Immunogenicity of SEREX-identified antigens and disease outcome in pancreatic cancer

Autoantibodies as Potential Liquid Biopsy Biomarker in Detection of Pancreatic Cancer: A Diagnostic Test Accuracy Review and Meta-Analysis

Autoantibodies against tumour-associated antigens (TAA) are promising biomarkers for cancer diagnosis. This systematic review aims to evaluate the diagnostic values of tumour-associated autoantibodies (TAAbs) in patients with pancreatic cancer. A search was conducted in the PubMed, Web of Science, and Embase databases to collect eligible studies. The primary outcomes included sensitivity, specificity, and accuracy of the test. We used QUADAS-2 to evaluate the risk of bias in the included studies. Meta-analysis was performed using MetaDisc 1.4 and STATA 14.0 software to calculate the combined sensitivity and specificity. A total of 49 articles were included in the final analysis that reported over 100 different TAAbs that were studied for the detection of pancreatic cancer. p53, Ezrin, CLDN17, KCNN3, SLAMF7, SLC22A11 and OR51F2 were the most frequently investigated autoantibodies in these studies. Ezrin exhibited better diagnostic performance with the pooled sensitivity, specificity and summary area under the receiver operating characteristic (SROC) curves being 56%, 88% and 0.90, respectively. Moreover, certain autoantibody combinations achieved substantially higher sensitivity at reasonably high levels of specificity. For example, the combination of Ezrin and ENOA1.2 autoantibodies with CA19.9 yielded sensitivity, specificity and area under the SROC curve of 100%, 92% and 0.96, respectively. TAAb is a promising diagnostic biomarker for early detection of PC, especially when combining TAAb with other markers. The promising candidate markers identified in this review deserve further validation in a broad screening population.

B cell clonality in cancer

Carcinogenesis in the process of long-term co-evolution of tumor cells and immune environment essentially becomes possible due to incorrect decisions made, remembered, and reproduced by the immune system at the level of clonal populations of antigen-specific T- and B-lymphocytes. Tumor-immunity interaction determines the nature of such errors and, consequently, delineates the possible ways of successful immunotherapeutic intervention. It is generally recognized that tumor-infiltrating B cells (TIL-B) can play both pro-tumor and anti-tumor roles. However, the exact mechanisms that determine the contribution of clonal B cell lineages with different specificities and functions remain largely unclear. This is due to the variability of cancer types, the molecular heterogeneity of tumor cells, and, to a large extent, the individual pattern of each immune response. Further progress requires detailed investigation of the functional properties and phenotypes of clonally heterogeneous B cells in relation to their antigenic specificities, which determine the functionality of both effector B lymphocytes and immunoglobulins produced in the tumor environment. Based on a real understanding of the role of clonal antigen-specific populations of B lymphocytes in the tumor microenvironment, we need to learn how to develop new methods of targeted immunotherapy, as well as adapt existing treatment options to the specific needs of different patients and patient subgroups. In this review, we will cover B cells functional diversity and their multifaceted roles in the tumor environment.

Serum Anti-BRAT1 is a Common Molecular Biomarker for Gastrointestinal Cancers and Atherosclerosis

Atherosclerosis (AS) and cancers are major global causes of mortality and morbidity. They also share common modifiable pathogenesis risk factors. As the same strategies used to predict AS could also detect certain cancers, we sought novel serum antibody biomarkers of cancers in atherosclerotic sera sampled by liquid biopsy. Using serological antigen identification by cDNA expression cloning (SEREX) and western blot, we screened and detected the antigens BRCA1-Associated ATM Activator 1 (BRAT1) and WD Repeat Domain 1 (WDR1) in the sera of patients with transient ischemic attacks (TIA). Amplified luminescence proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) established the upregulation of serum BRAT1 antibody (BRAT1-Abs) and WDR1 antibody (WDR1-Abs) in patients with AS-related diseases compared with healthy subjects. ROC and Spearman’s correlation analyses showed that BRAT1-Abs and WDR1-Abs could detect AS-related diseases. Thus, serum BRAT1-Abs and WDR1-Abs are potential AS biomarkers. We used online databases and AlphaLISA detection to compare relative antigen and serum antibody expression and found high BRAT1 and BRAT1-Abs expression in patients with GI cancers. Significant increases (> 0.6) in the AUC for BRAT1-Ab vs. esophageal squamous cell carcinoma (ESCC), gastric cancer, and colorectal cancer suggested that BRAT1-Ab exhibited better predictive potential for GI cancers than WDR1-Ab. There was no significant difference in overall survival (OS) between BRAT1-Ab groups (P = 0.12). Nevertheless, a log-rank test disclosed that the highest serum BRAT1-Ab levels were associated with poor ESCC prognosis at 5–60 weeks post-surgery. We validated the foregoing conclusions by comparing serum BRAT1-Ab and WDR1-Ab levels based on the clinicopathological characteristics of the patients with ESCC. Multiple statistical approaches established a correlation between serum BRAT1-Ab levels and platelet counts. BRAT1-Ab upregulation may enable early detection of AS and GI cancers and facilitate the delay of disease progression. Thus, BRAT1-Ab is a potential antibody biomarker for the diagnosis of AS and GI cancers and strongly supports the routine clinical application of liquid biopsy in chronic disease detection and diagnosis.

