GABARAP is overexpressed in colorectal carcinoma and correlates with shortened patient survival.
OBJECTIVE
Gamma-aminobutyric acid type A (GABAA) receptor-associated protein (GABARAP), the mammalian homologue of yeast Atg8, is involved in autophagosome formation during autophagy. The aim of this study is to explore the expression and its prognostic significance in comparison with various clinicopathological predictors of survival.


METHODS
GABARAP protein expression was determined by immunohistochemistry in 103 colorectal cancers. Cytoplasmic immunoreactivity was scored semiquantitatively. The results were analyzed in correlation with various clinicopathological variables, including patient survival. Chi-square test and Kaplan-Meier survival analysis were applied.


RESULTS
The expression of GABARAP was significantly higher in colorectal cancers than that in adjacent matched nontumor tissues (51.5% vs 33.0%, p < 0.01). Increased expression of GABARAP expression in colorectal cancers was significantly correlated with a low grade of differentiation and shortened overall survival (p < 0.05). There were no significant differences between the expression of GABARAP and age, gender, stage, tumor size, location of primary tumor, and lymph node invasion.


CONCLUSIONS
Our data demonstrated that GABARAP is frequently expressed in colorectal cancer. Overexpression of GABARAP is a new independent prognostic marker, which is associated with poor differentiation as well as shortened overall survival.
Miao
Yufeng
Y
Department of Medical Oncology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing 210002, China.
Zhang
Youwei
Y
Chen
Yonglin
Y
Chen
Longbang
L
Wang
Fangyu
F
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051017:Apoptosis Regulatory Proteins; D014408:Biomarkers, Tumor / Q000378:metabolism; D016009:Chi-Square Distribution; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D016019:Survival Analysis
D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D014408:Biomarkers, Tumor; C116741:GABARAP protein, human; D008869:Microtubule-Associated Proteins