Clinical utility of anti-p53 auto-antibody: Systematic review and focus on colorectal cancer

Serum BRD2 autoantibody in hepatocellular carcinoma and its detection using mimotope peptide‑conjugated BSA

Tumor‑associated (TA) autoantibodies are considered to be promising biomarkers for the early detection of cancer, prior to the development of clinical symptoms. In the present study, a novel TA autoantibody was detected, which may prove to be useful as a diagnostic marker of human HCC using an HBx‑transgenic (HBx‑tg) hepatocellular carcinoma (HCC) mouse model. Its target antigen was identified as the bromodomain‑containing protein 2 (BRD2), a transcriptional regulator that plays a pivotal role in the transcriptional control of diverse genes. BRD2 was upregulated in HCC tissues of the H‑ras12V‑tg mouse and human subjects, as demonstrated using western blotting or immunohistochemical analysis, with the BRD2 autoantibody. In addition, the truncated BRD2 reactive to the BRD2 autoantibody was detected in tumor cell‑derived exosomes, which possibly activated TA immune responses and the generation of autoantibodies. For the detection of the serum BRD2 autoantibody, epitope mimicries of autoantigenic BRD2 were screened from a random cyclic peptide CX₇C library with the BRD2 autoantibody. A mimotope with the sequence of CTSVFLPHC, which was cyclized by one pair of cysteine residues, exhibited high affinity to the BRD2 autoantibody and competitively inhibited the binding of the autoantibody to the cellular BRD2 antigen. The use of this cyclic peptide as a capture antigen in human serum enzyme‑linked immunosorbent assay allowed the distinction of patients with HCC from healthy subjects with 64.41% sensitivity and 82.42% specificity (area under the ROC curve, 0.7761), which is superior to serum alpha‑fetoprotein (AFP; 35.83% sensitivity; 100% specificity; area under the ROC curve, 0.5337) for the diagnosis of HCC. In addition, the detection of the BRD2 autoantibody combined with other autoantibody biomarkers or AFP has increased the accuracy of HCC diagnosis, suggesting that the combinational detection of cancer biomarkers, including the BRD2 autoantibody, is a promising assay for HCC diagnosis.

Prospective Proteomic Study Identifies Potential Circulating Protein Biomarkers for Colorectal Cancer Risk

Simple Summary

Studies on circulating protein for colorectal cancer risk in a prospective study design is lacking. The aim of the present study was to scan and identify the protein markers by using proteomics technologies in a two-stage case-control study nested within the Shanghai Women’s Health Study (SWHS), a population-based prospective cohort study. In the discovery set, we found 27 circulating proteins with a nominally significant association. Six of them, including CD79B, DDR1, EFNA4, FLRT2, LTA4H, and NCR1, were validated in the validation phase of the study. This study is the first to evaluate over 1000 circulating proteins in prediagnostic blood samples for their associations with CRC risk in East Asians.

Abstract

Background: Proteomics-based technologies are emerging tools used for cancer biomarker discovery. Limited prospective studies have been conducted to evaluate the role of circulating proteins in colorectal cancer (CRC) development. Methods: A two-stage case-control proteomics study nested in the Shanghai Women’s Health Study was conducted. A total of 1104 circulating proteins were measured in the discovery phase, consisting of 100 incident CRC cases and 100 individually matched controls. An additional 60 case-control pairs were selected for validation. Protein profiling at both stages was completed using the Olink platforms. Conditional logistic regression was used to evaluate the associations between circulating proteins and CRC risk. The elastic net method was employed to develop a protein score for CRC risk. Results: In the discovery set, 27 proteins showed a nominally significant association with CRC risk, among which 22 were positively and 5 were inversely associated. Six of the 27 protein markers were significantly associated with CRC risk in the validation set. In the analysis of pooled discovery and validation sets, odds ratios (ORs) per standard deviation (SD) increase in levels of these proteins were 1.54 (95% confidence interval (CI): 1.15–2.06) for CD79B; 1.71 (95% CI: 1.24–2.34) for DDR1; 2.04 (95% CI: 1.39–3.01) for EFNA4; 1.54 (95% CI: 1.16–2.02) for FLRT2; 2.09 (95% CI: 1.47–2.98) for LTA4H and 1.88 (95% CI: 1.35–2.62) for NCR1. Sensitivity analyses showed consistent associations for all proteins with the exclusion of cases diagnosed within the first two years after the cohort enrollment, except for CD79B. Furthermore, a five-protein score was developed based on the six proteins identified and showed significant associations with CRC risk in both discovery and validation sets (Discovery: OR_1-SD = 2.46, 95% CI: 1.53–3.95; validation: OR_1-SD = 4.16, 95% CI: 1.92–8.99). Conclusions: A panel of five protein markers was identified as potential biomarkers for CRC risk. Our findings provide novel insights into the etiology of CRC and may facilitate the risk assessment of the malignancy.

Cerium oxide-doped PEDOT nanocomposite for label-free electrochemical immunosensing of anti-p53 autoantibodies

A label-free nanoimmunosensor is reported based on p53/CeO₂/PEDOT nanobiocomposite-decorated screen-printed gold electrodes (SPAuE) for the electrochemical detection of anti-p53 autoantibodies. CeO₂ nanoparticles (NPs) were synthesized and stabilized with cyanopropyltriethoxysilane by a soft chemistry method. The nanoimmunosensing architecture was prepared by in situ electropolymerization of 3,4-ethylenedioxythiophene (EDOT) on SPAuE in the presence of CeO₂ NPs. The CeO₂ NPs and Ce/PEDOT/SPAuE were characterized by scanning and transmission electron microscopy, dynamic and electrophoretic light scattering, ultraviolet-visible spectrophotometry, X-ray diffraction, Fourier-transform infrared spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Ce/PEDOT/SPAuE was biofunctionalized with p53 antigen by covalent bonding for the label-free determination of anti-p53 autoantibodies by differential pulse voltammetry. The nanobiocomposite-based nanoimmunosensor detected anti-p53 autoantibodies in a linear range from 10 to 1000 pg mL^-1, with a limit of detection (LOD) of 3.2 pg mL^-1. The nanoimmunosensor offered high specificity, selectivity, and long-term storage stability with great potential to detect anti-p53 autoantibodies in serum samples. Overall, incorporating organo-functional nanoparticles into polymeric matrices can provide a simple-to-assemble, rapid, and ultrasensitive approach for on-site screening of anti-p53 autoantibodies and other disease-related biomarkers with low sample volumes.

