Oncolytic viruses (OVs) have emerged as a promising anticancer treatment. OVs selectively infect, replicate in, and kill tumor cells. Oncolytic viral therapy occurs in two phases: an initial phase where the virus mediates direct oncolysis of tumor cells, and a second phase where an induced post-oncolytic immune response continues to mediate tumor destruction and retards progression of the disease. For a long time, the therapeutic efficacy was thought to depend mainly on the direct viral oncolysis based on their tumor selective replication and killing activities. But the post-oncolytic anti-tumor activity induced by the OV therapy is also a key factor for an efficient therapeutic activity. The topic adresses various strategies how to optimize OVs anti-tumor activity.

Epigenetics is defined as the study of modifications of the genome, heritable during cell division that does not involve changes in DNA sequences. Up to date, epigenetic modifications involve at least three general mechanisms regulating gene expression: histone modifications, DNA methylation, and non-coding RNAs (ncRNAs). For the past two decades, an explosion in our interest and understanding of epigenetic mechanisms has been seen. This mainly based on the influence that epigenetic alterations have on an amazing number of biological processes, such as gene expression, imprinting, programmed DNA rearrangements, germ line silencing, developmentally cued stem cell division, and overall chromosomal stability and identity. It has become also evident that the constant exposure of living organisms to environment factors affects their genomes through epigenetic mechanisms. Viruses infecting animal cells are thought to play central roles in shaping the epigenetic scenario of infected cells. In this context it has become obvious that knowing the impact that viral infections have on the epigenetic control of their host cells will certainly lead to a better understanding of the interplay viruses have with animal cells. In fact, DNA viruses use host transcription factors as well as epigenetic regulators in such a way that they affect epigenetic control of gene expression that extends to host gene expression. At the same time, animal cells employ mechanisms controlling transcription factors and epigenetic processes, in order to eliminate viral infections. In summary, epigenetic mechanisms are involved in most virus-cell interactions. We now know that some viruses exhibit epigenetic immune evasion mechanisms to survive and propagate in their host; however, there is still much ambiguity over these epigenetic mechanisms of viral immune evasion, and most of the discovered mechanisms are still incomplete. Other animal viruses associated to cancer often deregulate cellular epigenetic mechanisms, silencing cellular tumor-suppressor genes and/or activating either viral or host cell oncogenes. In addition, in several cancers the down-regulation of tumor suppressor protein-coding genes and ncRNAs with growth inhibitory functions, such as miRNAs, have been closely linked to the presence of cell CpG island promoter hypermethylation. The goal of the aforementioned Research Topic is to bring together the key experimental and theoretical research, linking state-of-the-art knowledge about the epigenetic mechanisms involved in animal virus-cell interactions.

Overcoming Ovarian Cancer Chemoresistance presents non-overlapping review chapters that discuss the state of the field in overcoming chemoresistance of ovarian cancer and treatment options before and following recurrence, considering the genetic makeup of the ovarian cancer patient and her tumor. With the uptake of both germline and somatic gene testing, clinicians can obtain a more comprehensive understanding of ovarian tumors and this book provides information to link the genetic makeup of a tumor (or patient) with the best available treatment. The book discusses topics such as strategies to fight chemo-resistance in ovarian cancer, circulating DNA as a monitor of response, BRCA mutations, ovarian cancer stem cells, immunotherapy and vaccines. Additionally, it brings a list of promising agents at clinical and pre-clinical stage that will impact the treatment in the near future. This book is a valuable source for cancer researchers, oncologists and several members of biomedical field who need to understand how to battle chemoresistance in ovarian cancer. - Provides a comprehensive view of both biological and genetic determinants of resistance, as well as technical approaches to monitor response - Discusses genetic reversions as a unique alteration and a new field of study - Includes a chapter on upcoming and promising agents that are in the pre-clinical and early clinical space, to set the stage for future directions in the field

Cancer immunotherapy, including immune checkpoint inhibitors (ICIs) and chimeric antigen receptor T-cell (CAR-T) therapy, has revolutionized the paradigm in cancer treatment. However, the clinical outcome of immunotherapy varies considerably among patients and only a minority of patients achieve long-term clinical benefits. This is largely attributed to the fact that existing cancer immunotherapies, which concentrate on several classical targets (CTAL-4, PD-1/PD-L1, etc.) and limited types of immune cell populations (T cells), are insufficient to cope with the complexity of highly heterogeneous tumor microenvironment (TME). This calls for more efforts to not only expand our toolbox for manipulating anticancer immunity but also diversify our combinational strategies. To this end, it is urgent to deeper our understanding of cancer immunotherapy by using both experimental and computational methodologies from multi-scale perspectives: 1) novel targets from either tumor cells or non-tumor cells within TME (e.g., tumor intrinsic resistance drivers, new immune checkpoints, neoantigens), 2) in-depth characterization of more immune cell populations (e.g., macrophages, Tregs, B cells) and their interactions and dynamics within TME, 3) landscape of actionable targets in patient populations for combination design. These efforts will open the avenue of rational design of combinational immunotherapies, allowing researchers and clinicians to design novel targeting therapeutics or to optimally orchestrate combinatory strategies aiming to surmount resistance mechanisms and improve clinical outcomes.

This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.

This book is a printed edition of the Special Issue "The Tumor Microenvironment of High Grade Serous Ovarian Cancer" that was published in Cancers

Nucleic Acid Nanotheranostics: Biomedical Applications offers a comprehensive overview of improvements and new trends in fabrication of nanostructures as theranostic multifunctional carriers in gene therapy. With a strong focus on medical applications (comprising diagnosis, therapy and imaging), the book also examines gene therapy in an individual patient's cells or tissues to treat genetic diseases. Sections cover Biomedical and Diagnostic applications of Nucleic Acids, Biologic and Synthetic Advanced Nanostructures for nucleic acid delivery, and important considerations of nanomedicine. This book is a valuable guide for materials scientists, physicians, chemists and engineers, but is also ideal for clinicians wishing to expand their knowledge. - Provides a unique source of knowledge (theoretical as well as practical) on nanotheranostic materials for gene therapy at all levels and related scientific areas - Covers the pros and cons related to viral and nanomaterial-based delivery of nucleic acids in terms of biosafety, carrier selection, synthesis and bioimaging - Presents the only book to include an analysis of nanoformulations approved for clinical use

Comprehensive Toxicology, Third Edition, Fifteen Volume Set discusses chemical effects on biological systems, with a focus on understanding the mechanisms by which chemicals induce adverse health effects. Organized by organ system, this comprehensive reference work addresses the toxicological effects of chemicals on the immune system, the hematopoietic system, cardiovascular system, respiratory system, hepatic toxicology, renal toxicology, gastrointestinal toxicology, reproductive and endocrine toxicology, neuro and behavioral toxicology, developmental toxicology and carcinogenesis, also including critical sections that cover the general principles of toxicology, cellular and molecular toxicology, biotransformation and toxicology testing and evaluation. Each section is examined in state-of-the-art chapters written by domain experts, providing key information to support the investigations of researchers across the medical, veterinary, food, environment and chemical research industries, and national and international regulatory agencies. Thoroughly revised and expanded to 15 volumes that include the latest advances in research, and uniquely organized by organ system for ease of reference and diagnosis, this new edition is an essential reference for researchers of toxicology. Organized to cover both the fundamental principles of toxicology and unique aspects of major organ systems Thoroughly revised to include the latest advances in the toxicological effects of chemicals on the immune system Features additional coverage throughout and a new volume on toxicology of the hematopoietic system Presents in-depth, comprehensive coverage from an international author base of domain experts