Stabilization of Rapidly Progressive Cardiac Allograft Vasculopathy Using mTOR Inhibition After Heart Transplantation.

BACKGROUND: Inhibition of the mammalian target of rapamycin (mTor) pathway after heart transplantation has been associated with reduced progression of coronary allograft vasculopathy (CAV). The application of low-dose mTOR inhibition in the setting of modern immunosuppression, including tacrolimus, remains an area of limited exploration. METHODS: This retrospective study included patients who received heart transplantation between January 2009 and January 2019 and had baseline, 1-year and 2-3-year coronary angiography with intravascular ultrasound (IVUS). Intimal thickness in 5 segments along the left anterior descending artery was compared across imaging time points in patients who were transitioned to low-dose mTOR inhibitor (sirolimus) vs standard treatment with mycophenolate on a background of tacrolimus. Long-term adverse cardiovascular outcomes (revascularization, severe CAV, retransplant, and cardiovascular death) were also assessed. RESULTS: Among 216 patients (mean age 51.5 ± 11.9 years, 77.8% men, 80.1% white), 81 individuals (37.5%) were switched to mTOR inhibition. mTOR inhibition was associated with a reduction in intimal thickness by 0.05 mm (95% CI 0.02-0.07; P < 0.001). This reduction was driven by patients who met the criteria for rapidly progressive CAV 1-year post-transplant (0.12 mm; P = 0.016 for interaction). After a median follow-up of 8.6 (IQR 6.6-11) years, 40 patients had major adverse cardiovascular outcomes. The use of mTOR inhibitors was not significantly associated with cardiovascular outcomes (P = 0.669). CONCLUSION: Transitioning patients after heart transplantation to an immunosuppression regimen composed of low-dose mTOR inhibition and tacrolimus was associated with a lack of progression of CAV, particularly in those with rapidly progressive CAV at 1 year, but not with long-term cardiovascular outcomes.

Genome-wide analyses in Lyme borreliosis: identification of a genetic variant associated with disease susceptibility and its immunological implications.

BACKGROUND: Genetic variation underly inter-individual variation in host immune responses to infectious diseases, and may affect susceptibility or the course of signs and symptoms. METHODS: We performed genome-wide association studies in a prospective cohort of 1138 patients with physician-confirmed Lyme borreliosis (LB), the most common tick-borne disease in the Northern hemisphere caused by the bacterium Borrelia burgdorferi sensu lato. Genome-wide variants in LB patients-divided into a discovery and validation cohort-were compared to two healthy cohorts. Additionally, ex vivo monocyte-derived cytokine responses of peripheral blood mononuclear cells to several stimuli including Borrelia burgdorferi were performed in both LB patient and healthy control samples, as were stimulation experiments using mechanistic/mammalian target of rapamycin (mTOR) inhibitors. In addition, for LB patients, anti-Borrelia antibody responses were measured. Finally, in a subset of LB patients, gene expression was analysed using RNA-sequencing data from the ex vivo stimulation experiments. RESULTS: We identified a previously unknown genetic variant, rs1061632, that was associated with enhanced LB susceptibility. This polymorphism was an eQTL for KCTD20 and ETV7 genes, and its major risk allele was associated with upregulation of the mTOR pathway and cytokine responses, and lower anti-Borrelia antibody production. In addition, we replicated the recently reported SCGB1D2 locus that was suggested to have a protective effect on B. burgdorferi infection, and associated this locus with higher Borrelia burgdorferi antibody indexes and lower IL-10 responses. CONCLUSIONS: Susceptibility for LB was associated with higher anti-inflammatory responses and reduced anti-Borrelia antibody production, which in turn may negatively impact bacterial clearance. These findings provide important insights into the immunogenetic susceptibility for LB and may guide future studies on development of preventive or therapeutic measures. TRIAL REGISTRATION: The LymeProspect study was registered with the International Clinical Trials Registry Platform (NTR4998, registration date 2015-02-13).

Treatment of tuberous sclerosis complex manifestations in children with mTOR inhibitors.

