Biology subjects

Zannikou, M.

Publications and source records attributed to Zannikou, M..

5 recordsLinked to original sources

bioRxiv2023

S100A8/A9 predicts triple-negative breast cancer response to PIM kinase and PD-1/PD-L1 inhibition

It remains elusive why some triple-negative breast cancer (TNBC) patients respond poorly to existing therapies while others respond well. Our retrospective analysis of historical gene expression datasets reveals that increased expression of immunosuppressive cytokine S100A8/A9 in early-stage tumors is robustly associated with subsequent disease progression in TNBC. Although it has recently gained recognition as a potential anticancer target, S100A8/A9 has not been integrated into clinical study designs evaluating molecularly targeted therapies. Our small molecule screen has identified PIM kinase inhibitors as capable of decreasing S100A8/A9 expression in multiple cell types, including TNBC and immunosuppressive myeloid cells. Furthermore, combining PIM inhibition and immune checkpoint blockade induces significant antitumor responses, especially in otherwise resistant S100A8/A9-high PD-1/PD-L1-positive tumors. Importantly, serum S100A8/A9 levels mirror those of tumor S100A8/A9 in a syngeneic mouse model of TNBC. Thus, our data suggest that S100A8/A9 could be a predictive and pharmacodynamic biomarker in clinical trials evaluating combination therapy targeting PIM and immune checkpoints in TNBC and encourage the development of S100A8/A9-based liquid biopsy tests.

cancer biology↗

bioRxiv2022

Low Level Whole-Brain Radiation Enhances Theranostic Potential Of Single Domain Antibody Fragments For HER2-Positive Brain Metastases

BackgroundSingle-domain antibody fragments (aka VHH, [~]13 kDa) are promising delivery systems for brain tumor theranostics; however, achieving efficient delivery of VHH to intracranial lesions remains challenging due to the tumor-brain barrier. Here, we evaluate low-dose whole-brain irradiation as a strategy to increase the delivery of an anti-HER2 VHH to breast cancer-derived intracranial tumors in mice. MethodsMice with intracranial HER2-positive BT474BrM3 tumors received 10-Gy fractionated cranial irradiation and evaluated using non-invasive imaging methods. The anti-HER2 VHH 5F7 was labeled with 18F, administered intravenously to irradiated mice and controls, and PET/CT imaging was conducted at various intervals after irradiation. Tumor uptake of 18F-labeled 5F7 in irradiated and control mice was compared by PET/CT image analysis and correlated with tumor volumes. In addition, longitudinal dynamic contrast-enhanced MRI (DCE-MRI) was conducted to visualize and quantify the potential effects of radiation on tumor perfusion and permeability. ResultsIncreased 18F-labeled 5F7 intracranial tumor uptake was observed with PET in mice that received cranial irradiation, with maximum tumor accumulation seen approximately 12 days post initial radiation treatment. No radiation-induced changes in HER2 expression were detected by Western blot, flow cytometry, or on tissue sections. DCE-MRI imaging demonstrated transiently increased tumor perfusion and permeability after irradiation, consistent with the higher tumor uptake of 18F-labeled anti-HER2 5F7 in irradiated mice. ConclusionLow-level brain irradiation induces dynamic changes in tumor vasculature that increase the intracranial tumor delivery of an anti-HER2 VHH, which could facilitate the use of labeled sdAb to detect, monitor, and treat HER2-expressing brain metastases. Key pointsO_LILow-level radiation enhances uptake of HER2-specific VHH in intracranial tumors. C_LIO_LIXRT + radiolabeled VHH shows promise as a treatment strategy for breast cancer brain metastases. C_LI Importance of the StudyImproving the detection and treatment of brain metastases (BM) that overexpress human epidermal growth factor receptor type 2 (HER2) is an urgent medical need. Drug delivery to BM is confounded by their tumor vasculature, which is more restrictive than in GBM. Single domain antibody fragments, about one-tenth the size of antibodies, could be promising theranostic vectors for BM provided sufficient BM uptake could be achieved. In this study, we utilized longitudinal PET imaging to demonstrate that low-dose whole-brain irradiation (WBRT) significantly increased 18F-labeled HER2-specific 5F7 VHH uptake in intracranial HER2-positive tumors in mice. Combining low dose WBRT with 5F7 VHH labeled with -or {beta}-particle emitting radionuclides could provide an effective and specific targeted radiotherapeutic strategy for treating patients with HER2-expressing BM.