Human Retrotransposons and the Global Shutdown of Homeostatic Innate Immunity by Oncolytic Parvovirus H-1PV in Pancreatic Cancer

Although the oncolytic parvovirus H-1PV has entered clinical trials, predicting therapeutic success remains challenging. We investigated whether the antiviral state in tumor cells determines the parvoviral oncolytic efficacy. The interferon/interferon-stimulated genes (IFN/ISG)-circuit and its major configurator, human endogenous retroviruses (HERVs), were evaluated using qRT-PCR, ELISA, Western blot, and RNA-Seq techniques. In pancreatic cancer cell lines, H-1PV caused a late global shutdown of innate immunity, whereby the concomitant inhibition of HERVs and IFN/ISGs was co-regulatory rather than causative. The growth-inhibitory IC50 doses correlated with the power of suppression but not with absolute ISG levels. Moreover, H-1PV was not sensitive to exogenous IFN despite upregulated antiviral ISGs. Such resistance questioned the biological necessity of the oncotropic ISG-shutdown, which instead might represent a surrogate marker for personalized oncolytic efficacy. The disabled antiviral homeostasis may modify the activity of other viruses, as demonstrated by the reemergence of endogenous AluY-retrotransposons. This way of suppression may compromise the interferogenicity of drugs having gemcitabine-like mechanisms of action. This shortcoming in immunogenic cell death induction is however amendable by immune cells which release IFN in response to H-1PV.

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.

A systematic review of serum autoantibodies as biomarkers for pancreatic cancer detection

Pancreatic cancer is a leading cause of cancer-related deaths in the western world. Patients with pancreatic cancer have poor prognosis, partly due to difficulties in detecting it at early stages. While different markers have been associated with pancreatic cancer, many of them show suboptimal sensitivity and specificity. Serum autoantibodies against tumor-associated antigens have recently emerged as early stage biomarkers for different types of cancers. Given the urgent need for early and reliable biomarkers for pancreatic cancer, we undertook a systematic review of the published literature to identify primary articles that evaluated serum autoantibodies in pancreatic cancer detection by searching PubMed and ISI Web of Knowledge. Two reviewers extracted data on study characteristics and results independently. Overall, 31 studies evaluating 124 individual serum autoantibodies in pancreatic cancer detection met the inclusion criteria. In general, single autoantibody markers showed relatively low sensitivities at high specificity. A combination of markers, either multiple serum autoantibodies or serum autoantibodies combined with tumor-associated markers, led to a better diagnostic performance. However, most of the analyzed autoantibodies have only been reported in single studies and therefore need to be independently validated. We conclude that serum autoantibodies might present an option as biomarkers for early detection of pancreatic cancer, but more work is needed to identify and validate autoantibody signatures that are associated with early stage pancreatic cancer.

