TOR, the Gateway to Cellular Metabolism, Cell Growth, and Disease.

Michael N. Hall is this year's recipient of the Lasker Basic Medical Research Award for the identification of the target of rapamycin, TOR. TOR is a master regulator of the cell's growth and metabolic state, and its dysregulation contributes to a variety of diseases, including diabetes, obesity, neurodegenerative disorders, aging, and cancer, making the TOR pathway an attractive therapeutic target.

An Amazing Turn of Events.

How the master regulator of cell growth, TOR, came to be identified and understood, from the perspective of its discoverer, Michael N. Hall.

GNA14 and GNAQ somatic mutations cause spinal and intracranial extra-axial cavernous hemangiomas.

Extra-axial cavernous hemangiomas (ECHs) are complex vascular lesions mainly found in the spine and cavernous sinus. Their removal poses significant risk due to their vascularity and diffuse nature, and their genetic underpinnings remain incompletely understood. Our approach involved genetic analyses on 31 tissue samples of ECHs employing whole-exome sequencing and targeted deep sequencing. We explored downstream signaling pathways, gene expression changes, and resultant phenotypic shifts induced by these mutations, both in vitro and in vivo. In our cohort, 77.4% of samples had somatic missense variants in GNA14, GNAQ, or GJA4. Transcriptomic analysis highlighted significant pathway upregulation, with the GNAQ c.626A>G (p.Gln209Arg) mutation elevating PI3K-AKT-mTOR and angiogenesis-related pathways, while GNA14 c.614A>T (p.Gln205Leu) mutation led to MAPK and angiogenesis-related pathway upregulation. Using a mouse xenograft model, we observed enlarged vessels from these mutations. Additionally, we initiated rapamycin treatment in a 14-year-old individual harboring the GNAQ c.626A>G (p.Gln209Arg) variant, resulting in gradual regression of cutaneous cavernous hemangiomas and improved motor strength, with minimal side effects. Understanding these mutations and their pathways provides a foundation for developing therapies for ECHs resistant to current therapies. Indeed, the administration of rapamycin in an individual within this study highlights the promise of targeted treatments in treating these complex lesions.

Dominant-activating germline mutations in the gene encoding the PI(3)K catalytic subunit p110δ result in T cell senescence and human immunodeficiency.

The p110δ subunit of phosphatidylinositol-3-OH kinase (PI(3)K) is selectively expressed in leukocytes and is critical for lymphocyte biology. Here we report fourteen patients from seven families who were heterozygous for three different germline, gain-of-function mutations in PIK3CD (which encodes p110δ). These patients presented with sinopulmonary infections, lymphadenopathy, nodular lymphoid hyperplasia and viremia due to cytomegalovirus (CMV) and/or Epstein-Barr virus (EBV). Strikingly, they had a substantial deficiency in naive T cells but an over-representation of senescent effector T cells. In vitro, T cells from patients exhibited increased phosphorylation of the kinase Akt and hyperactivation of the metabolic checkpoint kinase mTOR, enhanced glucose uptake and terminal effector differentiation. Notably, treatment with rapamycin to inhibit mTOR activity in vivo partially restored the abundance of naive T cells, largely 'rescued' the in vitro T cell defects and improved the clinical course.

Drug-coated balloon angioplasty with rescue stenting versus intended stenting for the treatment of patients with de novo coronary artery lesions (REC-CAGEFREE I): an open-label, randomised, non-inferiority trial.

