Tumor-associated autoantibodies as diagnostic and prognostic biomarkers

Anti-FDX1 Autoantibody as a Potential Biomarker for Non-Small Cell Lung Cancer Detection

BACKGROUND

Autoantibodies can be readily identified prior to biopsy and may serve as valuable biomarkers for cancer detection. Ferredoxin 1 (FDX1) is a key regulator in the process of cuproptosis and affects the prognosis of lung cancer. In this study, we investigated whether the anti-FDX1 autoantibody could serve as a novel biomarker for the detection of non-small cell lung cancer (NSCLC).

METHODS

A total of 1,155 plasma samples were divided into the verification and validation groups. The expression levels of the anti-FDX1 autoantibody in 414 patients with NSCLC, 327 patients with benign pulmonary nodules (BPN), and 414 normal controls (NC) were detected using ELISA. Western blotting and immunofluorescence analyses were performed to confirm the ELISA results.

RESULTS

Plasma anti-FDX1 autoantibody levels were significantly higher in patients with NSCLC than in patients with BPN and NCs in the verification and validation groups. The ELISA results were confirmed by Western blotting and immunofluorescence. The anti-FDX1 autoantibody distinguished NSCLC from NC and BPN with an AUC (95% confidence interval) of 0.806 (0.772-0.839) and 0.627 (0.584-0.670), respectively.

CONCLUSIONS

Our study demonstrated the potential benefits of the anti-FDX1 autoantibody as a novel biomarker for NSCLC detection.

IMPACT

These findings suggested that the anti-FDX1 autoantibody may facilitate the detection of NSCLC.

Novel combined tumor autoantibody detection in serological diagnosis of gastric cancer

OBJECTIVE

Gastric cancer (GC) is a highly prevalent malignancy, yet its early diagnosis rate is generally low. Therefore, we have established a serum-based combined detection method based on tumor autoantibodies aimed at improving the diagnostic rate of gastric cancer.

METHODS

Through clinical studies, we selected a series of proteins aberrantly expressed in gastric cancer patients, including RalA, Survivin, NY-ESO-1, p53, Cyclin B1, and Koc, and expressed and purified them using prokaryotic expression and nickel column chromatography.

RESULTS

The levels of autoantibodies in the serum of gastric cancer patients and healthy individuals were measured using enzyme-linked immunosorbent assay (ELISA), and the diagnostic value of the combined detection of tumor autoantibodies for gastric cancer was evaluated through receiver operating characteristic (ROC) curve analysis. The levels of autoantibodies against RalA, Survivin, NY-ESO-1, p53, and Cyclin B1 in the serum of gastric cancer patients were significantly higher than those in healthy individuals (P < 0.05), while the level of Koc showed no significant difference between the two groups (P > 0.05), suggesting that Koc may not be suitable for serological diagnosis of gastric cancer. ROC analysis of the combined levels of autoantibodies against RalA, Survivin, NY-ESO-1, p53, and Cyclin B1 for gastric cancer diagnosis achieved a sensitivity of 73.68% and specificity of 78.13%, with an AUC value of 0.8767.

CONCLUSION

The combined tumor autoantibody detection established in this study may have promising potential applications in early screening and diagnosis of gastric cancer.

Biological biomarkers of oral cancer

The oral squamous cell carcinoma (OSCC) 5 year survival rate of 41% has marginally improved in the last few years, with less than a 1% improvement per year from 2005 to 2017, with higher survival rates when detected at early stages. Based on histopathological grading of oral dysplasia, it is estimated that severe dysplasia has a malignant transformation rate of 7%-50%. Despite these numbers, oral dysplasia grading does not reliably predict its clinical behavior. Thus, more accurate markers predicting oral dysplasia progression to cancer would enable better targeting of these lesions for closer follow-up, especially in the early stages of the disease. In this context, molecular biomarkers derived from genetics, proteins, and metabolites play key roles in clinical oncology. These molecular signatures can help predict the likelihood of OSCC development and/or progression and have the potential to detect the disease at an early stage and, support treatment decision-making and predict treatment responsiveness. Also, identifying reliable biomarkers for OSCC detection that can be obtained non-invasively would enhance management of OSCC. This review will discuss biomarkers for OSCC that have emerged from different biological areas, including genomics, transcriptomics, proteomics, metabolomics, immunomics, and microbiomics.

Enhanced Lung Cancer Detection Using a Combined Ratio of Antigen-Autoantibody Immune Complexes against CYFRA 21-1 and p53

The early detection of lung cancer (LC) improves patient outcomes, but current methods have limitations. Autoantibodies against tumor-associated antigens have potential as early biomarkers. This study evaluated the 9G testTM Cancer/Lung, measuring circulating complexes of two antigen-autoantibody immune complexes (AIC) against their respective free antigens (CYFRA 21-1 and p53) for LC diagnosis. We analyzed 100 LC patients and 119 healthy controls using the 9G testTM Cancer/Lung, quantifying the levels of AICs (CYFRA 21-1-Anti-CYFRA 21-1 autoantibody immune complex (CIC) and p53-Anti-p53 autoantibody immune complex (PIC)), free antigens (CYFRA 21-1 and p53), and ratios of AICs/antigens (LC index). The levels of the CICs and PICs were significantly elevated in LC compared to the controls (p < 0.0062 and p < 0.0026), while free antigens showed no significant difference. The CIC/CYFRA 21-1 and PIC/p53 ratios were also significantly higher in LC (all, p < 0.0001). The LC index, when combining both ratios, exhibited the best diagnostic performance with an area under the curve (AUC) of 0.945, exceeding individual CICs, PICs, and free antigens (AUCs ≤ 0.887). At a cut-off of 3.60, the LC index achieved 81% sensitivity and 95% specificity for LC diagnosis. It detected early-stage (Stage I-II) LC with 87.5% sensitivity, exceeding its performance in advanced stages (72.7%). The LC index showed no significant differences based on age, gender, smoking status (former, current, or never smoker), or pack years smoked. The LC index demonstrates promising potential for early LC diagnosis, exceeding conventional free antigen markers.

Non-endoscopic Screening for Esophageal Squamous Cell Carcinoma: Recent Advances

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most common tumors in the gastrointestinal tract, and China has a high incidence area with a high burden on the disease. As early symptoms of ESCC are not obvious, the mortality rate is high, and it is often diagnosed in the intermediate and advanced stages. However, early screening and treatment may reduce morbidity and mortality.

METHODS

Screening methods are divided into endoscopic and non-endoscopic screening.

RESULTS

Endoscopic screening cannot be widely used because of its invasive nature and high cost. Currently, non-endoscopic screening consists primarily of tumor biomarkers and cytology, and tumor biomarkers including autoantibodies, circulating tumor cells, circulating tumor DNA, exosomes and serum metabolomics are more likely to be effective. But the efficiency of early diagnosis of esophageal cancer is low and the accuracy of screening needs to be improved. The aim of this study is to summarize advances in non-endoscopic esophageal cancer screening and strategies to provide a scientific basis and research idea for esophageal cancer prevention and control.

CONCLUSIONS

Non-endoscopic screening is better than endoscopic screening. And the application of tumor biomarkers is much better than other non-endoscopic screening methods.