Combination of mAb-AR20.5, anti-PD-L1 and PolyICLC inhibits tumor progression and prolongs survival of MUC1.Tg mice challenged with pancreatic tumors

A substantial body of evidence suggests the existence of MUC1-specific antibodies and cytotoxic T cell activities in pancreatic cancer patients. However, tumor-induced immunosuppression renders these responses ineffective. The current study explores a novel therapeutic combination wherein tumor-bearing hosts can be immunologically primed with their own antigen, through opsonization with a tumor antigen-targeted antibody, mAb-AR20.5. We evaluated the efficacy of immunization with this antibody in combination with PolyICLC and anti-PD-L1. The therapeutic combination of mAb-AR20.5 + anti-PD-L1 + PolyICLC induced rejection of human MUC1 expressing tumors and provided a long-lasting, MUC1-specific cellular immune response, which could be adoptively transferred and shown to provide protection against tumor challenge in human MUC1 transgenic (MUC.Tg) mice. Furthermore, antibody depletion studies revealed that CD8 cells were effectors for the MUC1-specific immune response generated by the mAb-AR20.5 + anti-PD-L1 + PolyICLC combination. Multichromatic flow cytometry data analysis demonstrated a significant increase over time in circulating, activated CD8 T cells, CD3⁺CD4^-CD8^-(DN) T cells, and mature dendritic cells in mAb-AR20.5 + anti-PD-L1 + PolyICLC combination-treated, tumor-bearing mice, as compared to saline-treated control counterparts. Our study provides a proof of principle that an effective and long-lasting anti-tumor cellular immunity can be achieved in pancreatic tumor-bearing hosts against their own antigen (MUC1), which can be further potentiated using a vaccine adjuvant and an immune checkpoint inhibitor.

The roles and applications of autoantibodies in progression, diagnosis, treatment and prognosis of human malignant tumours

The existence of autoantibodies towards an individual's own proteins or nucleic acids has been established for more than 100years, and for a long period, these autoantibodies have been believed to be closely associated with autoimmune diseases. However, in recent years, researchers have become more interested in the role and application of autoantibodies in progression, diagnosis, treatment and prognosis of human malignant tumours. Over the past few decades, numerous epidemiological studies have shown that the risk of certain cancers is significantly altered (increased or decreased) in patients with autoimmune diseases, which suggests that autoantibodies may play either promoting or suppressing roles in cancer progression. The idea that autoantibodies are directly involved in tumour progression gains special support by the findings that some antibodies secreted by a variety of cancer cells can promote their proliferation and metastasis. Because the cancer cells generate cell antigenic changes (neoantigens), which trigger the immune system to produce autoantibodies, serum autoantibodies against tumour-associated antigens have been established as a novel type of cancer biomarkers and have been extensively studied in different types of cancer. The autoantibodies as biomarkers in cancer diagnosis are not only more sensitive and specific than antigens, but also could appear before clinical evidences of the tumours, thus disclosing them. The observations that cancer risk is lower in patients with some autoimmune diseases suggest that certain autoantibodies may be protective from certain cancers. Moreover, the presence of autoantibodies in healthy individuals implies that it could be safe to employ autoantibodies to treat cancer. Of note, an autoantibodies derived from lupus murine model received much attention due to their selective cytotoxicity for malignant tumour cell without harming normal ones. These studies showed the therapeutic value of autoantibodies in cancer. In this review, we revisited the pathological or protective role of autoantibodies in cancer progression, summarize the application of autoantibodies in cancer diagnosis and prognosis, and discuss the value of autoantibodies in cancer therapy. The studies established to date suggest that autoantibodies not only regulate cancer progression but also promise to be valuable instruments in oncological diagnosis and therapy.

Establishment and Characterization of a Novel Cell Line, ASAN-PaCa, Derived From Human Adenocarcinoma Arising in Intraductal Papillary Mucinous Neoplasm of the Pancreas

OBJECTIVES

Our aim was to establish and characterize a novel pancreatic ductal adenocarcinoma cell line from a patient in whom the origin of the invasive carcinoma could be traced back to the intraductal papillary mucinous neoplasm (IPMN) precursor lesion.

METHODS

The primary patient-derived tumor was propagated in immunocompromised mice for 2 generations and used to establish a continuous in vitro culture termed ASAN-PaCa. Transplantation to fertilized chicken eggs confirmed the tumorigenic potential in vivo. Molecular analyses included karyotyping, next-generation genomic sequencing, expression analysis of marker proteins, and mucin-profiling.

RESULTS

The analysis of marker proteins confirmed the epithelial nature of the established cell line, and revealed that the expression of the mucin MUC1 was higher than that of MUC2 and MUC5AC. ASAN-PaCa cells showed rapid in vitro and in vivo growth and multiple chromosomal aberrations. They harbored mutations in KRAS (Q61H), TP53 (Y220C), and RNF43 (I47V and L418M) but lacked either IPMN-specific GNAS or presumed pancreatic ductal adenocarcinoma-driving mutations in KRAS (codons 12/13), SMAD, and CDKN2A genes.

