Anti-Leukemic Effect of Malachite Green-Mediated Photodynamic Therapy by Inducing ER Stress in HL-60 Cells

Abstract

Aim: Our objective is to explore the relationship between the anti-leukemic impact of malachite green-mediated photodynamic therapy (PDT) and the induction of endoplasmic reticulum (ER) stress in acute promyelocytic leukemia cells (HL-60). Material and Method: For one hour the cells were incubated with different concentrations (3.125, 1.56, 0.78, 0.39, 0.195, 0.0975, 0.04875 μM) of malachite green and then were exposed to 0.47 mW/cm2 irradiance and 0.84 J/cm2 fluence for 30 minutes. Also, HL-60 cells were exposed to PDT with light only and both in the presence or absence of malachite green. MTT assay was used to determine cell viability, and immunocytochemical staining was used to detect the expression of ER stress markers Protein Kinase R-like ER Kinase (PERK) and Glucose-regulated protein 78 (GRP78). Results: The cell viability of the treatment group (combination of malachite green and light) was significantly decreased compared to the malachite green, control group, and light control. Moreover, immunocytochemical staining scores showed that PERK and GRP78 were significantly upregulated in the treatment group compared with other groups. Conclusion: Our results indicate that ER stress may contribute to the cytotoxicity occurring in HL-60 cancer cells after malachite green-mediated PDT. Future studies will be crucial in shedding light on the molecular mechanisms underlying ER stress that may occur after PDT. These findings lay the foundation for further investigations in this area.