scholarly journals Targeting mTOR in Glioblastoma: Rationale and Preclinical/Clinical Evidence

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Carmen Mecca ◽  
Ileana Giambanco ◽  
Rosario Donato ◽  
Cataldo Arcuri
Keyword(s):  
Therapeutic Strategy ◽  
Molecular Mechanisms ◽  
Clinical Evidence ◽  
Survival Rates ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphatase And Tensin Homolog ◽  
Cellular Processes ◽  
Mechanistic Target Of Rapamycin ◽  
Tensin Homolog ◽  
Different Types

The mechanistic target of rapamycin (mTOR) drives several physiologic and pathologic cellular processes and is frequently deregulated in different types of tumors, including glioblastoma (GBM). Despite recent advancements in understanding the molecular mechanisms involved in GBM biology, the survival rates of this tumor are still disappointing, primarily due to the lack of efficacious treatments. The phosphatase and tensin homolog (PTEN)/phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/mTOR pathway has emerged as a crucial player in GBM development and progression. However, to date, all the attempts to target this pathway with PI3K, AKT, or mTORC1 inhibitors failed to improve the outcome of patients with GBM. Despite these discouraging results, recent evidence pointed out that the blockade of mTORC2 might provide a useful therapeutic strategy for GBM, with the potential to overcome the limitations that mTORC1 inhibitors have shown so far. In this review, we analyzed the rationale of targeting mTOR in GBM and the available preclinical and clinical evidence supporting the choice of this therapeutic approach, highlighting the different roles of mTORC1 and mTORC2 in GBM biology.

scholarly journals Phosphatidylinositol 3-kinase regulatory subunit 1 and phosphatase and tensin homolog as therapeutic targets in breast cancer

Tumor Biology ◽  
2017 ◽  
Vol 39 (3) ◽  
pp. 101042831769552 ◽  
Author(s):  
Ebubekir Dirican ◽  
Mustafa Akkiprik
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Breast Cancer Progression ◽  
Regulatory Subunit ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Kinase Pathway ◽  
Phosphatidylinositol 3

Breast cancer is the most commonly diagnosed cancer among women in Turkey and worldwide. It is considered a heterogeneous disease and has different subtypes. Moreover, breast cancer has different molecular characteristics, behaviors, and responses to treatment. Advances in the understanding of the molecular mechanisms implicated in breast cancer progression have led to the identification of many potential therapeutic gene targets, such as Breast Cancer 1/2, phosphatidylinositol 3-kinase catalytic subunit alpha, and tumor protein 53. The aim of this review is to summarize the roles of phosphatidylinositol 3-kinase regulatory subunit 1 (alpha) (alias p85α) and phosphatase and tensin homolog in breast cancer progression and the molecular mechanisms involved. Phosphatase and tensin homolog is a tumor suppressor gene and protein. Phosphatase and tensin homolog antagonizes the phosphatidylinositol 3-kinase/AKT signaling pathway that plays a key role in cell growth, differentiation, and survival. Loss of phosphatase and tensin homolog expression, detected in about 20%–30% of cases, is known to be one of the most common tumor changes leading to phosphatidylinositol 3-kinase pathway activation in breast cancer. Instead, the regulatory subunit p85α is a significant component of the phosphatidylinositol 3-kinase pathway, and it has been proposed that a reduction in p85α protein would lead to decreased negative regulation of phosphatidylinositol 3-kinase and hyperactivation of the phosphatidylinositol 3-kinase pathway. Phosphatidylinositol 3-kinase regulatory subunit 1 protein has also been reported to be a positive regulator of phosphatase and tensin homolog via the stabilization of this protein. A functional genetic alteration of phosphatidylinositol 3-kinase regulatory subunit 1 that results in reduced p85α protein expression and increased insulin receptor substrate 1 binding would lead to enhanced phosphatidylinositol 3-kinase signaling and hence cancer development. Phosphatidylinositol 3-kinase regulatory subunit 1 underexpression was observed in 61.8% of breast cancer samples. Therefore, expression/alternations of phosphatidylinositol 3-kinase regulatory subunit 1 and phosphatase and tensin homolog genes have crucial roles for breast cancer progression. This review will summarize the biological roles of phosphatidylinositol 3-kinase regulatory subunit 1 and phosphatase and tensin homolog in breast cancer, with an emphasis on recent findings and the potential of phosphatidylinositol 3-kinase regulatory subunit 1 and phosphatase and tensin homolog as a therapeutic target for breast cancer therapy.

