Autoantibodies to tumor-associated antigens in epithelial ovarian carcinoma

Expression of cancer-testis antigens in esophageal cancer and their progress in immunotherapy

PURPOSE

Esophageal cancer is a common disease in China with low survival rate due to no obvious early symptoms and lack of effective screening strategies. Traditional treatments usually do not produce desirable results in patients with advanced esophageal cancer, so immunotherapy which relies on tumor-related antigens is needed to combat low survival rates effectively. Cancer-testis antigens (CTA), a large family of tumor-related antigens, have a strong in vivo immunogenicity and tumor-restricted expressing patterns in normal adult tissues. These two characteristics are ideal features of anticancer immunotherapy targets and, therefore, promoted the development of some studies of CTA-based therapy. To provide ideas for the role of the cancer-testis antigens MAGE-A, NY-ESO-1, LAGE-1, and TTK in esophageal cancer, we summarized their expression, prognostic value, and development in immunotherapy.

METHODS

The relevant literature from PubMed is reviewed in this study.

RESULTS

In esophageal cancer, although the relationship between expression of MAGE-A, NY-ESO-1, LAGE-1, and TTK and prognosis value is still in a controversial situation, MAGE-A, NY-ESO-1, LAGE-1, and TTK are highly expressed and can induce specific CTL cells to produce particular killing effect on tumor cells, and some clinical trials have demonstrated that immunotherapy for esophageal cancer patients is effective and safe, which provides a new therapeutic strategy for the treatment of esophageal cancer in the future.

CONCLUSION

In this review, we summarize expression and prognostic value of MAGE-A, NY-ESO-1, LAGE-1, and TTK in esophageal cancer and point out recent advances in immunotherapy about them.

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

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

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.

Mining the human autoantibody repertoire: isolation of potent IL17A-neutralizing monoclonal antibodies from a patient with thymoma

Anti-cytokine autoantibodies have been widely reported to be present in human plasma, both in healthy subjects and in patients with underlying autoimmune conditions, such as autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) or thymic epithelial neoplasms. While often asymptomatic, they can cause or facilitate a wide range of diseases including opportunistic infections. The potential therapeutic value of specific neutralizing anti-cytokine autoantibodies has not been thoroughly investigated. Here we used mammalian cell display to isolate IL17A-specific antibodies from a thymoma patient with proven high-titer autoantibodies against the same. We identified 3 distinct clonotypes that efficiently neutralized IL17A in a cell-based in vitro assay. Their potencies were comparable to those of known neutralizing antibodies, including 2, AIN457 (secukinumab) and ixekizumab that are currently in clinical development for the treatment of various inflammatory disorders. These data clearly demonstrate that the human autoantibody repertoire can be mined for antibodies with high therapeutic potential for clinical development.

Plasma immune analytes in patients with epithelial ovarian cancer

OBJECTIVES

Inflammation is a common feature of epithelial ovarian cancer (EOC), and measurement of plasma markers of inflammation might identify candidate markers for use in screening or presurgical evaluation of patients with adnexal masses.

METHODS

Plasma specimens from cohorts of 100 patients with advanced EOC (AJCC Stage III and IV), 50 patients with early stage EOC (Stage I and II), and 50 patients with benign surgical conditions were assayed for concentrations of multiple cytokines, toll-like receptor agonists, and vascular growth factors via ELISA and electrochemiluminescence. Immune proteins were then analyzed for association with EOC. Differences in plasma protein levels between benign, early, and advanced EOC patient groups were assessed with and without adjustment for plasma cancer antigen 125 (CA-125) levels.

RESULTS

Out of 23 proteins tested, six-including interferon gamma (IFNγ), interleukin 6 (IL-6), IL-8, IL-10, tumor necrosis factor alpha (TNFα), and placental growth factor (PlGF)-were univariately associated with EOC (all p<0.005), and one-IL-6-was associated with early stage EOC (p<0.0001). Heat shock protein 90kDa beta member 1 (HSP90B1, gp96) was associated with EOC and early stage EOC with borderline statistical significance (p=0.039 and p=0.026, respectively). However, when adjusted for (CA-125), only HSP90B1 independently predicted EOC (p=0.008), as well as early stage EOC (p=0.014).

CONCLUSIONS

Multiple plasma cytokines, including IFNγ, IL-6, IL-8, IL-10, TNFα, PlGF, and HSP90B1 are associated with EOC. Of these, HSP90B1 is associated with EOC independent from the biomarker CA-125.

