Altered plasma apolipoprotein modifications in patients with pancreatic cancer: protein characterization and multi-institutional validation

Genotypes of carboxypeptidase A1 and gamma-glutamyltransferase 1 may be useful tools for the diagnosis and the predictor of worrisome features of intraductal papillary mucinous neoplasm in Japan

Background and Aim

This study aimed to clarify whether several single-nucleotide polymorphisms (SNPs)-related chronic pancreatitis such as carboxypeptidase A1 (CPA1), carboxypeptidase B1 (CPB1), Gamma-glutamyltransferase 1 (GGT1), G-protein-coupled receptor Class C Group 6 Member A (GPRC6A), and serine protease inhibitor, Kazal type 1 (SPINK-1) genotypes were associated with clinical characteristics of patients with intraductal papillary mucinous neoplasm (IPMN) and worrisome features of IPMN.

Methods

We enrolled 100 patients with IPMN and 116 patients as a control. Serum p-amylase, lipase, trypsin, phospholipase A2 (PLA2), and elastase-1 levels were measured. An Olympus EUS (GF-UCT 260) was used to perform endosonography in 100 patients with IPMN. Total EUS score was evaluated using endosonography. DNA was isolated from the duodenal tissue using a commercial system and polymerase chain reaction (PCR) was performed on 7500 Fast PCR System.

Results

There were no associations between glucose tolerances, lipid levels and genotypes of CPA1, GGT1, GPRC6A, and SPINK-1 in patients with IPMN. CPA1 genotype was significantly associated with the pathophysiology of IPMN. Then, GGT1 genotype was also significantly associated with EUS total score and the size of cyst more than 20 mm and more than 30 mm as one of worrisome features of IPMN.

Conclusion

Genotypes of carboxypeptidase A1 and gamma-glutamyltransferase 1 may be useful tools for the diagnosis and the predictor of worrisome features of IPMN.

Potential of Carbohydrate Antigen 19-9 and Serum Apolipoprotein A2-Isoforms in the Diagnosis of Stage 0 and IA Pancreatic Cancer

Apolipoprotein A2-ATQ/AT (apoA2-ATQ/AT) is a new biomarker for diagnosing pancreatic cancer (PC). In this study, the value of blood carbohydrate antigen 19-9 (CA19-9) and apoA2-ATQ/AT levels in diagnosing stage 0 and IA PC was evaluated. During 2014-2021, 12 patients with stage 0 PC and 12 patients with IA PC (average age: 73.8 years) underwent resection at JA Onomichi General Hospital. In addition, the data of 200 healthy controls were collected from a community-based cohort study. Levels of two apoA2-isoforms were measured using enzyme-linked immunosorbent assay (ELISA) with specific antibodies to calculate the apoA2-i Index as a surrogate value for apoA2-ATQ/AT. The cutoff value for the apoA2-i Index was determined to be 62.9 μg/mL. CA19-9 levels were also measured through ELISA. Among all 24 patients with PC, the positivity rates for apoA2-i and CA19-9 were 33.3% and 25.0%, respectively. The positivity rates for apoA2-i and CA19-9 were 16.7% and 8.3% in patients with stage 0 PC and 50.0% and 41.7% in those with stage IA, respectively. For CA19-9-negative patients, the apoA2-i positivity rate was 9.1% in stage 0 and 42.9% in stage IA. The combined positivity rate for both markers was 16.7% in stage 0 and 66.7% in stage IA. Imaging findings in apoA2-i- and CA19-9-positive patients included pancreatic duct dilatation (87.5%/100%), duct stenosis (75.0%/50%), and atrophy (87.5%/66.7%). The imaging findings of this study suggest that apoA2-i may enhance the sensitivity for detecting CA19-9-negative stage 0 and IA PC, and complementary measurements with CA19-9 may be valuable for diagnosing early-stage PC. Therefore, minute PC with pancreatic duct dilation, duct stenosis, and atrophy may exhibit a high positivity rate, aiding differential diagnosis.

Serum levels of the N-terminal fragment of connective tissue growth factor is a novel biomarker for chronic pancreatitis

Chronic inflammation of the pancreas is considered to be one of the causes of pancreatic cancer. However, the diagnosis of chronic pancreatitis (CP) is very difficult in the pancreas, where biopsies are difficult to perform. The prevalence of CP is estimated to be many times more common than in patients with actual symptomatic CP. In recent years, abnormal cleavage of certain proteins has attracted attention as a biomarker for CP other than pancreatic enzymes. Connective tissue growth factor (CTGF) is one of the growth factors involved in tissue repair and other processes and is increased by stimulation of transforming growth factor-β, suggesting a relationship of CTGF with fibrosis. In this study, we measured the total length of CTGF in blood and N-terminal fragment CTGF in 48 cases of chronic pancreatitis, 64 cases of pancreatic cancer and 45 healthy volunteers (HV). Interestingly, we found that blood N-terminal fragment CTGF level was significantly increased in CP and pancreatic cancer patients. Multiple logistic regression analysis showed serum levels of N-terminal fragment CTGF, CRP and amylase were significant and independent variables for the differential diagnosis of CP from HV. Receiver operating characteristic analysis showed that area under the curve (AUC) value of serum N-terminal fragment CTGF level was 0.933, which can differentiate between CP and HV. Several factors would be involved in the increase in serum N-terminal fragment CTGF level. In conclusion, serum N-terminal fragment CTGF level is a promising new biomarker for CP.

Clinical development of a blood biomarker using apolipoprotein-A2 isoforms for early detection of pancreatic cancer

BACKGROUND

We have previously reported apolipoprotein A2-isoforms (apoA2-is) as candidate plasma biomarkers for early-stage pancreatic cancer. The aim of this study was the clinical development of apoA2-is.

METHODS

We established a new enzyme-linked immunosorbent sandwich assay for apoA2-is under the Japanese medical device Quality Management System requirements and performed in vitro diagnostic tests with prespecified end points using 2732 plasma samples. The clinical equivalence and significance of apoA2-is were compared with CA19-9.

RESULTS

The point estimate of the area under the curve to distinguish between pancreatic cancer (n = 106) and healthy controls (n = 106) was higher for apoA2-ATQ/AT [0.879, 95% confidence interval (CI): 0.832-0.925] than for CA19-9 (0.849, 95% CI 0.793-0.905) and achieved the primary end point. The cutoff apoA2-ATQ/AT of 59.5 μg/mL was defined based on a specificity of 95% in 2000 healthy samples, and the reliability of specificities was confirmed in two independent healthy cohorts as 95.3% (n = 106, 95% CI 89.4-98.0%) and 95.8% (n = 400, 95% CI 93.3-97.3%). The sensitivities of apoA2-ATQ/AT for detecting both stage I (47.4%) and I/II (50%) pancreatic cancers were higher than those of CA19-9 (36.8% and 46.7%, respectively). The combination of apoA2-ATQ/AT (cutoff, 59.5 μg/mL) and CA19-9 (37 U/mL) increased the sensitivity for pancreatic cancer to 87.7% compared with 69.8% for CA19-9 alone. The clinical performance of apoA2-is was blindly confirmed by the National Cancer Institute Early Detection Research Network.

CONCLUSIONS

The clinical performance of ApoA2-ATQ/AT as a blood biomarker is equivalent to or better than that of CA19-9.

Identification of activity-based biomarkers for early-stage pancreatic tumors in blood using single-molecule enzyme activity screening

Single-molecule enzyme activity-based enzyme profiling (SEAP) is a methodology to globally analyze protein functions in living samples at the single-molecule level. It has been previously applied to detect functional alterations in phosphatases and glycosidases. Here, we expand the potential for activity-based biomarker discovery by developing a semi-automated synthesis platform for fluorogenic probes that can detect various peptidases and protease activities at the single-molecule level. The peptidase/protease probes were prepared on the basis of a 7-amino-4-methylcoumarin fluorophore. The introduction of a phosphonic acid to the core scaffold made the probe suitable for use in a microdevice-based assay, while phosphonic acid served as the handle for the affinity separation of the probe using Phos-tag. Using this semi-automated scheme, 48 fluorogenic probes for the single-molecule peptidase/protease activity analysis were prepared. Activity-based screening using blood samples revealed altered single-molecule activity profiles of CD13 and DPP4 in blood samples of patients with early-stage pancreatic tumors. The study shows the power of single-molecule enzyme activity screening to discover biomarkers on the basis of the functional alterations of proteins.

