1A-O1-1500 PDF
大腸癌組織膜タンパク質のプロテオーム解析によるバイオマーカー探索とSRM/MRM法を用いたその検証
Recent advances in quantitative proteomic technology have enabled the validation of biomarkers on a large scale. Here, we performed quantitative proteomic analysis of membrane fractions from colorectal cancer tissue for biomarker discovery and extensively validated biomarker candidate proteins. A total of 5287 of 5566 identified proteins were annotated by GO cellular components analysis and 3087 were predicted to be membrane proteins. Also, 1567 proteins were predicted to have a transmembrane domain by TMHMM algorithm. Differences were observed in the expression of 159 membrane proteins and 55 extracellular proteins between polyps and cancer without metastasis, while the expression of 32 membrane proteins and 17 extracellular proteins differed between cancer with and without metastasis. A total of 105 of these biomarker candidates were quantitated using selected (or multiple) reaction monitoring (SRM/MRM) with stable synthetic isotope-labeled peptides as an internal control. The results obtained revealed differences in the expression of 69 of these proteins, and this was subsequently verified in an independent set of patient samples. Some of the results were also confirmed by Western blotting and immunostaining. These results suggested that our method for biomarker discovery and subsequent validation using SRM/MRM will contribute to identify useful biomarkers for cancer.