Autoantibody signature for the serologic detection of ovarian cancer

Sera from patients with ovarian cancer contain autoantibodies (AAb) to tumor-derived proteins that are potential biomarkers for early detection. To detect AAb, we probed high-density programmable protein microarrays (NAPPA) expressing 5177 candidate tumor antigens with sera from patients with serous ovarian cancer (n = 34 cases/30 controls) and measured bound IgG. Of these, 741 antigens were selected and probed with an independent set of ovarian cancer sera (n = 60 cases/60 controls). Twelve potential autoantigens were identified with sensitivities ranging from 13 to 22% at >93% specificity. These were retested using a Luminex bead array using 60 cases and 60 controls, with sensitivities ranging from 0 to 31.7% at 95% specificity. Three AAb (p53, PTPRA, and PTGFR) had area under the curve (AUC) levels >60% (p < 0.01), with the partial AUC (SPAUC) over 5 times greater than for a nondiscriminating test (p < 0.01). Using a panel of the top three AAb (p53, PTPRA, and PTGFR), if at least two AAb were positive, then the sensitivity was 23.3% at 98.3% specificity. AAb to at least one of these top three antigens were also detected in 7/20 sera (35%) of patients with low CA 125 levels and 0/15 controls. AAb to p53, PTPRA, and PTGFR are potential biomarkers for the early detection of ovarian cancer.

Serum autoantibody measurement for the detection of hepatocellular carcinoma

Background

Individuals with liver disease, and especially those with Hepatitis B or C, are at an increased risk of developing hepatocellular carcinoma (HCC) which is the third most common cause of cancer-related death worldwide. Inadequate screening tests largely account for presentation of advanced tumours and high mortality rates. Early detection of HCC amongst high-risk groups is paramount in improving prognosis. This research aimed to further characterise the previously described humoral immune response raised to tumour-associated antigens (TAAs) in the serum of patients with HCC.

Methods

Serum from 96 patients with confirmed HCC, 96 healthy controls matched for age and sex, 78 patients with confirmed liver cirrhosis and 91 patients with confirmed chronic liver disease were analysed for the presence of IgG autoantibodies raised to 41 recombinant TAAs/antigen fragments by ELISA.

Results

Varying autoantibody specificities (97–100%) and sensitivities (0–10%) were observed to individual TAAs. A 21-antigen panel achieved a specificity of 92% and sensitivity of 45% for the detection of HCC. This same panel identified 21% of 169 high-risk controls as having elevated autoantibody levels. A reproducible panel of 10 antigens achieved a specificity of 91% and sensitivity of 41% in HCC. 15% of 152 high-risk controls gave positive results with this panel.

Conclusions

This minimally invasive blood test has the potential to offer advantages over currently available tools for the identification of HCC amongst pre-disposed patients. Results are comparable to current gold standards in HCC (Ultrasonography) and to similar tests in other cancers (EarlyCDT-Lung).

The immunomodulating roles of glycoproteins in epithelial ovarian cancer

The complexity of the immune system demands an intricate defense mechanism by tumors. Ovarian and other tumors employ specific glycoproteins and the associated glycan sequences to modulate immune responses. Glycoproteins enable tumor cells that express or secrete these molecules to evade immune cell attack and induce the immune system to promote tumor growth. This review focuses first on the immune environment in ovarian cancer, and the mechanisms of activation and inhibition that immune cells undergo in order to either attack or ignore a target cell. Next we illustrate the immunomodulatory roles of ovarian cancer-associated glycans and glycoproteins in 1. preventing immune synapse formation, 2. serving as ligands of immune cell receptors, 3. scavenging cytokines and chemokines, and 4. participating in the formation of autoantibodies against the tumor. The importance of these immunomodulating strategies from the view points of understanding the tumor immunology of ovarian tumors, potential origin of such mechanisms, and specific strategies to circumvent the glycoconjugate-mediated suppression of immune responses is discussed in this review.

Upregulation of CD9 in ovarian cancer is related to the induction of TNF-α gene expression and constitutive NF-κB activation

Ovarian cancer is a gynecological cancer with a high death rate. We utilized global gene expression profiles of ovarian carcinomas obtained by complementary DNA (cDNA) microarray to identify ovarian cancer-specific proteins. CD9 was upregulated in ovarian carcinomas, and overexpression of the CD9 protein was detected in ovarian carcinomas by immunohistochemistry. CD9 was also overexpressed in several cancer cell lines, including ovarian cancer cells. In order to elucidate the biological significance of highly expressed CD9 in cancer cells, functional studies of CD9 were performed by ectopic expression, knockdown of CD9 using small interfering RNA (siRNA) and blockage of CD9 activity using the CD9-specific monoclonal antibody ALB6. Ectopic CD9 induced cell survival. In order to identify signaling pathways related to CD9, the gene expressions of CD9/SKOV3 cells were analyzed by cDNA microarray. Among the many upregulated genes, tumor necrosis factor (TNF)-α was induced in CD9/SKOV3 cells. The effect of overexpressed CD9 on the downstream signaling events of TNF-α was further investigated. In CD9/SKOV3 cells, the nuclear factor-kappaB (NF-κB)-signaling pathway was constitutively activated. Knockdown of CD9 by siRNA and blockage of CD9 activity by ALB6 in ovarian cancer cells demonstrated that constitutive activation of NF-κB is CD9 dependent and that CD9 is involved in anti-apoptosis. A CD9 functional study was performed in an ovarian cancer-xenograft mouse by injecting ALB6 into the peritoneum. ALB6 resulted in reduced tumor weight compared with that of control IgG(1). Collectively, these results demonstrate that CD9 functions as an oncogene and represents a target for the development of cancer-specific therapeutics.