Tumor-Infiltrating B Lymphocytes: Promising Immunotherapeutic Targets for Primary Liver Cancer Treatment

Hepatocellular carcinoma and cholangiocarcinoma are the fourth most lethal primary cancers worldwide. Therefore, there is an urgent need for therapeutic strategies, including immune cell targeting therapies. The heterogeneity of liver cancer is partially explained by the characteristics of the tumor microenvironment (TME), where adaptive and innate immune system cells are the main components. Pioneering studies of primary liver cancers revealed that tumor-infiltrating immune cells and their dynamic interaction with cancer cells significantly impacted carcinogenesis, playing an important role in cancer immune evasion and responses to immunotherapy treatment. In particular, B cells may play a prominent role and have a controversial function in the TME. In this work, we highlight the effect of B lymphocytes as tumor infiltrates in relation to primary liver cancers and their potential prognostic value. We also present the key pathways underlying B-cell interactions within the TME, as well as the way that a comprehensive characterization of B-cell biology can be exploited to develop novel immune-based therapeutic approaches.

p53 and p63 Proteoforms Derived from Alternative Splicing Possess Differential Seroreactivity in Colorectal Cancer with Distinct Diagnostic Ability from the Canonical Proteins

Colorectal cancer (CRC) is the third most common cancer and the second most frequent cause of cancer-related death worldwide. The detection in plasma samples of autoantibodies against specific tumor-associated antigens has been demonstrated to be useful for the early diagnosis of CRC by liquid biopsy. However, new studies related to the humoral immune response in cancer are needed to enable blood-based diagnosis of the disease. Here, our aim was to characterize the humoral immune response associated with the different p53 and p63 proteoforms derived from alternative splicing and previously described as aberrantly expressed in CRC. Thus, here we investigated the diagnostic ability of the twelve p53 proteoforms and the eight p63 proteoforms described to date, and their specific N-terminal and C-terminal end peptides, by means of luminescence HaloTag beads immunoassays. Full-length proteoforms or specific peptides were cloned as HaloTag fusion proteins and their seroreactivity analyzed using plasma from CRC patients at stages I-IV (n = 31), individuals with premalignant lesions (n = 31), and healthy individuals (n = 48). p53γ, Δ40p53β, Δ40p53γ, Δ133p53γ, Δ160p53γ, TAp63α, TAp63δ, ΔNp63α, and ΔNp63δ, together with the specific C-terminal end α and δ p63 peptides, were found to be more seroreactive against plasma from CRC patients and/or individuals with premalignant lesions than from healthy individuals. In addition, ROC (receiver operating characteristic) curves revealed a high diagnostic ability of those p53 and p63 proteoforms to detect CRC and premalignant individuals (AUC higher than 85%). Finally, electrochemical biosensing platforms were employed in POC-like devices to investigate their usefulness for CRC detection using selected p53 and p63 proteoforms. Our results demonstrate not only the potential of these biosensors for the simultaneous analysis of proteoforms' seroreactivity, but also their convenience and versatility for the clinical detection of CRC by liquid biopsy. In conclusion, we here show that p53 and p63 proteoforms possess differential seroreactivity in CRC patients in comparison to controls, distinctive from canonical proteins, which should improve the diagnostic panels for obtaining a blood-based biomarker signature for CRC detection.

Circulating tumor-associated autoantibodies as novel diagnostic biomarkers in pancreatic adenocarcinoma

To develop a superior diagnostic approach for pancreatic adenocarcinoma (PAAC), the present study prospectively included 338 PAAC patients, 294 normal healthy volunteers (NHV), 122 chronic pancreatitis (CP) patients and 100 patients with non-PAAC malignancies. In the identification phase, HuProt Human Proteome Microarray, comprising 21 065 proteins, was used to identify serum tumor-associated autoantibodies (TAAbs) candidates differentiating PAAC (n = 30) from NHV (n = 30). A PAAC-focused array containing 165 differentially expressed TAAbs identified was subsequently adopted in the validation phase (n = 712) for specificity and sensitivities. The multivariate TAAbs signature for differentiation PAAC from controls (NHV + CP) identified five candidates, namely the IgG-type TAAbs against CLDN17, KCNN3, SLAMF7, SLC22A11 and OR51F2. Multivariate logistic performance model of y = (22.893 × CA19-9 + 0.68 × CLDN17 - 4.012) showed a significant better diagnostic accuracy than that of CA19-9 and CLDN17 in differentiating PAAC from controls (NHV + CP) (AUC = 0.97, 0.92 and 0.82, respectively, P-value < .0001). We further tested the autoantigen level of CLDN17 by ELISA in 82 sera samples from PAAC (n = 42), CP (n = 24) and NHV (n = 16). Similarly, the model showed superior diagnostic performance than that of CA19-9 and CLDN17 (AUC = 0.93, 0.83 and 0.81, respectively, P-value < .0001) in differentiating PAAC from controls. In conclusion, our study is the first to characterize the circulating TAAbs signatures in PAAC. The results showed that CLDN17 combined with CA19-9 provided potentially clinical value and may serve as noninvasive novel biomarkers for PAAC diagnosis.

Anti-CXCL8 Autoantibody: A Potential Diagnostic Biomarker for Esophageal Squamous Cell Carcinoma

Background and Objectives: Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies. Anti-tumor associated antigen autoantibodies (TAAbs) can be used as biomarkers for tumor detection. The aim of this study was to identify a reliable TAAb as the diagnostic marker for ESCC. Materials and Methods: The Cancer Genome Atlas (TCGA) database was used to screen candidate genes. The mRNA expression of the key gene was then verified by micro array dataset GSE44021 from the Gene Expression Omnibus (GEO) database and the diag nostic value of the corresponding autoantibody to the key gene in ESCC was detected by enzyme-linked im muno sorbent assay (ELISA). Results: CXCL8 was identified as the key gene. The dataset GSE44021 showed that CXCL8 mRNA expression was prominently over-expressed in ESCC tissues compared with normal tissues. ELISA results showed that the level of anti-CXCL8 autoantibody in ESCC patients was significantly higher than in normal controls and the receiver operating char ac teristic (ROC) curve indicated that anti-CXCL8 autoantibody could discriminate ESCC patients from normal controls, with the area under the ROC curve (AUC) for the verification cohort, and the validation cohort were 0.713 and 0.751, respectively. Conclusions: Our study illustrated that anti-CXCL8 autoantibody had good diagnostic value, and may become a candidate biomarker for ESCC.

Facets of ICP-MS and their potential in the medical sciences-Part 2: nanomedicine, immunochemistry, mass cytometry, and bioassays

Inductively coupled-plasma mass spectrometry (ICP-MS) has transformed our knowledge on the role of trace and major elements in biology and has emerged as the most versatile technique in elemental mass spectrometry. The scope of ICP-MS has dramatically changed since its inception, and nowadays, it is a mature platform technology that is compatible with chromatographic and laser ablation (LA) systems. Over the last decades, it kept pace with various technological advances and was inspired by interdisciplinary approaches which endorsed new areas of applications. While the first part of this review was dedicated to fundamentals in ICP-MS, its hyphenated techniques and the application in biomonitoring, isotope ratio analysis, elemental speciation analysis, and elemental bioimaging, this second part will introduce relatively current directions in ICP-MS and their potential to provide novel perspectives in the medical sciences. In this context, current directions for the characterisation of novel nanomaterials which are considered for biomedical applications like drug delivery and imaging platforms will be discussed while considering different facets of ICP-MS including single event analysis and dedicated hyphenated techniques. Subsequently, immunochemistry techniques will be reviewed in their capability to expand the scope of ICP-MS enabling analysis of a large range of biomolecules alongside elements. These methods inspired mass cytometry and imaging mass cytometry and have the potential to transform diagnostics and treatment by offering new paradigms for personalised medicine. Finally, the interlacing of immunochemistry methods, single event analysis, and functional nanomaterials has opened new horizons to design novel bioassays which promise potential as assets for clinical applications and larger screening programs and will be discussed in their capabilities to detect low-level proteins and nucleic acids.

Performance of screening tests for esophageal squamous cell carcinoma: a systematic review and meta-analysis

BACKGROUND AND AIMS

This systematic review and meta-analysis aims to compare the pooled diagnostic accuracy of the currently available esophageal squamous cell carcinoma (ESCC) screening tests.

METHODS

A comprehensive literature search of Embase and Medline (up to October 31, 2020) was performed to identify eligible studies. We pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for ESCC screening tools using a bivariate random-effects model. The summary receiver operating characteristic curves with area under the curve (AUC) were plotted for each screening test.

RESULTS

We included 161 studies conducted in 81 research articles involving 32,209 subjects. The pooled sensitivity, specificity, and AUC of the major screening tools were respectively as follows: endoscopy (peroral endoscopy): .94 (95% confidence interval [CI], .87-.97), .92 (95% CI, .87-.95), and .97 (95% CI, .96-.99); endoscopy (transnasal endoscopy): .85 (95% CI, .70-.93), .96 (95% CI, .91-.98), and .97 (95% CI, .95-.98); microRNA: .77 (95% CI, .75-.80), .78 (95% CI, .75-.80), and .85 (95% CI, .81-.87); autoantibody: .45 (95% CI, .36-.53), .91 (95% CI, .89-.93), and .84 (95% CI, .81-.87); and cytology: .82 (95% CI, .60-.93), .97 (95% CI, .88-.99), and .97 (95% CI, .95-.98). There was high heterogeneity.

