Immunosuppressive Effects and Potent Anti-tumor Efficacy of mTOR Inhibitor Everolimus in Breast Tumor-bearing Mice

To investigate the effects of everolimus, a mechanistic/mammalian target of rapamycin (mTOR) inhibitor, on tumor growth and immune response in a mouse model of breast cancer. Human hormone receptor-positive (HR+)/human epidermal growth receptor 2-negative (HER2-) MC4-L2 cell line was used to establish a mouse model of breast cancer. The inhibitory effects of high (10 mg/kg) and low (5 mg/kg) doses of everolimus were investigated on tumor growth. Additionally, the frequency of CD4+Foxp3+ regulatory T cells (Tregs), CD8+Foxp3+ Tregs, and CD4+ and CD8+ T cells expressing cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) was explored by flow cytometry in bone marrow, lymph nodes, and spleen. Our results showed that both 10 mg/kg and 5 mg/kg doses of everolimus efficiently inhibited tumor growth, resulting in reduced breast tumor volume. In addition, it was revealed that everolimus-treated mice induced a higher frequency of CD4+Foxp3+ Tregs, CD8+Foxp3+ Tregs, and CD4+Foxp3+CTLA-4+ Tregs as well as CD4+ and CD8+ T cells expressing CTLA-4 in their bone marrow, lymph nodes, and spleen compared with standard control (vehicle-treated) in a dose-dependent manner. Furthermore, we found that everolimus treatment with 10 mg/kg and 5 mg/kg increased the frequency of Helios+Foxp3+ Tregs in the bone marrow of treated mice compared with the control group. Our results indicate that treatment with everolimus not only inhibits tumor growth but also exerts an immunomodulatory effect by inducing Tregs in the lymphoid organs of breast cancer-bearing mice. The combination of therapy with other anti-cancer agents may negate immune suppression and improve the efficacy of mTOR-targeted breast cancer therapy.

Safety and Clinical Performance of Biodegradable Polymer-Coated Ultra-Thin Everolimus-Eluting Stents in “Real-World” Patients: A Multicenter Registry (PERFORM-EVER)

Background:

Tetrilimus (Sahajanand Medical Technologies Limited, Surat, India) is a biodegradable polymer-coated everolimus-eluting stent with cobalt–chromium stent platform and ultra-thin (60 µm) strut thickness. We aimed to report 1-year safety and clinical performance of Tetrilimus everolimus-eluting stent in patients with coronary artery disease in “real-world” clinical practice.

Methods:

The PERFORMance of biodegradable polymer-coated ultra-thin EVERolimus-eluting stents was an observational, multicenter, single-arm, and investigator-initiated retrospective registry. All “real-world” patients who had received Tetrilimus everolimus-eluting stent between July-2015 and October-2016 at four study centers were analyzed. The data were collected retrospectively either by extraction from existing databases in consecutive fashion where index and follow-up data existed or the follow-up was obtained by telephonic contact. Primary endpoint was 1-year incidence of target lesion failure, which was defined as a composite endpoint of cardiac death, myocardial infarction, and target lesion revascularization by percutaneous or surgical methods. The Academic Research Consortium-defined stent thrombosis was assessed as additional safety endpoint.

Results:

During the study period, 815 Tetrilimus everolimus-eluting stents (1.4 ± 0.5 stent/patient) were implanted to treat 735 coronary lesions (1.1 ± 0.3 stent/lesion) in 594 patients (mean age: 55.6 ± 12.1 years). The cumulative incidence of target lesion failure at 1-year follow-up was 3.7%, which included 9 (1.5%) cardiac deaths, 8 (1.4%) myocardial infarctions, and 5 (0.8%) target lesion revascularizations. There were 5 (0.8%) cases of probable stent thrombosis and 4 (0.7%) cases of possible stent thrombosis at 1-year follow-up.

Conclusion:

Low incidences of target lesion failure and stent thrombosis at 1-year follow-up indicates that biodegradable polymer-coated ultra-thin Tetrilimus everolimus-eluting stents may have encouraging safety and efficacy in unselected real-world patients with coronary artery disease, including those with high-risk characteristics and complex lesions.

The Synergistic Effect of Tacrolimus (FK506) or Everolimus and Azoles Against Scedosporium and Lomentospora Species In Vivo and In Vitro