Split T cell tolerance against a self/tumor antigen: spontaneous CD4+ but not CD8+ T cell responses against p53 in cancer patients and healthy donors

Analyses of NY-ESO-1-specific spontaneous immune responses in cancer patients revealed that antibody and both CD4⁺ and CD8⁺ T cell responses were induced together in cancer patients. To explore whether such integrated immune responses are also spontaneously induced for other tumor antigens, we have evaluated antibody and T cell responses against self/tumor antigen p53 in ovarian cancer patients and healthy individuals. We found that 21% (64/298) of ovarian cancer patients but no healthy donors showed specific IgG responses against wild-type p53 protein. While none of 12 patients with high titer p53 antibody showed spontaneous p53-specific CD8⁺ T cell responses following a single in vitro sensitization, significant p53-specific IFN-γ producing CD4⁺ T cells were detected in 6 patients. Surprisingly, similar levels of p53-specific CD4⁺ T cells but not CD8⁺ T cells were also detected in 5/10 seronegative cancer patients and 9/12 healthy donors. Importantly, p53-specific CD4⁺ T cells in healthy donors originated from a CD45RA⁻ antigen-experienced T cell population and recognized naturally processed wild-type p53 protein. These results raise the possibility that p53-specific CD4⁺ T cells reflect abnormalities in p53 occurring in normal individuals and that they may play a role in processes of immunosurveillance or immunoregulation of p53-related neoplastic events.

Comparison of candidate serologic markers for type I and type II ovarian cancer

OBJECTIVE

To examine the value of individual and combinations of ovarian cancer associated blood biomarkers for the discrimination between plasma of patients with type I or II ovarian cancer and disease-free volunteers.

METHODS

Levels of 14 currently promising ovarian cancer-related biomarkers, including CA125, macrophage inhibitory factor-1 (MIF-1), leptin, prolactin, osteopontin (OPN), insulin-like growth factor-II (IGF-II), autoantibodies (AAbs) to eight proteins: p53, NY-ESO-1, p16, ALPP, CTSD, B23, GRP78, and SSX, were measured in the plasma of 151 ovarian cancer patients, 23 with borderline ovarian tumors, 55 with benign tumors and 75 healthy controls.

RESULTS

When examined individually, seven candidate biomarkers (MIF, Prolactin, CA-125, OPN, Leptin, IGF-II and p53 AAbs) had significantly different plasma levels between type II ovarian cancer patients and healthy controls. Based on the receiver operating characteristic (ROC) curves constructed and area under the curve (AUC) calculated, CA125 exhibited the greatest power to discriminate the plasma samples of type II cancer patients from normal volunteers (AUC 0.9310), followed by IGF-II (AUC 0.8514), OPN (AUC 0.7888), leptin (AUC 0.7571), prolactin (AUC 0.7247), p53 AAbs (AUC 0.7033), and MIF (AUC 0.6992). p53 AAbs levels exhibited the lowest correlation with CA125 levels among the six markers, suggesting the potential of p53 AAbs as a biomarker independent of CA125. Indeed, p53 AAbs increased the AUC of ROC curve to the greatest extent when combining CA125 with one of the other markers. At a fixed specificity of 100%, the addition of p53 AAbs to CA125 increased sensitivity from 73.8% to 85.7% to discriminate type II cancer patients from normal controls. Notably, seropositivity of p53 AAbs is comparable in type II ovarian cancer patients with negative and positive CA125, but has no value for type I ovarian cancer patients.

CONCLUSIONS

p53 AAbs might be a useful blood-based biomarker for the detection of type II ovarian cancer, especially when combined with CA125 levels.

Autoantibodies to tumor-associated antigens in breast carcinoma

Autoantibodies (AAbs) to tumor-associated antigens (TAAs) have been identified in the circulation of patients with cancer. This paper will focus on recent knowledge related to circulating AAbs to TAAs in breast carcinoma. So far, the following TAAs have been identified to elicit circulating AAbs in breast carcinoma: p53, MUC-1, heat shock proteins (HSP-27, HSP-60, and HSP-90), HER2/neu/c-erb B2, GIPC-1, c-myc, c-myb, cancer-testis antigens (NY-ESO-1), BRCA1, BRCA2, endostatin, lipophilin B, cyclin B1, cyclin D1, fibulin, insulin-like growth factor binding protein 2 (IGFBP-2), topoisomerase II alpha (TOPO2α), and cathepsin D. Measurement of serum AAbs to one specific TAA only is of little value for screening and early diagnosis of breast carcinoma; however, assessment of AAbs to a panel of TAAs may have promising diagnostic potential.