Detecting of p16 Autoantibody as a Potential Early Diagnostic Serum Biomarker in Patients with Cervical Cancer.

BACKGROUND: Over-expression of tumor-associated antigens (TAAs) may trigger secretion of their auto-antibodies. The present work was designed to test whether circulating antibody to P16 protein-derived antigens was altered in cervical cancer. METHODS: 141 cases of cervical cancer patients, 133 cases of cervical benign tumor patients, and 153 healthy volunteers matched in age were recruited. The level of circulating P16 auto-antibody was tested using an ELISA developed in-house with linear peptide antigens derived from the P16 protein. RESULTS: The P16 auto-antibody in the malignant tumor group had a significantly higher level than the healthy control group and the benign tumor group (t = 4.016, p < 0.001; t = 3.879, p < 0.001). Patients with stage I cervical cancer have the highest level of P16 autoantibody and the sensitivity against > 90% specificity was 20.3%. CONCLUSIONS: The circulating auto-antibody to P16 may be one of a series of potential biomarkers with early prognostic values for cervical cancer.

A panel of autoantibodies as potential early diagnostic serum biomarkers in patients with cervical cancer.

The study was designed to test whether circulating autoantibodies against associated antigens (TAAs) were altered in early cervical cancer and benign cervical tumors. A total of 111 cervical cancer patients, 137 cervical benign tumor patients, and 160 healthy volunteers matched in age were recruited in this study. The expression of autoantibodies was tested using in-house developed enzyme-linked immunosorbent assay (ELISA) with linear peptide envelope antigens derived from TAAs. One-way ANOVA test showed that there was no difference in the CD25 autoantibody expression among the cervical cancer group, benign tumor group, and healthy control group (P = 0.063; P = 0.191). The expression of autoantibodies against survivin and TP53 in the cervical cancer group was significantly higher than that in the benign tumor group (P < 0.001; P < 0.001). The levels of autoantibodies against cyclinB-1 and ANXA-1 were higher in the cervical cancer group than in the healthy control group (P = 0.010; P = 0.001), while autoantibodies in the cervical cancer group showed no difference in expression compared with that in the benign tumor group. The panel of five TAAs showed a sensitivity of 37.8 % and a specificity of 90 %, which was much higher than the sensitivity of the single-TAA testing group. The data from this study further support our previous hypothesis that the detection of autoantibodies for the diagnosis of a specific cancer type can be enhanced using a panel of several selected TAAs as target antigens.

FOXP3 autoantibody as a potential early prognostic serum biomarker in patients with cervical cancer.

BACKGROUND: Overexpression of tumor-associated antigens has been reported in many types of cancer and may trigger secretion of their autoantibodies. The present work was designed to test whether circulating antibody to FOXP3 protein-derived antigens was altered in early cervical cancer and cervical benign tumors. METHODS: A total of 141 patients with cervical cancer, 133 patients with cervical benign tumors and 148 healthy age-matched volunteers were recruited. The level of circulating anti-FOXP3 IgG antibody was tested using an enzyme-linked immunosorbent assay developed in-house with linear peptide antigens derived from FOXP3 protein. The linear peptide antigens were designed according to the computational prediction of HLA-II epitopes. RESULTS: Student's t test showed that anti-FOXP3 IgG in the malignant tumor group and the benign tumor group was significantly higher than in the control group (t = 6.127, p < 0.001; t = 2.704, p = 0.007). In addition, patients with stage I cervical cancer (t = 2.968, p = 0.003) had a significantly higher level of FOXP3 autoantibodies than patients with benign tumors. The sensitivity against >90 % specificity was 20.6 % with an interassay deviation of 11.7 % in the cervical cancer group. Based on a cut-off value determined by the 98th percentile of the control group IgG levels, the anti-FOXP3 IgG positivity was 2.1 % in patients with cervical cancer compared to 2.0 % in the health controls (chi-squared = 0.004, p = 0.952, OR = 1.051, 95 % CI 0.209-5.295). CONCLUSION: The circulating autoantibody to FOXP3 reflecting the continuous development of the cervical lesion, may be a potential biomarker with early prognostic values for cervical cancer.

Anti-p16 autoantibodies may be a useful biomarker for early diagnosis of esophageal cancer.

AIM: Our recent work suggested that circulating IgG antibodies to a linear peptide derived from p16 protein were significantly increased in patients with lung cancer. The present study was then designed to test whether such autoantibodies were also altered in esophageal cancer. METHODS: An enzyme-linked immunosorbent assay was developed in-house to determine circulating IgA and IgG antibodies against p16 protein-derived antigens in 97 patients with esophageal squamous cell carcinoma (ESCC) and 226 healthy subjects. RESULTS: The levels of anti-p16 IgG but not IgA antibodies were significantly higher in the patient group than the control group (t = 2.81, P = 0.0052); circulating anti-p16 IgG levels were inversely correlated with stages of ESCC (r = -0.30, df = 81, P = 0.0058) and patients with stage I of ESCC had the highest IgG level among all four stages (t = 5.25, P ≤ 0.0001, compared with control subjects). There was no correlation between the levels of IgA and IgG either in the patient group (r = -0.05, df = 86, P = 0.627) or in the control group (r = -0.1, df = 205, P = 0.146). CONCLUSION: Circulating IgG autoantibody to p16 protein may be a potential biomarker for early diagnosis of esophageal cancer.

Detection of circulating antibodies to linear peptide antigens derived from ANXA1 and DDX53 in lung cancer.

