Cantharidin Induced Oral Squamous Cell Carcinoma Cell Apoptosis via the JNK-Regulated Mitochondria and Endoplasmic Reticulum Stress-Related Signaling Pathways

• Published in: PloS one 2016-12, Vol.11 (12), p.e0168095
• Main Authors: Su, Chin-Chuan, Lee, Kuan-I, Chen, Mu-Kuan, Kuo, Chun-Ying, Tang, Chih-Hsin, Liu, Shing Hwa
• Format: Article
• Language: English
• Subjects: Analysis; Antineoplastic Agents - therapeutic use; Apoptosis; Apoptosis - drug effects; Apoptosis - physiology; Apoptosis-inducing factor; BAK protein; BAX protein; Bcl-2 protein; Beetles; Biology and Life Sciences; Bladder cancer; Blistering; Blotting, Western; Breast cancer; Cancer; Cancer therapies; Cantharidin - therapeutic use; Carcinoma, Squamous Cell - drug therapy; Carcinoma, Squamous Cell - physiopathology; Care and treatment; Caspase; Caspase-12; Caspase-3; Caspase-7; Caspase-9; Cell culture; Cell Line, Tumor; Chemotherapy; Colorectal cancer; Cytochrome; Cytochrome c; Development and progression; Endoplasmic reticulum; Endoplasmic Reticulum - physiology; Extracellular signal-regulated kinase; Head; Head & neck cancer; Head and neck cancer; Health aspects; Hospitals; Humans; In Vitro Techniques; JNK protein; Kinases; Lung cancer; Lymph nodes; MAP Kinase Signaling System - physiology; Medical prognosis; Medicine; Medicine and Health Sciences; Membrane potential; Membrane Potential, Mitochondrial - drug effects; Metastases; Mitochondria; Mitochondria - drug effects; Mitochondria - physiology; Mouth Neoplasms - drug therapy; Mouth Neoplasms - physiopathology; Oral cancer; Oral squamous cell carcinoma; Otolaryngology; Pancreatic cancer; Phosphorylation; Poisoning; Protein kinases; Proteins; Real-Time Polymerase Chain Reaction; Research and Analysis Methods; Signal transduction; Signal Transduction - physiology; Signaling; Squamous cell carcinoma; Stress; Stresses; Studies; Surgery; Tongue; Tongue Neoplasms - drug therapy; Tongue Neoplasms - physiopathology; Toxicology
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0168095

Oral cancer is a subtype of head and neck cancer which represents 2.65% of all human malignancies. Most of oral cancer is histopathologically diagnosed as oral squamous cell carcinoma (OSCC). OSCC is characterized by a high degree of local invasion and a high rate of metastasis to the cervical lymph nodes. How to prevention and treatment of OSCC is important and imperative. Here, we investigated the therapeutic effect and molecular mechanism of cantharidin, an active compound isolated from blister beetles, on OSCC in vitro. Results showed that cantharidin significantly decreased cell viability in human tongue squamous carcinoma-derived SAS, CAL-27, and SCC-4 cell lines. The further mechanistic studies were carried out in SAS cells. Cantharidin also significantly increased apoptosis-related signals, including caspase-9, caspase-7 and caspase-3 proteins. Besides, cantharidin decreased mitochondrial transmembrane potential (MMP) and induced cytochrome c and apoptosis inducing factor (AIF) release. Cantharidin also increased Bax, Bid, and Bak protein expressions and decreased Bcl-2 protein expression. Cantharidin could also increase the endoplasmic reticulum (ER) stress signals, including the expressions of phosphorylated eIF-2α and CHOP, but not Grp78 and Grp94. Furthermore, cantharidin reduced pro-caspase-12 protein expression. In signals of mitogen-activated protein kinases, cantharidin increased the phosphorylation of JNK, but not ERK and p38. Transfection of shRNA-JNK to OSCC cells effectively reversed the cantharidin-induced cell apoptotic signals, including the mitochondrial and ER stress-related signaling molecules. Taken together, these findings suggest that cantharidin induces apoptosis in OSCC cells via the JNK-regulated mitochondria and ER stress-related signaling pathways.