Prognosis in adenocarcinomas of lower oesophagus, gastro-oesophageal junction and cardia evaluated by uPAR-immunohistochemistry

The Urokinase Receptor (uPAR) as a "Trojan Horse" in Targeted Cancer Therapy: Challenges and Opportunities

Simple Summary

Discovered more than three decades ago, the urokinase-type plasminogen activator receptor (uPAR) has now firmly established itself as a versatile molecular target holding promise for the treatment of aggressive malignancies. The copious abundance of uPAR in virtually all human cancerous tissues versus their healthy counterparts has fostered a gradual shift in the therapeutic landscape targeting this receptor from function inhibition to cytotoxic approaches to selectively eradicate the uPAR-expressing cells by delivering a targeted cytotoxic insult. Multiple avenues are being explored in a preclinical setting, including the more innovative immune- or stroma targeting therapies. This review discusses the current state of these strategies, their potentialities, and challenges, along with future directions in the field of uPAR targeting.

Abstract

One of the largest challenges to the implementation of precision oncology is identifying and validating selective tumor-driving targets to enhance the therapeutic efficacy while limiting off-target toxicity. In this context, the urokinase-type plasminogen activator receptor (uPAR) has progressively emerged as a promising therapeutic target in the management of aggressive malignancies. By focalizing the plasminogen activation cascade and subsequent extracellular proteolysis on the cell surface of migrating cells, uPAR endows malignant cells with a high proteolytic and migratory potential to dissolve the restraining extracellular matrix (ECM) barriers and metastasize to distant sites. uPAR is also assumed to choreograph multiple other neoplastic stages via a complex molecular interplay with distinct cancer-associated signaling pathways. Accordingly, high uPAR expression is observed in virtually all human cancers and is frequently associated with poor patient prognosis and survival. The promising therapeutic potential unveiled by the pleiotropic nature of this receptor has prompted the development of distinct targeted intervention strategies. The present review will focus on recently emerged cytotoxic approaches emphasizing the novel technologies and related limits hindering their application in the clinical setting. Finally, future research directions and emerging opportunities in the field of uPAR targeting are also discussed.

The Soluble Urokinase-Type Plasminogen Activator Receptor as a Biomarker for Survival and Early Treatment Effect in Metastatic Colorectal Cancer

The soluble urokinase-type plasminogen activator receptor (suPAR) is prognostic for overall survival (OS) in colorectal cancer (CRC). Our study explored the association between baseline suPAR and OS and progression-free survival (PFS) in metastatic CRC (mCRC). It is also the first study to explore the association between the initial change in suPAR level and OS, PFS and the first CT response evaluation. The study included 132 patients with mCRC treated with chemotherapy (FOLFIRI) with or without an EGFR-inhibitor. Blood samples were drawn before the first treatment cycle and in between the first and second treatment cycle. suPAR levels were determined using an ELISA assay. Using the Kaplan-Meyer method, we demonstrated a significantly shorter OS for patients with suPAR levels above the median (HR = 1.79, 95%CI = 1.10-2.92, p = 0.01). We also showed association between plasma suPAR level, gender and performance status (PS). However, we could not show any association with PFS, and analysis on the change in suPAR level provided no significant results. The results showing association between baseline suPAR and OS are in line with previous findings.

Experimental and Clinical Evidence Supports the Use of Urokinase Plasminogen Activation System Components as Clinically Relevant Biomarkers in Gastroesophageal Adenocarcinoma

Simple Summary

Patients with gastric and oesophageal adenocarcinomas (GOCs) have short life expectancies as their tumours spread to other sites early. This is facilitated by the increased expression of the urokinase plasminogen activation system (uPAS); a feature of the majority of GOCs. There is increasing appreciation of the importance of uPAS expression in a range of cell types within the tumour microenvironment. Abundant clinical evidence indicates that altered expression of uPAS proteins is associated with worse outcomes, including time to tumour recurrence and patient survival. Emerging technologies, including liquid biopsy, suggest a role of uPAS for the detection of circulating tumour cells, which are responsible for the dissemination of cancers. We review and summarise pre-clinical and clinical data that supports the use of uPAS as a biomarker in GOC.

