Drug discovery targeting the mTOR pathway

2018 ◽  
Vol 132 (5) ◽  
pp. 543-568 ◽  
Author(s):  
Alberto M. Martelli ◽  
Francesca Buontempo ◽  
James A. McCubrey
Keyword(s):  
Antitumor Activity ◽  
Human Cancer ◽  
Mtor Inhibitors ◽  
Metastatic Potential ◽  
Current Status ◽  
Oncogenic Signaling ◽  
Metabolic Transformation ◽  
Preclinical And Clinical Studies ◽  
Mtor Complex 1

Mechanistic target of rapamycin (mTOR) is the kinase subunit of two structurally and functionally distinct large multiprotein complexes, referred to as mTOR complex 1 (mTORC1) and mTORC2. mTORC1 and mTORC2 play key physiological roles as they control anabolic and catabolic processes in response to external cues in a variety of tissues and organs. However, mTORC1 and mTORC2 activities are deregulated in widespread human diseases, including cancer. Cancer cells take advantage of mTOR oncogenic signaling to drive their proliferation, survival, metabolic transformation, and metastatic potential. Therefore, mTOR lends itself very well as a therapeutic target for innovative cancer treatment. mTOR was initially identified as the target of the antibiotic rapamycin that displayed remarkable antitumor activity in vitro. Promising preclinical studies using rapamycin and its derivatives (rapalogs) demonstrated efficacy in many human cancer types, hence supporting the launch of numerous clinical trials aimed to evaluate the real effectiveness of mTOR-targeted therapies. However, rapamycin and rapalogs have shown very limited activity in most clinical contexts, also when combined with other drugs. Thus, novel classes of mTOR inhibitors with a stronger antineoplastic potency have been developed. Nevertheless, emerging clinical data suggest that also these novel mTOR-targeting drugs may have a weak antitumor activity. Here, we summarize the current status of available mTOR inhibitors and highlight the most relevant results from both preclinical and clinical studies that have provided valuable insights into both their efficacy and failure.

scholarly journals SYNTHESIS AND ANTITUMOR ACTIVITY OF NEW MULTIFUNCTIONAL COUMARINS

2020 ◽  
Vol 17 (36) ◽  
pp. 871-883
Author(s):  
Moath Kahtan BASHIR ◽  
Yasser Fakri MUSTAFA ◽  
Mahmood Khudhayer OGLAH
Keyword(s):  
Schiff Base ◽  
Antitumor Activity ◽  
Human Cancer ◽  
Biological Activities ◽  
Cell Viability Assay ◽  
Chemical Structures ◽  
Viability Assay ◽  
Schiff Base Formation ◽  
Mcf 7

Cancer constitutes one of the most severe public health menaces worldwide. It is imperative to synthesize new compounds and explore their antitumor activity to find a potential resolution to this health problem. Synthesis of new scaffolds and evaluating their antitumor activity is a relevant approach for combating cancer development. Coumarins can exhibit diverse biological activities, and one of these is the antitumor activity. This study aimed to synthesize new coumarins by grafting their precursors to the aromatic amines via Schiff base formation and evaluating their introductory antitumor activity. New multifunctional coumarins (MC1-MC9) were prepared by integrating a functionalized coumarin with different toluidine derivatives via a Schiff-base linkage. Spectral characterization inspired by FTIR, 1H- and 13C- NMR spectroscopies has established the chemical structures of the synthesized products. The antitumor activity was explored in vitro versus four dominant human cancer lines, including HeLa, SKG, MCF-7, and AMN3. The outcomes acquired from the cell viability assay inspected by applying MTT dye have revealed that the synthesized multifunctional coumarins, particularly MC3, have a hopeful activity. It can be concluded that a similar trend of activity against the test cell lines was observed for the synthesized coumarins, with the best action being versus MCF-7 and the least one versus AMN3. This study not only affords a new scaffold of a significant antitumor activity but also provides some insights into its structureactivity relationship.

scholarly journals Chloroquine Urea Derivatives: Synthesis and Antitumor Activity in Vitro

