Bee venom induces apoptosis through intracellular Ca2+-modulated intrinsic death pathway in human bladder cancer cells

• Published in: International journal of urology 2012-01, Vol.19 (1), p.61-70
• Main Authors: Ip, Siu-Wan, Chu, Yung-Lin, Yu, Chun-Shu, Chen, Po-Yuan, Ho, Heng-Chien, Yang, Jai-Sing, Huang, Hui-Ying, Chueh, Fu-Shin, Lai, Tung-Yuan, Chung, Jing-Gung
• Format: Article
• Language: English
• Subjects: 4',6-Diamidino-2-phenylindole; Apoptosis; Apoptosis - drug effects; Apoptosis - physiology; Apoptosis Inducing Factor - metabolism; Apoptosis-inducing factor; bee venom; Bee Venoms - pharmacology; Calcium (intracellular); Calcium - metabolism; Calcium Signaling - drug effects; Calcium Signaling - physiology; Cancer; Caspase 3 - metabolism; Caspase 8 - metabolism; Caspase 9 - metabolism; Caspase-3; Caspase-9; Cell Line, Tumor; Cell Survival - drug effects; Cell Survival - physiology; Endodeoxyribonucleases - metabolism; Endonuclease; Endoplasmic reticulum; endoplasmic reticulum stress; Endoplasmic Reticulum Stress - drug effects; Endoplasmic Reticulum Stress - physiology; Flow cytometry; human bladder cancer TSGH-8301 cells; Humans; intracellular Ca2+ release; Iron; Lasers; Membrane potential; Membrane Potential, Mitochondrial - drug effects; Membrane Potential, Mitochondrial - physiology; Mitochondria; Nuclei; Signal transduction; Urinary bladder; Urinary Bladder Neoplasms - drug therapy; Urinary Bladder Neoplasms - metabolism; Urinary Bladder Neoplasms - pathology; Venom; Western blotting
• ISSN: 0919-8172; 1442-2042
• DOI: 10.1111/j.1442-2042.2011.02876.x

Objectives:  To focus on bee venom‐induced apoptosis in human bladder cancer TSGH‐8301 cells and to investigate its signaling pathway to ascertain whether intracellular calcium iron (Ca2+) is involved in this effect. Methods:  Bee venom‐induced cytotoxic effects, productions of reactive oxygen species and Ca2+ and the level of mitochondrial membrane potential (ΔΨm) were analyzed by flow cytometry. Apoptosis‐associated proteins were examined by Western blot analysis and confocal laser microscopy. Results:  Bee venom‐induced cell morphological changes and decreased cell viability through the induction of apoptosis in TSGH‐8301 cell were found. Bee venom promoted the protein levels of Bax, caspase‐9, caspase‐3 and endonuclease G. The enhancements of endoplasmic reticulum stress‐related protein levels were shown in bee venom‐provoked apoptosis of TSGH‐8301 cells. Bee venom promoted the activities of caspase‐3, caspase‐8, and caspase‐9, increased Ca2+ release and decreased the level of ΔΨm. Co‐localization of immunofluorescence analysis showed the releases of endonuclease G and apoptosis‐inducing factor trafficking to nuclei for bee venom‐mediated apoptosis. The images revealed evidence of nuclear condensation and formation of apoptotic bodies by 4′,6‐diamidino‐2‐phenylindole staining and DNA gel electrophoresis showed the DNA fragmentation in TSGH‐8301 cells. Conclusions:  Bee venom treatment induces both caspase‐dependent and caspase‐independent apoptotic death through intracellular Ca2+‐modulated intrinsic death pathway in TSGH‐8301 cells.