ABSTRACT Canine large‐cell alimentary lymphoma (LCAL) is an aggressive malignancy with limited effective treatment options and a poor prognosis. In a preliminary drug screening study using three canine LCAL cell lines (CLC, Ema, and Nody‐1), the taxane cabazitaxel (CBZ) was identified as a promising candidate drug. This study aimed to evaluate the antitumour effects of CBZ in vitro and in vivo and determine its potential as a novel therapeutic candidate for canine LCAL. Cell viability, tubulin polymerisation, cell cycle distribution, and apoptosis were assessed in CLC, Ema, and Nody‐1 cells following treatment with CBZ or vehicle control. In addition, the effect of CBZ was evaluated in a xenotransplantation mouse model established using CLC cells. CBZ reduced cell viability across all cell lines in a dose‐dependent manner, with sub‐nanomolar half‐maximal inhibitory concentrations. A tubulin polymerisation assay demonstrated that CBZ increased polymerised tubulin levels, indicating microtubule stabilisation. CBZ treatment induced G2/M cell cycle arrest and significantly increased apoptotic cell populations, accompanied by decreased procaspase‐3 levels and increased cleaved caspase‐3 expression. In vivo, CBZ treatment reduced ascites accumulation and significantly prolonged survival relative to the vehicle control. These findings suggest that CBZ induces G2/M cell cycle arrest and caspase‐dependent apoptosis through tubulin stabilisation and suppresses tumour progression in vivo. CBZ represents a promising therapeutic candidate for canine LCAL.
Sakai et al. (Mon,) studied this question.