2018 ◽  
Vol 68 (4) ◽  
pp. 471-483 ◽  
Author(s):  
Kristina Pavić ◽  
Zrinka Rajić ◽  
Zvonimir Mlinarić ◽  
Lidija Uzelac ◽  
Marijeta Kralj ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Anticancer Agents ◽  
Human Cancer ◽  
Human Cancer Cell ◽  
Urea Derivatives ◽  
Design Synthesis ◽  
Human Cancer Cell Lines ◽  
Lead Compounds ◽  
Insight Into

Abstract In the current paper, we describe the design, synthesis and antiproliferative screening of novel chloroquine derivatives with a quinoline core linked to a hydroxy or halogen amine through a flexible aminobutyl chain and urea spacer. Synthetic pathway leading to chloroquine urea derivatives 4-10 includes two crucial steps: i) synthesis of chloroquine benzotriazolide 3 and ii) formation of urea derivatives through the reaction of compound 3 with the corresponding amine. Testing of antiproliferative activity against four human cancer cell lines revealed that chloroquine urea derivatives 9 and 10 with aromatic moieties show activity at micromolar concentrations. Therefore, these molecules represent interesting lead compounds that might provide an insight into the design of new anticancer agents.

scholarly journals MAP Kinase inhibition reshapes tumor microenvironment of mouse pancreatic cancer by depleting anti-inflammatory macrophages

2019 ◽  
Author(s):  
Pietro Delfino ◽  
Christian Neander ◽  
Dea Filippini ◽  
Sabrina L. D’Agosto ◽  
Caterina Vicentini ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Antitumor Activity ◽  
Map Kinase ◽  
Ductal Adenocarcinoma ◽  
Oncogenic Signaling ◽  
Kinase Activation ◽  
Immune Contexture ◽  
Inflammatory Macrophages

ABSTRACTThe RAF/MEK/ERK (MAP Kinase) pathway is the index oncogenic signaling towards which many compounds have been developed and tested for the treatment of KRAS-driven cancers, including pancreatic ductal adenocarcinoma (PDA). Here, we explored the immunological changes induced by targeted MEK1/2 inhibition (MEKi) using trametinib in preclinical mouse models of PDA. We evaluated the dynamic changes in the immune contexture of mouse PDA upon MEKi using a multidimensional approach (mRNA analyses, flow cytometry, and immunophenotyping). Effect of MEKi on the viability and metabolism of macrophages was investigated in vitro. We showed that transcriptional signatures of MAP Kinase activation are enriched in aggressive human PDA subtype (squamous/basal-like/quasimesenchymal), while short term MEKi treatment in mouse PDA induced subtype switching. Integrative mRNA expression and immunophenotypic analyses showed that MEKi reshapes the immune landscape of PDA by depleting rather than reprogramming macrophages, while augmenting infiltration by neutrophils. Depletion of macrophages is observed early in the course of in vivo treatment and is at least partially due to their higher sensitivity to MEKi. Tumor-associated macrophages were consistently reported to interfere with gemcitabine uptake by PDA cells. Here, our in vivo studies show a superior antitumor activity upon combination of MEKi and gemcitabine using a sequential rather than simultaneous dosing protocol. Our results show that MEK inhibition induces a dramatic remodeling of the tumor microenvironment of mouse PDA through depletion of macrophages, which substantially improves the antitumor activity of gemcitabine.

scholarly journals Identification of TUBB4A as a Prognostic Biomarker of Melanoma by Transcriptomic Data and in vitro Experiments

2021 ◽  
Author(s):  
Jiaqi Zhang ◽  
Zhe Li ◽  
Hui Liu ◽  
Qi Wu ◽  
Zhiqiang Sun ◽  
...  
Keyword(s):  
Cutaneous Melanoma ◽  
Cell Cycle Progression ◽  
Prognostic Biomarker ◽  
Human Cancer ◽  
Differential Expression Analysis ◽  
Metastatic Potential ◽  
Melanoma Cells ◽  
Normal Tissues ◽  
And Migration

