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Frontiers in Oncology 2014The phosphatidylinositol-3-kinase (PI3K)/Akt and the mammalian target of rapamycin (mTOR) signaling pathways are two pathways crucial to many aspects of cell growth and... (Review)
Review
The phosphatidylinositol-3-kinase (PI3K)/Akt and the mammalian target of rapamycin (mTOR) signaling pathways are two pathways crucial to many aspects of cell growth and survival, in physiological as well as in pathological conditions (e.g., cancer). Indeed, they are so interconnected that, in a certain sense, they could be regarded as a single, unique pathway. In this paper, after a general overview of the biological significance and the main components of these pathways, we address the present status of the development of specific PI3K, Akt, and mTOR inhibitors, from already registered medicines to novel compounds that are just leaving the laboratory bench.
PubMed: 24782981
DOI: 10.3389/fonc.2014.00064 -
The Journal of Clinical Investigation Dec 2022Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in immunocompromised individuals is associated with prolonged virus shedding and evolution of...
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in immunocompromised individuals is associated with prolonged virus shedding and evolution of viral variants. Rapamycin and its analogs (rapalogs, including everolimus, temsirolimus, and ridaforolimus) are FDA approved as mTOR inhibitors for the treatment of human diseases, including cancer and autoimmunity. Rapalog use is commonly associated with an increased susceptibility to infection, which has been traditionally explained by impaired adaptive immunity. Here, we show that exposure to rapalogs increased susceptibility to SARS-CoV-2 infection in tissue culture and in immunologically naive rodents by antagonizing the cell-intrinsic immune response. We identified 1 rapalog (ridaforolimus) that was less potent in this regard and demonstrated that rapalogs promote spike-mediated entry into cells, by triggering the degradation of the antiviral proteins IFITM2 and IFITM3 via an endolysosomal remodeling program called microautophagy. Rapalogs that increased virus entry inhibited mTOR-mediated phosphorylation of the transcription factor TFEB, which facilitated its nuclear translocation and triggered microautophagy. In rodent models of infection, injection of rapamycin prior to and after virus exposure resulted in elevated SARS-CoV-2 replication and exacerbated viral disease, while ridaforolimus had milder effects. Overall, our findings indicate that preexisting use of certain rapalogs may elevate host susceptibility to SARS-CoV-2 infection and disease by activating lysosome-mediated suppression of intrinsic immunity.
Topics: Humans; SARS-CoV-2; MTOR Inhibitors; Virus Internalization; COVID-19; Sirolimus; Immunity, Innate; Membrane Proteins; RNA-Binding Proteins
PubMed: 36264642
DOI: 10.1172/JCI160766 -
BMC Research Notes Nov 2014Curative treatments for patients with metastatic synovial sarcoma (SS) do not exist, and such patients have a poor prognosis. We explored combinations of...
BACKGROUND
Curative treatments for patients with metastatic synovial sarcoma (SS) do not exist, and such patients have a poor prognosis. We explored combinations of molecularly-targeted and cytotoxic agents to identify synergistic treatment combinations in SS cells.
METHODS
Two SS cell lines (HS-SY-II and SYO-I) were treated with single agents or combinations of molecularly targeted therapies (HDAC inhibitor, vorinostat; mTOR inhibitor, ridaforolimus) and cytotoxic agents. After 72 hours, cell viability was measured using the MTS cell proliferation assay. Combination Indices (CI) were calculated to determine whether each combination was synergistic, additive, or antagonistic. Western Blot analysis assessed alterations in total and phospho-AKT protein levels in response to drug treatment.
RESULTS
We determined the single-agent IC50 for ridaforolimus, vorinostat, doxorubicin, and melphalan in HS-SY-II and SYO-I. Synergism was apparent in cells co-treated with ridaforolimus and vorinostat: CI was 0.28 and 0.63 in HS-SY-II and SYO-I, respectively. Ridaforolimus/doxorubicin and ridaforolimus/melphalan exhibited synergism in both cell lines. An additive effect was observed with combination of vorinostat/doxorubicin in both cell lines. Vorinostat/melphalan was synergistic in HS-SY-II and additive in SYO-I. Western blot analysis demonstrated that ridaforolimus increased pAKT-ser473 levels; this effect was abrogated by vorinostat co-treatment.
