Ayman Oweida - Academia.edu (original) (raw)

Papers by Ayman Oweida

Cells

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has recently emerged in China an... more The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has recently emerged in China and caused a disease called coronavirus disease 2019 (COVID-19). The virus quickly spread around the world, causing a sustained global outbreak. Although SARS-CoV-2, and other coronaviruses, SARS-CoV and Middle East respiratory syndrome CoV (MERS-CoV) are highly similar genetically and at the protein production level, there are significant differences between them. Research has shown that the structural spike (S) protein plays an important role in the evolution and transmission of SARS-CoV-2. So far, studies have shown that various genes encoding primarily for elements of S protein undergo frequent mutation. We have performed an in-depth review of the literature covering the structural and mutational aspects of S protein in the context of SARS-CoV-2, and compared them with those of SARS-CoV and MERS-CoV. Our analytical approach consisted in an initial genome and transcriptome analysis, fol...

Journal for ImmunoTherapy of Cancer

BackgroundSquamous cell lung cancer (SCLC) is the second most common type of lung cancer. Treatme... more BackgroundSquamous cell lung cancer (SCLC) is the second most common type of lung cancer. Treatment is complicated due to the lack of mutated molecular targets.1 Radiotherapy (RT) is commonly used to treat SCLC, but relapse and tumor progression are common. The combination of immunotherapy (IT) with RT can enhance the effect observed with RT alone.2 Effective combination of IT and RT requires an understanding of the pathways that synergize to enhance tumor cell kill in SCLC. Our lab has identified Toll-like receptor 3 (TLR3) as a molecule that is regulated by RT and can be targeted with IT. Toll-like receptors serve a crucial role against tumor cells by activating innate and adaptive immune responses that boost antitumor immunity.3 4 TLR3 is the only receptor whose molecular mechanism functions independent of MyD88, leading to NF-κB mediated apoptosis.5 We hypothesized that increased TLR3 expression would be associated with improved response to RT. We further hypothesized that RT ca...

Neuro-Oncology

BACKGROUND Diffuse intrinsic pontine glioma (DIPG) and diffuse midline glioma (DMG) are metastati... more BACKGROUND Diffuse intrinsic pontine glioma (DIPG) and diffuse midline glioma (DMG) are metastatic diseases, as demonstrated by early convection-enhanced delivery (CED) clinical trials in which prolonged local tumor control can sometimes be achieved, but fatal disseminated disease then develops. We hypothesize that improvements in treatment of both focal disease and the entire neuraxis are necessary for long-term survival, and patient-derived xenograft (PDX) models can help advance these efforts. METHODS We used a BT245 murine orthotopic DIPG PDX model for this work. We developed a protocol and specialized platform to deliver craniospinal irradiation (CSI) with a pontine boost. We separately compared intratumoral drug concentration by CED and intraperitoneal delivery. In our CED model, mice receive gemcitabine 60 ug x1 in 15 ul at 0.5 ul/minute through a stepped catheter design with silica tubing extending 2mm beyond a 27G needle. RESULTS Mice receiving CSI (4 Gy x2d) plus boost (4 ...

Journal of Clinical Oncology

101 Background: Cancers of the head and neck (HNC) represent some of the most debilitating and ag... more 101 Background: Cancers of the head and neck (HNC) represent some of the most debilitating and aggressive tumors. Radiotherapy (RT) is the primary treatment modality for locally advanced HNC, but less than 50% of patients treated with RT survive to 5 years. Clinical trials with the immune checkpoint inhibitor PD-L1 have shown considerable promise, but on its own has only yielded a 20% response rate. RT has the potential to transform the tumor microenvironment promoting infiltration of T-cells in poorly immunogenic tumors and activating T-cells in tumors with pre-existing T-cell populations. We hypothesized that the combination of PD-L1 inhibition with radiation can enhance therapeutic efficacy through re-invigoration of exhausted T-cells. Methods: Tumor cells were injected into the right buccal mucosa. Treatment was initiated when established tumors were observed. Forty mice per tumor model were randomized to IgG2b control, anti PD-L1, RT alone or RT+anti PD-L1. Anti PD-L1 was start...

