Inconsistent immunohistochemical expression patterns of four different CD133 antibody clones in glioblastoma

Hermansen, S. K. (Foredragsholder)

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Beskrivelse

The putative tumor stem cell marker CD133 is the marker of choice for identifying brain tumor stem cells in gliomas, but the use of different antibody clones recognizing different epitopes with different glycosylation status, confuses the field. In this study, we sat out to highlight if current discordant CD133 observations could be a result of using different CD133 antibodies for immunohistochemical identification of CD133.
Paraffin embedded sections of glioblastoma, kidney, pancreas and placenta tissue as well as glioblastoma and retinoblastoma cell lines were stained with four different CD133 antibody clones and analyzed using light microscopy. Ten consecutive sections of glioblastomas were analyzed with each of the four CD133 clones using quantitative stereology.
Results revealed presence of CD133+ niches in glioblastomas, often in close relation to blood vessels, using all four antibody clones. The distribution of identified niches did, however, rarely correspond among each antibody clone. Staining of glioblastoma single and niche cells was predominantly cytoplasmatic, which is opposed to the membranous staining observed in epithelial cells in kidney, pancreas and placenta tissues. Quantitative stereology revealed vast dissimilarities regarding fractions of CD 133+ niches and single cells among the CD133 antibody clones. Generally, the fraction of CD133 positivity identified by clone W6B3C1 was significantly higher than CD133 fractions identified by clones AC133, ab19898 and C24B9. Furthermore, clone W6B3C1 was the only clone to stain tumor blood vessels. In conclusion, we report that using different CD133 antibodies for immunohistochemical identification of CD133+ cells on paraffin sections will most likely cause dissimilar results. Thus, direct comparison of CD133 studies using different primary CD133 antibodies should be performed with caution.
Periode29. apr. 2010
BegivenhedstitelÅben forskerdag: null
BegivenhedstypeKonference
PlaceringFredericia, Danmark