scholarly journals Molecular Analysis of AFP and HSA Interactions with PTEN Protein

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Mingyue Zhu ◽  
Bo Lin ◽  
Peng Zhou ◽  
Mengsen Li
Keyword(s):  
Molecular Docking ◽  
Molecular Mechanisms ◽  
Docking Study ◽  
Phosphatidylinositol 3 Kinase ◽  
Molecular Docking Study ◽  
Pten Protein ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Significant Homology ◽  
Modeling Data

Human cytoplasmic alpha-fetoprotein (AFP) has been classified as a member of the albuminoid gene family. The protein sequence of AFP has significant homology to that of human serum albumin (HSA), but its biological characteristics are vastly different from HSA. The AFP functions as a regulator in the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway, but HSA plays a key role as a transport protein. To probe their molecular mechanisms, we have applied colocalization, coimmunoprecipitation (co-IP), and molecular docking approaches to analyze the differences between AFP and HSA. The data from colocalization and co-IP displayed a strong interaction between AFP and PTEN (phosphatase and tensin homolog), demonstrating that AFP did bind to PTEN, but HSA did not. The molecular docking study further showed that the AFP domains I and III could contact with PTEN.In siliconsubstitutions of AFP binding site residues at position 490M/K and 105L/R corresponding to residues K490 and R105 in HSA resulted in steric clashes with PTEN residues R150 and K46, respectively. These steric clashes may explain the reason why HSA cannot bind to PTEN. Ultimately, the experimental results and the molecular modeling data from the interactions of AFP and HSA with PTEN will help us to identify targets for designing drugs and vaccines against human hepatocellular carcinoma.

scholarly journals Inversely proportional myelin growth due to altered Pmp22 gene dosage identifies PI3K/Akt/mTOR signaling as a novel therapeutic target in HNPP

2021 ◽  
Author(s):  
Doris Krauter ◽  
David Ewers ◽  
Timon J Hartmann ◽  
Stefan Volkmann ◽  
Theresa Kungl ◽  
...  
Keyword(s):  
Growth Regulation ◽  
Molecular Mechanisms ◽  
Motor Behavior ◽  
Gene Dosage ◽  
Mtor Signaling ◽  
Hereditary Neuropathy ◽  
Gene Encoding ◽  
Phosphatase And Tensin Homolog ◽  
Charcot Marie Tooth Disease ◽  
Tensin Homolog

Duplication of the gene encoding the myelin protein PMP22 causes the hereditary neuropathy Charcot-Marie-Tooth disease 1A (CMT1A), characterized by hypomyelination of medium to large peripheral axons. Conversely, haplo-insufficiency of PMP22 leads to focal myelin overgrowth in hereditary neuropathy with liability to pressure palsies (HNPP). However, the molecular mechanisms of myelin growth regulation by PMP22 remain obscure. Here, we found that the major inhibitor of the myelin growth signaling pathway PI3K/Akt/mTOR, phosphatase and tensin homolog (PTEN) is increased in abundance in CMT1A and decreased in HNPP rodent models. Indeed, treatment of DRG co-cultures from HNPP mice with PI3K/Akt/mTOR pathway inhibitors reduced focal hypermyelination and, importantly, treatment of HNPP mice with the mTOR inhibitor Rapamycin improved motor behavior, increased compound muscle amplitudes (CMAP) and reduced tomacula formation in the peripheral nerve. In Pmp22tg CMT1A mice, we uncovered that the differentiation defect of Schwann cells is independent from PI3K/Akt/mTOR activity, rendering the pathway insufficient as a therapy target on its own. Thus, while CMT1A pathogenesis is governed by dys-differentiation uncoupled from PI3K/Akt/mTOR signaling, targeting the pathway provides novel proof-of-principle for a therapeutic approach to HNPP.

