Low dosage of arsenic trioxide inhibits vasculogenic mimicry in hepatoblastoma without cell apoptosis

Research progress on arsenic, arsenic-containing medicinal materials, and arsenic-containing preparations: clinical application, pharmacological effects, and toxicity

Introduction: The toxicity of arsenic is widely recognized globally, mainly harming human health by polluting water, soil, and food. However, its formulations can also be used for the clinical treatment of diseases such as leukemia and tumors. Arsenic has been used as a drug in China for over 2,400 years, with examples such as the arsenic-containing drug realgar mentioned in Shennong's Herbal Classic. We have reviewed references on arsenic over the past thirty years and found that research has mainly focused on clinical, pharmacological, and toxicological aspects. Results and Discussion: The finding showed that in clinical practice, arsenic trioxide is mainly used in combination with all-trans retinoic acid (ATRA) at a dose of 10 mg/d for the treatment of acute promyelocytic leukemia (APL); realgar can be used to treat acute promyelocytic leukemia, myelodysplastic syndrome, and lymphoma. In terms of pharmacology, arsenic mainly exerts anti-tumor effects. The dosage range of the action is 0.01-80 μmol/L, and the concentration of arsenic in most studies does not exceed 20 μmol/L. The pharmacological effects of realgar include antiviral activity, inhibition of overactivated lactate dehydrogenase, and resistance to malaria parasites. In terms of toxicity, arsenic is toxic to multiple systems in a dose-dependent manner. For example, 5 μmol/L sodium arsenite can induce liver oxidative damage and promote the expression of pro-inflammatory factors, and 15 μmol/L sodium arsenite induces myocardial injury; when the concentration is higher, it is more likely to cause toxic damage.

Transcatheter arterial chemoembolization using CalliSpheres beads loaded with arsenic trioxide for unresectable large or huge hepatocellular carcinoma: a prospective study

OBJECTIVES

To determine the safety and efficacy of transcatheter arterial chemoembolization with CalliSpheres® beads loaded with arsenic trioxide (CBATO-TACE) in the first-line treatment of patients with large (5 cm ≤ maximum diameter < 10 cm) or huge (maximum diameter ≥ 10 cm) hepatocellular carcinoma (HCC).

METHODS

Patients were randomly allocated to the CBATO-TACE group and the conventional transcatheter arterial chemoembolization (cTACE) group. The primary endpoint was progression-free survival (PFS). The secondary endpoint was overall survival (OS), treatment response, and treatment-related adverse events (TRAEs). The extrahepatic collateral arteries, liver function, and liver fibrosis after the first TACE were also evaluated.

RESULTS

From September 2018 to September 2020, a total of 207 patients who underwent TACE were consecutively enrolled in this study. The median PFS was 9.5 months (range: 8.0 - 11.0) in the CBATO group, which was significantly longer than that in the cTACE group (6.0 months, range: 4.0-6.0) (p < 0.0001). Patients in the CBATO group had a median OS of 22 months (range: 20.0 - 27.0) compared with 16 months (range: 15.0 - 20.0) in the cTACE group (p = 0.0084). The most common TRAEs were fever (p = 0.043), and nausea and vomiting (p = 0.002), which were more observed in the cTACE group. In addition, the progressive disease time, pulmonary metastasis rate (p = 0.01), the mean number of extrahepatic collateral arteries (p = 0.01), and average number of TACE sessions (p = 0.025) were significantly decreased in the CBATO group.

CONCLUSIONS

CBATO-TACE achieved better therapeutic outcomes and similar safety profile compared to cTACE in large or huge HCC patients. Furthermore, CBATO-TACE was able to reduce extrahepatic collateral arteries production and extrahepatic lung metastasis.

CLINICAL RELEVANCE STATEMENT

Our study showed that CalliSpheres® beads loaded with arsenic trioxide (CBATO-TACE) were effective and safe for the treatment of large and giant HCC. In addition, CBATO-TACE can reduce lateral hepatic branch artery formation and extrahepatic pulmonary metastasis, which provides a new treatment approach for unresectable HCC.

KEY POINTS

• We compare long-term efficacy and safety of transcatheter arterial chemoembolization with CalliSpheres® beads loaded with arsenic trioxide (CBATO-TACE) and conventional transcatheter arterial chemoembolization (cTACE) in patients with large (5 cm ≤ maximum diameter < 10 cm) or huge HCC (maximum diameter ≥ 10 cm). • Compared with cTACE, CBATO-TACE significantly improved therapeutic outcomes, overall survival, and progression-free survival in patients with large or huge HCC. The safety assessment suggested that CBATO-TACE is a safe treatment that improves the quality of life and has good treatment adherence.

