Apoptotic Effects of Cryptotanshinone on Human Esophageal Carcinoma HCE-4 Cells and Related Mechanism

Abstract

Objective To explore the effects and pharmacological mechanism of cryptotanshinone (CT) on human esophageal carcinoma HCE-4 cells. Methods MTT assay was performed to determine the cytotoxic effects of CT on HCE-4 and TE-2 cells. The morphological alterations of HCE-4 cells were demonstrated by inverted microscope. Annexin V-FITC/PI double staining and flow cytometry were used to detect the apoptotic effect and reactive oxygen species (ROS) levels of CT in HCE-4 cells. Western blot was performed to investigate the expression levels of apoptotic and upstream signaling pathway-related proteins. Results MTT assay results suggested that CT significantly inhibited the viabilities of esophageal carcinoma HCE-4 and TE-2 cells in a dose-dependent manner. The apoptotic morphology of HCE-4 cells was found under the inverted microscope, such as cell shrinkage, becoming round and the number of suspended cells were increased. Annexin V-FITC/PI double staining and flow cytometry results showed that CT could induce the apoptosis of HCE-4 cells and increase the accumulation of intracellular ROS. Pre-treatment with N-acetyl-L-cysteine (NAC), an ROS scavenger, inhibited the CT-induced apoptosis. Western blot results showed that CT increased the protein expression levels of p-JNK, p-p38, Bad, Caspase-3 and PARP, and also decreased the protein expression levels of p-ERK, p-AKT and Bcl-2. Conclusion Cryptotanshinone inhibits the proliferation and induces the apoptosis of HCE-4 cells via ROS-mediated regulation of MAPK and AKT signaling pathways.

Keywords

• cryptotanshinone
• esophageal carcinoma
• hce-4 cells
• mapk signal pathway
• akt signal pathway
• reactive oxygen species