Cancer Immunology, Immunotherapy

Experimental and Molecular Therapeutics

Journal of Clinical Oncology

70 Background: Head and neck tumors are highly enriched in regulatory T cells which dampen the re... more 70 Background: Head and neck tumors are highly enriched in regulatory T cells which dampen the response to radiotherapy by creating an immune-inhibitory microenvironment. We explored mechanisms of Treg infiltration and assessed their modulation by RT in murine models of HNSCC. Methods: Mechanisms of Treg infiltration were investigated in murine HNSCC tumors using whole genome sequencing and flow cytometry. Mice were treated with anti-CTLA-4, anti-CD-25 and/or anti-PD-L1 alone and in combination with RT. Tumor growth and survival were assessed. Flow cytometry was used to assess phenotypic and functional changes in intratumoral T cell populations. Multiplex ELISA was performed for assessment of cytokines. RNA Sequencing was performed to interrogate mechanisms of response and resistance to treatment. Results: Treatment with anti-CD-25 concurrently with RT led to significant tumor growth delay, enhanced T cell cytotoxicity, decreased Tregs and improved survival. In contrast CTLA-4 block...

Clinical Research (Excluding Clinical Trials)

Cancer Research

Identifying targets present in the tumor microenvironment that contribute to immune evasion has b... more Identifying targets present in the tumor microenvironment that contribute to immune evasion has become an important area of research. In this study, we identified EphB4-ephrin-B2 signaling as a regulator of both innate and adaptive components of the immune system. EphB4 belongs to receptor tyrosine kinase family that interacts with ephrin-B2 ligand at sites of cell-cell contact, resulting in bidirectional signaling. We found that EphB4-ephrin-B2 inhibition alone or in combination with radiation (RT) reduced intratumoral regulatory T cells (Tregs) and increased activation of both CD8 þ and CD4 þ Foxp3 À T cells compared with the control group in an orthotopic head and neck squamous cell carcinoma (HNSCC) model. We also compared the effect of EphB4-ephrin-B2 inhibition combined with RT with combined anti-PDL1 and RT and observed similar tumor growth suppression, particularly at early time-points. A patient-derived xenograft model showed reduction of tumor-associated M2 macrophages and favored polarization towards an antitumoral M1 phenotype following EphB4-ephrin-B2 inhibition with RT. In vitro, EphB4 signaling inhibition decreased Ki67-expressing Tregs and Treg activation compared with the control group. Overall, our study is the first to implicate the role of EphB4-ephrin-B2 in tumor immune response. Moreover, our findings suggest that EphB4-ephrin-B2 inhibition combined with RT represents a potential alternative for patients with HNSCC and could be particularly beneficial for patients who are ineligible to receive or cannot tolerate anti-PDL1 therapy. Significance: These findings present EphB4-ephrin-B2 inhibition as an alternative to anti-PDL1 therapeutics that can be used in combination with radiation to induce an effective antitumor immune response in patients with HNSCC.

Journal of Visualized Experiments

Clinical Cancer Research

Purpose: A driving factor in pancreatic ductal adenocarcinoma (PDAC) treatment resistance is the ... more Purpose: A driving factor in pancreatic ductal adenocarcinoma (PDAC) treatment resistance is the tumor microenvironment, which is highly immunosuppressive. One potent immunologic adjuvant is radiotherapy. Radiation, however, has also been shown to induce immunosuppressive factors, which can contribute to tumor progression and formation of fibrotic tumor stroma. To capitalize on the immunogenic effects of radiation and obtain a durable tumor response, radiation must be rationally combined with targeted therapies to mitigate the influx of immunosuppressive cells and fibrosis. One such target is ephrinB2, which is overexpressed in PDAC and correlates negatively with prognosis. Experimental Design: On the basis of previous studies of ephrinB2 ligand-EphB4 receptor signaling, we hypothesized that inhibition of ephrinB2-EphB4 combined with radiation can regulate the microenvironment response postradiation, leading to increased tumor control in PDAC. This hypothesis was explored using both cell lines and in vivo human and mouse tumor models. Results: Our data show this treatment regimen significantly reduces regulatory T-cell, macrophage, and neutrophil infiltration and stromal fibrosis, enhances effector T-cell activation, and decreases tumor growth. Furthermore, our data show that depletion of regulatory T cells in combination with radiation reduces tumor growth and fibrosis. Conclusions: These are the first findings to suggest that in PDAC, ephrinB2-EphB4 interaction has a profibrotic, protumorigenic role, presenting a novel and promising therapeutic target.