CONCLUSIONS

ASAN-PaCa cell line represents a novel preclinical model of pancreatic adenocarcinoma arising in the background of IPMN, and offers an opportunity to study how further introduction of known driver mutations might contribute to pancreatic carcinogenesis.

Peripheral ENO1-specific T cells mirror the intratumoral immune response and their presence is a potential prognostic factor for pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with an average survival of 4-6 months following diagnosis. Surgical resection is the only treatment with curative intent, but resectable PDAC patients are in the minority. Also, unlike other neoplasms, PDAC is resistant to conventional and targeted chemotherapy. Innovative treatments, such as immunotherapy, can be very important and the study of the immune response is fundamental. We previously demonstrated that PDAC patients show tumor-infiltrating T cells specific to α-enolase (ENO1), a glycolytic enzyme over-expressed by pancreatic tumor cells, which plays an important role in promoting cell migration and cancer metastasis. In the present study, we evaluate the functional anticancer proprieties of ENO1-specific T cells isolated from the peripheral blood of PDAC patients. Furthermore, comparing the T cell receptor repertoire of ENO1-specific peripheral and infiltrating tumor T cells from the same patient suggests that ENO1-specific T cells, despite having a different functional profile, can recirculate from the tumor to the periphery. Finally, of clinical relevance, the presence of peripheral ENO1-specific T cells has a prognostic value and significantly correlates with a longer survival.

Transcriptional co-factor Transducin beta-like (TBL) 1 acts as a checkpoint in pancreatic cancer malignancy

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer fatalities in Western societies, characterized by high metastatic potential and resistance to chemotherapy. Critical molecular mechanisms of these phenotypical features still remain unknown, thus hampering the development of effective prognostic and therapeutic measures in PDAC. Here, we show that transcriptional co-factor Transducin beta-like (TBL) 1 was over-expressed in both human and murine PDAC. Inactivation of TBL1 in human and mouse pancreatic cancer cells reduced cellular proliferation and invasiveness, correlating with diminished glucose uptake, glycolytic flux, and oncogenic PI3 kinase signaling which in turn could rescue TBL1 deficiency-dependent phenotypes. TBL1 deficiency both prevented and reversed pancreatic tumor growth, mediated transcriptional PI3 kinase inhibition, and increased chemosensitivity of PDAC cells in vivo. As TBL1 mRNA levels were also found to correlate with PI3 kinase levels and overall survival in a cohort of human PDAC patients, TBL1 was identified as a checkpoint in the malignant behavior of pancreatic cancer and its expression may serve as a novel molecular target in the treatment of human PDAC.

Stratification of pancreatic tissue samples for molecular studies: RNA-based cellular annotation procedure

BACKGROUND/OBJECTIVES

Meaningful profiling of pancreatic cancer samples is particularly challenging due to their complex cellular composition. Beyond tumor cells, surgical biopsies contain desmoplastic stroma with infiltrating inflammatory cells, adjacent normal parenchyma, and "non-pancreatic tissues". The risk of misinterpretation rises when the heterogeneous cancer tissues are sub-divided into smaller fragments for multiple analytic procedures. Pre-analytic histological evaluation is the best option to characterize pancreatic tissue samples. Our aim was to develop a complement or alternative procedure to determine the cellular composition of pancreatic cancerous biopsies, basing on intra-analytic molecular annotation. A standard process for sample stratification at a molecular level does not yet exist. Particularly in the case of retrospective or data depository-based studies, when hematoxylin-eosin stained sections are not available, it supports the correct interpretation of expression profiles.

METHODS

A five-gene transcriptional signature (RNACellStrat) was defined that allows cell type-specific stratification of pancreatic tissues. Testing biopsy material from biobanks with this procedure demonstrated high correspondence of molecular (qRT-PCR and microarray) and histologic (hematoxylin-eosin stain) evaluations.

RESULTS

Notably, about a quarter of randomly selected samples (tissue fragments) were exposed as inappropriate for subsequent clinico-pathological interpretation.

CONCLUSIONS

Via immediate intra-analytical procedure, our RNA-based stratification RNACellStrat increases the accuracy and reliability of the conclusions drawn from diagnostic and prognostic molecular information.

