Aloe-Emodin-Mediated Photodynamic Therapy Induces Apoptosis in Basal Cell Carcinoma Cells via Activation of ERK/JNK Signaling Pathway

Abstract

Basal cell carcinoma (BCC) is the most prevalent epidermal cancerous neoplasm. Previous studies have reported the noninvasive, cost-effective, and localized photodynamic therapy (PDT) approach to BCC treatment. This study investigated the photodynamic effects of aloe-emodin (AE), a natural anthraquinone photosensitizer (PS), on proliferation and apoptosis of BCC TE 354.T cell line. To evaluate the effects of AE-mediated PDT, we used various concentrations of AE (0, 2.5, 5, and 10 μM) and white light energy (0, 12, 24, and 36 J/cm2). CCK-8 assay was used to analyse cell viability following AE-mediated PDT. The cell death rate and reactive oxygen species (ROS) were assessed by flow cytometry. Western blotting was used to determine the effects of AE-mediated PDT on the apoptotic proteins, Akt, and MAPK pathways. AE-mediated PDT inhibited tumorigenic cell proliferation, consequently enhancing apoptosis in AE and PDT concentration and dose-dependent manner, respectively. Significantly increased TE 354.T cell apoptosis and intracellular ROS production were both observed after AE-mediated PDT. Following the AE-mediated PDT, cytochrome and antitumor p53 were elevated; however expression of Bcl-2 was significantly decreased. Significant caspase 3 elevation post-AE-mediated PDT suggested intrinsically driven apoptosis. Additionally, AE-mediated PDT significantly suppressed NF-κB, Akt, and ERK pathways while JNK expression was significantly increased. AE-mediated PDT induced TE 354.T cell apoptosis through the intracellular generation of ROS. Akt, ERK, and JNK all play various roles in ensuring successful TE 354.T tumor cell apoptosis.