Abstract Background Melanoma is one of the most malignant skin carcinomas with high metastatic potential. Increasing evidences have demonstrated that β-tubulin 4A (TUBB4A) play key role in development and progression of several types of human cancer. However, the potential function of TUBB4A in cutaneous melanoma remains to be determined. Methods We first performed differential expression analysis between skin melanoma tissues and normal tissues from GEO and TCGA datasets, and then ran survival analysis to identify prognostic-related key genes. We went further to conduct the verification of in vitro biochemical experiments to explore the functional roles of key gene TUBB4A. Two small molecule inhibitors of TUBB4A, Dihydroartemisinin (DHA) and Nocodazole, were used to examined the effect on apoptosis and cell cycle progression of melanoma cells. Results We found that TUBB4A is markedly correlated to the overall survival of cutaneous melanoma patients. The co-expressed genes with TUBB4A are enriched in the melanoma-related pathways and function. Then, the experimental results showed that knockdown of TUBB4A inhibit the proliferation and migration of A375 and B16-F10 melanoma cells. Moreover, two small molecular agents targeting TUBB4A, Dihydroartemisinin and Nonocodazole, dpromote the apoptosis of melanoma cells and made the tumor cells significantly blocked in G2/M stage. Conclusion We identified and validated in vitro that TUBB4A may be a prognostic biomarker and therapeutic target for melanoma.

FLT3 and KIT Isoforms Activate PI3K/AKT Signaling Which Is Potently Blocked by the Novel Dual PI3K/Mtor Inhibitors NVP-BEZ235 and NVP-BGT226.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1740-1740 ◽  
Author(s):  
Kerstin M Kampa ◽  
Sandra Mueller ◽  
Katharina-Henriette Rasp ◽  
Lothar Kanz ◽  
Michael C Heinrich ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Cell Line ◽  
Blast Crisis ◽  
Mtor Inhibitors ◽  
Akt Signaling ◽  
Akt Pathway ◽  
Mtor Inhibition ◽  
Escape Mechanism ◽  
Nanomolar Range

Abstract Abstract 1740 Poster Board I-766 In ∼40% of de novo cases of acute myeloid leukemia (AML), autoactivating mutations in the class III receptor tyrosine kinases (RTK) KIT and FLT3 are observed and are closely linked to leukemogenesis. We and others previously demonstrated that leukemia-driving gain-of-function mutations of KIT and FLT3 consecutively activate AKT, MAPK1/2 (ERK1/2) and STAT signalling. We show that global AKT phosphorylation can be detected in AML patients. In contrast, RTK-inhibition only partially blocks PI3K/AKT/p70S6K signaling in our in vitro leukemia models, which suggests the existence of an escape mechanism that is not yet understood. Combination of tyrosine kinase inhibitors (TKI) with rapamycin, a specific MTOR inhibitor acting upstream of p70S6K, potentiates the antitumor activity of TKI. However, we show that upregulation of AKT-phophorylation – possibly by feedback loops – is observed in western blot analysis. In an attempt to globally block AKT signaling we tested the dual PI3K/MTOR inhibitors NVP-BEZ235 and NVP-BGT226 with regard to their antiproliferative and proapoptotic potential in a variety of mutant-KIT/FLT3 leukemia cell lines. Inhibition of PI3K and MTOR phosphorylation sites in the upper nanomolar range consequently lead to dephosphorylation of the threonine 308 as well as the serine 473 AKT phospho-sites - as well as the phospho p70S5kinase phospho-sites with both tested inhibitors. Moreover, global blockage of the PI3K/AKT/MTOR/p70S6K signal transduction pathway translated into a potent antitumor activity on the cellular level - with NVP-BGT226 being the more potent agent in antiproliferation and apoptosis assays with IC50s in the nanomolar range. Moreover, we also tested the blast crisis CML cell line K562 – which also revealed sensitivity towards PI3K/MTOR inhibition in the same dose range. To study the influence of different mutant isoforms of KIT/FLT3 on sensitivity to TKI, we created FLT3, KIT and BCR/ABL transfectants in a Ba/F3 cell line background. Both inhibitors displayed the most profound activity in cells transfected with an autoactivating FLT3 or KIT isoform with IC50s between 250-500 nanomolar. In contrast, the FLT3 wildtype isoform displayed decreased sensitivity towards both inhibitors. No sensitivity to NVP-BEZ235 and NVP-BGT226 was observed in BCR/ABL transfectants and the Ba/F3 parental cell line up to 5-10 micromolar. As expected, combination of the dual PI3K/MTOR inhibitors with TKI (Imatinib, Dasatinib, and Sunitinib) potentiated the antiproliferative and proapoptotic effects observed for the single agents. We conclude that the PI3K/AKT pathway is activated by mutant FLT3 and KIT isoforms - but not by BCR/ABL. In acute leukemias, including CML blast crisis, the PI3K/AKT pathway is further activated due to other yet unknown mechanisms. Thus, the PI3K/AKT pathway may provide an escape mechanism from TKI therapy contributing to the moderate/shorter response rates in acute forms of leukemia (including CML blast crisis) compared to TKI therapy in CML. NVP-BEZ235 and NVP-BGT226 display potent antiproliferative as well as proapoptotic effects in leukemia in vitro models alone and in combination with TKI and warrant clinical evaluation. Disclosures No relevant conflicts of interest to declare.