Apolipoprotein A2 isoforms associated with exocrine pancreatic insufficiency in early chronic pancreatitis

BACKGROUND AND AIM

Apolipoprotein A2 (apoA2) isoforms have been reported to undergo the aberrant processing in pancreatic cancer and pancreatic risk populations compared with that in healthy subjects. This study aimed to clarify whether apoA2 isoforms were as useful as N-benzoyl-p-aminobenzoic acid (BT-PABA) test for exocrine pancreatic dysfunction markers in patients with early chronic pancreatitis (ECP).

METHODS

Fifty consecutive patients with functional dyspepsia with pancreatic enzyme abnormalities (FD-P) (n = 18), with ECP (n = 20), and asymptomatic patients with pancreatic enzyme abnormalities (AP-P) (n = 12) based on the Rome IV classification and the Japan Pancreatic Association were enrolled in this study. The enrolled patients were evaluated using endoscopic ultrasonography and endoscopic ultrasonography elastography. Five pancreatic enzymes were estimated. Pancreatic exocrine function was analyzed using the BT-PABA test. Lighter and heavier apoA2 isoforms, AT and ATQ levels were measured by enzyme-linked immunosorbent assay methods.

RESULTS

There were no significant differences in clinical characteristics such as age, gender, body mass index, alcohol consumption and smoking among patients with AP-P, FD-P, and ECP. The BT-PABA test and lighter apoA2 isoform, AT level in the enrolled patients had a significant correlation (P < 0.01). The BT-PABA test in patients with ECP was significantly lower (P = 0.04) than that in AP-P. ApoA2-AT level in patients with ECP was lower than that in AP-P, albeit, insignificantly. Interestingly, apo A2-AT level was significantly (P = 0.041) associated with exocrine pancreatic insufficiency by multiple logistic regression analysis.

CONCLUSIONS

ApoA2-AT level is a useful tool to evaluate exocrine pancreatic insufficiency in the early stage of chronic pancreatitis.

Development of fluorogenic substrates for colorectal tumor-related neuropeptidases for activity-based diagnosis

The M3 metalloproteases, neurolysin and THOP1, are neuropeptidases that are expressed in various tissues and metabolize neuropeptides, such as neurotensin. The biological roles of these enzymes are not well characterized, partially because the chemical tools to analyse their activities are not well developed. Here, we developed a fluorogenic substrate probe for neurolysin and thimet oligopeptidase 1 (THOP1), which enabled the analysis of enzymatic activity changes in tissue and plasma samples. In particular, the probe was useful for studying enzyme activities in a single-molecule enzyme assay platform, which can detect enzyme activity with high sensitivity. We detected the activity of neurolysin in plasma samples and revealed higher enzyme activity in the blood samples of patients with colorectal tumor. The result indicated that single-molecule neurolysin activity is a promising candidate for a blood biomarker for colorectal cancer diagnosis.

Multiplexed Detection of Pancreatic Cancer by Combining a Nanoparticle-Enabled Blood Test and Plasma Levels of Acute-Phase Proteins

Simple Summary

In this study, a multiplexed strategy based on the combination of a nanoparticle-enabled blood test and serum levels of acute-phase proteins proved to be able to distinguish pancreatic cancer patients from healthy controls with a good and sex-dependent prediction ability. This study suggests a possible role of acute-phase proteins as pancreatic cancer biomarkers and paves the way for the development of multiplexed technologies for early cancer detection.

Abstract

The development of new tools for the early detection of pancreatic ductal adenocarcinoma (PDAC) represents an area of intense research. Recently, the concept has emerged that multiplexed detection of different signatures from a single biospecimen (e.g., saliva, blood, etc.) may exhibit better diagnostic capability than single biomarkers. In this work, we develop a multiplexed strategy for detecting PDAC by combining characterization of the nanoparticle (NP)-protein corona, i.e., the protein layer that surrounds NPs upon exposure to biological fluids and circulating levels of plasma proteins belonging to the acute phase protein (APPs) family. As a first step, we developed a nanoparticle-enabled blood (NEB) test that employed 600 nm graphene oxide (GO) nanosheets and human plasma (HP) (5% vol/vol) to produce 75 personalized protein coronas (25 from healthy subjects and 50 from PDAC patients). Isolation and characterization of protein corona patterns by 1-dimensional (1D) SDS-PAGE identified significant differences in the abundance of low-molecular-weight corona proteins (20–30 kDa) between healthy subjects and PDAC patients. Coupling the outcomes of the NEB test with the circulating levels of alpha 2 globulins, we detected PDAC with a global capacity of 83.3%. Notably, a version of the multiplexed detection strategy run on sex-disaggregated data provided substantially better classification accuracy for men (93.1% vs. 77.8%). Nanoliquid chromatography tandem mass spectrometry (nano-LC MS/MS) experiments allowed to correlate PDAC with an altered enrichment of Apolipoprotein A-I, Apolipoprotein D, Complement factor D, Alpha-1-antichymotrypsin and Alpha-1-antitrypsin in the personalized protein corona. Moreover, other significant changes in the protein corona of PDAC patients were found. Overall, the developed multiplexed strategy is a valid tool for PDAC detection and paves the way for the identification of new potential PDAC biomarkers.

Construction of 2DE Patterns of Plasma Proteins: Aspect of Potential Tumor Markers

The use of tumor markers aids in the early detection of cancer recurrence and prognosis. There is a hope that they might also be useful in screening tests for the early detection of cancer. Here, the question of finding ideal tumor markers, which should be sensitive, specific, and reliable, is an acute issue. Human plasma is one of the most popular samples as it is commonly collected in the clinic and provides noninvasive, rapid analysis for any type of disease including cancer. Many efforts have been applied in searching for “ideal” tumor markers, digging very deep into plasma proteomes. The situation in this area can be improved in two ways—by attempting to find an ideal single tumor marker or by generating panels of different markers. In both cases, proteomics certainly plays a major role. There is a line of evidence that the most abundant, so-called “classical plasma proteins”, may be used to generate a tumor biomarker profile. To be comprehensive these profiles should have information not only about protein levels but also proteoform distribution for each protein. Initially, the profile of these proteins in norm should be generated. In our work, we collected bibliographic information about the connection of cancers with levels of “classical plasma proteins”. Additionally, we presented the proteoform profiles (2DE patterns) of these proteins in norm generated by two-dimensional electrophoresis with mass spectrometry and immunodetection. As a next step, similar profiles representing protein perturbations in plasma produced in the case of different cancers will be generated. Additionally, based on this information, different test systems can be developed.

Apolipoprotein A-II, a Player in Multiple Processes and Diseases

Apolipoprotein A-II (apoA-II) is the second most abundant apolipoprotein in high-density lipoprotein (HDL) particles, playing an important role in lipid metabolism. Human and murine apoA-II proteins have dissimilar properties, partially because human apoA-II is dimeric whereas the murine homolog is a monomer, suggesting that the role of apoA-II may be quite different in humans and mice. As a component of HDL, apoA-II influences lipid metabolism, being directly or indirectly involved in vascular diseases. Clinical and epidemiological studies resulted in conflicting findings regarding the proatherogenic or atheroprotective role of apoA-II. Human apoA-II deficiency has little influence on lipoprotein levels with no obvious clinical consequences, while murine apoA-II deficiency causes HDL deficit in mice. In humans, an increased plasma apoA-II concentration causes hypertriglyceridemia and lowers HDL levels. This dyslipidemia leads to glucose intolerance, and the ensuing high blood glucose enhances apoA-II transcription, generating a vicious circle that may cause type 2 diabetes (T2D). ApoA-II is also used as a biomarker in various diseases, such as pancreatic cancer. Herein, we provide a review of the most recent findings regarding the roles of apoA-II and its functions in various physiological processes and disease states, such as cardiovascular disease, cancer, amyloidosis, hepatitis, insulin resistance, obesity, and T2D.