PURPOSE: Tuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disorder that affects multiple organ systems. Mutations in the TSC1 and TSC2 genes result in the constitutive hyperactivation of the mammalian target of rapamycin (mTOR) pathway, contributing to the growth of benign tumors or hamartomas in various organs. Due to the implication of mTOR pathway dysregulation in the disease pathology, increasing evidence supports the use of mTOR inhibitors for treating multiple manifestations of TSC. METHODS: In this study, we conducted a retrospective analysis of clinical findings and treatment data from 38 patients diagnosed with tuberous sclerosis who were followed up in the Pediatric Oncology Clinic between 2010 and 2020. We collected information on patients' ages, genders, affected sites, familial history, imaging findings, presence of tumors, and treatments. RESULTS: Among the patients, nine individuals with TSC manifestations were treated with mTOR inhibitors. Specifically, everolimus was successfully administered to five patients with inborn cardiac rhabdomyoma causing hemodynamic impairment. In addition, two patients with refractory seizures received everolimus in combination with anti-epileptic drugs. A patient with renal angiomyolipomas larger than 3 cm was treated with everolimus, while a patient with extensive facial angiofibroma received topical sirolimus. All patients tolerated the mTOR inhibitors well, and the side effects were deemed acceptable. CONCLUSION: The utilization of mTOR inhibition in TSC is expected to become more prevalent in clinical practice, as current research is anticipated to provide a better understanding of the therapeutic roles of these treatments in TSC.

SKI-349, a Sphingosine Kinases 1/2 Inhibitor, Suppresses Cell Viability, Invasion, and AKT/mTOR Signaling Pathway, and Shows Synergistic Cytotoxic Effects with Sorafenib in Hepatocellular Carcinoma.

SKI-349 is a novel sphingosine kinases (SPHK) inhibitor with anti-tumor effects. This study aimed to assess the effect of SKI-349 on cell biological behaviors, downstream pathways, and its synergistic effect with sorafenib in hepatocellular carcinoma (HCC). HCC cell lines (Huh7 and Hep3B) were treated with SKI-349 at concentrations of 1, 2, 4, or 8 µM. Then, SPHK1/2 activity, cell viability, proliferation, apoptosis, invasion, and protein expressions of phosphorylated-protein kinase B (p-AKT), AKT, phosphorylated-mammalian target of rapamycin (p-mTOR) and mTOR were detected. Combination index values of SKI-349 (0, 1, 2, 4, or 8 µM) and sorafenib (0, 2.5, 5, 10, or 20 µM) were calculated. SKI-349 decreased the relative SPHK1 and SPHK2 activity compared with blank control in a dose-dependent manner in the Huh7 and Hep3B cell lines. Meanwhile, SKI-349 reduced cell viability, 5-ethynyl-2'-deoxyuridine (EdU) positive cells, and invasive cells, while it increased apoptotic cells compared to blank control in a dose-dependent manner in Huh7 and Hep3B cell lines. Based on the western blot assay, SKI-349 decreased the ratio of p-AKT to AKT and that of p-mTOR to mTOR compared with blank control in a dose-dependent manner in the Huh7 and Hep3B cell lines. Additionally, SKI-349 combined with sorafenib declined cell viability with concentration gradient effects compared to SKI-349 sole treatment, and they had synergistic cytotoxic effects in Huh7 and Hep3B cell lines. SKI-349 suppresses SPHK1 and SPHK2 activity, cell viability, invasion, and AKT/mTOR signaling pathway, as well as exhibits a synergistic cytotoxic effect with sorafenib in HCC.

Salidroside attenuates cerebral ischemia/reperfusion injury by regulating TSC2-induced autophagy.

