Validation of plasma membrane proteins expressed in invading hepatocellular carcinoma

Abstract

Introduction: The current gold standards and most commonly available tests for hepatocellular carcinomar surveillance are assay for serum α-fetoprotein (AFP) and hepatic ultrasonography. Although widely used, AFP level has limited sensitivity and specificity for HCC. Newer methods such as biomarkers or radiological assays for early detection of HCC are urgently needed. This study identified and validated the potential membrane protein related to invading HCC, which may be of interest for discovering a novel potential membrane protein contributing to human HCC. Objective: To identify and validate plasma membrane proteins expressed in invading HCC Methods: Cell surface proteins of invading HepG2 were isolated and separated by SDSPAGE. Protein bands were cut to be analyzed by mass spectrometry. Analysis by mass spectrometry of proteins was checked by RT-PCR and real time PCR, Western blot and immunolocalization in cell line, and validated in various grades of tumor tissues by immunohistochemistry. Correlations of these finding were investigated to gain insights into potential candidate proteins contributing to invasion and metastasis in human HCC. Results: Protein spot named P2 and P3 were identified by mass spectrometry and validated by real time PCR, western blot and immunolocalization and showed in various grades of HCC tissues. Conclusion: 2 and P3 are membrane proteins expressed in invading HCC cell line and HCC tissues that might be potential proteins contributing to invasion and metastasis in human HCC.