Evaluation of serum autoantibodies against tumor-associated antigens as biomarkers in lung cancer.

We evaluated autoantibodies against nine tumor-associated antigens, including p62, p16, Koc, p53, Cyclin B1, Cyclin E, Survivin, HCC1, and RalA as serological markers in lung cancer. Enzyme-linked immunosorbent assay (ELISA) was used to detect autoantibodies in sera from 50 lung cancer patients and 42 normal controls. Then, four tumor-associated antigens of higher values were selected and validated in sera from validation group. Western blot and serum absorption test were used to confirm positive findings from ELISA. When cutoff values were set as mean optical density values plus 3 standard deviation of normal controls, the positive rate of autoantibodies against four tumor-associated antigens (Survivin, Cyclin B1, HCC1, and p53) reached 32%, 20%, 22%, and 18%, with area under the curve values of 0.653, 0.767, 0.622, and 0.623 in sera from 50 lung cancer, respectively (all p < 0.05). Results from the validation group confirmed the results. When lung cancer patients were divided by their clinicopathological characteristics into different subgroups, we have found that serum anti-Cyclin B1 and anti-HCC1 autoantibodies increased in stages 1, 2, and 3 lung cancer; anti-Survivin autoantibodies increased in stages 2 and 3 lung cancer; and anti-p53 autoantibody only increased in stage 1 when compared with their corresponding levels in controls (all p < 0.05). Serum anti-Cyclin B1 and anti-Survivin autoantibodies increased with disease histological grade 2 and 3 (both p < 0.05). And higher serum level of anti-p53 autoantibodies is positively associated with tumor size. Parallel utilization of these four anti-tumor-associated antigens (any positive) can increase sensitivity to 65.0% at 100% specificity with area under the curve of 0.908 ( p < 0.001) in lung cancer detection in validation group. Our results suggest that autoantibodies against these four tumor-associated antigens have higher values in lung cancer detection, and serum anti-Cyclin-B1 has the potential to serve as novel non-invasive biomarkers in early-stage lung cancer.

Effects of an irinotecan derivative, ZBH­1208, on the immune system in a mouse model of brain tumor and its antitumor mechanism.

The present study aimed to evaluate the inhibitory effects of an irinotecan derivative, ZBH­1208, on brain tumors, and to explore the underlying molecular mechanisms. To determine the effects of ZBH­1208, a brain tumor mouse model was established by transplanting B22 cells. Subsequently, the visceral indices of immune organs and white blood cell counts were determined, and the effects of ZBH­1208 on the expression levels of cell cycle­related proteins were assessed by western blotting. The tumor inhibition rates of 20 and 40 mg/kg ZBH­1208 were 11.7 and 54.1%, respectively. Compared with the negative control group, ZBH­1208 barely affected visceral indices or white blood cell count. Furthermore, the expression levels of p53, p21, cyclin­dependent kinase 7 (CDK7), Wee1, phosphorylated (p)­cell division cycle 2 (CDC2) (Tyr15), p­CDC2 (Thr161) and cyclin B1 proteins were upregulated, whereas the expression levels of cyclin E were downregulated, and those of CDC2, CDK2 and CDC25C were barely altered. In conclusion, the present study demonstrated that ZBH­1208 suppressed the growth of B22 mouse brain tumor xenografts, but did not affect their visceral indices or white blood cell counts. It was suggested that ZBH­1208 exerted its effects by regulating the expression of p53, p21, Wee1, p­CDC2 (Tyr15) and cyclin E proteins.

Tumour-Associated Autoantibodies as Diagnostic Biomarkers for Breast Cancer: A Systematic Review and Meta-Analysis.

