Involvement of urokinase-type plasminogen activator system in cancer: an overview

Revealing molecular mechanisms of early-onset tongue cancer by spatial transcriptomics

Tongue cancer at a young age demonstrates an increase in incidence, aggressiveness, and poor response to therapy. Classic etiological factors for head and neck tumors such as tobacco, alcohol, and human papillomavirus are not related to early-onset tongue cancer. Mechanisms of development and progression of this cancer remain unclear. In this study, we performed spatial whole-transcriptome profiling of tongue cancer in young adults compared with older patients. Nine patients with tongue squamous cell carcinoma (T2-3N0-1M0) were included and divided into two groups: younger (n = 5) and older than 45 years (n = 4). Formalin-fixed paraffin-embedded (FFPE) and fresh frozen (FF) samples of tumor tissue from 4 young and 5 older patients, respectively, were used for spatial transcriptomic profiling using the 10 × Genomics Visium. The findings were validated using SeekGene single cell full-length RNA sequencing (1 young vs 1 older patient) and TCGA data (15 young vs 70 older patients). As a result, we performed the first successful integration of spatial transcriptomics data from FF and FFPE samples and revealed distinctive features of tongue cancer in young adults. Oxidative stress, vascular mimicry, and MAPK and JAK-STAT pathways were enriched in early-onset tongue cancer. Tumor microenvironment demonstrated increased gene signatures corresponding to myeloid-derived suppressor cells, tumor-associated macrophages, and plasma cells. The invasive front was accompanied by vascular mimicry with arrangement of tumor-associated macrophages and aggregations of plasma cells and lymphocytes organized into tertiary lymphoid structures. Taken together, these results indicate that early-onset tongue cancer has distinct transcriptomic features and molecular mechanisms compared to older patients.

Bioinformatic analysis of the molecular targets of curcumin in colorectal cancer

Colorectal cancer (CRC) is a major global health concern, with rising incidence and mortality rates. Conventional treatments often come with significant complications, prompting the exploration of natural compounds like curcumin as potential therapeutic agents. Using bioinformatic tools, this study investigated the role of curcumin in CRC treatment. Significant protein interactions between curcumin and target proteins were identified in the STITCH database. Differentially expressed genes (DEGs) associated with CRC were then analyzed from GEO databases. Comparing curcumin targets and CRC-related DEGs, nine significant common targets were identified: DNMT1, PCNA, CCND1, PLAU, MMP3, SOX9, FOXM1, CXCL2, and SERPINB5. Pathway enrichment analyses revealed that curcumin-targeted pathways were primarily related to p53, IL-17, NF-kappa B, TNF, and cell cycle signaling, all crucial in CRC development and progression. Further analyses using DAID and EnrichR algorithms showed that the curcumin targets exhibited greater specificity to bronchial epithelial cells and colorectal adenocarcinoma than other diseases. Analyses via the DSigDB database indicated that curcumin ranks highly among other drugs targeting the identified CRC-related genes. Docking studies revealed favorable binding interactions between curcumin and the key CRC-related proteins, suggesting potential molecular mechanisms by which curcumin may exert its effects. In summary, this study provides bioinformatic and docking evidence that curcumin may exert beneficial effects on CRC by modulating the expression or activity of multiple CRC-susceptibility genes involved in critical signaling pathways. These findings warrant further experimental validation and support the potential of curcumin as a therapeutic agent for CRC.

Intrinsic Proteolytic Activities from Cancer Cells Are Sufficient to Activate Alkoxyamine Prodrugs and Induce Cell Death

In search of better specificity and lower chances of resistance, protease-activatable alkoxyamine prodrugs to fight cancer have been proposed. These molecules are made of a peptide linked to an alkoxyamine. Proteolysis of the peptide converts the stable prodrug at 37 °C to a metastable alkoxyamine that spontaneously homolyzes into two free radicals: a stable nitroxide and a very reactive alkyl radical. The alkyl radical induces apoptosis in the surrounding cells by inducing random chemical alterations. Here, we show that varying the peptide moiety from succinyl-Ala-Ala-Pro-Val- to PyroGlu-Gly-Arg- or PyroGlu-Gly-Lys- is effective in switching the activating enzyme from elastase to urokinase. Furthermore, these prodrugs induce the death of HT-1080 cells, a cell line that secretes several active proteases in culture. This cytotoxic activity can be suppressed by protease inhibitors and does not affect cell lines devoid of active urokinase. We thus provide examples of alkoxyamine prodrugs that are efficiently activated by the limited intrinsic protease activity and that succeed in the destruction of cancer cell lines and cancer cells from tumor explants.

Hypoxia-inducible factors in postnatal mouse molar dental pulp development: insights into expression patterns, localisation and metabolic pathways

Hypoxia is relevant to several physiological and pathological processes and this also applies for the tooth. The adaptive response to lowering oxygen concentration is mediated by hypoxia-inducible factors (HIFs). Since HIFs were shown to participate in the promotion of angiogenesis, stem cell survival, odontoblast differentiation and dentin formation, they may play a beneficial role in the tooth reparative processes. Although some data were generated in vitro, little is known about the in vivo context of HIFs in tooth development. In order to contribute to this field, the mouse mandibular first molar was used as a model.The expression and in situ localisation of HIFs were examined at postnatal (P) days P0, P7, P14, using RT-PCR and immunostaining. The expression pattern of a broad spectrum of hypoxia-related genes was monitored by customised PCR Arrays. Metabolic aspects were evaluated by determination of the lactate level and mRNA expression of the mitochondrial marker Nd1.The results show constant high mRNA expression of Hif1a, increasing expression of Hif2a, and very low expression of Hif3a during early postnatal molar development. In the examined period the localisation of HIFs in the nuclei of odontoblasts and the subodontoblastic layer identified their presence during odontoblastic differentiation. Additionally, the lower lactate level and higher expression of mitochondrial Nd1 in advanced development points to decreasing glycolysis during differentiation. Postnatal nuclear localisation of HIFs indicates a hypoxic state in specific areas of dental pulp as oxygen demands depend on physiological events such as crown and root dentin mineralization.

PLAU, transcriptionally negatively regulated by GATA6, promotes lung squamous carcinoma cell proliferation and migration

BACKGROUND

Lung squamous cell carcinoma (LUSC) is associated with high mortality and has limited therapeutic treatment options. Plasminogen activator urokinase (PLAU) plays important roles in tumor cell malignancy. However, the oncogenic role of PLAU in the progression of LUSC remains unknown. GATA-binding factor 6 (GATA6), a key regulator of lung development, inhibits LUSC cell proliferation and migration, but the underlying regulatory mechanism remains to be further explored. Moreover, the regulatory effect of GATA6 on PLAU expression has not been reported. The aim of this study was to identify the role of PLAU and the transcriptional inhibition mechanism of GATA6 on PLAU expression in LUSC.

METHODS

To identify the potential target genes regulated by GATA6, differentially expressed genes (DEGs) obtained from GEO datasets analysis and RNA-seq experiment were subjected to Venn analysis and correlation heatmap analysis. The transcriptional regulatory effects of GATA6 on PLAU expression were detected by real-time PCR, immunoblotting, and dual-luciferase reporter assays. The oncogenic effects of PLAU on LUSC cell proliferation and migration were evaluated by EdU incorporation, Matrigel 3D culture and Transwell assays. PLAU expression was detected in tissue microarray of LUSC via immunohistochemistry (IHC) assay. To determine prognostic factors for prognosis of LUSC patients, the clinicopathological characteristics and PLAU expression were subjected to univariate Cox regression analysis.

RESULTS

PLAU overexpression promoted LUSC cell proliferation and migration. PLAU is overexpressed in LUSC tissues compared with normal tissues. Consistently, high PLAU expression, which acts as an independent risk factor, is associated with poor prognosis of LUSC patients. Furthermore, the expression of PLAU is transcriptionally regulated by GATA6.

CONCLUSION

In this work, it was revealed that PLAU is a novel oncogene for LUSC and a new molecular regulatory mechanism of GATA6 in LUSC was unveiled. Targeting the GATA6/PLAU pathway might help in the development of novel therapeutic treatment strategies for LUSC.

The breast cancer coagulome in the tumor microenvironment and its role in prognosis and treatment response to chemotherapy

BACKGROUND

The procoagulant phenotype in cancer is linked to thrombosis, cancer progression, and immune response. A novel treatment that reduces the risk of both thrombosis and cancer progression without excess bleeding risk remains to be identified.

OBJECTIVES

Here, we aimed to broadly investigate the breast tumor coagulome and its relation to prognosis, treatment response to chemotherapy, and the tumor microenvironment.

METHODS

Key coagulation-related genes (n = 35) were studied in a Norwegian cohort with tumor (n = 134) and normal (n = 189) tissue and in the Cancer Genome Atlas (n = 1052) data set. We performed gene set variation analysis in the Norwegian cohort, and in the Cancer Genome Atlas cohort, associations with the tumor microenvironment and prognosis were evaluated. Analyses were performed with cBioPortal, Estimation of Stromal and Immune cells in Malignant Tumors Using Expression Data, Tumor Immune Estimation Resource, the integrated repository portal for tumor-immune system interactions, Tumor Immune Single-cell Hub 2, and the receiver operating characteristic plotter. Six independent breast cancer cohorts were used to study the tumor coagulome and treatment response to chemotherapy.