Salidroside (SAL), an antioxidant derived from Rhodiola rosea, exerts neuroprotective effects in cerebral ischemia/reperfusion (I/R) injury; however, the mechanisms have not been fully elucidated. The present study established a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) and a cellular model of oxygen-glucose deprivation/reoxygenation (OGD/R) to explore the roles and mechanisms of SAL in cerebral I/R injury. The rat model of MCAO/R was established and rats were treated with different doses of SAL. The Zea-Longa scoring system and 2,3,5-triphenyltetrazolium chloride (TTC) staining showed that SAL reduced neurological deficit scores and cerebral infarct volumes in MCAO/R rats. The results of Morris water maze (MWM) test showed that SAL reduced memory impairment in MCAO/R rats. In addition, SAL significantly reduced oxidative stress and suppressed inflammatory response. Next, the OGD/R model was established with PC12 cells and treated with SAL. The results of flow cytometry and 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assays showed that SAL reduced apoptosis, enhanced cell viability and protected neuronal cells from damage by decreasing lactate dehydrogenase (LDH) activity. SAL increased the expression of TSC complex subunit 2 (TSC2), and activated the 5'-AMP-activated protein kinase (AMPK) and inhibited the mammalian target of rapamycin (mTOR) signaling pathways. It was verified that SAL alleviated cerebral I/R injury by regulating the AMPK/TSC2/mTOR pathway to induce autophagy. In conclusion, SAL reduces the inflammatory response and oxidative stress in a concentration-dependent manner, and protects against cerebral I/R injury by modulating TSC2-induced autophagy. These findings suggest SAL may prove to be a potential therapeutic agent for ischemic stroke.

Observation of a Possible Successful Treatment of DEPDC5-Related Epilepsy with mTOR Inhibitor.

The mechanistic target of the rapamycin signaling pathway serves as a central regulator of cell metabolism, growth, proliferation, and survival. In its regulation, the GTPase-activating protein activity toward Rags1 complex has an inhibitory effect. Mutations in genes encoding this complex protein are among the most common abnormalities in focal epilepsies. Within these mutations, the mutations affecting the DEPDC5 gene have been associated with different autosomal dominantly inherited epilepsy types. Due to the limited data available on mTOR inhibitor therapy in nontuberous sclerosis complex epileptic patients, here we present the clinical management of a patient with intractable epilepsy, skin hypopigmentation, and a DEPDC5 variant. The patient's phenotype is compatible with a nonlesional DEPDC5-related epileptic encephalopathy. We initiated compassionate, off-label everolimus treatment as the patient's condition continuously deteriorated. Due to bilateral pneumonia occurring at the beginning of the treatment, it was temporarily discontinued, and resumed in half the dose. Follow-up examination after 18 months showed a 90% reduction in seizure frequency with moderate improvement in attention function and nutritional status. Our case report emphasizes the importance of early genetic testing in patients with epileptic encephalopathy. Clinical consequences of mammalian target of rapamycin complex 1 (mTORC1) upregulation may be amenable to tailored treatment with mTOR inhibitors. A clinical trial on an international scale would be needed to draw conclusions.

Malignant meningioma mTOR mutated and precision medicine.

BACKGROUND: WHO grade II and III meningiomas are more invasive than grade I malignancies and determine patients' shorter overall survival. Their tendency to recur after treatment has represented an important therapeutic challenge because of the limited treatment strategies at recurrence. Angiogenesis and mechanistic target of rapamycin (mTOR) activation are two of the main features of higher grade meningiomas, determining invasiveness and tendency to relapse. While these options prove promising, available clinical data on mTOR inhibitors' efficacy are somewhat limited. CASE STUDY: We report a case of a 25-year-old female patient diagnosed with a right parasagittal occipital anaplastic meningioma (grade III WHO) in 2013. The patient underwent multiple treatments and, in 2019, a further recurrence occurred. The patient reported an mTOR mutation, and it is for this reason that the MTB approved treatment with everolimus and bevacizumab. Therapy was administered in May 2019, and partial response and prolonged disease control was obtained in November 2021, when progression took place. The patient's death occurred in March 2022. CONCLUSIONS: This case report provides evidence on the efficacy of mTOR inhibitors as a treatment option in recurrent meningiomas. Furthermore, it highlights the importance of performing a molecular analysis as a preliminary step towards targeting the mTOR pathway.

The use of mTOR inhibitors for the treatment of kaposiform hemangioendothelioma. A systematic review.