Tumour-associated autoantibodies may be promising biomarkers that could facilitate breast cancer (BC) diagnosis and improve patient outcomes. This review aims to identify the tumour-associated autoantibodies with the greatest diagnostic potential. Systematic searches were conducted using PubMed and Web of Science. The most studied tumour-associated autoantibody was included in a meta-analysis, and its clinical value was determined using Fagan's nomogram. The analysis included 84 studies regarding tumour-associated autoantibodies with the diagnostic value. Anti-p53 antibody was the most frequently studied autoantibody, followed by autoantibodies against MUC1, HER2 and cyclin B1. Although individual tumour-associated autoantibodies showed low diagnostic sensitivity, combinations of autoantibodies offered relatively high sensitivity. Enzyme-linked immunosorbent assay (ELISA) was the most common detection method, and nucleic acid programmable protein microarrays appeared preferable to common protein microarrays. As the most commonly studied autoantibody, anti-p53 antibody was included in a meta-analysis. When it had been detected using ELISA and cut-off values were defined as the mean +2 or 3 standard deviations, the summary area under the receiver operating characteristic curve for the presence of BC was 0.78. Fagan's nomogram showed post-test probabilities of 32% and 6% for positive and negative results, respectively. Mammography might be supplemented by the use of tumour-associated autoantibodies as biomarkers for BC diagnosis in younger women with increased risks of BC. Even though several studies have investigated the diagnostic use of tumour-associated autoantibodies as biomarkers for BC detection, a high-quality prospective study is needed to validate their diagnostic value in practice.

The Tumor Antigen Cyclin B1 Hosts Multiple CD4 T Cell Epitopes Differently Recognized by Pre-Existing Naive and Memory Cells in Both Healthy and Cancer Donors.

Cyclin B1 (CCNB1) is considered as a potential target for a cancer vaccine, as it is overexpressed in many malignant cells, while being transiently expressed in normal cells. To evaluate the CD4 T cell response to CCNB1, we derived T cell lines by multiple weekly rounds of stimulation with recombinant CCNB1 of T cells collected in healthy donors (long-term T cell assays). T cell lines were specific for 15 immunodominant peptides and derived preferentially from naive T cells. From 74 overlapping peptides, 20 peptides were selected for their broad specificity of binding to HLA class II molecules and included most of the immunodominant epitopes. They primed in vitro a large number of specific CD4 T cell lines in all the donors. Immunodominant epitopes were the most efficacious in long-term T cell assays, both in terms of number of specific T cell lines and number of responding donors. The 20 peptides were also submitted to short-term T cell assays using cells collected in healthy and cancer patients with the aim to evaluate the memory response. The recognized peptides differed from the immunodominant peptides and were part of the best promiscuous peptides. We also observed pre-existing CCNB1-specifc IgG Abs in both healthy and cancer donors. Long- and short-term T cell assays revealed that CCNB1 contained many CD4 T cell epitopes, which are differentially recognized by pre-existing naive and memory CD4 T cells. These observations are of value for the design of cancer vaccines.

Detection of autoantibodies to multiple tumor-associated antigens (TAAs) in the immunodiagnosis of breast cancer.

We aimed to evaluate the immunodiagnostic values of autoantibodies to a panel of six tumor-associated antigens (TAAs) in the detection of patients with breast cancer. This study determines whether a panel of multiple TAAs would enhance antibody detection and be a useful approach in breast cancer detection and diagnosis. The panel of multiple TAAs was composed of six TAAs including Imp1, p16, Koc, survivin, cyclin B1, and c-myc full-length recombinant proteins. Enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies against these six TAAs in 49 sera from patients with breast cancer, 35 sera from patients with benign breast tumor, and 38 sera from normal individuals. Antibody frequency to any individual TAA in breast cancer was variable and ranged from 12.2 to 18.4%. With the successive addition of TAAs to a final total of six antigens, there was a stepwise increase of positive antibody reactions reaching a sensitivity of 67.3% and a specificity of 92.2% in breast cancer. Positive and negative likelihood ratios were 8.52 and 0.36, respectively, which showed that the clinical diagnostic value of a parallel assay of six TAAs was high. Positive and negative predictive values were, respectively, 91.7 and 68.6%, indicating that the parallel assay of six TAAs raised the diagnostic accuracy greatly. Agreement rate and kappa value were 78.1% and 0.57, respectively, which indicated that the observed value of this assay had a middle range of coincidence with the actual value. The data from this study further support our previous hypothesis that the detection of autoantibodies for diagnosis of a certain type of cancer can be enhanced by using a panel of several carefully selected TAAs as target antigens and a panel of multiple TAAs would be a useful approach in the detection and diagnosis of breast cancer.