CONCLUSIONS

The diagnostic accuracy seemed to be comparable between cytology and endoscopy, whereas autoantibody and microRNAs bear potential as future noninvasive screening tools for ESCC. To reduce ESCC-related death in high-risk populations, it is important to develop a more accurate and less-invasive screening test.

Use of Autoreactive Antibodies in Blood of Patients with Pancreatic Intraductal Papillary Mucinous Neoplasms (IPMN) for Grade Distinction and Detection of Malignancy

(1) Background: A reliable non-invasive distinction between low- and high-risk pancreatic intraductal papillary mucinous neoplasms (IPMN) is needed to effectively detect IPMN with malignant potential. This would improve preventative care and reduce the risk of developing pancreatic cancer and overtreatment. The present study aimed at exploring the presence of autoreactive antibodies in the blood of patients with IPMN of various grades of dysplasia. (2) Methods: A single-center cohort was studied composed of 378 serum samples from patients with low-grade IPMN (n = 91), high-grade IPMN (n = 66), IPMN with associated invasive cancer (n = 30), pancreatic ductal adenocarcinoma (PDAC) stages T1 (n = 24) and T2 (n = 113), and healthy controls (n = 54). A 249 full-length recombinant human protein microarray was used for profiling the serum samples. (3) Results: 14 proteins were identified as potential biomarkers for grade distinction in IPMN, yielding high specificity but mediocre sensitivity. (4) Conclusions: The identified autoantibodies are potential biomarkers that may assist in the detection of malignancy in IPMN patients.

Application Value Analysis of Seven-Autoantibody Panel in the Lung Cancer Screening in Yunnan

Objective

To study the application value of seven-autoantibody (anti-CAGE, anti-GAGE7, anti-GBU4-5, anti-MAGE A1, anti-P53, and anti-PGP9.5, anti-SOX2) in lung cancer (LC) screening in Yunnan.

Methods

The clinical data of 329 lung cancer patients and 202 nonlung cancer controls in the First People's Hospital of Yunnan Province from November 2018 to April 2022 were retrospectively analyzed. The detection results of anti-CAGE, anti-GAGE7, anti-GBU4-5, anti-MAGE A1, anti-P53, anti-PGP9.5, and anti-SOX2 were collected. The receiver operating curve (ROC) was used to analyze the value of these seven-autoantibody in the detection of LC alone and in combination, and the area under the curve (AUC), sensitivity, specificity, and cut-off values were calculated.

Results

The levels of anti-CAGE, anti-GAGE7, anti-GBU4-5, anti-MAGE A1, anti-P53, anti-PGP9.5 and anti-SOX2 in LC patients were significantly higher than those in the controls, and the differences were statistically significant (P < 0.001). The AUC of anti-CAGE, anti-GAGE7, anti-GBU4-5, anti-MAGE A1, anti-P53, anti-PGP9.5, and anti-SOX2 for the diagnosis of LC were 0.586 (95% CI: 0.537-0.634, P < 0.001), 0.620 (95% CI: 0.572-0.667, P < 0.001), 0.570 (95% CI: 0.521-0.619, P=0.007), 0.612 (95% CI: 0.563-0.660, P < 0.007) 0.001), 0.561 (95% CI: 0.510-0.611, P=0.019), 0.667 (95% CI: 0.619-0.715, P < 0.001), 0.587 (95% CI: 0.538-0.636, P < 0.001), respectively. The AUC of combined detection of LC was 0.719 (95% CI: 0.676-0.761, P < 0.001). The positive rate of the combined detection of seven-autoantibody in the LC group was 48.02% (158/329), which was significantly higher than that of the control group (13.86% (28/202)), the difference was statistically significant (χ 2 = 64.183, P < 0.001).

Conclusion

The individual detection and combined detection of the seven-autoantibody have a certain value in the diagnosis of LC in Yunnan, and it can provide a certain reference for clinical LC screening.

B-Cell-Based Immunotherapy: A Promising New Alternative

The field of immunotherapy has undergone radical conceptual changes over the last decade. There are various examples of immunotherapy, including the use of monoclonal antibodies, cancer vaccines, tumor-infecting viruses, cytokines, adjuvants, and autologous T cells carrying chimeric antigen receptors (CARs) that can bind cancer-specific antigens known as adoptive immunotherapy. While a lot has been achieved in the field of T-cell immunotherapy, only a fraction of patients (20%) see lasting benefits from this mode of treatment, which is why there is a critical need to turn our attention to other immune cells. B cells have been shown to play both anti- and pro-tumorigenic roles in tumor tissue. In this review, we shed light on the dual nature of B cells in the tumor microenvironment. Furthermore, we discussed the different factors affecting the biology and function of B cells in tumors. In the third section, we described B-cell-based immunotherapies and their clinical applications and challenges. These current studies provide a springboard for carrying out future mechanistic studies to help us unleash the full potential of B cells in immunotherapy.

On the Road to Accurate Protein Biomarkers in Prostate Cancer Diagnosis and Prognosis: Current Status and Future Advances

Prostate cancer (PC) is a leading cause of morbidity and mortality among men worldwide. Molecular biomarkers work in conjunction with existing clinicopathologic tools to help physicians decide who to biopsy, re-biopsy, treat, or re-treat. The past decade has witnessed the commercialization of multiple PC protein biomarkers with improved performance, remarkable progress in proteomic technologies for global discovery and targeted validation of novel protein biomarkers from clinical specimens, and the emergence of novel, promising PC protein biomarkers. In this review, we summarize these advances and discuss the challenges and potential solutions for identifying and validating clinically useful protein biomarkers in PC diagnosis and prognosis. The identification of multi-protein biomarkers with high sensitivity and specificity, as well as their integration with clinicopathologic parameters, imaging, and other molecular biomarkers, bodes well for optimal personalized management of PC patients.

Autoimmunity Profiles as Prognostic Indicators in Patients with Colorectal Cancer versus Those with Cancer at Other Sites: A Prospective Study

Colorectal cancer represents a paradigmatic model of inflammatory carcinogenesis accompanied by the production of several kinds of tumor-associated autoantibodies (TAABs). The specific aim of this study is to define the clinical impact of the presence of non-specific circulating TAABs in a cohort of cancer patients and to establish whether significant differences were present between colorectal cancer and cancers at other sites. For this aim a prospective study was developed and a five-year survival analysis performed. Indirect immunofluorescence on rat tissues for non-organ specific autoantibodies (NOSAs: liver-kidney-stomach), on rat colon substrates (colon-related autoantibodies, CAAs) and on HEp-2 cell lines was performed. NOSA positivity was more frequent in patients with colorectal cancer than in those with cancer at other sites. Survival analysis demonstrated a significantly worse prognosis in cancer patients positive for TAABs. CAA positivity is a predictor of survival, independently from the presence of comorbidities, and HEp-2 reactivity was a strong predictor of survival in a stepwise Cox-regression model, including stage at diagnosis. Overall overproduction of TAABs is associated with advanced oncological disease, the presence of metastasis, and poorer prognosis of cancer patients.

