Pre-operative urinary cathepsin D is associated with survival in patients with renal cell carcinoma

Urinary concentration of Cathepsin D as a relievable marker of preeclampsia

BACKGROUND

The early and accurate diagnosis of preeclampsia is crucial to avoid serious complications for both the mother and baby. However, the current diagnostic methods are limited, and there is a need for new diagnostic biomarkers. Previous studies have shown that cathepsin D (CTD) participates in the pathophysiology of preeclampsia and is present in urine samples, making it a potential biomarker for the disease. This study aimed to compare urinary and serum levels of CTD in preeclamptic and normotensive women and analyze its potential role as a diagnostic biomarker in preeclampsia.

METHODS

The study included thirty-nine patients with preeclampsia and twelve normotensive pregnant women as controls. Biomarkers were determined using Multiplex Assay kit, and serum prolactin (Prl) and urinary TNF-α levels were also evaluated. Statistical analysis was conducted using the Mann-Whitney U test.

RESULTS

We found that urinary and serum CTD levels were significantly higher in the preeclampsia group than in the normotensive group, suggesting that CTD could be a diagnostic biomarker for preeclampsia. No significant differences were found in the levels of serum prolactin or urinary TNF-α between the two groups.

CONCLUSIONS

The study provides evidence that non-invasive biological samples such as urine can be used to improve new therapeutic strategies for the early management of preeclampsia.

Prognostic role of the immunohistochemical expression of proteins related to the renin-angiotensin system pathway in nonmetastatic clear cell renal cell carcinoma

INTRODUCTION

Stage migration has been observed in renal cell carcinoma (RCC) in recent decades; however, mortality rates have continuously increased in some countries. Tumoral factors have been characterized as major predictors of RCC. Nonetheless, this concept can be improved by combining these tumoral factors with other variables, including biomolecular factors.

PURPOSE

This study aimed to assess the immunohistochemical (IHC) expression and prognostic value of renin (REN), erythropoietin (EPO), and cathepsin D (CTSD), and to evaluate whether the concomitant expression of these markers can influence the prognostic outcomes in patients without metastasis.

MATERIAL AND METHODS

In total, 729 patients with clear cell RCC (ccRCC) who underwent surgical treatment between 1985 and 2016 were evaluated. All the cases in the tumor bank were reviewed by dedicated uropathologists. The IHC expression patterns of the markers were assessed using a tissue microarray. REN and EPO were classified as "positive" or "negative" expression. CTSD was grouped into "absent or weak expression" or "strong expression." Associations between clinical and pathological variables and the studied markers, in addition to 10-year overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival rates, were described.

RESULTS

REN and EPO expressions were positive in 70.6% and 86.6% of patients, respectively. Absent or weak and strong expressions of CTSD were observed in 58.2% and 41.3% of the patients, respectively. EPO expression had no impact on survival rates even when assessed concomitantly with REN. Negative REN expression was associated with advanced age, preoperative anemia, larger tumors, perirenal fat, hilum or renal sinus infiltration, microvascular invasion, necrosis, high nuclear grade, and clinical stages III to IV. In contrast, strong CTSD expression was associated with poor prognostic variables. The expression patterns of REN and CTSD were unfavorable predictors of the 10-year OS and CSS. In particular, the combination of negative REN and strong CTSD expression had a negative impact on these rates, including a higher risk of recurrence.

CONCLUSION

Loss of REN expression and strong CTSD expression were independent prognostic factors in nonmetastatic ccRCC, particularly when the concomitant expression pattern of both markers was present. EPO expression did not influence survival rates in this study.

Characterization of the pVHL Interactome in Human Testis Using High-Throughput Library Screening

Simple Summary

The von Hippel–Lindau (pVHL) tumor suppressor is a protein that regulates the normal cell adaptation to low oxygen concentrations. When its function is altered by inherited or acquired mutation pVHL becomes causative of a familiar predisposition to develop different types of cancers. Besides this role, pVHL is also thought to have other relevant cell functions, and studies in mice demonstrated that this protein is crucial for correct testis development and sperm maturation. By scanning the testis-specific library, we identified 55 novel proteins that interact with the human pVHL, with many of them directly participating in metabolic pathways frequently altered in cancer. Furthermore, our results suggest that pVHL may be also important for correct gonad function in men.

