scholarly journals Hormone Therapy plus mTOR Inhibitors in the Treatment of Endometrial Carcinoma

2010 ◽  
Vol 9 (1) ◽  
pp. 18
Author(s):  
Erica M Stringer ◽  
Gini F Fleming ◽  
◽  
Keyword(s):  
Endometrial Cancer ◽  
Hormonal Therapy ◽  
Single Agent ◽  
Mammalian Target Of Rapamycin ◽  
Hormonal Treatment ◽  
Mtor Inhibitors ◽  
Mtor Pathway ◽  
Mtor Inhibition ◽  
Hormonal Therapies ◽  
Progestin Therapy

Hormonal therapies such as progestins have only modest activity in the treatment of advanced endometrial cancer. Mechanisms of resistance to progestin therapy are not well understood. However, activation of the PI3K/AKT/mammalian target of rapamycin (mTOR) pathway has been associated with resistance to hormonal therapy and alterations in components of the PI3K/AKT/mTOR pathway, including inactivating mutations in PTEN, activating mutations in PIK3CA and mutations in PIK3R1, are very common in endometrial carcinomas. mTOR inhibitors, including temsirolimus, everolimus and ridaforolimus, are also known to be active against endometrial cancer, and interest has been stimulated in combinations of hormonal treatment with mTOR inhibitors, as both therapies have single-agent activity, and it is hypothesised that mTOR inhibition would enhance sensitivity to hormonal therapy.

scholarly journals Hormone Therapy plus mTOR Inhibitors in the Treatment of Endometrial Carcinoma

2013 ◽  
Vol 09 (01) ◽  
pp. 41 ◽  
Author(s):  
Erica M Stringer ◽  
Gini F Fleming ◽  
◽  
Keyword(s):  
Endometrial Cancer ◽  
Hormonal Therapy ◽  
Single Agent ◽  
Hormonal Treatment ◽  
Mtor Inhibitors ◽  
Mtor Pathway ◽  
Mtor Inhibition ◽  
Activating Mutations ◽  
Hormonal Therapies ◽  
Progestin Therapy

Hormonal therapies such as progestins have only modest activity in the treatment of advanced endometrial cancer. Mechanisms of resistance to progestin therapy are not well understood. However, activation of the PI3K/AKT/mTOR pathway has been associated with resistance to hormonal therapy and alterations in components of the PI3K/AKT/mTOR pathway, including inactivating mutations in PTEN, activating mutations in PIK3CA, and mutations in PIK3R1, are very common in endometrial carcinomas. mTOR inhibitors, including temsirolimus, everolimus, and ridaforolimus, are also known to be active against endometrial cancer, and interest has been stimulated in combinations of hormonal treatment with mTOR inhibitors, as both therapies have single-agent activity, and it is hypothesized that mTOR inhibition would enhance sensitivity to hormonal therapy.

Mammalian target of rapamycin (mTOR) pathway signalling in lymphomas

2008 ◽  
Vol 10 ◽  
Author(s):  
Elias Drakos ◽  
George Z. Rassidakis ◽  
L. Jeffrey Medeiros
Keyword(s):  
Mammalian Target Of Rapamycin ◽  
Central Element ◽  
Mtor Inhibitors ◽  
Chemotherapeutic Agents ◽  
Mtor Pathway ◽  
Target Of Rapamycin ◽  
In Vivo Studies ◽  
Mtor Inhibition

AbstractThe mammalian target of rapamycin mTOR is a central element in an evolutionary conserved signalling pathway that regulates cell growth, survival and proliferation, orchestrating signals originating from growth factors, nutrients or particular stress stimuli. Two important modulators of mTOR activity are the AKT and ERK/MAPK signalling pathways. Many studies have shown that mTOR plays an important role in the biology of malignant cells, including deregulation of the cell cycle, inactivation of apoptotic machinery and resistance to chemotherapeutic agents. The development of several mTOR inhibitors, in addition to rapamycin, has facilitated studies of the role of mTOR in cancer, and verified the antitumour effect of mTOR inhibition in many types of neoplasms, including lymphomas. Clinical trials of rapamycin derivatives in lymphoma patients are already in development and there are encouraging preliminary results, such as the substantial response of a subset of mantle cell lymphoma patients to the rapamycin analogue temsirolimus. Based on results obtained from in vitro and in vivo studies of the mTOR pathway in lymphomas, it seems that better understanding of mTOR regulation will reveal aspects of lymphomagenesis and contribute to the development of more powerful, targeted therapies for lymphoma patients.

