Conclusions
Our in vitro and in vivo experiments demonstrated that CD133(+) ABCG2(+) cells exhibited well-known CSC characteristics; thus when circulating they could be used as a prognostic marker for gastric cancer.
Methods
The present study was designed to recognise circulating CSCs from blood samples of patients with gastric cancer, using CD133 and ABCG2 as potential markers. CD133(-) , CD133(+) ABCG2(-) and CD133(+) ABCG2(+) cells lines were analysed by flow cytometry, immunofluorescence staining, western blotting and real-time PCR. Furthermore, functional assays (clonogenic assay in vitro and tumourigenic assay in vivo) were also performed using these cell lines.
Results
Higher percentages of CD133(+) cells were identified in blood samples from gastric cancer patients compared to normal controls. In addition, we found by using Kaplan-Meier analysis, that numbers of CD133(+) cells correlated with poor prognosis gastric cancer patients. Finally, tumourigenic properties of CD133(+) ABCG2(+) cells were determined in vitro and in vivo. Conclusions: Our in vitro and in vivo experiments demonstrated that CD133(+) ABCG2(+) cells exhibited well-known CSC characteristics; thus when circulating they could be used as a prognostic marker for gastric cancer.