The EarlyCDT®-Lung test was the first autoantibody-based diagnostic tool for lung cancer, which was developed with a panel of recombinant protein antigens. To confirm whether the antibody test developed with linear peptide antigens has a similar power to that developed with the whole protein molecules, the present work was then undertaken to develop an in-house enzyme-linked immunosorbent assay with linear peptide antigens derived from annexin A1 (ANXA1) and DEAD box protein 53 (DDX53), which have been used to develop the EarlyCDT®-Lung test. A total of 272 patients with non-small cell lung cancer (NSCLC) and 227 control subjects matched in age and smoking history were recruited. Student's t test showed that the levels of circulating IgG to ANXA1-derived peptide antigens were significantly higher in patients with NSCLC than control subjects (t = 5.66, P < 0.0001), in which the increased anti-ANXA1 IgG levels were observed only in patients at stages I, II, or III, but not in those at stage IV. However, the levels of circulating IgG to DDX53-derived peptide antigens were not significantly altered in NSCLC (t = 1.78, P = 0.076). Receiver operating characteristic analysis showed that the sensitivity against specificity of >90% was 23.7% for ANXA1 IgG assay and 13.8% for DDX53 IgG assay. This work suggests that the linear peptide antigen derived from ANXA1 may be suitable for the development of diagnostic tool for lung cancer although further screening is needed to identify more such peptide antigens derived from tumor-associated antigens.

Autoantibodies against p16 protein-derived peptides may be a potential biomarker for non-small cell lung cancer.

Overexpression of tumor-associated antigens (TAAs) has been reported in many types of cancer and may trigger secretion of their autoantibodies. The present work was thus designed to test whether circulating antibody to p16 protein-derived antigens was altered in lung cancer. Two hundred seventy-one patients with non-small cell lung cancer (NSCLC) and 226 control subjects matched in age, gender, and smoking history were recruited in this study. The levels of circulating anti-p16 IgA and IgG antibodies were tested using an enzyme-linked immunosorbent assay (ELISA) developed in-house with linear peptide antigens derived from p16 protein. Student's t test showed that patients with NSCLC had a significant higher level of anti-p16 IgG antibody than control subjects (t = 2.74, P = 0.0063) but did not have a significant increase in IgA antibody levels (t = 1.92, P = 0.056). The sensitivity against >90% specificity was 19.7% for the IgG assay with an inter-assay deviation of 11.6%, and 10.3% for the IgA assay with an inter-assay deviation of 14.7%. Based on a cut-off value determined by the 99th percentile of control IgG levels, the anti-p16 IgG positivity was 6.7% in patients with NSCLC compared to 0.88% in control subjects (χ (2) = 10.58, P = 0.001, OR = 7.97, 95% CI 1.84­34.85). Circulating anti-p16 IgG levels were increased with stages of NSCLC, and patients with stage IV NSCLC had the highest IgG level among all four stages (t = 2.42, P = 0.016, compared with the control group). Pearson correlation analysis showed a significant correlation between circulating levels of IgA and IgG in the patient group (r = −0.2, df = 236, P = 0.0021) but not in the control group (r = −0.1, df = 205, P = 0.146). Circulating IgG antibody to p16 protein may be a potential biomarker with prognostic values for lung cancer.

Circulating autoantibody to FOXP3 may be a potential biomarker for esophageal squamous cell carcinoma.

The present study was undertaken to develop a relatively quantitative enzyme-linked immunosorbent assay (ELISA) in-house using human leukocyte antigen class II-restricted epitopes in order to test circulating autoantibodies to human forkhead/winged helix transcription factor (FOXP3) as a biomarker for esophageal cancer. A total of 97 patients with esophageal squamous cell carcinoma (ESCC) and 227 healthy subjects were recruited for this study, and their plasma samples were collected for antibody analysis with the ELISA approach. Student's t test showed that the anti-FOXP3 IgG antibody levels were significantly higher in the patient group than the control group (t=6.23, P<0.0001). Based on a cutoff value determined by the mean+3SD of control IgG levels, the positive rate was 5.15 % in patients with ESCC as compared to 0.88 % in control subjects (X (2) =6.53, P=0.019, OR=5.85, 95 % CI 1.12-30.67), in which patients at stage I had the highest positivity (11.54 %, X (2) =12.15, P=0.0005, OR=13.10, 95 % CI 2.09-82.04). The sensitivity against >95 % specificity was 22.7 % for the IgG assay with an inter-assay deviation of 13.35 %. This work suggests that circulating IgG autoantibody to FOXP3 may be a potential biomarker for early diagnosis of esophageal cancer.

An age-dependent reversal in the protective capacities of JNK signaling shortens Caenorhabditis elegans lifespan.

Stress-activated protein kinase (SAPK) pathways are evolutionarily conserved signaling modules that orchestrate protective responses to adverse environmental conditions. However, under certain conditions, their activation can be deleterious. Thus, activation of the c-Jun N-terminal kinase (JNK) SAPK pathway exacerbates a diverse set of pathologies, many of which are typical of old age. The contexts determining whether the outcome of JNK signaling is protective or detrimental are not fully understood. Here, we show that the age of an animal defines such a context. The Caenorhabditis elegans JNK homolog, KGB-1, provides protection from heavy metals and protein folding stress in developing animals. However, we found that with the onset of adulthood, KGB-1 activity becomes detrimental, reducing stress resistance and lifespan. Genetic analyses coupled with fluorescent imaging linked this phenotypic switch to age-dependent antagonistic modulation of DAF-16/FOXO: KGB-1 activation enhanced DAF-16 nuclear localization and transcriptional activity during development but decreased it in adults. Epistasis analyses showed that DAF-16 was necessary and sufficient to explain some of the kgb-1-dependent detrimental phenotypes, but not all. The identification of early adulthood as a point following which the contribution of KGB-1 activity reverses from beneficial to detrimental sheds new light on the involvement of JNK signaling in age-related pathologies. Furthermore, the age-dependent reversal has intriguing implications for our understanding of aging.