RESULTS

Twenty-two differentially expressed coagulation-related genes were identified in breast tumors. Several coagulome factors were correlated with tumor microenvironment characteristics and were expressed by nonmalignant cells in the tumor microenvironment. PLAT and F8 were independent predictors of better overall survival and progression-free survival, respectively. F12 and PLAU were predictors of worse progression-free survival. The PROCR-THBD-PLAT signature showed a promising predictive value (area under the curve, 0.75; 95% CI, 0.69-0.81; P = 3.6 × 10-17) for combination chemotherapy with fluorouracil, epirubicin, and cyclophosphamide.

CONCLUSION

The breast tumor coagulome showed potential in prediction of prognosis and chemotherapy response. Cells within the tumor microenvironment are sources of coagulome factors and may serve as therapeutic targets of coagulation factors.

Ligand-Based Design of Selective Peptidomimetic uPA and TMPRSS2 Inhibitors with Arg Bioisosteres

Trypsin-like serine proteases are involved in many important physiological processes like blood coagulation and remodeling of the extracellular matrix. On the other hand, they are also associated with pathological conditions. The urokinase-pwlasminogen activator (uPA), which is involved in tissue remodeling, can increase the metastatic behavior of various cancer types when overexpressed and dysregulated. Another member of this protease class that received attention during the SARS-CoV 2 pandemic is TMPRSS2. It is a transmembrane serine protease, which enables cell entry of the coronavirus by processing its spike protein. A variety of different inhibitors have been published against both proteases. However, the selectivity over other trypsin-like serine proteases remains a major challenge. In the current study, we replaced the arginine moiety at the P1 site of peptidomimetic inhibitors with different bioisosteres. Enzyme inhibition studies revealed that the phenylguanidine moiety in the P1 site led to strong affinity for TMPRSS2, whereas the cyclohexylguanidine derivate potently inhibited uPA. Both inhibitors exhibited high selectivity over other structurally similar and physiologically important proteases.

Proteomic analysis of exosomes secreted during the epithelial-mesenchymal transition and potential biomarkers of mesenchymal high-grade serous ovarian carcinoma

BACKGROUND

The epithelial-mesenchymal transition (EMT) promotes cell signaling and morphology alterations, contributing to cancer progression. Exosomes, extracellular vesicles containing proteins involved in cell-cell communication, have emerged as a potential source of biomarkers for several diseases.

METHODS

Our aim was to assess the proteome content of exosomes secreted after EMT-induction to identify potential biomarkers for ovarian cancer classification. EMT was induced in the ovarian cancer cell line CAOV3 by treating it with EGF (10 ng/mL) for 96 h following 24 h of serum deprivation. Subsequently, exosomes were isolated from the supernatant using selective centrifugation after decellularization, and their characteristics were determined. The proteins present in the exosomes were extracted, identified, and quantified using Label-Free-Quantification (LFQ) via Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). To identify potential biomarkers, the obtained proteomic data was integrated with the TGGA database for mRNA expression using principal component analysis and a conditional inference tree.

RESULTS

The exosomes derived from CAOV3 cells exhibited similar diameter and morphology, measuring approximately 150 nm, regardless of whether they were subjected to EMT stimulation or not. The proteomic analysis of proteins from CAOV3-derived exosomes revealed significant differential regulation of 157 proteins, with 100 showing upregulation and 57 downregulation upon EMT induction. Further comparison of the upregulated proteins with the TCGA transcriptomic data identified PLAU, LAMB1, COL6A1, and TGFB1 as potential biomarkers of the mesenchymal HGSOC subtype.

CONCLUSIONS

The induction of EMT, the isolation of exosomes, and the subsequent proteomic analysis highlight potential biomarkers for an aggressive ovarian cancer subtype. Further investigation into the role of these proteins is warranted to enhance our understanding of ovarian cancer outcomes.

SERPINE1 and SERPINB7 as potential biomarkers for intravenous vitamin C treatment in non-small-cell lung cancer

High dose intravenous vitamin C (IVC) has been proposed as a pro-oxidant anticancer agent. However, there is a lack of biomarkers that are specific for this treatment. Here, we explored profiles of gene expression responding to IVC treatment in non-small cell lung cancer (NSCLC) cells as an effort for potential biomarker discovery. Genome-wide RNA-seq was performed in human NSCLC cell lines treated with pharmacological concentrations of vitamin C(VitC) for differential expression of genes. The identified genes were analyzed for correlations with patient prognosis using data from the Kaplan-Meier Plotter and the Human Protein Atlas databases. Further, tumor samples from a retrospective study of 153 NSCLC patients were analyzed with immunohistochemistry for expression of targeted genes, and patient prognosis was correlated to these genes. Two genes, namely SERPINE1 and SERPINB7 were found to be downregulated in NSCLC cells following VitC treatment. Combined patient data from the cohort analysis and online databases revealed that these 2 genes presented an unfavorable prognostic prediction of overall survival (OS) in NSCLC patients receiving standard of care. However, high expression level of these 2 genes were associated with prolonged OS in NSCLC patients receiving IVC in addition to standard of care. These data revealed that SERPINE1 and SERPINB7 have the potential to serve as predictive factors indicating favorable responses to IVC treatment in patients with NSCLC. Further validations are warranted.

circPSD3 is a promising inhibitor of uPA system to inhibit vascular invasion and metastasis in hepatocellular carcinoma

BACKGROUND

Vascular invasion is a major route for intrahepatic and distant metastasis in hepatocellular carcinoma (HCC) and is a strong negative prognostic factor. Circular RNAs (circRNAs) play important roles in tumorigenesis and metastasis. However, the regulatory functions and underlying mechanisms of circRNAs in the development of vascular invasion in HCC are largely unknown.

METHODS

High throughput sequencing was used to screen dysregulated circRNAs in portal vein tumor thrombosis (PVTT) tissues. The biological functions of candidate circRNAs in the migration, vascular invasion, and metastasis of HCC cells were examined in vitro and in vivo. To explore the underlying mechanisms, RNA sequencing, MS2-tagged RNA affinity purification, mass spectrometry, and RNA immunoprecipitation assays were performed.

RESULTS

circRNA sequencing followed by quantitative real-time PCR (qRT-PCR) revealed that circRNA pleckstrin and Sect. 7 domain containing 3 (circPSD3) was significantly downregulated in PVTT tissues. Decreased circPSD3 expression in HCC tissues was associated with unfavourable characteristics and predicted poor prognosis in HCC. TAR DNA-binding protein 43 (TDP43) inhibited the biogenesis of circPSD3 by interacting with the downstream intron of pre-PSD3. circPSD3 inhibited the intrahepatic vascular invasion and metastasis of HCC cells in vitro and in vivo. Serpin family B member 2 (SERPINB2), an endogenous bona fide inhibitor of the urokinase-type plasminogen activator (uPA) system, is the downstream target of circPSD3. Mechanistically, circPSD3 interacts with histone deacetylase 1 (HDAC1) to sequester it in the cytoplasm, attenuating the inhibitory effect of HDAC1 on the transcription of SERPINB2. In vitro and in vivo studies demonstrated that circPSD3 is a promising inhibitor of the uPA system.

CONCLUSIONS

circPSD3 is an essential regulator of vascular invasion and metastasis in HCC and may serve as a prognostic biomarker and therapeutic target.

Role of cancer-associated fibroblasts in the progression, therapeutic resistance and targeted therapy of oesophageal squamous cell carcinoma

Oesophageal squamous cell carcinoma (ESCC) is one of the most aggressive malignant tumours with high morbidity and mortality. Although surgery, radiotherapy and chemotherapy are common treatment options available for oesophageal cancer, the 5-year survival rate remains low after treatment. On the one hand, many oesophageal cancers are are discovered at an advanced stage and, on the other hand, treatment resistance is a major obstacle to treating locally advanced ESCC. Cancer-associated fibroblasts (CAFs), the main type of stromal cell in the tumour microenvironment, enhance tumour progression and treatment resistance and have emerged as a major focus of study on targeted therapy of oesophageal cancer.With the aim of providing potential, prospective targets for improving therapeutic efficacy, this review summarises the origin and activation of CAFs and their specific role in regulating tumour progression and treatment resistance in ESCC. We also emphasize the clinical potential and emerging trends of ESCC CAFs-targeted treatments.

CD44s-activated tPA/LRP1-NFκB pathway drives lamellipodia outgrowth in luminal-type breast cancer cells

Some cancer cells migration and metastasis are characterized by the outgrowth of lamellipodia protrusions in which the underlying mechanism remains unclear. Evidence has confirmed that lamellipodia formation could be regulated by various adhesion molecules, such as CD44, and we previously reported that lamellipodia at the leading edge of luminal type breast cancer (BrCa) were enriched with high expression of CD44. In this study, we found that the overexpression of CD44s could promote lamellipodia formation in BrCa cells through inducing tissue type plasminogen activator (tPA) upregulation, which was achieved by PI3K/Akt signaling pathway activation. Moreover, we revealed that tPA could interact with LDL receptor related protein 1 (LRP1) to activate the downstream NFκB signaling pathway, which in turn facilitate lamellipodia formation. Notably, inhibition of the tPA/LRP1-NFkB signaling cascade could attenuate the CD44s-induced lamellipodia formation. Thus, our findings uncover a novel role of CD44s in driving lamellipodia outgrowth through tPA/LRP1-NFkB axis in luminal BrCa cells that may be helpful for seeking potential therapeutic targets.