JNCI: Journal of the National Cancer Institute

Background Radioresistance represents a major problem in the treatment of head and neck cancer (H... more Background Radioresistance represents a major problem in the treatment of head and neck cancer (HNC) patients. To improve response, understanding tumor microenvironmental factors that contribute to radiation resistance is important. Regulatory T cells (Tregs) are enriched in numerous cancers and can dampen the response to radiation by creating an immune-inhibitory microenvironment. The purpose of this study was to investigate mechanisms of Treg modulation by radiation in HNC. Methods We utilized an orthotopic mouse model of HNC. Anti-CD25 was used for Treg depletion. Image-guided radiation was delivered to a dose of 10 Gy. Flow cytometry was used to analyze abundance and function of intratumoral immune cells. Enzyme-linked immunosorbent assay was performed to assess secreted factors. For immune-modulating therapies, anti–PD-L1, anti-CTLA-4, and STAT3 antisense oligonucleotide (ASO) were used. All statistical tests were two-sided. Results Treatment with anti-CD25 and radiation led to...

Frontiers in Immunology

Radiation therapy has been used for many years to treat tumors based on its DNA-damage-mediated a... more Radiation therapy has been used for many years to treat tumors based on its DNA-damage-mediated ability to kill cells. More recently, RT has been shown to exert beneficial modulatory effects on immune responses, such as triggering immunogenic cell death, enhancing antigen presentation, and activating cytotoxic T cells. Consequently, combining radiation therapy with immunotherapy represents an important area of research. Thus far, immune-checkpoint inhibitors targeting programmed death-ligand 1 (PD-L1), programmed cell death protein 1 (PD-1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) have been the focus of many research studies and clinical trials. The available data suggest that such immunotherapies are enhanced when combined with radiation therapy. However, treatment resistance, intrinsic or acquired, is still prevalent. Various theories as to how to enhance these combination therapies to overcome treatment resistance have been proposed. In this review, we focus on the principles surrounding radiation therapy's positive and negative effects on the tumor microenvironment. We explore mechanisms underlying radiation therapy's synergistic and antagonistic effects on immune responses and provide a base of knowledge for radio-immunology combination therapies to overcome treatment resistance. We provide evidence for targeting regulatory T cells, tumor-associated macrophages, and cancer-associated fibroblasts in combination radio-immunotherapies to improve cancer treatment.

Arquivos Brasileiros de Oftalmologia

ABSTRACT

Oral oncology, 2018

Extracapsular extension (ECE) in regional lymph nodes and positive surgical margins (PSM) are con... more Extracapsular extension (ECE) in regional lymph nodes and positive surgical margins (PSM) are considered high-risk adverse pathologic features in patients with oropharyngeal squamous cell carcinoma (OPSCC) that each constitute an indication for postoperative adjuvant chemoradiation. We identify pre-operative clinical factors that can predict post-operative ECE and/or PSM and create a nomogram to help clinical decision making. Adult patients with non-metastatic OPSCC with initial surgical treatment and confirmed HPV status diagnosed between 2010 and 2014 were selected from the National Cancer Database. Clinical staging was modified to American Joint Committee on Cancer 8th edition parameters. Logistic regression was used for multivariate analysis to identify predictors of pathologic ECE and/or PSM. 5065 patients were included. 47.5% of the 3336 HPV-positive (HPV+) patients had ECE/PSM. 40.4% of the 1729 HPV-negative (HPV-) patients with had ECE/PSM. A model was built that included ag...