Abstract

Functional impairment of the von Hippel–Lindau tumor suppressor (pVHL) is causative of a familiar increased risk of developing cancer. As an E3 substrate recognition particle, pVHL marks the hypoxia inducible factor 1α (HIF-1α) for degradation in normoxic conditions, thus acting as a key regulator of both acute and chronic cell adaptation to hypoxia. The male mice model carrying VHL gene conditional knockout presents significant abnormalities in testis development paired with defects in spermatogenesis and infertility, indicating that pVHL exerts testis-specific roles. Here we aimed to explore whether pVHL could have a similar role in humans by performing a testis-tissue library screening complemented with in-depth bioinformatics analysis. We identified 55 novel pVHL binding proteins directly involved in spermatogenesis, cell differentiation and reproductive metabolism. In addition, computational investigation of these new interactors identified multiple pVHL-specific binding motifs and demonstrated that somatic mutations described in human cancers reside in these binding regions. Collectively, these findings suggest that, in addition to its role in cancer formation, pVHL may also be pivotal in normal gonadal development in humans.

Neither creatinine- nor cystatin C-estimated glomerular filtration rate is optimal in oncology patients treated with targeted agents

Background

In the last decade, there has been an increase in the use of anti-angiogenic drugs as treatment for metastatic malignancies. However, use of these targeted therapies could induce both glomerular and tubular damage. Also during targeted therapy, the lysosomal protease cathepsin D is released from the tumour, which is inhibited by the protease inhibitor cystatin C. The aim of this study is to determine if use of cystatin C-estimated glomerular filtration rate (eGFR) is applicable to a patient cohort treated with targeted agents.

Methods

A cohort of 80 patients with various malignancies were continuously recruited and prospectively analysed. Serum and urinary biochemical analytes for renal toxicities were assessed at different time points during treatment. The association between serum cystatin C and cathepsin D was also determined.

Results

A decrease in serum cystatin C concentrations (1.03 versus 0.90 mg/L; P < 0.001), together with an increase in cystatin C-eGFR (71 versus 89 mL/min/1.73 m2; P = 0.002) was observed during therapy, compared with baseline. This decrease in cystatin C concentrations was correlated with cathepsin D (r = 0.307; P < 0.001), which was released from the tumour during targeted therapy. Further analysis demonstrated cathepsin D-mediated proteolysis of cystatin C in serum.

Conclusions

Cystatin C concentrations were decreased during targeted therapy due to cathepsin D-mediated proteolysis. Cystatin C-eGFR is therefore not considered a suitable marker for assessing kidney function in oncology patients, and other techniques to estimate the GFR have to be applied in this patient population.

Methods for the evaluation of biomarkers in patients with kidney and liver diseases: multicentre research programme including ELUCIDATE RCT

Background

Protein biomarkers with associations with the activity and outcomes of diseases are being identified by modern proteomic technologies. They may be simple, accessible, cheap and safe tests that can inform diagnosis, prognosis, treatment selection, monitoring of disease activity and therapy and may substitute for complex, invasive and expensive tests. However, their potential is not yet being realised.

Design and methods

The study consisted of three workstreams to create a framework for research: workstream 1, methodology – to define current practice and explore methodology innovations for biomarkers for monitoring disease; workstream 2, clinical translation – to create a framework of research practice, high-quality samples and related clinical data to evaluate the validity and clinical utility of protein biomarkers; and workstream 3, the ELF to Uncover Cirrhosis as an Indication for Diagnosis and Action for Treatable Event (ELUCIDATE) randomised controlled trial (RCT) – an exemplar RCT of an established test, the ADVIA Centaur® Enhanced Liver Fibrosis (ELF) test (Siemens Healthcare Diagnostics Ltd, Camberley, UK) [consisting of a panel of three markers – (1) serum hyaluronic acid, (2) amino-terminal propeptide of type III procollagen and (3) tissue inhibitor of metalloproteinase 1], for liver cirrhosis to determine its impact on diagnostic timing and the management of cirrhosis and the process of care and improving outcomes.

