To investigate the effects of dendritic cells (DCs) transfected with full length wild type p53 and modified by gastric cancer lysates on immune response, the wild type P53 was transducted to DCs with adenovirus, and the DCs were modified by gastric cancer lysates (Lywt-P53DC). The concentration of the surface molecules (B7-1, B7-2, MHC-I , MHC-II) of all DCs was determined by FACS, and the ability of the DCs to induce efficient and specific immunological response in anti-51Cr-labeled target cells studied. BALB/c mice model infected with DCs and Mk28 was established. CTL response in mice immunized with Lywt-p53DC and the effectiveness of Lywt-p53DC in the treatment of tumor-bearing mice was assayed. FACS revealed that the surface molecules of Ly-wt-P53 DC had a high expression: for B7-1 86.70% +/- 0.07%, B7-2 18.77% +/- 0.08%, MHC-I 87.20% +/- 0.05%, MHC-II 56.70%+/-0.07%; The T lymphocytes had a specific CTL lysing ability induced by Lywt-P53DC with the CTL lysis rate being 81%. The immune protective effect of Lywt-p53DC group was more obvious than any other groups (P<0.05). The tumor diameter in Lywt-p53DC group was 3.10+/-0.31 mm, 2.73+/-0.23 mm, 3.70+/-0.07 mm on the day 13, 16 and 19, smaller than DC, wtp53DC and LyDC groups (P<0.05). On the other hand, the growth rate of tumor in Lywt-p53DC group was slower than any other groups (P<0.05). It was suggested that DCs transfected with wild type P53 and modified by gastric cancer lysates had specific CTL killing capability.
Adenoviridae ; genetics ; metabolism ; Animals ; Cell Line, Tumor ; Dendritic Cells ; immunology ; metabolism ; Female ; Genetic Vectors ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; biosynthesis ; genetics ; Stomach Neoplasms ; immunology ; pathology ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics

Although N-myc downstream regulated gene 2 (NDRG2) has been known to be a tumor suppressor gene, the function of this gene has not been elucidated. In the present study, we investigated the expression and function of NDRG2 in human gastric cancer. Among seven gastric cancer and two non-cancer cell lines, only two gastric cancer cell lines, SNU-16 and SNU-620, expressed NDRG2, which was detected in the cytoplasm. Interestingly, NDRG2 was highly expressed in normal gastric tissues, but gastric cancer patients were divided into NDRG2-positive and -negative groups. The survival rate of NDRG2-negative patients was lower than that of NDRG2-positive patients. We confirmed that the loss of NDRG2 expression was a significant and independent prognostic indicator in gastric carcinomas by multivariate analysis. To investigate the role of NDRG2 in gastric cancer cells, we generated a NDRG2-silenced gastric cancer cell line, which stably expresses NDRG2 siRNA. NDRG2-silenced SNU-620 cells exhibited slightly increased proliferation and cisplatin resistance. In addition, inhibition of NDRG2 decreased Fas expression and Fas-mediated cell death. Taken together, these data suggest that inactivation of NDRG2 may elicit resistance against anticancer drug and Fas-mediated cell death. Furthermore, case studies of gastric cancer patients indicate that NDRG2 expression may be involved in tumor progression and overall survival of the patients.
Apoptosis/*physiology ; Cell Line, Tumor ; Down-Regulation ; Fas Ligand Protein/*physiology ; Gene Expression Regulation, Neoplastic ; Humans ; Stomach Neoplasms/metabolism/*mortality/pathology ; Tumor Markers, Biological/*metabolism ; Tumor Suppressor Proteins/biosynthesis/genetics/immunology/*metabolism