This study investigated different methods of EGFR (Epithelial Growth Factor Receptor) targeting in feline squamous cell carcinoma with the ultimate aim of establishing a large animal model of human...

Tooth resorption (TR) in domestic cats is a common and painful disease characterised by the loss of mineralised tissues from the tooth. Due to its progressive nature and unclear aetiology the only treatment currently available is to extract affected teeth. To gain insight into TR pathogenesis, we characterised the transcriptomic changes involved in feline TR by sequencing RNA extracted from 14 teeth (7 with and 7 without signs of resorption) collected from 11 cats. A paired comparison of teeth from the same cat with and without signs of resorption identified 1,732 differentially expressed genes, many of which were characteristic of osteoclast activity and differentiation, in particular matrix metalloproteinase 9 (MMP9). MMP9 expression was confirmed by qPCR and immunocytochemistry of odontoclasts located in TR lesions. A hydroxamate-based MMP9 inhibitor reduced both osteoclast formation and resorption activity while siRNA targeting MMP9 also inhibited osteoclast differentiation although had little effect on resorption activity. Overall, these results suggest that increased MMP9 expression is involved in the progress of TR pathogenesis and that MMP9 may be a potential therapeutic target in feline TR.

Members of the epidermal growth factor receptor (EGFR/ERBB) gene family are frequently dysregulated in a range of human cancers, and therapeutics targeting these proteins are in clinical use. We hypothesized that similar pathways are involved in feline and canine tumours and that the same drugs may be of clinical use in veterinary patients. We investigated EGFR and ERBB2 targeting using a panel of feline and canine cell lines. EGFR and ERBB2 were targeted with siRNAs or tyrosine kinase inhibitors (TKIs) and their effect on cellular proliferation, colony formation and migration was investigated in vitro. Here we report that EGFR and ERBB2 combined siRNA targeting produced synergistic effects in feline and canine cell lines similar to that reported in human cell lines. We conclude that dual EGFR and ERBB2 targeting using TKIs should be further evaluated as a potential new therapeutic strategy in feline head and neck and mammary tumours and canine mammary tumours.

In line with Sustainable Development Goal 9 (sustainable industrialisation and innovation), environmentally responsible engineering designs in modern robotics should consider factors such as renewability, sustainability, and biodegradability. The robotics sector is growing at an exponential rate and, as a consequence, its contribution to e-waste is a growing concern. Our work contributes to the technological development of caninoid necro-robots, robots that are built from the skeletons of deceased dogs. The already formed skeletal structures of deceased dogs (and other animals) are ideal natural material replacements for synthetic robotic architectures such as plastics, metals, and composites. Since dog skeletons are disarticulated, simple but effective methods need to be developed to rearticulate their bodies. The canine head is essentially a large end effector, but its mandible is held together by a fibrocartilaginous joint (symphysis) that degrades at a higher rate than the bone itself. The degradation of the symphysis would ordinarily negate the utility of a canine head as a necro-robotic end effector; however, in this research, we consider simple methods of mandible reinforcement to circumvent this problem. Our research uses 3D scans of a real canine head, which is modelled using the finite element method to ascertain optimal geometrical reinforcements for the mandible. The full head structures and their reinforcements are printed and adhesively connected to determine the most effective reinforcing strategy of the mandible. Here, we elucidate geometrically selected reinforcement designs that are evidenced through mechanical testing, to successfully increase the stiffness of a disarticulated mandible.

Feline oral squamous cell carcinoma (FOSCC) is the most common oral malignancy, characterised by aggressive local invasion, frequent bone involvement, and poor prognosis. The limited availability of well‐characterised in vitro models has hindered the understanding of tumour heterogeneity and invasive behaviour. This study aimed to establish and comparatively characterise a panel of FOSCC cell lines derived from tumours with and without documented bone invasion to identify intrinsic biological differences. Four FOSCC cell lines were evaluated for epithelial identity, growth kinetics, clonogenicity, migratory capacity and chemosensitivity. All cell lines retained epithelial characteristics, with consistent expression of epithelial markers; however, variation in cytokeratin‐19 and vimentin suggested phenotypic heterogeneity and partial epithelial‐mesenchymal plasticity. The cell lines demonstrated distinct proliferation rates, doubling times, and clonogenic capacities. Morphologically, these cells displayed varying degrees of peripheral filopodial activity. Functional assays further revealed substantial migratory capacity under both serum‐supplemented and serum‐free conditions, with differences across cell lines. Chemosensitivity profiling showed heterogeneous responses to targeted and cytotoxic agents, highlighting cell line‐specific differences in drug susceptibility and potential intrinsic drug responsiveness. These findings demonstrate that FOSCC cell lines possess distinct biological properties consistent with phenotypic differences. The observed heterogeneity underscores the potential relevance of tumour origin in shaping functional behaviour and highlights the value of using multiple, well‐characterised cell line models to better represent disease diversity. This study provides a comprehensive comparative characterisation of four FOSCC cell lines, including a newly established model, and establishes a baseline resource for future mechanistic and translational investigations in feline and comparative oncology.

The cover image, by M. E. Gray et al., is based on the Original Article Dual targeting of EGFR and ERBB2 pathways produces a synergistic effect on cancer cell proliferation and migration in vitro, DOI: 10.1111/vco.12230.