BACKGROUND: Kaposiform hemangioendothelioma (KHE) is a locally aggressive and potentially lethal vascular tumor of infancy. Current consensus recommendations include the use of vincristine and/or systemic steroids as first-line treatment. Mammalian target of rapamycin (mTOR) inhibitors represent a promising therapy for patients with KHE. The goal of our study is to critically assess the existing literature on outcomes of patients with KHE treated with mTOR inhibitors. METHODS: We conducted a literature search from 1 January 2000, to 30 April 2022. Articles reporting outcomes of patients treated with mTOR inhibitors for KHE were included. Descriptive statistics were used to describe and summarize the outcomes of the treatment. RESULTS: We included 327 patients with a mean age at diagnosis of 9.1 months (SD ± 9). Patients were treated with an mTOR inhibitor for a mean of 15.2 months (SD ± 4.1). A total of 315 (96.3%) patients had positive outcomes including improvement of the tumor size, symptoms and/or laboratory parameters in 227 (85%) and complete remission in 38 (12%). Seven (2%) patients did not respond to treatment and seven (2%) died of sepsis (4), Kasabach-Merritt phenomenon complications (1), cardiac and liver failure due to ductus arteriosus (1), or metastatic disease (1). CONCLUSION: This systematic review supports the efficacy and safety of mTOR inhibitors for KHE. Their use resulted in positive outcomes in terms of decreased symptoms, reduction in tumor size and improvement in biochemical parameters with a mortality rate of 2%. According to these findings, we suggest revised consensus treatment guidelines for KHE with mTOR inhibitors potentially considered first-line therapy.

MET Inhibits the Proliferation of EC Cells by Increasing MPA Sensitivity.

Context: The high resistance rate and high recurrence rate of progesterone only as a treatment for endometrial cancer (EC) limit its clinical application. Metformin (MET) may have antitumor ability. Combining MET and medroxyprogesterone acetate (MPA) may strengthen their inhibitory effects on proliferation of EC cells, but MET's mechanisms remain unclear. Objective: The study intended to identify the specific molecular mechanism that MET combined with MPA uses against EC progression. Design: The research team performed a controlled animal study. Setting: The study took place at Xuzhou Medical University in Xuzhou, China. Animals: The animals were16 female non-obese diabetic-severe combined immunodeficient (NOD-SCID) nude mice, about 12 to 16 g in weight. Interventions: The research team divided randomly, the mice into four groups and induced EC in all groups, four in each group: (1) The control group which received received normal saline, (2) the MPA group, which received 100 mg/kg of MPA; (3) the MET group, which received metformin at the rate of 200 mg/kg, each gavage volume was 0.1ml; (4) the MET+MPA group, which received 100 mg/kg of MPA and 200 mg/kg of MET. Outcome measures: The research team: (1) used a CCK-8 kit, an EdU assay, and a flow-cytometry assay to measure cancer-cell proliferation, count, and viability; determine the cell cycle; and measure apoptosis; (2) performed a Western blot analysis to determine the expression of the PR, CD133, pAkt, totalAkt, p-mTOR, and totalTOR antibodies; and (3) determined the size and volume of tumors in vivo and used immunohistochemical staining to determine expression of the Ki67 protein. Results: The MET+MPA group had a significantly lower number of cancer cells than the MET or MDA groups (both P < .001). That group also had significantly more stagnated cancer cells in the G0/G1 phase and significantly fewer cancer cells in the S phase or G2/M phase control, MET, or MPA groups (all P < .01). The MET+MPA group's PCNA and Ki-67 protein expression was significantly lower than that of the MET and MPA group. The EDU assay yielded similar results. Additionally, the MET+MPA group had significantly higher PR expression than that of to MET or MPA group (both P < .001). The MET and MPA groups' expression of CD133, p-Akt, and p-mTOR were significantly lower than those of the control group, while the MET+MPA group's levels were significantly lower than those of the MET and MPA groups. In-vivo experiments revealed that the MET and MPA groups did show decreased tumor size and volume. The MET+MPA group had tumor weights that were significantly lower and tumor volumes were significantly smaller than those of the MET and MPA groups (all P < .001). Immunohistochemical analysis revealed that the MET+MPA group's levels of the Ki-67 antigen were significantly lower than those of the MET and MPA groups. Conclusions: MET inhibited the proliferation of EC cells by increasing MPA-sensitivity, which was dependent on the inhibition of the CD133 expression and the Akt/mTOR pathway. In addition, if MET acts as an effective progestin sensitizer, it certainly offers promising therapeutic prospects for patients with early-stage EC or overgrown endometrium who have fertility requirements.