Good or bad: Paradox of plasminogen activator inhibitor 1 (PAI-1) in digestive system tumors

The fibrinolytic system is involved in many physiological functions, among which the important members can interact with each other, either synergistically or antagonistically to participate in the pathogenesis of many diseases. Plasminogen activator inhibitor 1 (PAI-1) acts as a crucial element of the fibrinolytic system and functions in an anti-fibrinolytic manner in the normal coagulation process. It inhibits plasminogen activator, and affects the relationship between cells and extracellular matrix. PAI-1 not only involved in blood diseases, inflammation, obesity and metabolic syndrome but also in tumor pathology. Especially PAI-1 plays a different role in different digestive tumors as an oncogene or cancer suppressor, even a dual role for the same cancer. We term this phenomenon "PAI-1 paradox". PAI-1 is acknowledged to have both uPA-dependent and -independent effects, and its different actions can result in both beneficial and adverse consequences. Therefore, this review will elaborate on PAI-1 structure, the dual value of PAI-1 in different digestive system tumors, gene polymorphisms, the uPA-dependent and -independent mechanisms of regulatory networks, and the drugs targeted by PAI-1 to deepen the comprehensive understanding of PAI-1 in digestive system tumors.

uPA deficiency aggravates cBSA-induced membranous nephropathy through Th2-prone immune response in mice

Urokinase plasminogen activator (uPA) is a crucial activator of the fibrinolytic system that modulates tissue remodeling, cancer progression, and inflammation. However, its role in membranous nephropathy (MN) remains unclear. To clarify this issue, an established mouse model mimicking human MN induced by cationic bovine serum albumin (cBSA) in BALB/c mice was used, which have a Th2-prone genetic background. To induce MN, cBSA was injected into Plau knockout (Plau-/-) and wild-type (WT) mice. The blood and urine samples were collected to measure biochemical parameters, including serum concentrations of IgG1 and IgG2a, using enzyme-linked immunoassay. The kidneys were histologically examined for the presence of glomerular polyanions, reactive oxygen species (ROS), and apoptosis, and transmission electron microscopy was used to examine subepithelial deposits. Lymphocyte subsets were determined by flow cytometry. Four weeks post-cBSA administration, Plau-/- mice exhibited a significantly high urine protein/creatine ratio, hypoalbuminemia, and hypercholesterolemia compared with WT mice. Histologically, compared with WT mice, Plau-/- mice showed more severe glomerular basement thickening, mesangial expansion, IgG granular deposition, intensified podocyte effacement, irregular thickening of glomerular basement membrane and subepithelial deposits, and abolishment of the glycocalyx. Moreover, increased renal ROS and apoptosis were observed in Plau-/- mice with MN. B lymphocyte subsets and the IgG1/IgG2a ratio were significantly higher in Plau-/- mice after MN induction. Thus, uPA deficiency induces a Th2-dominant immune response, leading to increased subepithelial deposits, ROS, and apoptosis in the kidneys, subsequently exacerbating MN progression in mice. This study provides a novel insight into the role of uPA in MN progression.

Label-Free Determination of the Kinetic Parameters of Protein-Aptamer Interaction by Surface Plasmon Resonance

Due to their high specificity and affinity to target molecules, aptamers can be used as powerful tools in diagnostics, therapeutics, and environmental or food analytics. For the use in various applications, the detailed characterization of their binding behavior is an important step after selection to determine the interaction strength between the aptamer and its target and to find the best kinetics depending on the field of application. The surface plasmon resonance (SPR) spectroscopy is a powerful technology to investigate important parameters in molecular interaction, for example, kinetics, affinity, and specificity. The most-used system is the Biacore™ SPR system which comprises an optical biosensor for label-free monitoring of binding events in real time based on SPR. This biophysical phenomenon describes the changes in refractive index on a sensor surface which can be used to measure binding events and to determine kinetic constants. In this chapter, a detailed protocol for the determination of kinetic constants for protein-aptamer interaction is provided. An 82-nt long ssDNA aptamer which are targeted against human urokinase is used as a model system for determination of binding and dissociation constants using Biacore™ SPR technology. A detailed note section provides useful tips and pitfalls at the end of this chapter.

Urokinase-type plasminogen activator receptor (uPAR) assessed by liquid biopsies and PET/CT for prognostication in head and neck cancer patients

Strong prognostic biomarkers are lacking regarding the stratification of treatment and surveillance regimens in head and neck squamous cell carcinoma (HNSCC). The study aimed to assess the prognostic value of soluble urokinase-type plasminogen activator receptor in plasma (suPAR) compared to evaluation by uPAR-positron-emission-tomography (PET) in HNSCC patients. Plasma from 19 controls and 49 HNSCC patients referred to curatively intended radiotherapy (2017-2021) was collected pre-treatment and post-treatment (n = 37). Information on uPAR-PET was available from previous evaluation. Patient median suPAR was significantly higher pre- and post-treatment compared to controls (p = 0.013, p = 0.003) and increased significantly during radiotherapy (p = 0.003). Pre-treatment suPAR did not predict survival outcomes. Post-treatment suPAR significantly predicted RFS (HR = 6.67 (95% CI 1.44-30.9) p = 0.015), but not OS (HR = 3.29 (95% CI 0.882-12.3) p = 0.076) in univariate analysis. RFS prediction was maintained for post-treatment suPAR in multivariate analysis, including TNM-stage (HR = 6.62 (95% CI 1.40-31.4) p = 0.017). Pre-treatment uPAR-PET/CT and post-treatment suPAR was available in 24 patients. High uPAR-estimates on both modalities was significantly associated with poor RFS compared to patients with low uPAR-estimates (log-rank, p = 0.008). Patients with discordant uPAR-estimates (one-low/one-high) were at intermediate risk, although non-significant (p = 0.131). In conclusion, pre-treatment suPAR did not predict RFS or OS. Pre-treatment uPAR-PET and post-treatment suPAR predicted RFS.

Chronic inflammation, cancer development and immunotherapy

Chronic inflammation plays a pivotal role in cancer development. Cancer cells interact with adjacent cellular components (pro-inflammatory cells, intrinsic immune cells, stromal cells, etc.) and non-cellular components to form the inflammatory tumor microenvironment (TME). Interleukin 6 (IL-6), macrophage migration inhibitory factor (MIF), immune checkpoint factors and other pro-inflammatory cytokines produced by intrinsic immune cells in TME are the main mediators of intercellular communication in TME, which link chronic inflammation to cancer by stimulating different oncogenic signaling pathways and improving immune escape to promote cancer development. In parallel, the ability of monocytes, T regulatory cells (Tregs) and B regulatory cells (Bregs) to perform homeostatic tolerogenic functions is hijacked by cancer cells, leading to local or systemic immunosuppression. Standard treatments for advanced malignancies such as chemotherapy and radiotherapy have improved in the last decades. However, clinical outcomes of certain malignant cancers are not satisfactory due to drug resistance and side effects. The clinical application of immune checkpoint therapy (ICT) has brought hope to cancer treatment, although therapeutic efficacy are still limited due to the immunosuppressive microenvironment. Emerging evidences reveal that ideal therapies including clearance of tumor cells, disruption of tumor-induced immunosuppression by targeting suppressive TME as well as reactivation of anti-tumor T cells by ICT. Here, we review the impacts of the major pro-inflammatory cells, mediators and their downstream signaling molecules in TME on cancer development. We also discuss the application of targeting important components in the TME in the clinical management of cancer.

Prognostic Value of Urokinase-Type Plasminogen Activator Receptor PET/CT in Head and Neck Squamous Cell Carcinomas and Comparison with 18F-FDG PET/CT: A Single-Center Prospective Study

The aim of this phase II clinical trial (NCT02965001) was to evaluate the prognostic value of urokinase-type plasminogen activator receptor (uPAR) PET/CT with the novel ligand ⁶⁸Ga-NOTA-AE105 in head and neck cancer and compare it with ¹⁸F-FDG. Methods: Patients with head and neck squamous cell carcinoma referred for curatively intended radiotherapy were eligible and prospectively included in this study. ⁶⁸Ga-uPAR and ¹⁸F-FDG PET/CT were performed before initiation of curatively intended radiotherapy, and the SUV_max of the primary tumor was measured on both PET/CT studies by 2 independent readers. Relapse-free survival (RFS) and overall survival (OS) were calculated, and optimal cutoffs were established for ⁶⁸Ga-uPAR and ¹⁸F-FDG PET independently and compared using log rank and Kaplan-Meier statistics, as well as univariate and multivariate analysis in a Cox proportional-hazards model. Results: In total, 57 patients were included and followed for a median of 33.8 mo (range, 2.30-47.2, mo). The median SUV_max of the primary tumors was 2.98 (range, 1.94-5.24) for ⁶⁸Ga-uPAR and 15.7 (range, 4.24-45.5) for ¹⁸F-FDG. The optimal cutoffs for ⁶⁸Ga-NOTA-AE105 SUV_max in the primary tumor were 2.63 for RFS and 2.66 for OS. A high uptake of ⁶⁸Ga-NOTA-AE105 (SUV_max above cutoff) was significantly associated with poor RFS and OS (log-rank P = 0.012 and P = 0.022). ⁶⁸Ga-NOTA-AE105 uptake in the primary tumor was significantly associated with poor RFS in univariate analysis (hazard ratio [HR], 8.53 [95% CI, 1.12-64.7]; P = 0.038), and borderline-associated with OS (HR, 7.44 [95% CI, 0.98-56.4]; P = 0.052). For ¹⁸F-FDG PET, the optimal cutoffs were 22.7 for RFS and 22.9 for OS. An ¹⁸F-FDG SUV_max above the cutoff was significantly associated with reduced RFS (log-rank P = 0.012) and OS (log-rank P = 0.000). ¹⁸F-FDG uptake was significantly associated with reduced RFS (HR, 3.27 [95% CI, 1.237-8.66]; P = 0.017) and OS (HR, 7.10 [95% CI, 2.60-19.4]; P < 0.001) in univariate analysis. In a multivariate analysis including ⁶⁸Ga-uPAR SUV_max, ¹⁸F-FDG SUV_max, TNM stage, and p16 status, only ⁶⁸Ga-uPAR SUV_max remained significant (HR, 8.51 [95% CI, 1.08-66.9]; P = 0.042) for RFS. For OS, only TNM stage and ¹⁸F-FDG remained significant. Conclusion: The current trial showed promising results for the use of ⁶⁸Ga-uPAR PET SUV_max in the primary tumor to predict RFS in head and neck squamous cell carcinoma patients referred for curatively intended radiotherapy when compared with ¹⁸F-FDG PET, TNM stage, and p16 status. ⁶⁸Ga-uPAR PET could potentially become valuable for identification of patients suited for deescalation of treatment and risk-stratified follow-up schemes.