Preferential autoimmune response in prostate cancer to cyclin B1 in a panel of tumor-associated antigens.

Previous studies have demonstrated that sera from patients with prostate cancer (PCa) contain autoantibodies that react with tumor-associated antigens (TAAs). Autoantibodies to cyclin B1 and fourteen other TAAs were detected by enzyme-linked immunosorbent assay (ELISA) and Western blotting in 464 sera from patients with PCa, benign prostatic hyperplasia (BPH), and other controls. Autoantibodies to cyclin B1 were detected in 31.0% of sera from randomly selected patients with PCa versus 4.8% in sera with BPH. In the further analysis, 31.4% of sera from PCa patients at the early stage contained anti-cyclin B1 autoantibody, and even 29.4% of patients who had normal prostate-specific antigen (PSA) levels in their serum samples were observed anti-cyclin B1 positive. The cumulative positive rate of autoantibodies against seven selected TAAs (cyclin B1, survivin, p53, DFS70/LEDGFp75, RalA, MDM2, and NPM1) in PCa reached 80.5%, significantly higher than that in normal control sera. In summary, autoantibody to cyclin B1 might be a potential biomarker for the immunodiagnosis of early stage PCa, especially useful in patients with normal PSA level. This study further supports the hypothesis that a customized TAA array can be used for enhancing anti-TAA autoantibody detection, and it may constitute a promising and powerful tool for immunodiagnosis of PCa.

Higher levels of antibodies to the tumour-associated antigen cyclin B1 in cancer-free individuals than in patients with breast cancer.

Cyclin B1 is a checkpoint protein that regulates cell division from G2 to the M phase. Studies in mice have shown that cyclin B1 vaccine-induced immunity significantly delayed or prevented the spontaneous cancer development later in life. We hypothesized that if these results showing a protective effect of anti-cyclin B1 antibodies could be extrapolated to the human condition, cancer-free individuals should have higher levels of endogenous antibodies than patients with cancers characterized by the over-expression of this tumour-associated antigen. To test this hypothesis, we characterized a large (1739 subjects) number of multi-ethnic patients with breast cancer (which over-expresses cyclin B1) and matched controls for anti-cyclin B1 immunoglobulin (Ig)G antibodies. Multivariate analyses, after adjusting for the covariates, showed that cancer-free individuals had significantly higher levels of naturally occurring IgG antibodies to cyclin B1 than patients with breast cancer (mean ± standard deviation: 148·0 ± 73·6 versus 126·1 ± 67·8 arbitrary units per ml; P < 0·0001). These findings may have important implications for cyclin B1-based immunotherapy against breast cancer and many other cyclin B1-over-expressing malignancies.

Autoantibody detection to tumor-associated antigens of P53, IMP1, P16, cyclin B1, P62, C-myc, Survivn, and Koc for the screening of high-risk subjects and early detection of esophageal squamous cell carcinoma.

The aim of this study was to evaluate the diagnostic values by detecting sera autoantibodies to eight tumor-associated antigens (TAAs) of P53, IMP1, P16, cyclin B1, P62, C-myc, Survivn and Koc full-length recombinant proteins for the screening of high-risk subjects and early detection of esophageal squamous cell carcinoma (ESCC). Enzyme-linked immunosorbent assay was used to detect autoantibodies against the eight selected TAAs in 567 sera samples from four groups, including 200 individuals with normal esophageal epithelia (NOR), 214 patients with esophageal basal cell hyperplasia (BCH), 65 patients with esophageal dysplasia (DYS), and 88 patients with ESCC. In addition, the expression of the eight antigens in esophageal tissues was analyzed by immunohistochemistry. Statistically significant distribution differences were identified among the four groups for each of the individual autoantibodies to six TAAs (P53, IMP1, P16, cyclin B1, P62, and C-myc); the detection rates of antoantibodies were positively correlated with the progression of ESCC. When autoantibody assay successively accumulated to six TAAs (P53, IMP1, P16, cyclin B1, P62, and C-myc), a stepwise increased detection frequency of autoantibodies was found in the four sera groups (6% in NOR, 18% in BCH, 38% in DYS, and 64% in ESCC, respectively), the risks to BHC, DYS, and ESCC steadily increased about 3-, 9-, and 27-folds. The sensitivity and the specificity for autoantibodies against the six TAAs in diagnosing ESCC reached up to 64% and 94%, respectively. The area under the receiver operating characteristic curve for the six anti-TAA autoantibodies was 0.78 (95% confidence interval 0.74-0.83). No more increasing in sensitivity was found with the addition of new anti-TAA autoantibodies. A combination detection of autoantibodies to TAAs might distinguish ESCC patients from normal individuals and the patients with esophageal precancerous lesions.