Current and future intratumoral targeted treatment for pancreatic cancer

Pancreatic cancer is an insidious type of cancer with its symptoms manifested upon extensive disease. The overall 5-year survival rates between 0.4 and 4%. Surgical resection is an option for only 10% of the patients with pancreatic cancer. Local recurrence and hepatic metastases occur within 2 years after surgery. There are currently several molecular pathways investigated and novel targeted treatments are on the market. However; the nature of pancreatic cancer with its ability to spread locally in the primary site and lymph nodes indicates that further experimentation with local interventional therapies could be a future treatment proposal as palliative care or adjunct to gene therapy and chemotherapy/radiotherapy. In the current review, we will summarize the molecular pathways and present the interventional treatment options for pancreatic cancer.

Novel pancreatic cancer vaccines could unleash the army within

BACKGROUND

Despite recent progress with novel chemotherapy regimens, pancreatic ductal adenocarcinoma remains the fourth leading cause of cancer death in the United States. Innovative approaches to treatment of this disease are needed to accelerate progress.

METHODS

A review was conducted of the results of 2 pancreatic cancer vaccine programs with results that have shown promise in early-phase clinical trials.

RESULTS

In a phase 2 trial, a cell-based allogeneic pancreatic cancer vaccine exploiting the hyperacute rejection response targeted against alpha-1,3 galactosyl epitopes (algenpantucel-L) has shown improvement in disease-free and overall survival rates in the adjuvant setting compared with a historical control. This vaccine has advanced to ongoing phase 3 trials. Compared with GVAX alone, a second whole-cell vaccine employing GM-CSF-expressing pancreatic cancer cells (GVAX) to enhance the antigen presentation in a priming phase followed by a Listeria-based vaccine targeting mesothelin in a boost phase improved survival rates. This vaccine platform is undergoing additional phase 2 testing.

CONCLUSIONS

Allogenic whole-cell pancreatic adenocarcinoma vaccines show promise in early-phase trials and have the potential to improve survival rates by unleashing antitumor immunity.

The complex landscape of pancreatic cancer metabolism

Pancreatic ductal adenocarcinomas (PDA) are extremely aggressive cancers and currently available therapies are only minimally effective in treating this disease. Tackling this devastating cancer has been a major challenge to the scientific and medical communities, in part due to its intense therapeutic resistance. One of the aspects of this tumor that contributes to its aggressive behavior is its altered cellular metabolism. Indeed, PDA cells seem to possess the ability to adapt their metabolism to the particular environment to which they are exposed, including utilizing diverse fuel sources depending on their availability. Moreover, PDA tumors are efficient at recycling various metabolic substrates through activation of different salvage pathways such as autophagy and macropinocytosis. Together, these diverse metabolic adaptations allow PDA cells to survive and thrive in harsh environments that may lack nutrients and oxygen. Not surprisingly, given its central role in the pathogenesis of this tumor, oncogenic Kras plays a critical role in much of the metabolic reprogramming seen in PDA. In this review, we discuss the metabolic landscape of PDA tumors, including the molecular underpinnings of the key regulatory nodes, and describe how such pathways can be exploited for future diagnostic and therapeutic approaches.

Two immune faces of pancreatic adenocarcinoma: possible implication for immunotherapy

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive human neoplasms, having extremely poor prognosis with a 5-year survival rate of <1 % and a median survival of 6 months. In contrast to other malignancies, pancreatic cancer is highly resistant to chemotherapy and targeted therapy. Therefore, new treatment options are urgently needed to improve the survival of patients with PDAC. Based on our data showing that patients with higher CD8+ T cell tumour infiltration exhibited prolonged overall and disease-free survival compared to patients with lower or without CD8+ T cell tumour infiltration, we suggested that immunotherapy could be a promising treatment option for PDAC. However, clinical data from the chemoradioimmunotherapy with interferon-α (IFN) trial did not point to an improved efficiency of chemoradiation combined with IFN as compared to chemoradiotherapy alone, suggesting an important role of the immune suppression induced by PDAC and/or unspecific immune stimulation. In support of this hypothesis, we found that the PDAC patients and experimental mice had an increased number of regulatory T cells and myeloid-derived suppressor cells. These results allowed us to conclude that PDAC provokes not only an anti-tumour immune response, but also strong immune suppression. Thus, we supposed that new immunotherapeutical strategies should involve not only stimulation of the immune system of PDAC patients, but also exert control over the tumour immune suppressive milieu.