HSymM-guided engineering of the immunodominant p53 transactivation domain putative peptide antigen for improved binding to its anti-p53 monoclonal antibody

A novel engineering strategy to improve autoantibody detection with peptide fragments derived from the parent antigen is presented. The model system studied was the binding of the putative p53 TAD peptide antigen (residues 46-55) to its cognate anti-p53 antibody, ab28. Each engineered peptide contained the full decapeptide epitope and differed only in the flanking regions. Since minimal structural information was available to guide the design, a simple epitope:paratope binding model was applied. The Hidden Symmetry Model, which we recently reported, was used to guide peptide design and estimate per-residue contributions to interaction free energy as a function of added C- and N-terminal flanking peptides. Twenty-four peptide constructs were designed, synthesized, and assessed for binding affinity to ab28 by surface plasmon resonance, and a subset of these peptides were evaluated in a simulated immunoassay for limit of detection. Many peptides exhibited over 200-fold enhancements in binding affinity and improved limits of detection. The epitope was reevaluated and is proposed to be the undecapeptide corresponding to residues 45-55. HSymM calculated binding free energy and experimental data were found to be in good agreement (R2 > 0.75).

Prognostic value of circulating Bcl-2 and anti-p53 antibodies in patients with breast cancer: A long term follow-up (17.5 years)

BACKGROUND

Apoptosis inhibition is a major tumorigenic factor. Bcl-2 dysregulation and TP53 mutation status, which may correlate with autoantibody generation, contribute to impaired apoptosis.

OBJECTIVE

This study aimed to investigate the prognostic value of circulating Bcl-2 and anti-p53 antibodies (p53Abs) in a 17.5-year follow-up of breast cancer patients. We also analyzed the correlations of Bcl-2 and p53Abs with various clinicopathological parameters in order to assess their impact on tumor aggressiveness.

METHODS

Serum Bcl-2 and p53Abs levels were analyzed by the enzyme-linked immunosorbent assay (ELISA) in 82 patients with invasive breast cancer and twenty individuals without malignancy.

RESULTS

Serum Bcl-2 and p53Abs levels in breast cancer patients were significantly higher than those in controls. Patients with high levels of Bcl-2 (cut-off 200 U/ml) had a poorer prognosis (17.5-year survival) than those with lower Bcl-2 values. In combined analysis the subgroup of patients with elevated p53Abs (cut-off 15 U/ml) and elevated Bcl-2 (cut-offs 124 U/ml and 200 U/ml) had the worse prognosis in 17.5-year survival. In correlation analysis p53Abs and Bcl-2 were associated with unfavorable clinicopathological parameters.

CONCLUSIONS

Our results suggest that breast cancer patients with high serum levels of p53Abs and Bcl-2 present an especially unfavorable group in a long follow-up.

Immunodiagnostic Biomarkers for Hepatocellular Carcinoma (HCC): The First Step in Detection and Treatment

Hepatocellular carcinoma (HCC) exerts huge effects on the health burden of the world because of its high mortality and poor prognosis. HCC is often clinically detected late in patients. If HCC could be detected and treated earlier, the survival rate of patients will be greatly improved. Therefore, identifying specific biomarkers is urgent and important for HCC. The liver is also recognized as an immune organ. The occurrence of HCC is related to exacerbation of immune tolerance and/or immunosurveillance escape. The host immune system plays an important role in the recognition and targeting of tumor cells in cancer immunotherapy, as can be seen from the clinical success of immune checkpoint inhibitors and chimeric antigen receptor (CAR) T cells. Thus, there is a pressing medical need to discover immunodiagnostic biomarkers specific to HCC for understanding the pathological mechanisms of HCC, especially for immunotherapy targets. We have reviewed the existing literature to summarize the immunodiagnostic markers of HCC, including autoantibodies against tumor-associated antigens (TAAs) and exosomes, to provide new insights into HCC and early detection of this deadly cancer.

The implication of autoantibodies in early diagnosis and monitoring of plasmonic photothermal therapy in the treatment of feline mammary carcinoma

Feline mammary carcinoma (FMC) shows great similarities to human breast cancer in the cellular and molecular levels. So, in cats as in humans, the role of immune responses is indicated to detect and follow up the development of tumors. As a new breast cancer therapeutic approach, Plasmonic Photothermal Therapy (PPTT) is an effective localized treatment for canine and feline mammary-carcinoma. Its systemic effect has not been inquired yet and needs many studies to hypothesis how the PPTT eradicates tumor cells. In this study, it is the first time to detect (P53, PCNA, MUC-1, and C-MYC) feline autoantibodies (AAbs), study the relationship between PCNA AAbs and mammary-tumors, and investigate the effect of PPTT on the humoral immune response of cats with mammary-carcinoma through detection of AAbs level before, during, and after the treatment. The four-AAbs panel was evaluated in serum of normal and clinically diagnosed cats with mammary tumors using Enzyme-Linked Immunosorbent Assay. The panel showed 100% specificity and 93.7% sensitivity to mammary tumors. The panel was evaluated in PPTT monotherapy, mastectomy monotherapy, and combination therapy. PPTT monotherapy decreased AAbs level significantly while mastectomy monotherapy and combination therapy had a nonsignificant effect on AAbs level.

The Glycolytic Pathway as a Target for Novel Onco-Immunology Therapies in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal forms of human cancer, characterized by unrestrained progression, invasiveness and treatment resistance. To date, there are limited curative options, with surgical resection as the only effective strategy, hence the urgent need to discover novel therapies. A platform of onco-immunology targets is represented by molecules that play a role in the reprogrammed cellular metabolism as one hallmark of cancer. Due to the hypoxic tumor microenvironment (TME), PDA cells display an altered glucose metabolism-resulting in its increased uptake-and a higher glycolytic rate, which leads to lactate accumulation and them acting as fuel for cancer cells. The consequent acidification of the TME results in immunosuppression, which impairs the antitumor immunity. This review analyzes the genetic background and the emerging glycolytic enzymes that are involved in tumor progression, development and metastasis, and how this represents feasible therapeutic targets to counteract PDA. In particular, as the overexpressed or mutated glycolytic enzymes stimulate both humoral and cellular immune responses, we will discuss their possible exploitation as immunological targets in anti-PDA therapeutic strategies.

Usefulness of Serum Anti-p53 Antibody Measurement in Patients Undergoing Hepatectomy for Colorectal Liver Metastases

BACKGROUND

While anti-p53 antibody (p53-Ab) is a potential marker for early detection of colorectal cancer, its clinical utility in patients with advanced colorectal cancer remains unknown.