Role of fatty-acid synthesis in dendritic cell generation and function.

Dendritic cells (DC) are professional APCs that regulate innate and adaptive immunity. The role of fatty-acid synthesis in DC development and function is uncertain. We found that blockade of fatty-acid synthesis markedly decreases dendropoiesis in the liver and in primary and secondary lymphoid organs in mice. Human DC development from PBMC precursors was also diminished by blockade of fatty-acid synthesis. This was associated with higher rates of apoptosis in precursor cells and increased expression of cleaved caspase-3 and BCL-xL and downregulation of cyclin B1. Further, blockade of fatty-acid synthesis decreased DC expression of MHC class II, ICAM-1, B7-1, and B7-2 but increased their production of selected proinflammatory cytokines including IL-12 and MCP-1. Accordingly, inhibition of fatty-acid synthesis enhanced DC capacity to activate allogeneic as well as Ag-restricted CD4(+) and CD8(+) T cells and induce CTL responses. Further, blockade of fatty-acid synthesis increased DC expression of Notch ligands and enhanced their ability to activate NK cell immune phenotype and IFN-γ production. Because endoplasmic reticulum (ER) stress can augment the immunogenic function of APC, we postulated that this may account for the higher DC immunogenicity. We found that inhibition of fatty-acid synthesis resulted in elevated expression of numerous markers of ER stress in humans and mice and was associated with increased MAPK and Akt signaling. Further, lowering ER stress by 4-phenylbutyrate mitigated the enhanced immune stimulation associated with fatty-acid synthesis blockade. Our findings elucidate the role of fatty-acid synthesis in DC development and function and have implications to the design of DC vaccines for immunotherapy.

A genetic variant of FcγRIIIa is strongly associatedwith humoral immunity to cyclin B1 in African American patients with prostate cancer.

There are significant inter-individual differences in naturally occurring antibody responses to the tumor-associated antigen cyclin B1 in healthy subjects with no history of cancer as well as in patients with multiple types of cancer, but the host genetic factors that might contribute to these differences have not been identified. The aim of the present investigation was to determine whether the variation in endogenous antibody levels to cyclin B1 in patients with prostate cancer was associated with immunoglobulin GM and KM alleles, expressed on the constant regions of γ and κ chains, respectively. We also aimed to determine whether particular Fcgamma receptor (FcγR) genotypes, which have been implicated in the immunobiology of several cancers, contribute to the magnitude of humoral immunity to cyclin B1. DNA samples from 129 Caucasian American (CA) and 76 African American (AA) patients with prostate cancer were genotyped for several GM, KM, and FcγR alleles. Plasma samples from these subjects were also characterized for IgG antibodies to cyclin B1. No significant associations were found between any genetic markers and the level of anticyclin B1 antibodies in CA patients. In AA patients, however, homozygosity for the valine allele at the FcγRIIIa locus was strongly associated with low antibody responsiveness to cyclin B1 (p = 0.0007). Since immunity to cyclin B1 has been shown to play a protective role, these results may, at least in part, explain the disproportionately higher rate of mortality in AA patients with prostate cancer.

Evaluation of known oncoantibodies, HER2, p53, and cyclin B1, in prediagnostic breast cancer sera.

