ABSTRACT
BACKGROUND: We investigated the unknown mechanisms of osimertinib-resistant EGFR-mutant lung cancer. METHODS: An osimertinib-resistant cell line (PC-9/OsmR2) was established through continuous exposure to osimertinib using an EGFR exon 19 deletion (19Del) lung adenocarcinoma cell line (PC-9). EGFR 19Del (M1), L858R/T790M/C797S (M6), and L858R/C797S (M8) expression vectors were introduced into Ba/F3 cells. A second osimertinib-resistant line (M1/OsmR) was established through continuous exposure to osimertinib using M1 cells. RESULTS: SLC1A3 had the highest mRNA expression level in PC-9/OsmR2 compared to PC-9 cells by microarray analysis and SLC1A3 was increased by flow cytometry. In PC-9/OsmR2 cells, osimertinib sensitivity was significantly increased in combination with siSLC1A3. Because SLC1A3 functions in glutamic acid transport, osimertinib with a glutaminase inhibitor (CB-839) or an SLC1A3 inhibitor (TFB-TBOA) increased the sensitivity. Also, CB-839 plus TFB-TBOA without osimertinib resulted in greater susceptibility than did CB-839 or TFB-TBOA plus osimertinib. Comprehensive metabolome analysis showed that the M1/OsmR cells had significantly more glutamine and glutamic acid than M1 cells. CB-839 plus osimertinib exerted a synergistic effect on M6 cells and an additive effect on M8 cells. CONCLUSION: Targeting glutaminase and glutamic acid may overcome the osimertinib-resistant EGFR-mutant lung cancer.
Subject(s)
Acrylamides , Aniline Compounds , Drug Resistance, Neoplasm , ErbB Receptors , Glutaminase , Lung Neoplasms , Mutation , Humans , Acrylamides/pharmacology , Aniline Compounds/pharmacology , Drug Resistance, Neoplasm/genetics , Drug Resistance, Neoplasm/drug effects , ErbB Receptors/genetics , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/metabolism , Lung Neoplasms/genetics , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Lung Neoplasms/metabolism , Cell Line, Tumor , Glutaminase/antagonists & inhibitors , Glutaminase/metabolism , Glutaminase/genetics , Excitatory Amino Acid Transporter 1/genetics , Excitatory Amino Acid Transporter 1/metabolism , Excitatory Amino Acid Transporter 1/antagonists & inhibitors , Benzeneacetamides/pharmacology , Adenocarcinoma of Lung/genetics , Adenocarcinoma of Lung/drug therapy , Adenocarcinoma of Lung/pathology , Adenocarcinoma of Lung/metabolism , Animals , Indoles , Pyrimidines , ThiadiazolesABSTRACT
Dysregulation of epigenetics is a hallmark of cancer development, and YTHDF1 stands out as a crucial epigenetic regulator with the highest DNA copy number variation among all N6-methyladenosine (m6A) regulators in colorectal cancer (CRC) patients. Here, we aimed to investigate the specific contribution of YTHDF1 overexpression to CRC progression and its consequences. Through multiple bioinformatic analysis of human cancer databases and clinical CRC samples, we identified GID8/Twa1 as a crucial downstream target of YTHDF1. YTHDF1 manipulates GID8 translation efficiency in a m6A-dependent manner, and high expression of GID8 is associated with more aggressive tumor progression and poor overall survival. Mechanistically, GID8 is intimately associated with glutamine metabolic demands by maintaining active glutamine uptake and metabolism through the regulation of excitatory amino acid transporter 1 (SLC1A3) and glutaminase (GLS), thereby facilitating the malignant progression of CRC. Inhibition of GID8 attenuated CRC proliferation and metastasis both in vitro and in vivo. In summary, we identified a previously unknown target pertaining to glutamine uptake and metabolism in tumor cells, underscoring the potential of GID8 in the treatment of CRC.
ABSTRACT
Dysfunction in ion channels or processes involved in maintaining ionic homeostasis is thought to lower the threshold for cortical spreading depression (CSD), and plays a role in susceptibility to associated neurological disorders, including pathogenesis of a migraine. Rare pathogenic variants in specific ion channels have been implicated in monogenic migraine subtypes. In this study, we further examined the channelopathic nature of a migraine through the analysis of common genetic variants in three selected ion channel or transporter genes: SLC4A4, SLC1A3, and CHRNA4. Using the Agena MassARRAY platform, 28 single-nucleotide polymorphisms (SNPs) across the three candidate genes were genotyped in a case-control cohort comprised of 182 migraine cases and 179 matched controls. Initial results identified significant associations between migraine and rs3776578 (p = 0.04) and rs16903247 (p = 0.05) genotypes within the SLC1A3 gene, which encodes the EAAT1 glutamate transporter. These SNPs were subsequently genotyped in an independent cohort of 258 migraine cases and 290 controls using a high-resolution melt assay, and association testing supported the replication of initial findings-rs3776578 (p = 0.0041) and rs16903247 (p = 0.0127). The polymorphisms are in linkage disequilibrium and localise within a putative intronic enhancer region of SLC1A3. The minor alleles of both SNPs show a protective effect on migraine risk, which may be conferred via influencing the expression of SLC1A3.