title: Characterization of cancer stem cells from different grades of human colorectal cancer.
abstract: Colorectal cancer (CRC) is one of the most common solid tumors worldwide. Recent evidence suggests that a population of cancer cells, called cancer stem cells (CSCs), is responsible for tumor heterogeneity, invasion, metastasis, therapeutic resistance, and recurrence of CRC. The isolation and characterization of CSCs using cell surface markers have been reported previously with varying results. In this study, we investigated a panel of four putative CSC markers, CD44, CD24, CD166, and EpCAM, to define CRC-CSC. Paraffin embedded tissue samples from different grades of primary, untreated CRC were analyzed for the expression of four CSC markers CD44, CD326, CD24, and CD166, using immunohistochemistry. Flow cytometric analysis of CRC-CSC from HT29 (low grade) and HCT116 (high grade) human colorectal cancer cell lines was done. Marker-based isolation of CSC and non-CSC-bulk-tumor cells from HT29 was done using FACS, and tumor sphere assay was performed. There was a statistically significant difference (p < 0.05) in the expression of CD44, CD326, and CD166 between cases and controls. A novel cutoff distribution of CD44 and CD166 was suggested to help for better immunohistochemical analysis of CRC. Higher prevalence of CSC was seen in high-grade CRC as compared to low-grade CRC. Sorted and cultured CD44 + CD166+ cells formed tumor spheres, suggesting that these cells, having properties of self renewal and anchorage independent proliferation, were in fact CSC. Hence, CD44 and CD166 may serve as good CRC-CSC markers when used together with novel cutoff immunohistochemistry (IHC) expression levels.
authors: Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, 110029, India.
authors: J
authors: J
authors: Manhas
authors: Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, 110029, India.
authors: A
authors: A
authors: Bhattacharya
authors: Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, 110029, India.
authors: S K
authors: SK
authors: Agrawal
authors: Department of Pathology, All India Institute of Medical Sciences, New Delhi, 110029, India.
authors: B
authors: B
authors: Gupta
authors: Department of Pathology, All India Institute of Medical Sciences, New Delhi, 110029, India.
authors: P
authors: P
authors: Das
authors: Department of Surgical Oncology, All India Institute of Medical Sciences, New Delhi, 110029, India.
authors: S V S
authors: SV
authors: Deo
authors: Department of Gastrointestinal Surgery, All India Institute of Medical Sciences, New Delhi, 110029, India.
authors: S
authors: S
authors: Pal
authors: Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, 110029, India. sudipsen99@rediffmail.com.
authors: S
authors: S
authors: Sen
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000556:secondary*; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D051927:CD24 Antigen / Q000378:metabolism; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology*; D000071858:Epithelial Cell Adhesion Molecule / Q000378:metabolism; D005260:Female; D005326:Fetal Proteins / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D007124:Immunoenzyme Techniques; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology*; D011379:Prognosis; D014407:Tumor Cells, Cultured; D020410:Activated-Leukocyte Cell Adhesion Molecule
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor; D051927:CD24 Antigen; D015816:Cell Adhesion Molecules, Neuronal; D000071858:Epithelial Cell Adhesion Molecule; D005326:Fetal Proteins; D018960:Hyaluronan Receptors; C105613:ALCAM protein, human; D020410:Activated-Leukocyte Cell Adhesion Molecule; C497889:CD24 protein, human; C497483:CD44 protein, human
keywords: CD166; CD44; Cancer stem cells; Colorectal cancer