Assessment of the methylene blue mediated photodynamic therapy on BCL2 and BAX genes expression at mRNA level and apoptosis of head and neck squamous cell carcinoma cell line

Abstract

Aim: This study aimed to assess the effect of photodynamic therapy (PDT) on apoptosis of head and neck squamous cell carcinoma (HNSCC) cells by flow cytometry and evaluating BAX and BCL2 genes expression. Materials and methods: In this in vitro study, human HNSCC cell line (HN5; NCBI. C196) was used and after cell culture, they were divided into four groups: controls (group C), cells irradiated by a diode laser with a wavelength of 660 nm, 150 mW power, and 45 J/cm2 energy density (group L), cells treated by methylene blue (group MB), and cells treated using PDT (group MB plus L). The RNA was then extracted and subjected to quantitative reverse transcription polymerase chain reaction (qRT-PCR) to assess BCL2 and BAX genes expression. Flow cytometry analysis was performed to assess apoptosis. Data were analysed using ANOVA. Results: PDT caused significant down-regulation of BCL2 (p<0.001) and significant overexpression of BAX (p<0.05) and PDT induced apoptosis HNSCC cell line. Changes in expression of these genes were not significant in other groups (p>0.05). Conclusions: Considering the down-regulation of BCL2 and overexpression of BAX after PDT using a 660-nm diode laser and MB with 3.2 µg/mL concentration and flow cytometry results, it is suggested that this modality can be introduced for induction of apoptosis in the HNSCC cell line.