Gambogenic acid mediated apoptosis through the mitochondrial oxidative stress and inactivation of Akt signaling pathway in human nasopharyngeal carcinoma CNE-1 cells

In the present study, Gambogenic acid exhibits potential anti-tumor activity in several cancer cell lines. However, Gambogenic acid-induced apoptosis mechanism is not well understood. Here, we report that Gambogenic acid was capable to induce CNE-1 cells apoptosis and caused mitochondrial and endoplasmic reticulum injury, analyzed via transmission electron microscopy and acridine orange/ethidium bromide (AO/EB) double staining. To quantitatively analyze apoptosis, through the propidium iodide (PI)/Annexin V-FITC double staining to detect cell apoptosis, PI staining of the cell cycle distribution. To further explore the potential mechanism of Gambogenic acid mediated apoptosis in CNE-1 cells, we also examined mitochondrial oxidative stress in the levels of reactive oxygen species, the release of cytochrome c, intracellular Ca2+ concentration and mitochondrial membrane potential by flow cytometry. Moreover, Gambogenic acid could result in a time and concentration-dependent decrease in Phospho-Akt expression, basal expression levels of Akt change was not obvious, In addition, we detected Bcl-2 family including Bcl-2, Bax and Bad expression in mRNA level. This resulted in a decrease of Bcl-2 and Bad increased in CNE-1 cells after Gambogenic acid treatment. Overall, our results indicated that Gambogenic acid mediated apoptosis through inactivation of Akt, accompanied with mitochondrial oxidative stress and cross-talk with Bcl-2 family in the process of apoptosis.