Evaluation of CD44 and CD133 as cancer stem cell markers for colorectal cancer

Abstract

Colorectal cancer (CRC) is a major cause of cancer-related mortality in the world. Recently, a number of studies have demonstrated that cancer stem cells (CSCs) present in colorectal cancer tissues, are responsible for resistance to conventional therapies. Therefore, effective recognition of CSCs is of great importance. In the present study, to explore the potential characterizations of CSCs by the expression of specific cell surface markers such as CD133 and CD44, we screened six CRC cell lines using western blotting, immunofluorescence and flow cytometry. SW620, one of the six cell lines analyzed, was sorted into four subpopulations by fluorescence activated cell sorting (FACS). The capability of colony formation, proliferation rate, apoptosis, drug resistance, as well as their migratory and invasion potential were detected. The results revealed that the combination of CD44 and CD133 correlates with the features of CSCs in SW620 cells. CD44 positive cells showed more robust colony formation, higher proliferation, less spontaneous apoptosis, a higher resistance to drug-induced cell death, and were enriched after drug treatment. Among CD44 positive SW620 cells, the CD133 negative subpopulation was more migratory and invasive, which means that CD44+CD133− correlates with most of features proposed for CSCs. Overall, the data presented herein showed that CRCs have a wide range of expression for CD44 and CD133; it is unlikely the CSCs can be characterized by any single marker or the same set of markers for all colon cancer cells. For SW620 cells, the CSCs are likely represented by the CD44+CD133− surface marker. This finding of CSC markers represented by one positive and one negative is in line with CSCs in other tumors, such as CD34+CD38− for acute myeloid leukemia; CD44+CD24− for breast and pancreatic tumors. The absence of surface molecule(s) on CSCs will make it even more difficult to track and target this group of minority cells.

Autocrine Secretion of Progastrin Promotes the Survival and Self-Renewal of Colon Cancer Stem–like Cells

“…Progastrin was shown to promote the proliferation of progenitor cells in the mouse colonic epithelium (16) and a link has been suggested between progastrin expression and populations of cells expressing CD133 (17), DCAMKL1 (18), or CD44 (19) in mouse colonic crypts and human cancer cell lines. Yet, expression of these markers is not restricted to CSCs (20)(21)(22)(23), and the functional role of progastrin on CSC self-renewal and tumor-initiating potential has not been documented.…”

Hyaluronic acid–nimesulide conjugates as anticancer drugs against CD44-overexpressing HT-29 colorectal cancer in vitro and in vivo

“…Hence, CD44 represents a potential therapeutic target for the treatment of CRC. [14][15][16] Hyaluronic acid (HA), which is composed of disaccharide repeats of d-glucuronic acid and N-acetyl-d-glucosamine, is a linear polysaccharide that binds specifically to cell surface receptors, such as CD44, RHAMM and ICAM-1, to activate a wide range of intracellular signals and regulate various cellular processes, including morphogenesis, wound healing, inflammation and pathologic conditions. [17][18][19] In addition, with its excellent hydrophilicity, high biocompatibility, nontoxic and nonirritant properties, HA is a favorable natural material for biomedical applications, such as cosmetics, 20 cell therapy, 21 tissue engineering 22 and drug delivery.…”

Anti‑inflammatory drug resistance selects putative cancer stem cells in a cellular model for genetically predisposed colon cancer

“…In this context, it is noteworthy that CD44 + and CD133 + stem cells have been documented in several human colon carcinoma-derived cell lines (31)(32)(33), and positive expression of these markers in colon carcinoma-derived HCT-116 cells have been correlated with the metastatic phenotype (31). In addition, as regards the upregulated expression of CD44 and c-Myc, supportive lines of evidence suggest that these Apc target genes are upregulated in colon cancer stem cells (20)(21)(22)(31)(32)(33). Furthermore, the SUL-R phenotype also raises the possibility that these resistant cells may display altered expression of non-COX targets, such as β-catenin, E-cadherin, mitochondrial apoptotic proteins, cyclin-dependent kinase inhibitor p21 WAF1/CIP1 and peroxisome proliferator-activated receptor-γ (PPAR-γ).…”

“…It is noteworthy that drug-resistant cancer stem cells have been isolated and characterized from colon carcinoma-derived cell culture models (31)(32)(33) and from luminal A and triple-negative breast carcinoma-derived cell culture models (43,44).…”