Immunoassay detection of tumor-associated autoantibodies using protein G bioconjugated to nanomagnet-silica decorated with Au@Pd nanoparticles

A colorimetric immunosensor was developed for the detection of tumor-associated anti-p53 autoantibodies (anti-p53aAbs). The immunosensor platform was prepared by immobilizing human-protein (p53Ag) onto a high binding 96-well plate. The immunoassay was based on the immunometric sandwich protocol, and protein G functionalized nanomagnet-silica nanoparticles decorated with Au@Pd (Fe₃O₄@SiO₂-NH₂-Au@Pd_0.30NPs-protG) was used as the detection nanobioprobe. The Fe₃O₄@SiO₂-NH₂-Au@Pd_0.30NPs-protG exhibited a high binding affinity for the captured anti-p53aAbs and high catalytic performance towards the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB). The oxidation of TMB resulted in significant color change and a UV-vis absorption signal. The detection was achieved by measuring the changes in UV-Vis absorption as the concentrations of anti-p53aAbs changed. The apparent binding affinity (K_D) between the p53aAbs and Fe₃O₄@SiO₂-NH₂-Au@Pd_0.30NPs-protG was 35.2 ng mL^-1. The plot of change in the absorption intensity against the logarithm of anti-p53aAbs was linear within 1.0-500.0 ng mL^-1 with a correlation coefficient (R²) of 0.98. The detection limit (LoD) using 3σ was calculated to be 15 pg mL^-1, which is lower than the conventional HRP-label based colorimetric immunoassay. The real sample detection was investigated using the serum recovery method. The recovery of the anti-p53aAbs ranges from 98.5% to 105.7%, demonstrating its potential for practical applications.

Determinants of the efficacy of viro-immunotherapy: A review

Oncolytic virus immunotherapy is rapidly gaining interest in the field of immunotherapy against cancer. The minimal toxicity upon treatment and the dual activity of direct oncolysis and immune activation make therapy with oncolytic viruses (OVs) an interesting treatment modality. The safety and efficacy of several OVs have been assessed in clinical trials and, so far, the Food and Drug Administration (FDA) has approved one OV. Unfortunately, most treatments with OVs have shown suboptimal responses in clinical trials, while they appeared more promising in preclinical studies, with tumours reducing after immune cell influx. In several clinical trials with OVs, parameters such as virus replication, virus-specific antibodies, systemic immune responses, immune cell influx into tumours and tumour-specific antibodies have been studied as predictors or correlates of therapy efficacy. In this review, these studies are summarized to improve our understanding of the determinants of the efficacy of OV therapies in humans and to provide insights for future developments in the viro-immunotherapy treatment field.

Profiling of Naturally Occurring Antibodies to the Thomsen-Friedenreich Antigen in Health and Cancer: The Diversity and Clinical Potential

The Thomsen-Friedenreich (TF) antigen is expressed in a majority of human tumors due to aberrant glycosylation in cancer cells. There is strong evidence that humoral immune response to TF represents an effective mechanism for the elimination of cancer cells that express TF-positive glycoconjugates. The presence of naturally occurring antibodies to tumor-associated TF and cancer-specific changes in their levels, isotype distribution and interrelation, avidity, and glycosylation profile make these Abs a convenient and ubiquitous marker for cancer diagnostics and prognostics. In this review, we attempt to summarize the latest data on the potential of TF-specific Abs for cancer diagnostics and prognostics.

Longitudinal serum autoantibody repertoire profiling identifies surgery-associated biomarkers in lung adenocarcinoma

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Longitudinal sera were globally analyzed for identification of surgery-associated serum biomarker for the first time.

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Autoantibody repertories are stable for a single individual at different time points but highly variable among individuals.

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Surgery-associated serum biomarkers are prevalent in lung adenocarcinoma patients.

Background

Autoantibodies against tumor associated antigens are highly related to cancer progression. Autoantibodies could serve as indicators of tumor burden, and have the potential to monitor the response of treatment and tumor recurrence. However, how the autoantibody repertoire changes in response to cancer treatment are largely unknown.

Methods

Sera of five lung adenocarcinoma patients before and after surgery, were collected longitudinally. These sera were analyzed on a human proteome microarray of 20,240 recombinant proteins to acquire dynamic autoantibody repertoire in response to surgery, as well as to identify the antigens with decreased antibody response after tumor excision or surgery, named as surgery-associated antigens. The identified candidate antigens were then used to construct focused microarray and validated by longitudinal sera collected from a variety of time points of the same patient and a larger cohort of 45 sera from lung adenocarcinoma patients.

Findings

The autoantibody profiles are highly variable among patients. Meanwhile, the autoantibody profiles of the sera from the same patient were surprisingly stable for at least 3 months after surgery. Six surgery-associated antigens were identified and validated. All the five patients have at least one surgery-associated antigen, demonstrating this type of biomarkers is prevalent, while specific antigens are poorly shared among individuals. The prevalence of each antigen is 2%–14% according to the test with a larger cohort.

Interpretation

To our knowledge, this is the first study of dynamically profiling of autoantibody repertoires before/after surgery of cancer patients. The high prevalence of surgery-associated antigens implies the possible broad application for monitoring of tumor recurrence in population, while the low prevalence of specific antigens allows personalized medicine. After the accumulation and analysis of more longitudinal samples, the surgery-associated serum biomarkers, combined as a panel, may be applied to alarm the recurrence of tumor in a personalized manner.

Funding

Research supported by grants from National Key Research and Development Program of China Grant (No. 2016YFA0500600), National Natural Science Foundation of China (No. 31970130, 31600672, 31670831, and 31370813), Open Foundation of Key Laboratory of Systems Biomedicine (No. KLSB2017QN-01), Science and Technology Commission of Shanghai Municipality Medical Guidance Science &Technology Support Project (16411966100), Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant Support (20172005), Shanghai Municipal Commission of Health and Family Planning Outstanding Academic Leaders Training Program (2017BR055) and National Natural Science Foundation of China (81871882).

A specific autoantibody against a novel tumour-association antigen derived from human DNA-topoiomerase I is a potential biomarker for early diagnosis and favourable prognosis in patients with colorectal carcinoma

Context: We previously reported a novel tumour associated antigen (TTA) with molecular weight around 48 kDa and identified the novel TTA as a fragment derived from human DNA-topoiomerase I (TOP1). We termed the novel TAA as TOPO48 and termed autoantibody against the TAA as anti-TOPO48 autoantibody.Objective: To explore the clinical significance of anti-TOPO48 autoantibody in patients with colorectal carcinoma (CRC).Materials and methods: Serum levels of the autoantibody in patients with CRC or benign tumours and healthy volunteers were measured with a specific ELISA.Results: CRC patients at early stage had higher frequency of positive levels of the autoantibody and CRC patients with positive autoantibody levels had higher overall survival rate than those with negative autoantibody levels.Conclusion: The autoantibody is a potential biomarker for early diagnosis and favourable prognosis of CRC.

An autoantibody against a 48-Kd fragment of human DNA-topoiomerase I in breast cancer: Implication for diagnosis and prognosis, and antibody-dependent cellular cytotoxicity in vitro

Previously, we reported a novel tumor-associated antigen (TAA) derived from human DNA-topoiomerase I (TOP 1). In the present study, we demonstrated that the autoantibody against the TAA could be a potential biomarker in the early diagnosis and favorable prognosis of patients with breast cancer (BC). To understand the survival benefits in BC patients, we investigated whether the autoantibody could induce antibody-dependent cellular cytotoxicity activities (ADCC) against breast cancer cells in vitro. We found that the autoantibody exhibited significant ADCC activities that destroyed breast cancer MCF-7 and MDA-MB-231cells with peripheral blood mononuclear cells (PBMCs). The ADCC activities of the autoantibody were significantly correlated with the number of natural killer (NK) cells, NKT cells, and CD4⁺/CD8⁺ T cells. Accordingly, our findings showed that the autoantibody not only represented an early index of immune response to the TAA, but also was involved in host immune defense mechanisms that initiated the destruction of cancer cells.

Improved detection of prostate cancer using a magneto-nanosensor assay for serum circulating autoantibodies

Purpose

To develop a magneto-nanosensor (MNS) based multiplex assay to measure protein and autoantibody biomarkers from human serum for prostate cancer (CaP) diagnosis.

Materials and methods

A 4-panel MNS autoantibody assay and a MNS protein assay were developed and optimized in our labs. Using these assays, serum concentration of six biomarkers including prostate-specific antigen (PSA) protein, free/total PSA ratio, as well as four autoantibodies against Parkinson disease 7 (PARK7), TAR DNA-binding protein 43 (TARDBP), Talin 1 (TLN1), and Caldesmon 1 (CALD1) and were analyzed. Human serum samples from 99 patients (50 with non-cancer and 49 with clinically localized CaP) were evaluated.

