Anti-SLC7A11 (aa 215-229) polyclonal antibody

Recent studies have illustrated the growing importance of exosomes (small extracellular vesicles) and their constituent microRNAs (miRNAs) in the fields of toxicology and pathology. The mechanism of toxicity of toluene, a highly-prevalent and volatile organic compound, is largely unknown. To examine the role of miRNAs in toluene induced toxicity, we investigated miRNAs and toluene-induced gene expression in HL-60 human promyelocytic leukemia cells and exosomes using microarrays. A total of 54 miRNAs were differentially expressed in HL-60 cell lines exposed to toluene and exosomes from the cells. Four out of the 54 miRNAs (hsa-miR-1290, hsa-miR-718, hsa-miR-3663-3p, and hsa-miR-320c) were subsequently validated by qRT-PCR. Integrated analysis of miRNA and mRNA expression profiles identified 8 miRNA-mRNA correlations. By performing Comparative Toxicogenomics Database analysis, we found that the eight putative target genes of the differentially expressed miRNAs under toluene exposure (EXOSC6, RHOH, GFER, HERC2, GOLGA4, SLC7A11, GCLM, and BACH1) are related to diverse disease categories such as nervous system disease, cancer, cardiovascular disease, and respiratory tract disease. In conclusion, our data demonstrated that miRNA-mRNA networks provide a better understanding of toxicological mechanism caused by environmental pollutants in vitro using HL-60 cells and exosomes. (C) 2017 Elsevier Ltd. All rights reserved.

Cancer immunotherapy restores or enhances the effector function of CD8(+) T cells in the tumour microenvironment(1,2). CD8(+) T cells activated by cancer immunotherapy clear tumours mainly by inducing cell death through perforin-granzyme and Fas-Fas ligand pathways(3,4). Ferroptosis is a form of cell death that differs from apoptosis and results from iron-dependent accumulation of lipid peroxide(5,6). Although it has been investigated in vitro(7,8), there is emerging evidence that ferroptosis might be implicated in a variety of pathological scenarios(9,10). It is unclear whether, and how, ferroptosis is involved in T cell immunity and cancer immunotherapy. Here we show that immunotherapy-activated CD8(+) T cells enhance ferroptosis-specific lipid peroxidation in tumour cells, and that increased ferroptosis contributes to the antitumour efficacy of immunotherapy. Mechanistically, interferon gamma (IFN gamma) released from CD8(+) T cells downregulates the expression of SLC3A2 and SLC7A11, two subunits of the glutamate-cystine antiporter system x(c)(-), impairs the uptake of cystine by tumour cells, and as a consequence, promotes tumour cell lipid peroxidation and ferroptosis. In mouse models, depletion of cystine or cysteine by cyst(e)inase (an engineered enzyme that degrades both cystine and cysteine) in combination with checkpoint blockade synergistically enhanced T cell-mediated anti-tumour immunity and induced ferroptosis in tumour cells. Expression of system x(c)(- )was negatively associated, in cancer patients, with CD8(+) T cell signature, IFN gamma expression, and patient outcome. Analyses of human transcriptomes before and during nivolumab therapy revealed that clinical benefits correlate with reduced expression of SLC3A2 and increased IFN gamma and CD8. Thus, T cell-promoted tumour ferroptosis is an anti-tumour mechanism, and targeting this pathway in combination with checkpoint blockade is a potential therapeutic approach.