Results

The methodology workstream evaluated the quality of recommendations for using prostate-specific antigen to monitor patients, systematically reviewed RCTs of monitoring strategies and reviewed the monitoring biomarker literature and how monitoring can have an impact on outcomes. Simulation studies were conducted to evaluate monitoring and improve the merits of health care. The monitoring biomarker literature is modest and robust conclusions are infrequent. We recommend improvements in research practice. Patients strongly endorsed the need for robust and conclusive research in this area. The clinical translation workstream focused on analytical and clinical validity. Cohorts were established for renal cell carcinoma (RCC) and renal transplantation (RT), with samples and patient data from multiple centres, as a rapid-access resource to evaluate the validity of biomarkers. Candidate biomarkers for RCC and RT were identified from the literature and their quality was evaluated and selected biomarkers were prioritised. The duration of follow-up was a limitation but biomarkers were identified that may be taken forward for clinical utility. In the third workstream, the ELUCIDATE trial registered 1303 patients and randomised 878 patients out of a target of 1000. The trial started late and recruited slowly initially but ultimately recruited with good statistical power to answer the key questions. ELF monitoring altered the patient process of care and may show benefits from the early introduction of interventions with further follow-up. The ELUCIDATE trial was an ‘exemplar’ trial that has demonstrated the challenges of evaluating biomarker strategies in ‘end-to-end’ RCTs and will inform future study designs.

Conclusions

The limitations in the programme were principally that, during the collection and curation of the cohorts of patients with RCC and RT, the pace of discovery of new biomarkers in commercial and non-commercial research was slower than anticipated and so conclusive evaluations using the cohorts are few; however, access to the cohorts will be sustained for future new biomarkers. The ELUCIDATE trial was slow to start and recruit to, with a late surge of recruitment, and so final conclusions about the impact of the ELF test on long-term outcomes await further follow-up. The findings from the three workstreams were used to synthesise a strategy and framework for future biomarker evaluations incorporating innovations in study design, health economics and health informatics.

Trial registration

Current Controlled Trials ISRCTN74815110, UKCRN ID 9954 and UKCRN ID 11930.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 3. See the NIHR Journals Library website for further project information.

Follistatin-like protein 1 plays a tumor suppressor role in clear-cell renal cell carcinoma

BACKGROUND

We previously showed that the expression of follistatin-like protein 1 (FSTL1) was significantly down-regulated in metastatic clear-cell renal cell carcinoma (ccRCC). In this study, we aimed to characterize the role of FSTL1 in the development of ccRCC.

METHODS

The effects of FSTL1 on cell activity and cell cycle were investigated in ccRCC cell lines with altered FSTL1 expression. Gene expression microarray assays were performed to identify the major signaling pathways affected by FSTL1 knockdown. The expression of FSTL1 in ccRCC and its effect on postoperative prognosis were estimated in a cohort with 89 patients.

RESULTS

FSTL1 knockdown promoted anchorage-independent growth, migration, invasion, and cell cycle of ccRCC cell lines, whereas FSTL1 overexpression attenuated cell migration. FSTL1 knockdown up-regulated nuclear factor-κB (NF-κB) and hypoxia-inducible factor (HIF) signaling pathways, increased epithelial-to-mesenchymal transition, up-regulated interleukin-6 expression, and promoted tumor necrosis factor-α-induced degradation of NF-κB inhibitor (IκBα) in ccRCC cell lines. FSTL1 immunostaining was selectively positive in epithelial cytoplasm in the loop of Henle, and positive rate of FSTL1 was significantly lower in ccRCC tissues than in adjacent renal tissues (P < 0.001). The multivariate Cox regression analysis showed that the intratumoral FSTL1 expression conferred a favorable independent prognosis with a hazard ratio of 0.325 (95% confidence interval 0.118-0.894). HIF-2α expression was negatively correlated with FSTL1 expression in ccRCC specimens (r = - 0.229, P = 0.044). Intratumoral expression of HIF-2α, rather than HIF-1α, significantly predicted an unfavorable prognosis in ccRCC (log-rank, P = 0.038).

