In:
Cancer Research, American Association for Cancer Research (AACR), Vol. 68, No. 11 ( 2008-06-01), p. 4287-4295
Abstract:
Adult hepatic progenitor (oval) cells are facultative stem cells in liver, which participate in a range of human liver diseases, including hepatocellular carcinoma (HCC). However, the molecular pathways regulating the expansion and differentiation of these cells are poorly understood. We show that active Wnt/β-catenin signaling occurs preferentially within the oval cell population, and forced expression of constitutively active β-catenin mutant promotes expansion of the oval cell population in the regenerated liver. More importantly, we identify a subpopulation of less differentiated progenitor-like cells in HCC cell lines and primary HCC tissues, which are defined by expression of the hepatic progenitor marker OV6 and endowed with endogenously active Wnt/β-catenin signaling. These OV6+ HCC cells possess a greater ability to form tumor in vivo and show a substantial resistance to standard chemotherapy compared with OV6− tumor cells. The fraction of tumor cells expressing OV6 is enriched after Wnt pathway activation, whereas inhibition of β-catenin signaling leads to a decrease in the proportion of OV6+ cells. In addition, the chemoresistance of OV6+ HCC progenitor-like cells can be reversed by lentivirus-delivered stable expression of microRNA targeting β-catenin. These results highlight the importance of the Wnt/β-catenin pathway in activation and expansion of oval cells in normal rodent models and human HCCs. OV6+ tumor cells may represent the cellular population that confers HCC chemoresistance, and therapies targeted to the Wnt/β-catenin signaling may provide a specific method to disrupt this resistance mechanism to improve overall tumor control with chemotherapy. [Cancer Res 2008;68(11):4287–95]
Type of Medium:
Online Resource
ISSN:
0008-5472
,
1538-7445
DOI:
10.1158/0008-5472.CAN-07-6691
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2008
detail.hit.zdb_id:
2036785-5
detail.hit.zdb_id:
1432-1
detail.hit.zdb_id:
410466-3
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