BACKGROUND: The long-term impact of drug-coated balloon (DCB) angioplasty for the treatment of patients with de novo coronary artery lesions remains uncertain. We aimed to assess the non-inferiority of DCB angioplasty with rescue stenting to intended drug-eluting stent (DES) deployment for patients with de novo, non-complex coronary artery lesions. METHODS: REC-CAGEFREE I was an open-label, randomised, non-inferiority trial conducted at 43 sites in China. After successful lesion pre-dilatation, patients aged 18 years or older with de novo, non-complex coronary artery disease (irrespective of target vessel diameter) and an indication for percutaneous coronary intervention were randomly assigned (1:1), via a web-based centralised system with block randomisation (block size of two, four, or six) and stratified by site, to paclitaxel-coated balloon angioplasty with the option of rescue stenting due to an unsatisfactory result (DCB group) or intended deployment of second-generation thin-strut sirolimus-eluting stents (DES group). The primary outcome was the device-oriented composite endpoint (DoCE; including cardiovascular death, target vessel myocardial infarction, and clinically and physiologically indicated target lesion revascularisation) assessed at 24 months in the intention-to-treat (ITT) population (ie, all participants randomly assigned to treatment). Non-inferiority was established if the upper limit of the one-sided 95% CI for the absolute risk difference was smaller than 2·68%. Safety was assessed in the ITT population. This study is registered with ClinicalTrials.gov, NCT04561739. It is closed to accrual and extended follow-up is ongoing. FINDINGS: Between Feb 5, 2021, and May 1, 2022, 2272 patients were randomly assigned to the DCB group (1133 [50%]) or the DES group (1139 [50%]). Median age at the time of randomisation was 62 years (IQR 54-69), 1574 (69·3%) of 2272 were male, 698 (30·7%) were female, and all patients were of Chinese ethnicity. 106 (9·4%) of 1133 patients in the DCB group received rescue DES after unsatisfactory DCB angioplasty. As of data cutoff (May 1, 2024), median follow-up was 734 days (IQR 731-739). At 24 months, the DoCE occurred in 72 (6·4%) of 1133 patients in the DCB group and 38 (3·4%) of 1139 in the DES group, with a risk difference of 3·04% in the cumulative event rate (upper boundary of the one-sided 95% CI 4·52; pnon-inferiority=0·65; two-sided 95% CI 1·27-4·81; p=0·0008); the criterion for non-inferiority was not met. During intervention, no acute vessel closures occurred in the DCB group and one (0·1%) of 1139 patients in the DES group had acute vessel closure. Periprocedural myocardial infarction occurred in ten (0·9%) of 1133 patients in the DCB group and nine (0·8%) in the DES group. INTERPRETATION: In patients with de novo, non-complex coronary artery disease, irrespective of vessel diameter, a strategy of DCB angioplasty with rescue stenting did not achieve non-inferiority compared with the intended DES implantation in terms of the DoCE at 2 years, which indicates that DES should remain the preferred treatment for this patient population. FUNDING: Xijing Hospital and Shenqi Medical. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

mTOR inhibition attenuates cTfh cell dysregulation and chronic T-cell activation in multilineage immune cytopenias.

mTOR inhibitors such as sirolimus are increasingly used in the management of multilineage immune cytopenia (m-IC) in children. Although sirolimus is effective in improving IC, it is unclear how sirolimus affects the broader immune dysregulation associated with m-IC. We profiled T- and B-cell subsets longitudinally and measured cytokines and chemokines before and after sirolimus treatment. Eleven of the 12 patients with m-IC who tolerated sirolimus were followed for a median duration of 17 months. All patients had an improvement in IC, and sirolimus therapy did not result in significant decreases in T-, B- and NK-cell numbers. However, the expansion and activation of circulating T follicular helper and the Th1 bias noted before the initiation of sirolimus were significantly decreased. Features of chronic T-cell activation and exhaustion within effector memory compartments of CD4+ and CD8+ T cells decreased with sirolimus therapy. Corresponding to these changes, plasma levels of CXCL9 and CXCL10 also decreased. Interestingly, no significant improvement in the proportion of class-switched memory B cells or frequencies of CD4+ naive T cells were noted. Longer follow-up and additional studies are needed to validate these findings and evaluate the effect of sirolimus on B-cell maturation.

Sulfated Polysaccharide-Based Nanocarrier Drives Microenvironment-Mediated Cerebral Neurovascular Remodeling for Ischemic Stroke Treatment.

Stroke is a leading cause of global mortality and severe disability. However, current strategies used for treating ischemic stroke lack specific targeting capabilities, exhibit poor immune escape ability, and have limited drug release control. Herein, we developed an ROS-responsive nanocarrier for targeted delivery of the neuroprotective agent rapamycin (RAPA) to mitigate ischemic brain damage. The nanocarrier consisted of a sulfated chitosan (SCS) polymer core modified with a ROS-responsive boronic ester enveloped by a red blood cell membrane shell incorporating a stroke homing peptide. When encountering high levels of intracellular ROS in ischemic brain tissues, the release of SCS combined with RAPA from nanoparticle disintegration facilitates effective microglia polarization and, in turn, maintains blood-brain barrier integrity, reduces cerebral infarction, and promotes cerebral neurovascular remodeling in a mouse stroke model involving transient middle cerebral artery occlusion (tMCAO). This work offers a promising strategy to treat ischemic stroke therapy.

