Development of IGF signaling antibody arrays for the identification of hepatocellular carcinoma biomarkers.
OBJECTIVE
Our objective was to develop a system to simultaneously and quantitatively measure the expression levels of the insulin-like growth factor (IGF) family proteins in numerous samples and to apply this approach to profile the IGF family proteins levels in cancer and adjacent tissues from patients with hepatocellular carcinoma (HCC).


METHODS
Antibodies against ten IGF family proteins (IGF-1, IGF-1R, IGF-2, IGF-2R, IGFBP-1, IGFBP-2, IGFBP-3, IGFBP-4, IGFBP-6, and Insulin) were immobilized on the surface of a glass slide in an array format to create an IGF signaling antibody array. Tissue lysates prepared from patient's liver cancer tissues and adjacent tissues were then applied to the arrays. The proteins captured by antibodies on the arrays were then incubated with a cocktail of biotinylated detection antibodies and visualized with a fluorescence detection system. By comparison with standard protein amount, the exact protein concentrations in the samples can be determined. The expression levels of the ten IGF family proteins in 25 pairs of HCC and adjacent tissues were quantitatively measured using this novel antibody array technology. The differential expression levels between cancer tissues and adjacent tissues were statistically analyzed.


RESULTS
A novel IGF signaling antibody array was developed which allows the researcher to simultaneously detect ten proteins involved in IGF signal pathway with high sensitivity and specificity. Using this approach, we found that the levels of IGF-2R and IGFBP-2 in HCC tissues were higher than those in adjacent tissues.


CONCLUSIONS
Our IGF signaling antibody array which can detect the expression of ten IGF family members with high sensitivity and specificity will undoubtedly prove a powerful tool for drug and biomarker discovery.
Department of Hepatobiliary Surgery, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
Qi
Q
Zhou
Ying-Qing
YQ
Mao
Wei-Dong
WD
Jiang
Yun-Ru
YR
Chen
Ren-Yu
RY
Huang
Xiang-Bing
XB
Zhou
Ya-Feng
YF
Wang
Zhi
Z
Shi
Zhong-Sheng
ZS
Wang
Ruo-Pan
RP
Huang
D000906:Antibodies / Q000276:immunology*; D055910:Antibodies, Immobilized / Q000276:immunology; D014408:Biomarkers, Tumor / Q000032:analysis / Q000145:classification / Q000276:immunology*; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000276:immunology* / Q000378:metabolism; D016000:Cluster Analysis; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007328:Insulin / Q000032:analysis / Q000276:immunology; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000032:analysis / Q000276:immunology; D018969:Insulin-Like Growth Factor Binding Proteins / Q000032:analysis / Q000276:immunology; D008113:Liver Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D046228:Microarray Analysis / Q000379:methods; D020033:Protein Isoforms / Q000032:analysis / Q000276:immunology; D017526:Receptor, IGF Type 1 / Q000032:analysis / Q000276:immunology; D017527:Receptor, IGF Type 2 / Q000032:analysis / Q000276:immunology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015398:Signal Transduction / Q000276:immunology*; D013002:Somatomedins / Q000032:analysis / Q000276:immunology*
D000906:Antibodies; D055910:Antibodies, Immobilized; D014408:Biomarkers, Tumor; D007328:Insulin; D018971:Insulin-Like Growth Factor Binding Protein 2; D018969:Insulin-Like Growth Factor Binding Proteins; D020033:Protein Isoforms; D017527:Receptor, IGF Type 2; D013002:Somatomedins; D017526:Receptor, IGF Type 1