RESUMEN

OBJECTIVE: The present research aims to report cytotoxic and antimigratory activities of the oxidized form of brazilin, i.e., brazilein, and the effects of the combination of brazilein-doxorubicin on MCF-7/HER2 cells. METHODS: The MTT assay was conducted to test the cytotoxic activity, while flow cytometry with PI and PI-annexin V staining were respectively performed for cell cycle and apoptosis analyses. Migration and invasion analyses were assessed via Boyden chamber assay, while HER2, Rac1, p120, MMP2, and MMP9 protein levels were determined by immunoblotting and gelatin zymography. Molecular docking of ligands with HER2, Src, PI3Kα, PI3KΔ, and PI3Kγ proteins was evaluated using MOE 2010. RESULTS: The MTT assay showed that the IC50 value of brazilein against MCF-7/HER2 cells was 51 ± 2.1 µM. Moreover, brazilein and its combination with doxorubicin-induced G2/M accumulation and apoptosis. Combination of brazilein-doxorubicin inhibited cell migration and tended to decrease HER2, Rac1, p120, MMP2, and MMP9 protein expression levels. Based on our molecular docking study, the docking score of brazilein with PI3Kγ is comparable to that of the native ligand. CONCLUSION: Taken together, a combination of brazilein-doxorubicin exhibited synergistic cytotoxic and antimigratory effects on MCF-7/HER2 cells.
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Asunto(s)

Antineoplásicos , Metaloproteinasa 9 de la Matriz , Antineoplásicos/farmacología , Apoptosis , Benzopiranos , Doxorrubicina/farmacología , Humanos , Indenos , Metaloproteinasa 2 de la Matriz , Simulación del Acoplamiento Molecular

RESUMEN

Purpose: Breast cancer cells with overexpression of HER2 are known to be more aggressive, invasive, and resistant to chemotherapeutic agent. Brazilin, the major compound in the Caesalpinia sappan L. (CS) heartwood, has been studied for it's anticancer activity. The purpose of this study was to investigate the cytotoxic and antimigratory activity of brazilin (Bi) in combination with doxorubicin (Dox) on MCF-7/HER2 cells. Methods: Cytotoxic activities of Bi individually and in combination with Dox were examined by MTT assay. Synergistic effects were analyzed by combination index (CI). Apoptosis and cell cycle profiles were observed by using flow cytometry. Migrating and invading cells were observed by using a Boyden chamber assay. Levels of MMP2 and MMP9 activity were observed by using a gelatin zymography assay. Levels of HER2, Bcl-2, Rac1, and p120 protein expression were observed by using an immunoblotting assay. Results: The results of the MTT assay showed that Bi inhibited MCF-7/HER2 cell growth in a dose-dependent manner with an IC50 of 54 ± 3.7 µM. Furthermore, the combination of Bi and Dox showed a synergistic effect (CI <1). Flow cytometric analysis of Bi and its combination with Dox showed cellular accumulation in the G2/M phase and induction of apoptosis through suppression of Bcl-2 protein expression. In the Boyden chamber assay, gelatin zymography, and subsequent immunoblotting assay, the combination Bi and Dox inhibited migration, possibly through downregulation of MMP9, MMP2, HER2, Rac1, and p120 protein expression. Conclusion: We conclude that Bi enhanced cytotoxic activity of Dox and inhibited migration of MCF-7/HER2 cells. Therefore, we believe that it has strong potential to be developed for the treatment of metastatic breast cancer with HER2 overexpression.