Kdm2b promotes cell viability by enhancing DNA damage response in canine hemangiosarcoma

We found that lysine-specific demethylase 2b (Kdm2b) was highly expressed in HSA cell lines compared to normal canine endothelial cells. Silencing of Kdm2b in HSA cells resulted to increased cell death in vitro by inducing apoptosis through the inactivation of the DNA repair pathways and accumulation of DNA damage. Kdm2b silencing in tumor xenografts results to decreased tumor sizes compared to the control. Treatment of GSK-J4, a histone demethylase inhibitor, also induced apoptosis and cell death. In addition, GSK-J4 treatment decreases tumor sizes. Therefore, we demonstrate that Kdm2b acts as an oncogene in HSA by enhancing the DNA damage response. Moreover, we show that histone demethylase inhibitor GSK-J4 can be used as a therapeutic alternative to doxorubicin for HSA treatment. mRNA expression profiles of normal canine endothelial cells and a canine hemangiosarcoma cell line with/without Kdm2b knockdown.