Anticancer Effects of BAF312 (Siponimod) in Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) is a lethal disease that is the fifth leading cause of cancer-related death in women. BAF312 (siponimod) is a potent and selective sphingosine-1-phosphate (S1P) receptor modulator that has been approved as a treatment for multiple sclerosis. In addition to its immunomodulatory action, BAF312 shows preclinical antitumor effects in several cancer types. This study sought to determine whether BAF312 had anticancer properties against EOC using in vitro and in vivo models.

EOC cell lines A2780, SKOV3ip1, A2780-CP20, and SKOV3-TR were treated with BAF312 and tested for cell proliferation, apoptosis, and migration using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, fluorescence-activated cell sorting, and migration assays. We investigated the expression of sphingosine-1-phosphate receptor 1 (S1PR1) in most EOC cell lines through western blot analysis. To investigate potential mechanisms, western blot analysis was used to assess the expression of AKT serine/threonine kinase 1 (AKT) and extracellular-regulated kinase (ERK) after BAF312 treatment. We also created poly(D,L-lactide-co-glycolide) nanoparticles encapsulating BAF312 (PLGA-NP-BAF312) for in vivo therapy. The average size and zeta potential of PLGA-NP-BAF312 were determined using dynamic light scattering. The therapeutic efficacy of PLGA-NP-BAF312 was tested in an A2780 tumor-bearing orthotopic mouse model of EOC.

S1PR1 was overexpressed in most EOC cell lines. BAF312 significantly reduced cell proliferation and migration while inducing significant apoptosis in all EOC cell lines. PLGA-NP-BAF312 treatment significantly reduced tumor weights in A2780 tumor-bearing mice. Furthermore, the anticancer effects of BAF312 were associated with reduced phosphorylation of ERK and AKT.

Our findings show that BAF312 has significant anticancer effects in EOC cells by inhibiting the ERK and AKT pathways, and might potentially be used to treat EOCs.