Abstract

Gastric and oesophageal cancers (GOCs) are lethal cancers which metastasise early and recur frequently, even after definitive surgery. The urokinase plasminogen activator system (uPAS) is strongly implicated in the invasion and metastasis of many aggressive tumours including GOCs. Urokinase plasminogen activator (uPA) interaction with its receptor, urokinase plasminogen activator receptor (uPAR), leads to proteolytic activation of plasminogen to plasmin, a broad-spectrum protease which enables tumour cell invasion and dissemination to distant sites. uPA, uPAR and the plasminogen activator inhibitor type 1 (PAI-1) are overexpressed in some GOCs. Accumulating evidence points to a causal role of activated receptor tyrosine kinase pathways enhancing uPAS expression in GOCs. Expression of these components are associated with poorer clinicopathological features and patient survival. Stromal cells, including tumour-associated macrophages and myofibroblasts, also express the key uPAS proteins, supporting the argument of stromal involvement in GOC progression and adverse effect on patient survival. uPAS proteins can be detected on circulating leucocytes, circulating tumour cells and within the serum; all have the potential to be developed into circulating biomarkers of GOC. Herein, we review the experimental and clinical evidence supporting uPAS expression as clinical biomarker in GOC, with the goal of developing targeted therapeutics against the uPAS.

Fluorescence guided intraluminal endoscopy in the gastrointestinal tract: A systematic review

BACKGROUND

Conventional endoscopy is based on full spectrum white light. However, different studies have investigated the use of fluorescence based endoscopy systems where the white light has been supplemented by infrared light and the use of relevant fluorophores. Fluorescence endoscopy utilizes the fluorescence emitted from a fluorophore, visualizing what is not visible to the naked eye.

AIM

To explore the feasibility of fluorescence endoscopy and evaluate its use in diagnosing and evaluating gastrointestinal disease.

METHODS

We followed the PRISMA guidelines for this systematic review. The research covered five databases; PubMed, Scopus, Web of Science, Embase, and the Cochrane Collection, including only studies in English and Scandinavian languages. Authors screened title and abstract for inclusion, subsequently full-text for inclusion according to eligibility criteria listed in the protocol. The risk of bias was assessed for all studies according to the Newcastle-Ottawa Scale. The authors extracted the data and reported the results in both text and tables.

RESULTS

We included seven studies in the systematic review after screening a total of 2769 papers. The most prominent fluorophore was indocyanine green (n = 6), and whereas one study (n = 1) used Bevacizumab 800-CW. Three studies investigated fluorescence endoscopy in detecting varices, adenomas in patients with familial adenomatous polyposis and neoplasms in the gastrointestinal tract. Four studies evaluated the usefulness of fluorescence endoscopy in assessing tumor invasion. Three of the four studies reported an exceptional diagnostic accuracy (93%, 89% and 88%) in assessing tumor invasion, thus representing better visualization and more correct diagnosis by fluorescence endoscopy compared with the conventional endoscopy. The relationship between the endoscopic findings, tumor invasion, and tumor vascularity was evaluated in two studies showing a significant correlation (^dP < 0.05 and ^bP < 0.01).

CONCLUSION

The use of fluorescence endoscopy is a promising method adding diagnostic value in the detection of neoplasia, adenomas, and assessment of tumor invasion within the gastrointestinal tract. More studies are needed to utilize the feasibility of fluorescence endoscopy compared with other endoscopic methods.

