Blue light-induced apoptosis of human promyelocytic leukemia cells via the mitochondrial-mediated signaling pathway.

Abstract

Acute promyelocytic leukemia is frequently associated with dizziness, fever, nausea, hematochezia and anemia. Blue light, or light with wavelengths of 400-480 nm, transmits high levels of energy. The aim of the present study was to determine the pro-apoptotic effects of blue light (wavelength, 456 nm; radiation power, 0.25 mW/cm2) and the underlying mechanisms in a human promyelocytic leukemia cell line (HL60). Blue light reduced the viability and enhanced the mortality of HL60 cells in a time-dependent manner. Exposure to blue light for 24 h caused depolarization of the mitochondrial membrane potential and the overproduction of reactive oxygen species in HL60 cells. In a nude mouse model, 9-day exposure to blue light markedly suppressed the growth of HL60-xenografted tumors; however, it had no effect on hepatic and renal tissues. In addition, blue light abrogated the expression of B-cell lymphoma (Bcl)-2 and Bcl extra-long, while enhancing the levels of Bcl-2-associated X protein, cytochrome c, and cleaved caspases-3 and -9 in tumor tissues. The results suggested that the pro-apoptotic effects of blue light in human promyelocytic leukemia cells may be associated with the mitochondrial apoptosis signaling pathway.

• Authors: Jianjian Zhuang, Yange Liu, Qingxia Yuan, Junsong Liu, Yan Liu, Hongdong Li, Di Wang
• Journal: Oncology letters (Oncol Lett) Vol. 15 Issue 5 Pg. 6291-6296 (May 2018) ISSN: 1792-1074 [Print] Greece
• PMID: 29731847 (Publication Type: Journal Article)