Irinotecan and temozolomide in combination with dasatinib and rapamycin versus irinotecan and temozolomide for patients with relapsed or refractory neuroblastoma (RIST-rNB-2011): a multicentre, open-label, randomised, controlled, phase 2 trial.

BACKGROUND: Neuroblastoma is the most common extracranial solid tumour in children. Relapsed or refractory neuroblastoma is associated with a poor outcome. We assessed the combination of irinotecan-temozolomide and dasatinib-rapamycin (RIST) in patients with relapsed or refractory neuroblastoma. METHODS: The multicentre, open-label, randomised, controlled, phase 2, RIST-rNB-2011 trial recruited from 40 paediatric oncology centres in Germany and Austria. Patients aged 1-25 years with high-risk relapsed (defined as recurrence of all stage IV and MYCN amplification stages, after response to treatment) or refractory (progressive disease during primary treatment) neuroblastoma, with Lansky and Karnofsky performance status at least 50%, were assigned (1:1) to RIST (RIST group) or irinotecan-temozolomide (control group) by block randomisation, stratified by MYCN status. We compared RIST (oral rapamycin [loading 3 mg/m2 on day 1, maintenance 1 mg/m2 on days 2-4] and oral dasatinib [2 mg/kg per day] for 4 days with 3 days off, followed by intravenous irinotecan [50 mg/m2 per day] and oral temozolomide [150 mg/m2 per day] for 5 days with 2 days off; one course each of rapamycin-dasatinib and irinotecan-temozolomide for four cycles over 8 weeks, then two courses of rapamycin-dasatinib followed by one course of irinotecan-temozolomide for 12 weeks) with irinotecan-temozolomide alone (with identical dosing as experimental group). The primary endpoint of progression-free survival was analysed in all eligible patients who received at least one course of therapy. The safety population consisted of all patients who received at least one course of therapy and had at least one post-baseline safety assessment. This trial is registered at ClinicalTrials.gov, NCT01467986, and is closed to accrual. FINDINGS: Between Aug 26, 2013, and Sept 21, 2020, 129 patients were randomly assigned to the RIST group (n=63) or control group (n=66). Median age was 5·4 years (IQR 3·7-8·1). 124 patients (78 [63%] male and 46 [37%] female) were included in the efficacy analysis. At a median follow-up of 72 months (IQR 31-88), the median progression-free survival was 11 months (95% CI 7-17) in the RIST group and 5 months (2-8) in the control group (hazard ratio 0·62, one-sided 90% CI 0·81; p=0·019). Median progression-free survival in patients with amplified MYCN (n=48) was 6 months (95% CI 4-24) in the RIST group versus 2 months (2-5) in the control group (HR 0·45 [95% CI 0·24-0·84], p=0·012); median progression-free survival in patients without amplified MYCN (n=76) was 14 months (95% CI 9-7) in the RIST group versus 8 months (4-15) in the control group (HR 0·84 [95% CI 0·51-1·38], p=0·49). The most common grade 3 or worse adverse events were neutropenia (54 [81%] of 67 patients given RIST vs 49 [82%] of 60 patients given control), thrombocytopenia (45 [67%] vs 41 [68%]), and anaemia (39 [58%] vs 38 [63%]). Nine serious treatment-related adverse events were reported (five patients given control and four patients given RIST). There were no treatment-related deaths in the control group and one in the RIST group (multiorgan failure). INTERPRETATION: RIST-rNB-2011 demonstrated that targeting of MYCN-amplified relapsed or refractory neuroblastoma with a pathway-directed metronomic combination of a multkinase inhibitor and an mTOR inhibitor can improve progression-free survival and overall survival. This exclusive efficacy in MYCN-amplified, relapsed neuroblastoma warrants further investigation in the first-line setting. FUNDING: Deutsche Krebshilfe.

Addition of temsirolimus to chemotherapy in children, adolescents, and young adults with intermediate-risk rhabdomyosarcoma (ARST1431): a randomised, open-label, phase 3 trial from the Children's Oncology Group.

