scholarly journals Acquired resistance of phosphatase and tensin homolog-deficient cells to poly(ADP-ribose) polymerase inhibitor and Ara-C mediated by 53BP1 loss and SAMHD1 overexpression

2018 ◽  
Vol 109 (3) ◽  
pp. 821-831 ◽  
Author(s):  
Yu-Ting Wang ◽  
Bo Yuan ◽  
Hua-Dong Chen ◽  
Lin Xu ◽  
Yu-Nan Tian ◽  
...  
Keyword(s):  
Acquired Resistance ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Polymerase Inhibitor

scholarly journals Mechanisms of stearoyl CoA desaturase inhibitor sensitivity and acquired resistance in cancer

2021 ◽  
Vol 7 (7) ◽  
pp. eabd7459
Author(s):  
Nicole Oatman ◽  
Nupur Dasgupta ◽  
Priyanka Arora ◽  
Kwangmin Choi ◽  
Mruniya V. Gawali ◽  
...  
Keyword(s):  
Cell Lines ◽  
Acquired Resistance ◽  
Normal Brain ◽  
Unexpected Finding ◽  
Epigenetic Alterations ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Stearoyl Coa Desaturase ◽  
Murine Osteosarcoma ◽  
Viral Oncogene Homolog

The lipogenic enzyme stearoyl CoA desaturase (SCD) plays a key role in tumor lipid metabolism and membrane architecture. SCD is often up-regulated and a therapeutic target in cancer. Here, we report the unexpected finding that median expression of SCD is low in glioblastoma relative to normal brain due to hypermethylation and unintentional monoallelic co-deletion with phosphatase and tensin homolog (PTEN) in a subset of patients. Cell lines from this subset expressed undetectable SCD, yet retained residual SCD enzymatic activity. Unexpectedly, these lines evolved to survive independent of SCD through unknown mechanisms. Cell lines that escaped such genetic and epigenetic alterations expressed higher levels of SCD and were highly dependent on SCD for survival. Last, we identify that SCD-dependent lines acquire resistance through a previously unknown FBJ murine osteosarcoma viral oncogene homolog B (FOSB)–mediated mechanism. Accordingly, FOSB inhibition blunted acquired resistance and extended survival of tumor-bearing mice treated with SCD inhibitor.

scholarly journals High Throughput Screen Identifies the DNMT1 (DNA Methyltransferase-1) Inhibitor, 5-Azacytidine, as a Potent Inducer of PTEN (Phosphatase and Tensin Homolog)

2020 ◽  
Vol 40 (8) ◽  
pp. 1854-1869
Author(s):  
Keith A. Strand ◽  
Sizhao Lu ◽  
Marie F. Mutryn ◽  
Linfeng Li ◽  
Qiong Zhou ◽  
...  
Keyword(s):  
Protein Expression ◽  
High Throughput ◽  
Knockout Mice ◽  
Vascular Remodeling ◽  
Dna Methyltransferase ◽  
Dna Methyltransferase 1 ◽  
Protective Effects ◽  
High Throughput Screen ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog

Objective: Our recent work demonstrates that PTEN (phosphatase and tensin homolog) is an important regulator of smooth muscle cell (SMC) phenotype. SMC-specific PTEN deletion promotes spontaneous vascular remodeling and PTEN loss correlates with increased atherosclerotic lesion severity in human coronary arteries. In mice, PTEN overexpression reduces plaque area and preserves SMC contractile protein expression in atherosclerosis and blunts Ang II (angiotensin II)-induced pathological vascular remodeling, suggesting that pharmacological PTEN upregulation could be a novel therapeutic approach to treat vascular disease. Approach and Results: To identify novel PTEN activators, we conducted a high-throughput screen using a fluorescence based PTEN promoter-reporter assay. After screening ≈3400 compounds, 11 hit compounds were chosen based on level of activity and mechanism of action. Following in vitro confirmation, we focused on 5-azacytidine, a DNMT1 (DNA methyltransferase-1) inhibitor, for further analysis. In addition to PTEN upregulation, 5-azacytidine treatment increased expression of genes associated with a differentiated SMC phenotype. 5-Azacytidine treatment also maintained contractile gene expression and reduced inflammatory cytokine expression after PDGF (platelet-derived growth factor) stimulation, suggesting 5-azacytidine blocks PDGF-induced SMC de-differentiation. However, these protective effects were lost in PTEN-deficient SMCs. These findings were confirmed in vivo using carotid ligation in SMC-specific PTEN knockout mice treated with 5-azacytidine. In wild type controls, 5-azacytidine reduced neointimal formation and inflammation while maintaining contractile protein expression. In contrast, 5-azacytidine was ineffective in PTEN knockout mice, indicating that the protective effects of 5-azacytidine are mediated through SMC PTEN upregulation. Conclusions: Our data indicates 5-azacytidine upregulates PTEN expression in SMCs, promoting maintenance of SMC differentiation and reducing pathological vascular remodeling in a PTEN-dependent manner.