Results

The MNS assay showed excellent performance characteristics and no cross-reactivity. All autoantibody assays showed a statistically significant difference between CaP and non-cancer samples except for PARK7. The most significant difference was the combination of the four autoantibodies as a panel in addition to the free/total PSA ratio. This combination had the highest area under the curve (AUC)– 0.916 in ROC analysis.

Conclusions

Our results suggest that this autoantibody panel along with PSA and free PSA have potential to segregate patients without cancer from those with prostate cancer with higher sensitivity and specificity than PSA alone.

Autoantibody-targeted TAAs in pancreatic cancer: A comprehensive analysis

BACKGROUND

Pancreatic cancer is one of the leading causes of cancer mortality and lacks efficient biomarkers for early diagnosis. In the early stages of pancreatic cancer, humoral immunity can respond to a certain amount of tumor-associated antigens (TAAs) with the production of corresponding autoantibodies. Such autoantibody-targeted TAAs (autoTAAs) are highly likely to indicate early events during pancreatic carcinogenesis. Herein, we performed a comprehensive analysis of these autoTAAs to explore their physiological function and their involvement and prognostic value in pancreatic cancer.

METHODS

We first searched the literature to identify the autoTAAs. A PPI network of these autoTAAs was constructed, and core network modules were extracted by Cytoscape software. GO annotation and KEGG pathway analysis were performed to analyze the main physiological functions of these autoTAAs. The prognostic value of autoTAAs in pancreatic cancer was analyzed by using RNA-seq data generated by TCGA.

RESULTS

The PPI network including 98 autoTAAs was constructed, and 2 subgroups were extracted as core modules. GO and KEGG analysis revealed that key functions and pathways of these autoTAAs were significantly enriched in nucleotide repair, protein synthesis, and cancer-associated events. MSH2, EZR, PGK1, VCL and ANXA2 have prognostic value in pancreatic cancer, and high mRNA expression of these 5 proteins is associated with unfavorable prognosis in pancreatic cancer.

CONCLUSIONS

AutoTAAs may be associated with early events in the carcinogenesis of pancreatic cancer. MSH2, EZR, PGK1, VCL and ANXA2 predict poor prognosis in pancreatic cancer. Some autoTAAs also have prognostic value in other cancers.

High similarity of IgG antibody profiles in blood and saliva opens opportunities for saliva based serology

Saliva based diagnostics is a rapidly evolving field due to the large diagnostic potential and simple sample collection. Currently only few individual molecules were investigated for their diagnostic capabilities in saliva. A systematic comparison of IgG antibody profiles in saliva and plasma is still missing in scientific literature. Our hypothesis is that IgG profiles in plasma and saliva are highly similar for each individual. As a consequence, one could implement practically any plasma based IgG assay (classical serology) as saliva based assay. In other words, the IgG antibodies found in blood are also accessible from saliva. We confirm our hypothesis by comparing IgG reactivities towards protein and peptide antigens. We isolated saliva IgG with high purity and demonstrate that plasma IgG reactivities (classical serology) can be inferred from saliva. As a showcase we perform Hepatitis B virus antibody (plasma-)titer determination from saliva. Additionally we show that plasma and saliva IgG profiles of 20 individuals are highly similar for 256 peptide antigens and match (unsupervised) with high probabilities. Finally, we argue for generalisation to the complete IgG antibody profile. The presented findings could contribute greatly to the development of saliva based diagnostic methods of numerous antibody based tests.

Plasma membrane localization of CYP4Z1 and CYP19A1 and the detection of anti-CYP19A1 autoantibodies in humans

It is thought that autoantibody (aAb) production can be caused by (aberrant) protein targeting to the plasma surface of cells. We recently demonstrated the presence of the human cytochrome P450 enzyme CYP4Z1 on the plasma membrane of MCF-7 breast cancer cells and the detection of high titers of anti-CYP4Z1 aAbs in breast cancer patients, but not in healthy controls. In the present study we show that cells of the normal breast cell line MCF-10A do not display CYP4Z1 on their surface. By contrast, we detected CYP19A1 (aromatase) on the plasma membrane of both cell lines. Interestingly, the presence of CYPs on the cell surface did not correlate with their relative expression levels in these cell lines. Indirect ELISA experiments demonstrated the presence of anti-CYP19A1 aAbs in female breast cancer patient sera as well as in male and female controls, respectively; aAb titers in all three groups varied considerably and overall, the results obtained for each group were not significantly different from those of either of the other two groups. Based on these data we propose the hypothesis that CYP translocation to the plasma membrane, but not the intracellular expression level, is the crucial precondition for the generation of anti-CYP aAbs.

Combined detection of serum autoantibodies as diagnostic biomarkers in esophagogastric junction adenocarcinoma

BACKGROUND

We previously found that autoantibodies against a panel of six tumor-associated antigens (p53, NY-ESO-1, MMP-7, Hsp70, PRDX6 and Bmi-1) may aid in early detection of esophageal squamous cell carcinoma. Here we aimed to evaluate the diagnostic value of this autoantibody panel in esophagogastric junction adenocarcinoma (EJA) patients.

METHODS

Serum autoantibody levels were measured by enzyme-linked immunosorbent assay in a training cohort and a validation cohort. We used receiver-operating characteristics (ROC) to calculate diagnostic accuracy.

RESULTS

We recruited 169 normal controls and 122 EJA patients to the training cohort, and 80 normal controls and 70 EJA patients to the validation cohort. Detection of the autoantibody panel demonstrated an area under the curve (AUC) of 0.818, sensitivity 59.0% and specificity 90.5% in training cohort, and AUC 0.815, sensitivity 61.4% and specificity 90.0% in validation cohort in the diagnosis of EJA. Measurement of the autoantibody panel could distinguish early stage EJA patients from normal controls (AUC 0.786 and 0.786, sensitivity 50.0% and 56.0%, and specificity 90.5% and 90.0%, for training and validation cohorts, respectively). Moreover, a restricted panel consisting of autoantibodies against p53, NY-ESO-1 and Bmi-1 exhibited similar diagnostic performance for EJA (AUC 0.814 and 0.823, sensitivity 53.5% and 60.0%, and specificity 90.5% and 93.7%, for training and validation cohorts, respectively) and early stage EJA (AUC 0.744 and 0.773, sensitivity 55.6% and 52.0%, and specificity 90.5% and 93.7%, for training and validation cohorts, respectively).

CONCLUSIONS

Autoantibodies against an optimized TAA panel as serum biomarkers appear to help identify the present of early stage EJA.

Unmet Clinical Need in the Management of Locally Advanced Unresectable Lung Cancer: Treatment Strategies to Improve Patient Outcomes

Stage III locally advanced non-small cell lung cancer (LA NSCLC) comprises the most heterogeneous group of patients, accounts for one-third of patients with lung cancer, and is unresectable at presentation. Multiple treatment approaches have evolved over the past few decades focusing on timing of chemoradiation (concurrent vs. sequential) and sequencing of therapy (induction vs. consolidation). Concurrent chemoradiation (CCRT) emerged as the standard of care for the majority of the patients worldwide. Despite improvements in median and overall survival (OS) using the concurrent approach, the rate of distant failure remains high. Consolidation with chemotherapy or targeted agents, adding more radiation dose, or induction chemotherapy did not improve OS. With continued research on defining optimal radiation doses and schedules and integrating novel systemic agents, immunotherapy consolidation has renewed optimism. Synergistic use of radiation and immunotherapy can prevent micrometastatic disease and reduce local failure and may have an abscopal effect in addition to survival benefits. The PACIFIC study reported an absolute progression-free survival benefit of 11.2 months with durvalumab consolidation after standard CCRT compared with placebo. The OS data with durvalumab consolidation are encouraging. Durvalumab is the only approved immunotherapy for unresectable stage III LA NSCLC. Improved survival confirms the definitive role of durvalumab as an effective adjuvant therapy after CCRT with no new safety signals. However, the potential mechanisms driving interaction between immunotherapy and chemoradiotherapy require definitive investigation. These mechanisms may help define the timing of immunotherapy initiation as neoadjuvant, adjuvant, or consolidation and maintenance therapy after progression. FUNDING: AstraZeneca Pharma India Limited.

Optimizing cancer immunotherapy: Is it time for personalized predictive biomarkers?

