for cell entry, and ADAM17, coding for a protease implicated in ACE2 membrane shedding. In contrast, the expression levels of TMPRSS4, coding for a protease that primes SARS-CoV-2 for cell entry similarly to TMPRSS2, were elevated in bronchial epithelial cells from current smokers compared with never smokers, suggesting that higher bronchial TMPRSS4 levels in smokers might put them at higher SARS-Cov-2 infection risk. The effects of smoking on COVID-19 severity need clarification with larger studies. Additionally, the postulated protective effects of nicotine and nitric oxide, which may presumably reduce the risk of a "cytokine storm" in infected individuals, deserve assessment by controlled clinical trials.

Novel Potential Biomarkers Associated With Epithelial to Mesenchymal Transition and Bladder Cancer Prognosis Identified by Integrated Bioinformatic Analysis.

Bladder cancer (BC) is one of the most common malignancies in terms of incidence and recurrence worldwide. The aim of this study was to identify novel prognostic biomarkers related to BC progression utilizing weighted gene co-expression network analysis (WGCNA) and further bioinformatic analysis. First, we constructed a co-expression network by using WGCNA among 274 TCGA-BLCA patients and preliminarily screened out four genes (CORO1C, TMPRSS4, PIK3C2B, and ZNF692) associated with advanced clinical traits. In support, GSE19915 and specimens from 124 patients were used to validate the genes selected by WGCNA; then, CORO1C and TMPRSS4 were confirmed as hub genes with strong prognostic values in BC. Moreover, the result of gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) indicated that CORO1C and TMPRSS4 might be involved in the process of epithelial to mesenchymal transition (EMT) reversely. In addition, high expression of CORO1C was found to be significantly correlated with tumor-infiltrating neutrophils (TINs), a negative regulatory component that facilitates tumor distant progression and induces poor clinical outcome. In conclusion, our study first identified CORO1C and TMPRSS4 as vital regulators in the process of tumor progression through influencing EMT and could be developed to effective prognostic and therapeutic targets in future BC treatment.

Transcriptome profiling and protease inhibition experiments identify proteases that activate H3N2 influenza A and influenza B viruses in murine airways.

Cleavage of influenza virus hemagglutinin (HA) by host proteases is essential for virus infectivity. HA of most influenza A and B (IAV/IBV) viruses is cleaved at a monobasic motif by trypsin-like proteases. Previous studies have reported that transmembrane serine protease 2 (TMPRSS2) is essential for activation of H7N9 and H1N1pdm IAV in mice but that H3N2 IAV and IBV activation is independent of TMPRSS2 and carried out by as-yet-undetermined protease(s). Here, to identify additional H3 IAV- and IBV-activating proteases, we used RNA-Seq to investigate the protease repertoire of murine lower airway tissues, primary type II alveolar epithelial cells (AECIIs), and the mouse lung cell line MLE-15. Among 13 candidates identified, TMPRSS4, TMPRSS13, hepsin, and prostasin activated H3 and IBV HA in vitro IBV activation and replication was reduced in AECIIs from Tmprss2/Tmprss4-deficient mice compared with WT or Tmprss2-deficient mice, indicating that murine TMPRSS4 is involved in IBV activation. Multicycle replication of H3N2 IAV and IBV in AECIIs of Tmprss2/Tmprss4-deficient mice varied in sensitivity to protease inhibitors, indicating that different, but overlapping, sets of murine proteases facilitate H3 and IBV HA cleavages. Interestingly, human hepsin and prostasin orthologs did not activate H3, but they did activate IBV HA in vitro Our results indicate that TMPRSS4 is an IBV-activating protease in murine AECIIs and suggest that TMPRSS13, hepsin, and prostasin cleave H3 and IBV HA in mice. They further show that hepsin and prostasin orthologs might contribute to the differences observed in TMPRSS2-independent activation of H3 in murine and human airways.

miR-1258: a novel microRNA that controls TMPRSS4 expression is associated with malignant progression of papillary thyroid carcinoma.

BACKGROUND: MicroRNA-1258 (miR-1258) has been shown to play an anti-cancer role in a variety of cancers, but its relationship with papillary thyroid cancer (PTC) has not been reported. The emphasis of this research was to reveal the biological function of miR-1258 in PTC and its potential mechanisms. MATERIAL AND METHODS: We measured miR-1258 expression in PTC cells and the transfection efficiency of miR-1258 mimic and miR-1258 inhibitor by quantitative real-time PCR (qRT-PCR) assay. Cell Counting Kit-8 assay (CCK8) and Transwell experiments were conducted to examine the influences of altering miR-1258 expression on the viability, migration, and invasion of PTC cells. Bioinformatics prediction and dual-luciferase experiment were performed to verify the target gene of miR-1258. Finally, we carried out a rescue assay to verify whether the regulation of miR-1258 on the biological behaviour of PTC cells needs to be achieved by regulating TMPRSS4. RESULTS: The outcomes revealed that miR-1258 was lowly expressed in PTC cell lines and miR-1258 showed the lowest expression in KTC-1 and the highest expression in B-CPAP among all tested PTC cell lines. Overexpression of miR-1258 inhibited KTC-1 cell viability and ability to migrate and invade, whereas inhibition of miR-1258 in B-CPAP cells has the opposite effect. Furthermore, we affirmed that miR-1258 can directly target TMPRSS4, and miR-1258 can reduce the biological malignant behaviour of PTC cells via regulation of TMPRSS4. CONCLUSION: Taken together, our research raised the possibility that miR-1258 was an anti-oncogene, which exerts its anti-cancer function by targeting TMPRSS4. Hence, it may be possible to treat PTC by targeting the miR-1258/TMPRSS4 axis in the future.