Gastroenterology Unit, Department of Clinical and Experimental Medicine, University of Naples Federico II, Naples, Italy.
J Cell Physiol. 2012 Jun;227(6):2686-93. doi: 10.1002/jcp.23013.
Emerging evidence suggests that tumors contain and are driven by a cellular component that displays stem cell properties, the so-called cancer stem cells (CSCs). CSCs have been identified in several solid human cancers; however, there are no data about CSCs in primary human gastric cancer (GC). By using CD133 and CD44 cell surface markers we investigated whether primary human GCs contain a cell subset expressing stem-like properties and whether this subpopulation has tumor-initiating properties in xenograft transplantation experiments. We examined tissues from 44 patients who underwent gastrectomy for primary GC. The tumorigenicity of the cells separated by flow cytometry using CD133 and CD44 surface markers was tested by subcutaneous or intraperitoneum injection in NOD/SCID and nude mice. GCs included in the study were intestinal in 34 cases and diffuse in 10 cases. All samples contained surface marker-positive cells: CD133(+) mean percentage 10.6% and CD133(+)/CD44(+) mean percentage 27.7%, irrespective of cancer phenotype or grade of differentiation. Purified CD133(+) and CD133(+)/CD44(+) cells, obtained in sufficient number only in 12 intestinal type GC cases, failed to reproduce cancer in two mice models. However, the unseparated cells produced glandular-like structures in 70% of the mice inoculated. In conclusion, although CD133(+) and CD133(+)/CD44(+) were detectable in human primary GCs, they neither expressed stem-like properties nor exhibited tumor-initiating properties in xenograft transplantation experiments.
新出现的证据表明，肿瘤包含并由具有干细胞特性的细胞成分驱动，即所谓的癌症干细胞（CSC）。已经在几种实体人类癌症中鉴定出 CSC；然而，关于原发性人类胃癌（GC）中的 CSC 尚无数据。通过使用 CD133 和 CD44 细胞表面标志物，我们研究了原发性人类 GC 是否含有表达干细胞样特性的细胞亚群，以及该亚群在异种移植实验中是否具有肿瘤起始特性。我们检查了 44 名接受原发性 GC 胃切除术的患者的组织。使用 CD133 和 CD44 表面标志物通过流式细胞术分离的细胞的致瘤性通过皮下或腹腔注射到 NOD/SCID 和裸鼠中进行测试。纳入研究的 GC 中，34 例为肠型，10 例为弥漫型。所有样本均含有表面标记阳性细胞：CD133(+) 平均百分比为 10.6%，CD133(+)/CD44(+) 平均百分比为 27.7%，与癌症表型或分化程度无关。仅在 12 例肠型 GC 中获得了足够数量的纯化 CD133(+)和 CD133(+)/CD44(+) 细胞，但在两种小鼠模型中均未能重现癌症。然而，未分离的细胞在接种的 70%的小鼠中产生了腺状结构。总之，尽管在人类原发性 GC 中可以检测到 CD133(+)和 CD133(+)/CD44(+)，但它们在异种移植实验中既没有表达干细胞样特性，也没有表现出肿瘤起始特性。
