Significant prolongation of animal survival by combined therapy of FR167653 and cyclosporine A in rat renal allografts.

BACKGROUND: Cyclosporine A (CsA) has improved short-term results in renal transplantation. However, its toxicities have been serious problems in clinical patients undergoing long-term administration. It is necessary to develop a nonnephrotoxic immunosuppressant that allows reducing doses of CsA. The authors tested the effect of a new pyrazolotriazin compound, FR167653 (FR), that inhibits the production of proinflammatory cytokines, using a rat renal acute-rejection model (Wistar-Lewis). METHODS: The authors first examined the adverse reactions of FR in naive rats. The effect of FR monotherapy was evaluated by treating allograft recipients at a dosage of 32 or 64 mg/kg/day intraperitoneally. The synergistic effect of FR and CsA at a minimum dose was examined by treating the recipients daily with 64 mg/kg of FR and 0.1, 0.5, or 1.0 mg/kg of CsA. RESULTS: Long-term administration of FR caused no severe adverse reactions in naive rats at less than 96 mg/kg/day, and FR is a nonnephrotoxic but liver-toxic agent at higher doses. Monotherapy of FR (8.7+/-1.3 days) or CsA (8.7+/-1.7 days) did not influence graft survival (vs. 8.2+/-0.8 in controls, n=10). However, the combined treatment of FR and CsA significantly prolonged animal survival (>50% of animals survived a 42-day follow-up period; P<0.01 vs. all other groups, n=15/group). Immunologic analysis demonstrated the significantly decreased production of major inflammatory mediators and adhesion molecules in the allografts as compared with those of all other groups. CONCLUSIONS: A nonnephrotoxic agent, FR may be a promising candidate for a new combined immunosuppressive regimen that potentially reduces the amount of CsA.

Selective cancer cell apoptosis induced by FTY720; evidence for a Bcl-dependent pathway and impairment in ERK activity.

BACKGROUND: FTY720 is a unique immunosuppressant that induces apoptosis in activated lymphocytes, but not in other hematopoietic cells. We conducted the present study to investigate its anticancer effect and molecular pathway in inducing apoptosis using murine breast cancer models. MATERIALS AND METHODS: The difference in drug susceptibility to FTY720 between cancer cells and non-cancer cells was examined by MTT assay and cell growth assay. FTY720-induced apoptosis was determined by electron microscopy and DNA electrophoresis, and its molecular pathway was evaluated by Western blot analysis. We then tested in vivo the effect of this agent using two murine breast cancer models. RESULTS: FTY720 treatment induced selective cancer cell apoptosis in vitro at a concentration of less than 10 microM. In vivo tumor growth was significantly prevented with induction of apoptosis in both models without any severe systemic adverse reactions. The evaluation of intracellular protease activity demonstrated that FTY720-induced apoptosis was mediated by a Fas-independent, Bcl-associated signal transduction pathway. Inhibition of extracellular signal-regulated kinase (ERK) activity may be involved in its underlying mechanism of action. CONCLUSION: FTY720 may be a promising candidate for a new anticancer therapy, which potentially induces selective apoptosis in cancer cells.

Susceptibility gene for non-obstructive azoospermia located near HLA-DR and -DQ loci in the HLA class II region.

The technical developments and expanded indications for testicular sperm extraction (TESE) with intracytoplasmic sperm injection (ICSI) provide great advantages for patients with non-obstructive azoospermia. Such success, however, also means that genetic abnormalities in non-obstructive azoospermia can be transmitted to the next generation, demonstrating the importance of being able to understand the genetic background of non-obstructive azoospermia. We have previously reported that human leukocyte antigens (HLA)-A33 and -B44 in the HLA class I region and the HLA-DRB1*1302 allele in the HLA class II region are linked to susceptibility to non-obstructive azoospermia in Japanese men. However, strong linkage of HLA-DRB1*1302 with HLA-A33 and -B44 is also evident in the Japanese population. Thus, uncertainty prevails as to whether the HLA class I or class II molecule is more directly associated with non-obstructive azoospermia. In the present study, we performed association analysis with 21 polymorphic microsatellite markers identified near the HLA genes to map the gene involved in the development of non-obstructive azoospermia more precisely. Microsatellite markers located in the HLA class I region or the class III region showed no statistically significant association with this disorder, although once again the HLA-A33 and -B44 alleles showed a significant association. In contrast, some of the microsatellite markers in the HLA class II region and at the HLA-DRB1 and -DQB1 loci displayed strong associations with non-obstructive azoospermia. Taken together, our previous and present data suggest that the critical region for development of non-obstructive azoospermia is near the HLA-DRB1 and -DQB1 segments in the HLA class II region.