RÉSUMÉ
Ginsenoside Rg5 is a rare ginsenoside showing promising tumor-suppressive effects.This study aimed to explore its radio-sensitizing effects and the underlying mechanisms.Human lung adenocarcinoma cell lines A549 and Calu-3 were used for in vitro and in vivo analysis.Bioinformatic molecular docking prediction and following validation by surface plasmon resonance(SPR)technology,cellular thermal shift assay(CETSA),and isothermal titration calorimetry(ITC)were conducted to explore the binding between ginsenoside Rg5 and 90 kD heat shock protein alpha(HSP90α).The effects of ginsenoside Rg5 on HSP90-cell division cycle 37(CDC37)interaction,the client protein stability,and the downstream regulations were further explored.Results showed that ginsenoside Rg5 could induce cell-cycle arrest at the G1 phase and enhance irradiation-induced cell apoptosis.It could bind to HSP90α with a high affinity,but the affinity was drastically decreased by HSP90α Y61A mutation.Co-immunoprecipitation(Co-IP)and ITC assays confirmed that ginsenoside Rg5 disrupts the HSP90-CDC37 interaction in a dose-dependent manner.It reduced irradiation-induced upre-gulation of the HSP90-CDC37 client proteins,including SRC,CDK4,RAF1,and ULK1 in A549 cell-derived xenograft(CDX)tumors.Ginsenoside Rg5 or MRT67307(an IKKe/TBK1 inhibitor)pretreatment suppressed irradiation-induced elevation of the LC3-Ⅱ/β ratio and restored irradiation-induced downregulation of p62 expression.In A549 CDX tumors,ginsenoside Rg5 treatment suppressed LC3 expression and enhanced irradiation-induced DNA damage.In conclusion,ginsenoside Rg5 may be a potential radiosensitizer for lung adenocarcinoma.It interacts with HSP90α and reduces the binding between HSP90 and CDC37,thereby increasing the ubiquitin-mediated proteasomal degradation of the HSP90-CDC37 client proteins.
RÉSUMÉ
The treatment of lower extremity chronic refractory ulcers requires a long time but with poor prognosis. Thus, many patients end up with amputations. The treatment of lower extremity chronic and recalcitrant ulcers and limb salvage has been a challenge worldwide. The Ilizarov technique based on the law of "tension-stress" brings a new hope in treating lower limb chronic and recalcitrant ulcers. The Ilizarov technique and distraction osteogenesis not only induce bone formation but also lead to angiogenesis and improved microcirculation. The Ilizarov technique consists of longitudinal distraction of long bone and tibia trans-verse transport (TTT) (proximal tibial corticotomy followed by transverse distraction). These two techniques have their own advantages and disadvantages with different indications in clinical application. Longitudinal distraction of long bone is mainly used for bone formation, such as large bone defects, osteonecrosis or bone infection (with or without soft tissue loss or ulcers). Because of only a partial osteotomy in TTT, the trauma is minor and their effects on limb instability are limited. Moreover, the procedure is simple with only a few minor complications. Thus, it is ideal in treating lower limb ischemic ulcers, such as diabetic foot ulcers, thromboangiitis obliterans (Buerger's disease), ulcers caused by atherosclerotic occlusion, arterial or venous ulcers, and trauma wounds. Several studies reported that TTT achieved high healing and limb salvage rates in treating severe diabetic foot ulcer. However, TTT could achieve lower recurrent rate. Thus, it is the most successful application in treatment of chronic ulcers. TTT also improves healing and limb salvage in treatment of thromboangiitis obliterans. However, the overall effects are limited than those in treating diabetic foot ulcer. For lower limb atherosclerosis occlusion, TTT induces regeneration of microvessles and consequently leads to ulcer healing. The effects are better than other conventional treatments. A combination therapy with vascularization is emphasized to attain the optimal long-term effects. The effects of TTT on lower limb recalcitrant ulcers still need to be validated in randomized control trial with larger sample size. Further, the mechanism of treatment needs to be explored by pilot studies which could show that this may be related to the formation of pro-angiogenetic factors and a rebalance of the inflammatory microenvironment during TTT.