Scedosporium and Lomentospora infections in humans are generally chronic and stubborn. The use of azoles alone cannot usually inhibit the growth of these fungi. To further explore the combined effect of multiple drugs and potential mechanisms of action, we tested the antifungal effects of tacrolimus (FK506) and everolimus in combination with azoles in vitro and in vivo on 15 clinical strains of Scedosporium/Lomentospora species and detected the level of Rhodamine 6G, ROS activity, and apoptosis. The in vitro results showed that the combinations of tacrolimus with itraconazole, voriconazole, and posaconazole showed synergistic effects on 9 strains (60%), 10 strains (73%), and 7 strains (47%), respectively, and the combinations of everolimus with itraconazole, voriconazole, and posaconazole showed synergistic effects on 8 strains (53%), 8 strains (53%), and 7 strains (47%), respectively. The synergistic effects might correspond to the elevated ROS activity (the tacrolimus + itraconazole group compared to the itraconazole group, (P < 0.05)), early apoptosis (itraconazole (P < 0.05) and voriconazole (P < 0.05) combined with everolimus), and late apoptosis (the tacrolimus + itraconazole group compared to the itraconazole group, (P < 0.01); the tacrolimus + posaconazole group compared to the posaconazole group, (P < 0.05)), but not inhibition of efflux pump activity. Our in vitro results suggested that a combination of tacrolimus or everolimus and azoles have a synergistic effect against Scedosporium/Lomentospora. The synergistic mechanisms of action might be triggering excessive ROS activity and apoptosis. In vivo, the survival rate of G. mellonella (sixth instar larvae) was significantly improved by tacrolimus alone, everolimus alone, azoles alone, and tacrolimus and everolimus combined with azoles separately (P < 0.05 for the tacrolimus group; P < 0.01 for the everolimus group and the itraconazole group; P = 0.0001 for the tacrolimus and posaconazole group; P < 0.0001 for other groups except the everolimus and itraconazole group, everolimus and posaconazole group, and tacrolimus and itraconazole group). From the results, we infer that the combination of tacrolimus or everolimus with azoles has obvious synergistic effect on Scedosporium/Lomentospora, and might enhance the level of apoptosis and necrosis. However, the synergistic effects were not related to the efflux pump. In conclusion, from our in vitro and in vivo study, tacrolimus and everolimus combined with azoles may have a synergistic effect in the treatment against Scedosporium/Lomentospora, improving the drug activity of azoles and promoting a better prognosis for patients.

The Effects of PI3K/Akt/mTOR Signaling Pathway Inhibitors on the Expression of Immune Checkpoint Ligands in Acute Myeloid Leukemia Cell Line

Up-regulation of immune checkpoint ligands is considered as one of the most important immune escape mechanisms in acute myeloid leukemia (AML). Herein, we investigate a relationship between the inhibition of PI3K/Akt/mTOR signaling pathways and the regulation of immune checkpoint ligands in AML cells. The HL-60 cell line was treated with idelalisib as PI3K inhibitor, MK-2206 as Akt inhibitor, and everolimus as mTOR inhibitor either in a single or combined format. Cell viability and apoptosis were evaluated using MTT and flow cytometry assays, respectively. The relative expression of PD-L1, galectin-9, and CD155 was determined by real-time PCR. Our findings demonstrated decreased proliferation and increased apoptosis of HL-60 cells after treatment with idelalisib, MK-2206, and everolimus. As expected, the combined treatment showed a more inhibiting effect than the single treatment. Interestingly, our results elucidated that the expression of PD-L1 and Gal-9 but not MK-2206 decreased after treatment with idelalisib and everolimus. Regarding CD155, the expression of this molecule was downregulated after treatment with everolimus, but not idelalisib and MK-2206. However, combined treatment of HL-60 cells with two or three inhibitors decreased the expression levels of PD-L1, Gal-9, and CD155 checkpoint ligands. We showed that PI3K/Akt/mTOR pathway inhibitors not only serve as cytotoxic drugs but also regulate the expression of immune checkpoint ligands and interfere with the immune evasion mechanisms of AML leukemic cells. Combinational treatment approaches to block these pathways might be a promising and novel therapeutic strategy for AML patients via interfering in immune escape mechanisms.

Synergistic anticancer effects of everolimus (RAD001) and Rhein on gastric cancer cells via phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway

Everolimus (RAD001) is a mTOR inhibitor and is widely used for the treatment of gastric cancer (GC). Evidence suggests that Rhein has anticancer effect on GC. But the synergistic effect and mechanism of RAD001 and Rhein combination on GC is not clear. The current study aims to clarify the combination of RAD001 and Rhein in GC treatment. We found Rhein dose-dependently repressed MGC-803 cell viability (50% inhibition concentration (IC50) value = 94.26 μM). Rhein (80 μM) significantly suppressed GC cell proliferation and invasion. RAD001 dose-dependently repressed MGC-803 cells viability (IC50 value = 45.41 nM). The combination of Rhein and RAD001 repressed MGC-803 cells viability, invasion, and proliferation compared to the administration of Rhein or RAD001 alone. Protein levels of epithelial-mesenchymal transition (EMT)-related molecules E-cadherin, N-cadherin and Vimentin expressions were significantly affected by the combination of Rhein and RAD001. The combination of Rhein and RAD001 significantly facilitated cell apoptosis and up-regulated expressions of cell apoptosis and cycle-related protein p53, cyclin-dependent kinase 4 (CDK4) and cyclin D1 compared to the administration of Rhein or RAD001 alone. Moreover, the combination of Rhein and RAD001 repressed the expressions of phosphorylation-phosphoinositide-3-kinase (p-PI3K), p-protein kinase B (p-AKT) and p-mammalian target of rapamycin (p-mTOR). Finally, the combination of RAD001 and Rhein significantly decreased tumor weight and volume, suppressed the expressions of p-PI3K, p-Akt and p-mTOR, and repressed cell proliferation marker Ki-67 expression, which exerted synergistic cancer prevention in GC in vivo. Overall, the combination of Rhein and RAD001 exert synergistic cancer prevention in GC via PI3K/Akt/mTOR pathway.

