Identification of HSP27 as a potential tumor marker for colorectal cancer by the two-dimensional polyacrylamide gel electrophoresis

• DOI: 10.1007/s11033-009-9903-x
• Publication Date: 2009-10-15T07:29:59Z
• Authors: Weijie Liu; Yanlei Ma; Long Huang; Jiayuan Peng; Peng Zhang; Huizhen Zhang; Jie Chen; Huanlong Qin
• Keywords: Proteomics; 0301 basic medicine; Molecular Sequence Data; HSP27 Heat-Shock Proteins; Immunohistochemistry; Neoplasm Proteins; 3. Good health; 03 medical and health sciences; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Biomarkers, Tumor; Humans; Electrophoresis, Gel, Two-Dimensional; Amino Acid Sequence; Colorectal Neoplasms; Databases, Protein; Heat-Shock Proteins; Molecular Chaperones

The identification of specific biomarkers for colorectal cancer would provide the basis for early diagnosis, prognosis, therapy, as well as clues for understanding the molecular mechanisms governing cancer progression. This study was designed to use comparative proteomics technology to find the differentially expressed proteins between human colorectal carcinoma and the corresponding normal tumor-adjacent colorectal tissues. We have used the highly sensitive two-dimensional gel electrophoresis (2-DE) coupled with matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) for the identification of proteins differentially expressed in tumoral and neighboring normal mucosa. We have detected differences in abundance of 42 proteins with statistical variance of the tumor versus normal spot volume ratio within the 95th confidence level (Student's t-test; P < 0.05). 10 out of 42 analyzed proteins were unambiguously identified by MS coupled with database interrogation as being differentially expressed in colorectal cancer. Of the 10 newly implicated proteins, HSP27 was chosen for detailed analysis. Preliminary studies demonstrated that the differentially expressed proteins found by 2-DE could be confirmed and validated by western blotting and immunohistochemistry analyses in those few cases. The results suggest that HSP27 might be a potential biomarker for early diagnosis, prognosis, monitoring in the therapy of colorectal carcinoma.