Toll-like receptor 4 is a therapeutic target for prevention and treatment of liver failure.

BACKGROUND & AIMS: Toll-like receptor 4 (TLR4) plays an essential role in mediating organ injury in acute liver failure (ALF) and acute-on-chronic liver failure (ACLF). Herein, we assess whether inhibiting TLR4 signaling can ameliorate liver failure and serve as a potential treatment. METHODS: Circulating TLR4 ligands and hepatic TLR4 expression were measured in plasma samples and liver biopsies from patients with cirrhosis. TAK-242 (TLR4 inhibitor) was tested in vivo (10 mg/kg intraperitoneally) in rodent models of ACLF (bile duct ligation + lipopolysaccharide [LPS]; carbon tetrachloride + LPS) and ALF (galactosamine + LPS) and in vitro on immortalized human monocytes (THP-1) and hepatocytes (HHL5). The in vivo therapeutic effect was assessed by coma-free survival, organ injury and cytokine release and in vitro by measuring IL-6, IL-1ß or cell injury (TUNEL), respectively. RESULTS: In patients with cirrhosis, hepatic TLR4 expression was upregulated and circulating TLR4 ligands were increased (p <0.001). ACLF in rodents was associated with a switch from apoptotic cell death in ALF to non-apoptotic forms of cell death. TAK-242 reduced LPS-induced cytokine secretion and cell death (p = 0.002) in hepatocytes and monocytes in vitro. In rodent models of ACLF, TAK-242 administration improved coma-free survival, reduced the degree of hepatocyte cell death in the liver (p <0.001) and kidneys (p = 0.048) and reduced circulating cytokine levels (IL-1ß, p <0.001). In a rodent model of ALF, TAK-242 prevented organ injury (p <0.001) and systemic inflammation (IL-1ß, p <0.001). CONCLUSION: This study shows that TLR4 signaling is a key factor in the development of both ACLF and ALF; its inhibition reduces the severity of organ injury and improves outcome. TAK-242 may be of therapeutic relevance in patients with liver failure. LAY SUMMARY: Toll-like receptor 4 (or TLR4) mediates endotoxin-induced tissue injury in liver failure and cirrhosis. This receptor sensitizes cells to endotoxins, which are produced by gram-negative bacteria. Thus, inhibiting TLR4 signaling with an inhibitor (TAK-242) ameliorates organ injury and systemic inflammation in rodent models of acute and acute-on-chronic liver failure.

Evidence of estrone-sulfate uptake modification in young and middle-aged rat prostate.

High plasma exposure to estrogens is often associated with prostate cancer. Reducing this phenomenon may present therapeutic benefits. The involvement of estrone sulphate (E1S), the most abundant circulating estrogen in men, has been partially studied in this age-related pathology. To investigate the consequences of plasma E1S overload on blood and prostate sex steroid levels and inflammatory tissue responses, young and middle-aged male rats were treated with E1S with or without steroid sulfatase (STS) inhibitor STX64 for 21 consecutive days. A plasma and prostate tissue steroid profile was determined. STS activity, mRNA expression of E1S organic anion transporting polypeptides (slco1a2, slco2b1, slco4a1) and pro-inflammatory cytokines (Il1-beta, Il6, TNF-alpha) were evaluated in prostate tissue according to age and treatment group. A significant correlation between plasma and prostate steroid levels related to hormone treatment was observed in all rat age groups. However, while the E1S level in prostate tissue increased in middle-aged treated rats (p<0.0001), no significant variation was observed in young treated rats. The protective effect of STX64 during E1S infusion was observed by the maintenance of low free estrogen concentrations in both plasma and tissue. However, this protection was not associated with mRNA expression stability of pro-inflammatory cytokines in older rat prostate. These results suggest that E1S uptake in rat prostate cells increases during aging. Therefore, if a similar phenomenon existed in men, preventively reducing the STS activity could be of interest to limit uptake of estrogens in prostate when high E1S plasma level is assayed.

A phase I dose escalation study to determine the optimal biological dose of irosustat, an oral steroid sulfatase inhibitor, in postmenopausal women with estrogen receptor-positive breast cancer.

Steroid sulfatase (STS) inhibition may have a therapeutic role in suppression of endocrine-responsive breast cancer. This study aimed to determine the optimal biological dose and recommended dose (RD) of the STS inhibitor irosustat. A three-part, open-label, multicenter, dose escalation study of irosustat in estrogen receptor-positive breast cancer patients involved administration of a single dose of irosustat with a 7-day observation period; followed by a daily oral dose of irosustat for 28 days; and an extension phase, in which the daily oral dose of irosustat was continued at the discretion of the investigator and as long as the patient was benefitting from the treatment. Five doses of irosustat were tested (1, 5, 20, 40, and 80 mg) in 50 patients. After 28 days of daily administration of irosustat, all the evaluated patients in the 5, 20, 40, and 80 mg cohorts achieved ≥95 % STS inhibition in peripheral blood mononuclear cells and corresponding endocrine suppression. The maximum tolerated dose was not reached, and the 40 mg dose was established as the RD. The median time to disease progression in the 40 mg cohort was 11.2 weeks. Disease stabilization was achieved in 10 % of patients potentially indicative of drug activity. Dry skin was the most frequent adverse event. The RD of irosustat is 40 mg. Disease stabilization occurred in 10 % of this heavily pretreated patient population. A larger study is required to define an accurate response rate to irosustat as a single agent and whether co-administration with an aromatase inhibitor is needed.