scholarly journals The Search Continues: Looking for Predictive Biomarkers for Response to Mammalian Target of Rapamycin Inhibition in Endometrial Cancer

2014 ◽  
Vol 24 (4) ◽  
pp. 713-717 ◽  
Author(s):  
Larissa A. Meyer ◽  
Brian M. Slomovitz ◽  
Bojana Djordjevic ◽  
Shannon N. Westin ◽  
David A. Iglesias ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Confidence Interval ◽  
Clinical Benefit ◽  
Objective Response ◽  
Mammalian Target Of Rapamycin ◽  
Mtor Inhibitors ◽  
Mtor Pathway ◽  
Response To Therapy ◽  
Pten Expression ◽  
Target Of Rapamycin

ObjectivePI3K/mammalian target of rapamycin (mTOR) pathway aberrations occur in 40% to 80% of endometrial cancer. Prior studies suggest KRAS mutations are associated with resistance to mTOR inhibitors in solid tumors. The objective of this study was to determine if biomarker expression in the PI3K/mTOR pathway or KRAS mutations would predict response to therapy with everolimus, an mTOR inhibitor.MethodsSpecimens from a phase II study of everolimus in recurrent endometrioid endometrial cancer were utilized. The primary end point was clinical benefit rate (CBR: objective response and nonprogression at 20 weeks). Correlative studies evaluating PTEN expression and phospho-S6 ribosomal protein (pS6rp) status by immunohistochemistry and KRAS mutational analysis were performed.ResultsSix of 28 evaluable patients achieved prolonged stable disease (SD) at 20 weeks (CBR, 21%). Loss of PTEN expression did not predict CBR (P = 0.62) with a positive predictive value (PPV) of 0.13. Five (83%) of 6 patients with SD maintained PTEN expression. Neither pS6rp expression (P = 0.65) nor KRAS mutation (P = 0.99) predicted CBR; the PPV was 0.14 for each. Eighty percent (4/5) of those with SD were KRAS wild type. Combined analysis of pS6rp expression and KRAS mutation provided 100% PPV (95% confidence interval, 39.6%–100%), suggesting no chance of CBR for these individuals with 100% specificity (95% confidence interval, 46.3%–100%).ConclusionsS6rp phosphorylation, loss of PTEN expression, and presence of KRAS mutations alone did not correlate with CBR. However, positive pS6rp staining combined with KRAS mutation performed with 100% PPV and specificity to predict nonresponse. Identifying patients who will not benefit from mTOR inhibitors can direct therapy and reduce exposure to agents that add toxicity without clinical benefit.

scholarly journals Mammalian target of rapamycin signaling activation patterns in neuroendocrine tumors of the lung

2010 ◽  
Vol 17 (4) ◽  
pp. 977-987 ◽  
Author(s):  
Luisella Righi ◽  
Marco Volante ◽  
Ida Rapa ◽  
Veronica Tavaglione ◽  
Frediano Inzani ◽  
...  
Keyword(s):  
Neuroendocrine Tumors ◽  
Mammalian Target Of Rapamycin ◽  
Mtor Pathway ◽  
Differential Sensitivity ◽  
Initiation Factor ◽  
Target Of Rapamycin ◽  
Low Grade ◽  
Mtor Inhibition ◽  
Signaling Activation ◽  
Activation Status

Among alternative therapeutic strategies in clinically aggressive neuroendocrine tumors (NETs) of the lung, promising results have been obtained in experimental clinical trials with mammalian target of rapamycin (mTOR) inhibitors, though in the absence of a proven mTOR signaling activation status. This study analyzed the expression of phosphorylated mTOR (p-mTOR) and its major targets, the ribosomal p70S6-kinase (S6K) and the eukaryotic initiation factor 4E-binding protein 1 (4EBP1) in a large series of 218 surgically resected, malignant lung NETs, including 24 metastasizing typical carcinoids, 73 atypical carcinoids, 60 large cell neuroendocrine carcinomas (LCNECs), and 61 small cell carcinomas (SCLCs). By immunohistochemistry, low-to-intermediate-grade tumors as compared with high-grade tumors showed higher levels of p-mTOR and phosphorylated S6K (p-S6K) (P<0.001), at variance with phosphorylated 4EBP1 (p-4EBP1), which was mainly expressed in LCNECs and SCLCs (P<0.001). The activated status of mTOR pathway was proved by the strong correlation of p-mTOR with p-S6K and somatostatin receptor(s). Western blot analysis of NET tumor samples confirmed such findings, and differential sensitivity to mTOR inhibition according to mTOR pathway activation characteristics was determined in two lung carcinoid cell lines in vitro. None of the investigated molecules had an impact on survival. However, in low-grade tumors, low p-mTOR expression correlated with lymph node metastases (P=0.016), recurrent disease, and survival (P=0.005). In conclusion, these data demonstrate a differential mTOR activation status in the spectrum of pulmonary NETs, possibly suggesting that mTOR pathway profiling might play a predictive role in candidate patients for mTOR-targeted therapies.