Procedural and One-Year Clinical Outcomes of Long 48 mm Xience Xpedition Everolimus-Eluting Stent in Complex Long Diffuse Coronary Artery Lesions

BACKGROUND AND OBJECTIVES

Long 48 mm drug-eluting stents (DES) used to treat long coronary lesions decreases the number of stents needed and avoids stent overlapping. Disadvantages include difficulty in delivery and size discrepancy between proximal and distal stent landing zones. The present study analyzed the rate of procedural, immediate angiographic, and 1-year clinical outcomes of long diffuse coronary artery lesions treated with 48 mm everolimus-eluting stents (EES) and compared the clinical outcomes with multiple overlapping DES.

METHODS

This retrospective analysis included 213 patients with 228 lesions treated with at least one 48 mm EES at 2 hospitals in Taiwan.

RESULTS

About 40.4% of the lesions had moderate-severe calcification and 20.2% had acute angulation. The mean lesion length was 49.2 ± 18.1 mm. In 161 lesions requiring a single 48 mm EES, 67.1% had a discrepancy between proximal and distal reference diameter of ≥0.5 mm and 36% had a discrepancy of ≥1.0 mm. The procedural success rate was 98.6%. Target-vessel failure (TVF) rate at 1 year was 4.2%. Cardiac death occurred in 3 patients. The rates of target-vessel myocardial infarction (TV-MI), target-vessel revascularization (TVR) and definite/ probable stent thrombosis were 1.4%, 3.3%, and 0.9%, respectively. After adjusting patient variables by propensity score matching, no significant difference was found for cardiac death, TVF, TV-MI, and clinically driven TVR.

CONCLUSION

Use of 48 mm EES to treat long coronary lesions in clinically and anatomically complex patients is safe and effective. In the propensity score-matched analysis, the 48 mm EES and multiple stents have comparable clinical outcomes.

Everolimus Alleviates Renal Allograft Interstitial Fibrosis by Inhibiting Epithelial-to-Mesenchymal Transition Not Only via Inducing Autophagy but Also via Stabilizing IκB-α

Chronic allograft dysfunction (CAD) is the major cause of late graft loss in long-term renal transplantation. In our previous study, we found that epithelial–mesenchymal transition (EMT) is a significant event in the progression of renal allograft tubulointerstitial fibrosis, and impaired autophagic flux plays a critical role in renal allograft fibrosis. Everolimus (EVR) has been reported to be widely used to prevent the progression of organ fibrosis and graft rejection. However, the pharmacological mechanism of EVR in kidney transplantation remains to be determined. We used CAD rat model and the human kidney 2 (HK2) cell line treated with tumor necrosis factor-α (TNF-α) and EVR to examine the role of EVR on TNF-α-induced EMT and transplanted renal interstitial fibrosis. Here, we found that EVR could attenuate the progression of EMT and renal allograft interstitial fibrosis, and also activate autophagy in vivo. To explore the mechanism behind it, we detected the relationship among EVR, autophagy level, and TNF-α-induced EMT in HK2 cells. Our results showed that autophagy was upregulated upon mTOR pathway inhibition by EVR, which could significantly reduce expression of TNF-α-induced EMT. However, the inhibition of EVR on TNF-α-induced EMT was partly reversed following the addition of autophagy inhibitor chloroquine. In addition, we found that TNF-α activated EMT through protein kinase B (Akt) as well as nuclear factor kappa B (NF-κB) pathway according to the RNA sequencing, and EVR’s effect on the EMT was only associated with IκB-α stabilization instead of the Akt pathway. Together, our findings suggest that EVR may retard impaired autophagic flux and block NF-κB pathway activation, and thereby prevent progression of TNF-α-induced EMT and renal allograft interstitial fibrosis.

Norcantharidin counteracts acquired everolimus resistance in renal cell carcinoma by dual inhibition of mammalian target of rapamycin complex 1 and complex 2 pathways in Vitro

Everolimus, an oral mammalian target of rapamycin complex 1 (mTORC1) inhibitor, presents a therapeutic option in metastatic renal cell carcinoma (RCC) patients who were intolerant to, or previously failed, immune- and vascular endothelial growth factor-targeted therapies. However, the onset of drug resistance limits its clinical use. One possible mechanism underpinning the resistance is that inhibiting mTORC1 by everolimus results in mTORC2-dependent activation of v-Akt murine thymoma viral oncogene (AKT) and upregulation of hypoxia-inducible transcription factors (HIF). Norcantharidin (NCTD) is a demethylated derivative of cantharidin with antitumor properties which is an active ingredient of the traditional Chinese medicine Mylabris. In this study, everolimus-resistant RCC cells (786-O-R) obtained by chronic everolimus treatment revealed higher level of HIF2α and over-activated mTORC2 pathway and NCTD inhibits cell proliferation in both everolimus-resistant and -sensitive RCC cells by arresting cell cycle in G0/G1 phase and reducing cell cycle-related proteins of C-Myc and cyclin D. Furthermore, NCTD shows synergistic anticancer effects combined with everolimus in everolimus-resistant 786-O-R cells. Mechanically, NCTD repressed both mTORC1 and mTORC2 signaling pathways as well as downstream molecular signaling pathways, such as p-4EBP1, p-AKT, HIF1α and HIF2α. Our findings provide sound evidence that combination of NCTD and everolimus is a potential therapeutic strategy for treating RCC and overcoming everolimus resistance by dual inhibition of mTORC1 and mTORC2.

