Review : The Biology of Cancer Stem Cells and Its Clinical Implication in Hepatocellular Carcinoma = Review : The Biology of Cancer Stem Cells and Its Clinical Implication in Hepatocellular Carcinoma

다국어 초록 (Multilingual Abstract)

Hepatocellular carcinoma (HCC) is a highly malignant tumor with limited treatment options in its advanced state. The molecular mechanisms underlying HCC remain unclear because of the complexity of its multi-step development process. Cancer stem cells (CSCs) are defi ned as a small population of cells within a tumor that possess the capability for selfrenewal and the generation of heterogeneous lineages of cancer cells. To date, there have been two theories concerning the mechanism of carcinogenesis, i.e., the stochastic (clonal evolution) model and the hierarchical (cancer stem cell-driven) model. The concept of the CSC has been established over the past decade, and the roles of CSCs in the carcinogenic processes of various cancers, including HCC, have been emphasized. Previous experimental and clinical evidence indicated the existence of liver CSCs; however, the potential mechanistic links between liver CSCs and the development of HCC in humans are not fully understood. Although defi nitive cell surface markers for liver CSCs have not yet been found, several putative markers have been identifi ed, which allow the prospective isolation of CSCs from HCC. The identifi cation and characterization of CSCs in HCC is essential for a better understanding of tumor initiation or progression in relation to signaling pathways. These markers could be used along with clinical parameters for the prediction of chemoresistance, radioresistance, metastasis and survival and may represent potential targets for the development of new molecular therapies against HCC. This review describes the current evidence for the existence and function of liver CSCs and discuss the clinical implications of CSCs in patients demonstrating resistance to conventional anticancer therapies, as well as clinical outcomes. Such data may provide a future perspective for targeted therapy in HCC. (Gut Liver 2012;6:29-40)