Cells

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has recently emerged in China an... more The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has recently emerged in China and caused a disease called coronavirus disease 2019 (COVID-19). The virus quickly spread around the world, causing a sustained global outbreak. Although SARS-CoV-2, and other coronaviruses, SARS-CoV and Middle East respiratory syndrome CoV (MERS-CoV) are highly similar genetically and at the protein production level, there are significant differences between them. Research has shown that the structural spike (S) protein plays an important role in the evolution and transmission of SARS-CoV-2. So far, studies have shown that various genes encoding primarily for elements of S protein undergo frequent mutation. We have performed an in-depth review of the literature covering the structural and mutational aspects of S protein in the context of SARS-CoV-2, and compared them with those of SARS-CoV and MERS-CoV. Our analytical approach consisted in an initial genome and transcriptome analysis, fol...

Journal for ImmunoTherapy of Cancer

BackgroundSquamous cell lung cancer (SCLC) is the second most common type of lung cancer. Treatme... more BackgroundSquamous cell lung cancer (SCLC) is the second most common type of lung cancer. Treatment is complicated due to the lack of mutated molecular targets.1 Radiotherapy (RT) is commonly used to treat SCLC, but relapse and tumor progression are common. The combination of immunotherapy (IT) with RT can enhance the effect observed with RT alone.2 Effective combination of IT and RT requires an understanding of the pathways that synergize to enhance tumor cell kill in SCLC. Our lab has identified Toll-like receptor 3 (TLR3) as a molecule that is regulated by RT and can be targeted with IT. Toll-like receptors serve a crucial role against tumor cells by activating innate and adaptive immune responses that boost antitumor immunity.3 4 TLR3 is the only receptor whose molecular mechanism functions independent of MyD88, leading to NF-κB mediated apoptosis.5 We hypothesized that increased TLR3 expression would be associated with improved response to RT. We further hypothesized that RT ca...

Neuro-Oncology

BACKGROUND Diffuse intrinsic pontine glioma (DIPG) and diffuse midline glioma (DMG) are metastati... more BACKGROUND Diffuse intrinsic pontine glioma (DIPG) and diffuse midline glioma (DMG) are metastatic diseases, as demonstrated by early convection-enhanced delivery (CED) clinical trials in which prolonged local tumor control can sometimes be achieved, but fatal disseminated disease then develops. We hypothesize that improvements in treatment of both focal disease and the entire neuraxis are necessary for long-term survival, and patient-derived xenograft (PDX) models can help advance these efforts. METHODS We used a BT245 murine orthotopic DIPG PDX model for this work. We developed a protocol and specialized platform to deliver craniospinal irradiation (CSI) with a pontine boost. We separately compared intratumoral drug concentration by CED and intraperitoneal delivery. In our CED model, mice receive gemcitabine 60 ug x1 in 15 ul at 0.5 ul/minute through a stepped catheter design with silica tubing extending 2mm beyond a 27G needle. RESULTS Mice receiving CSI (4 Gy x2d) plus boost (4 ...

Journal of Clinical Oncology

101 Background: Cancers of the head and neck (HNC) represent some of the most debilitating and ag... more 101 Background: Cancers of the head and neck (HNC) represent some of the most debilitating and aggressive tumors. Radiotherapy (RT) is the primary treatment modality for locally advanced HNC, but less than 50% of patients treated with RT survive to 5 years. Clinical trials with the immune checkpoint inhibitor PD-L1 have shown considerable promise, but on its own has only yielded a 20% response rate. RT has the potential to transform the tumor microenvironment promoting infiltration of T-cells in poorly immunogenic tumors and activating T-cells in tumors with pre-existing T-cell populations. We hypothesized that the combination of PD-L1 inhibition with radiation can enhance therapeutic efficacy through re-invigoration of exhausted T-cells. Methods: Tumor cells were injected into the right buccal mucosa. Treatment was initiated when established tumors were observed. Forty mice per tumor model were randomized to IgG2b control, anti PD-L1, RT alone or RT+anti PD-L1. Anti PD-L1 was start...

