However, the process of cancer initiation, find more metastasis and recurrence is sequential and selective, and consists of a series of independent steps with interlinks [3–6]. Reportedly, CD133 expressing cells in glioblstoma and colorectal cancers include, BMS202 in vitro but are apparently not limited to, the small subpopulation of tumor cells

termed as cancer stem cells (CSCs) which mediate tumor initiation, metastasis and recurrence [4–6], and possess the unique self-renewal properties, the multiple differentiating potential, the proliferating aptitude and the carcinogenesis [5, 7, 8]. In addition to being considered as the tumor initiating cell population, CSCs have also been demonstrated to resistance to chemotherapy and radiotherapy implying that they are responsible for tumor recurrence [9, 10]. At the same time, CD133 has been considered as a CSCs marker in many kinds of tumors such as colorectal [5, 6], brain [4, 7], prostate [8], pancreatic [11] and gastric cancers [12]. One of the aims in this study was to investigate the expression

levels of CD133 see more protein and CD133 mRNA in primary lesion of gastric adenocarcinoma (GC) and to compare these expressive levels with clinicopathological characteristics and survival time after curative resection. Additionally, we explored the relation of CD133 mRNA expression level with lymphatic vessel infiltration, lymph node metastasis and metastatic lymph node ratio [13] which factors reflected the status of lymphatic metastasis demonstrated wildly as one of the main risk factors for the prognosis. At the same time, immunostaining for Ki-67, a kind of cellule nucleus protein, and its labeling index

(LI) were applied to assess the proliferating ability of tumor cells with higher or lower CD133 mRNA level and the relation of this proliferating ability of tumor cells sharing higher or lower CD133 mRNA level were evaluated. Methods Patients A total of 99 patients who underwent radical gastrectomy (D2 or D3; R0 or R1) for primary GC at our hospital from July 2004 to July 2009 were registered Abiraterone for immunohistochemical staining in this study. The median age of the patients was 62.0 years old (range 29~83 years old) in this group of patients. Among them, a total of 31 patients from May 2008 to July 2009 were also assessed by semi-quantitative RT-PCR for detecting CD133 mRNA in primary lesion and in noncancerous gastric tissue (NCGT), which was identified by pathological observation, at > 5 cm distance adjacent to primary lesion, and by immunohistochemical staining for Ki-67 expression in tumor cells. In this group of patients, the median age of the patients was 64.0 years old (range 34~83 years old). None of them accepted any preoperative chemotherapy or radiotherapy. All of the cases received postoperative adjuvant chemotherapy. The diameter of tumors was ranged from 1 to 10 cm; median 5.0 cm.