Expression of cancer stem cell markers is prognostic in metastatic gastroesophageal adenocarcinoma

Gastroesophageal adenocarcinoma is a common and highly lethal malignancy. Cancer stem cells (CSCs) have a key role in the development and progression of metastatic disease. While expression of CSC markers CD44, CD133 and aldehyde dehydrogenase 1 (ALDH1) in locoregional gastroesophageal cancer is known to be associated with poorer clinical outcomes, the significance of CSC marker expression in distal metastatic disease is unknown. We investigated the clinicopathological and prognostic associations of the CSC markers, CD44, CD133, and ALDH1, on metastatic deposits from gastroesophageal adenocarcinomas, and evaluated the association of CSC expression with urokinase-type plasminogen activator receptor (uPAR) expression. Of the 36 patients included in the study, 16 (44%) were positive for CD44, 13 (36%) were positive for CD133, and 26 (72%) were positive for ALDH1. CD44 expression was significantly associated with poorer overall survival (OS) in univariate [hazard ratio (HR) 2.9, 95% confidence interval (CI) 1.3-6.9, p=0.008] and multivariate analyses (HR 2.5, 95%CI 1.1-6.2, p=0.04). ALDH1 expression was significantly associated with poorer OS in univariate (HR 2.4, 95% CI 1.01-5.7, p=0.04) analysis but was not significant in multivariate analysis. Both CD44 and ALDH1 expression were significantly associated with uPAR expression. We found no association between CD133 expression and OS. CD44 expression on metastatic disease from gastroesophageal adenocarcinomas is an independent prognostic marker associated with poorer OS. These results expand current evidence to support the role of CSCs as biomarkers in metastatic gastroesophageal cancer.

Prognostic value of uPAR expression and angiogenesis in primary and metastatic melanoma

Angiogenesis is important for the progression of cutaneous melanoma. Here, we analyzed the prognostic impact of the angiogenic factor urokinase plasminogen activator resecptor (uPAR), vascular proliferation index (VPI) and tumor necrosis as a measure of hypoxia in a patient series of nodular melanomas (n = 255) and matched loco-regional metastases (n = 78). Expression of uPAR was determined by immunohistochemistry and VPI was assessed by dual immunohistochemistry using Factor-VIII/Ki67 staining. Necrosis was recorded based on HE-slides. As novel findings, high uPAR expression and high VPI were associated with each other, and with increased tumor thickness, presence of tumor necrosis, tumor ulceration, increased mitotic count and reduced cancer specific survival in primary melanoma. In matched cases, VPI was decreased in metastases, whereas the frequency of necrosis was increased. Our findings demonstrate for the first time the impact on melanoma specific survival of uPAR expression and VPI in primary tumors, and of increased necrosis as an indicator of tumor hypoxia in loco-regional metastases. These findings support the importance of tumor angiogenesis in melanoma aggressiveness, and suggest uPAR as an indicator of vascular proliferation and a potential biomarker in melanoma.

Silencing of uPAR via RNA interference inhibits invasion and migration of oral tongue squamous cell carcinoma

Overexpression of urokinase-type plasminogen activator receptor (uPAR) has been implicated in promoting tumor invasion in various cancer types, including oral tongue squamous cell carcinoma (OTSCC); therefore, the effect of suppressing uPAR expression on the invasive and metastatic potential of OTSCC was investigated. A total of 65 paraffin-embedded tissues were obtained from patients with OTSCC. Immunohistochemistry was used to determine the expression level of uPAR. The Ts cells transfected with short hairpin RNA targeting uPAR were constructed and validated. The cells were used in a number of in vitro analyses, including migration, invasion and western blot analysis assays. Furthermore, a mouse lung metastatic model was used to detect the metastatic ability of OTSCC cells in the lungs. OTSCC cell metastasis and relapse were determined to be associated with uPAR immunopositivity. Inhibition of uPAR expression in Ts cells demonstrated a 40% decrease in migration and a 60% decrease in invasion in vitro, with an associated downregulation of matrix metalloprotease (MMP)-2, MMP-9 and phosphorylated extracellular signal-regulated kinase. In vivo analysis indicated a 90% decrease in the number of mice bearing macroscopic lung metastases. In conclusion, the present study demonstrated that the targeting of uPAR-inhibited cellular proliferation and invasion would provide a potential treatment for OTSCC in the future.

The urokinase plasminogen activation system in gastroesophageal cancer: A systematic review and meta-analysis

Background

The urokinase plasminogen activation (uPA) system is a crucial pathway for tumour invasion and establishment of metastasis. Although there is good evidence that uPA system expression is a clinically relevant biomarker in some solid tumours, its role in gastroesophageal cancer is uncertain.