Circulating Proteins Associated with Response and Resistance to Neoadjuvant Chemotherapy in HER2-Positive Breast Cancer

Simple Summary

The goal of this study was to find circulating proteins that can be easily sampled and incorporated into a clinical setting to improve predictive treatment response in HER2-positive breast cancer patients receiving neoadjuvant chemotherapy. We looked for potential biomarkers in serum, which we identified using two proteomics techniques: qualitative LC-MS/MS and a quantitative assay that assessed protein expression between responders and non-responders HER2-positive breast cancer patients to neoadjuvant chemotherapy.

Abstract

Despite the increasing use of neoadjuvant chemotherapy (NAC) in HER2-positive breast cancer (BC) patients, the clinical problem of predicting individual treatment response remains unanswered. Furthermore, the use of ineffective chemotherapeutic regimens should be avoided. Serum biomarker levels are being studied more and more for their ability to predict therapy response and aid in the development of personalized treatment regimens. This study aims to identify effective protein networks and biomarkers to predict response to NAC in HER2-positive BC patients through an exhaustive large-scale LC-MS/MS-based qualitative and quantitative proteomic profiling of serum samples from responders and non-responders. Serum samples from HER2-positive BC patients were collected before NAC and were processed by three methods (with and without nanoparticles). The qualitative analysis revealed differences in the proteomic profiles between responders and non-responders, mainly in proteins implicated in the complement and coagulation cascades and apolipoproteins. Qualitative analysis confirmed that three proteins (AFM, SERPINA1, APOD) were correlated with NAC resistance. In this study, we show that serum biomarker profiles can predict treatment response and outcome in the neoadjuvant setting. If these findings are further developed, they will be of significant clinical utility in the design of treatment regimens for individual BC patients.

Risk stratification of pancreatic cancer by a blood test for apolipoprotein A2-isoforms

Though pancreatic cancer is uncommon, with an age-adjusted annual incidence of 12.9 cases per 100,000 person-years, it is considered a refractory cancer due to the mortality of 11.0 per 100,000 person-years. To efficiently identify patients with potentially surgically-curable pancreatic cancer, high-risk individuals (HRIs) for pancreatic cancer should be identified by easily and minimally invasive methods from the general population. We have identified unique processing patterns in the C-terminal amino acids of apolipoprotein A2 homodimer in the blood of patients with pancreatic cancer and in HRIs, and we called them apoA2-isoforms (apoA2-i). We then established an enzyme-linked immunosorbent assay (ELISA) to measure circulating apoA2-i in the blood stream. The diagnostic accuracy of apoA2-i to distinguish pancreatic cancer HRIs was verified by several retrospective studies, blind testing with the National Cancer Institute (NCI) Early Detection Research Network (EDRN), a prospective study with prediagnostic samples organized by the European Prospective Investigation into Cancer and Nutrition (EPIC) study, and the prospective screening study of pancreatic cancer in Kobe.The apoA2-i blood test is a potential biomarker to identify HRIs and the curative stage of pancreatic cancer in the general population.

Noninvasive risk stratification of intraductal papillary mucinous neoplasia with malignant potential by serum apolipoprotein-A2-isoforms

Intraductal papillary mucinous neoplasms (IPMNs) are premalignant lesions of pancreatic cancer. An accurate serum biomarker, which allows earlier identification of asymptomatic individuals with high-risk for developing cancer, is of urgent need. Apolipoprotein A2-isoforms (apoA2-i) have previously been identified as biomarkers in pancreatic cancer. This study investigates a potential clinical application of the serum apoA2-i for risk stratification of IPMN and associated cancer. The concentrations of apoA2-i were retrospectively determined in 523 patient sera specimen, composed of 305 IPMNs with preinvasive lesions with different grades of dysplasia and invasive cancer, 140 pancreatic ductal adenocarcinoma, 78 with other cystic lesions and healthy controls cohorts, using an apoA2-i enzyme-linked immunosorbent assay kit. The diagnostic performance of serum apoA2-i was assessed and compared to routine clinical marker CA 19-9. ApoA2-i levels were significantly reduced in all IPMN samples regardless of stage compared to healthy controls. Receiver operating characteristic curve analysis of IPMNs with high-grade dysplasia and IPMN with associated carcinoma revealed the area under curve (AUC) of 0.91 and >0.94, respectively. The respective sensitivities were 70% and 83% with a specificity of 95%, and significantly higher than the gold standard biomarker CA 19-9. AUC values of apoA2-i for detecting IPMN-associated carcinoma of colloid and ductal subtypes were 0.990 and 0.885, respectively. ApoA2-i has the potential to early detect the risk of malignancy of patients with IPMN. The serological apoA2-i test in combination with imaging modalities could help improve the diagnosis of IPMN malignancy. Further validation in larger and independent international cohort studies is needed.

[Correlation between Pretreatment Serum Apolipoprotein Level and Prognosis of Small Cell Lung Cancer Patients]

BACKGROUND

Lung cancer is the leading cause of cancer-related death, and small cell lung cancer (SCLC) has a poor prognosis in all types of lung cancer. This study evaluated the relationship between pretreatment serum apolipoprotein levels and prognosis in patients with SCLC, seeks a new index can guide diagnosis and treatment of SCLC.

METHODS

This study retrospectively analyzed the clinical data of 122 patients with SCLC. The clinical results of patients with serum apolipoprotein levels within 2 weeks before treatment were collected, including apolipoprotein AI (ApoA-I), apolipoprotein B (ApoB), and the ratio of apolipoprotein B to apolipoprotein AI (ApoB/ApoA-I). Patients' progression-free survival (PFS) and overall survival (OS) are the main outcome indicators. The best critical to determine the index's value by X-tile tool. For survival analysis, Kaplan-Meier method was used for analysis, and Cox regression analysis method was used for single factor analysis and multifactor analysis.

RESULTS

Compared with patients with low ApoA-I levels, patients with high ApoA-I levels (ApoA-I>1.12 g/L) had better OS (21.5 mon vs 12.3 mon, P=0.007) and PFS (7.3 mon vs 5.5 mon, P=0.017). In contrast, patients with higher ApoB/ApoA-I levels had worse median OS than patients with lower ApoB/ApoA-I levels (13.4 mon vs 20.7 mon, P=0.012). Multivariate Cox regression analysis showed that ApoA-I was an independent prognostic factor affecting PFS in SCLC patients (HR=0.67, 95%CI: 0.45-0.99, P=0.043). ApoB/ApoA-I is an independent risk factor for OS in patients with SCLC (HR=1.98, 95%CI: 1.21-3.23, P=0.007).

CONCLUSIONS

Serum ApoA-I level and ApoB/ApoA-I level before treatment can be important prognostic factors for SCLC, which is helpful to judge the prognosis of patients.

Proteomics, Personalized Medicine and Cancer

As of 2020 the human genome and proteome are both at >90% completion based on high stringency analyses. This has been largely achieved by major technological advances over the last 20 years and has enlarged our understanding of human health and disease, including cancer, and is supporting the current trend towards personalized/precision medicine. This is due to improved screening, novel therapeutic approaches and an increased understanding of underlying cancer biology. However, cancer is a complex, heterogeneous disease modulated by genetic, molecular, cellular, tissue, population, environmental and socioeconomic factors, which evolve with time. In spite of recent advances in treatment that have resulted in improved patient outcomes, prognosis is still poor for many patients with certain cancers (e.g., mesothelioma, pancreatic and brain cancer) with a high death rate associated with late diagnosis. In this review we overview key hallmarks of cancer (e.g., autophagy, the role of redox signaling), current unmet clinical needs, the requirement for sensitive and specific biomarkers for early detection, surveillance, prognosis and drug monitoring, the role of the microbiome and the goals of personalized/precision medicine, discussing how emerging omics technologies can further inform on these areas. Exemplars from recent onco-proteogenomic-related publications will be given. Finally, we will address future perspectives, not only from the standpoint of perceived advances in treatment, but also from the hurdles that have to be overcome.

