The molecular regulation of the growth of colorectal cancer (CRC) cells is not completely understood. Here， we report expression of Lgr5， a stem cell marker for the intestine and hair follicle， in some of the CRC cells in the patients. To determine the role of Lgr5-positive cells in the tumorigenesis of CRCs， we prepared an adeno-associated virus (AAV) that carries diphtheria toxin fragment A (DTA) under the control of Lgr5 promoter (AAV-pLgr5-DTA). Transduction of several CRC cell lines with this virus selectively killed Lgr5-positive cells， resulting in significant inhibition of the CRC cell growth in vitro and in vivo. Thus， our data highlight a potential role of Lgr5-positive cells in the tumori... More
The molecular regulation of the growth of colorectal cancer (CRC) cells is not completely understood. Here， we report expression of Lgr5， a stem cell marker for the intestine and hair follicle， in some of the CRC cells in the patients. To determine the role of Lgr5-positive cells in the tumorigenesis of CRCs， we prepared an adeno-associated virus (AAV) that carries diphtheria toxin fragment A (DTA) under the control of Lgr5 promoter (AAV-pLgr5-DTA). Transduction of several CRC cell lines with this virus selectively killed Lgr5-positive cells， resulting in significant inhibition of the CRC cell growth in vitro and in vivo. Thus， our data highlight a potential role of Lgr5-positive cells in the tumorigenesis of CRCs， and suggest that treating these Lgr5-positive cells in CRCs may substantially improve the outcome of CRC therapy.