Results

We identified 22 studies encompassing 1966 patients which fulfilled the inclusion criteria. uPA, uPAR, or PAI-1 expression is significantly associated with high risk clinicopathological features. High uPA expression is associated with a shorter RFS (HR 1.90 95% 1.16–3.11, p = 0.01) and OS (HR 2.21 95% CI 1.74–2.80, p < 0.0001). High uPAR expression is associated with poorer OS (HR 2.21 95%CI 1.82–2.69, p < 0.0001). High PAI-1 expression is associated with shorter RFS (HR 1.96 96% CI 1.07–3.58, p = 0.03) and OS (HR 1.84 95%CI 1.28–2.64, p < 0.0001). There was no significant association between PAI-2 expression and OS (HR 0.97 95%CI 0.48–1.94, p < 0.92) although data was limited.

Materials and Methods

We undertook a systematic review evaluating expression of uPA, urokinase plasminogen activator receptor (uPAR), plasminogen activator inhibitor-1 (PAI-1/SerpinE1) and plasminogen activator inhibitor-2 (PAI-2/SerpinB2) on primary oesophageal, gastro-oesophageal junction, and gastric adenocarcinomas. We performed a meta-analysis of clinicopathological associations, overall survival (OS) and recurrence free survival (RFS).

Conclusions

We conclude that the uPA system is a clinically relevant biomarker in primary gastroesophageal cancer, with higher expression of uPA, uPAR and PAI-1 associated with higher risk disease and poorer prognosis. This also highlights the potential utility of the uPA system as a therapeutic target for improved treatment strategies.

Urokinase-type plasminogen activator receptor (uPAR), tissue factor (TF) and epidermal growth factor receptor (EGFR): tumor expression patterns and prognostic value in oral cancer

Background

Tumor-specific biomarkers are a prerequisite for the development of targeted imaging and therapy in oral squamous cell carcinoma (OSCC). urokinase-type Plasminogen Activator Receptor (uPAR), Tissue Factor (TF) and Epidermal Growth Factor Receptor (EGFR) are three biomarkers that exhibit enhanced expression in many types of cancers, and have been investigated as potential biomarkers for targeted strategies and prognostication. The aim of the study was to investigate the expression patterns of uPAR, TF and EGFR and their potential prognostic value in OSCC.

Methods

Immunohistochemical expression of uPAR, TF and EGFR in tumor resection specimens from 191 patients with primary OSCC was analyzed. Overall (OS) and disease-free survival (DFS) was calculated. Associations between biomarker expression, clinicopathological factors and patient survival was analyzed using the Cox proportional hazards model for univariate and multivariate analysis, log rank and Kaplan-Meier statistics.

Results

uPAR and TF exhibited a highly tumor-specific expression pattern while EGFR also showed expression in normal tissues outside the tumor compartment. The overall positive expression rate of uPAR, TF and EGFR was 95%, 58% and 98%, respectively. High uPAR expression across the entire cohort was negatively associated with OS (p = 0.031, HR = 1.595 (95%CI 1.044–2.439)) in univariate analysis. The 5-year OS for high and low uPAR expression was 39% and 56%, respectively. The expression of TF and EGFR was not associated with survival outcome.

Conclusions

This study may suggest that uPAR and TF could potentially be attractive targets for molecular imaging and therapy in OSCC due to high positive expression rates and tumor-specific expression patterns. High uPAR expression was significantly associated with a reduced survival. uPAR seems to be a prognostic biomarker in oral cancer.

