Anti‐FIRΔexon2 autoantibody as a novel indicator for better overall survival in gastric cancer

Abstract

There is no clinically available biomarker for efficiently indicating the overall survival or therapy response of gastric cancer (GC). The autoantibodies (Abs) in the sera of anti‐far‐upstream element‐binding protein‐interacting repressor‐lacking exon2 (FIRΔexon2), anti‐sorting nexin 15, and anti‐spermatogenesis and oogenesis–specific basic helix–loop–helix 1 were markedly higher in GC patients than in healthy donors (HDs). These Abs were identified by large‐scale serological identification of antigens by recombinant cDNA expression cloning screenings and their expression levels were evaluated by amplified luminescence proximity homogeneous assay. In particular, compared with age‐matched HDs, the level of anti‐FIRΔexon2 Abs in GC patients was significantly higher (P < .001). The Spearman's rank correlation analysis between anti‐FIRΔexon2 Abs and clinically available tumor markers such as carcinoembryonic antigen (CEA) was statistically insignificant, indicating that FIRΔexon2 Abs is an independent biomarker. We performed receiver‐operating curve analysis to evaluate the anti‐FIRΔexon2 Ab as a candidate biomarker with CEA and carbohydrate antigen 19‐9 (CA19‐9). The overall survival of GC patients with high anti‐FIRΔexon2 Abs titer was significantly favorable (P = .04) than that of GC patients who were below detection level of anti‐FIRΔexon2 Abs. However, clinical stages were not apparently correlated with the levels of anti‐FIRΔexon2 Ab, CEA, and CA19‐9. In conclusion, anti‐FIRΔexon2 Abs detected in GC patients is a potential biomarker for monitoring a better prognosis. Hence, anti‐FIRΔexon2 Abs is a promising biomarker for indicating better overall survival of gastric cancer patients.

Combinational antibody detection approach increases the clinical validity of colorectal cancer screening

“…In our previous study, a high level of anti‐FIRΔexon2 Abs in the sera of patients with GC indicated better overall survival (OS) 45 . In contrast, in patients with CRC was not significant (Figure S2).…”

“…In our previous study, a high level of anti‐FIRΔexon2 Abs in the sera of patients with GC indicated better overall survival (OS). 45 In contrast, in patients with CRC was not significant (Figure S2 ). The fact that CEA and CA19‐9 negative patients had better survival rates suggests the reliability of this data analysis.…”

Serum Anti-BRAT1 is a Common Molecular Biomarker for Gastrointestinal Cancers and Atherosclerosis

“…Serological antigen identification by cDNA expression cloning (SEREX) is a liquid biopsy method and an effective technique for screening antigen and antibody markers ( 19 , 20 ). SEREX screens antigens related to tumors and autoimmune diseases including GI cancers [EC ( 21 , 22 ), GC ( 23 ), LC ( 24 ), and CRC ( 25 ) and PC ( 26 )], multiple sclerosis (MS) ( 27 ), systemic sclerosis (SSc) ( 28 ), systemic lupus erythematosus (SLE) ( 29 ), rheumatoid arthritis (RA) ( 30 ), and others. In earlier studies, we successfully applied SEREX to AS-related diseases and identified antibodies against CPSF2, DIDO1, FOXJ2, MMP1, CBX1, CBX5, and LAMP1 in TIA and CI ( 31 – 33 ).…”