Multi-Omic Biomarkers as Potential Tools for the Characterisation of Pancreatic Cystic Lesions and Cancer: Innovative Patient Data Integration

Pancreatic cancer (PC) is regarded as one of the most lethal malignant diseases in the world, with GLOBOCAN 2020 estimates indicating that PC was responsible for almost half a million deaths worldwide in 2020. Pancreatic cystic lesions (PCLs) are fluid-filled structures found within or on the surface of the pancreas, which can either be pre-malignant or have no malignant potential. While some PCLs are found in symptomatic patients, nowadays many PCLs are found incidentally in patients undergoing cross-sectional imaging for other reasons-so called 'incidentalomas'. Current methods of characterising PCLs are imperfect and vary hugely between institutions and countries. As such, there is a profound need for improved diagnostic algorithms. This could facilitate more accurate risk stratification of those PCLs that have malignant potential and reduce unnecessary surveillance. As PC continues to have such a poor prognosis, earlier recognition and risk stratification of PCLs may lead to better treatment protocols. This review will focus on the importance of biomarkers in the context of PCLs and PCand outline how current 'omics'-related work could contribute to the identification of a novel integrated biomarker profile for the risk stratification of patients with PCLs and PC.

Identifying Novel Biomarkers Ready for Evaluation in Low-Prevalence Populations for the Early Detection of Upper Gastrointestinal Cancers: A Systematic Review

Introduction

Detecting upper gastrointestinal (GI) cancers in primary care is challenging, as cancer symptoms are common, often non-specific, and most patients presenting with these symptoms will not have cancer. Substantial investment has been made to develop biomarkers for cancer detection, but few have reached routine clinical practice. We aimed to identify novel biomarkers for upper GI cancers which have been sufficiently validated to be ready for evaluation in low-prevalence populations.

Methods

We systematically searched MEDLINE, Embase, Emcare, and Web of Science for studies published in English from January 2000 to October 2019 (PROSPERO registration CRD42020165005). Reference lists of included studies were assessed. Studies had to report on second measures of diagnostic performance (beyond discovery phase) for biomarkers (single or in panels) used to detect pancreatic, oesophageal, gastric, and biliary tract cancers. We included all designs and excluded studies with less than 50 cases/controls. Data were extracted on types of biomarkers, populations and outcomes. Heterogeneity prevented pooling of outcomes.

Results

We identified 149 eligible studies, involving 22,264 cancer cases and 49,474 controls. A total of 431 biomarkers were identified (183 microRNAs and other RNAs, 79 autoantibodies and other immunological markers, 119 other proteins, 36 metabolic markers, 6 circulating tumour DNA and 8 other). Over half (n = 231) were reported in pancreatic cancer studies. Only 35 biomarkers had been investigated in at least two studies, with reported outcomes for that individual marker for the same tumour type. Apolipoproteins (apoAII-AT and apoAII-ATQ), and pepsinogens (PGI and PGII) were the most promising biomarkers for pancreatic and gastric cancer, respectively.

Conclusion

Most novel biomarkers for the early detection of upper GI cancers are still at an early stage of matureness. Further evidence is needed on biomarker performance in low-prevalence populations, in addition to implementation and health economic studies, before extensive adoption into clinical practice can be recommended.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-020-01571-z) contains supplementary material, which is available to authorized users.

LDL, HDL and endocrine-related cancer: From pathogenic mechanisms to therapies

Cholesterol is essential for a variety of functions in endocrine-related cells, including hormone and steroid production. We have reviewed the progress to date in research on the role of the main cholesterol-containing lipoproteins; low-density lipoprotein (LDL) and high-density lipoprotein (HDL), and their impact on intracellular cholesterol homeostasis and carcinogenic pathways in endocrine-related cancers. Neither LDL-cholesterol (LDL-C) nor HDL-cholesterol (HDL-C) was consistently associated with endocrine-related cancer risk. However, preclinical studies showed that LDL receptor plays a critical role in endocrine-related tumor cells, mainly by enhancing circulating LDL-C uptake and modulating tumorigenic signaling pathways. Although scavenger receptor type BI-mediated uptake of HDL could enhance cell proliferation in breast, prostate, and ovarian cancer, these effects may be counteracted by the antioxidant and anti-inflammatory properties of HDL. Moreover, 27-hydroxycholesterol a metabolite of cholesterol promotes tumorigenic processes in breast and epithelial thyroid cancer. Furthermore, statins have been reported to reduce the incidence of breast, prostate, pancreatic, and ovarian cancer in large clinical trials, in part because of their ability to lower cholesterol synthesis. Overall, cholesterol homeostasis deregulation in endocrine-related cancers offers new therapeutic opportunities, but more mechanistic studies are needed to translate the preclinical findings into clinical therapies.

Serum proteomics analysis of feline mammary carcinoma based on label-free and PRM techniques

Background

Feline mammary carcinoma is the third most common cancer that affects female cats.

Objectives

The purpose of this study was to screen differential serum proteins in feline and clarify the relationship between them and the occurrence of feline mammary carcinoma.

Methods

Chinese pastoral cats were used as experimental animals. Six serum samples from cats with mammary carcinoma (group T) and six serum samples from healthy cats (group C) were selected. Differential protein analysis was performed using a Label-free technique, while parallel reaction monitoring (PRM) was performed to verify the screened differential proteins.

Results

A total of 82 differential proteins were detected between group T and group C, of which 55 proteins were down regulated and 27 proteins were up regulated. Apolipoprotein A-I, Apolipoprotein A-II (ApoA-II), Apolipoprotein B (ApoB), Apolipoprotein C-III (ApoC-III), coagulation factor V, coagulation factor X, C1q, albumen (ALB) were all associated with the occurrence of feline mammary carcinoma. Differential proteins were involved in a total of 40 signaling pathways, among which the metabolic pathways associated with feline mammary carcinoma were the complement and coagulation cascade and cholesterol metabolism. According to the Label-free results, ApoB, ApoC-III, ApoA-II, FN1, an uncharacterized protein, and ALB were selected for PRM target verification. The results were consistent with the trend of the label-free.

Conclusions

This experimen is the first to confirm ApoA-II and ApoB maybe new feline mammary carcinoma biomarkers and to analyze their mechanisms in the development of such carcinoma in feline.

Pancreatic adenocarcinoma preferentially takes up and is suppressed by synthetic nanoparticles carrying apolipoprotein A-II and a lipid gemcitabine prodrug in mice

We hypothesised that synthetic HDL nanoparticles carrying a gemcitabine prodrug and apolipoprotein A-II (sHDLGemA2) would target scavenger receptor-B1 (SR-B1) to preferentially and safely deliver gemcitabine into pancreatic ductal adenocarcinoma (PDAC). We designed, manufactured and characterised sHDLGemA2 nanoparticles sized ~130 nm, incorporating 20 mol% of a gemcitabine prodrug within the lipid bilayer, which strengthens on adding ApoA-II. We measured their ability to inhibit growth in cell lines and cell-derived and patient-derived murine PDAC xenografts. Fluorescent-labelled sHDLGemA2 delivered gemcitabine inside xenografts. Xenograft levels of active gemcitabine after sHDLGemA2 were similar to levels after high-dose free gemcitabine. Growth inhibition in mice receiving 4.5 mg gemcitabine/kg/d, carried in sHDLGemA2, was equivalent to inhibition after high-dose (75 mg/kg/d) free gemcitabine, and greater than inhibition after low-dose (4.5 mg/kg/d) free gemcitabine. sHDLGemA2 slowed growth in semi-resistant cells and a resistant human xenograft. sHDLGemA2 targeted xenografts more effectively than sHDLGemA1. SR-B1 was over-expressed in PDAC cells and xenografts. Targeting by ApoA-II was suppressed by anti-SR-B1. Because sHDLGemA2 provided only ~6% of the free gemcitabine dose for an equivalent response, patient side effects can be greatly reduced, and the sHDLGemA2 concept should be developed through clinical trials.