Inflammatory biomarkers and cancer: CRP and suPAR as markers of incident cancer in patients with serious nonspecific symptoms and signs of cancer

In Denmark, patients with serious nonspecific symptoms and signs of cancer (NSSC) are referred to the diagnostic outpatient clinics (DOCs) where an accelerated cancer diagnostic program is initiated. Various immunological and inflammatory biomarkers have been associated with cancer, including soluble urokinase plasminogen activator receptor (suPAR) and the pattern recognition receptors (PRRs) pentraxin-3, mannose-binding lectin, ficolin-1, ficolin-2 and ficolin-3. We aimed to evaluate these biomarkers and compare their diagnostic ability to classical biomarkers for diagnosing cancer in patients with NSSC. Patients were included from the DOC, Department of Infectious Diseases, Copenhagen University Hospital Hvidovre. Patients were given a final diagnosis based on the combined results from scans, blood work and physical examination. Weight loss, Charlson score and previous cancer were registered on admission, and plasma concentrations of biomarkers were measured. The primary outcome was incident cancer within 1 year. Out of 197 patients included, 39 patients (19.8%) were diagnosed with cancer. Patients with cancer were significantly older and had a higher burden of comorbidities and previous cancer diagnoses compared to patients who were not diagnosed with cancer. Previous cancer, C-reactive protein (CRP) and suPAR were significantly associated with newly diagnosed cancer during follow-up in multiple logistic regression analyses adjusted for age, sex and CRP. Neither any of the PRRs investigated nor self-reported weight loss was associated with cancer. In this study, previous cancer, CRP and suPAR were significantly associated with cancer diagnosis in patients with NSSC. Ficolin-1-3, MBL and pentraxin-3 were not associated with cancer.

Prognostic Impact of Urokinase Plasminogen Activator Receptor Expression in Pancreatic Cancer: Malignant Versus Stromal Cells

The urokinase plasminogen activator receptor (uPAR) has been proposed as a potential prognostic factor for various malignancies. The aim of this study is to assess the prognostic value of uPAR expression in neoplastic and stromal cells of patients with pancreatic adenocarcinoma. Urokinase plasminogen activator receptor expression was determined by immunohistochemistry in 122 pancreatic ductal adenocarcinomas. Kaplan-Meier and Cox regression analyses were used to determine the association with survival. Respectively 66%, 82% and 62% of patients with pancreatic cancer expressed uPAR in neoplastic cells, stromal, and in both combined. Multivariate analysis showed a significant inverse association between uPAR expression in both neoplastic and stromal cells and overall survival. The prognostic impact of uPAR in stromal cells is substantial, but not as pronounced as that of uPAR expression in neoplastic cells. This study suggests a role for uPAR as a biomarker to single out higher risk subgroups of patients with pancreatic cancer.

Carbohydrate antigen 19-9 is a useful prognostic marker in esophagogastric junction adenocarcinoma

The incidence rate of esophagogastric junction (EGJ) adenocarcinoma has been rapidly increasing worldwide. Carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) are major serum tumor markers in gastrointestinal cancers. However, the role of these markers in EGJ adenocarcinoma has not been thoroughly investigated. A total of 211 patients with EGJ adenocarcinoma who underwent surgery or endoscopic submucosal dissection at two academic institutions, Kumamoto University Hospital or Kyushu University Hospital between January 1996 and March 2014, were eligible for this study. Serum CEA and CA19-9 were examined within 1 month before resection. The cut-off values for CEA and CA19-9 were set at 5.0 ng/mL and 37 U/mL, respectively. The clinicopathological features and prognostic roles of the markers were examined using univariate and multivariate analyses. The positive ratios for preoperative CEA (>5.0 ng/mL) and CA19-9 (>37 U/mL) were 20.3% and 12.9%, respectively. The positive ratio of CEA and CA19-9 was significantly higher in patients with tumors invading muscular or deeper layers (P = 0.002 and <0.001, respectively). Cox proportional hazards model revealed that CA19-9 positivity, but not CEA positivity, was an independent prognostic factor in patients with EGJ adenocarcinoma for cancer-specific survival (multivariate hazard ratio [HR] = 3.89, 95% confidence interval [CI] 1.41-10.33; P = 0.010) and overall survival (multivariate HR = 2.43, 95% CI 1.03-5.35; P = 0.043). Preoperative serum CA19-9 is a useful prognostic marker in patients with EGJ adenocarcinoma.