Catalpol Inhibits Autophagy to Ameliorate Doxorubicin-Induced Cardiotoxicity via the AKT-mTOR Pathway.

As a kind of anthracycline, doxorubicin (DOX) is commonly used as an antitumor drug, but its clinical application has been greatly hindered due to its severe cardiotoxicity. Hence, in this study, we investigated the role of catalpol (CTP) and its effect on DOX-induced cardiotoxicity.The cardiac function of mice was evaluated by assessing lactate dehydrogenase, creatine kinase isoenzyme, heart weight to body weight, and heart weight/tibia length levels. Histopathological changes were observed using hematoxylin and eosin staining, and the terminal deoxynucleotidyl transferase dUTP nick end labeling assay was used to examine myocardial apoptosis. Superoxide dismutase (SOD) activity, glutathione (GSH), and malondialdehyde (MDA) levels were measured to confirm the changes in oxidative stress. Western blotting showed the levels of autophagy- and pathway-related proteins. Expression of autophagy marker LC3 was examined using immunofluorescence staining.CTP alleviated DOX-induced cardiac damage in mice. We further observed upregulated SOD and GSH levels, and downregulated MDA level after the CTP treatment in DOX-treated mice, indicating the protective role of CTP against oxidative injury. DOX-induced myocardial apoptosis was also inhibited by CTP treatment in mice. In addition, CTP decreased the levels of Beclin1 and LC3II/LC3I, increased the levels of P62, and activated the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway in DOX-treated mice.CTP ameliorated DOX-induced cardiotoxicity by inhibiting oxidative stress, myocardial apoptosis, and autophagy via the AKT-mTOR pathway.

mTOR-therapy and targeted treatment opportunities in mTOR-related epilepsies associated with cortical malformations.

Dysregulation of the mTOR pathway is now well documented in several neurodevelopmental disorders associated with epilepsy. Mutations of mTOR pathway genes are involved in tuberous sclerosis complex (TSC) as well as in a range of cortical malformations from hemimegalencephaly (HME) to type II focal cortical dysplasia (FCD II), leading to the concept of "mTORopathies" (mTOR pathway-related malformations). This suggests that mTOR inhibitors (notably rapamycin (sirolimus), and everolimus) could be used as antiseizure medication. In this review, we provide an overview of pharmacological treatments targeting the mTOR pathway for epilepsy based on lectures from the ILAE French Chapter meeting in October 2022 in Grenoble. There is strong preclinical evidence for the antiseizure effects of mTOR inhibitors in TSC and cortical malformation mouse models. There are also open studies on the antiseizure effects of mTOR inhibitors, as well as one phase III study showing the antiseizure effect of everolimus in TSC patients. Finally, we discuss to which extent mTOR inhibitors might have properties beyond the antiseizure effect on associated neuropsychiatric comorbidities. We also discuss a new way of treatment on the mTOR pathways.

Halofuginone inhibits cell proliferation and AKT/mTORC1 signaling in uterine leiomyoma cells.

The present study aimed to explore the effects of antifibrotic agent halofuginone on uterine leiomyomas (ULs) cells. The survival of the uterine smooth muscle (UtSMC) cells and UL ELT3 cells were measured. Flow cytometry was used to assess the cell cycle distribution and apoptosis. Effects of halofuginone on the state of AKT/mTOR pathway were evaluated. Xenograft animal model was applied to explore the effects of halofuginone in vivo. Halofuginone inhibited the proliferation of ELT3 cells dose-dependently without obvious influence on UtSMC cells. Halofuginone suppressed cell cycle progression and promoted apoptosis of ELT3 cells dose-dependently. Also, p-AKT/AKT and p-p70S6/p70S6 were significantly lowered after treatment with 20 nM halofuginone. Additionally, halofuginone reduced ELT3 tumor growth in xenograft tumor animal model. The present study illustrates that halofuginone inhibits cell proliferation of ULs with low side effects on normal smooth muscle cells, and AKT/mTOR signaling pathway was inactivated meanwhile.

Controlled-Level EVERolimus in Acute Coronary Syndrome (CLEVER-ACS) - A phase II, randomized, double-blind, multi-center, placebo-controlled trial.

