Introduction

The Janus Kinase (JAK) and Signal Transducer and Activator of Transcription (STAT) pathways play important roles in the pathogenesis of T cell lymphoma in humans and up-regulated STAT3 expression and activity are associated with worse clinical outcome in humans. No studies have evaluated the JAK-STAT signaling pathway in T cell lymphoma of dogs. The objective of this study was to evaluate if STAT3 pathway is deregulated in T cell lymphoma in dogs. We aim to assess the expression, activation, and cellular localization of STAT3 and mitogen-activated protein kinase ERK1/2 in T cell lymphoma of dogs.

Methods

Retrospective analysis of T cell lymphoma in dogs, including patient characteristics and treatment, and immunohistochemistry. Biopsy samples of 26 client-owned dogs diagnosed with T cell lymphoma by histopathology were evaluated in this study.

Results

There was a significantly higher percentage of STAT3 (62.47%) and p-STAT3 (11.29%) immunolabelled cells in canine T cell lymphoma samples compared with canine normal lymph nodes (STAT3=46.7%; p-STAT3=5.47%), (p<0.05). In STAT3 immunolabelled cells, STAT3 has higher nuclear expression in lymphoma samples than in normal lymph nodes. We are currently investigating mitogen-activated kinase ERK1/2 activation in T cell lymphoma of dogs.

Conclusion

Compared with the normal canine lymph node, T cell lymphoma of dogs has up-regulated STAT3 pathway. Our results support future investigation of JAK inhibitors in the treatment of T cell lymphoma in dogs.

Funding Information

University of Wisconsin-Madison Companion Animal Fund.