1. FK506 Attenuates the MRP1-Mediated Chemoresistant Phenotype in Glioblastoma Stem-Like Cells.
- Author
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Torres Á, Arriagada V, Erices JI, Toro MLÁ, Rocha JD, Niechi I, Carrasco C, Oyarzún C, and Quezada C
- Subjects
- Animals, Antineoplastic Agents, Phytogenic pharmacology, Apoptosis drug effects, Brain Neoplasms genetics, Brain Neoplasms metabolism, Brain Neoplasms pathology, Cell Line, Tumor, Glioblastoma genetics, Glioblastoma metabolism, Glioblastoma pathology, Humans, Male, Multidrug Resistance-Associated Proteins metabolism, Neoplastic Stem Cells metabolism, Neoplastic Stem Cells pathology, Phenotype, Rats, Sprague-Dawley, Tacrolimus pharmacology, Vincristine pharmacology, Antineoplastic Agents, Phytogenic therapeutic use, Brain Neoplasms drug therapy, Drug Resistance, Neoplasm drug effects, Glioblastoma drug therapy, Multidrug Resistance-Associated Proteins genetics, Neoplastic Stem Cells drug effects, Tacrolimus therapeutic use, Vincristine therapeutic use
- 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.
- Published
- 2018
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