METHODS

The clinical significance of p53-Ab was investigated by analyzing the data of 206 patients who underwent curative resection for colorectal liver metastases.

RESULTS

Of the 206 patients, 60 (29%) were seropositive and 146 were seronegative for p53-Ab before the surgery. The preoperative serum p53-Ab level showed no significant correlation with the serum CEA or serum CA19-9 levels. The perioperative changes in serum p53-Ab positivity were significantly correlated with the preoperative serum p53-Ab levels and multivariate analysis confirmed that a higher preoperative p53-Ab level was independently associated with a worse recurrence-free survival (hazard ratio [HR], 1.07; 95% CI, 1.01-1.13; P = 0.033 per + 100 U/mL), even after adjustments for other oncological factors, including the preoperative serum CEA level.

CONCLUSION

Higher preoperative p53-Ab levels were associated with a higher risk of recurrence after curative resection of colorectal liver metastases.

Anti-Cancer Auto-Antibodies: Roles, Applications and Open Issues

Auto-antibodies are classically associated with autoimmune diseases, where they are an integral part of diagnostic panels. However, recent evidence is accumulating on the presence of auto-antibodies against single or selected panels of auto-antigens in many types of cancer. Auto-antibodies might initially represent an epiphenomenon derived from the inflammatory environment induced by the tumor. However, their effect on tumor evolution can be crucial, as is discussed in this paper. It has been demonstrated that some of these auto-antibodies can be used for early detection and cancer staging, as well as for monitoring of cancer regression during treatment and follow up. Interestingly, certain auto-antibodies were found to promote cancer progression and metastasis, while others contribute to the body's defense against it. Moreover, auto-antibodies are of a polyclonal nature, which means that often several antibodies are involved in the response to a single tumor antigen. Dissection of these antibody specificities is now possible, allowing their identification at the genetic, structural, and epitope levels. In this review, we report the evidence available on the presence of auto-antibodies in the main cancer types and discuss some of the open issues that still need to be addressed by the research community.

New Assay System Elecsys Anti-p53 to Detect Serum Anti-p53 Antibodies in Esophageal Cancer Patients and Colorectal Cancer Patients: Multi-institutional Study

BACKGROUND

Several recent studies suggest that serum anti-p53 antibodies (s-p53-Abs) may be combined with other markers to detect esophageal and colorectal cancer. In this study, we assessed the sensitivity and specificity of s-p53-Abs detection of a new electrochemiluminescence immunoassay (ECLIA; Elecsys anti-p53).

METHODS

Elecsys anti-p53 assay was used to analyze the level of s-p53-Abs in blood sera from patients with esophageal or colorectal cancer taken before treatment. Control blood sera from healthy volunteers, patients with benign diseases, and patients with autoimmune diseases served as a reference. In addition, squamous cell carcinoma antigen (SCC-Ag) and cytokeratin 19 fragments (CYFRA21-1) were assessed in patients with esophageal cancer, and carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 were assessed in patients with colorectal cancer.

RESULTS

Samples from 281 patients with esophageal cancer, 232 patients with colorectal cancer, and 532 controls were included in the study. The median value of s-p53-Abs in control samples was < 0.02 μg/mL (range < 0.02-29.2 μg/mL). Assuming 98% specificity, the cut-off value was determined as 0.05 μg/mL. s-p53-Abs were detected in 20% (57/281) of patients with esophageal cancer and 18% (42/232) of patients with colorectal cancer. In combination with SCC-Ag and CEA, respectively, s-p53-Abs detected 51% (144/281) of patients with esophageal and 53% (124/232) of patients with colorectal cancer.

CONCLUSIONS

The new s-p53-Abs assay Elecsys anti-p53 was useful in detecting esophageal and colorectal cancers with high specificity. Adding s-p53-Abs to conventional markers significantly improved the overall detection rates.

Autoantibody profiling identifies predictive biomarkers of response to anti-PD1 therapy in cancer patients

Background: Programmed cell death protein 1 (PD1) inhibitors have revolutionized cancer therapy, yet many patients fail to respond. Thus, the identification of accurate predictive biomarkers of therapy response will improve the clinical benefit of anti-PD1 therapy.

Method: We assessed the baseline serological autoantibody (AAb) profile against ~2300 proteins in 10 samples and ~4600 proteins in 35 samples with alveolar soft part sarcoma (ASPS), non-small-cell lung cancer (NSCLC) and lymphoma using Nucleic Acid Programmable Protein Arrays (NAPPA). 23 selected potential AAb biomarkers were verified using simple, affordable and rapid enzyme linked immune sorbent assay (ELISA) technology with baseline plasma samples from 12 ASPS, 16 NSCLC and 46 lymphoma patients. SIX2 and EIF4E2 AAbs were further validated in independent cohorts of 17 NSCLC and 43 lymphoma patients, respectively, using ELISA. The IgG subtypes in response to therapy were also investigated.

Results: Distinct AAb profiles between ASPS, NSCLC and lymphoma were observed. In ASPS, the production of P53 and PD1 AAbs were significantly increased in non-responders (p=0.037). In NSCLC, the SIX2 AAb was predictive of response with area under the curve (AUC) of 0.87, 0.85 and 0.90 at 3 months, 4.5 months, 6 months evaluation time points, respectively. In the validation cohort, the SIX2 AAb was consistently up-regulated in non-responders (p=0.024). For lymphoma, the EIF4E2 AAb correlated with a favorable response with AUCs of 0.68, 0.70, and 0.70 at 3 months, 4.5 months, and 6 months, respectively. In the validation cohort, the AUCs were 0.74, 0.75 and 0.66 at 3 months, 4.5 months, and 6 months, respectively. The PD1 and PD-L1 IgG2 AAbs were highly produced in ~20% of lymphoma responders. Furthermore, bioinformatics analysis revealed antigen functions of these AAb biomarkers.

Conclusion: This study provides the first evidence that AAb biomarkers selected using high-throughput protein microarrays can predict anti-PD1 therapeutic response and guide anti-PD1 therapy.

