Comparative Plasma Membrane-Associated Proteomics of Immortalized Human Hepatocytes

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Lan-Tu Gou, Ai-Ping Tong, Li-Juan Chen, Ming-Hai Tang, Bin Chen, Shu-Fang Liang, Canhua Huang^*, and Yu-Quan Wei^*

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China; fax: +86-28-85164060; E-mail: hcanhua@hotmail.com; yuquawei@hotmail.com

^* To whom correspondence should be addressed.

Received December 3, 2007; Revision received February 27, 2008

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This work was initiated with the purpose of purifying and identifying differentially expressed plasma membrane-associated proteins between human liver cancer cell line HepG2 and normal liver cell line L02. The combined strategy of sucrose density gradient centrifugation and subsequent phase partition was applied to obtain high-purity proteins of plasma membrane. Two-dimensional gel electrophoresis revealed the differential protein profile between the two cell lines. A total of 13 plasma membrane-associated proteins containing 10 up-regulated proteins and three down-regulated proteins in HepG2 cells were successfully identified by MALDI-Q-TOF mass spectrometry; they participate in multiple biological functions such as adhesion, proliferation, apoptosis, and signal transduction. The identified proteins could provide helpful reference in clinical investigations on potential candidates for diagnosis and therapy of liver cancer.

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KEY WORDS: plasma membrane, liver cancer, sucrose density gradient centrifugation, two-dimensional gel electrophoresis, proteomics, MALDI-Q-TOF

DOI: 10.1134/S0006297908110059

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