Prospective Study Using Plasma Apolipoprotein A2-Isoforms to Screen for High-Risk Status of Pancreatic Cancer

Simple Summary

Apolipoprotein A2 isoforms (apoA2-i) have been identified as minimally invasive biomarkers for detecting pancreatic cancer (PC) and high-risk individuals for PC. We investigated the efficiency of an enrichment strategy for high-risk individuals using a combination of blood testing for apoA2-i with imaging examinations in the general population. We enrolled 5120 subjects in experimental pancreatic cancer screening, with 84 subjects (1.3%) showing abnormal results for apoA2-i. Pancreatic diseases were recognized in about 30% of subjects with an apoA2-ATQ/AT level of ≤35 μg/mL. Among them, 1 pancreatic cancer and 15 high-risk individuals with intraductal papillary mucinous neoplasm were detected. ApoA2-i has the potential to enrich PC and high-risk status by increasing the diagnostic probability before imaging examinations.

Abstract

Apolipoprotein A2-ATQ/AT (apoA2-ATQ/AT) has been identified as a minimally invasive biomarker for detecting pancreatic cancer (PC) and high-risk (HR) individuals for PC. To establish an efficient enrichment strategy for HR, we carried out a plasma apoA2-ATQ/AT level-based prospective screening study among the general population. The subjects for the screening study were recruited at six medical check-up facilities in Japan between October 2015 and January 2017. We evaluated the positive predictive value (PPV) of the plasma apoA2-ATQ/AT level of ≤35 μg/mL for detecting PC and HR. Furthermore, we prospectively confirmed its diagnostic accuracy with another post-diagnosis population in a cross-sectional study. We enrolled 5120 subjects in experimental screening, with 84 subjects (1.3%) showing positive results for apoA2-ATQ/AT. Pancreatic abnormalities were recognized in 26 of the 84 subjects from imaging examinations. Pancreatic abnormalities detected included 1 PC and 15 HR abnormalities, such as cystic lesions including intraductal papillary mucinous neoplasm. The PPV of apoA2-ATQ/AT for detecting PC and HR was 33.3%. Moreover, a combination study with another cross-sectional study revealed that the area under the curve for apoA2-ATQ/AT to distinguish PC from healthy controls was 0.903. ApoA2-ATQ/AT has the potential to enrich PC and HR by increasing the diagnostic probability before imaging examinations.

Apolipoprotein A2 Isoforms in Relation to the Risk of Myocardial Infarction: A Nested Case-Control Analysis in the JPHC Study

AIM

The fact that low concentrations of high-density lipoprotein cholesterol are associated with the risk of cardiovascular disease is well known, but high-density lipoprotein metabolism has not been fully understood. Apolipoprotein A2 (ApoA2) is the second-most dominant apolipoprotein of high-density lipoprotein. We tested the hypothesis that ApoA2 isoforms are inversely associated with myocardial infarction.

METHODS

We measured the plasma levels of three ApoA2 isoforms (ApoA2-ATQ/ATQ, ApoA2-ATQ/AT, ApoA2-AT/AT) in nested case-control study samples of 1:2 from the Japan Public Health-Center-based Study (JPHC Study): 106 myocardial infarction incidence cases and 212 controls.

RESULTS

ApoA2-AT/AT was inversely associated with risk of myocardial infarction, in a matched model (OR, 2.78; 95% CI, 1.26-6.09 for lowest compared with the highest quartile), but its association was attenuated after adjustment for smoking only (OR=2.13; 95% CI, 0.91-4.97) or drinking only (OR=2.11; 0.91-4.89), and the multivariable OR was 1.20 (95% CI, 0.41-3.57). Neither ApoA2-ATQ/ATQ nor ApoA2-ATQ/AT was associated with the risk of myocardial infarction.

CONCLUSIONS

Our nested case-control study did not show a significant association of ApoA2 isoforms with a risk of myocardial infarction.

Use of Biomarkers and Imaging for Early Detection of Pancreatic Cancer

Pancreatic cancer remains one of the deadliest cancers worldwide, and it is typically diagnosed late, with a poor prognosis. Early detection is the most important underlying factor for improving the prognosis of pancreatic cancer patients. One of the most effective strategies for detecting cancers at an early stage is screening of the general population. However, because of the low incidence of pancreatic cancer in the general population, the stratification of subjects who need to undergo further examinations by invasive and expensive modalities is important. Therefore, minimally invasive modalities involving biomarkers and imaging techniques that would facilitate the early detection of pancreatic cancer are highly needed. Multiple types of new blood biomarkers have recently been developed, including unique post-translational modifications of circulating proteins, circulating exosomes, microRNAs, and circulating tumor DNA. We previously reported that circulating apolipoprotein A2 undergoes unique processing in the bloodstream of patients with pancreatic cancer and its precancerous lesions. Additionally, we recently demonstrated a new method for measuring pancreatic proton density in the fat fraction using a fat–water magnetic resonance imaging technique that reflects pancreatic steatosis. In this review, we describe recent developments in potential biomarkers and imaging modalities for the early detection and risk stratification of pancreatic cancer, and we discuss current strategies for implementing screening programs for pancreatic cancer.

Multiplexed single-molecule enzyme activity analysis for counting disease-related proteins in biological samples

We established an ultrasensitive method for identifying multiple enzymes in biological samples by using a multiplexed microdevice-based single-molecule enzymatic assay. We used a paradigm in which we "count" the number of enzyme molecules by profiling their single enzyme activity characteristics toward multiple substrates. In this proof-of-concept study of the single enzyme activity-based protein profiling (SEAP), we were able to detect the activities of various phosphoric ester-hydrolyzing enzymes such as alkaline phosphatases, tyrosine phosphatases, and ectonucleotide pyrophosphatases in blood samples at the single-molecule level and in a subtype-discriminating manner, demonstrating its potential usefulness for the diagnosis of diseases based on ultrasensitive detection of enzymes.

Serum Derived Exosomes From Pancreatic Cancer Patients Promoted Metastasis: An iTRAQ-Based Proteomic Analysis

Background

Pancreatic cancer (PC) is one of the most aggressive malignancies and has a poor prognosis despite being extensively researched. The role of serum-derived exosomes in tumorigenesis and the development of PC is still unclear.

Method

The present study employed iTRAQ-based proteomic analysis to search for differences between the serum exosomes of PC patients and those from control patients. Then, bioinformatics methods were used to analyze the functions of the identified proteins, and the possible functions were verified through cell culture experiments.

Results

A total of 611 proteins were identified from exosomes, and 141 proteins were differentially expressed, with 91 up- and 50 down regulated proteins in PC cancer compared to healthy controls. Further analysis indicated that APOE serves as an important hub in the network. In addition, CRP, VWF, APOA2, NIN, and GSK3B potentially interact with many other proteins. We then tested the effect of patient serum-derived exosomes on pancreatic cancer cells and found that patient serum-derived exosomes, but not those from healthy controls, induced cell proliferation, migration, and EMT, supporting the role of exosomes in metastasis.

Conclusion

Our data suggest that exosomes derived from PC patients may promote PC metastasis.

Verification of the effectiveness of fucosylated haptoglobin as a pancreatic cancer marker in clinical diagnosis

BACKGROUND

Fucosylated haptoglobin detected by Pholiota squarrosa lectin (PhoSL) that had specificity for fucose α1-6 was reported as an effective biomarker for several gastrointestinal diseases. The aim of this study was to verify Fucosylated haptoglobin detected by Pholiota squarrosa lectin (PhoSL-HP) as a pancreatic cancer (PC) marker using a new method of PhoSL-ELISA.

METHODS

PhoSL-HP in sera from 98 PC patients and 158 non-PC samples including 32 intraductal papillary mucinous neoplasm (IPMN) patients, 21 chronic pancreatitis (CP) patients and 105 non-pancreatic disease controls (NPDC) were measured. We compared sensitivities, specificities and areas under the curves (AUC) of PhoSL-HP, CA19-9 and CEA as single markers. We also evaluated PhoSL-HP as combination marker by comparing AUC of CA19-9 combined with PhoSL-HP or CEA.