Serological identification of URGCP as a potential biomarker for glioma

AIM

Glioblastoma multiforme (GBM) is one of the most frequent human brain tumor and causes dismal outcome. To identify tumor-associated antigens in GBM patients may find potential diagnostic markers and immunotherapeutic targets. In this study, we identified a gene termed URGCP using the serological identification of antigens by recombinant A2B5 positive glioma cDNA library. The gene product of URGCP is immunogenic in GBM after tested in allogenic patients serum screening.

METHODS AND RESULTS

GBM patients with an auto-antibody response against URGCP show longer survival than those without URGCP response. In additional, we show that URGCP was high expression in most GBM tissues and cell lines compared with normal brain tissues and majorly co-expressed with stem cell marker A2B5.

CONCLUSION

We identified a potential new biomarker of GBM, URGCP. The findings indicate that URGCP is immunogenic in human GBM and suggest its potential use as diagnostic and immunotherapeutic for GBM patients.

Early epigenetic downregulation of WNK2 kinase during pancreatic ductal adenocarcinoma development

Pancreatic ductal adenocarcinoma (PDAC) is usually incurable. Contrary to genetic mechanisms involved in PDAC pathogenesis, epigenetic alterations are ill defined. Here, we determine the contribution of epigenetically silenced genes to the development of PDAC. We analyzed enriched, highly methylated DNAs from PDACs, chronic pancreatitis (CP) and normal tissues using CpG island microarrays and identified WNK2 as a prominent candidate tumor suppressor gene being downregulated early in PDAC development. WNK2 was further investigated in tissue microarrays, methylation analysis of early pancreatic intraepithelial neoplasia (PanIN), mouse models for PDAC and pancreatitis, re-expression studies after demethylation, and cell growth assays using WNK2 overexpression. Demethylation assays confirmed the link between methylation and expression. WNK2 hypermethylation was higher in tumor than in surrounding inflamed tissues and was observed in PanIN lesions as well as in a PDAC mouse model. WNK2 mRNA and protein expressions were lower in PDAC and CP compared with normal tissues both in patients and mouse models. Overexpression of WNK2 led to reduced cell growth, and WNK2 expression in tissues correlated negatively with pERK1/2 expression, a downstream target of WNK2 responsible for cell proliferation. Downregulation of WNK2 by promoter hypermethylation occurs early in PDAC pathogenesis and may support tumor cell growth via the ERK-MAPK pathway.

Overcoming immunosuppression as a new immunotherapeutic approach against pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest types of malignancy. Via a broad stimulation of the immune system, PDAC activates both antitumor immune responses and immunosuppressive mechanisms. We propose that new immunotherapeutic strategies for the management of PDAC should be designed to specifically neutralize the immunosuppressive tumor microenvironment.

Autoantibody against WD repeat domain 1 is a novel serological biomarker for screening of thyroid neoplasia

BACKGROUND

Thyroid nodules are common among adults, and accurate diagnosis is critical in for management decisions. Ultrasound and fine needle aspiration cytology are the most common methods to evaluate nodules, but they are not practical for screening large numbers of patients because of cost and time considerations.

OBJECTIVE

The aim of this study was to isolate an autoantibody to tumour antigen, WD repeat domain 1 (WDR1), and evaluate its diagnostic sensitivity and specificity for thyroid neoplasms.

PATIENTS AND METHODS

We investigated serological biomarkers in patients with thyroid carcinoma who had a poor prognosis. Using a serological analysis of recombinant cDNA expression cloning (SEREX) strategy, we isolated WDR1 and its specific autoantibody in the sera of patients with undifferentiated thyroid carcinoma (UTC). We examined using indirect ELISA, the titre of the anti-WDR1 antibody (AWA) in 54 study patients: 10 with UTC, 20 with papillary thyroid carcinoma (PTC), 17 with benign thyroid nodule (BTN), 7 with autoimmune thyroid disease (AITD), as well as 38 controls (N).

RESULTS

WDR1 was ubiquitously expressed in various types of thyroid tissues. However, the titre of AWA in UTC and PTC was significantly higher than that in BTN, AITD and N (P < 0·001). No significant correlation was observed between thyroid function, serum thyroglobulin and tumour diameter. The cut-off value estimated using ROC to differentiate malignancies from others was 0·95 (sensitivity 96·7%, specificity 91·9%, AUC 0·969, P < 0·001).