Serum autoantibodies, directed against oncogenic proteins, have been frequently detected in the sera of patients with breast cancer. It is unknown whether serum antibodies that are identified in patients with established disease could also be detected in patients with newly diagnosed disease or even predate the diagnosis of breast cancer. Using sera collected at the time of treatment, at the time of diagnosis, or before the time of diagnosis, the current study aimed to address the temporal relationship between breast cancer development and serum antibody response. Starting from serum antibodies to eight known breast cancer antigens, we first identified four serum antibodies, HER2/neu, p53, carcinoembryonic antigen (CEA), and cyclin B1, which are significantly increased in the sera collected from patients with breast cancer at the time of treatment. These antibodies were also elevated in breast cancer sera collected at the time of diagnosis. Finally, comparison of antibody responses in prediagnostic samples from women before the development of breast cancer and in controls showed that antibodies to the HER2/neu and p53 can be detected in sera that were collected on average more than 150 days before a breast cancer diagnosis. These results showed that serum autoantibodies commonly reported in sera from patients with established disease can also be detected in prediagnostic sera and may be useful for the early detection of breast cancer.

Tumor associated antigen specific T-cell populations identified in ex vivo expanded TIL cultures.

Ex vivo expanded tumor infiltrating lymphocytes (TILs) from malignant melanoma (MM) and head & neck squamous cell carcinoma (HNSCC) share a similar oligoclonal composition of T effector memory cells, with HLA class I restricted lysis of tumor cell lines. In this study we show that ex vivo expanded TILs from MM and HNSCC demonstrate a heterogeneous composition in frequency and magnitude of tumor associated antigen specific populations by Elispot IFNγ quantitation. TILs from MM and HNSCC shared reactivity towards NY ESO-1, cyclin B1 and Bcl-x derived peptides. Additionally we show that dominating T-cell clones and functionality persists through out expansion among an oligoclonal composition of T-cells. Our findings mirror prior results on the oligoclonal composition of TIL cultures, further indicating a potential for a broader repertoire of specific effector cells recognizing the heterogeneous tumors upon adoptive transfer; increasing the probability of tumor control by minimizing immune evasion by tumor cell escape variants.

CDC23 regulates cancer cell phenotype and is overexpressed in papillary thyroid cancer.

Cancer gender disparities have been observed for a variety of human malignancies. Thyroid cancer is one such example where there is a dramatic difference in the incidence, aggressiveness, and death rate by gender. The molecular basis for gender disparity is poorly understood. To address this, we performed genome-wide gene expression profiling in matched papillary thyroid cancer (PTC) samples and identified nine candidate genes differentially expressed by gender. One of these genes was CDC23 that was upregulated in PTC in men compared with women. Because the function and expression of CDC23 is unknown in eukaryotic cells, we further characterized the expression of CDC23 in normal, hyperplastic, and PTC tissue samples. We found CDC23 was overexpressed in PTC and absent in normal and hyperplastic thyroid tissue. In thyroid cancer cells, functional knockdown of CDC23 resulted in an increase in the number of cells in both the S and G(2)M phases of the cell cycle, and an inhibition of cellular proliferation, tumor spheroid formation, and anchorage-independent growth. Cellular arrest in both S and G(2)M phases was associated with significant cyclin B1 and securin protein accumulation after CDC23 knockdown. Moreover, the effect of CDC23 on cellular proliferation and cell cycle progression was reversed on triple knockdown studies of CDC23, cyclin B1, and securin. Our data taken together suggests CDC23 has important biologic effects on cell proliferation and cell cycle progression. The effect of CDC23 on cellular proliferation and cell cycle progression is mediated, at least in part, by cyclin B1 and securin protein levels. Therefore, we propose that CDC23 is a critical regulator of cell cycle and cell growth, and may be involved in thyroid cancer initiation and progression, and may explain the different tumor biology observed by gender.

Identification of a cyclin B1-derived CTL epitope eliciting spontaneous responses in both cancer patients and healthy donors.