DRD2 Agonist Cabergoline Abolished the Escape Mechanism Induced by mTOR Inhibitor Everolimus in Tumoral Pituitary Cells

The mammalian target of rapamycin (mTOR) inhibitor everolimus has been shown to display antiproliferative effects on a wide spectrum of tumors. In vitro studies demonstrated that everolimus inhibited pituitary neuroendocrine tumor (PitNET) cell growth in a subset of patients. Sensitivity to everolimus is reduced by an escape mechanism that increases AKT phosphorylation (p-AKT), leading to pro-survival pathway activation. Dopamine receptor type 2 (DRD2) mediates a reduction of p-AKT in a subgroup of non-functioning PitNETs (NF-PitNETs) and in prolactin-secreting tumor cells (MMQ cells) through a β-arrestin 2-dependent mechanism. The aim of this study was to investigate the efficacy of everolimus combined with DRD2 agonist cabergoline in reducing NF-PitNET primary cells and MMQ cell proliferation and to evaluate AKT phosphorylation and a possible role of β-arrestin 2. We found that 9 out of 14 NF-PitNETs were resistant to everolimus, but the combined treatment with cabergoline inhibited cell proliferation in 7 out of 9 tumors (-31.4 ± 9.9%, p < 0.001 vs. basal) and reduced cyclin D3 expression. In the everolimus-unresponsive NF-PitNET group, everolimus determined a significant increase of p-AKT/total-AKT ratio (2.1-fold, p < 0.01, vs. basal) that was reverted by cabergoline cotreatment. To investigate the molecular mechanism involved, we used MMQ cells as a model of everolimus escape mechanism. Indeed everolimus did not affect MMQ cell proliferation and increased the p-AKT/total-AKT ratio (+1.53 ± 0.24-fold, p < 0.001 vs. basal), whereas cabergoline significantly reduced cell proliferation (-22.8 ± 6.8%, p < 0.001 vs. basal) and p-AKT. The combined treatment of everolimus and cabergoline induced a reduction of both cell proliferation (-34.8 ± 18%, p < 0.001 vs. basal and p < 0.05 vs. cabergoline alone) and p-AKT/total-AKT ratio (-34.5 ± 14%, p < 0.001 vs. basal and p < 0.05 vs. cabergoline alone). To test β-arrestin 2 involvement, silencing experiments were performed in MMQ cells. Our data showed that the lack of β-arrestin 2 prevented the everolimus and cabergoline cotreatment inhibitory effects on both p-AKT and cell proliferation. In conclusion, this study revealed that cabergoline might overcome the everolimus escape mechanism in NF-PitNETs and tumoral lactotrophs by inhibiting upstream AKT activation. The co-administration of cabergoline might improve mTOR inhibitor antitumoral activity, paving the way for a potential combined therapy in β-arrestin 2-expressing NF-PitNETs or other PitNETs resistant to conventional treatments.

Effect of Everolimus versus Bone Marrow-Derived Stem Cells on Glomerular Injury in a Rat Model of Glomerulonephritis: A Preventive, Predictive and Personalized Implication

Glomerular endothelial injury and effectiveness of glomerular endothelial repair play a crucial role in the progression of glomerulonephritis. Although the potent immune suppressive everolimus is increasingly used in renal transplant patients, adverse effects of its chronic use have been reported clinically in human glomerulonephritis and experimental renal disease. Recent studies suggest that progenitor stem cells could enhance glomerular endothelial repair with minimal adverse effects. Increasing evidence supports the notion that stem cell therapy and regenerative medicine can be effectively used in pathological conditions within the predictive, preventive and personalized medicine (PPPM) paradigm. In this study, using an experimental model of glomerulonephritis, we tested whether bone marrow-derived stem cells (BMDSCs) could provide better effect over everolimus in attenuating glomerular injury and improving the repair process in a rat model of glomerulonephritis. Anti-Thy1 glomerulonephritis was induced in male Sprague Dawley rats by injection of an antibody against Thy1, which is mainly expressed on glomerular mesangial cells. Additional groups of rats were treated with the immunosuppressant everolimus daily after the injection of anti-Thy1 or injected with single bolus dose of BMDSCs after one week of injection of anti-Thy1 (n = 6-8). Nine days after injection of anti-Thy1, glomerular albumin permeability and albuminuria were significantly increased when compared to control group (p < 0.05). Compared to BMDSCs, everolimus was significantly effective in attenuating glomerular injury, nephrinuria and podocalyxin excretion levels as well as in reducing inflammatory responses and apoptosis. Our findings suggest that bolus injection of BMDSCs fails to improve glomerular injury whereas everolimus slows the progression of glomerular injury in Anti-Thy-1 induced glomerulonephritis. Thus, everolimus could be used at the early stage of glomerulonephritis, suggesting potential implications of PPPM in the treatment of progressive renal injury.