scholarly journals PINK1/Parkin Mediated Mitophagy, Ca2+ Signalling, and ER–Mitochondria Contacts in Parkinson’s Disease

2020 ◽  
Vol 21 (5) ◽  
pp. 1772 ◽  
Author(s):  
Lucia Barazzuol ◽  
Flavia Giamogante ◽  
Marisa Brini ◽  
Tito Calì
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Endoplasmic Reticulum ◽  
Neurodegenerative Diseases ◽  
Current Knowledge ◽  
Phosphatase And Tensin Homolog ◽  
Cellular Processes ◽  
Selective Degradation ◽  
Contact Sites ◽  
Tensin Homolog

Endoplasmic reticulum (ER)–mitochondria contact sites are critical structures for cellular function. They are implicated in a plethora of cellular processes, including Ca2+ signalling and mitophagy, the selective degradation of damaged mitochondria. Phosphatase and tensin homolog (PTEN)-induced kinase (PINK) and Parkin proteins, whose mutations are associated with familial forms of Parkinson’s disease, are two of the best characterized mitophagy players. They accumulate at ER–mitochondria contact sites and modulate organelles crosstalk. Alterations in ER–mitochondria tethering are a common hallmark of many neurodegenerative diseases including Parkinson’s disease. Here, we summarize the current knowledge on the involvement of PINK1 and Parkin at the ER–mitochondria contact sites and their role in the modulation of Ca2+ signalling and mitophagy.

scholarly journals Pretreatment with phosphatase and tensin homolog deleted on chromosome 10 (PTEN) inhibitor SF1670 augments the efficacy of granulocyte transfusion in a clinically relevant mouse model

Blood ◽  
2011 ◽  
Vol 117 (24) ◽  
pp. 6702-6713 ◽  
Author(s):  
Yitang Li ◽  
Amit Prasad ◽  
Yonghui Jia ◽  
Saurabh Ghosh Roy ◽  
Fabien Loison ◽  
...  
Keyword(s):  
Therapeutic Strategy ◽  
Ex Vivo ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Granulocyte Transfusion ◽  
Chromosome 10 ◽  
Transfusion Therapy ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Bacteria Killing

Abstract The clinical outcome of granulocyte transfusion therapy is often hampered by short ex vivo shelf life, inefficiency of recruitment to sites of inflammation, and poor pathogen-killing capability of transplanted neutrophils. Here, using a recently developed mouse granulocyte transfusion model, we revealed that the efficacy of granulocyte transfusion can be significantly increased by elevating intracellular phosphatidylinositol (3,4,5)-trisphosphate signaling with a specific phosphatase and tensin homolog deleted on chromosome 10 (PTEN) inhibitor SF1670. Neutrophils treated with SF1670 were much sensitive to chemoattractant stimulation. Neutrophil functions, such as phagocytosis, oxidative burst, polarization, and chemotaxis, were augmented after SF1670 treatment. The recruitment of SF1670-pretreated transfused neutrophils to the inflamed peritoneal cavity and lungs was significantly elevated. In addition, transfusion with SF1670-treated neutrophils led to augmented bacteria-killing capability (decreased bacterial burden) in neutropenic recipient mice in both peritonitis and bacterial pneumonia. Consequently, this alleviated the severity of and decreased the mortality of neutropenia-related pneumonia. Together, these observations demonstrate that the innate immune responses can be enhanced and the severity of neutropenia-related infection can be alleviated by augmenting phosphatidylinositol (3,4,5)-trisphosphate in transfused neutrophils with PTEN inhibitor SF1670, providing a therapeutic strategy for improving the efficacy of granulocyte transfusion.

