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mTORC1 promotes survival through translational control of Mcl-1.

Activation of the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway is a frequent occurrence in human cancers and a major promoter of chemotherapeutic resistance. Inhibition of one downstream target in this pathway, mTORC1, has shown potential to improve chemosensitivity. However, the mechanisms and genetic modifications that confer sensitivity to mTORC1 inhibitors remain unclear. Here, we demonstrate that loss of TSC2 in the E mu-myc murine lymphoma model leads to mTORC1 activation and accelerated oncogenesis caused by a defective apoptotic program despite compromised AKT phosphoryla

Survival signaling by Notch1: mammalian target of rapamycin (mTOR)-dependent inhibition of p53.

Notch signaling is believed to promote cell survival in general. However, the mechanism is not clearly understood. Here, we show that cells expressing intracellular domain of human Notch1 (NIC-1) are chemoresistant in a wild-type p53-dependent manner. NIC-1 inhibited p53 by inhibiting its activating phosphorylations at Ser(15), Ser(20), and Ser(392) as well as nuclear localization. In addition, we found that inhibition of p53 by NIC-1 mainly occurs through mammalian target of rapamycin (mTOR) using phosphatidylinositol 3-kinase (PI3K)-Akt/protein kinase B (PKB) pathway as the mTOR inhibitor, r

Target of rapamycin-dependent activation of S6 kinase is a central step in the transduction of nutritional signals during egg development in a mosquito.

Female mosquitoes are effective disease vectors, because they take blood from vertebrate hosts to obtain nutrients for egg development. Amino acid signaling via the target of rapamycin (TOR) pathway has been identified as a key requirement for the activation of egg development after a blood meal. We report the characterization of the TOR kinase and one of its major downstream targets, S6 kinase, of the yellow fever mosquito Aedes aegypti during egg development in adult females. Both TOR and S6K mRNA are expressed at high levels in the ovaries and in lower levels in fat body and other tissues.

Inhibition of human B lymphocyte cell cycle progression and differentiation by rapamycin.

In this study, we have analyzed the effects of the immunosuppressive agent rapamycin on the activation of highly purified normal human B lymphocytes. When the polyclonal activators Staphylococcus aureus (SA) and soluble CD40 ligand (CD40L) were used to stimulate B cells, rapamycin inhibited both interleukin 2 (IL2)-dependent and -independent proliferation, as well as IL2-dependent differentiation into antibody-secreting cells. Cell cycle analysis indicated that rapamycin inhibited the progression of SA+IL2-stimulated B cells past the mid-G1 phase of the cell cycle. To begin to identify rapamyc

The Role of mTOR Inhibitors in Hematologic Disease: From Bench to Bedside.

The mTOR pathway plays a central role in many cellular processes, such as cellular growth, protein synthesis, glucose, and lipid metabolism. Aberrant regulation of mTOR is a hallmark of many cancers, including hematological malignancies. mTOR inhibitors, such as Rapamycin and Rapamycin analogs (Rapalogs), have become a promising class of agents to treat malignant blood diseases-either alone or in combination with other treatment regimens. This review highlights experimental evidence underlying the molecular mechanisms of mTOR inhibitors and summarizes their evolving role in the treatment of he

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… | Sirolimus + Treg infusion + Low dose IL-2 8 | NCT02722668 | Sirolimus | 2 | GVHD | Recruiting | Sirolimus + MMF + ATG 9 | NCT03246906 | Sirolimus | 2 | GVHD | Recruiting | Sirolimus + CsA + MMF vs. … Sirolimus + CsA + PTCY 10 | ChiCTR2000029921 | Sirolimus | 2 | GVHD | Recruiting | Sirolimus + CNI 11 | NCT02583893 | Sirolimus | 2 | AML | Recruiting | Sirolimus + Mitoxantrone + Etoposide + Cytarabine 12 | NCT03878524 | Sirolimus, Everolimus | 1/2 | MDS, PMF | Recruiting | Sirolimus for MDS; Everolimus …

The specificity and role of microglia in epileptogenesis in mouse models of tuberous sclerosis complex.

OBJECTIVE: Microglial abnormalities have been reported in pathologic specimens from patients with tuberous sclerosis complex (TSC), a genetic disorder characterized by epilepsy, intellectual disability, and autism. However, the pathogenic role of microglia in epilepsy in TSC is poorly understood, particularly whether microglia defects may be a primary contributor to epileptogenesis or are secondary to seizures or simply epiphenomena. In this study, we tested the hypothesis that Tsc1 gene inactivation in microglia is sufficient to cause epilepsy in mouse models of TSC. METHODS: Using a chemoki

Blocking Mammalian Target of Rapamycin (mTOR) Alleviates Neuropathic Pain Induced by Chemotherapeutic Bortezomib.