The glutaminase inhibitor telaglenastat enhances the antitumor activity of signal transduction inhibitors everolimus and cabozantinib in models of renal cell carcinoma

Dysregulated metabolism is a hallmark of cancer that manifests through alterations in bioenergetic and biosynthetic pathways to enable tumor cell proliferation and survival. Tumor cells exhibit high rates of glycolysis, a phenomenon known as the Warburg effect, and an increase in glutamine consumption to support the tricarboxylic acid (TCA) cycle. Renal cell carcinoma (RCC) tumors express high levels of glutaminase (GLS), the enzyme required for the first step in metabolic conversion of glutamine to glutamate and the entry of glutamine into the TCA cycle. We found that RCC cells are highly dependent on glutamine for proliferation, and this dependence strongly correlated with sensitivity to telaglenstat (CB-839), an investigational, first-in-class, selective, orally bioavailable GLS inhibitor. Metabolic profiling of RCC cell lines treated with telaglenastat revealed a decrease in glutamine consumption, which was concomitant with a decrease in the production of glutamate and other glutamine-derived metabolites, consistent with GLS inhibition. Treatment of RCC cells with signal transduction inhibitors everolimus (mTOR inhibitor) or cabozantinib (VEGFR/MET/AXL inhibitor) in combination with telaglenastat resulted in decreased consumption of both glucose and glutamine and synergistic anti-proliferative effects. Treatment of mice bearing Caki-1 RCC xenograft tumors with cabozantinib plus telaglenastat resulted in reduced tumor growth compared to either agent alone. Enhanced anti-tumor activity was also observed with the combination of everolimus plus telaglenastat. Collectively, our results demonstrate potent, synergistic, anti-tumor activity of telaglenastat plus signal transduction inhibitors cabozantinib or everolimus via a mechanism involving dual inhibition of glucose and glutamine consumption.

Everolimus and plicamycin specifically target chemoresistant colorectal cancer cells of the CMS4 subtype

Colorectal cancers (CRC) can be classified into four consensus molecular subtypes (CMS), among which CMS1 has the best prognosis, contrasting with CMS4 that has the worst outcome. CMS4 CRC is notoriously resistant against therapeutic interventions, as demonstrated by preclinical studies and retrospective clinical observations. Here, we report the finding that two clinically employed agents, everolimus (EVE) and plicamycin (PLI), efficiently target the prototypic CMS4 cell line MDST8. As compared to the prototypic CMS1 cell line LoVo, MDST8 cells treated with EVE or PLI demonstrated stronger cytostatic and cytotoxic effects, increased signs of apoptosis and autophagy, as well as a more pronounced inhibition of DNA-to-RNA transcription and RNA-to-protein translation. Moreover, nontoxic doses of EVE and PLI induced the shrinkage of MDST8 tumors in mice, yet had only minor tumor growth-reducing effects on LoVo tumors. Altogether, these results suggest that EVE and PLI should be evaluated for their clinical activity against CMS4 CRC.

Initial Experiences of Percutaneous Coronary Intervention Using a New-Generation Everolimus-Eluting Stent Platform

BACKGROUND

Outcomes from the new Synergy Megatron drug-eluting stent (DES) platform (Boston Scientific) are not yet reported. This study sought to evaluate periprocedural outcomes in patients undergoing percutaneous coronary intervention (PCI) using this technology.

METHODS

This was a retrospective study across two United Kingdom centers of 139 patients undergoing PCI of 146 coronary lesions using the Synergy Megatron DES. The primary endpoint was the rate of cardiovascular death. The secondary endpoint was the rate of a composite of non-fatal myocardial infarction, target-vessel revascularization, in-stent restenosis, and probable/definite stent thrombosis. Available intravascular ultrasound (IVUS) imaging was reviewed post hoc and evaluated according to predefined IVUS optimization criteria.

RESULTS

Mean follow-up duration was 137.3 ± 38.3 days. The primary endpoint occurred in 0.7% of patients and the secondary endpoint occurred in 0.0% of patients. There were no cases of longitudinal stent deformation (LSD); in patients undergoing an IVUS-guided procedure, our criteria for successful IVUS optimization was achieved in 74.1% of left main stem (LMS) and 83.3% of right coronary artery (RCA) lesions. Mean minimal stent area (MSA) was 14.5 ± 3.4 mm² in the LMS, 10.0 ± 2.5 mm² in the left anterior descending coronary artery, 9.8 ± 3.0 mm² in the left circumflex, and 12.2 ± 4.0 mm² in the RCA.

CONCLUSION

This study demonstrated very low rates of short-term major adverse cardiovascular events with no cases of LSD or acute/subacute stent thrombosis. It highlights the overexpansion capabilities of the Synergy Megatron DES platform. The technology safely and effectively facilitates IVUS-optimized stent parameters for the treatment of large proximal vessels and bifurcations.

Synergistic melanoma cell death mediated by inhibition of both MCL1 and BCL2 in high-risk tumors driven by NF1/PTEN loss

Melanomas driven by loss of the NF1 tumor suppressor have a high risk of treatment failure and effective therapies have not been developed. Here we show that loss-of-function mutations of nf1 and pten result in aggressive melanomas in zebrafish, representing the first animal model of NF1-mutant melanomas harboring PTEN loss. MEK or PI3K inhibitors show little activity when given alone due to cross-talk between the pathways, and high toxicity when given together. The mTOR inhibitors, sirolimus, everolimus, and temsirolimus, were the most active single agents tested, potently induced tumor-suppressive autophagy, but not apoptosis. Because addition of the BCL2 inhibitor venetoclax resulted in compensatory upregulation of MCL1, we established a three-drug combination composed of sirolimus, venetoclax, and the MCL1 inhibitor S63845. This well-tolerated drug combination potently and synergistically induces apoptosis in both zebrafish and human NF1/PTEN-deficient melanoma cells, providing preclinical evidence justifying an early-stage clinical trial in patients with NF1/PTEN-deficient melanoma.