scholarly journals mTOR inhibitors lower an intrinsic barrier to virus infection mediated by IFITM3

2018 ◽  
Vol 115 (43) ◽  
pp. E10069-E10078 ◽  
Author(s):  
Guoli Shi ◽  
Stosh Ozog ◽  
Bruce E. Torbett ◽  
Alex A. Compton
Keyword(s):  
Influenza A ◽  
Lentiviral Vector ◽  
Sendai Virus ◽  
Mammalian Target Of Rapamycin ◽  
Mtor Inhibitors ◽  
Endosomal Trafficking ◽  
Mtor Inhibition ◽  
Rapamycin Treatment ◽  
Endosomal Sorting ◽  
Basal Expression

Rapamycin and its derivatives are specific inhibitors of mammalian target of rapamycin (mTOR) kinase and, as a result, are well-established immunosuppressants and antitumorigenic agents. Additionally, this class of drug promotes gene delivery by facilitating lentiviral vector entry into cells, revealing its potential to improve gene therapy efforts. However, the precise mechanism was unknown. Here, we report that mTOR inhibitor treatment results in down-regulation of the IFN-induced transmembrane (IFITM) proteins. IFITM proteins, especially IFITM3, are potent inhibitors of virus–cell fusion and are broadly active against a range of pathogenic viruses. We found that the effect of rapamycin treatment on lentiviral transduction is diminished upon IFITM silencing or knockout in primary and transformed cells, and the extent of transduction enhancement depends on basal expression of IFITM proteins, with a major contribution from IFITM3. The effect of rapamycin treatment on IFITM3 manifests at the level of protein, but not mRNA, and is selective, as many other endosome-associated transmembrane proteins are unaffected. Rapamycin-mediated degradation of IFITM3 requires endosomal trafficking, ubiquitination, endosomal sorting complex required for transport (ESCRT) machinery, and lysosomal acidification. Since IFITM proteins exhibit broad antiviral activity, we show that mTOR inhibition also promotes infection by another IFITM-sensitive virus, Influenza A virus, but not infection by Sendai virus, which is IFITM-resistant. Our results identify the molecular basis by which mTOR inhibitors enhance virus entry into cells and reveal a previously unrecognized immunosuppressive feature of these clinically important drugs. In addition, this study uncovers a functional convergence between the mTOR pathway and IFITM proteins at endolysosomal membranes.

scholarly journals Oral mTOR Inhibitor Everolimus in Patients With Gemcitabine-Refractory Metastatic Pancreatic Cancer

2009 ◽  
Vol 27 (2) ◽  
pp. 193-198 ◽  
Author(s):  
Brian M. Wolpin ◽  
Aram F. Hezel ◽  
Thomas Abrams ◽  
Lawrence S. Blaszkowsky ◽  
Jeffrey A. Meyerhardt ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Adverse Events ◽  
Single Agent ◽  
Progression Free Survival ◽  
Mtor Inhibitors ◽  
Mtor Pathway ◽  
Metastatic Pancreatic Cancer ◽  
Clinical Activity ◽  
Antitumor Effects ◽  
Gemcitabine Refractory

PurposeThe PI3K/Akt/mTOR pathway is activated in the majority of pancreatic cancers, and inhibition of this pathway has antitumor effects in preclinical studies. We performed a multi-institutional, single-arm, phase II study of RAD001(everolimus), an oral inhibitor of mTOR, in patients who experienced treatment failure on first-line therapy with gemcitabine.Patients and MethodsThirty-three patients with gemcitabine-refractory, metastatic pancreatic cancer were treated continuously with RAD001 at 10 mg daily. Prior treatment with fluorouracil in the perioperative setting was allowed. Patients were observed for toxicity, treatment response, and survival.ResultsTreatment with single-agent RAD001 was well-tolerated; the most common adverse events were mild hyperglycemia and thrombocytopenia. No patients were removed from the study because of drug-related adverse events. No complete or partial treatment responses were noted, and only seven patients (21%) had stable disease at the first restaging scans performed at 2 months. Median progression-free survival and overall survival were 1.8 months and 4.5 months, respectively. One patient (3%) had a biochemical response, defined as ≥ 50% reduction in serum CA19-9.ConclusionAlthough well-tolerated, RAD001 administered as a single-agent had minimal clinical activity in patients with gemcitabine-refractory, metastatic pancreatic cancer. Future studies in metastatic pancreatic cancer should assess the combination of mTOR inhibitors with other agents and/or examine inhibitors of other components of the PI3K/Akt/mTOR pathway.

