JMJD6 Autoantibodies as a Potential Biomarker for Inflammation-Related Diseases.

Inflammation is closely associated with cerebrovascular diseases, cardiovascular diseases, diabetes, and cancers, and it is accompanied by the development of autoantibodies in the early stage of inflammation-related diseases. Hence, it is meaningful to discover novel antibody biomarkers targeting inflammation-related diseases. In this study, Jumonji C-domain-containing 6 (JMJD6) was identified by the serological identification of antigens through recombinant cDNA expression cloning. In particular, JMJD6 is an antigen recognized in serum IgG from patients with unstable angina pectoris (a cardiovascular disease). Then, the serum antibody levels were examined using an amplified luminescent proximity homogeneous assay-linked immunosorbent assay and a purified recombinant JMJD6 protein as an antigen. We observed elevated levels of serum anti-JMJD6 antibodies (s-JMJD6-Abs) in patients with inflammation-related diseases such as ischemic stroke, acute myocardial infarction (AMI), diabetes mellitus (DM), and cancers (including esophageal cancer, EC; gastric cancer; lung cancer; and mammary cancer), compared with the levels in healthy donors. The s-JMJD6-Ab levels were closely associated with some inflammation indicators, such as C-reactive protein and intima-media thickness (an atherosclerosis index). A better postoperative survival status of patients with EC was observed in the JMJD6-Ab-positive group than in the negative group. An immunohistochemical analysis showed that JMJD6 was highly expressed in the inflamed mucosa of esophageal tissues, esophageal carcinoma tissues, and atherosclerotic plaques. Hence, JMJD6 autoantibodies may reflect inflammation, thereby serving as a potential biomarker for diagnosing specific inflammation-related diseases, including stroke, AMI, DM, and cancers, and for prediction of the prognosis in patients with EC.

Stage-Specific Alteration and Prognostic Relationship of Serum Fumarate Hydratase Autoantibodies in Gastric Cancer.

The relationship between energy production and cancer is attracting attention. This study aimed to investigate the clinicopathological significance of fumarate hydratase (FH), a tricarboxylic acid cycle enzyme, in gastric cancer using autoantibodies as biomarkers. The study analyzed 116 patients who underwent gastric cancer surgery and 96 healthy controls. Preoperative serum FH autoantibody (s-FH-Ab) titers were analyzed using an immunosorbent assay with an amplified luminescent proximity homogeneous assay. Receiver operating characteristic analysis was used to determine the cutoff s-FH-Ab titer. Clinicopathological factors and prognosis were compared between the high and low s-FH-Ab groups. The s-FH-Ab levels were significantly higher in the gastric cancer group than in the control group (p = 0.01). Levels were elevated even in patients with stage I gastric cancer compared with healthy controls (p = 0.02). A low s-FH-Ab level was significantly associated with distant metastasis (p = 0.01), peritoneal dissemination (p < 0.05), and poor overall survival (p < 0.01). Multivariate analysis revealed that low s-FH-Ab levels were an independent risk factor for poor prognosis (p < 0.01). Therefore, s-FH-Ab levels may be a useful biomarker for early diagnosis and the prediction of prognosis in patients with gastric cancer.

Combination of high anti-SKI and low anti-TMED5 antibody levels is preferable prognostic factor in esophageal carcinoma.

Given that esophageal cancer is highly malignant, the discovery of novel prognostic markers is eagerly awaited. We performed serological identification of antigens by recombinant cDNA expression cloning (SEREX) and identified SKI proto-oncogene protein and transmembrane p24 trafficking protein 5 (TMED5) as antigens recognized by serum IgG antibodies in patients with esophageal carcinoma. SKI and TMED5 proteins were expressed in Escherichia coli, purified by affinity chromatography, and used as antigens. The serum anti-SKI antibody (s-SKI-Ab) and anti-TMED5 antibody (s-TMED5-Ab) levels were significantly higher in 192 patients with esophageal carcinoma than in 96 healthy donors. The presence of s-SKI-Abs and s-TMED5-Abs in the patients' sera was confirmed by western blotting. Immunohistochemical staining showed that the TMED5 protein was highly expressed in the cytoplasm and nuclear compartments of the esophageal squamous cell carcinoma tissues, whereas the SKI protein was localized predominantly in the nuclei. Regarding the overall survival in 91 patients who underwent radical surgery, the s-SKI-Ab-positive and s-TMED5-Ab-negative statuses were significantly associated with a favorable prognosis. Additionally, the combination of s-SKI-Ab-positive and s-TMED5-Ab-negative cases showed an even clearer difference in overall survival as compared with that of s-SKI-Ab-negative and s-TMED5-Ab-positive cases. The s-SKI-Ab and s-TMED5-Ab biomarkers are useful for diagnosing esophageal carcinoma and distinguishing between favorable and poor prognoses.

