Product Citations: 50

Epstein-Barr virus-associated gastric carcinoma (EBVaGC) is a subset of gastric cancers linked to EBV infection. While the role of male hormones in cancers such as prostate, breast, and ovarian cancers is well-studied, their impact on EBVaGC remains less understood. This study aims to examine the effect of dihydrotestosterone (DHT) on EBVaGC, particularly focusing on its influence on the immune response.
The study utilized the SNU719 EBVaGC cell line. Cells were treated with DHT to assess androgen receptor (AR) expression and the activation of signaling pathways, including NF-κB. The expression of MHC class I polypeptide-related sequence A (MICA) and its interaction with the NKG2D receptor on NK and T cells was evaluated. Cytotoxicity assays were conducted to determine DHT's effect on NK and T cell-mediated cytotoxicity, and proinflammatory cytokine gene expression was analyzed.
DHT significantly increased AR expression in EBVaGC cells and activated the NF-κB pathway, which led to increased transcription of target genes such as MICA and EBNA1. These changes enhanced the interaction with receptors on NK and T cells, thereby boosting their cytotoxicity against EBVaGC cells. Importantly, DHT did not upregulate proinflammatory cytokine genes.
DHT enhances the immune response against EBVaGC by upregulating MICA and activating NK and T cells. These findings suggest potential therapeutic strategies targeting androgen signaling to improve anti-tumor immunity in EBVaGC.

  • FC/FACS
  • Homo sapiens (Human)
  • Cancer Research
  • Immunology and Microbiology

Development of an Orthotopic HPV16-Dependent Base of Tongue Tumor Model in MHC-Humanized Mice.

In Pathogens on 25 January 2023 by Schifflers, C., Zottnick, S., et al.

Head and neck squamous cell carcinomas (HNSCC) caused by infections with high-risk human papillomaviruses (HPV) are responsible for an increasing number of head and neck cancers, particularly in the oropharynx. Despite the significant biological differences between HPV-driven and HPV-negative HNSCC, treatment strategies are similar and not HPV targeted. HPV-driven HNSCC are known to be more sensitive to treatment, particularly to radiotherapy, which is at least partially due to HPV-induced immunogenicity. The development of novel therapeutic strategies that are specific for HPV-driven cancers requires tumor models that reflect as closely as possible the characteristics and complexity of human tumors and their response to treatment. Current HPV-positive cancer models lack one or more hallmarks of their human counterpart. This study presents the development of a new HPV16 oncoprotein-dependent tumor model in MHC-humanized mice, modeling the major biologic features of HPV-driven tumors and presenting HLA-A2-restricted HPV16 epitopes. Furthermore, this model was developed to be orthotopic (base of tongue). Thus, it also reflects the correct tumor microenvironment of HPV-driven HNSCC. The cancer cells are implanted in a manner that allows the exact control of the anatomical location of the developing tumor, thereby homogenizing tumor growth. In conclusion, the new model is suited to study HPV16-specific therapeutic vaccinations and other immunotherapies, as well as tumor-targeted interventions, such as surgery or radiotherapy, or a combination of all these modalities.

  • FC/FACS
  • Cancer Research
  • Immunology and Microbiology

Background: Adoptive T cell therapies including T cell receptor-engineered T (TCR-T) cell therapy are limited by poor in-vivo persistence. According to literature, aurora kinase inhibitors elicit glycolysis suppression and fatty acid oxidation enhancement. Less differentiated memory T cells rely more on fatty acid oxidation with better proliferative potency. Therefore, this study aims to determine whether aurora kinase inhibition during TCR-T cell preparation and expansion promote a more long-lived phenotype leading to T cells with increased in vivo persistence and efficacy. Methods The study involves preparing TCR-T cells with aurora kinase inhibitors for 7 days with anti-CD3/CD28 beads and IL-2. And the antitumor effects of these TCR-T cells were investigated in vitro and in subcutaneous and metastatic melanoma models. Results TCR-T cells cultured with aurora kinase A and B inhibitor generated more effector T cells (~ 79% and ~ 77%) when compared to cells with beads alone (~ 36%) after in-vitro re-stimulation. And aurora kinase B inhibitor-treatment benefits in vivo persistence of TCR-T cells and extends survival in both subcutaneous and metastatic melanoma model. Phenotypic analysis shows an increased percentage of T cells stem cell-like memory properties in terms of aurora kinase inhibition. The stemness of T cells is maintained by delaying proliferation mediated by limitation of mTOR activity. Conclusion Taken together, these data suggest that incorporation of aurora kinase inhibitor in TCR-T cells preparation might be a potential method to generate long-live TCR-T cells with potent therapeutic characteristics.