Blocking the mTOR pathway: a drug discovery perspective

2011 ◽  
Vol 39 (2) ◽  
pp. 451-455 ◽  
Author(s):  
Carlos Garcia-Echeverria
Keyword(s):  
Drug Discovery ◽  
Cancer Patients ◽  
Cancer Biology ◽  
Human Cancer ◽  
Mammalian Target Of Rapamycin ◽  
Mtor Inhibitors ◽  
Mechanisms Of Action ◽  
Mtor Pathway ◽  
Lipid Kinase ◽  
Phosphoinositide 3 Kinase

Substantial drug discovery efforts have been devoted, over the last few years, to identifying and developing mTOR (mammalian target of rapamycin) kinase modulators. This has resulted in a number of mTOR inhibitors with different mechanisms of action and/or distinct protein and lipid kinase selectivity profiles. As briefly reviewed in the present paper, these compounds have provided us with a better understanding of the roles of mTOR and other phosphoinositide 3-kinase/mTOR pathway components in human cancer biology, and a few of them have already demonstrated clinical benefit in cancer patients.

scholarly journals Targeting AKT/mTOR in Oral Cancer: Mechanisms and Advances in Clinical Trials

2020 ◽  
Vol 21 (9) ◽  
pp. 3285 ◽  
Author(s):  
Choudhary Harsha ◽  
Kishore Banik ◽  
Hui Li Ang ◽  
Sosmitha Girisa ◽  
Rajesh Vikkurthi ◽  
...  
Keyword(s):  
Oral Cancer ◽  
Epithelial To Mesenchymal Transition ◽  
Mammalian Target Of Rapamycin ◽  
Mtor Inhibitors ◽  
Mtor Pathway ◽  
Mtor Signaling ◽  
Therapeutic Interventions ◽  
Treatment Modalities ◽  
Disease Heterogeneity ◽  
Mesenchymal Transition

Oral cancer (OC) is a devastating disease that takes the lives of lots of people globally every year. The current spectrum of treatment modalities does not meet the needs of the patients. The disease heterogeneity demands personalized medicine or targeted therapies. Therefore, there is an urgent need to identify potential targets for the treatment of OC. Abundant evidence has suggested that the components of the protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) pathway are intrinsic factors for carcinogenesis. The AKT protein is central to the proliferation and survival of normal and cancer cells, and its downstream protein, mTOR, also plays an indispensable role in the cellular processes. The wide involvement of the AKT/mTOR pathway has been noted in oral squamous cell carcinoma (OSCC). This axis significantly regulates the various hallmarks of cancer, like proliferation, survival, angiogenesis, invasion, metastasis, autophagy, and epithelial-to-mesenchymal transition (EMT). Activated AKT/mTOR signaling is also associated with circadian signaling, chemoresistance and radio-resistance in OC cells. Several miRNAs, circRNAs and lncRNAs also modulate this pathway. The association of this axis with the process of tumorigenesis has culminated in the identification of its specific inhibitors for the prevention and treatment of OC. In this review, we discussed the significance of AKT/mTOR signaling in OC and its potential as a therapeutic target for the management of OC. This article also provided an update on several AKT/mTOR inhibitors that emerged as promising candidates for therapeutic interventions against OC/head and neck cancer (HNC) in clinical studies.

scholarly journals Phase II Study of Temsirolimus in Women With Recurrent or Metastatic Endometrial Cancer: A Trial of the NCIC Clinical Trials Group

2011 ◽  
Vol 29 (24) ◽  
pp. 3278-3285 ◽  
Author(s):  
Amit M. Oza ◽  
Laurie Elit ◽  
Ming-Sound Tsao ◽  
Suzanne Kamel-Reid ◽  
Jim Biagi ◽  
...  
Keyword(s):  
Endometrial Cancer ◽  
Partial Response ◽  
Phase Ii ◽  
Median Duration ◽  
Stable Disease ◽  
Mutational Analysis ◽  
Single Agent ◽  
Protein Translation ◽  
Mtor Inhibition ◽  
Phase Ii Studies

