A preliminary assessment of oral monepantel's tolerability and pharmacokinetics in individuals with treatment-refractory solid tumors.

PURPOSE: Monepantel is an approved veterinary anthelmintic with a strong safety profile. Preclinical evidence suggests novel mTOR pathway-associated anticancer activity. An open-label Phase I trial assessed tolerability, pharmacokinetics, pharmacodynamics and PET-CT imaging following oral Zolvix® monepantel administration to adults with treatment refractory, progressing and unresectable solid tumors. METHODS: Subjects were scheduled to daily home-based monepantel administration for 28 days in a 3 + 3 dose escalation study (5.0, 25.0 and 62.5 mg/kg bw). RESULTS: Of 41 reported drug-related AEs, 68% were Grade 1 and 24% were Grade 2; 35 AEs related to gastrointestinal effects including very poor palatability. DLT and MTD could not be determined due to early termination. Myelosuppression was not observed at the lowest level tested. Three of four Cohort 1 subjects had reduced mTOR pathway marker p-RPS6KB1 levels in PBMCs and achieved RECISTv1.1 SD by CT; one had progressive bony metastases by FDG-PET. One subject recorded PD on day 28, correlating with no detectable plasma monepantel from day 7. Monepantel sulfone dominated monepantel in pharmacokinetics. Both Cohort 2 subjects withdrew early due to AEs and the trial was terminated. CONCLUSIONS: Short-term 5 mg/kg bw monepantel administration provides a combined steady-state trough plasma monepantel and monepantel sulfone concentration of 0.5 µM. Gastrointestinal AEs including very poor palatability are concerning and suggested to be resolved by future drug product reformulation. RECISTv1.1, p-RPS6KB1 and plasma tumor marker outcomes provide preliminary evidence of anticancer activity.

Nf1 deletion results in depletion of the Lhx6 transcription factor and a specific loss of parvalbumin+ cortical interneurons.

Neurofibromatosis 1 (NF1) is caused by mutations in the NF1 gene, which encodes the protein, neurofibromin, an inhibitor of Ras activity. Cortical GABAergic interneurons (CINs) are implicated in NF1 pathology, but the cellular and molecular changes to CINs are unknown. We deleted mouse Nf1 from the medial ganglionic eminence, which gives rise to both oligodendrocytes and CINs that express somatostatin and parvalbumin. Nf1 loss led to a persistence of immature oligodendrocytes that prevented later-generated oligodendrocytes from occupying the cortex. Moreover, molecular and cellular properties of parvalbumin (PV)-positive CINs were altered by the loss of Nf1, without changes in somatostatin (SST)-positive CINs. We discovered that loss of Nf1 results in a dose-dependent decrease in Lhx6 expression, the transcription factor necessary to establish SST+ and PV+ CINs, which was rescued by the MEK inhibitor SL327, revealing a mechanism whereby a neurofibromin/Ras/MEK pathway regulates a critical CIN developmental milestone.

Losses caused by gastrointestinal nematode infections in Dorper lambs under two nutritional status / Prejuízos causados pelas infecções por nematoides gastrintestinais em cordeiros Dorper submetidos a dois manejos nutricionais

Abstract The aim of this study was to evaluate the effect of two nutritional statuses on the productive performance of Dorper lambs naturally infected with gastrointestinal nematodes. Thirty-two lambs, grazing together on the same pasture, were allocated into four experimental groups: (G1) infected-supplemented diet, (G2) control-supplemented diet, (G3) infected-basal diet, and (G4) control-basal diet. Control animals received suppressive treatment with monepantel every two weeks, while precautionary anthelmintic treatments were given to all lambs of the infected groups with packed cell volume (PCV) <23%. There was reduction in the PCV means of all groups, which was more pronounced in the infected lambs that also presented reduction in total plasma protein values in comparison with the controls. Weight gain was affected by diet and infection status (P < 0.05). Daily body weight gain was 0.170 kg in the G1, 0.205 kg in the G2, 0.085 kg in the G3, and 0.116 kg in the G4. The cold carcass weight was 4.1% and 13.7% higher in controls in comparison with infected lambs, respectively, in the supplemented and basal diets. The infected groups, despite receiving precautionary anthelmintic treatments to prevent deaths due to haemonchosis, presented reduction in the production parameters in comparison with the controls.

