Arsenic trioxide-induced growth arrest of human hepatocellular carcinoma cells involving FOXO3a expression and
1Institute of Medical Biotechnology, Soochow University, Suzhou, 215007, China.
Abstract:
Human hepatocellular carcinoma (HCC) remains incurable with current therapies, and novel biologically based therapies are urgently needed. Arsenic agents have long been used as anticancer agents in traditional Chinese medicine. In this study, to evaluate the effect of As(2)O(3) on HCC cells, we investigate cell growth inhibition, cell cycle arrest, and the molecular mechanism after As(2)O(3) treatment in human HCC cells in vitro. We detected the proliferation of HCC cells by the Cell Counting Kit and FACS/Calibur Flow Cytometer and analyzed the expression and localization of FOXO3a by Western blotting Analysis and Cell Fractionation. Furthermore, we study the Akt activation after As(2)O(3) treatment and the HCC cells proliferation after combination of As(2)O(3) with PI3K inhibitor Wortmannin. As(2)O(3) significantly inhibited the proliferation of all the three HCC cell lines (SMMC7721, HepG2, Hep3B) tested in this study in a dose-dependent manner. Western blotting revealed that treatment HCC cells HepG2 with As(2)O(3) resulted in the increasing of FOXO3a expression and triggered phosphorylation of FOXO3a at the Thr(32) residue decrease. This FOXO3a accumulation correlated well with the As(2)O(3)-induced reduction of active Akt. Nuclear and cytoplasmic protein extracts isolated from the HCC cell line HepG2 revealed that the amount of nuclear FOXO3a was increased by treatment with As(2)O(3), whereas the amount of cytoplasmic FOXO3a was decreased. Both As(2)O(3) and PI3K/Akt inhibitor Wortmannin induced cell cycle arrest. However, compared with As(2)O(3) alone, PI3K inhibitor Wortmannin combined with As(2)O(3) enhanced the antitumor effect of As(2)O(3) through induction of apoptosis. These findings suggest that As(2)O(3) at a clinically safe concentration may be an effective chemotherapeutic agent, and that As(2)O(3) and PI3K/Akt inhibitor Wortmannin may synergize for HCC cells. Taken together, the present study may suggest a specific molecular mechanism by which HCC cell lines are susceptible to the As(2)O(3) therapy through FOXO3a expression and localization.
Insights
Arsenic trioxide (As(2)O(3)) effectively inhibits hepatocellular carcinoma (HCC) cell growth by increasing FOXO3a expression and reducing Akt activity. Combining As(2)O(3) with Wortmannin enhances its antitumor effects, suggesting a novel therapeutic strategy for HCC.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Hepatocellular carcinoma (HCC) lacks effective treatments.
- Arsenic compounds show promise as anticancer agents.
Purpose of the Study:
- To investigate the effects of arsenic trioxide (As(2)O(3)) on HCC cell proliferation, cell cycle, and molecular mechanisms.
- To explore the potential synergy between As(2)O(3) and PI3K/Akt inhibitor Wortmannin.
Main Methods:
- Cell Counting Kit and Flow Cytometry for proliferation.
- Western blotting and Cell Fractionation for protein analysis.
- Treatment with As(2)O(3) and Wortmannin in HCC cell lines.
Main Results:
- As(2)O(3) significantly inhibited HCC cell proliferation in a dose-dependent manner.
- As(2)O(3) increased FOXO3a expression and nuclear localization, correlating with decreased Akt activity.
- Combination therapy with Wortmannin enhanced As(2)O(3)'s antitumor effect via apoptosis induction.
Conclusions:
- As(2)O(3) is a potential chemotherapeutic agent for HCC, acting through FOXO3a and Akt pathways.
- Synergistic effects observed between As(2)O(3) and Wortmannin suggest a promising combination therapy for HCC.
