Side populations of gastrointestinal cancers are not enriched in stem cells.

摘要: The side population (SP) phenotype, defined as the reserpine-blockable ability to efflux nucleic acid dye Hoechst 33342, has been claimed be enriched for stem cells in several human normal tissues, cancers and cell lines, thus may useful identification isolation of cancer cells. We demonstrated presence SP fractions all seven tested gastrointestinal lines. Four lines were selected (HT29, HGT101, Caco2 HRA19a1.1) detailed phenotypic behavioural analysis with respect characteristics. Cell surface marker showed that, contrary non-SP cells, SPs entirely lack expression CD34. This difference, however, disappeared when cultured, rendering both populations CD34-positive. Expression other putative markers (CD133, CD44, Hes-1, beta-catenin, Musashi-1, Oct-4 CD117) was identical on non-SPs before after culturing. Sorted similarly clonogenic vitro, tumourigenic vivo, displayed similar multipotential differentiation potential vitro vivo. Additionally, culturing cytometrically-sorted that are interconvertible, each giving rise other. ABCG2 Mdr-1, two membrane transporter proteins have suggested responsible drug-effluxing capacities including indicating there additional factors effluxing property Here, we show fractions, albeit phenotypically distinct populations, do not differ cell-like number or behaviour. conclude concept phenotype a universal does apply These findings stand contrast observations made many tissues harbour important implications future search intestinal markers.