Overexpression of the Interferon regulatory factor 4-binding protein in human colorectal cancer and its clinical significance.
BACKGROUND
IFN regulatory factor 4-binding protein (IBP) is a novel type of activator of Rho GTPases. It has been linked with differentiation and apoptosis of lymphocytes, but its function in oncogenesis remains unclear. Here we studied the expression of endogenous IBP in four human colorectal cancer cell lines, normal, adenoma and tumor colorectal tissues.


METHODS
Molecular (Western blot and RT-PCR), and confocal analyses were used to investigate IBP expression in human colorectal cancer cell lines. Matched normal and tumor tissue sections of 63 patients and 15 adenoma tissue sections were analyzed for IBP expression by immunohistochemistry (IHC).


RESULTS
IBP was ubiquitely expressed in human colorectal cancer cell lines. The expression of IBP can be detected at both the mRNA and protein level in SW480, SW620 and HT29 cells. Clinically, IBP were elevated in human colorectal cancer specimens in comparison to normal colorectal tissues. Substantial high expression of IBP was observed in colorectal cancer tissues (67%), whereas corresponding normal tissues and 15 adenoma tissues showed consistently absent immunoreactivity of IBP. Moreover, IBP expression is correlated with the differentiation level of colorectal cancer cells (p<0.05) and clinical stage of patients (p<0.01).


CONCLUSIONS
Our data show, for the first time, a dysregulated expression of IBP in human colorectal cancer, offering new perspectives for its role in cancer development and progression. IBP may be a novel tumor marker and a therapeutic target for colorectal cancer.
Zhang
Zhujun
Z
Department of Clinical Biochemistry, Laboratory Science, Third Military Medical University, Chongqing, PR China.
Wang
Qingliang
Q
Li
Peng
P
Zhou
Yu
Y
Li
Shuhui
S
Yi
Weijing
W
Chen
An
A
Kong
Peiyan
P
Hu
Chuanmin
C
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D002288:Adenocarcinoma, Mucinous / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D000231:Adenocarcinoma, Papillary / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D000236:Adenoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000368:Aged; D000818:Animals; D015153:Blotting, Western; D003106:Colon / Q000378:metabolism / Q000473:pathology; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005455:Fluorescent Antibody Technique; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D012007:Rectum / Q000378:metabolism / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
C479750:DEF6 protein, human; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D009687:Nuclear Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins