Background: Prostate cancer (PCa) is one of the most common malignant diseases among male patients. Although androgen deprivation therapy remains the main treatment for PCa, most patients would inevitably progress to castration-resistant PCa, which is the main cause of cancer-related deaths. Thus, novel antitumor agents are urgently needed. Recent studies demonstrated that aloperine (ALO) as a natural alkaloid showed antitumor effects in other cancer types. However, the biological function and underlying mechanisms of ALO in PCa have not been investigated.
Methods: PCa cell lines including LNCaP, PC3 and DU145 were cultured and treated with ALO. Cell Counting Kit-8 assay, colony formation assay, apoptosis assay and cell cycle assay were conducted to assess the biological role of ALO. In addition, a PCa subcutaneous xenograft mouse model was established to evaluate the role of ALO in terms of proliferation and apoptosis in vivo. We further measured the protein expression levels of p-Akt/Akt, p-ERK/ERK, c-Myc, cleaved caspase 3, p21, p53, Bcl-2 and Bax using the Western blot 48 h after ALO treatment of PCa cells.
Results: ALO effectively inhibited the cell viability of PCa by inducing cell cycle arrest via the activation of the p53/p21 pathway and triggering apoptosis in vitro and in vivo. ALO also inhibited phosphorylation of Akt and ERK protein kinases and activated cleaved caspase 3 while exerting antiproliferation function through inducing apoptosis and cell cycle arrest in PCa cells.
Conclusion: Based on our findings, we conclude that ALO could suppress the tumor growth and promote cell apoptosis and cell cycle arrest in PCa cells, which indicated that ALO could act as a novel therapeutic agent in treatment of human PCa.
Keywords: aloperine; apoptosis; cell cycle; proliferation; prostate cancer.