Use of fluorescence in situ hybridization to detect Felis catus papillomavirus type 2 in feline Bowenoid in situ carcinomas

Exploring the link between viruses and cancer in companion animals: a comprehensive and comparative analysis

Currently, it is estimated that 15% of human neoplasms globally are caused by infectious agents, with new evidence emerging continuously. Multiple agents have been implicated in various forms of neoplasia, with viruses as the most frequent. In recent years, investigation on viral mechanisms underlying tumoral transformation in cancer development and progression are in the spotlight, both in human and veterinary oncology. Oncogenic viruses in veterinary medicine are of primary importance not only as original pathogens of pets, but also in the view of pets as models of human malignancies. Hence, this work will provide an overview of the main oncogenic viruses of companion animals, with brief notes of comparative medicine.

Papillomaviral skin diseases of humans, dogs, cats and horses: A comparative review. Part 2: Pre-neoplastic and neoplastic diseases

Papillomaviruses (PVs) are well recognized to cause pre-neoplastic and neoplastic diseases in humans. Similarly, there is increasing evidence that PVs play a significant role in the development of pre-neoplastic and neoplastic diseases of the haired skin of dogs and cats, and the mucosa of horses. As the mechanisms by which PVs cause neoplasia are well studied in humans, it is valuable to compare the PV-induced neoplasms of humans with similar PV-associated neoplasms in the companion animal species. In the second part of this comparative review, the pre-neoplastic and neoplastic diseases thought to be caused by PVs in humans, dogs, cats, and horses are described. This includes PV-induced cutaneous plaques, cutaneous squamous cell carcinomas (SCCs) and mucosal SCCs within the four species. The review concludes with a discussion about the potential use of vaccines to prevent PV-induced diseases of dogs, cats, and horses.

Infectious Causes of Neoplasia in the Domestic Cat

Simple Summary

Increasingly, cancers are being linked to infections with viruses, bacteria, and parasites in human medicine. This review summarises the current literature regarding neoplasia occurring in association with infectious diseases in domestic cats. To date, most studies have focused on the role of viruses, especially feline leukaemia virus and feline immunodeficiency virus in association with lymphoma, or the role of papillomavirus in cutaneous and oral neoplasms in cats. Recently, there has been a focus on a potential role of mouse mammary tumour virus in feline mammary carcinoma and lymphoma and studies assessing the potential role of gammaherpes virus and hepadnaviruses in feline neoplasia. Additionally, there has been some focus on potential bacterial and parasitic associations with neoplasia; including reports assessing potential associations between Helicobacter species and gastrointestinal neoplasms, and case reports of neoplasia in association with Platynosomum fastosum and Opisthorchis viverrini.

Abstract

In recent years, growing attention has been paid to the influence/role of infectious diseases in tumour development and progression. Investigations have demonstrated that some infectious organisms can have a direct role in the development of neoplasia, whereas others can predispose to neoplasia by alterations in the immune response, or by creating a pro-inflammatory environment. Feline leukaemia virus was one of the first infectious agents recognised as an oncogenic organism, and along with feline immunodeficiency virus has received the most attention. Since the discovery of this retrovirus, several other organisms have been associated with neoplastic processes in cats, these include gammaherpes virus, mouse mammary tumour virus, papillomaviruses, hepadnavirus, Helicobacter species, and the parasitic infections Platynosomum fastosum and Opisthorchis viverrini. This review summarises the findings to date.

Papillomaviruses in Domestic Cats

Papillomaviruses (PVs) are well established to cause hyperplastic papillomas (warts) in humans and animals. In addition, due to their ability to alter cell regulation, PVs are also recognized to cause approximately 5% of human cancers and these viruses have been associated with neoplasia in a number of animal species. In contrast to other domestic species, cats have traditionally been thought to less frequently develop disease due to PV infection. However, in the last 15 years, the number of viruses and the different lesions associated with PVs in cats have greatly expanded. In this review, the PV life cycle and the subsequent immune response is briefly discussed along with methods used to investigate a PV etiology of a lesion. The seven PV types that are currently known to infect cats are reviewed. The lesions that have been associated with PV infections in cats are then discussed and the review finishes with a brief discussion on the use of vaccines to prevent PV-induced disease in domestic cats.

Felis catus Papillomavirus Types 1, 2, 3, 4, and 5 in Feline Bowenoid in Situ Carcinoma: An In Situ Hybridization Study

Several studies based on histopathology or molecular investigations suggest a causal relation between Felis catus papillomavirus (FcaPV-2) infection and bowenoid in situ carcinoma (BISC) in cats. Nevertheless, data on distribution of viral DNA for different F. catus papillomavirus types (FcaPV-1, 2, 3, 4, 5) in precancerous skin lesions are lacking. In this study, incisional and excisional skin biopsies from 18 cats with BISC were investigated for the presence of FcaPV DNA by quantitative polymerase chain reaction (qPCR) and chromogenic in situ hybridization (CISH) using specific probes to detect each of the FcaPVs that have been identified so far. By qPCR analysis, 15 of 18 samples were positive for FcaPV-2, 2 were positive for FcaPV-4, and 1 sample was negative for all FcaPVs studied. Two cases were positive for FcaPV-5 by qPCR only. FcaPV-1 and FcaPV-3 were not detected by either method. CISH positivity for FcaPV-2 and FcaPV-4 was 100% concordant with qPCR. FcaPV-2 CISH signal was observed as nuclear dots within grouped neoplastic keratinocytes in 12 BISCs and in the perilesional skin of 9 biopsies. In 3 of these 9 cases, the signal was not observed within the BISC. FcaPV-4 CISH positivity was detected only within BISCs in 2 cases. The overall rate of concordance for FcaPV detection between PCR and CISH was 97.8%. This study suggests that CISH is a reliable method to detect FcaPV-2 and FcaPV-4 infection in cats and provides useful information on the type, rate, and localization of infected cells.