Resumo O experimento teve por objetivo determinar o efeito de dois níveis de nutrição no desempenho produtivo de cordeiros Dorper naturalmente infectados por nematoides gastrintestinais. Trinta e dois cordeiros, mantidos juntos na mesma pastagem, foram alocados em quatro grupos experimentais: (G1) infectado-suplementado, (G2) controle-suplementado, (G3) infectado-dieta basal e (G4) controle-dieta basal. Os cordeiros suplementados receberam diariamente concentrado em quantidade equivalente a 2% do peso corporal (PC), enquanto na dieta basal receberam apenas uma pequena quantidade de concentrado (0,35% do PC). Os animais controles receberam tratamento supressivo com anti-helmíntico a cada duas semanas e os infectados foram tratados individualmente quando apresentaram volume globular (VG) <23%. Houve redução nas médias de VG em todos os grupos, as quais foram mais pronunciadas nos animais dos grupos infectados, que também apresentaram redução nos valores de proteína plasmática total em comparação com os controles. Houve efeito significativo da dieta e da infecção no ganho de peso (P <0,05). O ganho em peso diário foi de 0,170 kg no G1, 0,205 kg no G2, 0,085 kg no G3 e 0,116 kg no G4. Os grupos infectados, apesar de receberem tratamentos anti-helmínticos preventivos que evitaram mortes por haemonchose, apresentaram redução nos parâmetros produtivos em comparação com os controles.

Anthelminthic resistance of gastrointestinal nematodes in sheep to monepantel treatment in central region of Rio Grande do Sul, Brazil / Resistência anti-helmíntica de nematódeos gastrointestinais de ovinos ao monepantel na região central do Rio Grande do Sul

Given the numerous reports of anthelminthic resistance of sheep nematodes to different anthelmintic compounds, this study aimed to evaluate the resistance status of gastrointestinal nematodes from naturally infected sheep to monepantel in the state of Rio Grande do Sul. Four farms that present extensive raising system and absence of anthelmintic treatment for 60 days were selected for the study. Lambs that present counts of eggs per gram of feces (EPG) ≥200 (sensitivity of 50 EPG) one day (D-1) before the treatment were select for the study and randomly separated into two groups, a control group and an experimental group treated with monepantel. Feces were collected 9 days after the treatment (D+9) for EPG counts and fecal culture. The monepantel was 100% effective only on 2. The efficacy found on farm 1, 3, and 4 were 2.82%, 25.8%, and 78.4%, respectably. There were no viable larvae post-treatment at farm 2, but the genera Haemonchus, Trichostrongylus, Cooperia, and Strongyloides were resistant to it at the other farms. This study shows the presence of parasites resistant to the treatment with monepantel, pointing to the importance of monitoring its efficacy in sheep flocks of Rio Grande do Sul, Brazil.(AU)

Devido aos numerosos relatos de resistência anti-helmíntica de nematódeos gastrintestinais de ovinos a diferentes compostos, este estudo objetivou avaliar o status da resistência de nematódeos gastrintestinais de ovinos naturalmente infectados ao monepantel no estado do Rio Grande do Sul. Quatro fazendas que apresentam sistema extensivo de criação e ausência de tratamento anti-helmíntico por 60 dias foram selecionados para o estudo. Animais que apresentassem as contagens de ovos por grama de fezes (OPG) ≥200 (sensibilidade de 50 OPG) um dia (D-1) antes do tratamento foram selecionados para o estudo e separados em dois grupos, um grupo controle e um grupo experimental tratado com monepantel. Fezes foram coletadas nove dias após o tratamento (D + 9) para realização do OPG e cultura fecal. O monepantel foi 100% eficaz apenas na propriedade 2. A eficácia encontrada nas propriedades 1, 3 e 4 foi 2,82%, 25,8% e 78,4%, respectivamente. Não houveram larvas viáveis após o tratamento nas propriedades 2, porém os gêneros Haemonchus, Trichostrongylus, Cooperia e Strongyloides demonstraram resistência a este nas demais propriedades. Este estudo mostra a presença de parasitas resistentes ao tratamento com monepantel, apontando para a importância de monitorar a sua eficácia em rebanhos de ovinos do Rio Grande do Sul, Brasil.(AU)

The effect of mTOR inhibition alone or combined with MEK inhibitors on brain metastasis: an in vivo analysis in triple-negative breast cancer models.

mTOR inhibitor rapamycin and its analogs are lipophilic, demonstrate blood-brain barrier penetration, and have shown promising antitumor effects in several types of refractory tumors. We thus try to explore the therapeutic effects of mTOR inhibitors on brain metastasis models. We examined the effects of different dose of mTOR inhibitors (rapamycin, Temsirolimus-CCI-779) on cell invasion in two brain metastatic breast cancer cell lines (MDA-MB231-BR and CN34-BrM2). Antibody microarray and immunoblotting were applied to detect signaling pathways underlying the dose differential drug effects. The in vivo effects of single drug (CCI-779), and drug combination of CCI-779 with SL327 (a brain penetrant MEK inhibitor) to eliminate the unfavorable activation of MAPK pathway were evaluated in MDA-MB231-BR brain metastases xenograft mice. The two mTOR inhibitors, rapamycin and CCI-779, inhibited the invasion of brain metastatic cells only at a moderate concentration level, which was lost at higher concentrations secondary to activation of the MAPK signaling pathway. Pharmacological inhibition of ERK1/2 by PD98059 and SL327 restored the anti-invasion effects of mTOR inhibition in vitro. In vivo, a significant decrease was noted in the average number of micro and large metastatic lesions as well as the whole brain GFP expression in the CCI-779 1 mg/kg/day treated group compared with that in the vehicle group (P < 0.05). However, 10 mg/kg CCI-779 treatment did not show significant anti-metastasis effect on the animal model. High-dose CCI-779 eliciting the ERK MAPK activation in the brain metastatic lesion was corroborated. Combined with the brain penetrant MEK inhibitor SL327, high-dose CCI-779 significantly reduces the brain metastasis, and the combination treatment prohibited perivascular invasion of tumor cells and inhibits tumor angiogenesis in vivo. This study provides evidence on the potential value of CCI-779 as well as CCI-779 + SL327 in prohibiting breast cancer brain metastasis.