CONCLUSIONS

Anti-WDR1 antibody could be a novel approach for serological screening of PTC and UTC, and could be an efficient and inexpensive biomarker.

Tumor-associated autoantibodies as diagnostic and prognostic biomarkers

In the process of tumorigenesis, normal cells are remodeled to cancer cells and protein expression patterns are changed to those of tumor cells. A newly formed tumor microenvironment elicits the immune system and, as a result, a humoral immune response takes place. Although the tumor antigens are undetectable in sera at the early stage of tumorigenesis, the nature of an antibody amplification response to antigens makes tumor-associated autoantibodies as promising early biomarkers in cancer diagnosis. Moreover, the recent development of proteomic techniques that make neo-epitopes of tumor-associated autoantigens discovered concomitantly has opened a new area of ‘immuno-proteomics’, which presents tumor-associated autoantibody signatures and confers information to redefine the process of tumorigenesis. In this article, the strategies recently used to identify and validate serum autoantibodies are outlined and tumor-associated antigens suggested until now as diagnostic/prognostic biomarkers in various tumor types are reviewed. Also, the meaning of autoantibody signatures and their clinical utility in personalized medicine are discussed. [BMB Reports 2012; 45(12): 677-685]

High-throughput screening for native autoantigen-autoantibody complexes using antibody microarrays

We report on a novel, high-dimensional method to detect autoantibodies that are complexed with their natural autoantigens. Specifically, autoantibody-autoantigen complexes in serum or plasma are directly incubated onto a high-density antibody microarray. Detection of the bound autoantibody-antigen complex is made via fluorescently labeled antihuman immunoglobulin G or other immunoglobulin isotype secondary antibodies and quantification in a microarray scanner. Uncomplexed antibodies do not interfere with this assay. The whole process is very rapid and applicable for high-throughput screening without the need for production of proteins or immunoglobulin purification from the samples. Using these methods, we found that plasma from healthy individuals contains hundreds of autoantibodies complexed with cellular proteins. Thus, this highly sensitive, multiplex method is capable of discovering new autoantibody-antigen or circulating immune complexes, many of which will likely be useful for disease detection and characterization.

Serum autoantibodies to pancreatic cancer antigens as biomarkers of pancreatic cancer in a San Francisco Bay Area case-control study

BACKGROUND

Screening and early diagnosis tools are lacking for pancreatic adenocarcinoma; most patients are diagnosed with metastatic disease. Autoantibodies to tumor-associated antigens (TAAs) can be present months to years before diagnosis and hold promise as biomarkers for early detection.

METHODS

TAAs to pancreatic cancer autoantibodies CTDSP1 (carboxy-terminal domain, RNA polymerase II, polypeptide A, small phosphatase 1), MAPK9 (mitogen-activated protein kinase 9), and NR2E3 (nuclear receptor subfamily 2, group E, member 3), which were identified as potentially promising biomarkers in exploratory studies, were evaluated in serum from participants (300 cases, 300 controls) in a population-based case-control pancreatic cancer study in the San Francisco Bay Area. Patients were identified through cancer registry rapid case ascertainment, newly diagnosed from 1995 to 1999 and followed up through 2008. Autoantibody levels were analyzed as continuous and grouped (quartiles) variables. Multivariable unconditional logistic regression was used to compute odds ratios (ORs) as estimates of autoantibody levels associated with disease status. Kaplan-Meier product limit estimates and multivariable Cox proportional hazards regression were used to assess autoantibody levels associated with case survival duration.

RESULTS

Cases had higher levels of CTDSP1 (P = .004), MAPK9 (P = .0002), and NR2E3 (P ≤ .0001) autoantibodies than controls (fourth vs first quartile: CTDSP1 OR = 1.7, MAPK9 OR = 2.5, NR2E3 OR = 4.0). High body mass index and tobacco use were associated with levels in controls but were not statistical confounders. High CTDSP1 levels were somewhat associated with better survival (hazard ratio = 0.77, P = .07).

CONCLUSIONS

Combined with previous results, this study contributes evidence that cancer-related host immune-response factors may be useful diagnostic screening tools and prognostic indicators for pancreatic cancer. Further studies are needed to critically assess the value of autoantibody panels to TAAs in diagnostic screening, prognosis, and immunotherapy of pancreatic and other cancers.