Ultrathin biodegradable polymer sirolimus-eluting stent versus contemporary durable polymer everolimus-eluting stent for percutaneous coronary intervention: a meta-analysis of randomized trials

INTRODUCTION

Improvements in coronary drug-eluting stent technology has focused on reducing the long-term complications associated with the effects of the residual footprint on the vessel wall. Although many of the newer stents have exhibited noninferiority to the durable polymer everolimus-eluting stent (DP-EES), they have yet to exhibit clear superiority. We compared the performance of the latest ultrathin strut biodegradable polymer sirolimus-eluting stents (BP-SES) to DP-EES.

METHODS

We searched the electronic databases for randomized controlled trials comparing BP-SES to DP-EES. A random effect meta-analysis was performed using the Poisson regression model. The primary end point was target lesion failure (TLF), a composite of target vessel myocardial infarction (TVMI), cardiac death and target lesion revascularization (TLR).

RESULTS

There was no difference between the stents in stent thrombosis [incidence rate ratio (IRR) = 0.79, 95% confidence interval (CI) 0.58-1.06), TLR (IRR = 0.88, 95% CI 0.57-1.38), TVMI (IRR = 0.79, 95% CI 0.61-1.01), cardiac death (IRR = 0.99, 95% CI 0.76-1.29) and target vessel failure (IRR = 0.82, 95% CI 0.64-1.06). In addition, there was no difference in TLF (IRR = 0.82, 95% CI 0.64-1.06). There was evidence of reduced TLF in small vessels with BP-SES based on definition used (defined as ≤2.75 mm; IRR 0.64, 95% CI 0.46-0.91 versus ≤3 mm; IRR 1.11, 95% CI 0.90-1.36).

CONCLUSION

In our study, the performance of the latest generation BP-SES was comparable to DP-EES but failed to show superiority. The possible benefit in patients with small vessels should be explored future trials.

ER+ Breast Cancer Strongly Depends on MCL-1 and BCL-xL Anti-Apoptotic Proteins

Breast cancer is the most frequent type of cancer and the major cause of mortality in women. The rapid development of various therapeutic options has led to the improvement of treatment outcomes; nevertheless, one-third of estrogen receptor (ER)-positive patients relapse due to cancer cell acquired resistance. Here, we use dynamic BH3 profiling (DBP), a functional predictive assay that measures net changes in apoptotic priming, to find new effective treatments for ER+ breast cancer. We observed anti-apoptotic adaptations upon treatment that pointed to metronomic therapeutic combinations to enhance cytotoxicity and avoid resistance. Indeed, we found that the anti-apoptotic proteins BCL-xL and MCL-1 are crucial for ER+ breast cancer cells resistance to therapy, as they exert a dual inhibition of the pro-apoptotic protein BIM and compensate for each other. In addition, we identified the AKT inhibitor ipatasertib and two BH3 mimetics targeting these anti-apoptotic proteins, S63845 and A-1331852, as new potential therapies for this type of cancer. Therefore, we postulate the sequential inhibition of both proteins using BH3 mimetics as a new treatment option for refractory and relapsed ER+ breast cancer tumors.

Precision Therapy for Epilepsy Related to Brain Malformations

Malformations of cortical development (MCDs) represent a range of neurodevelopmental disorders that are collectively common causes of developmental delay and epilepsy, especially refractory childhood epilepsy. Initial treatment with antiseizure medications is empiric, and consideration of surgery is the standard of care for eligible patients with medically refractory epilepsy. In the past decade, advances in next generation sequencing technologies have accelerated progress in understanding the genetic etiologies of MCDs, and precision therapies for focal MCDs are emerging. Notably, mutations that lead to abnormal activation of the mammalian target of rapamycin (mTOR) pathway, which provides critical control of cell growth and proliferation, have emerged as a common cause of malformations. These include tuberous sclerosis complex (TSC), hemimegalencephaly (HME), and some types of focal cortical dysplasia (FCD). TSC currently represents the best example for the pathway from gene discovery to relatively safe and efficacious targeted therapy for epilepsy related to MCDs. Based on extensive pre-clinical and clinical data, the mTOR inhibitor everolimus is currently approved for the treatment of focal refractory seizures in patients with TSC. Although clinical studies are just emerging for FCD and HME, we believe the next decade will bring significant advancements in precision therapies for epilepsy related to these and other MCDs.

New Insights into Red Blood Cell Microcytosis upon mTOR Inhibitor Administration

The aim of this study was to evaluate the effect of everolimus, a mammalian target of rapamycin (mTOR) inhibitor, on red blood cell parameters in the context of iron homeostasis in patients with tuberous sclerosis complex (TSC) and evaluate its effect on cell size in vitro. Everolimus has a significant impact on red blood cell parameters in patients with TSC. The most common alteration was microcytosis. The mean MCV value decreased by 9.2%, 12%, and 11.8% after 3, 6, and 12 months of everolimus treatment. The iron level declined during the first 3 months, and human soluble transferrin receptor concentration increased during 6 months of therapy. The size of K562 cells decreased when cultured in the presence of 5 μM everolimus by approximately 8%. The addition of hemin to the cell culture with 5 μM everolimus did not prevent any decrease in cell size. The stage of erythroid maturation did not affect the response to everolimus. Our results showed that the mTOR inhibitor everolimus caused red blood cell microcytosis in vivo and in vitro. This effect is not clearly related to a deficit of iron and erythroid maturation. This observation confirms that mTOR signaling plays a complex role in the control of cell size.