CONCLUSIONS
The combination of ridaforolimus and vorinostat demonstrates in vitro synergism in SS. Addition of vorinostat abrogated ridaforolimus-induced AKT activation. Since AKT activation is a possible mechanism of resistance to mTOR inhibitors, adding vorinostat (or another HDAC inhibitor) may be a route to circumvent AKT-mediated resistance to mTOR inhibitors.
Topics: Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Doxorubicin; Drug Synergism; Enzyme Activation; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Inhibitory Concentration 50; Melphalan; Molecular Targeted Therapy; Phosphorylation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Sarcoma, Synovial; Sirolimus; TOR Serine-Threonine Kinases; Vorinostat
PubMed: 25406429
DOI: 10.1186/1756-0500-7-812 -
Gerontology 2023Rapamycin (sirolimus) is an immunosuppressive drug approved by the Food and Drug Administration (FDA). It is also a leading candidate for targeting aging. Rapamycin and...
Rapamycin (sirolimus) is an immunosuppressive drug approved by the Food and Drug Administration (FDA). It is also a leading candidate for targeting aging. Rapamycin and its analogs (everolimus, temsirolimus, ridaforolimus) inhibit the mammalian target of rapamycin (mTOR) kinase by binding to FK506-binding proteins (FKBP) and have a similar chemical structure that only differs in the functional group present at carbon-40. Analogs of rapamycin were developed to improve its pharmacological properties, such as low oral bioavailability and a long half-life. The analogs of rapamycin are referred to as "rapalogs." Rapamycin is the parent compound and should therewith not be called a "rapalog."
Topics: Humans; MTOR Inhibitors; Sirolimus; Immunosuppressive Agents; Everolimus
PubMed: 36617414
DOI: 10.1159/000528985 -
Drugs in R&D 2010Ridaforolimus (AP23573; MK 8669) is an analog of sirolimus and a small molecule inhibitor of the mammalian target of rapamycin for the treatment of cancer. Both... (Review)
Review
Ridaforolimus (AP23573; MK 8669) is an analog of sirolimus and a small molecule inhibitor of the mammalian target of rapamycin for the treatment of cancer. Both intravenous and oral formulations of the compound are being tested in clinical trials for the treatment of soft-tissue and bone sarcomas. It is in phase III development for sarcoma in the EU and US, and phase II for breast cancer, endometrial cancer, non-small cell lung cancer, and prostate cancer in the US and other markets in the world. This review discusses the key development milestones and therapeutic trials of this drug.
Topics: Animals; Antineoplastic Agents; Clinical Trials as Topic; Drug Screening Assays, Antitumor; Drugs, Investigational; Humans; Neoplasms; Sirolimus; TOR Serine-Threonine Kinases
PubMed: 20945947
DOI: 10.2165/11586010-000000000-00000 -
Proceedings of the National Academy of... Sep 2021Bladder cancer (BC) has a 70% telomerase reverse transcriptase (TERT or hTERT in humans) promoter mutation prevalence, commonly at -124 base pairs, and this is...
Bladder cancer (BC) has a 70% telomerase reverse transcriptase (TERT or hTERT in humans) promoter mutation prevalence, commonly at -124 base pairs, and this is associated with increased hTERT expression and poor patient prognosis. We inserted a green fluorescent protein (GFP) tag in the mutant hTERT promoter allele to create BC cells expressing an hTERT-GFP fusion protein. These cells were used in a fluorescence-activated cell sorting-based pooled CRISPR-Cas9 Kinome knockout genetic screen to identify tripartite motif containing 28 (TRIM28) and TRIM24 as regulators of hTERT expression. TRIM28 activates, while TRIM24 suppresses, hTERT transcription from the mutated promoter allele. TRIM28 is recruited to the mutant promoter where it interacts with TRIM24, which inhibits its activity. Phosphorylation of TRIM28 through the mTOR complex 1 (mTORC1) releases it from TRIM24 and induces hTERT transcription. TRIM28 expression promotes in vitro and in vivo BC cell growth and stratifies BC patient outcome. mTORC1 inhibition with rapamycin analog Ridaforolimus suppresses TRIM28 phosphorylation, hTERT expression, and cell viability. This study may lead to hTERT-directed cancer therapies with reduced effects on normal progenitor cells.
Topics: Cell Line, Tumor; Cell Proliferation; Cell Survival; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Mutation; Promoter Regions, Genetic; Stem Cells; Telomerase; Transcription Factors; Transcription, Genetic; Tripartite Motif-Containing Protein 28; Urinary Bladder Neoplasms
PubMed: 34518220
DOI: 10.1073/pnas.2102423118 -
JACC. Cardiovascular Interventions Jan 2020This study sought to determine clinical outcomes between treatment groups over long-term follow-up.