Cancer Immunology, Immunotherapy

Experimental and Molecular Therapeutics

Journal of Clinical Oncology

70 Background: Head and neck tumors are highly enriched in regulatory T cells which dampen the re... more 70 Background: Head and neck tumors are highly enriched in regulatory T cells which dampen the response to radiotherapy by creating an immune-inhibitory microenvironment. We explored mechanisms of Treg infiltration and assessed their modulation by RT in murine models of HNSCC. Methods: Mechanisms of Treg infiltration were investigated in murine HNSCC tumors using whole genome sequencing and flow cytometry. Mice were treated with anti-CTLA-4, anti-CD-25 and/or anti-PD-L1 alone and in combination with RT. Tumor growth and survival were assessed. Flow cytometry was used to assess phenotypic and functional changes in intratumoral T cell populations. Multiplex ELISA was performed for assessment of cytokines. RNA Sequencing was performed to interrogate mechanisms of response and resistance to treatment. Results: Treatment with anti-CD-25 concurrently with RT led to significant tumor growth delay, enhanced T cell cytotoxicity, decreased Tregs and improved survival. In contrast CTLA-4 block...

Clinical Research (Excluding Clinical Trials)

Cancer Research

Identifying targets present in the tumor microenvironment that contribute to immune evasion has b... more Identifying targets present in the tumor microenvironment that contribute to immune evasion has become an important area of research. In this study, we identified EphB4-ephrin-B2 signaling as a regulator of both innate and adaptive components of the immune system. EphB4 belongs to receptor tyrosine kinase family that interacts with ephrin-B2 ligand at sites of cell-cell contact, resulting in bidirectional signaling. We found that EphB4-ephrin-B2 inhibition alone or in combination with radiation (RT) reduced intratumoral regulatory T cells (Tregs) and increased activation of both CD8 þ and CD4 þ Foxp3 À T cells compared with the control group in an orthotopic head and neck squamous cell carcinoma (HNSCC) model. We also compared the effect of EphB4-ephrin-B2 inhibition combined with RT with combined anti-PDL1 and RT and observed similar tumor growth suppression, particularly at early time-points. A patient-derived xenograft model showed reduction of tumor-associated M2 macrophages and favored polarization towards an antitumoral M1 phenotype following EphB4-ephrin-B2 inhibition with RT. In vitro, EphB4 signaling inhibition decreased Ki67-expressing Tregs and Treg activation compared with the control group. Overall, our study is the first to implicate the role of EphB4-ephrin-B2 in tumor immune response. Moreover, our findings suggest that EphB4-ephrin-B2 inhibition combined with RT represents a potential alternative for patients with HNSCC and could be particularly beneficial for patients who are ineligible to receive or cannot tolerate anti-PDL1 therapy. Significance: These findings present EphB4-ephrin-B2 inhibition as an alternative to anti-PDL1 therapeutics that can be used in combination with radiation to induce an effective antitumor immune response in patients with HNSCC.

Journal of Visualized Experiments

Clinical Cancer Research

Purpose: A driving factor in pancreatic ductal adenocarcinoma (PDAC) treatment resistance is the ... more Purpose: A driving factor in pancreatic ductal adenocarcinoma (PDAC) treatment resistance is the tumor microenvironment, which is highly immunosuppressive. One potent immunologic adjuvant is radiotherapy. Radiation, however, has also been shown to induce immunosuppressive factors, which can contribute to tumor progression and formation of fibrotic tumor stroma. To capitalize on the immunogenic effects of radiation and obtain a durable tumor response, radiation must be rationally combined with targeted therapies to mitigate the influx of immunosuppressive cells and fibrosis. One such target is ephrinB2, which is overexpressed in PDAC and correlates negatively with prognosis. Experimental Design: On the basis of previous studies of ephrinB2 ligand-EphB4 receptor signaling, we hypothesized that inhibition of ephrinB2-EphB4 combined with radiation can regulate the microenvironment response postradiation, leading to increased tumor control in PDAC. This hypothesis was explored using both cell lines and in vivo human and mouse tumor models. Results: Our data show this treatment regimen significantly reduces regulatory T-cell, macrophage, and neutrophil infiltration and stromal fibrosis, enhances effector T-cell activation, and decreases tumor growth. Furthermore, our data show that depletion of regulatory T cells in combination with radiation reduces tumor growth and fibrosis. Conclusions: These are the first findings to suggest that in PDAC, ephrinB2-EphB4 interaction has a profibrotic, protumorigenic role, presenting a novel and promising therapeutic target.