miR-139-5p promotes neovascularization in diabetic retinopathy by regulating the phosphatase and tensin homolog

2021 ◽  
Vol 44 (2) ◽  
pp. 205-218
Author(s):  
Zhongwei Zhang ◽  
Caiping Song ◽  
Tao Wang ◽  
Lei Sun ◽  
Ling Qin ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog

scholarly journals The Mitochondrial Kinase PINK1 in Diabetic Kidney Disease

2021 ◽  
Vol 22 (4) ◽  
pp. 1525
Author(s):  
Chunling Huang ◽  
Ji Bian ◽  
Qinghua Cao ◽  
Xin-Ming Chen ◽  
Carol A. Pollock
Keyword(s):  
Kidney Disease ◽  
Diabetic Kidney Disease ◽  
Kidney Diseases ◽  
Mitochondrial Protein ◽  
Physiological Role ◽  
Close Link ◽  
Promising Alternative ◽  
Diabetic Kidney ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog

Mitochondria are critical organelles that play a key role in cellular metabolism, survival, and homeostasis. Mitochondrial dysfunction has been implicated in the pathogenesis of diabetic kidney disease. The function of mitochondria is critically regulated by several mitochondrial protein kinases, including the phosphatase and tensin homolog (PTEN)-induced kinase 1 (PINK1). The focus of PINK1 research has been centered on neuronal diseases. Recent studies have revealed a close link between PINK1 and many other diseases including kidney diseases. This review will provide a concise summary of PINK1 and its regulation of mitochondrial function in health and disease. The physiological role of PINK1 in the major cells involved in diabetic kidney disease including proximal tubular cells and podocytes will also be summarized. Collectively, these studies suggested that targeting PINK1 may offer a promising alternative for the treatment of diabetic kidney disease.

scholarly journals Hepatic HuR protects against the pathogenesis of non-alcoholic fatty liver disease by targeting PTEN

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Mi Tian ◽  
Jingjing Wang ◽  
Shangming Liu ◽  
Xinyun Li ◽  
Jingyuan Li ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Hepatic Steatosis ◽  
Chow Diet ◽  
Alcoholic Fatty Liver ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Pten Mrna ◽  
Normal Chow ◽  
Mice Liver

AbstractThe liver plays an important role in lipid and glucose metabolism. Here, we show the role of human antigen R (HuR), an RNA regulator protein, in hepatocyte steatosis and glucose metabolism. We investigated the level of HuR in the liver of mice fed a normal chow diet (NCD) and a high-fat diet (HFD). HuR was downregulated in the livers of HFD-fed mice. Liver-specific HuR knockout (HuRLKO) mice showed exacerbated HFD-induced hepatic steatosis along with enhanced glucose tolerance as compared with control mice. Mechanistically, HuR could bind to the adenylate uridylate-rich elements of phosphatase and tensin homolog deleted on the chromosome 10 (PTEN) mRNA 3′ untranslated region, resulting in the increased stability of Pten mRNA; genetic knockdown of HuR decreased the expression of PTEN. Finally, lentiviral overexpression of PTEN alleviated the development of hepatic steatosis in HuRLKO mice in vivo. Overall, HuR regulates lipid and glucose metabolism by targeting PTEN.

