Figure 4 Survival curves in different groups of CD133 protein immunostaining. Note: P = 0.000 by Log rank analysis. Table 4 Survival analysis on CD133 protein expression and clinicopathological parameters by Cox model (n = 99 cases) Parameter Selleckchem LDK378 B SE Wald df Sig. Exp(B) 95.0%CI for Exp(B) Gender 0.021 0.009 0.623 1 0.159 1.135 0.315~1.872 Age(year) 0.010 0.013 0.554 1 0.457 1.010 0.991~1.681 Tumor diameter (cm) -0.076 0.070 1.186 1 0.276 0.927 0.872~1.561 Invasion depth

0.288 0.343 0.703 1 0.402 1.334 0.318~6.105 Histological grade 0.001 0.182 0.000 1 0.994 1.001 1.169~4.669 Lymph node metastasis 0.867 0.361 0.035 1 0.042 1.978 1.987~10.238 TNM stage 0.739 0.479 0.249 1 0.046 2.187 1.889~;15.312 Lymphatic vessel infiltration 0.871 0.592 2.168 1 0.141 2.390 0.987~6.558 Vascular infiltration 0.218 0.560 0.152 1 0.697 1.244 2.377~9.912 CD133

protein expression 0.894 0.449 3.966 1 0.046 2.445 2.118~16.381 Discussion CD133/prominin-1, a pentaspan transmembrane glycoprotein, has been initially described as a surface antigen specially to human hematopoietic GW-572016 price stem cells [16] and CSCs with CD 133 positivity have been implicated in tumor progress as identified in tumor growth of pancreatic [11] and colon cancers [4]. AC133, i.e. CD133, polypeptide has a predicted size of 97 kD and contains five-transmembrane (5-TM) domains with an extracellular N-terminus and a cytoplasmic C-terminus. Whereas the expression of tetraspan (4-TM) and 7-TM molecules is well documented on mature and Alanine-glyoxylate transaminase immature hematopoietic cells and leukocytes, this 5-TM type of structure containing two large (255-amino acid [aa] and 290-aa) extracellular loops is unique and does not share sequence homology with any known multi-TM family members [16]. Nowadays, CD133 presentation was found in many solid tumors such as brain tumor [4, 7], prostate [8], pancreatic [11], hepatocellular [12] and colon cancers [5, 6], but the specific role of these CSCs in tumor biology, including metastasis and recurrence, is still uncertain, especially in human GC. Although there are different

phenotypes in different kinds of CSCs, the higher expression of CD133 as same phenotypes has been identified in CSCs, especially in solid tumors derived from epithelium cells of gastrointestinal organs [5–7, 12, 17]. O’Brien and his team [4] identified CD133 positive cells shared the characteristics of human colon cancer-initiating cells, in which CD133 positive cells were able to initiate tumor growth in minor quantity of the cells Moreover, CSCs with CD133 positivity possessed strong carcinogenesis, cloning ability and proliferating capacity as demonstrated in many experiments [4–8, 11, 12, 17], and were resistant to anti-cancer therapy [10, 18]. Hence, the metastasis and recurrence of cancer as one of main factors inflecting on the prognosis has still been hard to be overcome thoroughly until now.