scholarly journals BMI1 promotes cardiac fibrosis in ischemia-induced heart failure via the PTEN-PI3K/Akt-mTOR signaling pathway

2019 ◽  
Vol 316 (1) ◽  
pp. H61-H69 ◽  
Author(s):  
Wenbo Yang ◽  
Zhijun Wu ◽  
Ke Yang ◽  
Yanxin Han ◽  
Yanjia Chen ◽  
...  
Keyword(s):  
Cardiac Fibrosis ◽  
Mammalian Target Of Rapamycin ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphatase And Tensin Homolog ◽  
B Lymphoma ◽  
Tensin Homolog ◽  
And Migration ◽  
Proliferation And Migration

Cardiac fibrosis has been known to play an important role in the etiology of heart failure after myocardial infarction (MI). B lymphoma Mo-MLV insertion region 1 homolog (BMI1), a transcriptional repressor, is important for fibrogenesis in the kidneys. However, the effect of BMI1 on ischemia-induced cardiac fibrosis remains unclear. BMI1 was strongly expressed in the infarct region 1 wk post-MI in mice and was detected by Western blot and histological analyses. Lentivirus-mediated overexpression of BMI1 significantly promoted cardiac fibrosis, worsened cardiac function 4 wk after the intervention in vivo, and enhanced the proliferation and migration capabilities of fibroblasts in vitro , whereas downregulation of BMI1 decreased cardiac fibrosis and prevented cardiac dysfunction in mice 4 wk post-MI in vivo. Furthermore, upregulated BMI1 inhibited phosphatase and tensin homolog (PTEN) expression, enhanced phosphatidylinositol 3-kinase (PI3K) expression, and increased the phosphorylation level of Akt and mammalian target of rapamycin (mTOR) in mice 4 wk after lentiviral infection, which was in accordance with the changes seen in their infarcted myocardial tissues. At the same time, the effects of BMI1 on cardiac fibroblasts were reversed in vitro when these cells were exposed to NVP-BEZ235, a dual-kinase (PI3K/mTOR) inhibitor. In conclusion, BMI1 is associated with cardiac fibrosis and dysfunction after MI by regulating cardiac fibroblast proliferation and migration, and these effects could be partially explained by the regulation of the PTEN-PI3K/Akt-mTOR pathway. NEW & NOTEWORTHY Ischemia-induced B lymphoma Mo-MLV insertion region 1 homolog (BMI1) significantly promoted cardiac fibrosis and worsened cardiac function in vivo, whereas downregulation of BMI1 decreased cardiac fibrosis and prevented cardiac dysfunction in myocardial infarcted mice. BMI1 also enhanced proliferation and migration capabilities of fibroblasts in vitro; these effects were reversed by NVP-BEZ235. Effects of BMI1 on cardiac fibrosis could be partially explained by regulation of the phosphatase and tensin homolog-phosphatidylinositol 3-kinase/Akt-mammalian target of rapamycin pathway.

scholarly journals The Role of PTEN in Tumor Angiogenesis

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Stéphane Rodriguez ◽  
Uyen Huynh-Do
Keyword(s):  
Tumor Angiogenesis ◽  
Molecular Mechanisms ◽  
Tumor Formation ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Physiological Processes ◽  
Response To Chemotherapy ◽  
Independent Functions ◽  
Pi3 Kinase Pathway

During the past 20 years, the phosphatase and tensin homolog PTEN has been shown to be involved in major physiological processes, and its mutation or loss is often associated with tumor formation. In addition PTEN regulates angiogenesis not only through its antagonizing effect on the PI3 kinase pathway mainly, but also through some phosphatase-independent functions. In this paper we delineate the role of this powerful tumor suppressor in tumor angiogenesis and dissect the underlying molecular mechanisms. Furthermore, it appears that, in a number of cancers, the PTEN status determines the response to chemotherapy, highlighting the need to monitor PTEN expression and to develop PTEN-targeted therapies.

