PDF file - 1414K, Supplemental Figure 2. CD90, CD44 and p75NTR / CD271 expression in matched non-tumor (N) and primary ESCC (T) (n = 33) as detected by real-time qPCR.
ARTICLE ABSTRACTTumor-initiating cells (TIC), also known as cancer stem cells, are regarded widely as a specific subpopulation of cells needed for cancer initiation and progression. TICs have yet to be identified in esophageal tumors that have an increasing incidence in developed countries. Here, we report a CD90+ cell population found in esophageal squamous cell carcinoma (ESCC), which is endowed with stem cell–like properties and high tumorigenic and metastatic potential. mRNA profiling of these cells suggested pathways through which they drive tumor growth and metastasis, with deregulation of an Ets-1/MMP signaling pathway and epithelial–mesenchymal transition figuring prominently. These cells possessed higher self-renewal activity and were sufficient for tumor growth, differentiation, metastasis, and chemotherapeutic resistance. CD90+ TICs were isolated and characterized from ESCC clinical specimens as well as ESCC cell lines. In freshly resected clinical specimens, they represented a rare cell population, the levels of which correlated with strong family histories and lymph node metastasis. Our results prompt further study of this CD90+ population of esophageal TICs as potential therapeutic targets. Cancer Res; 73(7); 2322–32. ©2013 AACR.