Biology subjects

Ekiz, H. A.

Publications and source records attributed to Ekiz, H. A..

4 recordsLinked to original sources

bioRxiv2023

ARF6-dependent endocytic trafficking of the Interferon-γ receptor drives adaptive immune resistance in cancer.

Adaptive immune resistance (AIR) is a protective process used by cancer to escape elimination by CD8+ T cells. Inhibition of immune checkpoints PD-1 and CTLA-4 specifically target Interferon-gamma (IFN{gamma})-driven AIR. AIR begins at the plasma membrane where tumor cell-intrinsic cytokine signaling is initiated. Thus, plasma membrane remodeling by endomembrane trafficking could regulate AIR. Herein we report that the trafficking protein ADP-Ribosylation Factor 6 (ARF6) is critical for IFN{gamma}-driven AIR. ARF6 prevents transport of the receptor to the lysosome, augmenting IFN{gamma}R expression, tumor intrinsic IFN{gamma} signaling and downstream expression of immunosuppressive genes. In murine melanoma, loss of ARF6 causes resistance to immune checkpoint blockade (ICB). Likewise, low expression of ARF6 in patient tumors correlates with inferior outcomes with ICB. Our data provide new mechanistic insights into tumor immune escape, defined by ARF6-dependent AIR, and support that ARF6-dependent endomembrane trafficking of the IFN{gamma} receptor influences outcomes of ICB.

cancer biology↗

bioRxiv2023

TCGEx: A visual interface for multifaceted analyses of The Cancer Genome Atlas gene expression data

The Cancer Genome Atlas (TCGA) initiative has been essential for revealing key mechanisms in human cancer leading to the development of novel therapeutics. Analysis of the cancer transcriptomics data in the TCGA and other public repositories require coding skills that are associated with a steep learning curve for most non-specialists. To enable a wider utilization of these data, we introduce The Cancer Genome Explorer (TCGEx), a web-based visual data analysis interface that can perform a number of sophisticated analyses ranging from survival modeling and gene set enrichment analysis to unsupervised clustering and linear regression-based machine learning. In addition to providing access to preprocessed data from TCGA and immune checkpoint inhibition studies on cBioportal and CRI-iAtlas, the TCGEx platform allows users to upload and investigate their own data. Using this tool, we investigated the molecular subsets of human melanoma and identified microRNAs associated with intratumoral interferon signaling. We validated these findings using independent data from clinical trials involving immune check-point inhibitors for melanoma and other cancers. Moreover, our analyses unveiled a subset of cytokines predictive of positive responses to diverse immune checkpoint inhibitors prior to treatment initiation. Built on the R/Shiny framework, TCGEx modules offer customizable features to tailor the analysis to different study contexts and help generate publication-ready plots. TCGEx is freely available at https://tcgex.iyte.edu.tr, and it provides an interactive solution to extract meaningful insights from cancer transcriptomics data and guide scientific inquiry.

bioinformatics↗

bioRxiv2022

Senescence-Induced Immune Remodeling Facilitates Metastatic Adrenal Cancer in a Sex-Dimorphic Manner

Aging is a carcinogen that markedly increases cancer risk, yet we have limited mechanistic understanding of cancer initiation in aged cells. Here, we demonstrate induction of the hallmark aging process cellular senescence, triggered by loss of Wnt inhibitor ZNRF3, remodels the tissue microenvironment and ultimately permits metastatic adrenal cancer. Detailed characterization reveals a striking sexual dimorphism. Males exhibit earlier senescence activation and a greater innate immune response. This results in high myeloid cell accumulation and lower incidence of malignancy. Conversely, females present a dampened immune response and are more prone to metastatic cancer. Senescence-recruited myeloid cells become increasingly depleted with advanced tumor progression, which is recapitulated in patients where a low myeloid signature is associated with worse outcome. Collectively, our study reveals a novel role for myeloid cells in restraining adrenal cancer progression with significant prognostic value, and provides a model for interrogating pleiotropic effects of cellular senescence in cancer. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=67 SRC="FIGDIR/small/488426v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@bddf22org.highwire.dtl.DTLVardef@18434a3org.highwire.dtl.DTLVardef@9bc772org.highwire.dtl.DTLVardef@1430fbb_HPS_FORMAT_FIGEXP M_FIG Graphical abstract created with BioRender.com C_FIG

cancer biology↗

bioRxiv2020

Maternal schistosomiasis impairs offspring IL-4 production and B cell expansion

Maternal helminth infections are a global public health concern and correlate with altered infant immune responses to some childhood immunizations, but a mechanistic understanding of how maternal helminth infection alters the cellular immune responses of offspring is lacking. Here we establish a model of maternal Schistosoma mansoni infection in dual IL-4 reporter mice. We find that offspring born to mothers infected with S. mansoni have impaired production of IL-4 during homoeostasis, and following immunization with a Tetanus-Diphtheria vaccine. We identified that iNKT cells are the dominant source of IL-4 during early life homeostasis, and that diminished IL-4 production was associated with both reduced B cell and follicular dendritic cell responses. These defects were maintained long-term, affecting memory B and T cell responses. Single-cell RNASeq analysis of immunized offspring identified egg antigen-dependent reductions in B-cell cell cycle and proliferation-related genes. These data reveal that maternal infection leads to long-lasting defects in the cellular responses to heterologous antigens and provide vital insight into the influence of maternal infection on offspring immunity.

immunology↗