Cancer immunotherapy, a treatment that selectively augments a patient's anti-tumor immune response, is a breakthrough advancement in personalized medicine. A subset of cancer patients undergoing immunotherapy have displayed robust and long-lasting therapeutic responses. Currently, the spotlight is on the use of blocking antibodies against the T-cell checkpoint molecules, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programed cell death-1 (PD-1)/programed death-ligand 1 (PD-L1), which have been effectively used to combat many cancers types. Despite the overall enthusiasm, immune checkpoint blockade inhibitors suffer from significant limitations such as high cost, serious toxicity in a substantial proportion of patients, and a response rate as low as 10%-40% in some clinical trials. Consequently, there is an urgent and unmet medical need for companion biomarkers that could both predict the response of individual patients to these therapies, and provide the means for precise monitoring of their therapeutic outcome. In this era of precision medicine, predictive biomarkers are a hot commodity because they can effectively separate responders from non-responders, and spare non-responders from serious therapy-related toxicity. Emerging predictive biomarkers for immune checkpoint blockade are: PD-L1 expression, increased amounts of tumor-infiltrating lymphocytes, increased mutational load and mismatch repair deficiency. Other well-studied biomarkers include inflammatory infiltrate, absolute lymphocyte count and lactate dehydrogenase levels. We review recent progress on predictive cancer biomarkers in immunotherapy, with a special emphasis on serum autoantibodies that have the potential to be personalized for optimal clinical outcomes.

Autoantibody against new gene expressed in prostate protein is traceable in prostate cancer patients

Aim: We assessed an autoantibody against new gene expressed in prostate (NGEP) protein for prostate cancer (PCa) that may better diagnosis and prognosis approaches in the patients with PCa. Methods: Autoantibodies against NGEP were measured in sera of PCa patients by ELISA. Results: The autoantibody against NGEP is present in a significantly higher proportion in the sera of PCa patients as compared with healthy controls (p < 0.001). An inverse significant correlation was found between seropositive patients and Gleason score (p < 0.05) and serum prostate-specific antigen (recombinant NGEP; p < 0.05). Conclusion: The data showed that measurement of autoantibody against NGEP as a novel prostate-specific antigen in sera can be used as a potential biomarker to discriminate well-differentiated PCa patients from normal subjects.

The Thomsen-Friedenreich Antigen-Specific Antibody Signatures in Patients with Breast Cancer

Alterations in the glycosylation of serum total immunoglobulins show these antibodies to have a diagnostic potential for cancer but the disease-related Abs to the tumor-associated antigens, including glycans, have still poorly been investigated in this respect. We analysed serum samples from patients with breast carcinoma (n = 196) and controls (n = 64) for the level of Thomsen-Friedenreich (TF) antigen-specific antibody isotypes, their sialylation, interrelationships, and the avidity by using ELISA with the synthetic TF-polyacrylamide conjugate as an antigen and the sialic acid-specific Sambucus nigra agglutinin (SNA) and ammonium thiocyanate as a chaotrope. An increased sialylation of IgG and IgM, but a lower SNA reactivity of IgA TF antibodies, and a higher level and avidity of the TF-specific IgA were found in cancer patients. Other cancer-related signatures were the highly significant increase of the IgG/IgA ratio and the very low SNA/IgA index in cancer, including patients with an early stage of the disease. These changes showed a good diagnostic potential with about 80% accuracy. Thus, the level of naturally occurring anti-TF antigen antibodies, their sialylation profile, isotype distribution, and avidity displayed cancer-specific changes that could serve as novel noninvasive Ab-based biomarkers for early breast cancer.

Serum anti-TOPO48 autoantibody as a biomarker for early diagnosis and prognosis in patients with esophageal squamous cell carcinoma

BACKGROUND AND AIM

We previously reported a novel tumor associated antigen (TTA) with molecular weight around 48kDa that is a fragment derived from human DNA-topoiomerase I (TOP1). We termed the novel TAA as TOPO48 and termed autoantibody against the TAA as anti-TOPO48 autoantibody. The aim of this study is to further investigate the clinical applications of the autoantibody in patients with esophageal squamous cell carcinomas (ESCC).

METHODS

Serum levels of the anti-TOPO48 autoantibody in 112 ESCC patients, 112 age- and gender-matched healthy controls and 75 patients with esophageal benign tumors were determined by using a specific anti-TOPO48 autoantibody ELISA. Then, we statistically evaluated its clinical significance.

RESULTS

We found that serum anti-TOPO48 autoantibody levels in ESCC patients were significantly higher than that in healthy controls and benign tumor patients (P=0.001). The percentage of sera with a positive level of anti-TOPO48 autoantibody in early stages was significantly higher than that in advanced stages of the cancer patients when the maximum level of healthy control sera was taken as a cut-off value (P=0.001). The area under ROC curve was 0.863 (95% CI=0.797-0.928) for healthy controls vs. early stage ESCC. In addition, patients with positive anti-TOPO48 autoantibody had significantly higher survival rate and longer survival time than that with negative anti-TOPO48 autoantibody in cancer patients (P=0.038, 0.025 and 0.047 for all stages, early stage and advanced stage, respectively).

CONCLUSIONS

Our results suggest that anti-TOPO48 autoantibody may be a potentially useful biomarker for early diagnosis and prognosis of ESCC.

Longitudinal autoantibody responses against tumor-associated antigens decrease in breast cancer patients according to treatment modality

BACKGROUND

Metastatic breast cancer (BCa) is most often diagnosed months after completion of treatment of the primary tumor when a patient reports physical symptoms. Besides a physical examination, no other alternative recurrence screening method is recommended for routine follow-up care. Detection of autoantibodies against tumor-associated antigens (TAAs) has demonstrated promise for distinguishing healthy women from patients diagnosed with primary BCa. However, it is unknown what changes occur to patient autoantibody levels during and after treatment.

METHODS

Three serial blood draws were collected from 200 BCa patients: before treatment, 6 and 12 months after surgery. Patients were categorized according to treatment regimen, including surgery, chemotherapy, radiation, trastuzumab and hormonal therapies. The longitudinal samples were assayed for autoantibody responses against 32 conformation-carrying TAAs using a Luminex multiplex bead assay.

RESULTS

The treatment modality groups that had the greatest decrease in autoantibody response levels were radiation + hormonal therapy; radiation + chemotherapy; and radiation + hormonal therapy + chemotherapy. For these three treatment groups, autoantibody responses against 9 TAAs (A1AT, ANGPTL4, CAPC, CST2, DKK1, GFRA1, GRN, LGALS3 and LRP10) were significantly reduced at 12 months after surgery compared to before treatment. One TAA, GRP78, had a significantly increased autoantibody response after 12 months.

CONCLUSIONS

Single treatment regimens alone did not significantly alter autoantibodies levels against the studied TAAs. Radiation treatment was the common denominator of the three most affected groups for significant changes in autoantibody response levels.

Proteomic profiling of antibody-inducing immunogens in tumor tissue identifies PSMA1, LAP3, ANXA3, and maspin as colon cancer markers

We hypothesized that cancer tissue immunogens - antigens capable of inducing specific antibody production in patients - are promising targets for development of precision diagnostics and humoral immunotherapies. We developed an innovative immuno-proteomic strategy and identified new immunogenic markers of colon cancer. Proteins from cancers and matched normal tissues were separated by 2D gel electrophoresis and blotted with serum antibodies from the same patients. Antibody-reactive proteins were sequenced by mass spectrometry and validated by Western blotting and immunohistochemistry. 170 serum antibody-reactive proteins were identified only in cancerous but not matched normal. Among these, proteasome subunit alpha type 1 (PSA1), leucine aminopeptidase 3 (LAP3), annexin A3 (ANXA3), and maspin (serpin B5) were reproducibly found in tissues from three patients. Differential expression patterns were confirmed in samples from eight patients with various stages of colon adenocarcinoma and liver metastases. These tumor-resident proteins and/or their associated serum antibodies may be promising markers for colon cancer screening and early diagnosis. Furthermore, tumor tissue-specific antibodies could potentially be exploited as immunotherapeutic targets against cancer. More generally, proteomic profiling of antibody-inducing cancer-associated immunogens represents a powerful generic method for uncovering the tumor antigen-ome, i.e., the totality of immunogenic tumor-associated proteins.