scholarly journals An Immunohistochemical Study of the PTEN/AKT Pathway Involvement in Canine and Feline Mammary Tumors

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 365
Author(s):  
Pietro Asproni ◽  
Francesca Millanta ◽  
Lorenzo Ressel ◽  
Fabio Podestà ◽  
Francesca Parisi ◽  
...  
Keyword(s):  
Immunohistochemical Study ◽  
Lymphatic Invasion ◽  
Pten Expression ◽  
Akt Pathway ◽  
Phosphatase And Tensin Homolog ◽  
Mammary Carcinomas ◽  
Tensin Homolog ◽  
Aggressive Tumors ◽  
Aggressive Subtype ◽  
Viral Oncogene Homolog

Phosphatase and tensin homolog deleted on chromosome10 (PTEN), phospho-v-Akt murine thymoma viral oncogene homolog (AKT), and the Rapamycin-Insensitive Companion of mTOR (Rictor) expression was investigated by immunohistochemistry in 10 canine mammary adenomas (CMAs), 40 canine mammary carcinomas (CMCs), and 30 feline mammary carcinomas (FMCs). All the CMAs, 25 of 40 CMCs (63%) and 7 of 30 FMCs (23%), were PTEN-positive. In dogs, no CMAs and 15 of 25 CMCs (37%) expressed phospho-AKT (p-AKT), while 24 of 30 FMCs (82%) were p-AKT-positive. One of 10 CMAs (10%), 24 of 40 CMCs (60%) and 20 of 30 FMCs (67%) were Rictor-positive. In the dog, PTEN expression correlated with less aggressive tumors, absence of lymphatic invasion, and longer survival. P-AKT expression correlated with more aggressive subtype, lymphatic invasion, and poorer survival and Rictor expression with lymphatic invasion. In cats, PTEN correlated with less aggressive carcinomas, absence of lymphatic invasion, and better survival. P-AKT and Rictor expression correlated with poorer survival. PTEN expression was inversely correlated with p-AKT and Rictor in both species, while p-AKT positively correlated with Rictor expression. A strong PTEN/AKT pathway involvement in behavior worsening of CMT and FMTs is demonstrated, providing a rationale for further studies of this pathway in veterinary oncology.

scholarly journals Esthetic and Functional Improvement of Asymmetric Lower Limb Overgrowth in a Proteus Syndrome Patient: a Combined Surgical Technique

2021 ◽  
Author(s):  
Francesca Riccardi ◽  
Simone Catapano ◽  
Giuseppe Cottone ◽  
Dino Zilio ◽  
Luca Vaienti
Keyword(s):  
Adipose Tissue ◽  
Lower Limb ◽  
Vascular Malformations ◽  
Functional Improvement ◽  
Proteus Syndrome ◽  
Phosphatase And Tensin Homolog ◽  
Tensin Homolog ◽  
Genetic Mosaicism ◽  
Phosphoinositide 3 Kinase ◽  
The Right

AbstractProteus syndrome is a rare, sporadic, congenital syndrome that causes asymmetric and disproportionate overgrowth of limbs, connective tissue nevi, epidermal nevi, alteration of adipose tissue, and vascular malformations. Genetic mosaicism, such as activating mutations involving protein kinase AKT1, phosphoinositide 3 kinase (PI3-K), and phosphatase and tensin homolog (PTEN), may be important causes of Proteus syndrome. However, many patients have no evidence of mutations in these genes. Currently, the diagnosis is clinical and based on phenotypic features. This article reports a case of Proteus syndrome in a 14-year-old female patient who presented with linear epidermal nevi, viscera anomalies, and adipose tissue dysregulation. She showed an asymmetric progressive overgrowth of the right lower limb after birth bringing relevant functional and esthetic consequences. Therefore, she asked a plastic surgery consultation and a surgical treatment with a combined technique was planned. With our approach, we were able to reduce leg diameter and improve joint mobility reliably and safely with satisfying esthetic results.

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