P53: A Guardian of Immunity Becomes Its Saboteur through Mutation

Awareness of the importance of immunity in controlling cancer development triggered research into the impact of its key oncogenic drivers on the immune response, as well as their value as targets for immunotherapy. At the heart of tumour suppression is p53, which was discovered in the context of viral infection and now emerges as a significant player in normal and cancer immunity. Wild-type p53 (wt p53) plays fundamental roles in cancer immunity and inflammation. Mutations in p53 not only cripple wt p53 immune functions but also sinisterly subvert the immune function through its neomorphic gain-of-functions (GOFs). The prevalence of mutant p53 across different types of human cancers, which are associated with inflammatory and immune dysfunction, further implicates mutant p53 in modulating cancer immunity, thereby promoting tumorigenesis, metastasis and invasion. In this review, we discuss several mutant p53 immune GOFs in the context of the established roles of wt p53 in regulating and responding to tumour-associated inflammation, and regulating innate and adaptive immunity. We discuss the capacity of mutant p53 to alter the tumour milieu to support immune dysfunction, modulate toll-like receptor (TLR) signalling pathways to disrupt innate immunity and subvert cell-mediated immunity in favour of immune privilege and survival. Furthermore, we expose the potential and challenges associated with mutant p53 as a cancer immunotherapy target and underscore existing therapies that may benefit from inquiry into cancer p53 status.

Prognostic impact of p53 and/or NY-ESO-1 autoantibody induction in patients with gastroenterological cancers

BACKGROUND AND AIM

We evaluated the clinicopathological and prognostic significance of serum p53 (s-p53-Abs) and serum NY-ESO-1 autoantibodies (s-NY-ESO-1-Abs) in esophageal squamous cell carcinoma (ESCC), gastric cancer and hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

A total of 377 patients, 85 patients with ESCC, 248 patients with gastric cancer, and 44 patients with HCC were enrolled to measure s-p53-Abs and s-NY-ESO-1-Abs titers by the enzyme-linked immunosorbent assay before treatment. The clinicopathological significance and prognostic impact of the presence of autoantibodies were evaluated. Expression data based on the Cancer Genome Atlas and the prognostic impact of gene expression was also examined for discussion.

RESULTS

The positive rates of s-p53-Abs were 32.9% in ESCC, 15% in gastric cancer, and 4.5% in HCC. The positive rates of s-NY-ESO-1-Abs were 29.4% in ESCC, 9.7% in gastric cancer, and 13.6% in HCC. The presence of s-p53-Abs was not associated with tumor progression in these three cancer types. On the other hand, the presence of s-NY-ESO-1-Abs was significantly associated with tumor progression in ESCC and gastric cancer. The presence of s-p53-Abs and/or s-NY-ESO-1-Abs was significantly associated with poor prognosis in gastric cancer but not in ESCC nor HCC.

CONCLUSIONS

The presence of s-p53-Abs and/or s-NY-ESO-1-Abs was associated with tumor progression in ESCC and gastric cancer. These autoantibodies might have poor prognostic impacts on gastric cancer (UMIN000014530).

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.

Sera Anti-P53 Antibody Provides New Information Which Explains the Link Between Diabetes and Cancer

INTRODUCTION

Abnormalities in glucose metabolism in diabetic patients may lead to an increased risk of certain cancers. Epidemiological studies and meta-analysis have shown that factors such as gender, age, obesity, and insulin resistance are related to cancer incidence. The anti-p53 antibody is a known cancer marker due to tumor-associated p53 accumulation. Many studies have aimed to unravel the link between diabetes and cancer. Here, we aimed to elucidate the impact of diabetes on malignancies by analyzing anti-p53 antibody in sera of type 2 diabetes mellitus (T2DM) patients.

MATERIALS AND METHODS

We conducted an observational study with a cross-sectional design. A total of 149 subjects comprised of 78 T2DM patients (32 with cancer risk and 46 subjects without cancer risk), 51 T2DM patients with cancer, and 20 healthy subjects as controls from multisites. The anti-p53 antibody was measured by enzyme-linked immunosorbent assay, while HbA1c was measured using the NGSP standardized method.

RESULTS

We observed an 8.3-fold (p<0.05) increase of anti-p53 antibody in the sera of T2DM patients and a 24-fold increase (p<0.001) in T2DM patients with cancer compared to healthy subjects. The anti-p53 antibodies significantly increased almost three times (p<0.05) in T2DM patients with cancer (0.72 U/mL±0.20) compared to T2DM patients (0.25 U/mL±0.05). Meanwhile, this antibody was almost undetectable in healthy subjects as a control group (0.03 U/mL±0.03). The anti-p53 antibody level was higher in T2DM with cancer risk patients. However, we did not find a significant difference for it in T2DM without cancer risk patients (0.19 U/mL±0.03) and T2DM with cancer risk patients (0.29 U/mL±0.08). Multivariate regression analysis showed that T2DM with cancer was the only one independent factor (beta=0.218, p=0.019) that could predict the increase of anti-p53 antibody, controlled by age, gender, BMI, DM duration, and HbA1c.

CONCLUSION

Our results showed that anti-p53 antibody almost not detected in healthy subjects, but 8.3-fold increase in the sera of T2DM patients and 24-fold increase in T2DM patients with cancer. Therefore, this biomarker provides new information which explains the link between diabetes and cancer.

The specific seroreactivity to ∆Np73 isoforms shows higher diagnostic ability in colorectal cancer patients than the canonical p73 protein

The p53-family is tightly regulated at transcriptional level. Due to alternative splicing, up to 40 different theoretical proteoforms have been described for p73 and at least 20 and 10 for p53 and p63, respectively. However, only the canonical proteins have been evaluated as autoantibody targets in cancer patients for diagnosis. In this study, we have cloned and expressed in vitro the most upregulated proteoforms of p73, ΔNp73α and ΔNp73β, for the analysis of their seroreactivity by a developed luminescence based immunoassay test using 145 individual plasma from colorectal cancer, premalignant individuals and healthy controls. ∆Np73α seroreactivity showed the highest diagnostic ability to discriminate between groups. The combination of ∆Np73α, ∆Np73β and p73 proteoforms seroreactivity were able to improve their individual diagnostic ability. Competitive inhibition experiments further demonstrated the presence of unique specific epitopes in ΔNp73 isoforms not present in p73, with several colorectal patients showing unique and specific seroreactivity to the ΔNp73 proteoforms. Overall, we have increased the complexity of the humoral immune response to the p53-family in cancer patients, showing that the proteoforms derived from the alternative splicing of p73 possess a higher diagnostic ability than the canonical protein, which might be extensive for p53 and p63 proteins.

