Identification of TRAK1 (Trafficking protein, kinesin-binding 1) as MGb2-Ag: a novel cancer biomarker.
The present study aimed to describe the characterization of an antibody MGb2 that reacts with an epitope on gastric cancer cells, and identification of MGb2 antigen (MGb2-Ag). Immunostaining revealed its distribution in human tissues and demonstrated that the positive rate of MGb2-Ag was 81.48% in gastric cancer, 100% in gastric signet-ring cell carcinoma and mucinous adenocarcinoma, 13.16% in precancerous conditions, and 0% in chronic superficial gastritis. Using Western blotting, immunoprecipitation and MALDI-TOF MS (matrix assisted laser desorption/ionization time-of-flight mass spectrometry), MGb2-Ag was identified as TRAK1 (Trafficking protein, kinesin-binding 1), a new molecular gained limited recognition. Both MGb2 and commercial anti-TRAK1 Ab recognized prokaryotic expressed TRAK1. Immunostaining characteristics of TRAK1 were identical with MGb2-Ag in continuous sections of paraffin-embedded tissues of gastric tissues. This is the first report that TRAK1/MGb2-Ag is a promising diagnostic marker for gastric cancer and may help to detect signet-ring cell carcinoma and mucinous adenocarcinoma.
Zhang
Faming
F
State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an 710032, China.
Ren
Gui
G
Lu
Yuanyuan
Y
Jin
Bin
B
Wang
Jun
J
Chen
Xiong
X
Liu
Zhenxiong
Z
Li
Kai
K
Nie
Yongzhan
Y
Wang
Xin
X
Fan
Daiming
D
D033942:Adaptor Proteins, Vesicular Transport / Q000378:metabolism*; D000906:Antibodies / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D008297:Male; D008875:Middle Aged; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology
D033942:Adaptor Proteins, Vesicular Transport; D000906:Antibodies; D014408:Biomarkers, Tumor; C531552:TRAK1 protein, human