Target therapies plus somatostatin analogs in NETs: a network meta-analysis

Although combination therapy is not recommended in patients with gastro-entero-pancreatic (GEP) neuroendocrine tumors (NETs), this strategy is widely used in clinical practice. This network meta-analysis of randomized trials evaluates targeted therapies and somatostatin analogues in GEP-advanced NETs, either alone or in combination, comparing the efficacy of different, single or combined treatment strategies in terms of progression-free survival (PFS). Interventions were grouped as analogs, everolimus, everolimus plus SSAs, sunitinib and placebo. In a secondary analysis, we also assessed the efficacy of individual-specific pharmacological treatments vs placebo or each other. From 83 studies identified, 8 randomized controlled trials were selected, with a total of 1849 patients with either functioning or non-functioning NETs. The analysis confirmed the superiority of all treatments over placebo (HR ranging from 0.34, 95% CI: 0.24-0.37 with the combination of everolimus plus SSAs to 0.42, 0.31-0.57 with the analogs; moderate quality of evidence). On ranking analysis, the combination of everolimus plus SSA (P score = 0.86) and then everolimus alone (P score = 0.65) ranked highest in increasing PFS. On comparative evaluation of different interventions, pasireotide (P score = 0.96) and everolimus + octreotide (P score = 0.82) ranked as the best pharmacological treatment options. Our findings support the use of combination therapy in the treatment of functioning and non-functioning GEP NETs. The role of pasireotide should be explored in selected subgroups of patients. Lastly, the combination of everolimus and octreotide appears promising and should be more widely considered in clinical practice.

Everolimus-induced effector mechanism in macrophages and survivability of Erdman, CDC1551 and HN878 strains of Mycobacterium tuberculosis infection

With a disease as widespread and destructive as tuberculosis, more effective drugs and healthcare strategies, in addition to the current antibiotics regimen, are crucial for the enhanced well-being of millions of people suffering from the disease. Host-directed therapy is a new and emerging concept in treating chronic infectious diseases, such as tuberculosis. Repurposing of anti-cancer drugs, such as everolimus, may be an effective way to supplement the standard antibiotic treatment. Individuals with type 2 diabetes are increasingly susceptible to co-morbidities and co-infections including Mycobacterium tuberculosis, the causative agent of tuberculosis. We demonstrated in this study that in vitro everolimus treatment of granulomas from individuals with type 2 diabetes caused significant reduction in the viability of Mycobacterium tuberculosis.Further investigations revealed the effects of everolimus in targeting foamy macrophages, a macrophage phenotype that forms around granulomas, and is characterized by a higher lipid accumulation inside the cells. These foamy macrophages are thought to harbor dormant bacilli, which are potential sources of disease reactivation. Therefore, blocking foamy macrophage formation would help better killing of intracellular bacteria. Here, we report the potential of everolimus treatment to downregulate lipid content within the foamy macrophages of in vitro granulomas, thus leading to a potential decrease in the number of foamy macrophages and a more robust response to Mycobacterium tuberculosis.

Biodegradable polymer sirolimus-eluting stents vs durable polymer everolimus-eluting stents in patients undergoing percutaneous coronary intervention: A meta-analysis of individual patient data from 5 randomized trials

BACKGROUND

Newest generation drug-eluting stents combine biodegradable polymers with ultrathin stent platforms in order to minimize vessel injury and inflammatory response. Evidence from randomized controlled trials suggested that differences in stent design translate into differences in clinical outcome. The aim of the present study was to evaluate the safety and efficacy of ultrathin strut, biodegradable polymer sirolimus eluting stents (BP SES) compared with thin strut, durable polymer everolimus-eluting stents (DP EES) among patients undergoing percutaneous coronary intervention (PCI).

METHODS

We pooled individual participant data from 5 randomized trials (NCT01356888, NCT01939249, NCT02389946, NCT01443104, NCT02579031) including a total of 5,780 patients, and performed a one-stage meta-analysis using a mixed effects Cox regression model.

RESULTS

At a median duration of follow-up of 739 days (interquartile range 365-1,806 days), target-lesion failure occurred in 337 (10.3%) and 304 (12.2%) patients treated with BP SES and DP EES (HR 0.86, 95%CI 0.71-1.06, P = .16). There were no significant differences between BP SES and DP EES with regards to cardiac death (111 (3.4%) vs 102 (4.1%); HR 1.05, 95%CI 0.80-1.37, P = .73), target-vessel myocardial infarction (136 (4.1%) vs 126 (5.0%), HR 0.79, 95%CI 0.62-1.01, P = .061), and clinically-driven target-lesion revascularization (163 (5.0%) vs 147 (5.9%); HR 0.94, 95%CI 0.75-1.18, P = .61). The effect was consistent across major subgroups. In a landmark analysis, there was no significant interaction between treatment effect and timing of events.