scholarly journals GHRH antagonists reduce the invasive and metastatic potential of human cancer cell lines in vitro

2010 ◽  
Vol 293 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Szabolcs Bellyei ◽  
Andrew V. Schally ◽  
Marta Zarandi ◽  
Jozsef L. Varga ◽  
Irving Vidaurre ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cancer Cell ◽  
Human Cancer ◽  
Metastatic Potential ◽  
Cancer Cell Lines ◽  
Human Cancer Cell ◽  
Human Cancer Cell Lines ◽  
Ghrh Antagonists

Antitumor activity of enzastaurin (LY317615.HCl) against human cancer cell lines and freshly explanted tumors investigated in vitro soft-agar cloning experiments

2007 ◽  
Vol 25 (3) ◽  
pp. 205-210 ◽  
Author(s):  
Axel-Rainer Hanauske ◽  
Olaf Oberschmidt ◽  
Hartmut Hanauske-Abel ◽  
Michael M. Lahn ◽  
Ulrike Eismann
Keyword(s):  
Antitumor Activity ◽  
Cell Lines ◽  
Cancer Cell ◽  
Human Cancer ◽  
Cancer Cell Lines ◽  
Soft Agar ◽  
Human Cancer Cell ◽  
Human Cancer Cell Lines ◽  
Soft Agar Cloning

scholarly journals ΔNp63α is a common inhibitory target in oncogenic PI3K/Ras/Her2-induced cell motility and tumor metastasis

2017 ◽  
Vol 114 (20) ◽  
pp. E3964-E3973 ◽  
Author(s):  
Linshan Hu ◽  
Shan Liang ◽  
Hu Chen ◽  
Tao Lv ◽  
Junfeng Wu ◽  
...  
Keyword(s):  
Cell Motility ◽  
Tumor Metastasis ◽  
Cancer Metastasis ◽  
Human Cancer ◽  
Critical Role ◽  
Major Protein ◽  
Oncogenic Signaling ◽  
Cancer Biopsy ◽  
Her2 Signaling

Activation of phosphatidylinositol 3 kinase (PI3K), Ras, and Her2 signaling plays a critical role in cancer development. Hotspot constitutive activating mutations in oncogenes, such as PIK3CA encoding the p110α catalytic subunit or RAS, as well as overexpression of Her2, are frequently found in human tumors and cancers. It has been well established that activation of these oncogenes profoundly promotes tumor metastasis, whereas decreased expression of ΔNp63α, the major protein isoform of the p53-related p63 expressed in epithelial cells, has been associated with cancer metastasis. In this study, we demonstrate that hotspot oncogenic mutations on PIK3CA and RAS, including p110αH1047R, K-RasG12V, and H-RasG12V, as well as activation of Her2, all led to suppression of ΔNp63α expression via Akt-fork-head transcription factor 3a (Akt-FOXO3a) signaling, resulting in increased cell motility and tumor metastasis. Expression of ΔNp63α effectively reversed p110αH1047R-, K-RasG12V–, H-RasG12V–, or Her2-induced cell motility in vitro and tumor metastasis in mouse models. We show that ΔNp63α was a direct FOXO3a transcriptional target and that expression of FOXO3a and ΔNp63α was correlated in human cancer biopsy samples. Together, these results demonstrate that ΔNp63α is a common inhibitory target of oncogenic PI3K, Ras, and Her2, and that ΔNp63α may function as a critical integrator of oncogenic signaling in cancer metastasis.

