Hepatocellular carcinoma: from bedside to proteomics

Proteomics approaches for early detection and targeted therapy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer related mortality worldwide. HCC incidences have increased worldwide though more prevalent in Asia and Africa. Hepatitis B virus and hepatitis C virus infections are mostly responsible of increased number of HCC cases. Biomarkers can help early detection and improve treatment regimen in patients as advanced stage is chemo-refractive with limited treatment options. Potential of proteomics in finding new biomarkers for early detection has been explored more recently. Future developments in this area rely on how efficiently we manage vast amount of data generated by these techniques and speed up the clinical trials to improve patient care.

Protein profile of human hepatocarcinoma cell line SMMC-7721: Identification and functional analysis

AIM: To investigate the protein profile of human hepatocarcinoma cell line SMMC-7721, to analyze the specific functions of abundant expressed proteins in the processes of hepatocarcinoma genesis, growth and metastasis, to identify the hepatocarcinoma-specific biomarkers for the early prediction in diagnosis, and to explore the new drug targets for liver cancer therapy.

METHODS: Total proteins from human hepatocarcinoma cell line SMMC-7721 were separated by two-dimensional electrophoresis (2DE). The silver-stained gel was analyzed by 2DE software Image Master 2D Elite. Interesting protein spots were identified by peptide mass fingerprinting based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and database searching.

RESULTS: We obtained protein profile of human hepatocarcinoma cell line SMMC-7721. Among the twenty-one successfully identified proteins, mitofilin, endoplasmic reticulum protein ERp29, ubiquinol-cytochrome C reductase complex core protein I, peroxisomal enoyl CoA hydratase, peroxiredoxin-4 and probable 3-oxoacid CoA transferase 1 precursor were the six novel proteins identified in human hepatocarcinoma cells or tissues. Specific functions of the identified heat-shock proteins were analyzed in detail, and the results suggested that these proteins might promote tumorigenesis via inhibiting cell death induced by several cancer-related stresses or via inhibiting apoptosis at multiple points in the apoptotic signal pathway. Other identified chaperones and cancer-related proteins were also analyzed.

CONCLUSION: Based on the protein profile of SMMC-7721 cells, functional analysis suggests that the identified chaperones and cancer-related proteins have their own pathways to contribute to the tumorigenesis, tumor growth and metastasis of liver cancer. Furthermore, proteomic analysis is indicated to be feasible in the cancer study.