lncRNA TINCR participates in ALA‐PDT‐induced apoptosis and autophagy in cutaneous squamous cell carcinoma

: This study aims to investigate whether terminal differentiation-induced ncRNA (TINCR) has an effect on apoptosis and autophagy induced by ALA-PDT in cutaneous squamous cell carcinoma (CSCC). A431 cells were treated with 5-aminolevulinic acid (ALA) solution at different concentrations and for different duration time. A431 cell viability was detected by Cell Counting Kit-8 (CCK-8) assay, relative TINCR messenger RNA expression was detected by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). A431 cell apoptosis was examined by flow cytometry. Relative apoptosis/autophagy-related protein expression was analyzed by Western blot analysis. The effect of TINCR on cell autophagy was detected by RFP-LC3 immunofluorescence assay. Reactive oxygen species concentration was detected by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe. Relative expressions of ERK1/2 and specificity protein 3 (Sp3) in A43 cells were detected by Western blot analysis and qRT-PCR. Sp3 binding sites were analyzed by ChIP-qPCR. The relative transcription activity was measured with luciferase reporter assay. ALA-PDT treatment at 3.2 mmol/L for 120 minutes significantly promoted TINCR expression in CSCC A431 cells, and TINCR promoted ALA-PDT-induced apoptosis and cell autophagy. Furthermore, ALA-PDT promoted TINCR expression through ERK1/2-SP3 pathway. Sp3 promoted TINCR transcription by binding TINCR promoters. Our data indicated that TINCR involves in ALA-PDT-induced apoptosis and autophagy in CSCC.