The AC133 epitope, but not the CD133 protein, is lost upon cancer stem cell differentiation.
Abstract Colon cancer stem cells (CSC) can be identified with AC133, an antibody that detects an epitope on CD133. However, recent evidence suggests that expression of CD133 is not restricted to CSCs, but is also expressed on differentiated tumor cells. Intriguingly, we observed that detection of the AC133 epitope on the cell surface decreased upon differentiation of CSC in a manner that correlated with loss of clonogenicity. However, this event did not coincide with a change in CD133 promoter activity, mRNA, splice variant, protein expression, or even cell surface expression of CD133. In contrast, we noted that with CSC differentiation, a change occured in CD133 glycosylation. Thus, AC133 …
Therapeutic implications of Cancer Initiating Cells.
Background: Until few years ago, all neoplastic cells within a tumour were suggested to have tumorigenic capacity, but recent evidences hint to the possibility that such feature is confined to a subset of Cancer Initiating Cells (CICs), also called Cancer Stem Cells (CSCs). These cells are the reservoir of the heterogeneous populations of differentiated cancer cells constituting the tumour bulk. Mechanisms shared with somatic stem cells, such as quiescence, self-renewal ability, asymmetric division and multidrug resistance, allow to these cells to drive tumour growth and to evade conventional therapy. Objective: Here, we give a brief overview on the origin of CICs, the mechanisms involved i…
Bone morphogenetic protein 4 induces differentiation of colorectal cancer stem cells and increases their response to chemotherapy in mice.
BACKGROUND & AIMS: The limited clinical response observed in many patients with colorectal cancer may be related to the presence of chemoresistant colorectal can- cer stem cells (CRC-SCs). Bone morphogenetic protein 4 (BMP4) promotes the differentiation of normal colonic stem cells. We investigated whether BMP4 might be used to induce differentiation of CRC-SCs and for therapeutic purposes. METHODS: CRC-SCs were isolated from 25 tumor samples based on expression of CD133 or using a selection culture medium. BMP4 expression and activity on CRC-SCs were evaluated in vitro; progeny of the stem cells were evaluated by immunofluorescence, immuno- blot, and flow cytometry analyses. The potential …
Aurora-A Is Essential for the Tumorigenic Capacity and Chemoresistance of Colorectal Cancer Stem Cells
Abstract Colorectal cancer stem cells (CR-CSC) are responsible for the generation and maintenance of intestinal tumors and are highly resistant to conventional chemotherapeutic agents. Aurora-A, a serine-threonine kinase involved in mitosis regulation, plays multiple key functions in tumor initiation and progression. We found that Aurora-A is overexpressed in primary colorectal tumor cells, in the CR-CSC fraction, and in stem cell–derived differentiated cells, compared with normal colon tissue. Aurora-A expression was functionally linked to centrosome amplification in CR-CSC, as indicated by the decrease in cells with multiple centrosomes that followed Aurora-A silencing. Knockdown of Auror…
IL-4-mediated drug resistance in colon cancer stem cells
Cancer stem cells are defined as cells able to both extensively self-renew and differentiate into progenitors. Cancer stem cells are thus likely to be responsible for maintaining or spreading a cancer, and may be the most relevant targets for cancer therapy. The CD133 glycoprotein was recently described as a reliable cancer stem-like cell marker in colon carcinoma. CD133+ cells are both necessary and sufficient to initiate tumour growth in animal models. The CD133+ cell population and spheroid cultures contain cells expressing the stem cell marker Musashi-1 which is involved in maintenance of stem cell fate in several tissues and importantly, this expression is maintained in stem-like cells…