RESULTS

The sensitivities of PhoSL-HP, CA19-9 and CEA for PC were 58%, 76% and 42%, respectively. Although the specificity of PhoSL-HP for NPDC was inferior to both of CA19-9 and CEA, that for pancreatic diseases was higher than both of CA19-9 and CEA. Combined CA19-9 with PhoSL-HP, the AUC was significantly higher at 0.880 than single use of CA19-9 at 0.825 in case of distinguishing PC from other pancreatic diseases. In contrast, the AUC of CA19-9 was not elevated significantly when combined with CEA.

CONCLUSION

PhoSL-HP would be a useful marker for PC and have sufficient complementarity for CA19-9.

CA19-9 and apolipoprotein-A2 isoforms as detection markers for pancreatic cancer: a prospective evaluation

Recently, we identified unique processing patterns of apolipoprotein A2 (ApoA2) in patients with pancreatic cancer. Our study provides a first prospective evaluation of an ApoA2 isoform ("ApoA2-ATQ/AT"), alone and in combination with carbohydrate antigen 19-9 (CA19-9), as an early detection biomarker for pancreatic cancer. We performed ELISA measurements of CA19-9 and ApoA2-ATQ/AT in 156 patients with pancreatic cancer and 217 matched controls within the European EPIC cohort, using plasma samples collected up to 60 months prior to diagnosis. The detection discrimination statistics were calculated for risk scores by strata of lag-time. For CA19-9, in univariate marker analyses, C-statistics to distinguish future pancreatic cancer patients from cancer-free individuals were 0.80 for plasma taken ≤6 months before diagnosis, and 0.71 for >6-18 months; for ApoA2-ATQ/AT, C-statistics were 0.62, and 0.65, respectively. Joint models based on ApoA2-ATQ/AT plus CA19-9 significantly improved discrimination within >6-18 months (C = 0.74 vs. 0.71 for CA19-9 alone, p = 0.022) and ≤ 18 months (C = 0.75 vs. 0.74, p = 0.022). At 98% specificity, and for lag times of ≤6, >6-18 or ≤ 18 months, sensitivities were 57%, 36% and 43% for CA19-9 combined with ApoA2-ATQ/AT, respectively, vs. 50%, 29% and 36% for CA19-9 alone. Compared to CA19-9 alone, the combination of CA19-9 and ApoA2-ATQ/AT may improve detection of pancreatic cancer up to 18 months prior to diagnosis under usual care, and may provide a useful first measure for pancreatic cancer detection prior to imaging.

Clinical Significance of Plasma Apolipoprotein-AII Isoforms as a Marker of Pancreatic Exocrine Disorder for Patients with Pancreatic Adenocarcinoma Undergoing Chemoradiotherapy, Paying Attention to Pancreatic Morphological Changes

BACKGROUND

Circulating apolipoprotein-AII (apoAII-) ATQ/AT is a potential useful biomarker for early stage pancreatic ductal adenocarcinoma (PDAC), but its clinical significance in PDAC patients remains uncertain. The aim of the current study was to assess the usefulness of apoAII-ATQ/AT as a surrogate for the effect of chemoradiotherapy (CRT) and its association with pancreatic exocrine disorder, paying attention to morphological changes of the pancreas.

METHODS

In the 264 PDAC patients who were enrolled in our CRT protocol, the following parameters were measured at specified time points before and after CRT: serum levels of albumin, total cholesterol, and amylase as indices of pancreatic exocrine function, serum levels of CA19-9, and the pancreatic morphology including tumor size (TS), main pancreatic duct diameter (MPDD), and pancreatic parenchymal volume excluding tumor volume (PPV) by using computed tomography (CT) images. Plasma apoAII-ATQ/AT levels were simultaneously measured with enzyme-linked immunosorbent assay in 4 healthy volunteers and the 44 PDAC patients before and after CRT. Plasma apoAII-ATQ/AT levels after CRT were analyzed according to small/large-MPDD and small/large-PPV groups based on their median values after CRT. Plasma samples after CRT were measured after incubation with human pancreatic juice (PJ) to examine the relevance between apoAII isoforms and circulating pancreatic enzymes.

RESULTS

The serum levels of albumin, amylase, CA19-9, TS, MPDD, and PPV after CRT were significantly lower than those before CRT (median, before vs. after: 3.9 g/dl, 74 U/l, 180.2 U/ml, 58.1 mm, 4.0 mm, and 34.8 ml vs. 3.8, 59, 43.5, 55.6, 3.6, and 25.2). ApoAII-ATQ/AT levels (median, μg/ml) of PDAC patients before CRT were significantly lower than those in healthy volunteers: 32.9 vs. 61.2, and unexpectedly those after CRT significantly decreased: 14.7. The reduction rate of apoAII-ATQ/AT was not correlated with those of CA19-9 and TS, indicating that apoAII-ATQ/AT is not a tumor-specific marker. On the other hand, the patient group with large MPDD and small PV exhibited higher apoAII-ATQ levels than those with small MPDD and large PPV. The incubation of plasma samples after CRT with PJ did not alter apoAII-ATQ/AT and apoAII-AT levels but significantly decreased apoAII-ATQ levels, suggesting that circulating pancreatic enzymes markedly influenced apoAII-ATQ levels.

CONCLUSIONS

ApoAII-ATQ/AT levels are not useful for evaluation of clinical effect of CRT for PDAC, but apoAII isoforms are very useful to assess pancreatic exocrine disorder because pancreatic atrophy and insufficient secretion of circulating pancreatic enzymes are considered likely to influence apoAII-ATQ levels.

Large-scale clinical validation of biomarkers for pancreatic cancer using a mass spectrometry-based proteomics approach

We performed an integrated analysis of proteomic and transcriptomic datasets to develop potential diagnostic markers for early pancreatic cancer. In the discovery phase, a multiple reaction monitoring assay of 90 proteins identified by either gene expression analysis or global serum proteome profiling was established and applied to 182 clinical specimens. Nine proteins (P < 0.05) were selected for the independent validation phase and quantified using stable isotope dilution-multiple reaction monitoring-mass spectrometry in 456 specimens. Of these proteins, four proteins (apolipoprotein A-IV, apolipoprotein CIII, insulin-like growth factor binding protein 2 and tissue inhibitor of metalloproteinase 1) were significantly altered in pancreatic cancer in both the discovery and validation phase (P < 0.01). Moreover, a panel including carbohydrate antigen 19-9, apolipoprotein A-IV and tissue inhibitor of metalloproteinase 1 showed better performance for distinguishing early pancreatic cancer from pancreatitis (Area under the curve = 0.934, 86% sensitivity at fixed 90% specificity) than carbohydrate antigen 19-9 alone (71% sensitivity).

Overall, we present the panel of robust biomarkers for early pancreatic cancer diagnosis through bioinformatics analysis that combined transcriptomic and proteomic data as well as rigorous validation on a large number of independent clinical samples.

Proteomic biomarkers in body fluids associated with pancreatic cancer

Pancreatic cancer (PC) is a highly malignant disease that represents the fourth leading cancer-related death worldwide. There has been very little improvement in survival rates over recent years, and surgical resection remains the only reliable curative approach. Factors that contribute to this dismal prognosis for PC include its rapid progression and invasion, the absence of specific symptoms, and the little impact of available chemotherapy. Importantly, the management of this malignancy is also limited by the lack of highly specific and sensitive biomarkers for its diagnosis and follow-up, and their identification is therefore considered a promising strategy to improve outcomes in these patients. Numerous translational studies have explored the usefulness of body fluids as a non-invasive source of PC-specific biomarkers, and innovations in proteomic methods and technologies have provided a myriad of protein biomarkers for different cancers. The adoption of a proteomic approach has improved understanding of the biology of PC and contributed to the potential identification of protein biomarkers for this disease. This review considers the most recent research efforts to develop novel proteomic biomarkers in body fluids for PC.