Antibody Responses to Streptococcus Gallolyticus Subspecies Gallolyticus Proteins in a Large Prospective Colorectal Cancer Cohort Consortium

Background: Antibody responses to Streptococcus gallolyticus subspecies gallolyticus (SGG) proteins, especially pilus protein Gallo2178, have been consistently associated with colorectal cancer risk. Previous case-control studies and prospective studies with up to 8 years of follow-up, however, were unable to decipher the temporality of antibody responses to SGG in the context of the long-term multistep development of colorectal cancer. In this study, we analyzed a large U.S. colorectal cancer cohort consortium with follow-up beyond 10 years for antibody responses to SGG.Methods: We applied multiplex serology to measure antibody responses to 9 SGG proteins in participants of 10 prospective U.S. cohorts (CLUE, CPSII, HPFS, MEC, NHS, NYUWHS, PHS, PLCO, SCCS, and WHI) including 4,063 incident colorectal cancer cases and 4,063 matched controls. Conditional logistic regression was used to assess whether antibody responses to SGG were associated with colorectal cancer risk, overall and by time between blood draw and diagnosis.Results: Colorectal cancer risk was increased among those with antibody responses to Gallo2178, albeit not statistically significant [OR, 1.23; 95% confidence interval (CI), 0.99-1.52]. This association was stronger for cases diagnosed <10 years after blood draw (OR, 1.40; 95% CI, 1.09-1.79), but was not found among cases diagnosed ≥10 years after blood draw (OR, 0.79; 95% CI, 0.50-1.24).Conclusions: In a large cohort consortium, we reproduced the association of antibody responses to SGG Gallo2178 with colorectal cancer risk for individuals diagnosed within 10 years after blood draw.Impact: This timing-specific finding suggests that antibody responses to SGG are associated with increased colorectal cancer risk only after tumorigenesis has begun. Cancer Epidemiol Biomarkers Prev; 27(10); 1186-94. ©2018 AACR.

Potential diagnostic value of serum p53 antibody for detecting colorectal cancer: A meta-analysis

Numerous studies have assessed the diagnostic value of serum p53 (s-p53) antibody in patients with colorectal cancer (CRC); however, results remain controversial. The present study aimed to comprehensively and quantitatively summarize the potential diagnostic value of s-p53 antibody in CRC. The present study utilized databases, including PubMed and EmBase, systematically regarding s-p53 antibody diagnosis in CRC, accessed on and prior to 31 July 2016. The quality of all the included studies was assessed using quality assessment of studies of diagnostic accuracy (QUADAS). The result of pooled sensitivity, pooled specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were analyzed and compared with overall accuracy measures using diagnostic odds ratios (DORs) and area under the curve (AUC) analysis. Publication bias and heterogeneity were also assessed. A total of 11 trials that enrolled a combined 3,392 participants were included in the meta-analysis. Approximately 72.73% (8/11) of the included studies were of high quality (QUADAS score >7), and all were retrospective case-control studies. The pooled sensitivity was 0.19 [95% confidence interval (CI), 0.18–0.21] and pooled specificity was 0.93 (95% CI, 0.92–0.94). Results also demonstrated a PLR of 4.56 (95% CI, 3.27–6.34), NLR of 0.78 (95% CI, 0.71–0.85) and DOR of 6.70 (95% CI, 4.59–9.76). The symmetrical summary receiver operating characteristic curve was 0.73. Furthermore, no evidence of publication bias or heterogeneity was observed in the meta-analysis. Meta-analysis data indicated that s-p53 antibody possesses potential diagnostic value for CRC. However, discrimination power was somewhat limited due to the low sensitivity.

Prediagnostic Antibodies to Serum p53 and Subsequent Colorectal Cancer

Background: The presence of circulating antibodies to the p53 tumor suppressor protein is a potential early detection colorectal cancer biomarker. However, studies of prediagnostic measures of p53 seropositivity in relation to colorectal cancer risk are limited.Methods: We conducted a nested case-control study of serum p53 autoantibodies and risk of colorectal cancer within the Cancer Prevention Study-II Nutrition Cohort. Among cohort participants who were cancer free at the time of blood collection, 392 were subsequently diagnosed with colorectal cancer over 11 years of follow-up. Two controls were matched to each case on birth date, blood draw date, race, and sex. Autoantibodies to p53 were detected in 41 of the 392 cases (10.5%) and 49 of the 774 controls (6.3%).Results: Participants who were seropositive for p53 antibodies before diagnosis were more likely to be subsequently diagnosed with colorectal cancer [RR = 1.77; 95% confidence interval (CI), 1.12-2.78]. This association was strongest within 3 years of diagnosis (RR = 2.26; 95% CI, 1.06-4.83). An association was also suggested when colorectal cancer was diagnosed 4 to <6 years after p53 measurement (RR = 1.84; 95% CI, 0.89-3.79), but not 6 or more years later (RR = 1.15; 95% CI, 0.44-2.99).Conclusions: If these results are confirmed, serum p53 antibodies may be useful on a panel of early detection markers for colorectal cancer.Impact: Individuals who were seropositive for p53 antibodies were twice as likely to develop colorectal cancer within the next 3 years compared with those who were seronegative. This marker is a good candidate for inclusion on an early detection marker panel for colorectal cancer. Cancer Epidemiol Biomarkers Prev; 27(2); 219-23. ©2017 AACR.

Novel potential serological prostate cancer biomarkers using CT100+ cancer antigen microarray platform in a multi-cultural South African cohort

There is a growing need for high throughput diagnostic tools for early diagnosis and treatment monitoring of prostate cancer (PCa) in Africa. The role of cancer-testis antigens (CTAs) in PCa in men of African descent is poorly researched. Hence, we aimed to elucidate the role of 123 Tumour Associated Antigens (TAAs) using antigen microarray platform in blood samples (N = 67) from a South African PCa, Benign prostatic hyperplasia (BPH) and disease control (DC) cohort. Linear (fold-over-cutoff) and differential expression quantitation of autoantibody signal intensities were performed. Molecular signatures of candidate PCa antigen biomarkers were identified and analyzed for ethnic group variation. Potential cancer diagnostic and immunotherapeutic inferences were drawn. We identified a total of 41 potential diagnostic/therapeutic antigen biomarkers for PCa. By linear quantitation, four antigens, GAGE1, ROPN1, SPANXA1 and PRKCZ were found to have higher autoantibody titres in PCa serum as compared with BPH where MAGEB1 and PRKCZ were highly expressed. Also, p53 S15A and p53 S46A were found highly expressed in the disease control group. Statistical analysis by differential expression revealed twenty-four antigens as upregulated in PCa samples, while 11 were downregulated in comparison to BPH and DC (FDR = 0.01). FGFR2, COL6A1and CALM1 were verifiable biomarkers of PCa analysis using urinary shotgun proteomics. Functional pathway annotation of identified biomarkers revealed similar enrichment both at genomic and proteomic level and ethnic variations were observed. Cancer antigen arrays are emerging useful in potential diagnostic and immunotherapeutic antigen biomarker discovery.

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.