Prospective evaluation of 64 serum autoantibodies as biomarkers for early detection of colorectal cancer in a true screening setting

Novel blood-based screening tests are strongly desirable for early detection of colorectal cancer (CRC). We aimed to identify and evaluate autoantibodies against tumor-associated antigens as biomarkers for early detection of CRC. 380 clinically identified CRC patients and samples of participants with selected findings from a cohort of screening colonoscopy participants in 2005–2013 (N=6826) were included in this analysis. Sixty-four serum autoantibody markers were measured by multiplex bead-based serological assays. A two-step approach with selection of biomarkers in a training set, and validation of findings in a validation set, the latter exclusively including participants from the screening setting, was applied. Anti-MAGEA4 exhibited the highest sensitivity for detecting early stage CRC and advanced adenoma. Multi-marker combinations substantially increased sensitivity at the price of a moderate loss of specificity. Anti-TP53, anti-IMPDH2, anti-MDM2 and anti-MAGEA4 were consistently included in the best-performing 4-, 5-, and 6-marker combinations. This four-marker panel yielded a sensitivity of 26% (95% CI, 13–45%) for early stage CRC at a specificity of 90% (95% CI, 83–94%) in the validation set. Notably, it also detected 20% (95% CI, 13–29%) of advanced adenomas. Taken together, the identified biomarkers could contribute to the development of a useful multi-marker blood-based test for CRC early detection.

Identification of novel serum autoantibodies against EID3 in non-functional pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pNETs) are relatively rare heterogenous tumors, comprising only 1–2% of all pancreatic neoplasms. The majority of pNETs are non-functional tumors (NF-pNETs) that do not produce hormones, and as such, do not cause any hormone-related symptoms. As a result, these tumors are often diagnosed at an advanced stage because patients do not present with specific symptoms. Although tumor markers are used to help diagnosis and predict some types of cancers, chromogranin A, a widely used tumor marker of pNETs, has significant limitations. To identify novel NF-pNET-associated antigens, we performed serological identification of antigens by recombinant cDNA expression cloning (SEREX) and identified five tumor antigens (phosphatase and tensin homolog, EP300-interacting inhibitor of differentiation 3 [EID3], EH domain-containing protein 1, galactoside-binding soluble 9, and BRCA1-associated protein). Further analysis using the AlphaLISA^® immunoassay to compare serum antibody levels revealed that antibody levels against the EID3 antigen was significantly higher in the patient group than in the healthy donor group (n = 25, both groups). In addition, higher serum anti-EID3 antibody levels in NF-pNET patients correlated with shorter disease-free survival. The AUC calculated by ROC analysis was 0.784 with moderate diagnostic accuracy. In conclusion, serum anti-EID3 antibody levels may be useful as a tumor marker for prediction of tumor recurrence in NF-pNETs.

Gold-loaded nanoporous iron oxide nanocubes: a novel dispersible capture agent for tumor-associated autoantibody analysis in serum

Autoantibodies are produced against tumor associated antigens (TAAs) long before the appearance of any symptoms and thus can serve as promising, non-invasive biomarkers for early diagnosis of cancer. Current conventional methods for autoantibody detection are highly invasive and mostly provide diagnosis in the later stages of cancer. Herein we report a new electrochemical method for early detection of p53 autoantibodies against colon cancer using a strategy that combines the strength of gold-loaded nanoporous iron oxide nanocube (Au@NPFe₂O₃NC)-based capture and purification while incorporating the inherent simplicity, inexpensive, and portable nature of the electrochemical and naked-eye colorimetric readouts. After the functionalisation of Au@NPFe₂O₃NC with p53 antigens, our method utilises a two-step strategy that involves (i) magnetic capture and isolation of autoantibodies using p53/Au@NPFe₂O₃NC as 'dispersible nanocapture agents' in serum samples and (ii) subsequent detection of autoantibodies through a peroxidase-catalyzed reaction on a commercially available disposable screen-printed electrode or naked-eye detection in an Eppendorf tube. This method has demonstrated a good sensitivity (LOD = 0.02 U mL^-1) and reproducibility (relative standard deviation, %RSD = <5%, for n = 3) for detecting p53 autoantibodies in serum and has also been successfully applied to analyse a small cohort of clinical samples obtained from colorectal cancer. We believe that the highly inexpensive, rapid, sensitive, and specific nature of our assay could potentially aid in the development of an early diagnostic tool for cancer and related diseases.

Protein Array-based Approaches for Biomarker Discovery in Cancer

Biomarkers are deemed to be potential tools in early diagnosis, therapeutic monitoring, and prognosis evaluation for cancer, with simplicity as well as economic advantages compared with computed tomography and biopsy. However, most of the current cancer biomarkers present insufficient sensitivity as well as specificity. Therefore, there is urgent requirement for the discovery of biomarkers for cancer. As one of the most exciting emerging technologies, protein array provides a versatile and robust platform in cancer proteomics research because it shows tremendous advantages of miniaturized features, high throughput, and sensitive detections in last decades. Here, we will present a relatively complete picture on the characteristics and advance of different types of protein arrays in application for biomarker discovery in cancer, and give the future perspectives in this area of research.

Autoantibodies: Opportunities for Early Cancer Detection

Cancer cells can induce an immunological response resulting in the production of tumor-associated (TA) autoantibodies. These serum immunobiomarkers have been detected for a range of cancers at an early stage before the development of clinical symptoms. Their measurement is minimally invasive and cost effective using established technologies. TA autoantibodies are present in a clinically significant number of individuals and could supplement current screening modalities to aid early diagnosis of high-risk populations and assist the clinical management of patients. Here we review their production, discovery, and validation as biomarkers for cancer and their current and future potential as clinical tools.

Autoantibodies against oncogenic ERG protein in prostate cancer: potential use in diagnosis and prognosis in a panel with C-MYC, AMACR and HERV-K Gag

Overdiagnosis and overtreatment of prostate cancer (CaP) is attributable to widespread reliance on PSA screening in the US. This has prompted us and others to search for improved biomarkers for CaP, to facilitate early detection and disease stratification. In this regard, autoantibodies (AAbs) against tumor antigens could serve as potential candidates for diagnosis and prognosis of CaP. Towards this, our goals were: i) To investigate whether AAbs against ERG oncoprotein (overexpressed in 25-50% of Caucasian American and African American CaP) are present in the sera of CaP patients; ii) To evaluate an AAb panel to enhance CaP detection. The results using an enzyme-linked immunosorbent assay (ELISA) showed that anti-ERG AAbs are present in a significantly higher proportion in the sera of CaP patients compared to healthy controls (p = 0.0001). Furthermore, a panel of AAbs against ERG, AMACR and human endogenous retrovirus-K Gag successfully differentiated CaP patient sera from healthy controls (AUC = 0.791). These results demonstrate for the first time that anti-ERG AAbs are present in the sera of CaP patients. In addition, the data also suggest that AAbs against ERG together with AMACR and HERV-K Gag may be a useful panel of biomarkers for diagnosis and prognosis of CaP.

Analysis of histological and immunological parameters of metastatic lymph nodes from colon cancer patients reveals that T-helper 1 type immune response is associated with improved overall survival

Lymph node (LN) involvement in colonic carcinoma (CC) is a grave prognostic sign and mandates the addition of adjuvant treatment. However, in light of the histological variability and outcomes observed, we hypothesized that patients with LN metastases (LNM) comprise different subgroups.We retrospectively analyzed the histological sections of 82 patients with CC and LNM. We studied various histological parameters (such as tumor grade, desmoplasia, and preservation of LN architecture) as well as the prevalence of specific peritumoral immune cells (CD8, CD20, T-bet, and GATA-3). We correlated the histological and immunological data to patient outcome.Tumor grade was a significant prognostic factor even in patients with LNM. So was the number of LN involved (N1/N2 stage). From the morphological parameters tested (LN extracapsular invasion, desmoplasia in LN, LN architecture preservation, and mode of metastases distribution), none was found to be significantly associated with overall survival (OS). The mean OS of CD8 low patients was 66.6 ± 6.25 versus 71.4 ± 5.1 months for CD8 high patients (P = 0.79). However, T-helper (Th) 1 immune response skewing (measured by Th1/Th2 ratio >1) was significantly associated with improved OS. For patients with low ratio, the median OS was 35.5 ± 5 versus 83.5 months for patients with high Th1/Th2 ratio (P = 0.001).The histological presentation of LNM does not entail specific prognostic information. However, the finding of Th1 immune response in LN signifies a protective immune response. Future studies should be carried to verify this marker and develop a strategy that augments this immune response during subsequent adjuvant treatment.

