SurvivinT34A increases the therapeutic efficacy of arsenic trioxide in mouse hepatocellular carcinoma models

Synergistic anti-tumor effects of arsenic trioxide and blue LED irradiation on human osteosarcoma

Arsenic trioxide (ATO) has been well recognized as an anti-tumor agent for various human cancers. Recently, the blue light emitting diodes (LEDs)-based therapy has also been demonstrated to be potential therapeutic strategies for several cancers. However, the combination effects of ATO and blue LED on tumor suppression are still unclear. In this study, we determined whether combination of ATO and blue LED irradiation at 470 nm in wavelength exhibited superior anti-tumor activity in human osteosarcoma (OS). We observed that combination treatments of ATO and blue LED much more significantly decreased the percentages of proliferative cells, and increased apoptotic rate compared with any single treatments in U-2 OS cells. Furthermore, we found suppression of cell migration and invasion were much more pronounced in ATO plus blue LED treated group than single treated groups. Moreover, reactive oxygen species (ROS) assay and immunostaining of γ-H2A.X and p53 indicated that the combined treatments resulted in further markedly increases in ROS accumulation, DNA damage and p53 activity. Taken together, our study demonstrated synergistical anti-tumor effects of combined treatments of ATO and blue LED on human OS cells, which were associated with an increased ROS accumulation, DNA damaged mediated p53 activation.

Metformin ameliorates arsenic trioxide hepatotoxicity via inhibiting mitochondrial complex I

Arsenic trioxide (ATO) is a well-accepted chemotherapy agent in managing promyelocytic leukemia. ATO often causes severe health hazards such as hepatotoxicity, dermatosis, neurotoxicity, nephrotoxicity and cardiotoxicity. The production of reactive oxygen species, (ROS) play a significant role in ATO-induced hepatotoxicity. The oral hypoglycemic drug, metformin, is considered to be a potential novel agent for chemoprevention in the treatment of cancer. Moreover, metformin has also been shown to have hepatoprotective effects. In the present study, we demonstrated that metformin protected normal hepatocytes from ATO-induced apoptotic cell death in vitro and in vivo. Gene expression screening revealed that glucose metabolism might be related to the metformin-induced protective effect on ATO-treated AML12 cells. The metformin-promoted or induced glycolysis was not responsible for the protection of AML12 cells from ATO-induced apoptotic cell death. Instead, metformin increased the intracellular NADH/NAD+ ratio by inhibiting mitochondrial respiratory chain complex I, further decreasing the intracellular ROS induced by ATO. Treatment with low glucose or rotenone, a mitochondrial respiratory chain complex I inhibitor, also protected AML12 cells from ATO-induced apoptotic cell death. We show for the first time that metformin protects the hepatocyte from ATO by regulating the mitochondrial function. With its properties of chemoprevention, chemosensitization and the amelioration of liver damage, metformin has great prospects for clinical application other than type 2 diabetes mellitus (T2DM).

The antitumor effects of arsenic trioxide in mantle cell lymphoma via targeting Wnt/β‑catenin pathway and DNA methyltransferase-1

Mantle cell lymphoma (MCL) is an aggressive non‑Hodgkin lymphoma (NHL) with poor prognosis. The rapid progression and frequently relapse make it urgent to identify therapeutic agents with potent antitumor effect. Increasing evidence indicated that dysregulation of Wnt/β‑catenin pathway and abnormal methylation appeared to promote tumorigenesis. Arsenic trioxide (As2O3, ATO) has been reported effective in many hematologic malignancies in recent studies, however, the mechanism and effects of ATO in MCL still need further research. In this study, ATO was shown to promote apoptosis and to inhibit cell viability in MCL cell lines, whereas, the expression of DNA methyltransferase-1 (DNMT-1), β‑catenin and the downstream molecules of Wnt/β‑catenin pathway such as c‑myc, cyclin D1 and MMP7 were all decreased in a dose-dependent manner with ATO. ATO also attenuated upregulation of β‑catenin after LiCl stimulation and provided synergistic effect with 5-azacytidine (5-azaC) on the DNMT-1 inhibition. The results indicated that ATO may suppress MCL by targeting Wnt/β‑catenin pathway and DNMT-1. These findings may guide drug usage of ATO in clinical therapy for MCL.

Novel multi-substituted benzyl acridone derivatives as survivin inhibitors for hepatocellular carcinoma treatment

Sorafenib was the only small-molecule drug approved by FDA for treatment of the advanced hepatocellular carcinoma (HCC). Recent study indicated that YM155 was a promising agent for HCC cells with high survivin expression, however, the antitumor activity needs to be further improved. Based on molecular docking and rational design method, a series of multi-substituted benzyl acridone derivatives were designed and synthesized. MTT assay indicated that some of the synthesized compounds displayed better antiproliferative activity against HepG2 cells than YM155. Later study indicated that the representive compound 8u may directly interact with survivin protein and induce HepG2 cells apoptosis, which is different from YM155. In addition, ADME property was predicted in silico, and it performed well. Moreover, in vivo preliminary experiments showed that 8u may be a good lead compound in the treatment of HCC.