A comparison of two orally bioavailable anti-cancer agents, IRC-110160 and STX140.

UNLABELLED: This study characterises two recently developed anticancer agents in vitro and in vivo, 2-methoxyoestra-1,3,5(10), 16-tetraene-3-carboxamide (IRC-110160) and STX140. MATERIALS AND METHODS: Hormone-dependent (MCF-7), hormone-independent (MDA-MB-231) and P-glycoprotein overexpressing (MCF-7Dox) cells were used for proliferation experiments. For the tumour efficacy studies, female nude mice were inoculated with MDA-MB-231 cells. RESULTS: IRC-110160 is a potent inhibitor of both MCF-7 and MDA-MB-231 cell proliferation. Furthermore, the potency of IRC-110160 was unaffected by the over-expression of the P-glycoprotein drug efflux pump. IRC-110160 and 2-methoxyoestradiol-3,17-O,O-bis-sulfamate (STX140) induced apoptosis in a similar timeframe in the MDA-MB-231 cell line, but only STX140 caused G2/M arrest in these cells. In the MDA-MB-231 xenograft model 300 mg/kg p.o. (daily) of IRC-110160 and 20 mg/kg p.o. STX140 (daily) both completely inhibited tumour growth; however some toxicity was observed with IRC-110160. After 28 days of daily dosing STX140 (20 mg/kg p.o.) had minimal effect on the white blood population of mice with tumours. The masking of STX140 from white blood cells may be due to its interaction with carbonic anhydrase II (CAII) in the red blood cells. In contrast to STX140, IRC-110160 does not inhibit CAII. These studies highlight the activity of two orally bioavailable anti-cancer agents one of which, STX140, may offer a significant clinical advantage over existing drugs as a common dose limiting factor, haemotoxicity, may be minimised.

A new micronized formulation of 2-methoxyestradiol-bis-sulfamate (STX140) is therapeutically potent against breast cancer.

UNLABELLED: There is a continued need for orally bioavailable anticancer compounds that exhibit good efficacy against breast cancer. STX140, a derivative of 2-methoxyestradiol (2-MeOE2), has been shown to have excellent oral bioavailability and significantly reduces tumor growth. A new micronized formulation of STX140 has now been developed and its pharmacokinetics (PK) in rats and effect on MDA-MB-231 breast cancer growth in nude mice was investigated. MATERIALS AND METHODS: For the PK studies, female Wistar rats were treated orally with STX140 in two separate vehicles (10% tetrahydrofuran (THF) in propylene glycol (PG) or 0.5% methyl cellulose (MC) in saline) and plasma samples taken for high performance liquid chromatography analysis over 48 h. For the tumor efficacy studies, female nude mice were inoculated with MDA-MB-231 breast cancer cells and then treated orally with a range of doses of STX140. RESULTS: The PK studies demonstrated that the THF/PG vehicle resulted in a greater oral bioavailability of STX140 compared to the 0.5% MC vehicle. However, this was not translated to the tumor efficacy studies where STX140 at 20 mg/kg in either vehicle caused a significant reduction in tumor volume. CONCLUSION: The new micronized formulation of STX140 is orally bioavailable and efficacious at inhibiting MDA-MB-231 breast tumor growth.

Effect of galantamine hydrobromide in chronic fatigue syndrome: a randomized controlled trial.

CONTEXT: There is no established pharmacological treatment for the core symptoms of chronic fatigue syndrome (CFS). Galantamine hydrobromide, an acetyl cholesterone inhibitor, has pharmacological properties that might benefit patients with CFS. OBJECTIVE: To compare the efficacy and tolerability of galantamine hydrobromide in patients with CFS. DESIGN, SETTING, AND PATIENTS: Randomized, double-blind trial conducted June 1997 through July 1999 at 35 outpatient centers in the United Kingdom (n = 17), United States (n = 14), the Netherlands (n = 2), Sweden (n = 1), and Belgium (n = 1) involving 434 patients with a clinical diagnosis of CFS (modified US Centers for Disease Control and Prevention criteria). INTERVENTIONS: A total of 89 patients were randomly assigned to receive 2.5 mg of galantamine hydrobromide; 86 patients, 5.0 mg; 91 patients, 7.5 mg; and 86 patients, 10 mg (these patients received medicine in the tablet form 3 times per day); a total of 82 patients received matching placebo tablets 3 times per day. MAIN OUTCOME MEASURES: The primary efficacy variable was the global change on the Clinician Global Impression Scale after 4, 8, 12, and 16 weeks of treatment. Secondary outcomes were changes in core symptoms of CFS on the Chalder Fatigue Rating Scale, the Fibromyalgia Impact Questionnaire, and the Pittsburgh Sleep Quality Index; changes in quality of life on the Nottingham Health Profile; and assessment of plasma-free cortisol levels and cognitive performance on a computer-based battery of tests. RESULTS: After 16 weeks, there were no statistically significant differences between any of the galantamine or placebo groups in clinical condition on the Clinician Global Impression Scale, or for any of the secondary end points. Exploratory regression analysis failed to detect any consistent prognostic factor that might have influenced the primary or any secondary outcome measures. CONCLUSION: This trial did not demonstrate any benefit of galantamine over placebo in the treatment of patients with CFS.