Bottlenose dolphins are a cosmopolitan species, found in all tropical and temperate oceans worldwide. Dolphins, similar to other mammals, can develop cancers known as squamous cell carcinomas, which arise in cells that comprise the thin, outermost layer of skin (epidermis), as well as those that line internal body cavities such as in the mouth and the surface of the tongue. These cancers can become locally invasive if left untreated and sometimes metastasize to additional sites, leading to severe and potentially fatal complications. Some carcinomas may be initiated by specific viral genes which act as oncogenes (i.e., genes which induce tumor development), which we will be investigating.
In conjunction with Drs. Michael Walsh and Craig Pelton (also in the Department of Comparative, Diagnostic and Population Medicine in the CVM at UF and members of UF’s Aquatic Animal Stranding Network), along with Dr. Megan Horowitz (a marine veterinarian and UF CVM graduate student), we are investigating how benign oral and genital tumors (papillomas) observed in wild and captive common bottlenose dolphins (Tursiops truncatus) ultimately develop into squamous cell carcinomas. Currently, little is known concerning what role viruses (such as papillomaviruses or herpesviruses) may play in the development of these cancers, if there are additional cellular and/or environmental factors that may be facilitating the transition of these papillomas to carcinomas, and how to effectively treat cancerous tumors with therapeutic approaches that may help alleviate disease in dolphins. As bottlenose dolphins are an important sentinel species of marine environments, developing a comprehensive understanding of this novel disease is critical in evaluating population and ecosystem health.
The main objectives of this project are to:
- Determine the viral etiology of orogenital papillomas and cancers in dolphins through metagenomics
- Create new diagnostics for virus detection based on metagenomic results
- Use viral data to direct new clinical therapeutics to reduce tumor progression and mitigate disease
By identifying a viral basis in certain oral and genital papillomas and/or additional synergistic factors (e.g., upregulation of hormonal receptors) that may facilitate their transition to squamous cell carcinomas, such studies will hopefully provide insights into how to develop new and effective treatment options to eliminate or reduce the burden of this emerging disease in bottlenose dolphins.