scholarly journals Podocyte-specific knockin of PTEN protects kidney from hyperglycemia

2018 ◽  
Vol 314 (6) ◽  
pp. F1096-F1107 ◽  
Author(s):  
Huizhen Wang ◽  
Ziwei Feng ◽  
Jianteng Xie ◽  
Feng Wen ◽  
Menglei Jv ◽  
...  
Keyword(s):  
Diabetic Kidney Disease ◽  
Therapeutic Strategy ◽  
Renal Protection ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Matrix Expansion ◽  
Interfering Rna

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) has proven to be downregulated in podocytes challenged with high glucose (HG), and knockout of PTEN in podocytes aggravated the progression of diabetic kidney disease (DKD). However, whether podocyte-specific knockin of PTEN protects the kidney against hyperglycemia in vivo remains unknown. The inducible podocyte-specific PTEN knockin (PPKI) mice were generated by crossing newly created transgenic loxP-stop- loxP-PTEN mice with podocin-iCreERT2 mice. Diabetes mellitus was induced in mice by intraperitoneal injection of streptozotocin at a dose of 150 mg/kg. In vitro, small interfering RNA and adenovirus interference were used to observe the role of PTEN in HG-treated podocytes. Our data demonstrated that PTEN was markedly reduced in the podocytes of patients with DKD and focal segmental glomerulosclerosis, as well as in those of db/db mice. Interestingly, podocyte-specific knockin of PTEN significantly alleviated albuminuria, mesangial matrix expansion, effacement of podocyte foot processes, and incrassation of glomerular basement membrane in diabetic PPKI mice compared with wild-type diabetic mice, whereas no alteration was observed in the level of blood glucose. The potential renal protection of overexpressed PTEN in podocytes was partly attributed with an improvement in autophagy and motility and the inhibition of apoptosis. Our results showed that podocyte-specific knockin of PTEN protected the kidney against hyperglycemia in vivo , suggesting that targeting PTEN might be a novel and promising therapeutic strategy against DKD.

scholarly journals Peroxiredoxin III Protects Tumor Suppressor PTEN from Oxidation by 15-Hydroperoxy-eicosatetraenoic Acid

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Ying Zhang ◽  
Jiyoung Park ◽  
Seong-Jeong Han ◽  
Yongwoon Lim ◽  
Iha Park ◽  
...  
Keyword(s):  
Redox Regulation ◽  
Lipid Peroxide ◽  
Lipid Peroxides ◽  
Mouse Embryonic Fibroblast ◽  
Cysteine Residue ◽  
Eicosatetraenoic Acid ◽  
Phosphatase And Tensin Homolog ◽  
Active Site Cysteine ◽  
Cellular Processes ◽  
Tensin Homolog

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a lipid and protein phosphatase that coordinates various cellular processes. Its activity is regulated by the reversible oxidation of an active-site cysteine residue by H2O2 and thioredoxin. However, the potential role of lipid peroxides in the redox regulation of PTEN remains obscure. To evaluate this, 15-hydroperoxy-eicosatetraenoic acid (15s-HpETE), a lipid peroxide, was employed to investigate its effect on PTEN using molecular and cellular-based assays. Exposure to 15s-HpETE resulted in the oxidation of recombinant PTEN. Reversible oxidation of PTEN was also observed in mouse embryonic fibroblast (MEF) cells treated with a 15s-HpETE and Lipofectamine mixture. The oxidative dimerization of thioredoxin was found simultaneously. In addition, the absence of peroxiredoxin III aggravated 15s-HpETE-induced PTEN oxidation in MEF cells. Our study provides novel insight into the mechanism linking lipid peroxidation to the etiology of tumorigenesis.

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