Serum apolipoprotein A2 isoforms in autoimmune pancreatitis

Recently, apolipoprotein A2 (apoA2) isoforms have been reported as candidate serum/plasma biomarkers of pancreatic cancer. However, the distribution of apoA2 isoforms in patients with autoimmune pancreatitis (AIP) has not been investigated yet. In this study, we evaluated the distribution of serum apoA2 isoforms; i.e., homodimer apoA2-ATQ/ATQ, heterodimer apoA2-ATQ/AT, and homodimer apoA2-AT/AT, in AIP patients and healthy volunteers (HV) using enzyme-linked immunosorbent assays, and the clinical characteristics and serum levels of each apoA2 isoform in 32 AIP patients and 38 HV were investigated. The calculated apoA2-ATQ/AT levels of the AIP patients were significantly lower than those of the HV, which agreed with results obtained for patients with pancreatic cancer. Interestingly, most of the AIP patients exhibited high levels of apoA2-ATQ along with low levels of apoA2-AT, indicating that the processing of the C-terminal regions of apoA2 dimer was inhibited in the AIP patients. This specific distribution of serum apoA2 isoforms might provide important information about the disease states of AIP patients and aid the differential diagnosis of AIP versus pancreatic cancer.

Recent advances in proteomic profiling of pancreatic ductal adenocarcinoma and the road ahead

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers worldwide. However, there remain many unmet clinical needs, from diagnosis to treatment strategies. The inherent complexity of the molecular characteristics of PDAC has made it difficult to meet these challenges, rendering proteomic profiling of PDAC a critical area of research. Area covered: In this review, we present recent advances in mass spectrometry (MS) and its current application in proteomic studies on PDAC. In addition, we discuss future directions for research that can efficiently incorporate current MS-based technologies that address key issues of PDAC proteomics. Expert commentary: Compared with other cancer studies, little progress has been made in PDAC proteomics, perhaps attributed to the difficulty in performing in-depth and large-scale clinical studies on PDAC. However, recent advances in mass spectrometry can advance PDAC proteomics past the fundamental research stage.

BRCA1 promoter methylation in peripheral blood cells and predisposition to breast cancer

Early onset breast cancer is a common malignancy and cause of death among young women in KSA. In addition, the data from women have demonstrated that most patients present late with an advanced stage. The early detection of this disease would not only save patients' lives but would also have the potential to reduce the budget and the time required for treating and nursing advanced breast cancer patients. This review highlights the risk of developing breast cancer in women with the methylated BRCA1 promoter in their white blood cells and proposes the potential use of this epigenetic modification as a powerful molecular marker for the early detection of breast cancer.

Potential usefulness of apolipoprotein A2 isoforms for screening and risk stratification of pancreatic cancer

Given the low incidence of pancreatic cancer in the general population, screening of pancreatic cancer in the general population using invasive modalities is not feasible. Combination of invasive screening with noninvasive biomarkers for pancreatic cancer and its precancerous lesions has the potential to reduce mortality due to pancreatic cancer. In this review, we focus on biomarkers found in the blood that can indicate early-stage pancreatic cancer, and we discuss current strategies for screening for pancreatic cancer. We recently identified a unique alteration in apolipoprotein A2 isoforms in pancreatic cancer and its precancerous lesions, and we describe its clinical usefulness as a potential biomarker for the early detection and risk stratification of pancreatic cancer.

Plasma protein profiling in a stage defined pancreatic cancer cohort - Implications for early diagnosis

Pancreatic ductal adenocarcinoma (PDAC) is a disease where detection preceding clinical symptoms significantly increases the life expectancy of patients. In this study, a recombinant antibody microarray platform was used to analyze 213 Chinese plasma samples from PDAC patients and normal control (NC) individuals. The cohort was stratified according to disease stage, i.e. resectable disease (stage I/II), locally advanced (stage III) and metastatic disease (stage IV). Support vector machine analysis showed that all PDAC stages could be discriminated from controls and that the accuracy increased with disease progression, from stage I to IV. Patients with stage I/II PDAC could be discriminated from NC with high accuracy based on a plasma protein signature, indicating a possibility for early diagnosis and increased detection rate of surgically resectable tumors.

Apolipoproteins as Differentiating and Predictive Markers for Assessing Clinical Outcomes in Patients with Small Cell Lung Cancer

PURPOSE

The present study aimed to investigate the value of apolipoproteins, including ApoA-1, ApoC-III, and ApoE, in patients with small cell lung cancer (SCLC) as potential biomarkers for diagnosis, prognosis, and cancer progression.

MATERIALS AND METHODS

Lung samples were collected from 89 patients with SCLC. Nineteen lung samples from non-small cell lung cancer (NSCLC) patients and 12 normal lung tissues were used as controls. Expression profiles of ApoA-1, ApoC-III, and ApoE in different samples were examined using immunohistochemical methods, and the expression levels were correlated with cancer types, treatment, and outcomes using chi-square and Mann-Whitney tests.

RESULTS

Expression of ApoA-1 and ApoC-III in SCLC was significantly different, compared with that in NSCLC and normal lung tissues, and was correlated with recurrence of SCLC. Patients undergoing neoadjuvant chemotherapy before surgery showed significantly reduced expression of ApoA-1 and increased expression of ApoC-III and ApoE. Nevertheless, the expression levels of ApoA-1, ApoC-III, and ApoE were not correlated with SCLC staging.

CONCLUSION

ApoA-1 and ApoC-III may be used as differentiating and predictive markers for SCLC. ApoA-1, ApoC-III, and ApoE may be used to monitor the efficacy of chemotherapy.

Apolipoprotein A-II Plus Lipid Emulsion Enhance Cell Growth via SR-B1 and Target Pancreatic Cancer In Vitro and In Vivo

Background

Apolipoprotein A-II (ApoA-II) is down regulated in the sera of pancreatic ductal adenocarcinoma (PDAC) patients, which may be due to increase utilization of high density lipoprotein (HDL) lipid by pancreatic cancer tissue. This study examined the influence of exogenous ApoA-II on lipid uptake and cell growth in pancreatic cancer (PC) both in vitro and in vivo.

Methods

Cryo transmission electron microscopy (TEM) examined ApoA-II’s influence on morphology of SMOFLipid emulsion. The influence of ApoA-II on proliferation of cancer cell lines was determined by incubating them with lipid+/-ApoA-II and anti-SR-B1 antibody. Lipid was labeled with the fluorophore, DiD, to trace lipid uptake by cancer cells in vitro by confocal microscopy and in vivo in PDAC patient derived xenograft tumours (PDXT) by fluorescence imaging. Scavenger receptor class B type-1(SR-B1) expression in PDAC cell lines and in PDAC PDXT was measured by western blotting and immunohistochemistry, respectively.

Results

ApoA-II spontaneously converted lipid emulsion into very small unilamellar rHDL like vesicles (rHDL/A-II) and enhanced lipid uptake in PANC-1, CFPAC-1 and primary tumour cells as shown by confocal microscopy. SR-B1 expression was 13.2, 10.6, 3.1 and 2.3 fold higher in PANC-1, MIAPaCa-2, CFPAC-1 and BxPC3 cell lines than the normal pancreatic cell line (HPDE6) and 3.7 fold greater in PDAC tissue than in normal pancreas. ApoA-II plus lipid significantly increased the uptake of labeled lipid and promoted cell growth in PANC-1, MIAPaCa-2, CFPAC-1 and BxPC3 cells which was inhibited by anti SR-B1 antibody. Further, ApoA-II increased the uptake of lipid in xenografts by 3.4 fold.

Conclusion

Our data suggest that ApoA-II enhance targeting potential of lipid in pancreatic cancer which may have imaging and drug delivery potentialities.