CONCLUSIONS

FSTL1 plays a tumor suppression role possibly via repressing the NF-κB and HIF-2α signaling pathways. To increase FSTL1 expression might be a candidate therapeutic strategy for metastatic ccRCC.

Preoperative serum cystatin-C as a potential biomarker for prognosis of renal cell carcinoma

PURPOSE

The prognostic value of serum cystatin-C (Cys-C) in renal cell carcinoma (RCC) remains unknown. The purpose of this study is to explore the prognostic value of Cys-C for RCC patients.

PATIENTS AND METHODS

The levels of preoperative Cys-C, creatinine (CRE) and estimated glomerular filtration rate (e-GFR) were retrospectively collected in 325 RCC patients undergoing surgery. The cutoff values of Cys-C, CRE and e-GFR were determined by the standardized Cutoff Finder algorithm. The receiver operating characteristic (ROC) curve and pairwise comparison were performed to compare the three variables. Univariate and multivariate Cox regression analyses were performed to investigate the prognostic value of serum Cys-C in RCC.

RESULTS

Based on the analysis of Cutoff Finder algorithm, ROC curve and pairwise comparison, the preoperative Cys-C was superior to CRE and e-GFR as a predictive factor in RCC. Multivariate Cox regression analyses showed that high preoperative Cys-C (>1.09 mg/L) was significantly associated with shorter overall survival (OS) in all RCC patients (hazard ratio [HR], 1.59; P = 0.012), patients at pT1-2 (P<0.001), pN0 (P<0.001) and pM0 stages (P<0.001). Moreover, Multivariate Cox regression analyses also showed that in the 306 patients without metastasis, high preoperative Cys-C was also associated with shorter disease-free survival (DFS) (HR, 3.50; P = 0.013).

CONCLUSIONS

An elevated preoperative Cys-C level was demonstrated to be related with worse survival in patients with RCC. Measuring preoperative serum Cys-C might be a simple way for finding poor prognostic patients and patients with elevated preoperative Cys-C level should be more closely followed up.

Molecular Dynamics Simulations of Ligand-Induced Flap Conformational Changes in Cathepsin-D-A Comparative Study

The flap region in aspartic proteases is a unique structural feature to this class of enzymes, and found to have a profound impact on protein overall structure, function, and dynamics. Understanding the structure and dynamic behavior of the flap regions is crucial in the design of selective inhibitors against aspartic proteases. Cathepsin-D, an aspartic protease enzyme, has been implicated in a long list of degenerative diseases as well as breast cancer progression. Presented herein, for the first time, is a comprehensive description of the conformational flap dynamics of cathepsin-D using a comparative 50 ns "multiple" molecular dynamics simulations. Diverse collective metrics were proposed to accurately define flap dynamics. These are distance d1 between the flap tips residues (Gly79 and Met301); dihedral angle ϕ; in addition to TriCα angles Gly79-Asp33-Asp223, θ1 , and Gly79-Asp223-Met301, θ2 . The maximum distance attained throughout the simulation was 17.42 and 11.47 Å for apo and bound cathepsin-D, respectively, while the minimum distance observed was 8.75 and 6.32 Å for apo and bound cathepsin-D, respectively. The movement of the flap as well as the twist of the active pocket can properly be explained by measuring the angle, θ1 , between Gly79-Asp33-Met301 and correlating it with the distance Cα of the flap tip residues. The asymmetrical opening of the binding cavity was best described by the large shift of -6.26° to +20.94° in the dihedral angle, ϕ, corresponding to the full opening of the flap at a range of 31-33 ns. A wide-range of post-dynamic analyses was also applied in this report to supplement our findings. We believe that this report would augment current efforts in designing potent structure-based inhibitors against cathepsin-D in the treatment of breast cancer and other degenerative diseases. J. Cell. Biochem. 117: 2643-2657, 2016. © 2016 Wiley Periodicals, Inc.