CONCLUSIONS

In this patient-level meta-analysis of 5 randomized controlled trials, BP SES were associated with a similar risk of target-lesion failure compared with DP EES among patients undergoing PCI.

STUDY REGISTRATION

PROSPERO registry (CRD42018109098).

Everolimus regulates the activity of gemcitabine-resistant pancreatic cancer cells by targeting the Warburg effect via PI3K/AKT/mTOR signaling

BACKGROUND

Gemcitabine (GEM) resistance remains a significant clinical challenge in pancreatic cancer treatment. Here, we investigated the therapeutic utility of everolimus (Evr), an inhibitor of mammalian target of rapamycin (mTOR), in targeting the Warburg effect to overcome GEM resistance in pancreatic cancer.

METHODS

The effect of Evr and/or mTOR overexpression or GEM on cell viability, migration, apoptosis, and glucose metabolism (Warburg effect) was evaluated in GEM-sensitive (GEMsen) and GEM-resistant (GEMres) pancreatic cancer cells.

RESULTS

We demonstrated that the upregulation of mTOR enhanced cell viability and favored the Warburg effect in pancreatic cancer cells via the regulation of PI3K/AKT/mTOR signaling. However, this effect was counteracted by Evr, which inhibited aerobic glycolysis by reducing the levels of glucose, lactic acid, and adenosine triphosphate and suppressing the expression of glucose transporter 1, lactate dehydrogenase-B, hexokinase 2, and pyruvate kinase M2 in GEMsen and GEMres cells. Evr also promoted apoptosis by upregulating the pro-apoptotic proteins Bax and cytochrome-c and downregulating the anti-apoptotic protein Bcl-2. GEM was minimally effective in suppressing GEMres cell activity, but the therapeutic effectiveness of Evr against pancreatic cancer growth was greater in GEMres cells than that in GEMsen cells. In vivo studies confirmed that while GEM failed to inhibit the progression of GEMres tumors, Evr significantly decreased the volume of GEMres tumors while suppressing tumor cell proliferation and enhancing tumor apoptosis in the presence of GEM.

CONCLUSIONS

Evr treatment may be a promising strategy to target the growth and activity of GEM-resistant pancreatic cancer cells by regulating glucose metabolism via inactivation of PI3K/AKT/mTOR signaling.

Ribociclib and everolimus in well-differentiated foregut neuroendocrine tumors

The mammalian target of rapamycin inhibitor everolimus is an established therapy for well-differentiated (WD) foregut neuroendocrine tumors (NETs). Pre-clinical data demonstrates a potential synergistic role for cyclin dependent kinase 4/6 inhibition and everolimus to treat this disease. In this phase II multicenter study, patients with advanced foregut WDNETs received combination ribociclib and everolimus until confirmed disease progression or unacceptable toxicity. The first 12 patients received ribociclib 300 mg three weeks in a row with a 1 week break and everolimus 2.5 mg daily (recommended phase II dose). Due to unexpected hematologic and infectious toxicities, the trial was put on hold, modified, and an additional 9 patients received ribociclib 200 mg and everolimus 2.5 mg daily. The primary end point was progression-free survival. Archived pre-treatment tumor was profiled by next-generation sequencing to evaluate for genomic markers of drug response. Twenty-one patients were treated (median age, 56; range, 24 to 77). The study did not meet the pre-specified criteria to advance to stage two. No patients experienced an objective response. Thirteen patients (62%) experienced stable disease. Median progression-free survival was 7.7 months (95% CI, 2.8 months to not reached). Eleven of the first 12 patients (92%) developed grade 2 or more myelosuppression. Ten patients (84%) experienced treatment interruption and 8 patients (67%) required dose reduction. Genetic testing in archival tumor tissue samples failed to identify a predictive biomarker of disease stabilization. The combination of ribociclib and everolimus had insufficient activity to warrant further investigation in foregut WDNETs.

The oncogene AAMDC links PI3K-AKT-mTOR signaling with metabolic reprograming in estrogen receptor-positive breast cancer

Adipogenesis associated Mth938 domain containing (AAMDC) represents an uncharacterized oncogene amplified in aggressive estrogen receptor-positive breast cancers. We uncover that AAMDC regulates the expression of several metabolic enzymes involved in the one-carbon folate and methionine cycles, and lipid metabolism. We show that AAMDC controls PI3K-AKT-mTOR signaling, regulating the translation of ATF4 and MYC and modulating the transcriptional activity of AAMDC-dependent promoters. High AAMDC expression is associated with sensitization to dactolisib and everolimus, and these PI3K-mTOR inhibitors exhibit synergistic interactions with anti-estrogens in IntClust2 models. Ectopic AAMDC expression is sufficient to activate AKT signaling, resulting in estrogen-independent tumor growth. Thus, AAMDC-overexpressing tumors may be sensitive to PI3K-mTORC1 blockers in combination with anti-estrogens. Lastly, we provide evidence that AAMDC can interact with the RabGTPase-activating protein RabGAP1L, and that AAMDC, RabGAP1L, and Rab7a colocalize in endolysosomes. The discovery of the RabGAP1L-AAMDC assembly platform provides insights for the design of selective blockers to target malignancies having the AAMDC amplification.