Bicyclic peptide-based assay for uPA cancer biomarker

The use of synthetic bioreceptors to develop biosensing platforms has been recently gaining momentum. This case study compares the performance of a biosensing platform for the human biomarker urokinase-type plasminogen activator (h-uPA) when using two bicyclic peptides (P₁ and P₂) with different affinities for the target protein. The bioreceptors P₁ and P₂ were immobilized on magnetic microbeads and tested within a sandwich-type affinity electrochemical assay. Apart from enabling h-uPA quantification at nanomolar levels (105.8 ng/mL for P₁ and 32.5 ng/mL for P₂), this case study showed the potential of synthetic bicyclic peptides applicability and how bioreceptor affinity can influence the performance of the final sensing platform.

Immunohistochemical study of the plasminogen activator system in benign epithelial odontogenic lesions

The aim of this study was to analyze and compare the immunohistochemical expression of plasminogen activator system (PAS) proteins (uPA, uPAR, and PAI-1) in ameloblastomas (AMBs), odontogenic keratocysts (OKCs), and dental follicles (DFs) representing normal odontogenic tissue, as well as to investigate possible correlations between these proteins. Twenty AMBs, 20 OKCs, and 10 DFs were selected for immunohistochemical analysis. In each case, the immunoexpression of uPA, uPAR, and PAI-1 was evaluated semiquantitatively based on the percentage of positivity in odontogenic epithelial and connective tissue cells. The epithelial immunoexpression of uPA was significantly lower in AMBs when compared to OKCs (p = 0.001) and DFs (p = 0.029). Significantly higher epithelial immunostaining for uPAR was observed in AMBs when compared to OKCs (p < 0.001). There were no significant differences in the epithelial immunoexpression of PAI-1 between AMBs and OKCs (p = 1.000). The correlations found for the expression of the studied proteins were not statistically significant (p > 0.05). However, the epithelial and connective tissue expressions of uPAR have a strong positive and statistically significant correlation in AMBs. The present results suggest that uPA is involved in the pathogenesis of OKCs and that uPAR may participate in tumorigenesis in AMBs. The high percentage of PAI-1-positive cells suggests a possible role for this protein in the development of AMBs and OKCs. Furthermore, the studied proteins do not seem to act synergistically in AMBs, OKCs, and DFs.

Inhibition of Human Urokinase-Type Plasminogen Activator (uPA) Enzyme Activity and Receptor Binding by DNA Aptamers as Potential Therapeutics through Binding to the Different Forms of uPA

Urokinase-type plasminogen activator is widely discussed as a marker for cancer prognosis and diagnosis and as a target for cancer therapies. Together with its receptor, uPA plays an important role in tumorigenesis, tumor progression and metastasis. In the present study, systematic evolution of ligands by exponential enrichment (SELEX) was used to select single-stranded DNA aptamers targeting different forms of human uPA. Selected aptamers allowed the distinction between HMW-uPA and LMW-uPA, and therefore, presumably, have different binding regions. Here, uPAapt-02-FR showed highly affine binding with a K_D of 0.7 nM for HMW-uPA and 21 nM for LMW-uPA and was also able to bind to pro-uPA with a K_D of 14 nM. Furthermore, no cross-reactivity to mouse uPA or tissue-type plasminogen activator (tPA) was measured, demonstrating high specificity. Suppression of the catalytic activity of uPA and inhibition of uPAR-binding could be demonstrated through binding with different aptamers and several of their truncated variants. Since RNA aptamers are already known to inhibit uPA-uPAR binding and other pathological functions of the uPA system, these aptamers represent a novel, promising tool not only for detection of uPA but also for interfering with the pathological functions of the uPA system by additionally inhibiting uPA activity.

Anticancer Effects with Molecular Docking Confirmation of Newly Synthesized Isatin Sulfonamide Molecular Hybrid Derivatives against Hepatic Cancer Cell Lines

The current study investigated the cytotoxic effect of ten sulfonamide-derived isatins, following molecular hybridization, based on the association principles, on hepatocellular carcinoma (HCC) HepG2 and Huh7 cell lines, compared for safety using human normal retina pigmented epithelial (RPE-1) cells. The ten compounds showed variable in vitro cytotoxicity on HepG2 and Huh7 cells, using the MTT assay. Four compounds (4/10) were highly cytotoxic to both HepG2 and HuH7. However, only 3 of these 4 were of the highest safety margin on RPE-1 cells in vitro and in the in vivo acute (14-day) oral toxicity study. These later, superior three compounds' structures are 3-hydroxy-3-(2-oxo-2-(p-tolyl)ethyl)-5-(piperidin-1-ylsulfonyl)indolin-2-one (3a), N-(4-(2-(2-oxo-5-(piperidin-1-ylsulfonyl)indolin-3-ylidene)acetyl)phenyl)acetamide (4b), and N-(3-(2-(2-oxo-5-(piperidin-1-ylsulfonyl)indolin-3-ylidene)acetyl)phenyl)acetamide (4c). The half-maximal inhibitory concentration (IC50) of the tested compounds (3a, 4b, and 4c) on HepG2 cells were approximately 16.8, 44.7, and 39.7 μM, respectively. The 3a, 4b, and 4c compounds significantly decreased the angiogenic marker epithelial growth factor receptor (EGFR) level and that was further confirmed via molecular docking inside the EFGR active site (PDB: 1M17). The binding free energies ranged between -19.21 and -21.74 Kcal/mol compared to Erlotinib (-25.65 Kcal/mol). The most promising compounds, 3a, 4b, and 4c, showed variable anticancer potential on "hallmarks of cancer", significant cytotoxicity, and apoptotic anti-angiogenic and anti-invasive effects, manifested as suppression of Bcl-2, urokinase plasminogen activation, and heparanase expression in HepG2-treated cells' lysate, compared to non-treated HepG2 cells. In conclusion, compound "3a" is highly comparable to doxorubicin regarding cell cycle arrest at G2/M, the pre-G0 phases and early and late apoptosis induction and is comparable to Erlotinib regarding binding to EGFR active site. Therefore, the current study could suggest that compound "3a" is, hopefully, the most safe and active synthesized isatin sulfonamide derivative for HCC management.

Disruption of Water Networks is the Cause of Human/Mouse Species Selectivity in Urokinase Plasminogen Activator (uPA) Inhibitors Derived from Hexamethylene Amiloride (HMA)

The urokinase plasminogen activator (uPA) plays a critical role in tumor cell invasion and migration and is a promising antimetastasis target. 6-Substituted analogues of 5-N,N-(hexamethylene)amiloride (HMA) are potent and selective uPA inhibitors that lack the diuretic and antikaliuretic properties of the parent drug amiloride. However, the compounds display pronounced selectivity for human over mouse uPA, thus confounding interpretation of data from human xenograft mouse models of cancer. Here, computational and experimental findings reveal that residue 99 is a key contributor to the observed species selectivity, whereby enthalpically unfavorable expulsion of a water molecule by the 5-N,N-hexamethylene ring occurs when residue 99 is Tyr (as in mouse uPA). Analogue 7 lacking the 5-N,N-hexamethylene ring maintained similar water networks when bound to human and mouse uPA and displayed reduced selectivity, thus supporting this conclusion. The study will guide further optimization of dual-potent human/mouse uPA inhibitors from the amiloride class as antimetastasis drugs.

Structure-based molecular insights into matrix metalloproteinase inhibitors in cancer treatments

Protease inhibitors are of considerable interest as anticancer agents. Matrix metalloproteinases (MMPs) were the earliest type of proteases considered as anticancer targets. The developments of MMP inhibitors (MMPIs) by pharmaceutical companies can be dated from the early 1980s. Thus far, none of the over 50 MMPIs entering clinical trials have been approved. This work summarizes the reported studies on the structure of MMPs and complexes with ligands and inhibitors, based on which, the authors analyzed the clinical failures of MMPIs in a structural biological manner. Furthermore, MMPs were systematically compared with urokinase, a protease-generating plasmin, which plays similar pathological roles in cancer development; the reasons for the clinical successes of urokinase inhibitors and the clinical failures of MMPIs are discussed.

uPAR: An Essential Factor for Tumor Development

Tumorigenesis is closely related to the loss of control of many genes. Urokinase-type plasminogen activator receptor (uPAR), a glycolipid-anchored protein on the cell surface, is controlled by many factors in tumorigenesis and is expressed in many tumor tissues. In this review, we summarize the regulatory effects of the uPAR signaling pathway on processes and factors related to tumor progression, such as tumor cell proliferation, adhesion, metastasis, glycolysis, tumor microenvironment and angiogenesis. Overall, the evidence accumulated to date suggests that uPAR induction by tumor progression may be one of the most important factors affecting therapeutic efficacy. An improved understanding of the interactions between uPAR and its coreceptors in cancer will provide critical biomolecular information that may help to better predict the disease course and response to therapy.