BACKGROUND: Activation of inflammatory pathways during acute myocardial infarction contributes to infarct size and left ventricular (LV) remodeling. The present prospective randomized clinical trial was designed to test the efficacy and safety of broad-spectrum anti-inflammatory therapy with a mammalian target of rapamycin (mTOR) inhibitor to reduce infarct size. DESIGN: Controlled-Level EVERolimus in Acute Coronary Syndrome (CLEVER-ACS, clinicaltrials.gov NCT01529554) is a phase II randomized, double-blind, multi-center, placebo-controlled trial on the effects of a 5-day course of oral everolimus on infarct size, LV remodeling, and inflammation in patients with acute ST-elevation myocardial infarction (STEMI). Within 5 days of successful primary percutaneous coronary intervention (pPCI), patients are randomly assigned to everolimus (first 3 days: 7.5 mg every day; days 4 and 5: 5.0 mg every day) or placebo, respectively. The primary efficacy outcome is the change from baseline (defined as 12 hours to 5 days after pPCI) to 30-day follow-up in myocardial infarct size as measured by cardiac magnetic resonance imaging (CMRI). Secondary endpoints comprise corresponding changes in cardiac and inflammatory biomarkers as well as microvascular obstruction and LV volumes assessed by CMRI. Clinical events, laboratory parameters, and blood cell counts are reported as safety endpoints at 30 days. CONCLUSION: The CLEVER-ACS trial tests the hypothesis whether mTOR inhibition using everolimus at the time of an acute STEMI affects LV infarct size following successful pPCI.

Nitazoxanide inhibits osteosarcoma cells growth and metastasis by suppressing AKT/mTOR and Wnt/ß-catenin signaling pathways.

Osteosarcoma (OS) is the most prevalent malignant bone tumor with poor prognosis. Developing new drugs for the chemotherapy of OS has been a focal point and a major obstacle of OS treatment. Nitazoxanide (NTZ), a conventional anti-parasitic agent, has got increasingly noticed because of its favorable antitumor potential. Herein, we investigated the effect of NTZ on human OS cells in vitro and in vivo. The results obtained in vitro showed that NTZ inhibited the proliferation, migration and invasion, arrested cell cycle at G1 phase, while induced apoptosis of OS cells. Mechanistically, NTZ suppressed the activity of AKT/mTOR and Wnt/ß-catenin signaling pathways of OS cells. Consistent with the results in vitro, orthotopic implantation model of 143B OS cells further confirmed that NTZ inhibited OS cells growth and lung metastasis in vivo. Notably, NTZ caused no apparent damage to normal cells/tissues. In conclusion, NTZ may inhibit tumor growth and metastasis of human OS cells through suppressing AKT/mTOR and Wnt/ß-catenin signaling pathways.

Hydra-Elastin-like Polypeptides Increase Rapamycin Potency When Targeting Cell Surface GRP78.

Rapalogues are powerful therapeutic modalities for breast cancer; however, they suffer from low solubility and dose-limiting side effects. To overcome these challenges, we developed a long-circulating multiheaded drug carrier called 5FA, which contains rapamycin-binding domains linked with elastin-like polypeptides (ELPs). To target these "Hydra-ELPs" toward breast cancer, we here linked 5FA with four distinct peptides which are reported to engage the cell surface form of the 78 kDa glucose-regulated protein (csGRP78). To determine if these peptides affected the carrier solubility, this library was characterized by light scattering and mass spectrometry. To guide in vitro selection of the most potent functional carrier for rapamycin, its uptake and inhibition of mTORC1 were monitored in a ductal breast cancer model (BT474). Using flow cytometry to track cellular association, it was found that only the targeted carriers enhanced cellular uptake and were susceptible to proteolysis by SubA, which specifically targets csGRP78. The functional inhibition of mTOR was monitored by Western blot for pS6K, whereby the best carrier L-5FA reduced mTOR activity by 3-fold compared to 5FA or free rapamycin. L-5FA was further visualized using super-resolution confocal laser scanning microscopy, which revealed that targeting increased exposure to the carrier by ∼8-fold. This study demonstrates how peptide ligands for GRP78, such as the L peptide (RLLDTNRPLLPY), may be incorporated into protein-based drug carriers to enhance targeting.