Serum anti-PCK1 antibody levels are a prognostic factor for patients with diabetes mellitus.

BACKGROUND: Autoantibodies develop in autoimmune diseases, cancer, diabetes mellitus (DM), and atherosclerosis-related diseases. However, autoantibody biomarkers have not been successfully examined for diagnosis and therapy. METHODS: Serological identification of antigens through recombinant cDNA expression cloning (SEREX) was used for primary screening of antigens. The cDNA product was expressed in bacteria and purified. Amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) was used to evaluate antibody levels in serum samples. RESULTS: Phosphoenolpyruvate carboxykinase 1 (PCK1) was recognized as an antigen by serum IgG antibodies in the sera of patients with atherosclerosis. AlphaLISA showed significantly higher serum antibody levels against recombinant PCK1 protein in patients with DM and cardiovascular disease than in healthy donors, but not in those with acute ischemic stroke, transient ischemic attack, or obstructive sleep apnea syndrome. The area under the receiver operating characteristic curve for anti-PCK1 antibodies was 0.7024 for DM. The serum anti-PCK1 antibody levels were associated with age, platelet count, and blood pressure. Anti-PCK1-antibody-positive patients showed significantly lower overall survival than the negative patients. CONCLUSIONS: Serum anti-PCK1 antibody levels were found to be associated with DM. The anti-PCK1 antibody marker is useful for predicting the overall survival of patients with DM.

Prognostic and diagnostic significance of preoperative Jumonji domain­containing 6 antibodies in colorectal cancer.

Jumonji domain-containing 6 (JMJD6) protein has been reported to be upregulated in different cancer cells; however, to the best of our knowledge, no report has analyzed serum anti-JMJD6 antibodies (s-JMJD6-Abs) in patients with cancer. Therefore, the present study evaluated the clinical significance of s-JMJD6-Abs in patients with colorectal cancer. Preoperative serum samples were analyzed from 167 patients with colorectal cancer who underwent radical surgery between April 2007 and May 2012. The pathological stages were as follows Stage I (n=47), stage II (n=56), stage III (n=49) and stage IV (n=15). In addition, 96 healthy participants were analyzed as controls. s-JMJD6-Abs were analyzed by amplified luminescent proximity homology assay-linked immunosorbent assay. The cutoff value of s-JMJD6-Abs for detecting colorectal cancer was calculated to be 5,720 using the receiver operating characteristic curve. The positive rate of s-JMJD6-Abs was 37% in patients with colorectal cancer (61 of 167), independent of carcinoembryonic antigen or carbohydrate antigen 19-9 and p53-Abs. Clinicopathological factors and prognosis were compared between the s-JMJD6-Abs-positive group and the s-JMJD6-Abs-negative group. The s-JMJD6-Ab-positive status was significantly associated with older age (P=0.03), but was not associated with other clinicopathological variables. Regarding recurrence-free survival, the s-JMJD6-positive status was a significant poor prognostic factor in both univariate (P=0.02) and multivariate (P<0.01) analyses. Similarly, regarding overall survival, the s-JMJD6-Abs-positive status was a significant poor prognostic factor in both univariate (P=0.03) and multivariate (P=0.01) analyses. In conclusion, preoperative s-JMJD6-Abs was positive in 37% of patients with colorectal cancer and may be considered an independent poor prognostic biomarker.

Utility of atherosclerosis-associated serum antibodies against colony-stimulating factor 2 in predicting the onset of acute ischemic stroke and prognosis of colorectal cancer.