  • Immunology and Microbiology
  • Stem Cells and Developmental Biology

SERPINB9 is commonly amplified and high expression in cancer cells correlates with poor immune checkpoint blockade response.

In Oncoimmunology on 6 December 2022 by Ibáñez-Molero, S., van Vliet, A., et al.

Immunotherapies, in particular immune checkpoint blockade (ICB), have improved the clinical outcome of cancer patients, although many fail to mount a durable response. Several resistance mechanisms have been identified, but our understanding of the requirements for a robust ICB response is incomplete. We have engineered an MHC I/antigen: TCR-matched panel of human NSCLC cancer and T cells to identify tumor cell-intrinsic T cell resistance mechanisms. The top differentially expressed gene in resistant tumor cells was SERPINB9. This serine protease inhibitor of the effector T cell-derived molecule granzyme B prevents caspase-mediated tumor apoptosis. Concordantly, we show that genetic ablation of SERPINB9 reverts T cell resistance of NSCLC cell lines, whereas its overexpression reduces T cell sensitivity. SERPINB9 expression in NSCLC strongly correlates with a mesenchymal phenotype. We also find that SERPINB9 is commonly amplified in cancer, particularly melanoma in which it is indicative of poor prognosis. Single-cell RNA sequencing of ICB-treated melanomas revealed that SERPINB9 expression is elevated not only in cells from post- versus pre-treatment cancers, but also in ICB-refractory cancers. In NSCLC we commonly observed rare SERPINB9-positive cancer cells, possibly accounting for reservoirs of ICB-resistant cells. While underscoring SERPINB9 as a potential target to combat immunotherapy resistance, these results suggest its potential to serve as a prognostic and predictive biomarker.
© 2022 The Author(s). Published with license by Taylor & Francis Group, LLC.

  • FC/FACS
  • Homo sapiens (Human)
  • Cancer Research
  • Immunology and Microbiology

Effects of hypoxia on antigen presentation and T cell-based immune recognition of HPV16-transformed cells.

In Frontiers in Immunology on 8 November 2022 by Mohan, N., Wellach, K., et al.

Attempts to develop a therapeutic vaccine against human papillomavirus (HPV)-induced malignancies have mostly not been clinically successful to date. One reason may be the hypoxic microenvironment present in most tumors, including cervical cancer. Hypoxia dysregulates the levels of human leukocyte antigen (HLA) class I molecules in different tumor entities, impacts the function of cytotoxic T cells, and leads to decreased protein levels of the oncoproteins E6 and E7 in HPV-transformed cells. Therefore, we investigated the effect of hypoxia on the presentation of HPV16 E6- and E7-derived epitopes in cervical cancer cells and its effect on epitope-specific T cell cytotoxicity. Hypoxia induced downregulation of E7 protein levels in all analyzed cell lines, as assessed by Western blotting. However, contrary to previous reports, no perturbation of antigen processing and presentation machinery (APM) components and HLA-A2 surface expression upon hypoxia treatment was detected by mass spectrometry and flow cytometry, respectively. Cytotoxicity assays performed in hypoxic conditions showed differential effects on the specific killing of HPV16-positive cervical cancer cells by epitope-specific CD8+ T cell lines in a donor- and peptide-specific manner. Effects of hypoxia on the expression of PD-L1 were ruled out by flow cytometry analysis. Altogether, our results under hypoxia show a decreased expression of E6 and E7, but an intact APM, and epitope- and donor-dependent effects on T cell cytotoxicity towards HPV16-positive target cells. This suggests that successful immunotherapies can be developed for hypoxic HPV-induced cervical cancer, with careful choice of target epitopes, and ideally in combination with hypoxia-alleviating measures.
Copyright © 2022 Mohan, Wellach, Özerdem, Veits, Förster, Foehr, Bonsack and Riemer.

  • FC/FACS
  • Homo sapiens (Human)
  • Immunology and Microbiology
View this product on CiteAb