Effects of 630 nm laser on apoptosis, metastasis, invasion and epithelial-to-mesenchymal transition of human lung squamous cell carcinoma H520 cells mediated by hematoporphyrin derivatives.

Photodynamic therapy (PDT) has significant advantages in the treatment of malignant lung tumors. The research on the mechanism of PDT mediated by hematoporphyrin derivatives (HPD) and its cytotoxic effects on lung cancer cells has primarily focused on lung adenocarcinoma cells. However, the impact of HPD-PDT on lung squamous cell carcinoma has not been thoroughly studied. This study aimed to investigate the effects of 630 nm laser on apoptosis, metastasis, invasion, and epithelial-mesenchymal transition (EMT) in human lung squamous cell carcinoma H520 cells mediated by HPD. H520 cells were divided into four groups: control group, photosensitizer group, irradiation group, and HPD-PDT group. Cell proliferation was assessed using CCK8 assay; cell apoptosis was detected by Hoechst 33258 staining and flow cytometry; cell migration and invasion abilities were evaluated using wound-healing and invasion assays; and protein and mRNA expressions were analyzed by Western blot and reverse transcription-polymerase chain reaction (RT-PCR) respectively. Results showed that HPD-PDT significantly inhibited cell proliferation, promoted apoptosis (P < 0.05), suppressed cell migration and invasion (P < 0.05), decreased Bcl-2 mRNA expression, and increased Bax and Caspase-9 mRNA expression(P < 0.05). Western blotting analysis indicated increased expression of Bax, Caspase-9, and E-cadherin, and decreased expression of Bcl-2, N-cadherin, and Vimentin (P < 0.05). In conclusion, 630 nm laser mediated by HPD promoted cell apoptosis via upregulation of Bax and caspase-9, and downregulation of Bcl-2, and inhibited cell migration and invasion by regulating EMT in H520 cells.