BACKGROUND: The Children's Oncology Group defines intermediate-risk rhabdomyosarcoma as unresected FOXO1 fusion-negative disease arising at an unfavourable site or non-metastatic FOXO1 fusion-positive disease. Temsirolimus in combination with chemotherapy has shown promising activity in patients with relapsed or refractory rhabdomyosarcoma. We aimed to compare event-free survival in patients with intermediate-risk rhabdomyosarcoma treated with vincristine, actinomycin, and cyclophosphamide alternating with vincristine and irinotecan (VAC/VI) combined with temsirolimus followed by maintenance therapy versus VAC/VI alone with maintenance therapy. METHODS: ARST1431 was a randomised, open-label, phase 3 trial conducted across 210 institutions in Australia, Canada, New Zealand, and the USA. Eligible patients were those aged 40 years or younger with non-metastatic FOXO1-positive rhabdomyosarcoma or unresected FOXO1-negative rhabdomyosarcoma disease from unfavourable sites. Two other groups of patients were also eligible: those who had FOXO1-negative disease at a favourable site (excluding orbit) that was unresected; and those who were aged younger than 10 years with stage IV FOXO1-negative disease with distant metastases. Eligible patients had to have a Lansky performance status score of 50 or higher if 16 years or younger and a Karnofsky performance status score of 50 or higher if older than 16 years; all patients were previously untreated. Patients were randomised (1:1) in blocks of four and stratified by histology, stage, and group. Patients received intravenous VAC/VI chemotherapy with a cyclophosphamide dose of 1·2 g/m2 per dose per cycle with or without a reducing dose of intravenous weekly temsirolimus starting at 15 mg/m2 or 0·5 mg/kg per dose for those who weighed less than 10 kg. The total duration of therapy was 42 weeks followed by 6 months of maintenance therapy with oral cyclophosphamide plus intravenous vinorelbine for all patients. Temsirolimus was withheld during radiotherapy and for 2 weeks before any major surgical procedure. The primary endpoint was 3-year event-free survival. Data were analysed with a revised intention-to-treat approach. The study is registered with ClinicalTrials.gov (NCT02567435) and is complete. FINDINGS: Between May 23, 2016, and Jan 1, 2022, 325 patients were enrolled. In 297 evaluable patients (148 assigned to VAC/VI alone and 149 assigned to VAC/VI with temsirolimus), the median age was 6·3 years (IQR 3·0-11·3); 33 (11%) patients were aged 18 years or older; 179 (60%) of 297 were male. 113 (77%) of 148 patients were FOXO1 negative in the VAC/VI group, and 108 (73%) of 149 were FOXO1 negative in the VAC/VI with temsirolimus group. With a median follow-up of 3·6 years (IQR 2·8-4·5), 3-year event-free survival did not differ significantly between the two groups (64·8% [95% CI 55·5-74·1] in the VAC/VI group vs 66·8% [57·5-76·2] in the VAC/VI plus temsirolimus group (hazard ratio 0·86 [95% CI 0·58-1·26]; log-rank p=0·44). The most common grade 3-4 adverse events were anaemia (62 events in 60 [41%] of 148 patients in the VAC/VI group vs 89 events in 87 [58%] of 149 patients in the VAC/VI with temsirolimus group), lymphopenia (83 events in 65 [44%] vs 99 events in 71 [48%]), neutropenia (160 events in 99 [67%] vs 164 events in 105 [70%]), and leukopenia (121 events in 86 [58%] vs 132 events in 93 [62%]). There was one treatment-related death in the VAC/VI with temsirolimus group, categorised as not otherwise specified. INTERPRETATION: Addition of temsirolimus to VAC/VI did not improve event-free survival in patients with intermediate-risk rhabdomyosarcoma defined by their FOXO1 translocation status and clinical factors. Novel biology-based strategies are needed to improve outcomes in this population. FUNDING: The Children's Oncology Group (supported by the US National Cancer Institute, US National Institutes of Health).

Prednisolone and rapamycin reduce the plasma cell gene signature and may improve AAV gene therapy in cynomolgus macaques.

