The Optimal Temperature Of Killing Cutaneous Squamous Cell Carcinoma Cells And Promoting Release Of DAMPs By In Situ Photoimmunotherapy

BackgroundCutaneous squamous cell carcinoma is the second most common human non-melanoma skin cancer, and is becoming increasingly common around the world. But it is very difficult to treat this disease. In situ photoimmunotherapy is a new cancer therapy combined with photothermal therapy and immunoadjuvant. An important aspect of photothermal interaction through laser ablation is that a thermal gradient is generated inside the tumor tissue, direct damaging or activating tumor cells, and promoting the release of DAMPs to induce cellular immunity. However, the effect on the expression of DAMPs by temperature is still not clear, during the treatment of UV-induced SKH-1 hairless mice cutaneous squamous cell carcinoma by in situ photoimmunotherapy.Cutaneous squamous cell carcinoma as the object of this study, preliminary observing the curative effect of in situ photoimmunotherapy on it to expand in situ photoimmunotherapy clinical indications, and studying the effects of temperature on the expression of squamous cell carcinoma cell line DAMPs to provide a theoretical basis for the optimization of in situ photoimmunotherapy.MethodsIn vivo, observing the changes of tumor in each group, after the UV-induced cutaneous squamous cell carcinoma SKH-1 hairless mice were randomly divided into four groups: control group, laser group, imiquimod group and photoimmunotherapy group. In vitro, by cell culture technology, detecting A431 cells proliferation and the expression of DAMPs after different temperature treatment, respectively by CCK8 assay, flow cytometry, Western blot and ELISA.ResultsThe in vivo experiments showed that in situ photoimmunotherapy could be an effective treatment for mice skin squamous cell carcinoma. The in vitro experiments showed that low temperature (37℃,40℃) had no obvious inhibitory effect on A431 cell growth and on the expression of HSP70, HSP90 and HMGB1; moderate temperature (45℃,50 ℃) had obvious inhibitory effect on A431 cell growth and could stimulate the large release of HSP70, HSP90 and HMGB1, but 45℃ also promoted the expression of intracellular HSP70, HSP90 and HMGB1; high temperature (55℃,60℃) directly leaded to cell death and the intracellular and extracellular expression of HSP70, HSP90 and HMGB1was significantly reduced.ConclusionIn situ photoimmunotherapy was an effective therapy for cutaneous squamous cell carcinoma.50℃10 min, having the strongest ability killing cutaneous squamous cell carcinoma cells and stimulating cutaneous squamous cell carcinoma cells to release DAMPs, may be the optimal temperature.