JNCI: Journal of the National Cancer Institute

Background Radioresistance represents a major problem in the treatment of head and neck cancer (H... more Background Radioresistance represents a major problem in the treatment of head and neck cancer (HNC) patients. To improve response, understanding tumor microenvironmental factors that contribute to radiation resistance is important. Regulatory T cells (Tregs) are enriched in numerous cancers and can dampen the response to radiation by creating an immune-inhibitory microenvironment. The purpose of this study was to investigate mechanisms of Treg modulation by radiation in HNC. Methods We utilized an orthotopic mouse model of HNC. Anti-CD25 was used for Treg depletion. Image-guided radiation was delivered to a dose of 10 Gy. Flow cytometry was used to analyze abundance and function of intratumoral immune cells. Enzyme-linked immunosorbent assay was performed to assess secreted factors. For immune-modulating therapies, anti–PD-L1, anti-CTLA-4, and STAT3 antisense oligonucleotide (ASO) were used. All statistical tests were two-sided. Results Treatment with anti-CD25 and radiation led to...

Frontiers in Immunology

Radiation therapy has been used for many years to treat tumors based on its DNA-damage-mediated a... more Radiation therapy has been used for many years to treat tumors based on its DNA-damage-mediated ability to kill cells. More recently, RT has been shown to exert beneficial modulatory effects on immune responses, such as triggering immunogenic cell death, enhancing antigen presentation, and activating cytotoxic T cells. Consequently, combining radiation therapy with immunotherapy represents an important area of research. Thus far, immune-checkpoint inhibitors targeting programmed death-ligand 1 (PD-L1), programmed cell death protein 1 (PD-1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) have been the focus of many research studies and clinical trials. The available data suggest that such immunotherapies are enhanced when combined with radiation therapy. However, treatment resistance, intrinsic or acquired, is still prevalent. Various theories as to how to enhance these combination therapies to overcome treatment resistance have been proposed. In this review, we focus on the principles surrounding radiation therapy's positive and negative effects on the tumor microenvironment. We explore mechanisms underlying radiation therapy's synergistic and antagonistic effects on immune responses and provide a base of knowledge for radio-immunology combination therapies to overcome treatment resistance. We provide evidence for targeting regulatory T cells, tumor-associated macrophages, and cancer-associated fibroblasts in combination radio-immunotherapies to improve cancer treatment.

Arquivos Brasileiros de Oftalmologia

ABSTRACT

Oral oncology, 2018

Extracapsular extension (ECE) in regional lymph nodes and positive surgical margins (PSM) are con... more Extracapsular extension (ECE) in regional lymph nodes and positive surgical margins (PSM) are considered high-risk adverse pathologic features in patients with oropharyngeal squamous cell carcinoma (OPSCC) that each constitute an indication for postoperative adjuvant chemoradiation. We identify pre-operative clinical factors that can predict post-operative ECE and/or PSM and create a nomogram to help clinical decision making. Adult patients with non-metastatic OPSCC with initial surgical treatment and confirmed HPV status diagnosed between 2010 and 2014 were selected from the National Cancer Database. Clinical staging was modified to American Joint Committee on Cancer 8th edition parameters. Logistic regression was used for multivariate analysis to identify predictors of pathologic ECE and/or PSM. 5065 patients were included. 47.5% of the 3336 HPV-positive (HPV+) patients had ECE/PSM. 40.4% of the 1729 HPV-negative (HPV-) patients with had ECE/PSM. A model was built that included ag...