Enzymes and related proteins as cancer biomarkers: a proteomic approach

BACKGROUND: The discovery of cancer biomarkers has become a major focus of cancer research, which holds promising future for early detection, diagnosis, monitoring disease recurrence and therapeutic treatment efficacy to improve long-term survival of cancer patients. Most of the functional information of the cancer-associated genes resides in the proteome. Since cancer is a complex disease, it might require a panel of multiple biomarkers in order to achieve sufficient clinical efficacy. METHODS: Serum/plasma is the most accessible biological specimen collected from patients. Therefore, serum proteomic diagnostics would be the most promising new test for cancer. With the advent of new and improved proteomic technologies, such as protein chips and mass spectrometry coupled with advanced bioinformatic tools, it is possible to develop potential cancer biomarkers. However, specimen collection, handling, study design and data analysis are essential components for successful biomarker discovery and validation. Multi-center case control study should be conducted with extensive clinical validation to minimize the impact of possible confounding variables (non-biological). CONCLUSIONS: Enzymes and related proteins, such as inhibitors, are promising candidates for cancer diagnostics.     

Plasma circular RNA panel acts as a novel diagnostic biomarker for colorectal cancer

BackgroundColorectal cancer (CRC) is one of the most common cancers worldwide, and emerging lines of evidence have implicated circular RNAs (circRNAs), a novel class of endogenous noncoding RNAs, in CRC development. However, whether plasma circRNAs might be novel diagnostic biomarkers for CRC remains unclear.MethodsWe investigated the plasma levels of selected circRNAs by quantitative real-time PCR (qRT-PCR). The presence of the candidate circRNAs was confirmed through RNase R assays, qRT-PCR and DNA sequencing, and their diagnostic value was evaluated using a receiver operating characteristic (ROC) curve.ResultsThe plasma levels of three circRNAs (circ-CCDC66, circ-ABCC1 and circ-STIL) were significantly decreased in CRC patients (n = 45) compared with healthy controls (n = 61). The ROC curve analysis showed that the area under the ROC curve (AUC) of the three-circRNA panel was 0.780, which is higher than that of traditional protein biomarkers, such as carcinoembryonic antigen (CEA) and carbohydrate antigen 19–9 (CA19-9). Combining the circRNA panel with CEA and CA19-9 might improve the ability to diagnose CRC (AUC = 0.855). In addition, the plasma circ-ABCC1 level was related to tumor growth and progression, and the plasma circ-CCDC66 and circ-ABCC1 levels were decreased in precursor lesions of CRC, including colon adenomas and adenomatous polyps. More importantly, circ-CCDC66 and circ-STIL were found to be useful for diagnosing early-stage CRC, and the three-circRNA panel improved the ability to diagnose CEA-negative and CA19-9-negative CRC.ConclusionOur study provides the first identification of a panel of three plasma circRNAs that could serve as a novel and independent diagnostic biomarker for CRC.     

血浆环状RNA_0002867对HBV相关性肝癌诊断价值的初步研究

目的 探讨血浆环状RNA_0002867（circ_0002867）对HBV相关性肝细胞癌（肝癌）的诊断价值。 方法 分析已发表的测序结果,筛选在肝癌患者的组织和血浆中同时高表达的环状RNA,通过微滴数字PCR（ddPCR）检测35例HBV相关性肝癌患者（肝癌组）及30例HBV相关性肝硬化患者（肝硬化组）血浆circ_0002867表达水平,电化学发光法检测2组患者的血清甲胎蛋白水平,应用受试者工作特征（ROC）曲线分析血浆circ_0002867、血清甲胎蛋白及两者联合对HBV相关性肝癌的诊断价值。 结果 在肝癌患者的组织和血浆中同时高表达的环状RNA中取交集筛选出circ_0002867行进一步验证。肝癌组血浆circ_0002867表达水平为（29.63±11.56）copies/ml,高于肝硬化组的（19.15±11.57）copies/ml（P < 0.001）;血浆circ_0002867、血清甲胎蛋白及两者联合诊断HBV相关性肝癌的ROC曲线下面积分别为0.725（95% CI 0.600~0.828）、0.670 （95% CI 0.542~0.781）、0.810（95%CI 0.693~0.896）,血浆circ_0002867和血清甲胎蛋白两者联合提高了血清甲胎蛋白诊断HBV相关性肝癌的效能（P < 0.05）。 结论 血浆circ_0002867联合血清甲胎蛋白对诊断HBV相关性肝癌具有较好的临床价值。     