Adeno-associated virus (AAV) vector gene therapy is a promising approach to treat rare genetic diseases; however, an ongoing challenge is how to best modulate host immunity to improve transduction efficiency and therapeutic outcomes. This report presents two studies characterizing multiple prophylactic immunosuppression regimens in male cynomolgus macaques receiving an AAVrh10 gene therapy vector expressing human coagulation factor VIII (hFVIII). In study 1, no immunosuppression was compared with prednisolone, rapamycin (or sirolimus), rapamycin and cyclosporin A in combination, and cyclosporin A and azathioprine in combination. Prednisolone alone demonstrated higher mean peripheral blood hFVIII expression; however, this was not sustained upon taper. Anti-capsid and anti-hFVIII antibody responses were robust, and vector genomes and transgene mRNA levels were similar to no immunosuppression at necropsy. Study 2 compared no immunosuppression with prednisolone alone or in combination with rapamycin or methotrexate. The prednisolone/rapamycin group demonstrated an increase in mean hFVIII expression and a mean delay in anti-capsid IgG development until after rapamycin taper. Additionally, a significant reduction in the plasma cell gene signature was observed with prednisolone/rapamycin, suggesting that rapamycin's tolerogenic effects may include plasma cell differentiation blockade. Immunosuppression with prednisolone and rapamycin in combination could improve therapeutic outcomes in AAV vector gene therapy.

The mitochondriogenic but not the immunosuppressant effects of mTOR inhibitors prompt neuroprotection and delay disease evolution in a mouse model of progressive multiple sclerosis.

INTRODUCTION: Purportedly, the progression of multiple sclerosis (MS) occurs when neurodegenerative processes due to derangement of axonal bioenergetics take over the autoimmune response. However, a clear picture of the causative interrelationship between autoimmunity and axonal mitochondrial dysfunction in progressive MS (PMS) pathogenesis waits to be provided. METHODS: In the present study, by adopting the NOD mouse model of PMS, we compared the pharmacological effects of the immunosuppressants dexamethasone and fingolimod with those of mTOR inhibitors rapamycin and everolimus that, in addition to immunosuppression, also regulate mitochondrial functioning. Female Non-Obese Diabetic (NOD) mice were immunized with MOG35-55 and treated with drugs to evaluate functional, immune and mitochondrial parameters during disease evolution. RESULTS: We found that dexamethasone and fingolimod did not affect the pattern of progression as well as survival. Conversely, mTOR inhibitors rapamycin and everolimus delayed disease progression and robustly extended survival of immunized mice. The same effects were obtained when treatment was delayed by 30 days after immunization. Remarkably, dexamethasone and fingolimod prompted the same degree of immunosuppression of rapamycin within both spleen and spinal cord of mice. However, only rapamycin prompted mitochondriogenesis by increasing mitochondrial content, and expression of several mitochondrial respiratory complex subunits, thereby preventing mtDNA reduction in the spinal cords of immunized mice. These pharmacodynamic effects were not reproduced in healthy NOD mice, suggesting a disease context-dependent pharmacodynamic effect. DISCUSSION: Data corroborate the key role of mitochondriogenesis to treatment of MS progression, and for the first time disclose the translational potential of mTOR inhibitors in PMS therapy.

Long-term outcomes with biodegradable polymer sirolimus-eluting stents versus durable polymer everolimus-eluting stents in ST-segment elevation myocardial infarction: 5-year follow-up of the BIOSTEMI randomised superiority trial.

BACKGROUND: Biodegradable polymer sirolimus-eluting stents improve early stent-related clinical outcomes compared to durable polymer everolimus-eluting stents in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention. The long-term advantages of biodegradable polymer sirolimus-eluting stents after complete degradation of its polymer coating in patients with STEMI remains however uncertain. METHODS: BIOSTEMI Extended Survival (BIOSTEMI ES) was an investigator-initiated, follow-up extension study of the BIOSTEMI prospective, multicentre, single-blind, randomised superiority trial that compared biodegradable polymer sirolimus-eluting stents with durable polymer everolimus-eluting stents in patients with STEMI undergoing primary percutaneous coronary intervention at ten hospitals in Switzerland. All individuals who had provided written informed consent for participation in the BIOSTEMI trial were eligible for this follow-up study. The primary endpoint was target lesion failure, defined as a composite of cardiac death, target vessel myocardial re-infarction, or clinically indicated target lesion revascularisation, at 5 years. Superiority of biodegradable polymer sirolimus-eluting stents over durable polymer everolimus-eluting stents was declared if the Bayesian posterior probability for a rate ratio (RR) of less than 1 was greater than 0·975. Analyses were performed according to the intention-to-treat principle. The study was registered with ClinicalTrials.gov, NCT05484310. FINDINGS: Between April 26, 2016, and March 9, 2018, 1300 patients with STEMI (1622 lesions) were randomly allocated in a 1:1 ratio to treatment with biodegradable polymer sirolimus-eluting stents (649 patients, 816 lesions) or durable polymer everolimus-eluting stents (651 patients, 806 lesions). At 5 years, the primary composite endpoint of target lesion failure occurred in 50 (8%) patients treated with biodegradable polymer sirolimus-eluting stents and in 72 (11%) patients treated with durable polymer everolimus-eluting stents (difference of -3%; RR 0·70, 95% Bayesian credible interval 0·51-0·95; Bayesian posterior probability for superiority 0·988). INTERPRETATION: In patients undergoing primary percutaneous coronary intervention for STEMI, biodegradable polymer sirolimus-eluting stents were superior to durable polymer everolimus-eluting stents with respect to target lesion failure at 5 years of follow-up. The difference was driven by a numerically lower risk for ischaemia-driven target lesion revascularisation. FUNDING: Biotronik.