RBM8A Depletion Decreases the Cisplatin Resistance and Represses the Proliferation and Metastasis of Breast Cancer Cells via AKT/mTOR Pathway.

Background: Breast cancer (BC) is the most prevalent malignancy in women. This study is aimed to explore the role and regulatory mechanism of RNA-binding motif protein 8A (RBM8A) in BC. Methods: We detected the expression of RBM8A in BC tissues and cell lines (MCF-7, MDA-MB-231, and MDA-MB-436), and explored the correlation of RBM8A expression with clinicopathological features in patients. The function of RBM8A deficiency in MCF-7 and MDA-MB-231 cells was determined using MTT, wound healing, and transwell assay. The effect of RBM8A suppression on the cisplatin (DDP) resistance in MCF-7 and MDA-MB-231 cells was also evaluated. Besides, western blotting was used to examine AKT/mTOR pathway-related proteins. The mouse model was constructed to confirm the effect of RBM8A on tumor growth. Results: The expression of RBM8A was elevated in BC tissues and cell lines. RBM8A silencing restrained the malignant behaviors of MCF-7 and MDA-MB-231 cells, including viability, migration, and invasion, while promoting apoptosis. Silencing of RBM8A overcame resistance to DDP in MCF-7 and MDA-MB-231 cells. Furthermore, RBM8A suppression restrained the activation of the AKT/mTOR pathway in both MCF-7 and MDA-MB-231 cells. Feedback experiments revealed that SC79 treatment reversed the reduction effects of RBM8A knockdown on viability, DDP resistance, migration, and invasion of MDA-MB-231 cells. Moreover, the silencing of RBM8A inhibited the growth of tumor xenograft in vivo. Conclusions: RBM8A knockdown may reduce DDP resistance in BC to repress the development of BC via the AKT/mTOR pathway, suggesting that RBM8A may serve as a new therapeutic target in BC.

Modulation of PTZ-induced convulsions in rats using topiramate alone or combined with low dose gamma irradiation: involving AKT/m-TOR pathway.

The current study evaluates the anticonvulsant effect low dose whole body gamma irradiation (LDR) alone or combined with topiramate against pentylenetetrazole (PTZ)-induced convulsions. Male Wister rats received either saline or PTZ (75 mg/kg i.p.). The other three groups were pretreated with single low dose radiation (0.5 Gy), topiramate (50 mg/kg, p.o., seven days) and TPM with LDR respectively before PTZ injection. Racine' score, latency, and duration of the convulsions were assessed. Glutamate and GABA were measured. AKT/m-TOR signaling pathway including AKT (protein kinase B), mammalian target of rapamycin (m-TOR), protein S6, and caspase 3 were also assessed. Measurements of markers of oxidative stress including malondialdehyde (MDA), glutathione (GSH), and nitric oxide (NO) were carried out. Histological examinations of hippocampi were done. PTZ produced behavioral changes (high Racine score, short latency, and long duration). It elevated MDA and NO contents, while reduced GSH content. TPM treatment alone or combined with LDR ameliorated the PTZ-induced convulsions and caused significant improvement in behavioral changes, brain mediators, m-TOR pathway, oxidative stress, and histological pictures in hippocampal regions. Histopathological examinations of the normal group showed normal structure with intact cells, while PTZ-treated rats exhibited necrosis, pyknosis, and atrophy of pyramidal cells. The histological findings corroborated with the amendment of biochemical parameters. The positive effects of LDR could offer a possible contributor in management of convulsions due to modulation of AkT/m-TOR signaling pathway, reduction of oxidative stress and modulation of brain amino acids. LDR improved the oxidative stress side effects of topiramate.

miRNA Expression Associated with HbF in Saudi Sickle Cell Anemia.