5-Azacitidine and Trichostatin A induce DNA damage and apoptotic responses in tongue squamous cell carcinoma: An in vitro study

OBJECTIVE

The present in vitro study aims to investigate the potential use of epigenetic inhibitors as treatment modalities in tongue squamous cell carcinoma.

DESIGN

The human tongue squamous cell carcinoma cell line (CAL-27) was cultured and exposed to varying concentrations of 5-Azacitidine (5-Aza) or Trichostatin A (TSA) in the culture medium. The cell apoptosis was evaluated using Annexin V/PI by flow cytometry. To evaluate DNA damage response, γH2AX foci analysis was performed using immunofluorescence. Single cell gel electrophoresis (SCGE) was applied to measure DNA strand breaks. Gene expression was assessed by quantitative real-time PCR.

RESULTS

The results showed that 5-Aza and TSA had apoptotic effects on the SCC cell line at concentrations of 50-200 µM and 0.5-5 µM, respectively. Immunofluorescence analysis showed increased expression of γH2AX, the marker of DNA damage response after treatment of 5-Aza and TSA that was associated with increased DNA strand breaks. The expressions of urokinase plasminogen activator, its receptor and matrix metalloproteinase-2, were significantly reduced in TSA- and 5-Aza-treated cells.

CONCLUSIONS

Our results showed that 5-Aza and TSA increase apoptotic and DNA damage response in squamous cell carcinoma cell line while reducing the expression of tumor invasion genes that further indicating the potential therapeutic value of two epigenetic modifiers in squamous cell carcinoma.

Urokinase plasminogen activator predicts poor prognosis in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and its prognosis remains dismal. Hence, it is important to identify the diagnostic and prognostic biomarkers for HCC. Urokinase plasminogen activator (uPA), an extracellular matrix (ECM)-degrading protease, plays a pivotal role in the invasion and metastasis of HCC.

Methods

To confirm the clinical significance of uPA in HCC, we explored uPA expression in HCC in The Cancer Genome Atlas (TCGA) database. The expression level of uPA was further verified by quantitative reverse transcription polymerized chain reaction (qRT-PCR) in 133 pairs of primary HCC samples. A survival analysis was conducted with the Kaplan-Meier method in the HCC samples and TCGA database.

Results

Our results showed that uPA was overexpressed in HCC and was significantly associated with HCC tumor size (P=0.015), differentiation grade (P=0.028), and absence of tumor encapsulation (P=0.010). Patients with high uPA expression levels had a poor outcome (P=0.026). TCGA database analysis was also consistent with our experimental results.

Conclusions

In conclusion, our findings revealed that uPA was overexpressed in HCC and was related to HCC malignant features including tumor size, differentiation grade and absence of tumor encapsulation. High uPA expression had a shorter survival time. It is a potential prognostic biomarker of HCC.

Dihydromyricetin suppresses cell metastasis in human osteosarcoma through SP-1- and NF-κB-modulated urokinase plasminogen activator inhibition

BACKGROUND

Metastasis caused a decline in the 5-years survival rate of osteosarcoma. Therefore, developing new targeted therapeutics for osteosarcoma treatment is imperative. Dihydromyricetin (DHM) has several physiological functions: it counteracts inflammation, oxidation, and antitumor properties. However, the effects of DHM on osteosarcoma and its underlying mechanisms are still not well understood.

PURPOSE

In this study, we investigated the antimetastatic properties of DHM in human osteosarcoma U-2 OS and HOS cells.

METHODS

The effects of DHM (0, 25, 50, 75, and 100 μM) on cell viability, migration, and invasion were examined. Western blotting, RT-PCR, and quantitative real-time PCR (QPCR) were determined urokinase plasminogen activator (uPA) expression. The expression of transcriptional factor SP-1 and NF-κB was determined by using immunofluorescence assay, chromatin immunoprecipitation assay, and site-directed mutagenesis luciferase reporter.

RESULTS

We observed that DHM suppresses cell migration and invasion in osteosarcoma cell lines. In addition, DHM inhibits metastasis by downregulating urokinase plasminogen activator (uPA) expression. Moreover, real-time polymerase chain reaction and promoter activity assays revealed that DHM decreased uPA expression at transcription levels. Furthermore, the inhibition of uPA expression was associated with the suppression of SP-1 and NF-κB, which bind to the uPA promoter. Regardless of blocking or inducing the extracellular signal-regulated kinase (ERK) pathway, we verified that the DHM-related suppression of uPA and cell metastasis occurred through the p-ERK pathway.

CONCLUSION

We are the first study to propose that DHM suppresses osteosarcoma metastasis through the ERK pathway and through the suppression of SP-1 and NF-κB to inhibit downstream uPA expression. DHM is a potential therapeutic agent for antimetastatic therapy against osteosarcoma.

Development of AE147 Peptide-Conjugated Nanocarriers for Targeting uPAR-Overexpressing Cancer Cells

Purpose

An AE147 peptide-conjugated nanocarrier based on PEGylated liposomes was developed in order to target the metastatic tumors overexpressing urokinase-type plasminogen activator receptor (uPAR), which cancer progression via uPA signaling. Therefore, the AE147 peptide-conjugated nanocarrier system may hold the potential for active targeting of metastatic tumors.

Methods

The AE147 peptide, an antagonist of uPAR, was conjugated to the PEGylated liposomes for targeting metastatic tumors overexpressing uPAR. Docetaxel (DTX), an anticancer drug, was incorporated into the nanocarriers. The structure of the AE147-conjugated nanocarrier, its physicochemical properties, and in vivo biodistribution were evaluated.

Results

The DTX-loaded nanocarrier showed a spherical structure, a high drug-loading capacity, and a high colloidal stability. Drug carrying AE147 conjugates were actively taken up by the uPAR-overexpressing MDA-MB-231 cancer cells. In vivo animal imaging confirmed that the AE147-conjugated nanoparticles effectively accumulated at the sites of tumor metastasis.

Conclusion

The AE147-nanocarrier showed potential for targeting metastatic tumor cells overexpressing uPAR and as a nanomedicine platform for theragnosis applications. These results suggest that this novel nano-platform will facilitate further advancements in cancer therapy.

Proteases Regulate Cancer Stem Cell Properties and Remodel Their Microenvironment

Proteolytic activity is perturbed in tumors and their microenvironment, and proteases also affect cancer stem cells (CSCs). CSCs are the therapy-resistant subpopulation of cancer cells with tumor-initiating capacity that reside in specialized tumor microenvironment niches. In this review, we briefly summarize the significance of proteases in regulating CSC activities with a focus on brain tumor glioblastoma. A plethora of proteases and their inhibitors participate in CSC invasiveness and affect intercellular interactions, enhancing CSC immune, irradiation, and chemotherapy resilience. Apart from their role in degrading the extracellular matrix enabling CSC migration in and out of their niches, we review the ability of proteases to modulate CSC properties, which prevents their elimination. When designing protease-oriented therapies, the multifaceted roles of proteases should be thoroughly investigated.

PLAU Promotes Cell Proliferation and Epithelial-Mesenchymal Transition in Head and Neck Squamous Cell Carcinoma

Plasminogen activator, urokinase (uPA) is a secreted serine protease whose Dysregulation is often accompanied by various cancers. However, the biological functions and potential mechanisms of PLAU in head and neck squamous cell carcinoma (HNSCC) remain undetermined. Here, the expression, prognosis, function, and coexpression genetic networks of PLAU in HNSCC were investigated by a series of public bioinformatics tools. A Higher PLAU level predicted a poorer clinical outcome. Meanwhile, functional network analysis implied that PLAU and associated genes mainly regulated cell-substrate adhesion, tissue migration, and extracellular matrix binding. The top 4 significantly associated genes are C10orf55, ITGA5, SERPINE1, and TNFRSF12A. Pathway enrichment analysis indicated that PLAU might activate the epithelial-to-mesenchymal transition (EMT) process, which could explain the poor prognosis in HNSCC. Besides, genes associated with PLAU were also enriched in EMT pathways. We further validated the bioinformatics analysis results by in vivo and in vitro experiments. Then, we found that much more PLAU was detected in HNSCC tissues, and the silencing of PLAU inhibit the proliferation, migration, and EMT process of CAL27 cell lines. Notably, the downregulation of PLAU decreased the expression of TNFRSF12A. Moreover, knockdown TNFRSF12A also inhibits cell proliferation and migration. In vivo experiment results indicated that PLAU inhibition could suppress tumor growth. Collectively, PLAU is necessary for tumor progression and can be a diagnostic and prognostic biomarker in HNSCC.