The urinary proteome and peptidome of renal cell carcinoma patients: a comparison of different techniques

Renal cell carcinomas, originating from the renal cortex, account for about 80% of kidney primary malignancies. Small localized tumors rarely produce symptoms and diagnosis is often delayed until the disease is advanced. In contrast to other urological cancers, renal cell carcinomas are associated with a high degree of metastases and a low 5-year survival rate. The identification of diagnostic and prognostic markers, especially in the urine, remains an area of intense investigation. Different proteomic strategies have been applied so far to biomarker discovery in urine at the proteome or the peptidome level. Gel-based and gel-free strategies combined with mass spectrometry are the most-used strategies, have different success rates, and will be depicted here. We also prefigure a scenario in which the limitations of a single approach are overcome by applying new and complementary research strategies, relying on the excellent availability coupled to the intrinsic richness typical of urine samples.

The endothelial lipase protein is promising urinary biomarker for diagnosis of gastric cancer

Background

Gastric cancer is one of the most common malignant tumors in the world. Finding effective diagnostic biomarkers in urine or serum would represent the most ideal solution to detecting gastric cancer during annual physical examination. This study was to evaluate the potential of endothelial lipase (EL) as a urinary biomarker for diagnosis of gastric cancer.

Methods

The expression levels of EL was measured using Western blotting and immunohistochemical staining experiments on (tissue, serum, and urine) samples of gastric cancer patients versus healthy people. We also checked the EL levels in the urine samples of other cancer types (lung, colon and rectum cancers) and benign lesions (gastritis and gastric leiomyoma) to check if EL was specific to gastric cancer.

Result

We observed a clear separation between the EL expression levels in the urine samples of 90 gastric cancer patients and of 57 healthy volunteers. It was approximately 9.9 fold average decrease of the EL expression levels in the urine samples of gastric cancer compared to the healthy controls (P <0.0001), achieving a 0.967 AUC value for the ROC (receiver operating characteristic) curve, demonstrating it’s highly accurate as a diagnostic marker for gastric cancer. Interestingly, the expression levels of EL in tissue and serum samples were not nearly as discriminative as in urine samples (P = 0.90 and P = 0.79). In immunohistochemical experiments, positive expression of the EL protein was found in 67% (8/12) of gastric adjacent noncancerous and in 58% (7/12) of gastric cancer samples. There was no significant statistical in the expression levels of this protein between the gastric cancer and the matching noncancerous tissues (P =0.67).

Conclusions

The urinary EL as a highly accurate gastric cancer biomarker that is potentially applicable to the general screening with high sensitivity and specificity.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4527331618757552

Proteomic studies of urinary biomarkers for prostate, bladder and kidney cancers

Urine is an ideal body fluid for the detection of protein markers produced by urological cancers as it can be sampled noninvasively and contains secreted and directly shed proteins from the prostate, bladder and kidney. Major challenges of working with urine include high inter-individual and intra-individual variability, low protein concentration, the presence of salts and the dynamic range of protein expression. Despite these challenges, significant progress is being made using modern proteomic methods to identify and characterize protein-based markers for urological cancers. The development of robust, easy-to-use clinical tests based on novel biomarkers has the potential to impact upon diagnosis, prognosis and monitoring and could revolutionize the treatment and management of these cancers.

