Objective To study the expression of CD133 mRNA in peripheral blood mononuclear cells （PBMCs） of patients with gastric adenocarcinoma （GC） before operation or after operation and its clinical significance. To learn the relationship of CD133 expressions in PBMCs to primary lesion of GC. Methods Fifty patients with GC，10 patients with gastric ulcer （GU）， and 10 healthy volunteers were registered in this research. Expressions of CD133 mRNA in PBMCs and in primary lesion of GC by semi-quantitative RT-PCR and expression of CD133 protein in primary lesion of GC by immunohistochemical staining were detected. Correlations of CD133 mRNA expression with clinicopathologic parameters and postoperative survival rate were analyzed. Relation between CD133 mRNA level and CD133 protein expression or lymphatic metastasis were assessed too. Results The brightness scale value （ABSV） of CD133 mRNA in PBMCs of the patients with GC before operation （0.270±0.163） was higher than that in the healthy volunteers （0.029±0.060） or in the patients with GU （0.059±0.099） （P=0.000）. The ABSV of CD133 mRNA in the PBMCs of patients with GC before operation was related to poor cell differentiation （P=0.002）， lymph vessel invasion （P=0.028），deeper tumor invasion （P=0.041），later lymph node metastasis stage （P=0.010），later TNM stage （P=0.006），and positive expression of CD133 protein in the primary lesion （P=0.011）. Relative analysis revealed that the ABSV of CD133 mRNA in the PBMCs of patients with GC before operation was related positively to metastatic lymphatic nodes ratio （rs=0.422，P=0.002），metastatic lymph node number （rs=0.398，P=0.004），and ABSV of CD133 mRNA in the primary lesion of GC （rs=0.337，P=0.017）. The ABSV of CD133 mRNA in the PBMCs of patients with GC after operation obtained from blood sample at 1 week after curative resection was higher than that in the patients before operation （P=0.021）. Patients suffered from deeper invasion inclined to have a higher ABSV of CD133 mRNA after surgery （P=0.039）. Higher expression of CD133 mRNA in patients after operation demonstrated a much poorer survival rate （P=0.013）. Conclusions Higher expressive level of CD133 mRNA in GC before operation is associated to poor cell differentiation，lymph vessel invasion，deeper invasion，higher lymph node metastasis，later TNM stage，and positive expression of CD133 protein. It is also related positively to metastatic lymphatic nodes ratio，metastatic lymph node number，and ABSV of CD133 mRNA in primary lesion of GC. The level of CD133 mRNA in PBMCs of patients with GC is higher after operation as compared with before operation，which demonstrates deeper invasion and poorer survival.
ObjectiveTo investigate the expressions of contactin-1 (CNTN-1), vascular endothelial growth factor-C (VEGF-C), and its receptor VEGFR-3 (Flt-4) in primary gastric cancer and to explore the relevance among them and their correlation with clinicopathologic features of gastric cancer. MethodsThe VEGF-C, VEGFR-3, and CNTN-1 protein expressions of tumor tissues and normal gastric mucosa tissues in 68 patients with primary gastric cancer were analyzed by immunohistochemistry. The Flt-4-positive vessel density (FVD) and lymphatic vessel density (LVD) were also analyzed by VEGFR-3positive and D2-40-positive staining, respectively. ResultsThe positivity rate of VEGF-C, VEGFR-3, and CNTN-1 protein expression in the primary tumor was 57.4% (39/68), 60.3% (41/68), and 55.9% (38/68), respectively, which was significantly higher than that in the normal gastric mucosa tissues 〔20.6% (14/68), 23.5% (16/68), and 16.2% (11/68)〕， P=0.000. The expressions of VEGF-C, VEGFR-3, and CNTN-1 protein were significantly correlated with TNM stage, lymphatic vessel invasion, and lymph node metastasis (Plt;0.05). The expression of CNTN-1 protein was significantly correlated with VEGF-C (r=0.372, P=0.002) and VEGFR-3 protein expression (r=0.308, P=0.011). In tumor tissues of sixtyeight patients the FVD was (10.41±9.38)/HP, which was significantly lower than LVD 〔(18.19±7.44)/HP〕, P=0.000. Elevated FVD and LVD was significantly found in patients with tumor characterized by later TNM stage, severer lymphatic vessel invasion, and severer lymph node metastasis (Plt;0.05). The FVD of tumor was significantly correlated with VEGF-C (P=0.029) and CNTN-1 protein expression (P=0.003). The LVD of tumor was not significantly correlated with CNTN-1 (P=0.727), VEGF-C (P=0.173), and VEGFR-3 protein expression (P=0.924). The patients with positive expression of VEGF-C, VEGFR-3, and CNTN-1 protein showed poorer prognosis (Plt;0.05). ConclusionsElevated expression of CNTN-1 protein is observed in primary gastric cancer and correlated with VEGF-C and VEGFR-3 protein expression, indicating that combined detection has great value in prediction of invasive potential and prognosis. VEGF-C-mediated CNTN-1 overexpression may promote lymphatic invasion via lymphangiogenesis pathway in patients with gastric cancer.