Plasma circular RNA hsa_circ_0001821 acts as a novel diagnostic biomarker for malignant tumors

BackgroundCircular RNAs (circRNAs) can function as key regulators of oncogenic processes. The main purpose of this study was to evaluate the expression of hsa_circ_0001821 in plasma of patients with colorectal cancer (CRC) and other malignant tumors and analyze its correlations with clinical features and diagnostic values.MethodsIn total, 467 plasma samples, including samples from 80 healthy controls, were collected between 2015 and 2019 from patients at the Affiliated People''s Hospital of Ningbo University. Plasma levels of hsa_circ_0001821 were analyzed by qRT‐PCR. The diagnostic value was performed using receiver operating characteristic (ROC) curve.ResultsPlasma hsa_circ_0001821 was increased in CRC patients, and high hsa_circ_0001821 expression predicted advanced stage and unfavorable in overall survival. In addition, this study showed the upregulation of hsa_circ_0001821 in plasma of lung cancer and hepatocellular carcinoma (HCC). ROC curve showed that the region under the loop for the diagnosis of CRC, HCC, and lung cancer was 0.815, 0.692, and 0.792.ConclusionPlasma hsa_circ_0001821 possibly is a novel biological marker for malignant tumors.     

Ischemia-modified albumin as an oxidative stress biomarker in obesity

Objective

We evaluated the levels of ischemia-modified albumin (IMA) and its association with body mass index (BMI) in patients who are obese.

Design and methods

Fasting glucose, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, malondialdehyde, and IMA levels were assessed in 148 subjects.

Results

IMA, malondialdehyde, and fasting glucose levels were significantly higher while the HDL cholesterol levels were lower in obese population.

Conclusions

IMA levels increase in overweight and obese subjects.     

Amyloid P component as a plasma marker for Parkinson's disease identified by a proteomic approach

ObjectivesParkinson's disease (PD) ranks the second among the neurodegenerative disorders. Proteins involved in Parkinson's disease (PD) have been investigated but none as the diagnostic markers in blood.Design and methodsIn this study, we applied a proteomic strategy, by utilizing two-dimensional electrophoresis and mass spectrometry, to analyze two sample pools of plasma from the healthy individuals and PD subjects.ResultsIgGκL and human serum amyloid P component (SAP) were found differentially expressed between these pools. SAP level increased by approximately 5-fold in PD samples, and the ELISA procedure revealed a significant (P < 0.001) increase in SAP concentration (65.9 ± 18.7 μg/mL) in the plasma of PD subjects (healthy individuals, 35.0 ± 12.5 μg/mL), with sensitivity of 94.1% and specificity of 87.5%.ConclusionOur results indicated a potential feasibility of plasma SAP as a marker to approach PD.     

Time course proteomic profiling of human myocardial infarction plasma samples: an approach to new biomarker discovery

BackgroundThe aim of this study was to identify novel candidate biomarker proteins differentially expressed in the plasma of patients with early stage acute myocardial infarction (AMI) using SELDI-TOF-MS as a high throughput screening technology.MethodsTen individuals with recent acute ischemic-type chest pain (< 12 h duration) and ST-segment elevation AMI (1STEMI) and after a second AMI (2STEMI) were selected. Blood samples were drawn at six times after STEMI diagnosis. The first stage (T₀) was in Emergency Unit before receiving any medication, the second was just after primary angioplasty (T₂), and the next four stages occurred at 12 h intervals after T₀. Individuals (n = 7) with similar risk factors for cardiovascular disease and normal ergometric test were selected as a control group (CG). Plasma proteomic profiling analysis was performed using the top-down (i.e. intact proteins) SELDI-TOF-MS, after processing in a Multiple Affinity Removal Spin Cartridge System (Agilent).ResultsCompared with the CG, the 1STEMI group exhibited 510 differentially expressed protein peaks in the first 48 h after the AMI (p < 0.05). The 2STEMI group, had ~ 85% fewer differently expressed protein peaks than those without previous history of AMI (76, p < 0.05). Among the 16 differentially-regulated protein peaks common to both STEMI cohorts (compared with the CG at T₀), 6 peaks were persistently down-regulated at more than one time-stage, and also were inversed correlated with serum protein markers (cTnI, CK and CKMB) during 48 h-period after IAM.ConclusionsProteomic analysis by SELDI-TOF-MS technology combined with bioinformatics tools demonstrated differential expression during a 48 h time course suggests a potential role of some of these proteins as biomarkers for the very early stages of AMI, as well as for monitoring early cardiac ischemic recovery.     

