Arsenic trioxide-induced cell apoptosis and cell cycle arrest are potentiated by 1,25-dihydroxyvitamin D3 in human leukemia K562 cells

Autophagy plays a pro-apoptotic role in arsenic trioxide-induced cell death of liver cancer

OBJECTIVE

The effects of arsenic trioxide (As2O3) on hepatocellular carcinoma have been documented widely. Autophagy plays dual roles in the survival and death of cancer cells. Therefore, we investigated the exact role of autophagy in As2O3-induced apoptosis in liver cancer cells.

METHODS

The viability of hepatoma cells was determined using the MTT assay with or without fetal bovine serum. The rate of apoptosis in liver cancer cells treated with As2O3 was evaluated using flow cytometry, Hoechst 33258 staining, and TUNEL assays. The rate of autophagy among liver cancer cells treated with As2O3 was detected using immunofluorescence, Western blot assay and transmission electron microscopy.

RESULTS

Upon treatment with As2O3, the viability of HepG2 and SMMC-7721 cells was decreased in a time- and dose-dependent manner. The apoptosis rates of both liver cancer cell lines increased with the concentration of As2O3, as shown by flow cytometry. Apoptosis in liver cancer cells treated with As2O3 was also shown by the activation of the caspase cascade and the regulation of Bcl-2/Bax expression. Furthermore, As2O3 treatment induced autophagy in liver cancer cells; this finding was supported by Western blot, immunofluorescence of LC3-II and beclin 1, and transmission electron microscopy. In liver cancer cells, As2O3 inhibited the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signal pathway that plays a vital role in both apoptosis and autophagy. The PI3K activator SC-79 partially reversed As2O3-induced autophagy and apoptosis. Furthermore, inhibiting autophagy with 3-methyladenine partially reversed the negative effects of As2O3 on cell viability. Serum starvation increased autophagy and amplified the effect of As2O3 on cell death.

CONCLUSION

As2O3 induces apoptosis and autophagy in liver cancer cells. Autophagy induced by As2O3 may have a proapoptotic effect that helps to reduce the viability of liver cancer cells. This study provides novel insights into the effects of As2O3 against liver cancer. Please cite this article as: Deng ZT, Liang SF, Huang GK, Wang YQ, Tu XY, Zhang YN, Li S, Liu T, Cheng BB. Autophagy plays a pro-apoptotic role in arsenic trioxide-induced cell death of liver cancer. J Integr Med. 2024; 22(3): 295-302.

An overview of arsenic trioxide-involved combined treatment algorithms for leukemia: basic concepts and clinical implications

Arsenic trioxide is a first-line treatment drug for acute promyelocytic leukemia, which is also effective for other kinds of leukemia. Its side effects, however, limit its clinical application, especially for patients with complex leukemia symptoms. Combination therapy can effectively alleviate these problems. This review summarizes the research progress on the combination of arsenic trioxide with anticancer drugs, vitamin and vitamin analogs, plant products, and other kinds of drugs in the treatment of leukemia. Additionally, the new progress in arsenic trioxide-induced cardiotoxicity was summarized. This review aims to provide new insights for the rational clinical application of arsenic trioxide.

Parthenolide and arsenic trioxide co-trigger autophagy-accompanied apoptosis in hepatocellular carcinoma cells

Although arsenic trioxide (ATO) shows a strong anti-tumor effect in the treatment of acute promyelocytic leukemia, it does not benefit patients with hepatocellular carcinoma (HCC). Thus, combination therapy is proposed to enhance the efficacy of ATO. Parthenolide (PTL), a natural compound, selectively eradicates cancer cells and cancer stem cells with no toxicity to normal cells. In this study, we chose PTL and ATO in combination and found that nontoxic dosage of PTL and ATO co-treatment can synergistically inhibit the in vitro and in vivo proliferation activity of HCC cells through suppressing stemness and self-renewal ability and inducing mitochondria-dependent apoptosis. More importantly, USP7-HUWE1-p53 pathway is involved in PTL enhancing ATO-induced apoptosis of HCC cell lines. Meanwhile, accompanied by induction of apoptosis, PTL and ATO evoke autophagic activity via inhibiting PI3K/Akt/mTOR pathway, and consciously controlling autophagy can improve the anti-HCC efficacy of a combination of PTL and ATO. In short, our conclusion represents a novel promising approach to the treatment of HCC.