uPAR Expression Pattern in Patients with Urothelial Carcinoma of the Bladder--Possible Clinical Implications

The objective of the present study was to confirm the expression and localisation pattern of the urokinase-type plasminogen activator receptor (uPAR) focusing on its possible clinical relevance in patients with urothelial neoplasia of the bladder. uPAR is a central molecule in tissue remodelling during cancer invasion and metastasis and is an established prognostic marker in various cancer diseases other than bladder cancer. Formalin-fixed and paraffin-embedded tumour-tissue blocks from 186 patients treated with radical cystectomy were analysed. uPAR expression was scored as either negative or positive as well as by the actual score. Separate scores were obtained for cancer cells, macrophages and myofibroblasts at the invasive front and in tumour core. We were able to confirm, in an independent patient cohort, the tissue expression and localisation pattern of uPAR as investigated by Immunohistochemistry as well as a significant association between uPAR positivity and increasing tumour stage and tumour grade. This demonstrates the robustness of our previous and current findings. In addition the association between uPAR positive myofibroblasts and poor survival was reproduced. The highest hazard ratios for survival were seen for uPAR positive myofibroblasts both at the invasive front and in tumour core. Evaluating uPAR expression by the actual score showed a significant association between uPAR positive myofibroblasts in tumour core and an increased risk of cancer specific mortality. Our investigations have generated new and valuable biological information about the cell types being involved in tumour invasion and progression through the plasminogen activation system.

Systematic review and meta-analysis of immunohistochemical prognostic biomarkers in resected oesophageal adenocarcinoma

BACKGROUND

Oesophageal adenocarcinoma (OAC) is one of the fastest rising malignancies with continued poor prognosis. Many studies have proposed novel biomarkers but, to date, no immunohistochemical markers of survival after oesophageal resection have entered clinical practice. Here, we systematically review and meta-analyse the published literature, to identify potential biomarkers.

METHODS

Relevant articles were identified via Ovid medline 1946-2013. For inclusion, studies had to conform to REporting recommendations for tumor MARKer (REMARK) prognostic study criteria. The primary end-point was a pooled hazard ratio (HR) and variance, summarising the effect of marker expression on prognosis.

RESULTS

A total of 3059 articles were identified. After exclusion of irrelevant titles and abstracts, 214 articles were reviewed in full. Nine molecules had been examined in more than one study (CD3, CD8, COX-2, EGFR, HER2, Ki67, LgR5, p53 and VEGF) and were meta-analysed. Markers with largest survival effects were COX-2 (HR=2.47, confidence interval (CI)=1.15-3.79), CD3 (HR=0.51, 95% CI=0.32-0.70), CD8 (HR=0.55, CI=0.31-0.80) and EGFR (HR=1.65, 95% CI=1.14-2.16).

DISCUSSION

Current methods have not delivered clinically useful molecular prognostic biomarkers in OAC. We have highlighted the paucity of good-quality robust studies in this field. A genome-to-protein approach would be better suited for the development and subsequent validation of biomarkers. Large collaborative projects with standardised methodology will be required to generate clinically useful biomarkers.

Urokinase-type plasminogen activator receptor (uPAR) expression is associated with T-stage and survival in urothelial carcinoma of the bladder

OBJECTIVES

To evaluate the expression-and localization pattern of the urokinase-type plasminogen activator receptor (uPAR), focusing on its clinical implications in patients with urothelial neoplasia of the bladder treated with radical cystectomy. uPAR is a central molecule in tissue remodeling during cancer invasion and metastasis and is an established prognostic marker in cancer. The expression and localization of uPAR and its prognostic significance is only limitedly investigated in urothelial bladder neoplasia.

MATERIALS AND METHODS

The expression-and localization pattern of uPAR was investigated in formalin-fixed paraffin-embedded tumor tissue from 149 patients treated with radical cystectomy between 1988 and 2005. uPAR expression was determined by immunohistochemistry and scored as either negative or positive. Separate values were obtained for cancer cells, macrophages, and myofibroblasts at the invasive front and tumor core, respectively. Statistical analyses were performed to evaluate the association of uPAR localization and score with clinicopathologic covariates and survival.