BACKGROUND/AIMS: Bortezomib (BTZ) is largely used as a chemotherapeutic agent for the treatment of cancer. However, one of the significant limiting complications of BTZ is painful peripheral neuropathy during BTZ therapy. Drugs preventing and/or treating the painful symptoms induced by BTZ are lacking since the underlying mechanisms leading to neuropathic pain remain largely unclear. The purposes of this study were to examine 1) the effects of blocking mammalian target of rapamycin (mTOR) on mechanical pain and cold hypersensitivity evoked by BTZ and 2) the underlying mechanisms responsible fo

Report of a Chinese Cohort with Activated Phosphoinositide 3-Kinase δ Syndrome.

PURPOSE: We aimed to report the clinical manifestations and immunological features of activated phosphatidylinositol 3-kinase δ syndrome 1 (APDS1) in a Chinese cohort. Moreover, we investigated the efficacy and safety of rapamycin therapy for Chinese patients with APDS1. METHODS: Fifteen Chinese patients with APDS1 from 14 unrelated families were enrolled in this study. These patients were diagnosed based on clinical features, immunological phenotype, and whole-exome sequencing. Four patients were treated with rapamycin, and the clinical efficacy and safety of rapamycin were observed. The cha

Concomitant use of rapamycin and rosiglitazone delays the progression of polycystic kidney disease in Han:SPRD rats: a study of the mechanism of action.

Attributing to their antiproliferative effect, both rapamycin and peroxisome proliferator-activated receptor-γ (PPARγ) can halt the progression of autosomal dominant polycystic kidney disease (ADPKD). Whether combined use could enhance this effect is unknown. The present study used rapamycin and the PPARγ agonist rosiglitazone concomitantly to observe their combined effects on the proliferation of ADPKD cyst-lining epithelial cells and the progression of ADPKD in Han:SPRD rats. Concomitant use of the two drugs inhibited the proliferation of WT9-12 cells significantly through a superimposition

Comparative Case-Control analysis of a dedicated self-expanding Biolimus A9-eluting Bifurcation stent versus provisional or mandatory side branch intervention strategies in the treatment of coronary bifurcation lesions.

BACKGROUND: In a number of coronary bifurcation lesions, both the main vessel and the side branch (SB) need stent coverage. OBJECTIVES: To analyze the procedural performance and the impact on radiation times (RT) and contrast medium consumption (CMC) of the Axxess™ stent system (Biosensors, Switzerland) treating de novo bifurcation lesions (DBL). METHODS: One hundred and ten consecutive prospectively enrolled cases (Axxess Group) and 110 age, sex, and lesion location matched controls undergoing mandatory (Group A, n = 56) or provisional (Group B, n = 54) SB intervention were analyzed. RESUL

Paradoxical effect of rapamycin on inflammatory stress-induced insulin resistance in vitro and in vivo.

Insulin resistance is closely related to inflammatory stress and the mammalian target of rapamycin/S6 kinase (mTOR/S6K) pathway. The present study investigated whether rapamycin, a specific inhibitor of mTOR, ameliorates inflammatory stress-induced insulin resistance in vitro and in vivo. We used tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) stimulation in HepG2 hepatocytes, C2C12 myoblasts and 3T3-L1 adipocytes and casein injection in C57BL/6J mice to induce inflammatory stress. Our results showed that inflammatory stress impairs insulin signaling by reducing the expression of

Thrombotic complications associated with early and late nonadherence to dual antiplatelet therapy.

OBJECTIVES: This study sought to assess the frequency and clinical impact of dual antiplatelet therapy (DAPT) nonadherence. BACKGROUND: There are limited data on the impact of DAPT nonadherence during the first year after a second-generation drug-eluting stent placement. METHODS: After successful Endeavor zotarolimus-eluting stent implantation, 2,265 patients were enrolled in a registry with limited exclusions and monitored during 12 months of prescribed DAPT. Predictors of any nonadherence (ANA) at 6 months were analyzed by multivariable analysis, and the association between ANA at 6 or 12

Pharmacological inhibition of Polo-like kinase 1 (PLK1) by BI-2536 decreases the viability and survival of hamartin and tuberin deficient cells via induction of apoptosis and attenuation of autophagy.