cancer biology↗

bioRxiv2021

A New Mouse Model of Diffuse Midline Glioma to Test Targeted Immunotherapies

BACKGROUNDDiffuse midline gliomas remain incurable, with consistently poor outcomes in children despite radiotherapy. Immunotherapeutic approaches hold promise, with the integration of the hosts immune system fundamental to their design. Here, we describe a new, genetically engineered immunocompetent model that incorporates interleukin 13 receptor alpha 2 (IL13R2), a tumor-associated antigen, which is suitable for further evaluation of the antitumor activity of IL13R2-targeted immunotherapeutics in preclinical studies. METHODSThe RCAS-Tv-a delivery system was used to induce gliomagenesis through overexpression of PDGFB and p53 deletion with and without human IL13R2 in Nestin-Tva; p53fl/fl mice. Hindbrain or cerebral cortex nestin progenitors of neonatal pups were infected with Cre recombinase and PDGFB+IL13R2 or Cre recombinase and PDGFB to model diffuse midline glioma and supratentorial high-grade glioma, respectively. Immunoblotting and flow cytometry was used to confirm target expression. Kaplan-Meier survival curves were established to compare tumor latency in both models. Tumor tissue was analyzed through immunohistochemistry and H&E staining. Cell lines generated from tumor-bearing mice were used for in vitro studies and orthotopic injections. RESULTSThe protein expression of PDGFB and IL13R2 was confirmed by flow cytometry and western blot. In both groups, de novo tumors developed without significant difference in median survival between PDGFB and p53 loss (n=25, 40 days) and PDGFB, IL13R2, and p53 loss (n=33, 38 days, p=0.62). Tumors demonstrated characteristics of high-grade glioma such as infiltration, palisading necrosis, microvascular proliferation, high Ki-67 index, heterogeneous IL13R2 expression, and CD11b+ macrophages, along with a low proportion of CD3+ T cells. Orthotopic tumors developed from cell lines retained histopathological characteristics of de novo tumors. Mice orthotopically implanted with cells in the hindbrain or right cortex showed a median survival of 42 days and 41 (p=0.56) days, respectively. CONCLUSIONGeneration of de novo tumors using the RCAS-Tv-a delivery system was successful, with tumors possessing histopathologic features common to pediatric diffuse gliomas. The development of these models opens the opportunity for preclinical assessment of IL13R2-directed immunotherapies with the potential for clinical translation.

cancer biology↗

bioRxiv2020

Neural Stem Cells Secreting Bispecific T Cell Engager to Induce Selective Anti-Glioma Activity

Glioblastoma (GBM) is the most lethal primary brain tumor in adults. There is no treatment that provides durable relief for the vast majority of GBM patients. In this study, weve tested a bispecific antibody comprised of single-chain variable regions (scFvs) against T cell CD3{varepsilon} and GBM cell interleukin 13 receptor alpha 2 (IL13R2). We demonstrate that this BiTE (BiTELLON) engages peripheral and tumor-infiltrating lymphocytes harvested from patients tumors, and in so doing exerts anti-GBM activity ex vivo. The interaction of BiTELLON with T cells and engagement of IL13R2-expressing GBM cells stimulates T cell proliferation as well as production of pro-inflammatory cytokines INF{gamma} and TNF. We have modified neural stem cells (NSCs) to produce and secrete the BiTE (NSCsLLON). When injected intracranially in mice with brain tumor, NSCsLLON show tropism for tumor, secrete BiTELLON, and remain viable for several days. When injected directly into tumor, NSCLLON provide significant survival benefit to mice bearing IL13R2+ GBM. Our results support further investigation and development of this therapeutic for clinical translation.

immunology↗

bioRxiv2019

Interaction between DNA damage response, translation and apoptosome determines cancer susceptibility to TOP2 poisons

Topoisomerase II poisons are one of the most common class of chemotherapeutics used in cancer. We show that glioblastoma (GBM), the most malignant of all primary brain tumors in adults is responsive to TOP2 poisons. To identify genes that confer susceptibility to this drug in gliomas, we performed a genome-scale CRISPR knockout screen with etoposide. Genes involved in protein synthesis and DNA damage were implicated in etoposide susceptibility. To define potential biomarkers for TOP2 poisons, CRISPR hits were overlapped with genes whose expression correlates with susceptibility to this drug across glioma cell lines, revealing ribosomal protein subunit RPS11, 16, 18 as putative biomarkers for response to TOP2 poisons. Loss of RPS11 impaired the induction of pro-apoptotic gene APAF1 following etoposide treatment, and led to resistance to this drug and doxorubicin. The expression of these ribosomal subunits was also associated with susceptibility to TOP2 poisons across cell lines from multiple cancers.\n\nGraphical Abstract\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=93 SRC=\"FIGDIR/small/614024v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (14K):\norg.highwire.dtl.DTLVardef@310f7org.highwire.dtl.DTLVardef@14ed578org.highwire.dtl.DTLVardef@a0d9c0org.highwire.dtl.DTLVardef@37f59a_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