RESULTS

uPAR positivity was seen in 122/137 (89%) and 118/149 (74%) of the neoplasias at the invasive front and tumor core, respectively. uPAR was primarily expressed by myofibroblasts and macrophages in the surrounding stroma as well as some cancer cells. A significant association between uPAR positivity and T-stage as well as grade was found for all 3 cell types in tumor core (P ≤ 0.04 for all comparisons). In univariate analysis, the uPAR positive group had a shorter survival than the uPAR negative group (hazard ratio = 2.39; 95% CI: 1.15-5.01; P = 0.020).

CONCLUSIONS

The expression of uPAR is a possible prognostic marker that could be useful in identification of patients with aggressive, highly invasive tumors that could benefit from additional chemotherapy or more intensive follow-up after cystectomy.

Long noncoding RNA HOTAIR as an independent prognostic marker in cancer: a meta-analysis

BACKGROUND

HOTAIR, a newly discovered long intergenic noncoding RNA (lincRNA), has been reported to be aberrantly expressed in many types of cancers. This meta-analysis summarizes its potential role as a biomarker in malignancy.

METHODS

A quantitative meta-analysis was performed through a systematic search in Pubmed, Medline and Web of Science for eligible papers on the prognostic impact of HOTAIR in cancer from inception to Feb. 28, 2014. Pooled hazard ratios (HRs) with 95% confidence interval (95% CI) were calculated to summarize the effect.

RESULTS

Nineteen studies were included in the study, with a total of 2033 patients. A significant association was observed between high HOTAIR expression and poor overall survival (OS) in patients with cancer (pooled HR 2.22, 95% CI: 1.68-2.93). Place of residence (Asian or Western countries), type of cancer (digestive or non-digestive disease), sample size (more or less than 100), and paper quality (score more or less than 85%) did not alter the significant predictive value of HOTAIR in OS from various kinds of cancer but preoperative status did. By combining HRs from Cox multivariate analyses, we found that HOTAIR expression was an independent prognostic factor for cancer patients (pooled HR 2.26, 95% CI: 1.62-3.15). Subgroup analysis showed that HOTAIR abundance was an independent prognostic factor for cancer metastasis (HR 3.90, 95% CI: 2.25-6.74). For esophageal carcinoma, high HOTAIR expression was significantly associated with TNM stage (III/IV vs. I/II: OR 6.90, 95% CI: 2.81-16.9) without heterogeneity. In gastric cancer, HOTAIR expression was found to be significantly associated with lymph node metastases (present vs. absent: OR 4.47, 95% CI: 1.88-10.63) and vessel invasion (positive vs. negative: OR 2.88, 95% CI: 1.38-6.04) without obvious heterogeneity.

CONCLUSIONS

HOTAIR abundance may serve as a novel predictive factor for poor prognosis in different types of cancers in both Asian and Western countries.

Urokinase-type plasminogen activator receptor (uPAR) on tumor-associated macrophages is a marker of poor prognosis in colorectal cancer

Patients were identified from a population-based prospective study of 4990 individuals with symptoms associated with colorectal cancer (CRC). A total of 244 CRC tissue samples were available for immunohistochemical staining of uPAR, semiquantitatively scored at the invasive front, and in the tumor core on cancer cells, macrophages, and myofibroblasts. In addition, the levels of the intact and cleaved uPAR-forms in blood from the same patients are evaluated in this study. In a univariate analysis, the number of uPAR-positive versus uPAR-negative macrophages (HR = 2.26, [95% CI: 1.39-3.66, P = 0.0009]) and cancer cells (HR=1.49, [95% CI: 1.01-2.20, P = 0.047]) located in the tumor core were significantly associated to overall survival. In a multivariate analysis, uPAR-positive versus uPAR-negative macrophages located in the tumor core showed the best separation of patients with positive score associated to poor prognosis (HR = 1.84 [95% CI: 1.12-3.04, P = 0.017]). In a multivariate analysis including clinical covariates and soluble uPAR(I), the latter was significantly associated to overall survival (HR = 2.68 [95% CI: 1.90-3.79, P < 0.0001]) and uPAR-positive macrophages in the tumor core remained significantly associated to overall survival (HR = 1.81 [95% CI: 1.08-3.01, P = 0.023]). Membrane-bound uPAR showed additive effects with the circulating uPAR(I) and stage, giving a hazard ratio of 12 between low and high scores. Thus, combining stage, uPAR(I) in blood and uPAR on macrophages in the tumor core increase the prognostic precision more than tenfold, as compared to stage alone.