The mechanistic target of rapamycin complex 1 (mTORC1) increases translation, cell size and angiogenesis, and inhibits autophagy. mTORC1 is negatively regulated by hamartin and tuberin, the protein products of the tumor suppressors TSC1 and TSC2 that are mutated in Tuberous Sclerosis Complex (TSC) and sporadic Lymphangioleiomyomatosis (LAM). Hamartin interacts with the centrosomal and mitotic kinase polo-like kinase 1 (PLK1). Hamartin and tuberin deficient cells have abnormalities in centrosome duplication, mitotic progression, and cytokinesis, suggesting that the hamartin/tuberin heterodimer

Impaired Reelin-Dab1 Signaling Contributes to Neuronal Migration Deficits of Tuberous Sclerosis Complex.

Tuberous sclerosis complex (TSC) is associated with neurodevelopmental abnormalities, including defects in neuronal migration. However, the alterations in cell signaling mechanisms critical for migration and final positioning of neurons in TSC remain unclear. Our detailed cellular analyses reveal that reduced Tsc2 in newborn neurons causes abnormalities in leading processes of migrating neurons, accompanied by significantly delayed migration. Importantly, we demonstrate that Reelin-Dab1 signaling is aberrantly regulated in TSC mouse models and in cortical tubers from TSC patients owing to enha

Incidence and clinical impact of stent fracture after the Nobori biolimus-eluting stent implantation.

BACKGROUND: Stent fracture (SF) after drug-eluting stent implantation has become an important concern. The aim of this study was to assess the incidence, predictors, and clinical impact of SF after biolimus-eluting stent. METHODS AND RESULTS: A total of 1026 patients with 1407 lesions undergoing the Nobori biolimus-eluting stent implantation and follow-up angiography within 9 months after index procedure were analyzed. SF was defined as complete or partial separation of the stent, as assessed by using plain fluoroscopy, intravascular ultrasound, or optical coherence tomography during the foll

A new era of improving progression-free survival with dual blockade in postmenopausal HR(+), HER2(-) advanced breast cancer.

Disease progression despite existing endocrine therapies remains a major challenge to the effective management of hormone-receptor-positive … lts contrast with those of the large first-line HORIZON study, wherein adding the mTOR inhibitor temsirolimus to endocrine therapy did not improve PFS. Therefore, it is unclear whether a targeted agent should only be combined with endocrine therapy to restore endocrine sensitivity or whether it may also prevent or delay resistance in hormone-sensitive advan …

Polymeric synthetic nanoparticles for the induction of antigen-specific immunological tolerance.

Current treatments to control pathological or unwanted immune responses often use broadly immunosuppressive drugs. New approaches to induce antigen-specific immunological tolerance that control both cellular and humoral immune responses are desirable. Here we describe the use of synthetic, biodegradable nanoparticles carrying either protein or peptide antigens and a tolerogenic immunomodulator, rapamycin, to induce durable and antigen-specific immune tolerance, even in the presence of potent Toll-like receptor agonists. Treatment with tolerogenic nanoparticles results in the inhibition of CD4+

Aldehyde dedydrogenase-2 plays a beneficial role in ameliorating chronic alcohol-induced hepatic steatosis and inflammation through regulation of autophagy.

BACKGROUND & AIMS: Mitochondrial aldehyde dehydrogenase (ALDH2) plays a critical role in the detoxification of the ethanol metabolite acetaldehyde. This study was designed to examine the impact of global ALDH2 overexpression on alcohol-induced hepatic steatosis. METHODS: Wild type Friend virus B (FVB) and ALDH2 transgenic mice were placed on a 4% alcohol or control diet for 12 weeks. Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin and cholesterol, hepatic triglyceride, steatosis, fat metabolism-related proteins, pro-inflammatory cytokines, glutathio

mTOR co-targeting in cetuximab resistance in head and neck cancers harboring PIK3CA and RAS mutations.

BACKGROUND: Cetuximab, a monoclonal blocking antibody against the epidermal growth factor receptor EGFR, has been approved for the treatment of squamous cell carcinomas of the head and neck (HNSCC). However, only few patients display long-term responses, prompting the search for cetuximab resistance mechanisms and new therapeutic options enhancing cetuximab effectiveness. METHODS: Cetuximab-sensitive HNSCC cells were retro-engineered to express PIK3CA and RAS oncogenes. These cells and HNSCC cells harboring endogenous PIK3CA and RAS oncogenes were xenografted into mice (n = 10 per group) and