Inhibition of ROS-NF-κB-dependent autophagy enhances Hypocrellin A united LED red light-induced apoptosis in squamous carcinoma A431 cells

Cutaneous squamous cell carcinoma (cSCC) is a type of malignant skin tumor derived from epidermal Malpighian cells. Photodynamic therapy is regarded as a crucial method in oncology. Hypocrellin A (HA), an efficient natural photosensitizer, has been reported to exert excellent light induced antiviral, antimicrobial and anticancer activity through mediating multiple signaling pathways. The purpose of the present study is to examine the effects of HA united red light irradiation on human squamous carcinoma A431 cells and further reveal the underlying regulatory mechanisms. The results showed that synergistic treatment of HA and red light irradiation inhibited cell proliferation and induced cell apoptosis and autophagy. Moreover, HA united red light irradiation caused a significant accumulation of reactive oxygen species (ROS), and induced the activation of c-Jun NH 2 terminal kinases (JNICs) which was inhibited by the antioxidant N-Acetyl-cysteine (NAC). Furthermore, HA united red light irradiation activated the nuclear factor-kappa B (NF-kappa B) pathway, and inhibition of NF-kappa B activity exacerbated HA united red light irradiation-induced apoptosis but suppressed cell autophagy. In addition, the inhibition of autophagy promoted HA united red light irradiation-induced apoptosis and facilitated the NF-kappa B activity. Over all, our results revealed that HA united red light irradiation could inhibit A431 cell proliferation by inducing apoptosis and autophagy via the activation of the ROS mediated JNK and NF-kappa B pathways, providing prospective for HA as a potential therapeutic for the treatment of cSCC.