Transient Receptor Potential Vanilloid 1 Expression and Functionality in MCF-7 Cells: A Preliminary Investigation

PURPOSE: Transient receptor potential vanilloid 1 (TRPV1) is a nonselective cation channel belonging to the transient receptor potential family, and it is expressed in different neoplastic tissues. Its activation is associated with regulation of cancer growth and progression. The aim of this research was to study the expression and pharmacological characteristics of TRPV1 in cells derived from human breast cancer MCF-7 cells. METHODS: TRPV1 presence was assessed by binding studies and Western blotting. Receptor binding characteristics were evaluated through competition assays, while 3-(4,5-dimethylthiazol-2-yl)-2,5,-dipheyltetrazolium bromide reduction assays were performed to confirm an early hypothesis regarding the modulation of cancer cell proliferation. The functionality of TRPV1 was evaluated by measuring Ca(2+) uptake in the presence of increasing concentrations of TRPV1 agonists and antagonists. RESULTS: Binding studies identified a single class of TRPV1 (B(max) 1,492±192 fmol/mg protein), and Western blot showed a signal at 100 kDa corresponding to the molecular weight of human TRPV1. Among the different tested agonists and antagonists, anandamide (Ki: 2.8×10(-11) M) and 5-iodoresiniferatoxin (5-I-RTX) (Ki: 5.6×10(-11) M) showed the highest degrees of affinity for TRPV1, respectively. All tested TRPV1 agonists and antagonists caused a significant (p<0.05) decrease in cell growth rate in MCF-7 cells. For agonists and antagonists, the efficacy of tested compounds displayed the following rank order: resiniferatoxin>anandamide>capsaicin and 5-I-RTX=capsazepine, respectively. CONCLUSION: These data indicate that both TRPV1 agonists and antagonists induce significant inhibition of MCF-7 cell growth. Even though the mechanisms involved in the antiproliferative effects of TRPV1 agonists and antagonists should be further investigated, it has been suggested that agonists cause desensitization of the receptor, leading to alteration in Ca(2+)-influx regulation. By contrast, antagonists cause a functional block of the receptor with consequent fatal dysregulation of cell homeostasis

Detection of Leptospira spp. in Water Turtle (Trachemys scripta) Living in Ponds of Urban Parks

Urban parks are green areas of cities where families and children spend hours outside. Turtles often inhabit urban parks. However, even if the animals seem harmless, they may serve as both reservoirs or accidental hosts for different serotypes of Leptospira spp. Leptospira spp. is a waterborne zoonotic bacterium relevant for public health. Reptiles and amphibians may play a role in the epidemiology, transmission, and persistence of Leptospira spp. In the present study, we observed the presence of anti-leptospiral agglutinins in a group of freshwater turtles (Trachemys scripta) captured in three urban ponds of the metropolitan city of Turin, Italy