Abstract: Background and purpose: Pterostilbene is a natural antioxidant, whose role in retinoblastoma remains unclear. The aim of this study is to probe the effects of pterostilbene on the proliferation, apoptosis and autophagy in retinoblastoma WERI-Rb-1 cell lines. Methods: Cell counting kit-8 (CCK-8) assays were used to analyze the effects of pterostilbene on the proliferation of WERI-Rb-1 cells. Apoptosis rate was determined by Annexin V/PI. Autophagic vacuoles were observed by acridine orange staining. LC3 and P62 protein expressions were determined using Western blot. Results: Pterostilbene significantly inhibited the proliferation of WERI-Rb-1 cells (P<0.01). The cell viability were (93.02±0.47)%, (55.10±2.04)% and (30.33±1.45)% after WERI-Rb-1 cells were treated with 25, 50 and 100 μmol/L pterostilbene for 24 h, and the cell viability were (88.38±3.70)%, (53.37±1.17)%, (29.60±1.05)% after WERI-Rb-1 cells were treated with 50 μmol/L pterostilbene for 12, 24 and 48 h. Pterostilbene induced cell apoptosis (P<0.01), the apoptosis rates of control group, 24 h treated group and 48 h treated group were (4.08±0.79)%, (13.44±2.12)% and (23.49±2.01)%. Pterostilbene induced autophagy of WERI-Rb-1 cells, increased LC3 expression, downregulated P62 expression and increased the number of autophagic vacuoles in WERI-Rb-1 cells (P<0.01). 3-MA and Beclin1 were able to rescue pterostilbene-induced cell death (P<0.01). After 3-MA was used to blunt autophagosome formation, the apoptosis rate markedly decreased in 3-MA+pterostilbene-treated cells compared with cells treated with pterostilbene alone [(12.97±2.09)% vs (8.35±1.11)%], and after siRNA was used to knockdown Beclin1, the apoptosis rate had the same change [(13.80±2.19)% vs (9.62±0.52)%]. Conclusion: Pterostilbene can inhibit the proliferation of WERI-Rb-1 cells and induce cell apoptosis via autophagy activation.

Key words: Pterostilbene, Retinoblastoma, Cell apoptosis, Cell proliferation, Cell autophagy