FK506 Attenuates the MRP1-Mediated Chemoresistant Phenotype in Glioblastoma Stem-Like Cells

Abstract

Poor response to current treatments for glioblastoma has been attributed to the presence of glioblastoma stem-like cells (GSCs). GSCs are able to expel antitumor drugs to the extracellular medium using the multidrug resistance-associated protein 1 (MRP1) transporter. Tacrolimus (FK506) has been identified as an MRP1 regulator in differentiated glioblastoma (GBM) cells (non-GSCs); however, the effect of FK506 on GSCs is currently unknown. The objective of the following research is to evaluate the effect of FK506 on the MRP1-related chemo-resistant phenotype of GSCs. For this, U87MG and C6 glioma cell lines were used to generate non-GSCs and GSCs. mRNA and MRP1-positive cells were evaluated by RT-qPCR and flow cytometry, respectively. A Carboxyfluorescein Diacetate (CFDA)-retention assay was performed to evaluate the MRP1 activity. Apoptosis and MTT assays were employed to evaluate the cytotoxic effects of FK506 plus Vincristine (MRP1 substrate). GSC-derived subcutaneous tumors were generated to evaluate the in vivo effect of FK506/Vincristine treatment. No differences in transcript levels and positive cells for MRP1 were observed in FK506-treated cells. Lesser cell viability, increased apoptosis, and CFDA-retention in the FK506/Vincristine-treated cells were observed. In vivo, the FK506/Vincristine treatment decreased the tumor size as well as ki67, Glial Fibrillary Acidic Protein (GFAP), and nestin expression. We conclude that FK506 confers a chemo-sensitive phenotype to MRP1-drug substrate in GSCs.

Adenosine Depletion as A New Strategy to Decrease Glioblastoma Stem-Like Cells Aggressiveness

“…Previously, our group confirmed that A 3 AR blockage decreased the expression of the ABC transporter MRP1, which is highly expressed in GBM, promoting chemoresistance to Vincristine [9,47]. Here we show that ADA is also able to decrease MRPs activity, conferring chemosensitivity to vincristine (Figure 5).…”

Identification of a Metabolism-Related Risk Signature Associated With Clinical Prognosis in Glioblastoma Using Integrated Bioinformatic Analysis

“…The antiangiogenic effect of rofecoxib makes GBM chemotherapy more effective (96). Tacrolimus endows the GBM stem-like cells chemosensitive to the MRP1 drug substrate (97). Of course, it is still controversial whether some of the drugs identified by our study are effective against GBM.…”

“…In this study, we used CMap analysis to accurately identify compounds that have been shown to have specific effects on GBM or other tumor types by comparing the different expression genes of GMB samples from 3 clusters. These compounds include the DNA synthesis inhibitor anisomycin ( 73 ), glutamate receptor antagonist amantadine ( 74 ), norepinephrine inhibitor amitriptyline ( 75 , 76 ), solute carrier family member inhibitor bumetanide ( 77 ), PPAR receptor agonist clofibrate ( 78 ), and fenofibrate ( 79 ), selective serotonin reuptake inhibitor (SSRI) fluoxetine ( 75 , 80 ), ATPase inhibitor helveticoside ( 81 , 82 ), norepinephrine reuptake inhibitor imipramine ( 75 , 76 , 83 , 84 ), opioid receptor agonist loperamide ( 85 ), phosphodiesterase inhibitor papaverine ( 86 , 87 ) and rolipram ( 88 – 92 ), polar auxin transport inhibitor quercetin ( 93 , 94 ), cyclooxygenase inhibitor rofecoxib ( 95 , 96 ), calcineurin inhibitor tacrolimus ( 97 ), purinergic receptor antagonist ticlopidine ( 98 , 99 ), HDAC inhibitor vorinostat ( 100 ), Rho associated kinase inhibitor Y-27632 ( 101 – 103 ).…”

Adenosinergic Pathway: A Hope in the Immunotherapy of Glioblastoma

“…In severe hypoxia, overexpression of hypoxia-inducible factor (HIF)-2α upregulates ectonucleotidases and adenosine production in the GME. Adenosine activates GSCs by stimulating A2bR and A3R, leading to disease progression, angiogenesis, and chemoresistance [ 124 , 125 ] ( Figure 1 ). Adenosine signaling via A3R on GSCs converts them to endothelial cells and increases tumor angiogenesis [ 56 , 103 ].…”