MicroRNAs and angiogenesis: a new era for the management of colorectal cancer

MicroRNAs (miRNAs) are a class of small noncoding RNA molecules containing only 20–22 nucleotides. MiRNAs play a role in gene silencing and translation suppression by targeting and binding to mRNA. Proper control of miRNA expression is very important for maintaining a normal physiological environment because miRNAs can affect most cellular pathways, including cell cycle checkpoint, cell proliferation, and apoptosis pathways, and have a wide range of target genes. With these properties, miRNAs can modulate multiple signalling pathways involved in cancer development, such as cell proliferation, apoptosis, and migration pathways. MiRNAs that activate or inhibit the molecular pathway related to tumour angiogenesis are common topics of research. Angiogenesis promotes tumorigenesis and metastasis by providing oxygen and diffusible nutrients and releasing proangiogenic factors and is one of the hallmarks of tumour progression. CRC is one of the most common tumours, and metastasis has always been a difficult issue in its treatment. Although comprehensive treatments, such as surgery, radiotherapy, chemotherapy, and targeted therapy, have prolonged the survival of CRC patients, the overall response is not optimistic. Therefore, there is an urgent need to find new therapeutic targets to improve CRC treatment. In a series of recent reports, miRNAs have been shown to bidirectionally regulate angiogenesis in colorectal cancer. Many miRNAs can directly act on VEGF or inhibit angiogenesis through other pathways (HIF-1a, PI3K/AKT, etc.), while some miRNAs, specifically many exosomal miRNAs, are capable of promoting CRC angiogenesis. Understanding the mechanism of action of miRNAs in angiogenesis is of great significance for finding new targets for the treatment of tumour angiogenesis. Deciphering the exact role of specific miRNAs in angiogenesis is a challenge due to the high complexity of their actions. Here, we describe the latest advances in the understanding of miRNAs and their corresponding targets that play a role in CRC angiogenesis and discuss possible miRNA-based therapeutic strategies.

Moscatilin Inhibits Metastatic Behavior of Human Hepatocellular Carcinoma Cells: A Crucial Role of uPA Suppression via Akt/NF-κB-Dependent Pathway

Hepatocellular carcinoma (HCC) frequently shows early invasion into blood vessels as well as intrahepatic metastasis. Innovations of novel small-molecule agents to block HCC invasion and subsequent metastasis are urgently needed. Moscatilin is a bibenzyl derivative extracted from the stems of a traditional Chinese medicine, orchid Dendrobium loddigesii. Although moscatilin has been reported to suppress tumor angiogenesis and growth, the anti-metastatic property of moscatilin has not been elucidated. The present results revealed that moscatilin inhibited metastatic behavior of HCC cells without cytotoxic fashion in highly invasive human HCC cell lines. Furthermore, moscatilin significantly suppressed the activity of urokinase plasminogen activator (uPA), but not matrix metalloproteinase (MMP)-2 and MMP-9. Interestingly, moscatilin-suppressed uPA activity was through down-regulation the protein level of uPA, and did not impair the uPA receptor and uPA inhibitory molecule (PAI-1) expressions. Meanwhile, the mRNA expression of uPA was inhibited via moscatilin in a concentration-dependent manner. In addition, the expression of phosphorylated Akt, rather than ERK1/2, was inhibited by moscatilin treatment. The expression of phosphor-IκBα, and -p65, as well as κB-luciferase activity were also repressed after moscatilin treatment. Transfection of constitutively active Akt (Myr-Akt) obviously restored the moscatilin-inhibited the activation of NF-κB and uPA, and cancer invasion in HCC cells. Taken together, these results suggest that moscatilin impedes HCC invasion and uPA expression through the Akt/NF-κB signaling pathway. Moscatilin might serve as a potential anti-metastatic agent against the disease progression of human HCC.

A Notch-Dependent Inflammatory Feedback Circuit between Macrophages and Cancer Cells Regulates Pancreatic Cancer Metastasis

Notch activation has been detected in pancreatic ductal adenocarcinoma (PDAC). However, its role in PDAC metastasis remains unknown. In this study, we identify a Notch-dependent feedback circuit between pancreatic cancer cells and macrophages, which contributes to PDAC metastasis. In this circuit, miR-124 regulated Notch signaling in cancer cells by directly targeting the Notch ligand Jagged 1. Autoamplified Notch signaling promoted the recruitment and activation of macrophages to a tumor-supporting M2-like phenotype via downstream IL8, CCL2, IL1α, and uPA paracrine signaling. In turn, activated macrophage-derived IL6 activated the oncogenic transcription factor STAT3 that directly repressed miR-124 genes via a conserved STAT3-binding site in their promoters, thereby promoting cancer cell epithelial-mesenchymal transition and invasion. Disrupting this circuit suppressed liver metastasis in mouse models. Thus, our study suggests that manipulation of this Notch-dependent circuit has a therapeutic potential for the treatment of PDAC metastasis. SIGNIFICANCE: This study provided potential therapeutic targets and robust preclinical evidence for PDAC treatment by interrupting feedback signaling between cancer cells and macrophages with targeted inhibitors.

How Different Are the Molecular Mechanisms of Nodal and Distant Metastasis in Luminal A Breast Cancer?

Lymph node status is one of the best prognostic factors in breast cancer, however, its association with distant metastasis is not straightforward. Here we compare molecular mechanisms of nodal and distant metastasis in molecular subtypes of breast cancer, with major focus on luminal A patients. We analyze a new cohort of 706 patients (MMCI_706) as well as an independent cohort of 836 primary tumors with full gene expression information (SUPERTAM_HGU133A). We evaluate the risk of distant metastasis, analyze targetable molecular mechanisms in Gene Set Enrichment Analysis and identify relevant inhibitors. Lymph node positivity is generally associated with NF-κB and Src pathways and is related to high risk (OR: 5.062 and 2.401 in MMCI_706 and SUPERTAM_HGU133A, respectively, p < 0.05) of distant metastasis in luminal A patients. However, a part (≤15%) of lymph node negative tumors at the diagnosis develop the distant metastasis which is related to cell proliferation control and thrombolysis. Distant metastasis of lymph node positive patients is mostly associated with immune response. These pro-metastatic mechanisms further vary in other molecular subtypes. Our data indicate that the management of breast cancer and prevention of distant metastasis requires stratified approach based on targeted strategies.

Epithelial Mesenchymal Transition and Progression of Breast Cancer Promoted by Diabetes Mellitus in Mice Are Associated with Increased Expression of Glycolytic and Proteolytic Enzymes

The development of breast cancer (BC) is influenced by age, overweight, obesity, metabolic syndrome, and diabetes mellitus (DM), which are associated with hyperglycemia, glucose intolerance, insulin resistance, and oxidative stress. High glucose concentration increases a metastatic phenotype in cultured breast cancer cells, promoting cell proliferation, reactive species production (ROS), epithelial mesenchymal transition (EMT), and expression of proteolytic enzymes. Our aim was to determine whether diabetes mellitus favor BC progression in mice and its association with changes in the content of ROS and glycolytic and proteolytic enzymes. Diabetes was induced in 7-week-old Balb/c mice, under 6-h fasting with a unique i. p. dose of streptozotocin 120 mg/kg. Furthermore, 4T1 breast cancer cells were injected beneath the nipple to induce tumors. G6PD, GAPDH, ENO1, uPA, uPAR, PAI-1, β-catenin, Snail, vimentin, and E-cadherin were measured by western blot and MPP-9 and MMP-2 by gel zymography. TBARS were measured as markers of the lipid peroxidation. Lower survival and increased tumor growth, together with marked EMT, were found in diabetic in comparison with nondiabetic mice. The effects of diabetes were associated with enhanced lipid peroxidation and higher levels of glycolytic (G6PD, GAPDH, and ENO1) and proteolytic (uPA, MMP-9) enzymes. Possibly, hyperglycemia and ROS led to faster progression of breast cancer in diabetic mice, fomenting EMT and the expression of glycolytic and proteolytic enzymes. These enzymes participate in the supply of energy and precursors for macromolecular biosynthesis and extracellular matrix degradation during breast cancer progression.

The expression of urokinase-type plasminogen activator system in upper tract urothelial carcinoma and its prognostic value after radical nephroureterectomy

BACKGROUND

To evaluate the expression pattern and prognostic role of the urokinase-type plasminogen activator (uPA) system in patients who underwent radical nephroureterectomy (RNU) for nonmetastatic upper tract urothelial carcinoma (UTUC).

METHODS

A total of 732 patients who were treated with RNU for clinically nonmetastatic UTUC comprised our analytical cohort. Immunohistochemical staining of uPA, uPA receptor (uPAR) and uPA inhibitor (PAI-1) was performed using Murine IgG1 monoclonal antibodies. Outcomes of interest were recurrence-free survival, cancer-specific survival, and overall survival.

RESULTS

The median age of the patients was 69.8 years and 56.6% of them were males. Overall, overexpression of uPA, uPAR, and PAI-1 was observed in 292 (39.9%), 346 (47.3%), and 345 (47.1%) patients, respectively. The uPA system components showed a statistically significant association with adverse clinicopathologic features such as lymphovascular invasion, multifocality, sessile tumors, and advanced pathologic stage (P < 0.01). On multivariable models, higher pathologic tumor stage, multifocality, and lymph node involvement were associated with RFS, OS, and CSS, but not the overexpression of uPA, uPAR, or PAR-1. In patients with organ-confined disease (≤pT2N0), however, uPA was significantly associated with RFS (hazard ratio [HR]: 2.04, 95% confidence interval [CI]: 1.21-3.43), OS (HR: 1.59, 95% CI:1.08-2.24) and CSS (HR: 2.55, 95% CI:1.44-4.52). uPA improved the predictive accuracy of a standard post-RNU model for all 3 endpoints, in organ-confined disease, by a prognostically significant margin.

CONCLUSIONS

Overexpression of uPA system components was associated with adverse clinicopathologic characteristics and survival outcomes on the univariable, but not multivariable analyses. uPA expression was an independent predictor of survival outcomes in patients with organ-confined disease. While the clinical value of the uPA system remains limited in this cohort, further studies are needed to identify a marker or constellation of markers of high predictive value to help in counseling and treatment planning of UTUC patients.