Adjuvant everolimus after surgery for renal cell carcinoma (EVEREST): a double-blind, placebo-controlled, randomised, phase 3 trial.

BACKGROUND: Patients undergoing resection of renal cell carcinoma are at risk of disease relapse. We evaluated the effectiveness of the mammalian target of rapamycin inhibitor everolimus administered after surgery. METHODS: In this randomised, double-blind, phase 3 trial, we enrolled adults with histologically confirmed renal cell carcinoma who had undergone a full surgical resection and were at intermediate-high or very high risk of recurrence at 398 academic and community institution centres in the USA. After nephrectomy, patients were randomly assigned (1:1) via a central web-based application using a dynamic balancing algorithm to receive 10 mg oral everolimus daily or placebo for 54 weeks. The primary endpoint was recurrence-free survival. Efficacy analyses included all eligible, randomly assigned patients; safety analysis included all patients who received treatment. This trial is registered with ClinicalTrials.gov, NCT01120249 and is closed to new participants. FINDINGS: Between April 1, 2011, and Sept 15, 2016, a total of 1545 patients were randomly assigned to receive everolimus (n=775) or placebo (n=770), of whom 755 assigned to everolimus and 744 assigned to placebo were eligible for inclusion in the efficacy analysis. With a median follow-up of 76 months (IQR 61-92), recurrence-free survival was longer with everolimus than with placebo (5-year recurrence-free survival 67% [95% CI 63-70] vs 63% [60-67]; stratified log-rank p=0·050; stratified hazard ratio [HR] 0·85, 95% CI 0·72-1·00; p=0·051) but did not meet the prespecified p value for statistical significance of 0·044. Recurrence-free survival was longer with everolimus than with placebo in the very-high-risk group (HR 0·79, 95% CI 0·65-0·97; p=0·022) but not in the intermediate-high-risk group (0·99, 0·73-1·35; p=0·96). Grade 3 or higher adverse events occurred in 343 (46%) of 740 patients who received everolimus and 79 (11%) of 723 who received placebo. INTERPRETATION: Postoperative everolimus did not improve recurrence-free survival compared with placebo among patients with renal cell carcinoma at high risk of recurrence after nephrectomy. These results do not support the adjuvant use of everolimus for renal cell carcinoma after surgery. FUNDING: US National Institutes of Health, National Cancer Institute, National Clinical Trials Network, Novartis Pharmaceuticals Corporation, and The Hope Foundation.

Dipeptidyl Peptidase 4 Inhibition for Prophylaxis of Acute Graft-versus-Host Disease.

BACKGROUND: Dipeptidyl peptidase 4 (DPP-4; also known as CD26), a transmembrane receptor expressed on T cells, has a costimulatory function in activating T cells. In a mouse model, down-regulation of CD26 prevented graft-versus-host disease (GVHD) but preserved graft-versus-tumor effects. Whether inhibition of DPP-4 with sitagliptin may prevent acute GVHD after allogeneic stem-cell transplantation is not known. METHODS: We conducted a two-stage, phase 2 clinical trial to test whether sitagliptin plus tacrolimus and sirolimus would reduce the incidence of grade II to IV acute GVHD from 30% to no more than 15% by day 100. Patients received myeloablative conditioning followed by mobilized peripheral-blood stem-cell transplants. Sitagliptin was given orally at a dose of 600 mg every 12 hours starting the day before transplantation until day 14 after transplantation. RESULTS: A total of 36 patients who could be evaluated, with a median age of 46 years (range, 20 to 59), received transplants from matched related or unrelated donors. Acute GVHD occurred in 2 of 36 patients by day 100; the incidence of grade II to IV GVHD was 5% (95% confidence interval [CI], 1 to 16), and the incidence of grade III or IV GVHD was 3% (95% CI, 0 to 12). Nonrelapse mortality was zero at 1 year. The 1-year cumulative incidences of relapse and chronic GVHD were 26% (95% CI, 13 to 41) and 37% (95% CI, 22 to 53), respectively. GVHD-free, relapse-free survival was 46% (95% CI, 29 to 62) at 1 year. Toxic effects were similar to those seen in patients undergoing allogeneic stem-cell transplantation. CONCLUSIONS: In this nonrandomized trial, sitagliptin in combination with tacrolimus and sirolimus resulted in a low incidence of grade II to IV acute GVHD by day 100 after myeloablative allogeneic hematopoietic stem-cell transplantation. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT02683525.).

