Shuqi Zhao,Meifeng Chen,Zhu Yu,Thi Thai Hoa Pham,Shutian Mo,Yongfei He,Tianyi Liang,Wenlong Cao,Chuangye Han
BackgroundBreast cancer (BC) is the most common type of cancer affecting females. It is also a leading cause of cancer-related death in women worldwide.MethodsSonodynamic therapy (SDT) is an emerging therapeutic strategy for cancer treatment. SDT ensures non-invasive penetration of deep tumors and results in activation of non-toxic sonosensitizers administered in deep tumor sites to become cytotoxic. It has been reported that 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD) has a significant anti-tumor effect against various cancer types including BC. However, DMDD is hydrophobic. Therefore, a one-step encapsulation method was used in the current study to construct zeolitic imidazole frameworks-8 (ZIF-8) loaded with DMDD and sonosensitizer chlorin e6 (Ce6). ZIF-8 was further modified by coating it with a biomimetic cell membrane to improve targeted delivery.ResultsIn vitro and in vivo results indicated that the nanomedicines had great biocompatibility properties and targeting ability. The nanocomposite exhibited a higher release rate under an acidic tumor microenvironment. The tumor killing effect of reactive oxygen species (ROS) generated from Ce6 and inhibition of tumor growth was enhanced after ultrasound (US) treatment, which might be caused by the increase in apoptosis rate.ConclusionsThese findings show that the combination of nanomedicine and SDT provides a potential therapeutic method for BC.Keywords: Breast cancer (BC), 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD), metal-organic framework, sonodynamic therapy, ZIF-8 nanoparticles
Several studies have suggested a potential antitumor effect of 2-dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD). To further understand the mechanism of action of this compound, we investigated its effect on the phosphatidylinositol-3-kinase (PI3K)/serine–threonine kinase (Akt)/mammalian target of rapamycin (mTOR) signaling pathway. We show that DMDD application significantly inhibited the proliferation of breast cancer cell lines MDA-MB-231 and ER-α positive MCF-7. Furthermore, DMDD application resulted in increased intracellular reactive oxygen species (ROS) levels, apoptosis and autophagy, whereas it downregulated the expression of PI3K, Akt and mTOR mRNA and proteins, and increased the expression of LC3II/I and p62 proteins. In a mouse breast cancer xenograft model, DMDD inhibited tumor growth. Expression analyses suggest that ROS levels were higher in DMDD treated tumor tissues, whereas immunohistochemical analyses suggest that apoptotic cells were more prevalent in the DMDD treated group compared to the control group. Taken together, our results suggest that the molecular mechanism of action of DMDD may involve the enhancement of breast cancer autophagy through the PI3K/Akt/mTOR signaling pathway by mediating ROS expression.