Identification of transgelin as a potential novel biomarker for gastric adenocarcinoma based on proteomics technology.
OBJECTIVE
To find a biomarker for gastric adenocarcinomas (GA).


METHODS
Ten protein expression profiles of GA and paired non-neoplastic mucosa tissues were analyzed by two-dimensional gel electrophoresis. Forty-two protein spots that were differentially expressed by twofold or greater between cancer and normal mucosa tissue were excised and identified by MALDI-TOF/TOF MS. One of the over-expressed proteins identified in GA was transgelin, which was chosen for further verification by immunohistochemistry and western blotting.


RESULTS
Forty-two distinct proteins that were differentially expressed at least twofold between the tissues were identified. Expression of 29 of these proteins was decreased (ratio >or= 2, P < 0.01), including adenosine deaminase; and 13 proteins displayed over-expression in cancer tissue (ratio >or= 2, P < 0.01), including transgelin. The results of immunohistochemistry confirmed that transgelin was indeed over-expressed in 22 cases of GA (22/41, 53.66%), with strong cytoplasmic staining in cancer cells of positive samples, this was absent in most paired non-neoplastic mucosa cells or gastric ulcer tissues (n = 20). Transgelin was found over-expressed in 21 samples of cancer tissue (21/41, 51.22%) when detected by western blot.


CONCLUSIONS
This work demonstrates that differentially expressed proteins can be identified by proteomics technology combined with immunohistochemistry and western blot analyses. We have identified one such protein, transgelin, as a novel biomarker for GA.
Huang
Qiaojia
Q
Key Laboratory of Infection and Oncology, Research Center of Molecular Medicine, Fujian Medical University, 88 Jiaotong Road, Fuzhou, 350004, People's Republic of China.
Huang
Qingling
Q
Chen
Wannan
W
Wang
Lin
L
Lin
Wansong
W
Lin
Jianyin
J
Lin
Xu
X
D000230:Adenocarcinoma / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007525:Isoelectric Focusing; D008297:Male; D008840:Microfilament Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008875:Middle Aged; D009124:Muscle Proteins / Q000302:isolation & purification / Q000378:metabolism*; D009367:Neoplasm Staging; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000473:pathology
D014408:Biomarkers, Tumor; D008840:Microfilament Proteins; D009124:Muscle Proteins; C051615:transgelin