Identification and confirmation of haptoglobin as a potential serum biomarker in hypertrophic cardiomyopathy using proteomic approaches

Abstract

Introduction. Aiming at identifying biomarkers for hypertrophic cardiomyopathy (HCM), the serum proteome was explored through a two-dimensional gel-based proteomic approach (2D-DIGE) coupled with mass spectrometry and database interrogation.

Methods. Serum samples from 20 male HCM patients and their sex- and age-matched controls were cleaned from interfering components. Patients and controls were pooled in five matched groups with the same age, and proteins extracts from each pool were labelled with cyanine dyes. Then, gel images were analysed using a fluorescence scanner and proteins were identified. Tryptic peptides were analysed by capillary reversed-phase liquid chromatography coupled online with tandem mass spectrometry (MS/MS).

Results. Four different proteins were observed to be differentially expressed between HCM patients and their matched controls. Of them, decreases in haptoglobin levels were confirmed to be associated with HCM in an independent set of 181 consecutive HCM patients from our monographic clinic and 114 controls with similar age and sex using a nephelometer-based technique. Moreover, a significant negative correlation was observed between haptoglobin and subaortic gradient, thus highlighting the role of haptoglobin in HCM.

Conclusion. All these observations point out the utility of the 2D-DIGE proteomic strategy for the identification of serum proteins indicative of the presence of cardiac injury.     

Interpretation of large-scale quantitative shotgun proteomic profiles for biomarker discovery

Large-scale quantitative shotgun tandem mass spectrometry serves as a flexible proteomic platform for the systematic investigation of molecular processes perturbed by disease and the potential discovery of clinically relevant protein biomarkers associated with a particular pathology. Multiple innovative profiling techniques have been introduced with the aims of comprehensively identifying and quantifying the protein complements of human tissues and blood and enabling the systematic comparison of clinically relevant specimens. In this review, the novel computational methods that have been developed to maximize the amount of information inferred from the raw spectral datasets are explored, including innovative database search programs for more complete and confident protein identifications, improved normalization and data processing techniques to enhance statistical accuracy, and innovative algorithms for improved pattern discrimination and biomarker candidate ranking. Ultimately, integrative biomarker analyses that amalgamate the protein expression data generated by these approaches, together with data from high-throughput functional genomics, offer the possibility of identifying the mechanisms and causative factors that underlie complex human diseases, thereby improving both clinical outcomes and personalized treatment options.     

The experimental autoimmune encephalomyelitis model for proteomic biomarker studies: from rat to human

Multiple sclerosis (MScl) is defined by central nervous system (CNS) inflammation, demyelination and axonal damage. Some of the disease mechanisms are known but the cause of this complex disorder stays an enigma. Experimental autoimmune encephalomyelitis (EAE) is an animal model mimicking many aspects of MScl. This review aims to provide an overview over proteomic biomarker studies in the EAE model emphasizing the translational aspects with respect to MScl in humans.     

Childhood obesity: a transtheoretical case management approach

Childhood obesity is an increasing health problem because of its strong associations with chronic health problems in children and adults. Obesity during childhood commonly persists into adulthood and is resistant to interventions that involve only recommendations to decrease caloric intake and to increase caloric expenditure through increased physical activity. The challenge with this approach to childhood obesity is that it is not theoretically based, nor does it consider the child's or the parent's perceptions of the health problem or their transition along the stages of behavioral change. Case management has been proven to be successful in managing various chronic health problems in both adults and children. This article will introduce a new intervention model based on the transtheoretical framework by utilizing case management in a primary care setting to treat childhood obesity.     

Lipocalin-2 as a biomarker for diabetic nephropathy

Diabetes is a major global public health issue. The prevalence of type 1 diabetes is comparatively static, as hereditary and genetic causes are involved, while type 2 diabetes (T2D) prevalence is increasing day by day. T2D is associated with chronic complications, including diabetic neuropathy (DN), nephropathy, retinopathy, and other complications like diabetic foot. DN is the main complication of both types of diabetes. DN can be diagnosed by routine laboratory tests, microalbuminuria > 300 mg/24 h, and a gradual decrease in glomerular filtration rate. As the appearance of microalbuminuria is a late manifestation, an early marker for renal damage is needed. Lipocalin-2, also known as neutrophil gelatinase-associated lipocalin (NGAL), is a small protein purified from neutrophil granules and a good marker for kidney disease. NGAL is a transporter protein responsible for many physiological processes, such as inflammation, generation of the immune response, and metabolic homeostasis. NGAL has been reported to depict the early changes in renal damage when urine microalbumin is still undetecable. Therefore, elucidating the role of NGAL in detecting DN and understanding its mechanism can help establish it as a potential early marker for DN.     