Serum autoantibodies against a panel of 15 tumor-associated antigens in the detection of ovarian cancer

In this study, enzyme-linked immunosorbent assay has been used to examine the frequencies of serum autoantibodies against two candidate tumor-associated antigens intensively selected from the Human Protein Atlas database, in combination with 13 tumor-associated antigens available from our lab in sera from 44 OC patients and 50 normal healthy controls. Conventional evaluation (mean + 3SD as the cutoff value to determine a positive reactivity), receiver operating characteristic curve analyses, and classification tree analysis were further used to evaluate the diagnostic performance of autoantibodies against these tumor-associated antigens (anti-tumor-associated antigens) in ovarian cancer. For single anti-tumor-associated antigen, when the cutoff values were set as mean + 3SD of normal healthy controls, NPM1, MDM2, PLAT, p53, and c-Myc could achieve sensitivity higher than 20% at 98% specificity. Combinational utilization of autoantibodies against MDM2, PLAT, NPM1, 14-3-3 Zeta, p53, and RalA achieved the optimal diagnostic performance with 72.7% sensitivity at 96% specificity. Receiver operating characteristic curve analysis showed that the area under the receiver operating characteristic curves of autoantibodies against c-Myc, NPM1, MDM2, p16, p53, and 14-3-3 Zeta were greater than 0.80. This indicated that these tumor-associated antigens held high potential to serve as diagnostic biomarkers in ovarian cancer detection. Decision tree analysis indicated that anti-c-Myc held high potential in the detection of ovarian cancer. Further studies are warranted to validate the diagnostic performance of these anti-tumor-associated antigens with high area under the receiver operating characteristic curve, including autoantibodies against c-Myc, MDM2, PLAT, NPM1, 14-3-3 Zeta, p53, and RalA.

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.

Prognostic Value of Pre- and Postoperative Anti-p53 Antibody Levels in Colorectal Cancer Patients: A Retrospective Study

OBJECTIVE

To determine the utility of the post-/preoperative anti-p53 antibody (p53 Ab) ratio as a prognostic factor for colorectal cancer (CRC) recurrence.

METHODS

A total of 737 nonmetastatic CRC patients who had undergone R0 resection were retrospectively analyzed. p53 Ab levels were measured within 1 month prior to and at least every 3 months after surgery. Post-/preoperative p53 Ab ratios were calculated, and the optimal ratio cutoff values for predicting recurrence were determined using the Kaplan-Meier method and the log-rank test.

RESULTS

Preoperative p53 Ab elevation was observed in 194 patients (pre-p53 high). Preoperative p53 Ab levels correlated with TNM stage. Re-elevation of p53 Ab levels occurred on recurrence in the pre-p53 high group, but not in the pre-p53 low group (n = 543). In the pre-p53 high group, patients who experienced tumor recurrence exhibited a slow postoperative reduction of p53 Ab levels, and a post-/preoperative p53 Ab ratio >0.4 at postoperative 3 months predicted relapse-free survival. In other words, a p53 Ab level remaining higher than 40% of the preoperative level was an independent and strong risk factor for recurrence in multivariate analyses.

CONCLUSION

In CRC patients with preoperative p53 Ab elevation, the rate of p53 Ab reduction in the early postsurgical period is a promising prognostic factor for recurrence.

Immunoseroproteomic Profiling in African American Men with Prostate Cancer: Evidence for an Autoantibody Response to Glycolysis and Plasminogen-Associated Proteins

African American (AA) men suffer from a disproportionately high incidence and mortality of prostate cancer (PCa) compared with other racial/ethnic groups. Despite these disparities, African American men are underrepresented in clinical trials and in studies on PCa biology and biomarker discovery. We used immunoseroproteomics to profile antitumor autoantibody responses in AA and European American (EA) men with PCa, and explored differences in these responses. This minimally invasive approach detects autoantibodies to tumor-associated antigens that could serve as clinical biomarkers and immunotherapeutic agents. Sera from AA and EA men with PCa were probed by immunoblotting against PC3 cell proteins, with AA sera showing stronger immunoreactivity. Mass spectrometry analysis of immunoreactive protein spots revealed that several AA sera contained autoantibodies to a number of proteins associated with both the glycolysis and plasminogen pathways, particularly to alpha-enolase (ENO1). The proteomic data is deposited in ProteomeXchange with identifier PXD003968. Analysis of sera from 340 racially diverse men by enzyme-linked immunosorbent assays (ELISA) showed higher frequency of anti-ENO1 autoantibodies in PCa sera compared with control sera. We observed differences between AA-PCa and EA-PCa patients in their immunoreactivity against ENO1. Although EA-PCa sera reacted with higher frequency against purified ENO1 in ELISA and recognized by immunoblotting the endogenous cellular ENO1 across a panel of prostate cell lines, AA-PCa sera reacted weakly against this protein by ELISA but recognized it by immunoblotting preferentially in metastatic cell lines. These race-related differences in immunoreactivity to ENO1 could not be accounted by differential autoantibody recognition of phosphoepitopes within this antigen. Proteomic analysis revealed differences in the posttranslational modification profiles of ENO1 variants differentially recognized by AA-PCa and EA-PCa sera. These intriguing results suggest the possibility of race-related differences in the antitumor autoantibody response in PCa, and have implications for defining novel biological determinants of PCa health disparities.

Paradoxical Reductions in Serum Anti-p53 Autoantibody Levels by Chemotherapy in Unresectable Colorectal Cancer: An Observational Study

OBJECTIVE

The anti-p53 autoantibody is an emerging tumor marker that is commonly produced in response to p53 mutations. The usefulness of this antibody has been suggested in screening for and the monitoring of recurrence in colorectal cancer; however, its significance as a marker during chemotherapy remains largely unknown.

METHODS

We measured serum anti-p53 antibody levels in patients with unresectable colorectal cancer who underwent first-line systemic chemotherapy. Tumor responses were evaluated by computed tomography. We determined whether temporal changes in this antibody during therapy are associated with radiological responses.

RESULTS

Of the 83 patients in our study, 29 (35%) had elevated serum anti-p53 antibody levels before chemotherapy. Among these, antibody levels decreased in all 14 responders. In contrast, among those patients with elevated pretherapeutic serum anti-p53 antibody levels, 89% showed a paradoxical decrease in antibody levels and exhibited disease progression after chemotherapy. Moreover, serum anti-p53 antibody levels before and after chemotherapy were not associated with survival.

CONCLUSION

These results suggest that serum anti-p53 antibody levels are of limited value in the evaluation of responses to palliative chemotherapy in patients with colorectal cancer.

