Search results for "Pten"
showing 10 items of 211 documents
PTEN negatively regulates the cell lineage progression from NG2+ glial progenitor to oligodendrocyte via mTOR-independent signaling
2018
Oligodendrocytes (OLs), the myelin-forming CNS glia, are highly vulnerable to cellular stresses, and a severe myelin loss underlies numerous CNS disorders. Expedited OL regeneration may prevent further axonal damage and facilitate functional CNS repair. Although adult OL progenitors (OPCs) are the primary players for OL regeneration, targetable OPC-specific intracellular signaling mechanisms for facilitated OL regeneration remain elusive. Here, we report that OPC-targeted PTEN inactivation in the mouse, in contrast to OL-specific manipulations, markedly promotes OL differentiation and regeneration in the mature CNS. Unexpectedly, an additional deletion of mTOR did not reverse the enhanced O…
PTEN recruitment controls synaptic and cognitive function in Alzheimer's models
2016
Dyshomeostasis of amyloid-β peptide (Aβ) is responsible for synaptic malfunctions leading to cognitive deficits ranging from mild impairment to full-blown dementia in Alzheimer's disease. Aβ appears to skew synaptic plasticity events toward depression. We found that inhibition of PTEN, a lipid phosphatase that is essential to long-term depression, rescued normal synaptic function and cognition in cellular and animal models of Alzheimer's disease. Conversely, transgenic mice that overexpressed PTEN displayed synaptic depression that mimicked and occluded Aβ-induced depression. Mechanistically, Aβ triggers a PDZ-dependent recruitment of PTEN into the postsynaptic compartment. Using a PTEN kno…
Transcription factor NRF2 as a therapeutic target for chronic diseases: a systems medicine approach
2018
Systems medicine has a mechanism-based rather than a symptom- or organ-based approach to disease and identifies therapeutic targets in a nonhypothesis-driven manner. In this work, we apply this to transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF2) by cross-validating its position in a protein-protein interaction network (the NRF2 interactome) functionally linked to cytoprotection in low-grade stress, chronic inflammation, metabolic alterations, and reactive oxygen species formation. Multiscale network analysis of these molecular profiles suggests alterations of NRF2 expression and activity as a common mechanism in a subnetwork of diseases (the NRF2 diseasome). This netw…
Cytoplasmic localization of the cell polarity factor scribble supports liver tumor formation and tumor cell invasiveness
2018
The loss of epithelial cell polarity plays an important role in the development and progression of liver cancer. However, the specific molecular mechanisms supporting tumor initiation and progression are poorly understood. In this study, transcriptome data and immunofluorescence stains of tissue samples derived from hepatocellular carcinoma (HCC) patients revealed that overexpression associated with cytoplasmic localization of the baso-lateral cell polarity complex protein Scribble (Scrib) correlated with poor prognosis of HCC patients. In comparison to HCC cells stably expressing wildtype Scrib (ScribWT), mutated Scrib with enforced cytoplasmic enrichment (ScribP305L) induced AKT signaling…
Finding the right biomarker for renal cell carcinoma (RCC): Nivolumab treatment induces the expression of specific peripheral lymphocyte microRNAs in…
2019
Abstract Background The variability of clinical response to immune checkpoint inhibitors in RCC patients makes necessary the discovery of predictive biomarkers for patient selection. Emerging evidence has revealed a multitude of silenced genes and deregulated signalling pathways. These findings point towards extensive microRNAs (miRNAs) regulation and imply epigenetic reprogramming as a key feature of RCC. The aim of this study was to analyze the peripheral lymphocyte miRNA expression profile in metastatic RCC patients undergoing nivolumab treatment, to identify a lymphocyte miRNA signature specifically expressed in patients with partial or complete response (RP; RC) >12 months. Methods miR…
The role of extracellular calcium in bone metastasis
2016
AbstractThis review summarizes the role of extracellular calcium, as found present in the bone tissue, in the process of bone metastasis.
Exosomes as delivery vehicles: a commentary on "Amoxicillin haptenates intracellular proteins that can be transported in exosomes to target cells".
2017
Exosomes are lipoproteic nanosize vesicles of endocytic origin that are released in the extracellular space by several cell types when a multivesicular body fuses with the plasma membrane (1). To date, accumulating evidences highlight the potential of exosomes as messenger in intercellular communication. Indeed, several studies reported the presence of lipids, proteins, metabolites and nucleic acid (DNA, mRNA, microRNA, lncRNA) in exosomes and highlight their functional role in physiological and pathological processes (2).
Concordance of Genomic Alterations between Primary and Recurrent Breast Cancer
2014
Abstract There is growing interest in delivering genomically informed cancer therapy. Our aim was to determine the concordance of genomic alterations between primary and recurrent breast cancer. Targeted next-generation sequencing was performed on formalin-fixed paraffin-embedded (FFPE) samples, profiling 3,320 exons of 182 cancer-related genes plus 37 introns from 14 genes often rearranged in cancer. Point mutations, indels, copy-number alterations (CNA), and select rearrangements were assessed in 74 tumors from 43 patients (36 primary and 38 recurrence/metastases). Alterations potentially targetable with established or investigational therapeutics were considered “actionable.” Alterations…
PI3K pathway mutations and PTEN levels in primary and metastatic breast cancer.
2011
Abstract The purpose of this work was to determine whether there are differences in PIK3CA mutation status and PTEN protein expression between primary and matched metastatic breast tumors as this could influence patient management. Paraffin sections of 50 μm were used for DNA extraction and slides of 3 μm for immunohistochemistry (IHC) and FISH. Estrogen receptor, progesterone receptor, and HER2 IHC were repeated in a central laboratory for both primary tumors and metastases. PTEN levels were assessed by IHC and phosphoinositide 3-kinase (PI3K) pathway mutations were detected by a mass spectroscopy–based approach. Median age was 48 years (range: 30–83 years). Tumor subtype included 72% horm…
A First-in-Human Phase I Study of the ATP-Competitive AKT Inhibitor Ipatasertib Demonstrates Robust and Safe Targeting of AKT in Patients with Solid …
2016
Abstract Activation of AKT signaling by PTEN loss or PIK3CA mutations occurs frequently in human cancers, but targeting AKT has been difficult due to the mechanism-based toxicities of inhibitors that target the inactive conformation of AKT. Ipatasertib (GDC-0068) is a novel selective ATP-competitive small-molecule inhibitor of AKT that preferentially targets active phosphorylated AKT (pAKT) and is potent in cell lines with evidence of AKT activation. In this phase I study, ipatasertib was well tolerated; most adverse events were gastrointestinal and grade 1–2 in severity. The exposures of ipatasertib ≥200 mg daily in patients correlated with preclinical TGI90, and pharmacodynamic studies co…