Background and Objectives: Sickle cell anemia (SCA) is a hereditary monogenic disease due to a single ß-globin gene mutation that codes for the production of sickle hemoglobin. Its phenotype is modulated by fetal hemoglobin (HbF), a product of γ-globin genes. Exploring the molecules that regulate γ-globin genes at both transcriptional and translational levels, including microRNA (miRNA), might help identify alternative therapeutic targets. Materials and Methods: Using next-generation sequencing we identified pre-miRNAs and mature miRNA expression signatures associated with different HbF levels in patients homozygous for the sickle hemoglobin gene. The involvement of identified miRNAs in potential SCD-related pathways was investigated with the DIANA TOOL and miRWalk 2.0 database. Results: miR-184 were most highly upregulated in reticulocytes. miR-3609 and miR-483-5p were most highly downregulated in sickle cell anemia with high HbF. miR-370-3p that regulates LIN28A, and miR-451a which is effective in modulating α- and ß- globin levels were also significantly upregulated. miRNA targeted gene pathway interaction identified BCL7A, BCL2L1, LIN28A, KLF6, GATA6, solute carrier family genes and ZNF genes associated with erythropoiesis, cell cycle regulation, glycosphingolipid biosynthesis, cAMP, cGMP-PKG, mTOR, MAPK and PI3K-AKT signaling pathways and cancer pathways. Conclusions: miRNA signatures and their target genes identified novel miRNAs that could regulate fetal hemoglobin production and might be exploited therapeutically.

Chrysophanol-Induced Autophagy Disrupts Apoptosis via the PI3K/Akt/mTOR Pathway in Oral Squamous Cell Carcinoma Cells.

Background and Objectives: Natural products are necessary sources for drug discovery and have contributed to cancer chemotherapy over the past few decades. Furthermore, substances derived from plants have fewer side effects. Chrysophanol is an anthraquinone derivative that is isolated from rhubarb. Although the anticancer effect of chrysophanol on several cancer cells has been reported, studies on the antitumor effect of chrysophanol on oral squamous-cell carcinoma (OSCC) cells have yet to be elucidated. Therefore, in this study, we investigated the anticancer effect of chrysophanol on OSCC cells (CAL-27 and Ca9-22) via apoptosis and autophagy, among the cell death pathways. Results: It was found that chrysophanol inhibited the growth and viability of CAL-27 and Ca9-22 and induced apoptosis through the intrinsic pathway. It was also found that chrysophanol activates autophagy-related factors (ATG5, beclin-1, and P62/SQSTM1) and LC3B conversion. That is, chrysophanol activated both apoptosis and autophagy. Here, we focused on the roles of chrysophanol-induced apoptosis and the autophagy pathway. When the autophagy inhibitor 3-MA and PI3K/Akt inhibitor were used to inhibit the autophagy induced by chrysophanol, it was confirmed that the rate of apoptosis significantly increased. Therefore, we confirmed that chrysophanol induces apoptosis and autophagy at the same time, and the induced autophagy plays a role in interfering with apoptosis processes. Conclusions: Therefore, the potential of chrysophanol as an excellent anticancer agent in OSCC was confirmed via this study. Furthermore, the combined treatment of drugs that can inhibit chrysophanol-induced autophagy is expected to have a tremendous synergistic effect in overcoming oral cancer.

RETROPERITONEAL PERIVASCULAR EPITHELIOID CELL NEOPLASM (PECOMA) RESPONSE TO MTOR KINASE INHIBITION. A CASE REPORT WITH LITERATURE REVIEW.

Perivascular epithelioid cell tumors (PEComas) are a very rare group of neoplasms and were first reported in 1996. These tumors represent a family of mesenchymal neoplasms, related through activation of the mammalian target of rapamycin (mTOR) inhibitor signaling pathway. The objective of this case report is to demonstrate significant regression of the tumor after neoadjuvant treatment with an oral mTOR inhibitor, following surgical removal of the mass to avoid a multiorgan resection. We present a case of a 27-year-old female with retroperitoneal PEComa and evaluated the tumor with MRI and integrated 18F-FDG-PET/CT scans at presentation and serially during treatment with everolimus. After 6 months of treatment with everolimus the tumor showed a substantial size reduction. Therefore, a multiorgan resection could be omitted. The patient has not demonstrated any disease recurrence after nearly 2 years of follow-up. PEComas are tumors with unpredictable behavior. Our report indicates that treatment of PEComas with everolimus may achieve a significant clinical response. As indicated by our case and past reports, mTOR inhibitors may be one of the best treatment options for this disease.