Downregulation of galectin-3 causes a decrease in uPAR levels and inhibits the proliferation, migration and invasion of hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related mortality worldwide. Galectin-3 (Gal-3), a multifunctional β-galactoside-binding protein, is highly expressed and associated with the prognosis of HCC. However, the functions of Gal-3 in HCC cells are not fully understood. To address the function of Gal-3 in HCC cells, we used small interfering RNA (siRNA) to knock down Gal-3 expression in HepG2, an HCC cell line. We found that in vitro the silencing of Gal-3 decreased the proliferative activity, colony formation ability, migratory and invasive potential of HepG2 cells. The silencing of Gal-3 significantly decreased the mRNA and protein levels of urokinase-type plasminogen activator receptor (uPAR) as well as uPAR's downstream signaling transduction pathway, including phosphorylation of AKT. Furthermore, the downregulation of Gal-3 by siRNA resulted in significantly decreased activity of the MEK/ERK signaling pathway, and the treatment of HepG2 cells with MEK/ERK inhibitor U0126 significantly reduced the mRNA and protein levels of uPAR. Taken together, our results suggest that Gal-3 modulates uPAR expression via the MEK/ERK pathway, and that Gal-3 may be a potential therapeutic target for the treatment of HCC.

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

Currently, there are several studies supporting the role of urokinase-type plasminogen activator (uPA) system in cancer. The association of uPA to its receptor triggers the conversion of plasminogen into plasmin. This process is regulated by the uPA inhibitors (PAI-1 and PAI-2). Plasmin promotes degradation of basement membrane and extracellular matrix (ECM) components as well as activation of ECM latent matrix metalloproteases. Degradation and remodeling of the surrounding tissues is crucial in the early steps of tumor progression by facilitating expansion of the tumor mass, release of tumor growth factors, activation of cytokines as well as induction of tumor cell proliferation, migration, and invasion. Hence, many tumors showed a correlation between uPA system component levels and tumor aggressiveness and survival. Therefore, this review summarizes the structure of the uPA system, its contribution to cancer progression, and the clinical relevance of uPA family members in cancer diagnosis. In addition, the review evaluates the significance of uPA system in the development of cancer-targeted therapies.

Histopathological growth pattern, proteolysis and angiogenesis in chemonaive patients resected for multiple colorectal liver metastases

The purpose of this study was to characterise growth patterns, proteolysis, and angiogenesis in colorectal liver metastases from chemonaive patients with multiple liver metastases. Twenty-four patients were included in the study, resected for a median of 2.6 metastases. The growth pattern distribution was 25.8% desmoplastic, 33.9% pushing, and 21% replacement. In 20 patients, identical growth patterns were detected in all metastases, but in 8 of these patients, a second growth pattern was also present in one or two of the metastases. In the remaining 4 patients, no general growth pattern was observed, although none of the liver metastases included more than two growth patterns. Overall, a mixed growth pattern was demonstrated in 19.3% of the liver metastases. Compared to metastases with pushing, those with desmoplastic growth pattern had a significantly up-regulated expression of urokinase-type plasminogen activator receptor (P = 0.0008). Angiogenesis was most pronounced in metastases with a pushing growth pattern in comparison to those with desmoplastic (P = 0.0007) and replacement growth pattern (P = 0.021). Although a minor fraction of the patients harboured metastases with different growth patterns, we observed a tendency toward growth pattern uniformity in the liver metastases arising in the same patient. The result suggests that the growth pattern of liver metastases is not a random phenomenon.