Tumor-infiltrating regulatory T cells are positively correlated with angiogenic status in renal cell carcinoma.

BACKGROUND: Immune cells within a tumor microenvironment have shown modulatory effects on tumor angiogenic activity. Renal cell carcinoma (RCC) is a hypervascular tumor that reportedly increases the frequency of regulatory T cells (Tregs) in tumor tissues. This study investigated the correlation between Tregs infiltration and angiogenic status in RCC. METHODS: Thirty-six patients with RCC were enrolled in the present study, and twenty age-matched healthy donors were included as the control. Tregs were defined as CD4(+)CD25(high)CD127(low/-) T cells. The frequency of Tregs in peripheral blood and tumor infiltrating lymphocytes (TILs) were determined by flow cytometry. The expression of vascular endothelial growth factor (VEGF) in surgical resection specimens were measured with a commercial enzyme-linked immunosorbent assay (ELISA) kit. Microvessel density (MVD) was calculated on slides stained with CD34 antibody. Spearman's rank correlation was performed to evaluate the correlation between the frequencies of Tregs in TILs and VEGF values, as well as between frequencies of Tregs and MVD determinations. RESULTS: Compared to healthy controls, the frequency of peripheral blood Tregs was significantly increased in patients with RCC (P < 0.05). The percentage of tumor-infiltrating Tregs was higher than that of peripheral blood Tregs in patients with RCC (P < 0.01). In addition, the frequency of tumor-infiltrating Tregs was shown to significantly correlate with the pathological stage (P < 0.05) and nuclear grade (P < 0.01). Importantly, a significant positive correlation was observed between the frequency of tumor-infiltrating Tregs and VEGF protein expression (r = 0.51, P < 0.05), as well as between frequencies of Tregs and MVD score (r = 0.39, P < 0.05). CONCLUSIONS: These observations suggest that the high pro-angiogenic status of RCC may be associated with the accumulation of Tregs in the local microenvironment. Angiogenesis networks may be connected with immune tolerance units and cooperate with each other to facilitate tumor growth and progression.

[An analysis for the phenotype and genotype of autosomal dominant polycystic kidney disease from two Chinese families].

OBJECTIVE: To scan for mutations of polycystic kidney disease 1 gene (PKD1) in Chinese population in order to find some features about Chinese patients and a better approach to detect mutations. METHODS: Twenty-five PKD-affected individuals from twenty-one unrelated genealogies and sixteen controls participated in the study. Thirty-five blood samples and six tissues were obtained after receiving informed consent and were in accordance with institutional ethical guidelines. Genomic DNA was isolated from peripheral blood using standard procedures. PCR amplification of genomic DNA was performed to generate the aimed fragments. Amplified fragments were analyzed by denaturing gradient gel electrophoresis (DGGE). A GC clamp was attached to the 5' primer. After that, the abnormal fragments were sequenced on freshly amplified specific PCR products with the dideoxynucleotide chain termination method. Sequencing was performed for all samples to evaluate DGGE. RESULTS: Aimed fragments of exons 44 and 45 were amplified. DGGE detected eleven abnormal PCR fragments. Two novel mutations were identified by sequencing, included one nonsense mutation (C12217T) and one frameshift (12431delCT). In addition, one polymorphism (A50747C) was identified. The mutation detection rate is 8% in our study. CONCLUSION: Two novel pathogenic mutations were detected, including one nonsense mutation (C12217T) and one frameshift (12431delCT).