Cellular and molecular effects of the mTOR inhibitor everolimus

2015 ◽  
Vol 129 (10) ◽  
pp. 895-914 ◽  
Author(s):  
Uttara Saran ◽  
Michelangelo Foti ◽  
Jean-François Dufour
Keyword(s):  
Mtor Inhibitor ◽  
Mtor Inhibitors ◽  
Cancer Therapies ◽  
Breast Cancers ◽  
Mtor Inhibition ◽  
Growth And Survival ◽  
Molecular Effects ◽  
Mtor Complex 1

mTOR (mechanistic target of rapamycin) functions as the central regulator for cell proliferation, growth and survival. Up-regulation of proteins regulating mTOR, as well as its downstream targets, has been reported in various cancers. This has promoted the development of anti-cancer therapies targeting mTOR, namely fungal macrolide rapamycin, a naturally occurring mTOR inhibitor, and its analogues (rapalogues). One such rapalogue, everolimus, has been approved in the clinical treatment of renal and breast cancers. Although results have demonstrated that these mTOR inhibitors are effective in attenuating cell growth of cancer cells under in vitro and in vivo conditions, subsequent sporadic response to rapalogues therapy in clinical trials has promoted researchers to look further into the complex understanding of the dynamics of mTOR regulation in the tumour environment. Limitations of these rapalogues include the sensitivity of tumour subsets to mTOR inhibition. Additionally, it is well known that rapamycin and its rapalogues mediate their effects by inhibiting mTORC (mTOR complex) 1, with limited or no effect on mTORC2 activity. The present review summarizes the pre-clinical, clinical and recent discoveries, with emphasis on the cellular and molecular effects of everolimus in cancer therapy.

In vitro and in vivo effects of the mTOR inhibitors everolimus (EVE) and temsirolimus (TEM).

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 466-466
Author(s):  
David Chen ◽  
Michael Terence O'Reilly ◽  
Paul M.J. McSheehy
Keyword(s):  
Cell Proliferation ◽  
Antitumor Activity ◽  
A549 Cells ◽  
Human Tumor ◽  
Mtor Inhibitors ◽  
In Vivo Models ◽  
Hct 116 ◽  
Xenograft Models

466 Background: Two mTOR inhibitors are approved for treating mRCC: EVE following the failure of VEGF-targeted therapy and TEM as first-line therapy in poor-risk patients. Both agents exert their clinical effect by binding to FKBP-12, which then interacts with mTOR to inhibit its kinase activity. We compared the activity of EVE and TEM in in vitro and in vivo models. Methods: EVE and TEM binding to mTOR was assessed using time-resolved fluorescence resonance energy transfer. Inhibition of cell proliferation in A549, NCI-H460, and MCF7 human tumor cell lines was assessed by methylene blue protein staining. Phosphorylation of the downstream mTOR target pS6 was assessed via immunohistochemistry in A549 cells. Antitumor activity of EVE (oral) and TEM (intraperitoneal) at doses between 0.1 and 2.5 mg/kg once daily was assessed in vivo in A549, KB-31, KB-8511, and HCT-116 human tumor xenograft models. Results: The binding efficiency of TEM for mTOR was reduced 10-fold compared with that of EVE (EC50, 56 nM vs 6 nM; p < 0.01). EVE demonstrated 6- to 7-fold greater inhibition of cell proliferation than TEM (IC50, 1.0 nM vs 6.5 nM in A549 [p < 0.001], 0.7 nM vs 4.7 nM in NCI-H460 [p < 0.01], and 19.4 nM vs 150 nM in MCF7 [p < 0.001]). Complete inhibition of pS6 phosphorylation in A549 cells at 24 hours was achieved with 6.7 nM EVE, but required 20 nM TEM. In all xenograft models, EVE and TEM showed a dose-response relationship over the range of 0.1-2.5 mg/kg/day. EVE was significantly more potent than TEM in the A549 model (EC50, 0.11 mg/kg vs 0.51 mg/kg; p = 0.002); no appreciable differences between EVE and TEM were observed in the KB-31, KB-8511, and HCT-116 xenograft models. However, correcting for drug exposure suggests increased potency of EVE over TEM. Conclusions: Compared with TEM, EVE had a higher affinity for the molecular target of FKBP-12. This was consistent with more potent antitumor activity in vitro and in vivo. Whether these data would translate into a better therapeutic index for EVE is unknown. However, the results suggest that these mTOR inhibitors may not be clinically interchangeable.

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