Various accumulating evidence suggests that survivin, a member of the inhibitor of apoptosis (IAP) family, plays an important role in drug resistance and cancer cell survival in many types of cancer, including hormone-refractory prostate cancer (HRPC). Here, we characterized YM155, a novel smallmolecule survivin suppressant, using a survivin gene promoter activity assay. YM155 suppressed expression of survivin and induced apoptosis in PC-3 and PPC-1 human HRPC cell lines at 10 nmol/L. In contrast, YM155 up to 100 nmol/L showed little effect on expression levels of other IAP-or Bcl-2-related proteins. In a s.c. xenografted PC-3 tumor model in mice, 3-day continuous infusions of YM155 at 3 to 10 mg/kg induced massive tumor regression accompanied by suppression of intratumoral survivin. YM155 also completely inhibited the growth of orthotopically xenografted PC-3 tumors. No significant decreases in body weight were observed in mice treated with YM155 during the experimental period. Pharmacokinetic analyses indicated that YM155 is highly distributed to tumors and at concentrations f20-fold higher than those in plasma. Our findings represent the first attempt to show tumor regression and suppression of survivin in p53-deficient human HRPC cells by a single small molecular compound treatment. Further extensive investigation of YM155 in many types of cancer, including HRPC, seems to be worthwhile to develop this novel therapeutic approach. [Cancer Res 2007; 67(17):8014-21]

We evaluated the pharmacological characteristics of (R)-2-(2-aminothiazol-4-yl)-4Ј-{2-[(2-hydroxy-2-phenylethyl)amino]-ethyl} acetanilide (YM178). YM178 increased cyclic AMP accumulation in Chinese hamster ovary (CHO) cells expressing human ␤ 3 -adrenoceptor (AR). The half-maximal effective concentration (EC 50 ) value was 22.4 nM. EC 50 values of YM178 for human ␤ 1 -and ␤ 2 -ARs were 10,000 nM or more, respectively. The ratio of intrinsic activities of YM178 versus maximal response induced by isoproterenol (nonselective ␤-AR agonist) was 0.8 for human ␤ 3 -ARs, 0.1 for human ␤ 1 -ARs, and 0.1 for human ␤ 2 -ARs. The relaxant effects of YM178 were evaluated in rats and humans bladder strips precontracted with carbachol (CCh) and compared with those of isoproterenol and 4-[3-[(1,1-dimethylethyl)amino]-2-hydroxypropoxy]-1,3-dihydro-2H-benzimidazol-2-one hydrochloride (CGP-12177A) (␤ 3 -AR agonist). EC 50 values of YM178 and isoproterenol in rat bladder strips precontracted with 10 Ϫ6 M CCh were 5.1 and 1.4 M, respectively, whereas those in human bladder strips precontracted with 10 Ϫ7 M CCh were 0.78 and 0.28 M, respectively. In in vivo study, YM178 at a dose of 3 mg/kg i.v. decreased the frequency of rhythmic bladder contraction induced by intravesical filling with saline without suppressing its amplitude in anesthetized rats. These findings suggest the suitability of YM178 as a therapeutic drug for the treatment of symptoms of overactive bladder such as urinary frequency, urgency, and urge incontinence.

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Nitric oxide (NO) is a new intercellular messenger that occurs naturally in the brain without causing overt toxicity. Yet, NO has been implicated as a mediator of cell death in cell death. One explanation is that ischemia causes overproduction of NO, allowing it to react with superoxide to form the potent oxidant peroxynitrite. To address this question, we used immunohistochemistry for citrulline, a marker for NO synthase activity, and 3-nitrotyrosine, a marker for peroxynitrite formation, in mice subjected to reversible middle cerebral artery occlusion. We show that ischemia triggers a marked augmentation in citrulline immunoreactivity but more so in the peri-infarct than the infarcted tissue. This increase is attributable to the activation of a large population (approximately 80%) of the neuronal isoform of NO synthase (nNOS) that is catalytically inactive during basal conditions, indicating a tight regulation of physiological NO production in the brain. In contrast, 3-nitrotyrosine immunoreactivity is restricted to the infarcted tissue and is not present in the peri-infarct tissue. In nNOS(Delta/Delta) mice, known to be protected against ischemia, no 3-nitrotyrosine immunoreactivity is detected. Our findings provide a cellular localization for nNOS activation in association with ischemic stroke and establish that NO is not likely a direct neurotoxin, whereas its conversion to peroxynitrite is associated with cell death.

Antitumor activities of YM155, a novel small-molecule survivin suppressant, were investigated in a wide variety of human cancer cell lines and xenograft models. YM155 inhibited the growth of 119 human cancer cell lines, with the greatest activity in lines derived from non-Hodgkin's lymphoma, hormone-refractory prostate cancer, ovarian cancer, sarcoma, non-small-cell lung cancer, breast cancer, leukemia and melanoma. The mean log growth inhibition of 50% (GI 50 ) value was 15 nM. The mean GI 50 values of YM155 were 11 nM for p53 mut/null cell lines and 16 nM for p53 WT cell lines, suggesting that YM155 inhibits the growth of human tumor cell lines regardless of their p53 status. In non-small-cell lung cancer (Calu 6, NCI-H358), melanoma (A375), breast cancer (MDA-MB-231) and bladder cancer (UM-UC-3) xenograft models, 3-or 7-day continuous infusions of YM155 (1-10 mg/kg) demonstrated significant antitumor activity without showing significant bodyweight loss. Tumor regressions induced by YM155 were associated with reduced intratumoral survivin expression levels, increased apoptosis and decreased mitotic indices. The broad and potent antitumor activity presented in the present study is indicative of the therapeutic potential of YM155 in the clinical setting. (Cancer Sci 2011; 102: 614-621)

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The pharmacological profile of ipragliflozin (ASP1941; (1S)-1,5-anhydro-1-C-{3-[(1-benzothiophen-2-yl)methyl]-4-fluorophenyl}-D: -glucitol compound with L: -proline (1:1)), a novel SGLT2 selective inhibitor, was investigated. In vitro, the potency of ipragliflozin to inhibit SGLT2 and SGLT1 and stability were assessed. In vivo, the pharmacokinetic and pharmacologic profiles of ipragliflozin were investigated in normal mice, streptozotocin-induced type 1 diabetic rats, and KK-A(y) type 2 diabetic mice. Ipragliflozin potently and selectively inhibited human, rat, and mouse SGLT2 at nanomolar ranges and exhibited stability against intestinal glucosidases. Ipragliflozin showed good pharmacokinetic properties following oral dosing, and dose-dependently increased urinary glucose excretion, which lasted for over 12 h in normal mice. Single administration of ipragliflozin resulted in dose-dependent and sustained antihyperglycemic effects in both diabetic models. In addition, once-daily ipragliflozin treatment over 4 weeks improved hyperglycemia with a concomitant increase in urinary glucose excretion in both diabetic models. In contrast, ipragliflozin at pharmacological doses did not affect normoglycemia, as was the case with glibenclamide, and did not influence intestinal glucose absorption and electrolyte balance. These results suggest that ipragliflozin is an orally active SGLT2 selective inhibitor that induces sustained increases in urinary glucose excretion by inhibiting renal glucose reabsorption, with subsequent antihyperglycemic effect and a low risk of hypoglycemia. Ipragliflozin has, therefore, the therapeutic potential to treat hyperglycemia in diabetes by increasing glucose excretion into urine.