Regulation of extracellular signal-regulated kinases (ERKs) by naloxone-induced morphine withdrawal in the brain stress system.

Our previous studies have shown that morphine withdrawal increases the hypothalamic-pituitary-adrenocortical axis activity, which is dependent on a hyperactivity of noradrenergic pathways (nucleus tractus solitarius-A(2)) innervating the hypothalamic paraventricular nucleus. The extracellular signal-regulated kinase has been implicated in drug addiction, but its role in activation of paraventricular nucleus and nucleus tractus solitarius during morphine dependence remain poorly understood. We have determined the activation of extracellular signal-regulated kinase during morphine dependence and withdrawal as well as its involvement in morphine withdrawal-induced gene expression. We show that naloxone-induced morphine withdrawal activates extracellular signal-regulated kinases(1/2) and increases c-Fos expression in rat paraventricular nucleus and nucleus tractus solitarius-A(2) neurons. Activated extracellular signal-regulated kinases(1/2) was colocalized with c-Fos in both nuclei, and this response was blocked by SL327, a drug that prevents extracellular signal-regulated kinase activation. In the paraventricular nucleus from morphine-withdrawn rats, the number of neurons expressing CRF was increased. Immunohistochemical study showed a dramatic increase in c-Fos immunoreactivity within CRF-positive cells. These results suggest that extracellular signal-regulated kinases1/2 signaling pathway is necessary for morphine withdrawal-induced activation of brain areas associated with the stress system.

IL-6 mediated alterations on immobile behavior of rats in the forced swim test via ERK1/2 activation in specific brain regions.

Interleukin-6 (IL-6), a proinflammatory cytokine, is well known as a mediator in early stage inflammatory immune reactions. In recent years, accumulating evidence has shown that IL-6 is concomitant with the occurrence of major depression. However, the identification of the role of IL-6, as either an illness causation or immunotherapy in depression, remains to be further established. In the present study, 5-week old male Sprague-Dawley (SD) rats were used along with the forced swim test (FST) and pharmacological techniques. The data show that rats subjected to 3-day intra-amygdala or intra-hippocampus, but not intra-frontal cortex, IL-6 treatments manifested a significant increase in the immobility time (IMT) in the FST. In addition, there was no obvious difference in body temperature between normal and 3-day IL-6 treated rats. Conversely, the rats receiving 3-day intra-amygdala or intra-hippocampus IL-6 inhibitor treatment expressed a significant reduction in IMT in the FST. Moreover, the 3-day IL-6 treated rats treated with SL 327, a blood-brain barrier penetrating MEK inhibitor, prior to the FST showed a significant decrease in the IL-6 elevated IMT. In addition, the results in the Western blot analysis were in parallel with those in the behavioral tests. Taken together, the results show that the immobile behavior of rats in the FST could be modulated by IL-6 via the amygdala or the hippocampus. Furthermore, the Erk1/2 activation in the amygdala or hippocampus seemed to play a role in the IL-6 mediated immobile behavioural alterations of rats in the FST.

Effects of lathyrogens on the mechanical strength of the periodontal ligament in the rat mandibular first molar.

Effects of lathyrogens such as aminoacetonitrile (AAN), beta-aminopropionitrile (BAPN) and cysteamine--known inhibitors of cross-linking of collagen--on the mechanical strength of the periodontal ligament of the rat mandibular first molar were examined by measuring the ultimate load required to extract the tooth from its socket in the dissected jaw. Single injections of AAN (40 approximately 100 mg/100 g body weight) or of BAPN (100 mg/100 g body weight) caused significant decreases of the mechanical strength 24 h after administration of the drugs but that of cysteamine (30 mg/100 g body weight) did not. Significant correlations between the dose of AAN or of BAPN and the mechanical strength were found following daily administrations of the drugs for 5 days. The relative potency of AAN to BAPN was estimated to be 4.5 by a slope ratio assay. The rapid appearance and disappearance of the effect of lathyrogens on the mechanical strength of the periodontal ligament of the rat mandibular first molar provide further evidence that the turnover of the collagen in the tissue is fast. The half-time of collagen synthesis was estimated to be approximately 3 d.