Introduction

Canine mammary tumors (CMT) are frequently diagnosed and share many similar features with human breast cancer, thus serving as an excellent clinical model for potential precision treatment’s discovery. PI3K/AKT/mTOR intracellular signaling is a relevant cell cycle regulatory pathway, but mutations are commonly observed in CMT. We searched a model to evaluate the effectiveness of certain chemotherapeutic treatments using 3D cell culture, due to the cells’ ability to organize themselves in a three-dimensional way, allowing the pharmacological performance of the medicine to be more authentic.

Methods

Primary cell culture was established by trypsin enzymatic disaggregation of tumor fragments from a female dog Grade 2 Mixed Tumor Carcinoma. Cells were cultured in Matrigel using 3D on top method. Formed organoids were submitted to 72-hour interval treatments using 5 and 10 µM concentration of Erlotinib, Cetuximab and Carboplatin (gold standard).

Results

Both 5 and 10 µM Erlotinib treated organoids showed significant morphological changes. After 72 hours, 10 µM Erlotinib treated organoids showed complete degradation and death, proving effectiveness of this drug. No visible changes were observed in the other treatments.

Conclusion

The EGFR inhibitors Cetuximab or Erlotinib were used as a precision treatment for PI3K/AKT/mTOR pathway mutations. Our results suggest Erlotinib was more effective than the other treatments. Therefore, it proved to be a feasible and easily reproduced model on a case-by-case basis, directed towards precision treatment.

Funding Information

São Paulo Research Foundation (FAPESP)