The Importance of the Tumor Microenvironment and Hypoxia in Delivering a Precision Medicine Approach to Veterinary Oncology

Canine Mammary Tumors: Classification, Biomarkers, Traditional and Personalized Therapies

In recent years, many studies have focused their attention on the dog as a proper animal model for human cancer. In dogs, mammary tumors develop spontaneously, involving a complex interplay between tumor cells and the immune system and revealing several molecular and clinical similarities to human breast cancer. In this review, we summarized the major features of canine mammary tumor, risk factors, and the most important biomarkers used for diagnosis and treatment. Traditional therapy of mammary tumors in dogs includes surgery, which is the first choice, followed by chemotherapy, radiotherapy, or hormonal therapy. However, these therapeutic strategies may not always be sufficient on their own; advancements in understanding cancer mechanisms and the development of innovative treatments offer hope for improved outcomes for oncologic patients. There is still a growing interest in the use of personalized medicine, which should play an irreplaceable role in the research not only in human cancer therapy, but also in veterinary oncology. Moreover, immunotherapy may represent a novel and promising therapeutic option in canine mammary cancers. The study of novel therapeutic approaches is essential for future research in both human and veterinary oncology.

The Role of the Hypoxia-Related Unfolded Protein Response (UPR) in the Tumor Microenvironment

Despite our understanding of the unfolded protein response (UPR) pathways, the crosstalk between the UPR and the complex signaling networks that different cancers utilize for cell survival remains to be, in most cases, a difficult research barrier. A major problem is the constant variability of different cancer types and the different stages of cancer as well as the complexity of the tumor microenvironments (TME). This complexity often leads to apparently contradictory results. Furthermore, the majority of the studies that have been conducted have utilized two-dimensional in vitro cultures of cancer cells that were exposed to continuous hypoxia, and this approach may not mimic the dynamic and cyclic conditions that are found in solid tumors. Here, we discuss the role of intermittent hypoxia, one of inducers of the UPR in the cellular component of TME, and the way in which intermittent hypoxia induces high levels of reactive oxygen species, the activation of the UPR, and the way in which cancer cells modulate the UPR to aid in their survival. Although the past decade has resulted in defining the complex, novel non-coding RNA-based regulatory networks that modulate the means by which hypoxia influences the UPR, we are now just to beginning to understand some of the connections between hypoxia, the UPR, and the TME.

In Vivo Computing for Smart Tumor Targeting in Taxicab-Geometry Vasculature

This paper investigates the tumor microenvironment regulated by densely interconnected capillaries, resulting in the distribution of tumor-induced biological gradient field (BGF) in taxicab-geometry vasculature (TGV). We aim to improve the efficiency of tumor targeting with the knowledge of BGF in TGV, which is facilitated by a swarm of magnetic nanorobots. An external system observes and records the nanorobot swarm (NS) reaction to the BGF. Then the NS is controlled to move toward the potential tumor location by an external magnetic field. In this way, the BGF formed under the constraint of TGV is the objective function to be optimized, where the tumor center corresponds to the maximum value. The high-risk tissue area is the domain of the objective function, while the NS plays the role of a computing agent. Subsequently, we propose the coordinate gradient descent (CGD) targeting strategy for NS steering. This strategy estimates the BGF in the direction perpendicular to the propagation direction of NS to improve the efficiency of tumor detection. In addition, it considers the limited lifespan of NS in vivo, where a memory step-size mechanism (MSM) is utilized to reduce the targeting time. We use computational experiments to show that the CGD strategy yields higher tumor-targeting probabilities than the brute-force search and the original gradient-descent-inspired targeting strategy for the BGF subject to TGV.

A Comparative View on Molecular Alterations and Potential Therapeutic Strategies for Canine Oral Melanoma

Canine oral melanoma (COM) is a highly aggressive tumour associated with poor prognosis due to metastasis and resistance to conventional anti-cancer therapies. As with human mucosal melanoma, the mutational landscape is predominated by copy number aberrations and chromosomal structural variants, but differences in study cohorts and/or tumour heterogeneity can lead to discordant results regarding the nature of specific genes affected. This review discusses somatic molecular alterations in COM that result from single nucleotide variations, copy number changes, chromosomal rearrangements, and/or dysregulation of small non-coding RNAs. A cross-species comparison highlights notable recurrent aberrations, and functionally grouping dysregulated proteins reveals unifying biological pathways that may be critical for oncogenesis and metastasis. Finally, potential therapeutic strategies are considered to target these pathways in canine patients, and the benefits of collaboration between science, medical, and veterinary communities are emphasised.