Proteomic mapping of p53 immunogenicity in pancreatic, ovarian, and breast cancers

PURPOSE

Mutations in TP53 induce autoantibody immune responses in a subset of cancer patients, which have been proposed as biomarkers for early detection. Here, we investigate the association of p53-specific autoantibodies with multiple tumor subtypes and determine the association with p53 mutation status and epitope specificity.

EXPERIMENTAL DESIGN

IgG p53 autoantibodies (p53-AAb), were quantified in 412 serum samples using a programmable ELISA assay from patients with serous ovarian, pancreatic adenocarcinoma, and breast cancer. To determine if patients generated mutation-specific autoantibodies we designed a panel of the most relevant 51 p53 point mutant proteins, to be displayed on custom programmable protein microarrays. To determine the epitope specificity we displayed 12 overlapping tiling fragments and 38 N- and C-terminal deletions spanning the length of the wild-type p53 protein.

RESULTS

We detected p53-AAb with sensitivities of 58.8% (ovarian), 22% (pancreatic), 32% (triple negative breast cancer), and 10.2% (HER2+ breast cancer) at 94% specificity. Sera with p53-AAb contained broadly reactive autoantibodies to 51 displayed p53 mutant proteins, demonstrating a polyclonal response to common epitopes. All p53-AAb displayed broad polyclonal immune response to both continuous and discontinuous epitopes at the N- and C-terminus as well as the DNA-binding domain.

CONCLUSION AND CLINICAL RELEVANCE

In this comprehensive analysis, mutations in tumor p53 induce strong, polyclonal autoantibodies with broadly reactive epitope specificity.

Expression of MCRS1 and MCRS2 and their correlation with serum carcinoembryonic antigen in colorectal cancer

Cancer-associated genes serve a crucial role in carcinogenesis. The present study aimed to investigate the mRNA expression levels of microspherule protein 1 (MCRS1) and MCRS2 in colorectal cancer (CRC) and their association with clinical variables. The mRNA expression levels of MCRS1 and MCRS2 were assessed by semi-quantitative reverse transcription polymerase chain reaction in the tumor and corresponding non-tumor tissues of 54 newly-diagnosed CRC patients, as well as in the normal colonic mucosa tissue of 19 age/gender-matched healthy controls. Immunofluorescence was also employed to identify the expression of MCRS1 in CRC tissues, while the concentration of serum carcinoembryonic antigen (CEA) was determined by an enzyme-linked immunoassay. The results identified a negative correlation between MCRS1 and MCRS2 expression levels (r=-0.3018, P=0.0266). MCRS1 mRNA expression was significantly increased and MCRS2 mRNA expression was decreased in CRC tissues compared with the levels in the corresponding normal tissues (both P<0.001). An increase in MCRS1 expression and a decrease in MCRS2 expression was detected in advanced stage when compared with early stage CRC patients. Immunofluorescence analysis revealed increased expression of MCRS1 in CRC patients. Furthermore, the expression levels of MCRS1 displayed positive correlation, whilst those of MCRS2 displayed negative correlation, with the serum CEA level in patients with CRC. The results suggest that increased MCRS1 and decreased MCRS2 expression appeared to be involved in the pathogenesis of CRC. The present study provides evidence suggesting that MCRS1 and MCRS2 may identify CRC patients at a risk of disease relapse, and thus, may be potential tools for monitoring disease activity and act as novel diagnostic markers in the treatment of CRC.

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.

Evaluation of a 5-Marker Blood Test for Colorectal Cancer Early Detection in a Colorectal Cancer Screening Setting

PURPOSE

In initial studies that included colorectal cancer patients undergoing diagnostic colonoscopy, we had identified a serum marker combination able to detect colorectal cancer with similar diagnostic performance as fecal immunochemical test (FIT). In this study, we aimed to validate the results in participants of a large colorectal cancer screening study conducted in the average-risk, asymptomatic screening population.

EXPERIMENTAL DESIGN

We tested serum samples from 1,200 controls, 420 advanced adenoma patients, 4 carcinoma in situ patients, and 36 colorectal cancer patients with a 5-marker blood test [carcinoembryonic antigen (CEA)+anti-p53+osteopontin+seprase+ferritin]. The diagnostic performance of individual markers and marker combinations was assessed and compared with stool test results.

RESULTS

AUCs for the detection of colorectal cancer and advanced adenomas with the 5-marker blood test were 0.78 [95% confidence interval (CI), 0.68-0.87] and 0.56 (95% CI, 0.53-0.59), respectively, which now is comparable with guaiac-based fecal occult blood test (gFOBT) but inferior to FIT. With cutoffs yielding specificities of 80%, 90%, and 95%, the sensitivities for the detection of colorectal cancer were 64%, 50%, and 42%, and early-stage cancers were detected as well as late-stage cancers. For osteopontin, seprase, and ferritin, the diagnostic performance in the screening setting was reduced compared with previous studies in diagnostic settings while CEA and anti-p53 showed similar diagnostic performance in both settings.

CONCLUSIONS

Performance of the 5-marker blood test under screening conditions is inferior to FIT even though it is still comparable with the performance of gFOBT. CEA and anti-p53 could contribute to the development of a multiple marker blood-based test for early detection of colorectal cancer.

Does anti-p53 antibody status predict for clinical outcomes in metastatic colorectal cancer patients treated with fluoropyrimidine, oxaliplatin, plus bevacizumab as first-line chemotherapy?

BACKGROUND

TP53 gene mutation is widely known as one of the determinants of impaired chemosensitivity. p53 is a tumor-suppressor protein in humans encoded by the TP53 gene. Some studies have shown that TP53 gene mutation and accumulation of the p53 protein are closely related with serum anti-p53 antibody positivity. This study aimed to evaluate the predictive significance of the serum p53 antibody status in metastatic colorectal cancer (mCRC) patients treated with fluoropyrimidine, oxaliplatin, plus bevacizumab as first-line chemotherapy.

METHODS

Ninety patients treated with fluoropyrimidine, oxaliplatin plus bevacizumab as first-line chemotherapy were enrolled, including 70 whose KRAS genotype was revealed at the beginning of treatment. Before chemotherapy initiation, the serum p53 antibody level was quantified by enzyme-linked immunosorbent assay using MESACUP® anti-p53 test kits. The cutoff value for positivity was 1.3 U/mL, as calculated previously. The KRAS genotype of the tumor samples was analyzed using the Luminex® assay.