Sieving through the cancer secretome

Cancer is among the most prevalent and serious health problems worldwide. Therefore, there is an urgent need for novel cancer biomarkers with high sensitivity and specificity for early detection and management of the disease. The cancer secretome, encompassing all the proteins that are secreted by cancer cells, is a promising source of biomarkers as the secreted proteins are most likely to enter the blood circulation. Moreover, since secreted proteins are responsible for signaling and communication with the tumor microenvironment, studying the cancer secretome would further the understanding of cancer biology. Latest developments in proteomics technologies have significantly advanced the study of the cancer secretome. In this review, we will present an overview of the secretome sample preparation process and summarize the data from recent secretome studies of six common cancers with high mortality (breast, colorectal, gastric, liver, lung and prostate cancers). In particular, we will focus on the various platforms that were employed and discuss the clinical applicability of the key findings in these studies. This article is part of a Special Issue entitled: An Updated Secretome.

Improving the accuracy of pre-operative survival prediction in renal cell carcinoma with C-reactive protein

Background:

Validated objective biomarkers are needed for patients with renal cell carcinoma (RCC) to guide patient management and define high-risk populations for follow-up or for therapeutic purposes.

Methods:

Patients undergoing nephrectomy for RCC (n=286 all stages, 84% with conventional clear cell type) were included with a median duration follow-up of 5 years. The prognostic significance of pre-operative haematological and biochemical variables, including C-reactive protein (CRP) values were examined and whether they added additional information to a recently published pre-operative scoring system was determined.

Results:

C-reactive protein was the most significant predictor of overall survival (OS; χ²=50.9, P<0.001). Five-year OS for patients with CRP⩽15 mg l⁻¹vs >15 mg l⁻¹ was 72% (95% CI 65–78%) and 33% (95% CI 23–44%), respectively. Similar results were seen for cancer-specific survival (CSS) and disease-free survival. On multivariate analysis, CRP remained highly significant for CSS (χ²=17.3, P<0.0001) and OS (χ²=9.8, P<0.002), in addition to other pre-operative variables including log of neutrophil/lymphocyte ratio, red blood cell count and white cell count. C-reactive protein was significant in addition to the pre-operative nomogram score (χ²=12.5, P=0.0004 for OS, χ²=16.2, P=0.0001 for CSS and χ²=8.6, P=0.003 for DFS) and was still significant when other pre-operative variables were included.

Conclusion:

C-reactive protein and other haematological and biochemical variables have independent prognostic significance in RCC and may enhance pre-operative scoring systems.

Urinary proteomics--a tool for biomarker discovery

The strong need for the discovery of novel disease markers together with the development of high-throughput techniques that provide highly sensitive analysis of protein content in tissues and bodily fluids, using proteomics, has opened the completely new chapter in biomarker discovery. The detection of biomarkers based on urinary proteome analysis is rapidly advancing and may provide new tools to improve non-invasive diagnostics, prognostics, and therapy enhancement. As a tool for biomarker discovery, urinary proteomics is especially fruitful in the area of early diagnostics and differentiation of renal damage, and it possesses enormous potential for improving and expanding non-invasive cancer diagnostics. An abundance of urinary proteins could provide a wide variety of biomarkers for the diagnosis and follow-up of many systemic diseases as well. This article reviews the utility of urinary proteomics for biomarker discovery from the perspective of clinical application. Despite huge potential and prompt development of urinary proteomics, many challenges are still in front of us. Research effort and financial investment have to be oriented on providing strategies for exceeding current methodological and technical obstacles in a way to ensure the successful validation and implementation of newly discovered urinary biomarkers. The result is expected to be the development of new non-invasive tests and procedures able to guarantee higher efficiency of patient care and provide needed personalized medical approach.

Urine collection and processing for protein biomarker discovery and quantification

BACKGROUND

Urine is a useful source of protein for biomarker discovery and assessment because it is readily available, can be obtained by noninvasive collection methods, and enables monitoring of a wide range of physiologic processes and diseases. Urine aliquots provide enough protein for multiple analyses, combining current protocols with new techniques.

CONCLUSIONS

Standardized collection and processing protocols are now being established and new methods for protein detection and quantification are emerging to complement traditional immunoassays. The current state of urine collection, specimen processing, and storage is reviewed with regard to discovery and quantification of protein biomarkers for cancer.