The Mechanism Of Dihydroartemisinin For Cutaneous Squamous Cell Carcinoma

Background and purposeCutaneous squamous cell carcinoma(cSCC)is a kind of skin cancer derived from keratinocytes.In most cases,unmetastatic cSCC cases can be cured by surgical resection.However,for metastatic,recurrent and unresectable cases of cSCC,current treatment methods are poor,and new treatment strategies and drugs are still needed.Dihydroartemisinin(DHA),a derivative of artemisinin,is an important drug for the treatment of malaria.In recent years,the anti-tumor effect of DHA has been confirmed in a variety of tumor models,and its anticancer mechanisms are diverse,including promoting apoptosis,activating endoplasmic reticulum stress,accelerating oxidative damage induced by Fe2+ and promoting autophagy.At present,whether DHA can be used to treat cSCC and the relevant mechanism of action are not completely clear.Existing studies have shown that autophagy,absent in melanoma 2(AIM2)inflammasome pathway and nuclear factor-κB(NF-κB)/hypoxia-inducible factor-la(HIF-la)/vascular endothelial growth factor(VEGF)pathway play an important role in the occurrence and development of cSCC.The purpose of this study was to verify the therapeutic effect of DHA on cSCC and explore the therapeutic mechanism.Methods and resultsIn this study,cSCC A431 cells were selected as the research object.We used DHA to stimulate A431 cells and proved that DHA inhibited the proliferation of A431 cells in a time-and dose-dependent manner by observation and cell counting kit-8 assay.Then we observed the effect of DHA on colony formation of A431 cells by colony formation assay,and the results showed that the colony formation rate of A431 cells treated with DHA was significantly decreased.We conducted the cell invasion assay and the wound healing assay on A431 cells respectively.In the cell invasion assay,the number of invasive cells through Matrigel glue in the DHA group was significantly less than that in the control group.In the wound healing assay,the cell migration rate of the DHA group was significantly lower than that of the control group.Subsequently,we detected autophagy in A431 cells and found that DHA promoted autophagy in A431 cells.Furthermore,we detected the mammalian target of rapamycin(mTOR)in the upstream of autophagy and found that DHA could inhibit the activation of mTOR.We speculated that DHA might promote autophagy in A431 cells by inhibiting mTOR.In order to further explore the therapeutic mechanism of DHA on cSCC,we detected the expression of AIM2 inflammasome pathway and NF-κB/HIF-1α/VEGF pathway.It was found that DHA inhibited the activation of AIM2 inflammasome pathway and NF-κB/HIF-1α/VEGF pathway in A431 cells.In order to explore the relationship between DHA-promoted autophagy and the inhibition of AIM2 inflammasome pathway and NF-κB/HIF-1α/VEGF pathway,we used autophagy inhibitors and promoters to co-stimulate A431 cells with DHA and found that DHA inhibited the activation of AIM2 inflammasome pathway and NF-κB/HIF-1α/VEGF pathway by promoting autophagy.We believed that DHA might play its therapeutic role in cSCC through the above mechanism.ConclusionsThis study proved that DHA could inhibit the proliferation,invasion and migration of cSCC A431 cells.DHA inhibited the activation of AIM2 inflammasome pathway and NF-κB/HIF-1α/VEGF pathway by promoting autophagy in A431 cells,thus playing a therapeutic role.This study explored the effect of DHA on AIM2 inflammasome pathway and NF-κB/HIF-1α/VEGF pathway in A431 cells from the perspective of autophagy,providing new theoretical support for the application of DHA in the clinical treatment of cSCC.