With the aim to identify cyclin B1-derived peptides with high affinity for HLA-A2, we used three in silico prediction algorithms to screen the protein sequence for possible HLA-A2 binders. One peptide scored highest in all three algorithms, and the high HLA-A2-binding affinity of this peptide was verified in an HLA stabilization assay. By stimulation with peptide-loaded dendritic cells a CTL clone was established, which was able to kill two breast cancer cell lines in an HLA-A2-dependent and peptide-specific manner, demonstrating presentation of the peptide on the surface of cancer cells. Furthermore, blood from cancer patients and healthy donors was screened for spontaneous T-cell reactivity against the peptide in IFN-γ ELISPOT assays. Patients with breast cancer, malignant melanoma, or renal cell carcinoma hosted powerful and high-frequency T-cell responses against the peptide. In addition, when blood from healthy donors was tested, similar responses were observed. Ultimately, serum from cancer patients and healthy donors was analyzed for anti-cyclin B1 antibodies. Humoral responses against cyclin B1 were frequently detected in both cancer patients and healthy donors. In conclusion, a high-affinity cyclin B1-derived HLA-A2-restricted CTL epitope was identified, which was presented on the cell surface of cancer cells, and elicited spontaneous T-cell responses in cancer patients and healthy donors.

Evaluation of serum autoantibody levels in the diagnosis of ovarian endometrioma.

OBJECTIVE: We analyzed autoantibodies against tumor-associated antigens (TAAs) in the serum of patients with endometrioma and healthy controls to determine whether autoantibodies can be accurate biomarkers for the diagnosis of ovarian endometrioma. METHODS: Serum samples were obtained from 56 patients with endometriosis and 66 healthy women who served as normal controls. The titers of antibodies against a panel of eight TAAs were analyzed using enzyme-linked immunosorbent assay. RESULTS: We found that the serum IGFII mRNA-binding protein 1 (IMP1) autoantibody and cyclin B1 autoantibody could discriminate between healthy controls and endometriosis patients (AUC-ROC 0.777; 95% confidence interval [CI] 0.694-0.860, P<0.0005, and AUC-ROC 0.614; 95%confidence interval [CI] 0.513-0.714, P=0.031, respectively). Using 0.073 and 0.007 as the cutoff values for IMP1 and Cyclin B1 autoantibody, respectively, the sensitivity and specificity of IMP1 were 85.7 and 63.6%, respectively. When cylcin B1 was combined with IMP1, the specificity increased to 72.7% and the sensitivity slightly decreased to 83.9%. CONCLUSIONS: Our data suggest that IMP1 alone or combined with cyclin B1 seems to fulfill the requirements of sensitivity and specificity to become a useful clinical biomarker of endometrioma. However, further studies will be required to establish the predictive value and to support the clinical use of IMP1/cyclin B1 in the diagnosis and/or screening of endometriosis.

Oral administration of caffeine during voluntary exercise markedly decreases tissue fat and stimulates apoptosis and cyclin B1 in UVB-treated skin of hairless p53-knockout mice.

Treatment of p53(-/-) mice orally with caffeine, voluntary exercise or their combination for 2 weeks prior to a single irradiation with UVB (i) decreased the weight of the epididymal fat pads by 22, 40 and 56%, (ii) decreased the thickness of the dermal fat layer by 10, 26 and 42%, (iii) increased the number of apoptotic sunburn cells by 29, 100 and 489%, (iv) increased the number of caspase-3-positive cells by 33, 117 and 667% and (v) increased the number of mitotic cells with cyclin B1-positive staining by 40, 210 and 510%, respectively. Pearson's correlation coefficient indicated a statistically significant inverse relationship between the level of tissue fat and the number of mitotic cells with cyclin B1 in p53(-/-) mice but not in p53(+/+) littermates. Western blot analysis indicated that treatment of p53(-/-) mice with caffeine together with exercise increased the level of cyclin B1 significantly more than in p53(+/+) mice. p53(-/-) mice, but not p53(+/+) mice, treated with caffeine during exercise exhibited a dramatic decrease in the level of survivin. Our results suggest that voluntary exercise in combination with oral caffeine may exert a synergistic increase in UVB-induced apoptosis and that tissue fat may be a more important modulator of apoptosis and carcinogenesis in p53-deficient mice than in p53-normal mice. The stimulatory effects on apoptosis in p53(-/-) mice by the combination treatment might be associated with increased levels of cyclin B1 and decreased levels of survivin.