Plasma neutrophil gelatinase-associated lipocalin as a predictive biomarker for the detection of acute kidney injury in adult poisoning

Context: Acute kidney injury (AKI) is a serious complication in intoxicated patients. Recently, a new biomarker - neutrophil gelatinase-associated lipocalin (NGAL) - was used to predict AKI in patients who were critically ill or had sepsis. Objective: To evaluate the utility of plasma NGAL as an early predictor of AKI in adults with acute poisoning. Materials and methods: This retrospective, observational, cohort study was conducted between December 2013 and November 2014. A total of 157 consecutive adult patients who presented to the emergency department (Level 1 regional center) of Kyungpook National University Hospital, a tertiary teaching hospital in Daegu, Korea, within 24 h of poisoning were included. Initial plasma NGAL levels and laboratory parameters were concurrently measured upon hospital arrival. AKI was defined according to Acute Kidney Injury Network criteria. Development of AKI was predicted using plasma NGAL levels and by analyzing the area under the receiver operating characteristic curve (AUC). Results: The overall rate of AKI was 14.6% (n?=?23). Plasma NGAL levels in the AKI group were higher than those in the non-AKI group (median, 310 vs. 86 ng/mL; p?<0.001). Additionally, baseline NGAL levels allowed for better prediction of AKI than initial creatinine levels. The AUC of plasma NGAL was 0.895 (95% confidence interval [CI]: 0.832–0.941), with a cut-off value of 227 ng/mL (sensitivity, 76.2%; specificity, 95.8%). Plasma NGAL had a higher predictive capacity for AKI than serum creatinine (AUC 0.741, 95% CI: 0.662–0.810), base deficit (AUC 0.795, 95% CI: 0.701–0.870), lactate (AUC 0.781, 95% CI: 0.690–0.856), and anion gap (AUC 0.636, 95% CI: 0.535–0.730). Conclusion: Plasma NGAL may serve as a good predictor of AKI in cases of adult poisoning.     

Plasma neutrophil gelatinase-associated lipocalin as a biomarker for acute kidney injury in critically ill patients with suspected sepsis

Objectives

The aim of this study was to investigate the diagnostic utility of plasma neutrophil gelatinase-associated lipocalin (NGAL) as an early objective biomarker to predict acute kidney injury (AKI) in critically ill patients with suspected sepsis, for whom procalcitonin (PCT) was used for the diagnosis and staging of sepsis.

Design and methods

Plasma NGAL was measured using the Triage NGAL Test (Alere, Inc., San Diego, CA, USA) in 231 samples obtained from patients with suspected sepsis. The results of NGAL were compared with those of Elecsys BRAHMS PCT (Roche Diagnostics, Basel, Switzerland). Renal failure was assessed using the renal subscore of Sepsis-related Organ Failure Assessment (SOFA) score. AKI was defined according to the Acute Kidney Injury Network criteria.

Results

The concentrations of plasma NGAL were significantly different according to the five groups of PCT concentration (P < 0.0001) and the renal subscore of SOFA score (P < 0.0001). Plasma NGAL was significantly increased in the patients with AKI compared with those without AKI (416.5 ng/mL vs. 181.0 ng/mL, P = 0.0223).

Conclusion

Plasma NGAL seems to be a highly sensitive and objective predictor of AKI in patients with sepsis. Plasma NGAL can be added for the diagnosis and staging of renal failure in sepsis.     

Alzheimer's disease cerebrospinal fluid biomarker discovery: a proteomics approach

There is significant interest in the identification of effective biomarkers for Alzheimer's disease. Such biomarkers could aid in the clinical diagnosis of the disease and may be useful in assessing the efficacy of various treatment strategies. The search for biomarkers often includes the analysis of changes in cerebrospinal fluid protein expression that correlate with disease. These changes can be measured using a variety of technologies for protein expression profiling. Although there is great promise in the application of these methods to biomarker discovery based on some preliminary observations, there are significant issues in the capabilities of most of these technologies that have limited their effective application. The most recent literature involving proteomic discovery of new cerebrospinal fluid biomarkers for Alzheimer's disease is reviewed.