Aim
Investigate the anti-tumour effect of lapatinib on HER2-positive cPC cell lines.
Background
Canine prostatic carcinoma (cPC) is a urogenital tumour with a poor prognosis, for which no effective treatment has been established. Recently, it has been shown that human epidermal growth factor receptor type 2 (HER2) is overexpressed in cPC cells; however, the efficacy of HER2-targeted therapy remains unclear.
Conclusion
Lapatinib exerts anti-tumour effects on cPC cells by inhibiting HER-2 signalling.
Methods
Two cell lines (muPC and bePC) were established from two dogs with cPC and the effects of lapatinib treatment on cell proliferation, apoptosis, and HER2 downstream signalling were investigated. Furthermore, muPC was used to generate tumour-bearing mice, and the anti-tumour effects of lapatinib were examined in vivo.
Results
Lapatinib treatment inhibited the proliferation and phosphorylation of Erk1/2 and Akt, which are downstream signals of HER2. Furthermore, the TUNEL assay showed that lapatinib induced apoptosis in both cell lines. The muPC-engrafted nude mouse model showed that lapatinib significantly inhibited tumour growth and increased the area of necrotic tumour tissue compared to the vehicle-treated groups.