Introduction: Autoantibodies against inflammatory cytokines may be used for the prevention of atherosclerosis. Preclinical studies consider colony-stimulating factor 2 (CSF2) as an essential cytokine with a causal relationship to atherosclerosis and cancer. We examined the serum anti-CSF2 antibody levels in patients with atherosclerosis or solid cancer. Methods: We measured the serum anti-CSF2 antibody levels via amplified luminescent proximity homogeneous assay-linked immunosorbent assay based on the recognition of recombinant glutathione S-transferase-fused CSF2 protein or a CSF2-derived peptide as the antigen. Results: The serum anti-CSF2 antibody (s-CSF2-Ab) levels were significantly higher in patients with acute ischemic stroke (AIS), acute myocardial infarction (AMI), diabetes mellitus (DM), and chronic kidney disease (CKD) compared with healthy donors (HDs). In addition, the s-CSF2-Ab levels were associated with intima-media thickness and hypertension. The analyzes of samples obtained from a Japan Public Health Center-based prospective study suggested the utility of s-CSF2-Ab as a risk factor for AIS. Furthermore, the s-CSF2-Ab levels were higher in patients with esophageal, colorectal, gastric, and lung cancer than in HDs but not in those with mammary cancer. In addition, the s-CSF2-Ab levels were associated with unfavorable postoperative prognosis in colorectal cancer (CRC). In CRC, the s-CSF2-Ab levels were more closely associated with poor prognosis in patients with p53-Ab-negative CRC despite the lack of significant association of the anti-p53 antibody (p53-Ab) levels with the overall survival. Conclusion: S-CSF2-Ab was useful for the diagnosis of atherosclerosis-related AIS, AMI, DM, and CKD and could discriminate poor prognosis, especially in p53-Ab-negative CRC.

Serum anti­TSTD2 antibody as a biomarker for atherosclerosis­induced ischemic stroke and chronic kidney disease.

Autoantibodies can be used in the early diagnosis and treatment of atherosclerosis-related diseases. Using ProtoArray® screening of samples from patients with atherosclerosis, the present study identified thiosulfate sulfurtransferase-like domain-containing 2 (TSTD2) as a novel atherosclerosis antigen. The serum TSTD2 antibody levels were then quantified using an amplified luminescent proximity homogeneous assay-linked immunosorbent assay. This demonstrated the levels of TSTD2 antibodies (TSTD2-Abs) to be significantly higher in patients with acute cerebral infarction or chronic kidney disease than in healthy donors. The TSTD2-Ab levels were also found to be higher in males, older adults, smokers, in those who consumed alcohol regularly, and in those with hypertension. Furthermore, Spearman's rank correlation analysis revealed TSTD2-Ab levels to be strongly associated with measures of atherosclerosis severity, including plaque scores, intima-media thickness of the carotid artery and the cardio-ankle vascular index. Thus, TSTD2-Abs may thus be a promising novel biomarker for atherosclerosis-related cerebral infarction and kidney disease.

Serum anti-SERPINE1 antibody as a potential biomarker of acute cerebral infarction.

The presence of disease-specific antigens and autoantibodies in the sera of patients with atherosclerosis-related diseases has been widely reported and is considered to result from inflammation of the arterial wall and the involvement of immune factors. The aim of this study was to identify a novel antibody in patients with ischemic stroke by serological identification of antigens using recombinant cDNA expression cloning from patients who had a transient ischemic attack (TIA). We identified the serpin peptidase inhibitor, clade E member 1 (SERPINE1), as a candidate antigen. The serum anti-SERPINE1 antibody levels quantified using amplified luminescent proximity homogeneous assay-linked immunosorbent assay were significantly higher in patients with ischemic stroke, including those with acute cerebral infarction (aCI), TIA, and chronic cerebral infarction, than in healthy donors. The antibody levels were strongly associated with old age, female sex, and presence of hypertension, diabetes mellitus, and cardiovascular disease. Age and intima-media thickness of the carotid artery were positively correlated with antibody levels, which suggests that SERPINE1 may reflect the progression of atherosclerosis. In a multivariate analysis, SERPINE1 antibody level was an independent predictor of aCI. Thus, the serum levels of anti-SERPINE1 antibody could potentially serve as a biomarker of atherothrombotic infarction.