OBJECTIVES
This study sought to determine clinical outcomes between treatment groups over long-term follow-up.
BACKGROUND
The safety and efficacy of a ridaforolimus-eluting stent (RES) was evaluated in the BIONICS (BioNIR Ridaforolimus-Eluting Coronary Stent System in Coronary Stenosis) and NIREUS (BioNIR Ridaforolimus Eluting Coronary Stent System [BioNIR] European Angiography Study) trials, demonstrating noninferiority of RES in comparison with a zotarolimus-eluting stent (ZES) regarding 1-year target lesion failure (TLF) and 6-month angiographic late lumen loss, respectively.
METHODS
Patient-level data from the BIONICS (N = 1,919) and NIREUS (N = 302) randomized trials were pooled, and outcomes in patients implanted with RES and ZES compared. Broad inclusion criteria allowed enrollment of patients with acute coronary syndromes and complex lesions. The primary endpoint was the 2-year rate of TLF or clinically driven target lesion revascularization.
RESULTS
A total of 2,221 patients (age 63.2 ± 10.3 years; 79.7% men) undergoing percutaneous coronary intervention with RES (n = 1,159) or ZES (n = 1,062) were included. Clinical and angiographic characteristics were similar between groups. At 2 years, the primary endpoint of TLF was similar among patients implanted with RES and ZES (7.0% vs. 7.2%; p = 0.94). Rates of target lesion revascularization (4.8% RES vs. 4.1% ZES; p = 0.41) and target vessel-related myocardial infarction (3.1% RES vs. 3.8% ZES; p = 0.52) did not differ between groups. The overall rate of stent thrombosis was also similar (0.5% RES vs. 0.9% ZES; p = 0.39).
CONCLUSIONS
In a pooled analysis of 2 randomized trials, 2-year clinical outcomes were similar between patients undergoing percutaneous coronary intervention with RES and ZES. These results support the long-term safety and efficacy of RES for the treatment of a broad population of patients with coronary artery disease.
Topics: Aged; Cardiovascular Agents; Coronary Angiography; Coronary Artery Disease; Coronary Thrombosis; Drug-Eluting Stents; Female; Humans; Male; Middle Aged; Myocardial Infarction; Percutaneous Coronary Intervention; Prosthesis Design; Randomized Controlled Trials as Topic; Risk Factors; Sirolimus; Time Factors; Treatment Outcome
PubMed: 31918946
DOI: 10.1016/j.jcin.2019.08.019 -
Frontiers in Pharmacology 2024Rapamycin, an established mTOR inhibitor in clinical practice, is widely recognized for its therapeutic efficacy. Ridaforolimus, a non-prodrug rapalog, offers improved... (Review)
Review
Rapamycin, an established mTOR inhibitor in clinical practice, is widely recognized for its therapeutic efficacy. Ridaforolimus, a non-prodrug rapalog, offers improved aqueous solubility, stability, and affinity compared to rapamycin. In recent years, there has been a surge in clinical trials involving ridaforolimus. We searched PubMed for ridaforolimus over the past decade and selected clinical trials of ridaforolimus to make a summary of the research progress of ridaforolimus in clinical trials. The majority of these trials explored the application of ridaforolimus in treating various tumors, including endometrial cancer, ovarian cancer, prostate cancer, breast cancer, renal cell carcinoma, and other solid tumors. These trials employed diverse drug combinations, incorporating agents such as ponatinib, bicalutamide, dalotuzumab, MK-2206, MK-0752, and taxanes. The outcomes of these trials unveiled the diverse potential applications of ridaforolimus in disease treatment. Our review encompassed analyses of signaling pathways, ridaforolimus as a single therapeutic agent, its compatibility in combination with other drugs, and an assessment of adverse events (AEs). We conclude by recommending further research to advance our understanding of ridaforolimus's clinical applications.
PubMed: 38584599
DOI: 10.3389/fphar.2024.1173240 -
European Journal of Cancer (Oxford,... Sep 2015The phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of rapamycin (PI3K-AKT-mTOR) signalling pathway is aberrantly activated in several cancers. Notch...
BACKGROUND
The phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of rapamycin (PI3K-AKT-mTOR) signalling pathway is aberrantly activated in several cancers. Notch signalling maintains cell proliferation, growth and metabolism in part by driving the PI3K pathway. Combining the mTOR inhibitor ridaforolimus with the Notch inhibitor MK-0752 may increase blockade of the PI3K pathway.