RESULTS

Overall response rates of Response Evaluation Criteria in Solid Tumors criteria were 77.7 % (42/54) in anti-p53-negative patients and 69.4 % (25/36) in anti-p53-positive patients. The odds ratio was 1.07. Median overall survival was 36.1 months in the anti-p53-positive patients, and not available in the anti-p53-negative patients (hazard ratio, 0.81; 95 % confidence interval, 0.37-1.77; P = 0.61). The corresponding values for median progression-free survival were 13.3 months and 14.6 months (hazard ratio, 0.69; 95 % confidence interval, 0.41-1.17; P = 0.17), respectively.

CONCLUSIONS

Serum anti-p53 antibody positivity did not predict chemoresistance in mCRC treated with fluoropyrimidine, oxaliplatin, plus bevacizumab as first-line chemotherapy.

Prognostic Role of Serum Antibody Immunity to p53 Oncogenic Protein in Ovarian Cancer: A Systematic Review and a Meta-Analysis

Objective

Serum p53 autoantibodies (p53-AAbs) are the product of an endogenous immune response against p53 overexpression driven by the ovarian tumour. The p53-AAbs are detectable only in a subset of patients. To date, the evidence of an association between the presence of p53-AAbs and ovarian cancer outcomes has been poorly investigated.

Methods

A systematic literature search was performed to identify eligible studies investigating the association of serum p53-AAbs and overall survival (OS) and disease free survival (DFS). Associations between presence of serum p53-AAbs and baseline tumour characteristics were also evaluated. Pooled hazard ratios (HRs) and corresponding 95% confidence intervals (CI) were computed to estimate the prognostic impact of serum p53-AAbs. Heterogeneity between studies was assessed.

Results

A total of 583 patients (7 studies) for OS and 356 patients (4 studies) for DFS were included in the meta-analysis. Presence of p53-AAbs was not associated to OS (pooled uni- multivariate HR = 1.09; 95% CI: 0.55–2.16), and a large heterogeneity was found. When only multivariate HRs were pooled together (4 studies), presence of p53-AAbs was significantly associated to a better OS (pooled HR = 0.57; 95% CI: 0.40–0.81), and no significant heterogeneity was observed. A reduced DFS was associated to p53-AAbs (pooled uni- multivariate HR = 1.37; 95% CI: 0.83–2.25), though not significantly and with a moderate heterogeneity.

Conclusions

The prognostic significance of serum p53-AAbs in ovarian cancer was diverging according to uni or multivariate models used. Since the results of this work were based on only few investigations, large prospective studies are needed to better define the role of antibody immunity against p53.

Autoantibodies against tumor-associated antigens for detection of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common tumors worldwide. The survival rate after the onset of symptoms is generally less than one year for the late presentation of HCC, and reliable tools for early diagnosis are lacking. Therefore, novel biomarkers for the early detection of HCC are urgently required. Recent studies show that the abnormal release of proteins by tumor cells can elicit humoral immune responses to self-antigens called tumor-associated antigens (TAAs). The corresponding autoantibodies can be detected before the clinical diagnosis of cancer. Therefore, there is growing interest in using serum autoantibodies as cancer biomarkers. In this review, we focus on the advances in research on autoantibodies against TAAs as serum biomarker for detection of HCC, the mechanism of the production of TAAs, and the association of autoantibodies with patients’ clinical characteristics.

Colorectal carcinogenesis-update and perspectives

Colorectal cancer (CRC) is a very common malignancy in the Western World and despite advances in surgery, chemotherapy and screening, it is still the second leading cause of cancer deaths in this part of the world. Numerous factors are found important in the development of CRC including colonocyte metbolism, high risk luminal environment, inflammation, as well as lifestyle factors such as diet, tobacco, and alchohol consumption. In recent years focus has turned towards the genetics and molecular biology of CRC and several interesting and promising correlations and pathways have been discovered. The major genetic pathways of CRC are the Chromosome Instability Pathway representing the pathway of sporadic CRC through the K-ras, APC, and P53 mutations, and the Microsatellite Instability Pathway representing the pathway of hereditary non-polyposis colon cancer through mutations in mismatch repair genes. To identify early cancers, screening programs have been initiated, and the leading strategy has been the use of faecal occult blood testing followed by colonoscopy in positive cases. Regarding the treatment of colorectal cancer, significant advances have been made in the recent decade. The molecular targets of CRC include at least two important cell surface receptors: the epidermal growth factor receptor and the vascular endothelial growth factor receptor. The genetic and molecular knowledge of CRC has widen the scientific and clinical perspectives of diagnosing and treatment. However, despite significant advances in the understanding and treatment of CRC, results from targeted therapy are still not convincing. Future studies will determine the role for this new treatment modality.

A clinical perspective on the role of chronic inflammation in gastrointestinal cancer

Chronic inflammation has been identified as an important risk factor for the development of malignancy, and knowledge about its molecular and cellular mechanisms is increasing. Several chronic inflammatory diseases of the gastrointestinal tract are important as risk factors for malignancy and have been studied in detail. In this review, we summarize important molecular mechanisms in chronic inflammation and highlight established and potential links between chronic inflammation and gastrointestinal cancer. In addition, we present the role of chronic inflammation in numerous tumors within the gastrointestinal tract as well as the relevant pathways or epidemiologic observations linking the pathogenesis of these tumors to inflammation.

Manipulation of tumour-infiltrating B cells and tertiary lymphoid structures: a novel anti-cancer treatment avenue?

Combining different standard therapies with immunotherapy for the treatment of solid tumours has proven to yield a greater clinical benefit than when each is applied separately; however, the percentage of complete responses is still far from optimal, and there is an urgent need for improved treatment modalities. The latest literature data suggest that tertiary lymphoid structures (TLS), previously shown to correlate with the severity of autoimmune diseases or transplant rejection, are also formed in tumours, have a significant beneficial effect on survival and might reflect the generation of an effective immune response in close proximity to the tumour. Thus, the facilitation of TLS formation in tumour stroma could provide novel means to improve the efficiency of immunotherapy and other standard therapies. However, little is known about the mechanisms regulating the formation of tumour-associated TLS. Studies of chronic inflammatory diseases and transplant rejection have demonstrated that TLS formation and/or function requires the presence of B cells. Additionally, the infiltration of B cells into the tumour stroma has been demonstrated to be a significant prognostic factor for improved survival in different human tumours. This suggests that B cells could play a beneficial role in anti-tumour immune response not only in the context of antibody production, antigen presentation and Th1-promoting cytokine production, but also TLS formation. This review focuses on the latest discoveries in tumour-infiltrating B cell functions, their role in TLS formation and relevance in human tumour control, revealing novel opportunities to improve cancer therapies.