Mitigation of Anti-Drug Antibody Production for Augmenting Anticancer Efficacy of Therapeutic Protein via Co-Injection of Nano-Rapamycin.

The induction of anti-drug antibody (ADA) is a formidable challenge for protein-based therapy. Trichosanthin (TCS) as a class of ribosome-inactivating proteins is widely studied in tumor treatment. However, the immunogenicity can induce the formation of ADA, which can cause hypersensitivity reactions and neutralize the efficacy of TCS, thus limiting its clinical application in cancer therapy. Here, a promising solution to this issue is presented by co-administration of the rapamycin nanoparticles and TCS. PEGylated rapamycin amphiphilic molecule is designed and synthesized as a prodrug and a delivery carrier, which can self-assemble into a nanoparticle system with encapsulation of free rapamycin, a hydrophobic drug. It is found that co-injection of the PEGylated rapamycin nanoparticles and TCS could mitigate the formation of anti-TCS antibody via inducing durable immunological tolerance. Importantly, the combination of TCS and the rapamycin nanoparticles has an enhanced effect on inhibit the growth of breast cancer. This work provides a promising approach for protein toxin-based anticancer therapy and for promoting the clinical translation.

Prevention of neointimal hyperplasia after coronary artery bypass graft via local delivery of sirolimus and rosuvastatin: network pharmacology and in vivo validation.

BACKGROUND: Coronary artery bypass graft (CABG) is generally used to treat complex coronary artery disease. Treatment success is affected by neointimal hyperplasia (NIH) of graft and anastomotic sites. Although sirolimus and rosuvastatin individually inhibit NIH progression, the efficacy of combination treatment remains unknown. METHODS: We identified cross-targets associated with CABG, sirolimus, and rosuvastatin by using databases including DisGeNET and GeneCards. GO and KEGG pathway enrichment analyses were conducted using R studio, and target proteins were mapped in PPI networks using Metascape and Cytoscape. For in vivo validation, we established a balloon-injured rabbit model by inducing NIH and applied a localized perivascular drug delivery device containing sirolimus and rosuvastatin. The outcomes were evaluated at 1, 2, and 4 weeks post-surgery. RESULTS: We identified 115 shared targets between sirolimus and CABG among databases, 23 between rosuvastatin and CABG, and 96 among all three. TNF, AKT1, and MMP9 were identified as shared targets. Network pharmacology predicted the stages of NIH progression and the corresponding signaling pathways linked to sirolimus (acute stage, IL6/STAT3 signaling) and rosuvastatin (chronic stage, Akt/MMP9 signaling). In vivo experiments demonstrated that the combination of sirolimus and rosuvastatin significantly suppressed NIH progression. This combination treatment also markedly decreased the expression of inflammation and Akt signaling pathway-related proteins, which was consistent with the predictions from network pharmacology analysis. CONCLUSIONS: Sirolimus and rosuvastatin inhibited pro-inflammatory cytokine production during the acute stage and regulated Akt/mTOR/NF-κB/STAT3 signaling in the chronic stage of NIH progression. These potential synergistic mechanisms may optimize treatment strategies to improve long-term patency after CABG.

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.

Sirolimus plus prednisolone vs sirolimus monotherapy for kaposiform hemangioendothelioma: a randomized clinical trial.

