DNA alterations in Cd133+ and Cd133- tumour cells enriched from intra-operative human colon tumour biopsies

Abstract

BackgroundTumour stem cells are considered important to promote disease progression, recurrence and treatment resistance following chemotherapy in colon cancer. However, genomic analyses of colorectal cancer have mainly been performed on integrated tumour tissue consisting of several different cell types in addition to differentiated tumour cells. The purpose of the present study was to compare genomic alterations in two cell fractions enriched of CD133+ and CD133−/EpCAM+ cells, respectively, obtained from fresh intraoperative human tumour biopsies.MethodsThe tumour biopsies were fractionated into CD133+ and CD133−/EpCAM+ cells by immunomagnetic separation, confirmed by immunocytochemistry and Q-PCR. DNA were extracted and used for array comparative genome hybridization (aCGH) after whole genome amplification. Frozen tumour tissue biopsies were used for DNA/RNA extraction and Q-PCR analyses to check for DNA alterations detected in the cell fractions.ResultsThe number and size of DNA alterations were equally distributed across the cell fractions; however, large deletions were detected on chromosome 1, 7 and 19 in CD133−/EpCAM+ cells. Deletions were frequent in both cell fractions and a deletion on chromosome 19p was confirmed in 90% of the patients.ConclusionIsolation of enriched cells derived from tumour tissue revealed mainly genomic deletions, which were not observed in tumour tissue DNA analyses. CD133+ cells were genetically heterogeneous among patients without any defined profile compared to CD133−/EpCAM+ cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-017-3206-8) contains supplementary material, which is available to authorized users.

miR‑124 participates in the proliferation and differentiation of brain glioma stem cells through regulating Nogo/NgR expression

“…Then the expression levels of Nogo, and NgR protein were detected and found that with the increase of miR-124 expression level, the expression level of NgR protein decreased, and correlation analysis also revealed that there was a negative correlation between miR-124 and the expression level of Nogo and NgR protein, which suggested that there might be some regulatory relationship between miR-124 and Nogo/NgR pathway. CD133 is recognized as a surface marker of tumor stem cells, which is not expressed on the surface of differentiated tumor cells (16). Therefore, expressing the quantitative proportion of CD133 cells can reflect the differentiation of stem cells to some extent.…”