A higher circulating concentration of 25-hydroxyvitamin-D decreases the risk of renal cell carcinoma: a case-control study

ABSTRACT Objective: To investigate the relationship between vitamin D status, using circulating 25-hydroxyvitamin D [25 (OH) D], and renal cell carcinoma (RCC) risk in a case-control study, because the association between the two is unclear in China. Materials and Methods: A total of 135 incident RCC cases were matched with 135 controls by age and sex. The blood samples were collected on the first day of hospitalization before surgery to measure plasma 25 (OH) D. Logistic regression analyses were used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) with adjustment for several confounders (e.g. age, gender, smoking and season of blood draw). Furthermore, the association of RCC with 25 (OH) D in units of 10 ng / mL as a continuous variable were also examined. Results: The average plasma 25 (OH) D concentrations in RCC were significantly lower compared with those of the controls (21.5 ± 7.4 ng / mL vs. 24.1 ± 6.6 ng / mL, respectively; P = 0.003). In the adjusted model, inverse associations were observed between circulating 25 (OH) D levels and RCC risk for 25 (OH) D insufficiency (20-30 ng / mL) with OR of 0.50 (95% CI: 0.29-0.88; P = 0.015) and a normal 25 (OH) D level (≥ 30 ng / mL) with OR of 0.30 (95% CI: 0.13-0.72; P = 0.007), compared with 25 (OH) D deficiency (< 20 ng / mL). Furthermore, results with 25 (OH) D as a linear variable indicated that each 10 ng / mL increment of plasma 25 (OH) D corresponded to a 12% decrease in RCC risk. Conclusions: This case-control study on a Chinese Han population supports the protective effect of a higher circulating concentration of 25 (OH) against RCC, whether the confounding factors are adjusted or not.

A modified method by differential adhesion for enrichment of bladder cancer stem cells

ABSTRACT Purpose: In a previous study the vaccine was effective against bladder cancer in a mouse model. However, a small portion of tumors regrew because the vaccine could not eliminate bladder cancer stem cells (CSCs). In this study, we showed a modified method for the isolation of bladder CSCs using a combination of differential adhesion method and serum-free culture medium (SFM) method. Materials and Methods: Trypsin-resistant cells and trypsin-sensitive cells were isolated from MB49, EJ and 5637 cells by a combination of differential adhesion method and SFM method. The CSCs characterizations of trypsin-resistant cells were verified by the flow cytometry, the western blotting, the quantitative polymerase chain reaction, the resistance to chemotherapy assay, the transwell assay, and the tumor xenograft formation assay. Results: Trypsin-resistant cells were isolated and identified in CSCs characters, with high expression of CSCs markers, higher resistance to chemotherapy, greater migration in vitro, and stronger tumorigenicity in vivo. Conclusion: Trypsin-resistant cells displayed specific CSCs properties. Our study showed trypsin-resistant cells were isolated successfully with a modified method using a combination of differential adhesion method and SFM method.