STAT3 Expression and Activity are Up-Regulated in Diffuse Large B Cell Lymphoma of Dogs

Area of Science:

• Veterinary Oncology
• Molecular Biology
• Cancer Research

Background:

• The Janus Kinase (JAK) and Signal Transducer and Activator of Transcription (STAT) pathways are implicated in human diffuse large B cell lymphoma (DLBCL).
• Upregulated STAT3 is linked to poorer clinical outcomes in human DLBCL.
• The JAK-STAT pathway in canine DLBCL has not been previously investigated.

Purpose of the Study:

• To investigate the STAT3 pathway's deregulation in canine DLBCL.
• To evaluate STAT3 and mitogen-activated protein kinase ERK1/2 expression, activation, and cellular localization in canine DLBCL.

Main Methods:

• Retrospective analysis of 43 client-owned dogs with histopathologically diagnosed DLBCL.
• Immunohistochemistry and Western blot analysis to assess protein expression and activation.
• Comparison with normal canine lymph nodes.

Main Results:

• Canine DLBCL samples showed increased STAT3 and phosphorylated STAT3 (p-STAT3) immunolabeling compared to normal lymph nodes.
• STAT3 exhibited higher nuclear expression in lymphoma cells.
• Activation of mitogen-activated kinase ERK1/2 was also found to be upregulated in canine DLBCL.

Conclusions:

• Diffuse large B cell lymphoma in dogs exhibits an upregulated STAT3 pathway compared to normal canine lymph nodes.
• These findings support further research into JAK inhibitors for treating canine DLBCL.
• The study highlights the potential of targeting the JAK-STAT pathway in canine lymphoma.