Muscarinic receptors modulate Nerve Growth Factor production in rat Schwann-like adipose-derived stem cells and in Schwann cells

Regenerative capability of the peripheral nervous system after injury is enhanced by Schwann cells (SCs) producing several growth factors. The clinical use of SCs in nerve regeneration strategies is hindered by the necessity of removing a healthy nerve to obtain the therapeutic cells. Adipose-derived stem cells (ASCs) can be chemically differentiated towards a SC-like phenotype (dASCs), and represent a promising alternative to SCs. Their physiology can be further modulated pharmacologically by targeting receptors for neurotransmitters such as acetylcholine (ACh). In this study, we compare the ability of rat dASCs and native SCs to produce NGF in vitro. We also evaluate the ability of muscarinic receptors, in particular the M2 subtype, to modulate NGF production and maturation from the precursor (proNGF) to the mature (mNGF) form. For the first time, we demonstrate that dASCs produce higher basal levels of proNGF and mature NGF compared to SCs. Moreover, muscarinic receptor activation, and in particular M2 subtype stimulation, modulates NGF production and maturation in both SCs and dASCs. Indeed, both cell types express both proNGF A and B isoforms, as well as mNGF. After M2 receptor stimulation, proNGF-B (25 kDa), which is involved in apoptotic processes, is strongly reduced at transcript and protein level. Thus, we demonstrate that dASCs possess a stronger neurotrophic potential compared to SCs. ACh, via M2 muscarinic receptors, contributes to the modulation and maturation of NGF, improving the regenerative properties of dASCs.

Therapeutics targeting the fibrinolytic system

The function of the fibrinolytic system was first identified to dissolve fibrin to maintain vascular patency. Connections between the fibrinolytic system and many other physiological and pathological processes have been well established. Dysregulation of the fibrinolytic system is closely associated with multiple pathological conditions, including thrombosis, inflammation, cancer progression, and neuropathies. Thus, molecules in the fibrinolytic system are potent therapeutic and diagnostic targets. This review summarizes the currently used agents targeting this system and the development of novel therapeutic strategies in experimental studies. Future directions for the development of modulators of the fibrinolytic system are also discussed.

The fibrinolytic system was originally identified to dissolve blood clots, and is shown to have important roles in other pathological processes, including cancer progression, inflammation, and thrombosis. Molecules or therapeutics targeting fibrinolytic system have been successfully used in the clinical treatments of cancer and thrombotic diseases. The clinical studies and experimental models targeting fibrinolytic system are reviewed by Haili Lin at Sanming First Hosipital, Mingdong Huang at Fuzhou University in China, and Peng Xu at A*STAR in Singapore to demonstrate fibrinolytic system as novel therapeutic targets. As an example, the inhibition of fibrinolytic system protein can be used to suppress cancer prolifieration and metastasis. This review also discusses the potential therapeutic effects of inhibitiors of fibrinolytic system on inflammatory disorders.

The urokinase-type plasminogen activator and inhibitors in resectable lung adenocarcinoma

BACKGROUND

The urokinase-type plasminogen activator (uPA) system is closely related to the occurrence and progression of cancer in many aspects. Previous studies demonstrated that the conclusions about the prognosis value of uPA, plasminogen activator inhibitor 1 (PAI-1) and plasminogen activator inhibitor 2 (PAI-2) in lung cancer are controversial, so this study was performed for the exploration of the predictive effect of uPA, PAI-1 and PAI-2 on the overall survival (OS) of resectable pulmonary adenocarcinoma patients.

METHODS

UPA, PAI-1 and PAI-2 expression levels were assayed by immunohistochemical staining based on tissue microarray (TMA) that is composed of formalin-fixed paraffin-embedded specimens from 84 resectable lung adenocarcinoma patients from July 2004 to June 2009. The relationship of IHC, mRNA expression levels of three molecules were investigated respectively. The three molecules' relationship with clinicopathologic parameters and OS was explored by Chi-square, Kaplan-Meier, and Cox regression analyses. The Cancer Genome Atlas (TCGA) database was used to analyze differential gene expressions of RNA-sequencing data of pulmonary adenocarcinoma and normal tissues, and Kaplan-Meier methods were adopted to confirm the prognostic value of uPA, PAI-1 and PAI-2 in resectable lung adenocarcinoma in TCGA database and the R package MethylMix was used to conduct an analysis integrating methylation data and gene expression of RNA-sequencing data based on TCGA.

RESULTS

UPA, PAI-1 and PAI-2 had much higher IHC expression levels in tumor than those in the normal tissues (uPA, Z = -10.511; PAI-1, Z = -4.836; PAI-2, Z = -6.794; all P < 0.0001). High DNA methylation level of gene uPA resulted in the decrease of its expression. In addition, expression level of PAI-2 was positively associated with tumor size (χ² = 8.372, P =  0.004). Multivariate analyses showed TNM stage III was an independent adverse prognostic factor (hazard ratio = 3.736, 95 % confidence interval = 1.097-12.72, P =  0.035). Kaplan-Meier method revealed that uPA, PAI-1 and PAI-2 expression levels were not related to the OS for 84 resectable lung adenocarcinoma patients. According to TCGA data, PAI-1 expression level was identified as a potential adverse predictor for prognosis of resectable lung adenocarcinoma (Gehan-Breslow-Wilcoxon test, P = 0.025).

CONCLUSIONS

Our data show that, the expression levels of uPA, PAI-1 and PAI-2 are significantly up-regulated in resectable lung adenocarcinoma. Besides, this study highlights PAI-1 as a latent adverse prognostic factor in resectable adenocarcinoma of lung.

Downregulation of uPAR promotes urokinase translocation into the nucleus and epithelial to mesenchymal transition in neuroblastoma

The urokinase system is involved in a variety of physiological processes, such as fibrinolysis, matrix remodeling, wound healing, and regeneration. Upon binding to its cognate receptor urokinase‐type plasminogen activator receptor (uPAR), urokinase‐type plasminogen activator (uPA) catalyzes the conversion of plasminogen to plasmin and the activation of matrix metalloproteases. Apart from this, uPA–uPAR interaction can lead to the activation of transcription factors, mitogen‐activated protein kinase signaling pathways and RTK cascades. Elevated expression of uPA and uPAR is markedly associated with cancer progression and metastasis and correlates with a poor prognosis in clinics. Targeting the urokinase system has proved to be effective in experimental models in vitro and in vivo, however, in clinics the inhibition of the uPA/uPAR system has fallen short of expectations, suggesting that the question of the functional relevance of uPA/uPAR system is far from being moot. Recently, using CRISPR/Cas9 technology, we have shown that uPAR knockout decreases the proliferation of neuroblastoma Neuro2a cells in vitro. In the present study we demonstrate that uPAR expression is essential for maintaining the epithelial phenotype in Neuro2a cells and that uPAR silencing promotes epithelial‐mesenchymal transition (EMT) and increased cell migration. Accordingly, uPAR knockout results in the downregulation of epithelial markers (E‐cadherin, occludin, and claudin‐5) and in the increase of mesenchymal markers (N‐cadherin, α‐smooth muscle actin, and interleukin‐6). In search of the molecular mechanism underlying these changes, we identified uPA as a key component. Two key insights emerged as a result of this work: in the absence of uPAR, uPA is translocated into the nucleus where it is presumably involved in the activation of transcription factors (nuclear factor κB and Snail) resulting in EMT. In uPAR‐expressing cells, uPAR functions as a uPA “trap” that binds uPA on the cell surface and promotes controlled uPA internalization and degradation in lysosomes.

Expression of urokinase-type plasminogen activator system in non-metastatic prostate cancer

PURPOSE

To investigate the prognostic role of expression of urokinase-type plasminogen activator system members, such as urokinase-type activator (uPA), uPA-receptor (uPAR), and plasminogen activator inhibitor-1 (PAI-1), in patients treated with radical prostatectomy (RP) for prostate cancer (PCa).

METHODS

Immunohistochemical staining for uPA system was performed on a tissue microarray of specimens from 3121 patients who underwent RP. Cox regression analyses were performed to investigate the association of overexpression of these markers alone or in combination with biochemical recurrence (BCR). Decision curve analysis was used to assess the clinical impact of these markers.

RESULTS

uPA, uPAR, and PAI-1 were overexpressed in 1012 (32.4%), 1271 (40.7%), and 1311 (42%) patients, respectively. uPA overexpression was associated with all clinicopathologic characteristics of biologically aggressive PCa. On multivariable analysis, uPA, uPAR, and PAI-1 overexpression were all three associated with BCR (HR: 1.75, p < 0.01, HR: 1.22, p = 0.01 and HR: 1.20, p = 0.03, respectively). Moreover, the probability of BCR increased incrementally with increasing cumulative number of overexpressed markers. Decision curve analysis showed that addition of uPA, uPAR, and PAI-1 resulted in a net benefit compared to a base model comparing standard clinicopathologic features across the entire threshold probability range. In subgroup analyses, overexpression of all three markers remained associated with BCR in patients with favorable pathologic characteristics.

CONCLUSION

Overexpression of uPA, uPAR, and PAI-1 in PCa tissue were each associated with worse BCR. Additionally, overexpression of all three markers is informative even in patients with favorable pathologic characteristics potentially helping clinical decision-making regarding adjuvant therapy and/or intensified follow-up.

