Influence of CD133+expression on patients' survival and resistance of CD133+cells to anti-tumor reagents in gastric cancer

ABSTRACT

Objective: To investigate the influence of CD133+expression on patients' survival and resistance of CD133+cells to anti-tumor agents in gastric cancer (GC). Methods: Influence of CD133 expression on prognosis was analyzed employing sam-ples from patients with GC. GC cell lines were utilized to separate CD133+and CD133?subpopulations by immunomagnetic separation and to analyze the biological features of two subpopulations in vitro and in vivo, especially in resistant to anti-tumor reagents and its apoptotic mechanism. Results: The lower CD133+group showed a significantly better survival compared with the higher CD133+group. The highest content of CD133+subpopulations for KATO-III cells had stronger proliferative ability than CD133?subpopulations. A single CD133+cell was capable of generating new cell colony and the tumorigenicity rate in nude mice was 100% for CD133+ clonal spheres or for CD133+ cells, but 0% for CD133? cells. Furthermore, the higher expression levels of Oct-4, Sox-2, Musashi-1 and ABCG2 in CD133+ clonal spheres were identified compared with CD133+ cells or CD133? cells. Under the treatment of anti-tumor reagents, CD133+ cells had lower suppression rates compared with CD133? cells while lower level of Bcl-2 and higher level of Bax were found in CD133+cells compared with CD133?cells. Conclusions: The patients with lower CD133+expression had a better survival. Enriched CD133+ cells in clonal sphere shared the ability to be self-renewable, proliferative, tumorigenic and resistant to anti-tumor agents as probably regulated by Bcl-2 and Bax.