Cellular Migration Ability Is Modulated by Extracellular Purines in Ovarian Carcinoma SKOV-3 Cells.

Extracellular nucleotides and nucleosides have emerged as important elements regulating tissue homeostasis. Acting through specific receptors, have the ability to control gene expression patterns to direct cellular fate. We observed that SKOV-3 cells express the ectonucleotidases: ectonucleotide pyrophosphatase 1 (ENPP1), ecto-5'-nucleotidase (NT5E), and liver alkaline phosphatase (ALPL). Strikingly, in pulse and chase experiments supplemented with ATP, SKOV-3 cells exhibited low catabolic efficiency in the conversion of ADP into AMP, but they were efficient in converting AMP into adenosine. Since these cells release ATP, we proposed that the conversion of ADP into AMP is a regulatory node associated with the migratory ability and the mesenchymal characteristics shown by SKOV-3 cells under basal conditions. The landscape of gene expression profiles of SKOV-3 cell cultures treated with apyrase or adenosine demonstrated similarities (e.g., decrease FGF16 transcript) and differences (e.g., the negative regulation of Wnt 2, and 10B by adenosine). Thus, in SKOV-3 we analyzed the migratory ability and the expression of epithelium to mesenchymal transition (EMT) markers in response to apyrase. Apyrase-treatment favored the epithelial-like phenotype, as revealed by the re-location of E-cadherin to the cell to cell junctions. Pharmacological approaches strongly suggested that the effect of Apyrase involved the accumulation of extracellular adenosine; this notion was strengthened when the incubation of the SKOV-3 cell with α,ß-methylene ADP (CD73 inhibitor) or adenosine deaminase was sufficient to abolish the effect of apyrase on cell migration. Overall, adenosine signaling is a fine tune mechanism in the control of cell phenotype in cancer. J. Cell. Biochem. 118: 4468-4478, 2017. © 2017 Wiley Periodicals, Inc.

Hemodialysis: evidence of enhanced molecular clearance and ultrafiltration volume by using pulsatile flow.

We describe several in vitro experiments showing evidence that pulsatile flow hemodialysis enhances ultrafiltration volume and molecular clearance as compared with steady flow hemodialysis. A new pulsatile pump and a conventional roller pump were compared using different hollow fiber dialyzers and a simulated blood solution containing urea, aspartame and vitamin B-12 at different flow rates and configurations. Ultrafiltration volume and concentration of urea, aspartame and B-12 were measured and molecular clearance (K) calculated. Ultrafiltration volume markedly increased with pulsatile flow. After 10 min K for urea with pulsatile flow was higher in all experiments even when ultrafiltration was prevented. Clearance of aspartame and B-12 also increased with pulsatile flow. We propose three mechanisms by which pulsatile flow is more efficient than steady flow hemodialysis: greater fluid energy, avoidance of molecular channeling and avoidance of membrane layering. We hypothesize that using pulsatile flow in hemodialysis can significantly shorten the duration of dialysis sessions for most of the patients, and consequently reduce the duration of the procedure and its cost.

A prospective randomized trial of prednisone versus no prednisone maintenance therapy in cyclosporine-treated and azathioprine-treated renal transplant patients.

The purpose of this study was to evaluate early (6-12 days) prednisone withdrawal in cyclosporine- and azathioprine-treated renal transplant recipients. Patients, including 8 recipients of live-related donor kidneys and 59 recipients of cadaver donor kidneys, were prospectively randomized to receive maintenance prednisone (PRED) therapy or not (NOPRED) in addition to antilymphocyte globulin, cyclosporine, and azathioprine. Rejection episodes were initially treated with methylprednisolone pulses, and OKT3 monoclonal antibody was used to treat steroid resistant rejections that were verified by biopsy. NOPRED patients were declared protocol failures and returned to PRED therapy if they sustained 2 steroid-sensitive rejection episodes in the first 3 months or an OKT3-treated rejection at any time. Patient and graft survival for the LRD patients in both treatment categories were 100% at 12 months. Patient and graft survival for CAD recipients at one year was 94% and 83% (PRED) and 88% and 77% (NOPRED), respectively. Rejection episodes were more frequent (26 of 32 NOPRED patients vs. 19 of 35 PRED patients P = 0.02) and occurred earlier (4.5 weeks in NOPRED vs. 7.7 weeks in PRED patients) in patients not taking maintenance steroids. Rejection severity was also greater in the NOPRED group, as 15 OKT3-treated rejections occurred in that group whereas only 7 OKT3-treated rejections were observed in the PRED group (P = less than 0.01). The incidence of serious infection was similar in each group. Finally, protocol failure occurred in 40% of the LRD patients and 59% of the CAD patients. These data indicate that initiating maintenance therapy without PRED is safe but is attended by a greater risk of developing rejection. Because of this increased incidence and severity of early rejection episodes in NOPRED patients, we do not advise use of this immunosuppressive strategy in renal transplantation.