Dataset Information

Inhibition of nuclear PTEN tyrosine phosphorylation enhances glioma radiation sensitivity through attenuated DNA repair

ABSTRACT: Glioblastoma (GBM) is the most lethal brain tumour that occurs in adults and treatment for GBM has been largely unsuccessful. Ionizing radiation (IR) and chemotherapeutic agents are employed as standard of care treatment for GBM patients and both result in DNA damage. Previous data identified phosphorylation of PTEN at tyrosine 240 (pY240) in samples from patients with recurrent GBM receiving standard of care treatment and was associated with decreased overall survival. Here we demonstrate that pY240 PTEN that was triggered by FGFR2 signaling, enhanced DNA repair by facilitating the loading of PTEN onto chromatin through its interaction with KI-67 and subsequent recruitment of the DNA repair protein, RAD51, to sites of DNA damage. Thus, tumour cells with pY240 PTEN are efficient at repairing DNA damage which would be predicted to result in resistance to therapy. These findings suggest the FGFR-pY240 PTEN-DNA repair mechanism as a therapeutic target for enhancing GBM therapy.

INSTRUMENT(S): LTQ Orbitrap

ORGANISM(S): Homo Sapiens (ncbitaxon:9606)

SUBMITTER: Frank B. Furnari1

PROVIDER: MSV000081423 | MassIVE | Mon Aug 07 14:57:00 BST 2017

SECONDARY ACCESSION(S): PXD007212

REPOSITORIES: MassIVE

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Publications

Inhibition of Nuclear PTEN Tyrosine Phosphorylation Enhances Glioma Radiation Sensitivity through Attenuated DNA Repair.

Ma Jianhui J Benitez Jorge A JA Li Jie J Miki Shunichiro S Ponte de Albuquerque Claudio C Galatro Thais T Orellana Laura L Zanca Ciro C Reed Rachel R Boyer Antonia A Koga Tomoyuki T Varki Nissi M NM Fenton Tim R TR Nagahashi Marie Suely Kazue SK Lindahl Erik E Gahman Timothy C TC Shiau Andrew K AK Zhou Huilin H DeGroot John J Sulman Erik P EP Cavenee Webster K WK Kolodner Richard D RD Chen Clark C CC Furnari Frank B FB

Cancer cell 20190228 3

Ionizing radiation (IR) and chemotherapy are standard-of-care treatments for glioblastoma (GBM) patients and both result in DNA damage, however, the clinical efficacy is limited due to therapeutic resistance. We identified a mechanism of such resistance mediated by phosphorylation of PTEN on tyrosine 240 (pY240-PTEN) by FGFR2. pY240-PTEN is rapidly elevated and bound to chromatin through interaction with Ki-67 in response to IR treatment and facilitates the recruitment of RAD51 to promote DNA re ...[more]

PMID: 30827889

Similar Datasets

Project description:PD-L1 Inhibitor Regulates the miR-33a-5p/PTEN Signaling Pathway and Can Be Targeted to Sensitize Glioblastomas to Radiation. Glioblastoma (GBM) is the most common and lethal brain tumor in adults. Ionizing radiation (IR) is a standard treatment for GBM patients and results in DNA damage. However, the clinical efficacy of IR is limited due to therapeutic resistance. The programmed death ligand 1 (PD-L1) blockade has a shown the potential to increase the efficacy of radiotherapy by inhibiting DNA damage and repair responses. The miR-33a-5p is an essential microRNA that promotes GBM growth and self-renewal. In this study, we investigated whether a PD-L1 inhibitor (a small molecule inhibitor) exerted radio-sensitive effects to impart an anti-tumor function in GBM cells by modulating miR-33a-5p. U87 MG cells and U251 cells were pretreated with PD-L1 inhibitor. The PD-L1 inhibitor-induced radio-sensitivity in these cells was assessed by assaying cellular apoptosis, clonogenic survival assays, and migration. TargetScan and luciferase assay showed that miR-33a-5p targeted the phosphatase and tensin homolog (PTEN) 3' untranslated region. The expression level of PTEN was measured by western blotting, and was also silenced using small interfering RNAs. The levels of DNA damage following radiation was measured by the presence of γ-H2AX foci, cell cycle, and the mRNA of the DNA damage-related genes, BRCA1, NBS1, RAD50, and MRE11. Our results demonstrated that the PD-L1 inhibitor significantly decreased the expression of the target gene, miR-33a-5p. In addition, pretreatment of U87 MG and U251 cells with the PD-L1 inhibitor increased radio-sensitivity, as indicated by increased apoptosis, while decreased survival and migration of GBM cells. Mir-33a-5p overexpression or silencing PTEN in U87 MG and U251 cells significantly attenuated PD-L1 radiosensitive effect. Additionally, PD-L1 inhibitor treatment suppressed the expression of the DNA damage response-related genes, BRCA1, NBS1, RAD50, and MRE11. Our results demonstrated a novel role for the PD-L1 inhibitor in inducing radio- sensitivity in GBM cells, where inhibiting miR-33a-5p, leading to PTEN activated, and inducing DNA damage was crucial for antitumor immunotherapies to treat GBM.