Evaluation of the diagnostic value of 64 simultaneously measured autoantibodies for early detection of gastric cancer

Autoantibodies against tumor-associated antigens (TAAs) have been suggested as biomarkers for early detection of gastric cancer. However, studies that systematically assess the diagnostic performance of a large number of autoantibodies are rare. Here, we used bead-based multiplex serology to simultaneously measure autoantibody responses against 64 candidate TAAs in serum samples from 329 gastric cancer patients, 321 healthy controls and 124 participants with other diseases of the upper digestive tract. At 98% specificity, sensitivities for the 64 tested autoantibodies ranged from 0–12% in the training set and a combination of autoantibodies against five TAAs (MAGEA4 + CTAG1 + TP53 + ERBB2_C + SDCCAG8) was able to detect 32% of the gastric cancer patients at a specificity of 87% in the validation set. Sensitivities for early and late stage gastric cancers were similar, while chronic atrophic gastritis, a precursor lesion of gastric cancer, was not detectable. However, the 5-marker combination also detected 26% of the esophageal cancer patients. In conclusion, the tested autoantibodies and combinations alone did not reach sufficient sensitivity for gastric cancer screening. Nevertheless, some autoantibodies, such as anti-MAGEA4, anti-CTAG1 or anti-TP53 and their combinations could possibly contribute to the development of cancer early detection tests (not necessarily restricted to gastric cancer) when being combined with other markers.

Printed peptide arrays identify prognostic TNC serumantibodies in glioblastoma patients

Liquid biopsies come of age offering unexploited potential to monitor and react to tumor evolution. We developed a cost-effective assay to non-invasively determine the immune status of glioblastoma (GBM) patients. Employing newly developed printed peptide microarrays we assessed the B-cell response against tumor-associated antigens (TAAs) in 214 patients. Firstly, sera of long-term (36+ months, LTS, n=10) and short-term (6-10 months, STS, n=14) surviving patients were screened for prognostic antibodies against 1745 13-mer peptides covering known TAAs (TNC, EGFR, GLEA2, PHF3, FABP5, MAGEA3). Next, survival associations were investigated in two retrospective independent multicenter validation sets (n=61, n=129, all IDH1-wildtype). Reliability of measurements was tested using a second array technology (spotted arrays). LTS/STS screening analyses identified 106 differential antibody responses. Evaluating the Top30 peptides in validation set 1 revealed three prognostic peptides. Prediction of TNC peptide VCEDGFTGPDCAE was confirmed in a second set (p=0.043, HR=0.66 [0.44-0.99]) and was unrelated to TNC protein expression. Median signals of printed arrays correlated with pre-synthesized spotted microarrays (p<0.0002, R=0.33). Multiple survival analysis revealed independence of age, gender, KPI and MGMT status. We present a novel peptide microarray immune assay that identified increased anti-TNC VCEDGFTGPDCAE serum antibody titer as a promising non-invasive biomarker for prolonged survival.

In Vitro Validation of Survivin as Target Tumor-associated Antigen for Immunotherapy in Uterine Cancer

Survivin is an antiapoptotic protein, not expressed in terminally differentiated adult tissues, yet overexpressed in several tumors. Therefore, it is an interesting target for immunotherapeutic strategies. In addition to specific overexpression in tumors, tumor survival is mediated by survivin and hence, tumor survival can be tackled by targeting survivin. Survivin expression in uterine cancer was validated by quantitative real-time polymerase chain reaction and immunohistochemistry. In addition, we evaluated survivin immunogenicity by analyzing spontaneous B-cell and T-cell responses in patients. Survivin as a protein was expressed in only a minority of normal tissues, whereas it was being expressed in all of the currently analyzed uterine cancers, both endometrial carcinoma (n = 52) and uterine sarcoma (n = 52). Survivin RNA transcripts were overexpressed in more aggressive tumors and survivin protein was overexpressed in recurrent endometrial tumors compared with primary tumors. Spontaneous T-cell responses were seen in 10/39 endometrial cancer patients and 3/16 uterine sarcoma patients. In normal controls, T-cell responses were found only in 1 donor (n = 21). Although increased antibody titers were found in more aggressive and far-advanced tumors, no differences in B-cell responses were seen. Overall, when compared with normal controls, a B-cell response was only measured in 1/41 uterine sarcoma patients. In conclusion, we currently validated the presence of survivin in uterine cancer. In addition, spontaneous T-cell responses were found in 23.6% of the total patient population. These data indicate that a survivin-specific immune response may be induced spontaneously in patients, further fortifying the eligibility of survivin as an immunotherapeutic target.

Circulating Anti-Matrix Metalloproteinase-7 Antibodies May Be a Potential Biomarker for Oral Squamous Cell Carcinoma

PURPOSE

The present study was conducted to evaluate the diagnostic and prognostic values of serum autoantibody against matrix metalloproteinase-7 (MMP-7) in patients with oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Anti-MMP-7 antibodies were measured in sera from 204 patients with OSCC and 212 normal controls using enzyme-linked immunosorbent assay, and clinicopathologic characteristics were correlated. Prognostic consequence was assessed with Kaplan-Meier curve and log-rank tests using Cox proportional hazard models. To check whether anti-MMP-7 antibody was related to tumor associated antigen, real-time polymerase chain reaction and western blot were used to measure MMP-7 mRNA and protein expression in tumor tissues from all 204 patients with OSCC.

RESULTS

Serum anti-MMP-7 antibody was higher in patients with OSCC (P < .05), and those with poorly differentiated tumors had more anti-MMP-7 antibody than those with well to moderate tumor differentiation (P < .01, P < .01, respectively). Patients with OSCC at late TNM stages (III, IV) and lymph node metastases had relatively higher serum anti-MMP-7 antibody levels than those with earlier stages (I, II) and those who lacked lymph node metastases (P < .05 for the 2 comparisons). OSCC prediction sensitivity as measured by receiver operating characteristics analysis was 0.485 and specificity was 0.896 (area under the curve, 0.761; 95% confidence interval, 0.716 to 0.806). Cox analysis showed that serum anti-MMP-7 antibody positivity independently predicted poor overall survival in patients with OSCC (hazard ratio, 1.82; 95% confidence interval, 1.07 to 4.61). MMP-7 mRNA and protein expression was increased in tumor tissues from patients with OSCC and high serum anti-MMP-7 antibody.

CONCLUSION

Serum anti-MMP-7 antibody might be a novel diagnostic and prognostic biomarker for OSCC.

Establishment and characterization of a receptor-negative, hormone-nonresponsive breast cancer cell line from an Iraqi patient

A new breast cancer cell line (AMJ13) has been established from an Iraqi breast cancer patient. It is considered unique because it is the first for an Iraqi population, and is expected to be a useful tool in breast cancer research. The AMJ13 cell line was established from the primary tumor of a 70-year-old Iraqi woman with a histological diagnosis of infiltrating ductal carcinoma. The cells were morphologically characterized by light and scanning electron microscopy, and found to be elongated multipolar epithelial-like cells with a population doubling time of 22 hours. The anchorage-independent growth ability test showed that the cells were able to grow in semisolid agarose, confirming their transformed nature. Cytogenetic study of these cells showed chromosomal aberrations with many structural and numerical abnormalities, producing chromosomes of unknown origin called marker chromosomes. Immunocytochemistry showed that the estrogen receptor and the progesterone receptor were not expressed, and a weak positive result was found for HER2/neu gene expression. AMJ13 cells were positive for BRCA1 and BRCA2, as well as for vimentin. This cell line should be useful when testing new therapies for breast cancer in the Middle East.