Plasma biomarker for detection of early stage pancreatic cancer and risk factors for pancreatic malignancy using antibodies for apolipoprotein-AII isoforms

We recently reported that circulating apolipoprotein AII (apoAII) isoforms apoAII-ATQ/AT (C-terminal truncations of the apoAII homo-dimer) decline significantly in pancreatic cancer and thus might serve as plasma biomarkers for the early detection of this disease. We report here the development of novel enzyme-linked immunosorbent assays (ELISAs) for measurement of apoAII-ATQ/AT and their clinical applicability for early detection of pancreatic cancer. Plasma and serum concentrations of apoAII-ATQ/AT were measured in three independent cohorts, which comprised healthy control subjects and patients with pancreatic cancer and gastroenterologic diseases (n = 1156). These cohorts included 151 cases of stage I/II pancreatic cancer. ApoAII-ATQ/AT not only distinguished the early stages of pancreatic cancer from healthy controls but also identified patients at high risk for pancreatic malignancy. AUC values of apoAII-ATQ/AT to detect early stage pancreatic cancer were higher than those of CA19–9 in all independent cohorts. ApoAII-ATQ/AT is a potential biomarker for screening patients for the early stage of pancreatic cancer and identifying patients at risk for pancreatic malignancy (161 words).

ACTN4 copy number increase as a predictive biomarker for chemoradiotherapy of locally advanced pancreatic cancer

Background:

Several clinical trials have compared chemotherapy alone and chemoradiotherapy (CRT) for locally advanced pancreatic cancer (LAPC) treatment. However, predictive biomarkers for optimal therapy of LAPC remain to be identified.

We retrospectively estimated amplification of the ACTN4 gene to determine its usefulness as a predictive biomarker for LAPC.

Methods:

The copy number of ACTN4 in 91 biopsy specimens of LAPC before treatment was evaluated using fluorescence in situ hybridisation (FISH).

Results:

There were no statistically significant differences in overall survival (OS) or progression-free survival (PFS) of LAPC between patients treated with chemotherapy alone or with CRT. In a subgroup analysis of patients treated with CRT, patients with a copy number increase (CNI) of ACTN4 had a worse prognosis of OS than those with a normal copy number (NCN) of ACTN4 (P=0.0005, log-rank test). However, OS in the subgroup treated with chemotherapy alone was not significantly different between patients with a CNI and a NCN of ACTN4. In the patients with a NCN of ACTN4, the median survival time of PFS in CRT-treated patients was longer than that of patients treated with chemotherapy alone (P=0.049).

Conclusions:

The copy number of ACTN4 is a predictive biomarker for CRT of LAPC.

The molecular significance of methylated BRCA1 promoter in white blood cells of cancer-free females

BACKGROUND

BRCA1 promoter methylation has been detected in DNA from peripheral blood cells of both breast cancer patients and cancer-free females. However, the pathological significance of this epigenetic change in white blood cells (WBC) remains an open question. In this study, we hypothesized that if constitutional BRCA1 methylation reflects an elevated risk for developing breast cancer (BC), WBC that harbor methylated BRCA1 in both cancer-free females and BC patients should exhibit similar molecular changes.

METHODS

BRCA1 promoter methylation was examined by methylation-specific PCR in WBC from 155 breast cancer patients and 143 cancer-free females. The Human Breast Cancer EpiTect Methyl II Signature PCR Array and The Human Breast Cancer RT2 Profiler™ PCR Array were used to study the methylation status and the expression profile of several breast cancer-related genes, respectively. In addition, we used label-free MS-based technique to study protein expression in plasma.

RESULTS

We have shown that 14.2% of BC patients and 9.1% of cancer-free females (carriers) harbored methylated BRCA1 promoter in their WBC. Interestingly, 66.7% of patients harbored methylated BRCA1 promoter in both WBC and tumors. Importantly, we have shown the presence of epigenetic changes in 9 other BC-related genes in WBC of both patients and carriers. Additionally, BRCA1 and 15 other important cancer -related genes were found to be differentially expressed in WBC from patients and carriers as compared to controls. Furthermore, we have shown that the carriers exhibited a unique plasma protein pattern different from those of BC patients and controls, with 10 proteins similarly differentially expressed in patients and carriers as compared to controls.

CONCLUSIONS

The present results suggest the presence of a strong link between aberrant methylation of the BRCA1 promoter in WBC and breast cancer -related molecular changes, which indicate the potential predisposition of the carriers for developing breast cancer. This informs the potential use of the aberrant methylation of BRCA1 promoter in WBC as a powerful non-invasive molecular marker for detecting predisposed individuals at a very early age.

Size and charge of nanoparticles following incubation with human plasma of healthy and pancreatic cancer patients

When nanoparticles (NPs) enter a biological environment, proteins bind to their surface forming a protein coating, which alters NP features giving it a biological identity, which controls its physiological response. The NP biological identity (size, charge and aggregation state) does strictly correlate with its physicochemical properties and the nature of the biological environment. While the former relationship has been extensively investigated, whether and how alterations in the physiological environment affect the biological identity of the NPs remains unclear. In this work we enrolled healthy and histologically proven pancreatic cancer patients. A statistically significant reduction in the level of clinically relevant proteins in cancer patients occurred. Positively and negatively charged lipid nanoparticles with two different surface chemistries (plain and PEGylated) were incubated with human plasma from both groups and characterized thoroughly by dynamic light scattering and zeta potential measurements. Only when plain positively charged NPs were tested, significant difference in zeta-potential between healthy and pancreatic cancer groups was found. This result implies that pooling human plasma from healthy volunteers might lead to a bias and thus unpredictable consequences in regard to previously optimized targeting profile.

Serum protein signatures differentiating autoimmune pancreatitis versus pancreatic cancer

Autoimmune pancreatitis (AIP) is defined by characteristic lymphoplasmacytic infiltrate, ductal strictures and a pancreatic enlargement or mass that can mimic pancreatic cancer (PaCa). The distinction between this benign disease and pancreatic cancer can be challenging. However, an accurate diagnosis may pre-empt the misdiagnosis of cancer, allowing the appropriate medical treatment of AIP and, consequently, decreasing the number of unnecessary pancreatic resections.

Mass spectrometry (MS) and two-dimensional differential gel electrophoresis (2D-DIGE) have been applied to analyse serum protein alterations associated with AIP and PaCa, and to identify protein signatures indicative of the diseases. Patients' sera were immunodepleted from the 20 most prominent serum proteins prior to further 2D-DIGE and image analysis. The identity of the most-discriminatory proteins detected, was performed by MS and ELISAs were applied to confirm their expression. Serum profiling data analysis with 2D-DIGE revealed 39 protein peaks able to discriminate between AIP and PaCa. Proteins were purified and further analysed by MALDI-TOF-MS. Peptide mass fingerprinting led to identification of eleven proteins. Among them apolipoprotein A-I, apolipoprotein A-II, transthyretin, and tetranectin were identified and found as 3.0-, 3.5-, 2-, and 1.6-fold decreased in PaCa sera, respectively, whereas haptoglobin and apolipoprotein E were found to be 3.8- and 1.6-fold elevated in PaCa sera. With the exception of haptoglobin the ELISA results of the identified proteins confirmed the 2D-DIGE image analysis characteristics. Integration of the identified serum proteins as AIP markers may have considerable potential to provide additional information for the diagnosis of AIP to choose the appropriate treatment.

Proteomic approaches to the discovery of cancer biomarkers for early detection and personalized medicine

Cancer biomarkers for the early detection of malignancies and selection of therapeutic strategies have been requested in the clinical field. Accurate and informative cancer biomarkers hold significant promise for improvements in the early detection of disease and in the selection of the most effective therapeutic strategies. Recently, significant progress in the comprehensive analysis of the human genome, epigenome, transcriptome, proteome and metabolome has led to revolutionary changes in the discovery of cancer biomarkers. The Human Proteome Organization has launched a global Human Proteome Project to map the entire human protein set. The Human Proteome Project research group has focused on three working proteomic pillars-mass spectrometry-based, antibody-based and knowledge-based proteomics-and each of these technologies is advancing rapidly. In this review, we introduce the proteomic platforms that are currently being used for cancer biomarker discovery, and describe examples of novel cancer biomarkers that were identified with each proteomic technology.