Deficiency of Urokinase Plasminogen Activator May Impair β Cells Regeneration and Insulin Secretion in Type 2 Diabetes Mellitus

Background: The relationship between urokinase-type plasminogen activator (uPA) and the development of type 2 diabetes mellitus (T2DM) was investigated in the study by using mice and cell models, as well as patients with T2DM. Methods: In mice models, wild-type and uPA knockout (uPA-/-) BALB/c mice were used for induction of T2DM. In cell models, insulin secretion rate and β cell proliferation were assessed in normal and high glucose after treating uPA siRNA, uPA, or anti-uPA antibody. In our clinical study, patients with T2DM received an oral glucose-tolerance test, and the relationship between uPA and insulin secretion was assessed. Results: Insulin particles and insulin secretion were mildly restored one month after induction in wild-type mice, but not in uPA-/- mice. In cell models, insulin secretion rate and cell proliferation declined in high glucose after uPA silencing either by siRNA or by anti-uPA antibody. After treatment with uPA, β cell proliferation increased in normal glucose. In clinical study, patients with T2DM and higher uPA levels had better ability of insulin secretion than those with lower uPA levels. Conclusion: uPA may play a substantial role in insulin secretion, β cell regeneration, and progressive development of T2DM. Supplementation of uPA might be a novel approach for prevention and treatment of T2DM in the future.

pH-Sensitive Shell-Core Platform Block DNA Repair Pathway To Amplify Irreversible DNA Damage of Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is insensitive to either chemotherapy or endocrine therapy because of the powerful DNA reparation and the negative expression of surface antigens, which urgently claims for an effective approach to improve the prognosis. Herein, DNA repair blocker BRCA1 small interfering RNA (siRNA) was introduced with cisplatin (Pt) into the elaborately designed pH-sensitive shell-core platform to enhance the chemotherapeutic treatment effect by silencing the DNA repair related gene. In this platform, BRCA1 siRNA and Pt prodrug (Pro-Pt) were separately encapsulated in the porous outer shell and hydrophobic inner core with extremely high encapsulation efficiency and stability effectively preventing them from degradation during circulation. Suitable size and urokinase plasminogen activator analogues (uPA) with high affinity for the uPA receptor (uPAR) realized an excellent dual passive and active tumor targeting ability. Moreover, the exposed PEG hydrophilic chain prevented the nanoparticles (NPs) from precipitating by serum protein or inactivating by nuclease in the blood cycle. Most importantly, the degradable CaP (calcium ions and phosphate ions) shell with smart pH sensitivity would dissipate from NPs in the lysosomes to burst the lysosome membranes so as to guarantee the lysosomal escape and the sequential release of the siRNA and Pro-Pt where the BRCA1 siRNA blocked the DNA repairing pathway followed by reducing Pro-Pt to Pt for irreversible DNA damage. Hence, the uPA-SP@CaP NPs provided a promising strategy for high-efficiency treatment of TNBC along with bringing new hope for more patients.

Excess hepsin proteolytic activity limits oncogenic signaling and induces ER stress and autophagy in prostate cancer cells

The serine protease hepsin is frequently overexpressed in human prostate cancer (PCa) and is associated with matrix degradation and PCa progression in mice. Curiously, low expression of hepsin is associated with poor survival in different cancer types, and transgenic overexpression of hepsin leads to loss of viability in various cancer cell lines. Here, by comparing isogenic transfectants of the PCa cell line PC-3 providing inducible overexpression of wild-type hepsin (HPN) vs. the protease-deficient mutant HPN^S353A, we were able to attribute hepsin-mediated tumor-adverse effects to its excess proteolytic activity. A stem-like expression signature of surface markers and adhesion molecules, Notch intracellular domain release, and increased pericellular protease activity were associated with low expression levels of wild-type hepsin, but were partially lost in response to overexpression. Instead, overexpression of wild-type hepsin, but not of HPN^S353A, induced relocalization of the protein to the cytoplasm, and increased autophagic flux in vitro as well as LC3B punctae frequency in tumor xenografts. Confocal microscopy revealed colocalization of wild-type hepsin with both LC3B punctae as well as with the autophagy cargo receptor p62/SQSTM1. Overexpression of wild type, but not protease-deficient hepsin induced expression and nuclear presence of CHOP, indicating activation of the unfolded protein response and ER-associated protein degradation (ERAD). Whereas inhibitors of ER stress and secretory protein trafficking slightly increased viability, combined inhibition of the ubiquitin-proteasome degradation pathway (by bortezomib) with either ER stress (by salubrinal) or autophagy (by bafilomycin A1) revealed a significant decrease of viability during overexpression of wild-type hepsin in PC-3 cells. Our results demonstrate that a precise control of Hepsin proteolytic activity is critical for PCa cell fate and suggest, that the interference with ERAD could be a promising therapeutic option, leading to induction of proteotoxicity in hepsin-overexpressing tumors.

Metabolic flexibility in melanoma: A potential therapeutic target

Cutaneous melanoma (CM) represents one of the most metastasizing and drug resistant solid tumors. CM is characterized by a remarkable metabolic plasticity and an important connection between oncogenic activation and energetic metabolism. In fact, melanoma cells can use both cytosolic and mitochondrial compartments to produce adenosine triphosphate (ATP) during cancer progression. However, the CM energetic demand mainly depends on glycolysis, whose upregulation is strictly linked to constitutive activation of BRAF/MAPK pathway affected by BRAF^V600E kinase mutant. Furthermore, the impressive metabolic plasticity of melanoma allows the development of resistance mechanisms to BRAF/MEK inhibitors (BRAFi/MEKi) and the adaptation to microenvironmental changes. The metabolic interaction between melanoma cells and tumor microenvironment affects the immune response and CM growth. In this review article, we describe the regulation of melanoma metabolic alterations and the metabolic interactions between cancer cells and microenvironment that influence melanoma progression and immune response. Finally, we summarize the hallmarks of melanoma therapies and we report BRAF/MEK pathway targeted therapy and mechanisms of metabolic resistance.

Impact of uPA/PAI-1 and disseminated cytokeratin-positive cells in breast cancer

BACKGROUND

The protease uPA and its inhibitor PAI-1 play major roles in hemostasis and are also involved in cancer progression. This is mainly caused by their ability to degrade extracellular matrix-facilitating tumor cell migration. This study aimed to investigate the impact of uPA/PAI-1 and disseminated cytokeratin-positive cells (dCK+) on the outcome and the existence of synergistic effects.

METHODS

We retrospectively analyzed a cohort of 480 breast cancer cases with known uPA/PAI-1 and dCK+ status. uPA/PAI-1 was tested on fresh tumor samples using a commercial ELISA test. Bone marrow aspirates were investigated immunocytochemically for CK18.

RESULTS

DCK+ cells were identified in 23% of cases. uPA positivity was significantly associated with the occurrence of dCK+ cells (P = 0.028). uPA and PAI-1 were significantly associated with outcome in the subgroup of early-stage cases without chemotherapy. DCK+ cells alone were not prognostic. However, we found synergistic effects. In the subgroup of node-negative cases with and without chemotherapy, the prognostic impact of uPA and PAI-1 was enhanced in cases with additional dCK-positivity (triple +). In cases without chemotherapy, triple-positive status was independently prognostic (HR: 9.3 CI: 1.1-75) next to T stage.

CONCLUSIONS

uPA and PAI-1 seem to influence the metastatic potential of dCK+ cells, which underlines its important role in tumor progression.

Structural Biology and Protein Engineering of Thrombolytics

Myocardial infarction and ischemic stroke are the most frequent causes of death or disability worldwide. Due to their ability to dissolve blood clots, the thrombolytics are frequently used for their treatment. Improving the effectiveness of thrombolytics for clinical uses is of great interest. The knowledge of the multiple roles of the endogenous thrombolytics and the fibrinolytic system grows continuously. The effects of thrombolytics on the alteration of the nervous system and the regulation of the cell migration offer promising novel uses for treating neurodegenerative disorders or targeting cancer metastasis. However, secondary activities of thrombolytics may lead to life-threatening side-effects such as intracranial bleeding and neurotoxicity. Here we provide a structural biology perspective on various thrombolytic enzymes and their key properties: (i) effectiveness of clot lysis, (ii) affinity and specificity towards fibrin, (iii) biological half-life, (iv) mechanisms of activation/inhibition, and (v) risks of side effects. This information needs to be carefully considered while establishing protein engineering strategies aiming at the development of novel thrombolytics. Current trends and perspectives are discussed, including the screening for novel enzymes and small molecules, the enhancement of fibrin specificity by protein engineering, the suppression of interactions with native receptors, liposomal encapsulation and targeted release, the application of adjuvants, and the development of improved production systems.

MicroRNA-193a-3p suppresses the colorectal cancer cell proliferation and progression through downregulating the PLAU expression

Background

Colorectal cancer (CRC) is one of the leading causes of cancer-related death in China. Dysregulation of microRNAs (miRNAs) is involved in cancer development and progression. Our previous study showed an inverse relationship between miR-193a-3p expression and the prognosis of CRC. However, the exact biological functions of miR-193a-3p in CRC are still poorly understood. This study aimed to explore the role and mechanism of miR-193a-3p in CRC.

Methods

Real-time PCR and Western blotting were used to examine the expression levels of RNA and protein, respectively. A dual luciferase assay was performed to validate predicted targets of miR-193a-3p. Loss and gain-of-function studies were carried out to reveal the effects and potential mechanism of the miR-193a-3p in the proliferation, metastasis and angiogenesis of CRC cells.

Results

The expression levels of miR-193a-3p in human CRC cell lines were significantly decreased compared with that in normal colonic epithelium cell line. Furthermore, plasminogen activator urokinase (PLAU) was validated as a direct target gene of miR-193a-3p. Over-expression of miR-193a-3p inhibited proliferation, migration and angiogenesis of HT-29 cell, whereas forced expression of PLAU could rescue the inhibitory effects.

Conclusion

miR-193a-3p might inhibit CRC cell growth, migration and angiogenesis partly through targeting PLAU. MiR-193a-3p/PLAU axis might provide a potent therapeutic opportunity for aggressive CRC.