METHODS
This phase I dose-escalation study (NCT01295632) aimed to define the dose-limiting toxicities (DLTs) and maximum tolerated dose (MTD) of combination oral ridaforolimus (rising doses starting at 20 mg, 5 days/week) and oral MK-0752 (1800 mg once weekly) in patients with solid tumours. No intrapatient dose escalation was permitted.
RESULTS
Twenty eight patients were treated on study. Ridaforolimus doses were escalated from 20 to 30 mg/day. Among 14 evaluable patients receiving ridaforolimus 20 mg, one DLT (grade 2 stomatitis, second episode) was reported. Among eight evaluable patients receiving ridaforolimus 30 mg, three DLTs were reported (one each grade 3 stomatitis, grade 3 diarrhoea, and grade 3 asthenia). The MTD was 20 mg daily ridaforolimus 5 days/week+1800 mg weekly MK-0752. The most common drug-related adverse events included stomatitis, diarrhoea, decreased appetite, hyperglycaemia, thrombocytopenia, asthenia and rash. Two of 15 (13%) patients with head and neck squamous cell carcinoma (HNSCC) had responses: one with complete response and one with partial response. In addition, one patient experienced stable disease ⩾6 months.
CONCLUSIONS
Combined ridaforolimus and MK-0752 showed activity in HNSCC. However, a high number of adverse events were reported at the MTD, which would require careful management during future clinical development.
Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Benzene Derivatives; Carcinoma, Squamous Cell; Drug Administration Schedule; Europe; Female; Head and Neck Neoplasms; Humans; Male; Maximum Tolerated Dose; Middle Aged; Molecular Targeted Therapy; Multimodal Imaging; Positron-Emission Tomography; Propionates; Protein Kinase Inhibitors; Signal Transduction; Sirolimus; Squamous Cell Carcinoma of Head and Neck; Sulfones; Time Factors; Tomography, X-Ray Computed; Treatment Outcome; United States
PubMed: 26199039
DOI: 10.1016/j.ejca.2015.06.115 -
Breast Cancer Research and Treatment Jun 2017Combining the mTOR inhibitor ridaforolimus and the anti-IGFR antibody dalotuzumab demonstrated antitumor activity, including partial responses, in estrogen receptor... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
Combining the mTOR inhibitor ridaforolimus and the anti-IGFR antibody dalotuzumab demonstrated antitumor activity, including partial responses, in estrogen receptor (ER)-positive advanced breast cancer, especially in high proliferation tumors (Ki67 > 15%).
METHODS
This randomized, multicenter, international, phase II study enrolled postmenopausal women with advanced ER-positive breast cancer previously treated with a nonsteroidal aromatase inhibitor (NCT01234857). Patients were randomized to either oral ridaforolimus 30 mg daily for 5 of 7 days (once daily [qd] × 5 days/week) plus intravenous dalotuzumab 10 mg/kg/week or oral exemestane 25 mg/day, and stratified by Ki67 status. Due to a high incidence of stomatitis in the ridaforolimus-dalotuzumab group, two sequential, nonrandomized, reduced-dose cohorts were explored with ridaforolimus 20 and 10 mg qd × 5 days/week. The primary endpoint was progression-free survival (PFS).
RESULTS
Median PFS was 21.4 weeks for ridaforolimus 30 mg qd × 5 days/week plus dalotuzumab 10 mg/kg (n = 29) and 24.3 weeks for exemestane (n = 33; hazard ratio = 1.00; P = 0.5). Overall survival and objective response rates were similar between treatment arms. The incidence of drug-related, nonserious, and serious adverse events was higher with ridaforolimus/dalotuzumab (any ridaforolimus dose) than with exemestane. Lowering the ridaforolimus dose reduced the incidence of grade 3 stomatitis, but overall toxicity remained higher than acceptable at all doses without improved efficacy.
CONCLUSIONS
The combination of ridaforolimus plus dalotuzumab was no more effective than exemestane in patients with advanced ER-positive breast cancer, and the incidence of adverse events was higher. Therefore, the combination is not being further pursued.
Topics: Adult; Aged; Androstadienes; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Disease-Free Survival; Female; Humans; Middle Aged; Protein Kinase Inhibitors; Receptors, Estrogen; Sirolimus; Stomatitis
PubMed: 28324268
DOI: 10.1007/s10549-017-4199-3