Typhonium flagelliforme extract induce apoptosis in breast cancer stem cells by suppressing survivin

Abstract

Context: Breast cancer stem cells (bCSCs) are a small population of cancer-initiating cells within breast cancer, characterized as CD44+ CD24–/low. bCSCs develop apoptosis resistance by expressing survivin and suppressing caspase-9 and caspase-3 expression. Typhonium flagelliforme tuber extract (TFTe) can induce apoptosis in several types of cancer cells; however, the effects of TFTe to induce the bCSCs remain unclear. Aims: This study aimed to investigate the effects of TFTe on apoptosis induction in bCSCs through the suppression of survivin and the exhibition of caspase-9 and caspase-3. Settings and Design: This study employed a posttest only, control group design. Subjects and Methods: To analyze the apoptotic index, TFTe, at concentrations of 25 (Tf1d), 50.89 (Tf2d), and 100 μg/mL (Tf3d) were used to treat bCSCs for 24 h, in a humidified incubator containing 5% CO2, at 37°C. The control group was exposed to dimethyl sulfoxide. Apoptosis was measured by propidium iodide and acridine orange double-staining, and the expression levels of survivin, caspase-9, and caspase-3 were assessed by immunocytochemistry. Statistical Analysis Used: Differences were analyzed by the independent Student's t-test, to compare two groups, and the Kruskal–Wallis test, to compare more than two groups. P < 0.05 was considered statistically significant. Results: TFTe inhibited bCSC proliferation, with an IC50 value of 50.89 μg/mL, and significantly induced apoptosis in bCSCs (P < 0.001). TFTe also significantly decreased the expression levels of survivin in bCSCs (P < 0.001) and increased the expression levels of caspase-9 and caspase-3 (P < 0.001). Conclusions: TFTe can induce apoptosis in bCSCs by decreasing survivin expression levels and increasing the levels of caspase-9 and caspase-3.