Purpose Phosphatase and tensin homolog (PTEN) is a tumor suppressor gene, and loss of function mutations are common and appear to be important in the pathogenesis of endometrial carcinomas. Loss of PTEN causes deregulated phosphatidylinositol-3 kinase/serine-threonine kinase/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling which may provide neoplastic cells with a selective survival advantage by enhancing angiogenesis, protein translation, and cell cycle progression. Temsirolimus, an ester derivative of rapamycin that inhibits mTOR, was evaluated in this setting. Patients and Methods Sequential phase II studies evaluated single-agent activity of temsirolimus in women with recurrent or metastatic chemotherapy-naive or chemotherapy-treated endometrial cancer. Temsirolimus 25 mg intravenously was administered weekly in 4-week cycles. Results In the chemotherapy-naive group, 33 patients received a median of four cycles (range, one to 23 cycles). Of the 29 patients evaluable for response, four (14%) had an independently confirmed partial response and 20 (69%) had stable disease as best response, with a median duration of 5.1 months (range, 3.7 to 18.4 months) and 9.7 months (range, 2.1 to 14.6 months). Only five patients (18%) had progressive disease. In the chemotherapy-treated group, 27 patients received a median of three cycles (range, one to six cycles). Of the 25 patients evaluable for response, one (4%) had an independently confirmed partial response, and 12 patients (48%) had stable disease, with a median duration of 4.3 months (range, 3.6 to 4.9 months) and 3.7 months (range, 2.4 to 23.2 months). PTEN loss (immunohistochemistry and mutational analysis) and molecular markers of PI3K/Akt/mTOR pathway did not correlate with the clinical outcome. Conclusion mTOR inhibition with temsirolimus has encouraging single-agent activity in endometrial cancer which is higher in chemotherapy-naive patients than in chemotherapy-treated patients and is independent of PTEN status. The difference in activity according to prior therapy should be factored into future clinical trial designs.

mTOR Inhibition for Relapsed or Refractory Hodgkin Lymphoma: Promising Single Agent Activity with Everolimus (RAD001).

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2555-2555 ◽  
Author(s):  
Patrick B. Johnston ◽  
Steven M. Ansell ◽  
Joseph P. Colgan ◽  
Thomas M. Habermann ◽  
David J. Inwards ◽  
...  
Keyword(s):  
Hodgkin Lymphoma ◽  
Phase Ii ◽  
Response Rate ◽  
Single Agent ◽  
Mtor Inhibitors ◽  
Cell Transplant ◽  
Mtor Inhibition ◽  
Treatment Regimens ◽  
Common Grade ◽  
Grade 3

Abstract Background: mTOR inhibition has produced responses in mantle cell lymphoma as well as other non-Hodgkin lymphomas. This phase II study tested the oral mTOR inhibitor everolimus (RAD001, Novartis Pharmaceuticals) in simultaneous two-stage phase II lymphoma studies, including one arm involving Hodgkin lymphoma. The goals were to learn the toxicity profile and to assess the anti-tumor response. A total of 17 patients with Hodgkin lymphoma were enrolled in the uncommon arm at completion of enrollment. Methods: Patients (pts) received 10 mg PO daily for each 28 day cycle (up to 12, with a possible extension in responders) and restaged after 2, 6, and 12 cycles. The primary endpoint is the confirmed response rate, including CR, CRu or PR. Results: The median age of the 17 pts with Hodgkin lymphoma was 37 yrs (range: 27–68), with a median of 6 (range, 4–14) prior therapies. Fourteen pts (82.4%) had a prior stem cell transplant (SCT). Pts completed a median of 6 (range, 1–13) cycles of therapy. Fifteen of 17 patients were evaluable for response as of this analysis. The overall response rate was 47% (7/15), all partial responses. Ten patients are continuing on study while 6 have gone off due to disease progression and 1 due to other reasons. Common grade 3 adverse events (AEs) include thrombocytopenia (5 pts), anemia (5 pts) and alkaline phosphatase elevation (1 pts). 1 patient was reported to have grade 4 neutropenia. Conclusions: Oral everolimus has promising activity with acceptable toxicity in Hodgkin lymphoma. These results provide the rationale for additional studies with this novel class of agents and to integrate mTOR inhibitors into salvage treatment regimens for Hodgkin lymphoma.

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