The Kasabach-Merritt phenomenon (KMP) in kaposiform hemangioendothelioma (KHE) is characterized by life-threatening thrombocytopenia and consumptive coagulopathy. This study compared the efficacy and safety of sirolimus plus prednisolone vs sirolimus monotherapy as treatment strategies for KHE with KMP in the largest cohort to date. Participants were randomized to receive either sirolimus in combination with a short course of prednisolone or sirolimus monotherapy for at least 12 months. The primary outcome was defined as achievement of a durable platelet response (platelet count >100 × 109/L) at week 4. Participants completed efficacy assessments 2 years after the initial treatment. At week 4, a durable platelet response was achieved by 35 of 37 patients given sirolimus and prednisolone compared with 24 of 36 patients given sirolimus monotherapy (difference 27.9%; 95% confidence interval, 10.0-44.7). Compared with the sirolimus monotherapy group, the combination treatment group showed improvements in terms of measures of durable platelet responses at all points during the initial 3-week treatment period, median platelet counts during weeks 1 to 4, increased numbers of patients achieving fibrinogen stabilization at week 4, and objective lesion responses at month 12. Patients receiving combination therapy had fewer blood transfusions and a lower total incidence of disease sequelae than patients receiving sirolimus alone. The frequencies of total adverse events and grade 3-4 adverse events during treatment were similar in both groups. The responses seen in patients with KHE with KMP were profound and encouraging, suggesting that sirolimus plus prednisolone should be considered a valid treatment of KHE with KMP. This trial was registered at www.clinicaltrials.gov as #NCT03188068.

Study on the effects of rapamycin and the mTORC1/2 dual inhibitor OSI-027 on the metabolism of colon cancer cells based on UPLC-MS/MS metabolomics.

mTORC1/2 dual inhibitors may be more effective than mTORC1 inhibitor rapamycin. However, their metabolic impacts on colon cancer cells remain unexplored. We conducted a comparative analysis of the anti-proliferative effects of rapamycin and the novel OSI-027 in colon cancer cells HCT-116, evaluating their metabolic influences through ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Our results demonstrate that OSI-027 more effectively inhibits colon cancer cell proliferation than rapamycin. Additionally, we identified nearly 600 metabolites from the spectra, revealing significant differences in metabolic patterns between cells treated with OSI-027 and rapamycin. Through VIP value screening, we pinpointed crucial metabolites contributing to these distinctions. For inhibiting glycolysis and reducing glucose consumption, OSI-027 was likely to be more potent than rapamycin. For amino acids metabolism, although OSI-027 has a broad effect as rapamycin, their effects in degrees were not exactly the same. These findings address the knowledge gap regarding mTORC1/2 dual inhibitors and lay a foundation for their further development and research.

Role of mammalian target of rapamycin in the formation and progression of retinopathy of prematurity-like vascular abnormalities in neonatal rats.

Retinopathy of prematurity (ROP), a retinal disease that can occur in premature infants, can lead to severe visual impairment. In this study, we examined the preventive and therapeutic effects of mammalian target of rapamycin complex 1 (mTORC1) inhibition on abnormal retinal blood vessels in a rat model of ROP. To induce ROP-like vascular abnormalities, rats were subcutaneously treated with KRN633, an inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinase, on postnatal day 7 (P7) and P8. KRN633-treated (ROP) rats were treated subcutaneously with the mTORC1 inhibitor rapamycin according to preventive and therapeutic protocols, i.e., from P11 to P13 (P11-P13) and from P14 to P20 (P14-P20), respectively. To compare with the effects of VEGF inhibition, KRN633 was administered according to similar protocols. Changes in retinal vasculature, phosphorylated ribosomal protein S6 (pS6), a downstream indicator of mTORC1 activity, and the proliferative status of vascular cells were evaluated at P14 and P21 using immunohistochemistry. Rapamycin treatment from P11 to P13 prevented increases in arteriolar tortuosity, capillary density, and the number of proliferating vascular cells, and eliminated pS6 immunoreactivity in ROP rats. KRN633 treatment at P11 and P12 (P11/P12) also prevented the appearance of ROP-like retinal blood vessels. Rapamycin treatment from P14 to P20 failed to attenuate arteriolar tortuosity but prevented increases in capillary density and proliferating vascular cell number at the vascular front, but not at the central zone. KRN633 treatment from P14 to P20 significantly reduced abnormalities in the retinal vasculature; however, the effects were inferior to those of KRN633 treatment on P11/P12. These results suggest that activation of the mTORC1 pathway in proliferating endothelial cells contributes to the appearance and progression of ROP-like retinal blood vessels. Therefore, inhibition of mTORC1 may be a promising approach for selectively targeting abnormal retinal blood vessels in ROP.