Overcoming the therapeutic resistance of hepatomas by targeting the tumor microenvironment

Hepatocellular carcinoma (HCC) accounts for the majority of primary liver cancers and is the third leading cause of cancer-related mortality worldwide. Multifactorial drug resistance is regarded as the major cause of treatment failure in HCC. Accumulating evidence shows that the constituents of the tumor microenvironment (TME), including cancer-associated fibroblasts, tumor vasculature, immune cells, physical factors, cytokines, and exosomes may explain the therapeutic resistance mechanisms in HCC. In recent years, anti-angiogenic drugs and immune checkpoint inhibitors have shown satisfactory results in HCC patients. However, due to enhanced communication between the tumor and TME, the effect of heterogeneity of the microenvironment on therapeutic resistance is particularly complicated, which suggests a more challenging research direction. In addition, it has been reported that the three-dimensional (3D) organoid model derived from patient biopsies is more intuitive to fully understand the role of the TME in acquired resistance. Therefore, in this review, we have focused not only on the mechanisms and targets of therapeutic resistance related to the contents of the TME in HCC but also provide a comprehensive description of 3D models and how they contribute to the exploration of HCC therapies.

Arsenic trioxide-loaded CalliSpheres: In vitro study of drug release and antitumor activity, and in vivo study of pharmacokinetics, treatment efficacy and safety in liver cancer

The aim of the present study was to investigate the arsenic trioxide (ATO) loading/releasing efficiency of CalliSphere beads (CBs), as well as the in vitro anticancer activity, in vivo pharmacokinetics, treatment efficacy and safety of ATO-eluting CBs in liver cancer. The ATO loading and releasing efficiencies in CBs were evaluated. Furthermore, cell viability, invasion, apoptosis, VEGF expression and MMP9 expression were determined in liver cancer cells treated with ATO-eluting CBs or ATO solution. Rabbit liver models were established and underwent TACE with ATO-eluting CBs or ATO/lipiodol emulsion. Subsequently, their ATO pharmacokinetics were determined and macroscopic/microscopic examinations were conducted. In vitro, CB-loaded ATO increased during 40 min with an optimal loading efficiency of 23.0±2.5%, and released ATO rapidly within the first 30 min (31.40±10.0%) then slowed down within the latter 48 h (47.20±4.70%). ATO-eluting CBs exhibited decreased cell viability to some extent and similar invasive cell count, apoptosis rate, VEGF and MMP9 levels compared with ATO solution at various concentrations and time-points. In vivo, ATO concentration was lower in plasma, but higher in tumor tissues, and necrosis was more complete in tumor tissue while milder in normal liver parenchyma after rabbit liver was embolized with ATO-eluting CBs compared with ATO/lipiodol emulsion. ATO-eluting CBs may be a novel and promising therapeutic option in treating liver cancer.

Cancer-associated fibroblast regulation of tumor neo-angiogenesis as a therapeutic target in cancer

Adequate blood supply is essential for tumor survival, growth and metastasis. The tumor microenvironment (TME) is dynamic and complex, comprising cancer cells, cancer-associated stromal cells and their extracellular products. The TME serves an important role in tumor progression. Cancer-associated fibroblasts (CAFs) are the principal component of stromal cells within the TME, and contribute to tumor neo-angiogenesis by altering the proteome and degradome. The present paper reviews previous studies of the molecular signaling pathways by which CAFs promote tumor neo-angiogenesis and highlights therapeutic response targets. Also discussed are potential strategies for antitumor neo-angiogenesis to improve tumor treatment efficacy.

Arsenic trioxide induces apoptosis and the formation of reactive oxygen species in rat glioma cells

Background

Arsenic trioxide (As₂O₃) has a dramatic therapeutic effect on acute promyelocytic leukemia (APL) patients. It can also cause apoptosis in various tumor cells. This study investigated whether As₂O₃ has an antitumor effect on glioma and explored the underlying mechanism.

Results

MTT and trypan blue assays showed that As₂O₃ remarkably inhibited growth of C6 and 9 L glioma cells. Cell viability decreased in glioma cells to a greater extent than in normal glia cells. The annexin V-FITC/PI and Hoechest/PI staining assays revealed a significant increase in apoptosis that correlated with the duration of As₂O₃ treatment and occurred in glioma cells to a greater extent than in normal glial cells. As₂O₃ treatment induced reactive oxygen species (ROS) production in C6 and 9 L cells in a time-dependent manner. Cells pretreated with the antioxidant N-acetylcysteine (NAC) showed significantly lower As₂O₃-induced ROS generation. As₂O₃ significantly inhibited the expression of the anti-apoptotic gene Bcl-2, and upregulated the proapoptotic gene Bax in both C6 and 9 L glioma cells in a time-dependent manner.

Conclusions

As₂O₃ can significantly inhibit the growth of glioma cells and it can induce cell apoptosis in a time- and concentration-dependent manner. ROS were found to be responsible for apoptosis in glioma cells induced by As₂O₃. These results suggest As₂O₃ is a promising agent for the treatment of glioma.