[ ABSTRACT] AIM:To explore the role of SHARPIN in regulation of Rip1 in castration-resistant prostate cancer LNCaP-AI cells.METHODS:The LNCaP-AI cells were treated with TNF-α+Z-VAD ( an inhibitor of pan-caspase) to activate necroptosis, which were compared to the cells treated with TNF-α+Z-VAD+Nec-1 ( an inhibitor of Rip1 ) .A blank group and a TNF-α-treated group were set up as controls.The cell viability in each group was measured by MTS as-say.In addition, SHARPIN was knocked down by siRNA, and the inhibitory efficiency was evaluated by RT-qPCR.The expression of Rip1 at mRNA and protein levels after knocking down SHARPIN was determined by RT-qPCR and Western blot to explore the underlying mechanism of regulatory network of necroptosis in prostate cancer.RESULTS: Compared with blank control group and TNF-α-treated group, the viability of LNCaP-AI cells treated with TNF-α+Z-VAD decreased by 28%(P<0.05).After treated with TNF-α+Z-VAD+Nec-1, the LNCaP-AI cells showed no significant difference in the viability compared with blank control and TNF-α-treated groups.Taken together, necroptosis may be an important way of cell death in LNCaP-AI cells.Besides, the expression of Rip1 at protein level was up-regulated following the inhibition of SHARPIN using siRNA, indicating that down-regulation of SHARPIN enhanced necroptosis via activating Rip1 in
LNCaP-AI cells.CONCLUSION:Necroptosis is an important way of cell death .Inhibition of oncogenic factor SHARPIN enhances necroptosis via activating Rip1 in LNCaP-AI cells.

Objective:To compare the clinical effects on new bone formation and foot-ankle function between proximal tibial bone transport and distal tibial bone transport in the treatment of massive bone defects after tibial osteomyelitis debridement.Methods:From July 2012 to July 2017, 42 patients with chronic tibial osteomyelitis received bone transport surgery at Department of Orthopaedics, Nanfang Hospital.According to the Cierny-Mader classification for chronic osteomyelitis, all of them belonged to diffusive tibial osteomyelitis (type IV).Of them, 32 were treated by proximal tibial bone transport after tibial osteomyelitis debridement.In the proximal group, there were 27 males and 5 females, aged from 17 to 65 years and involving 20 left and 12 right sides. The other 10 cases received distal tibial bone transport. In the distal group, all of them were male, aged from 25 to 63 years and involving 6 left and 4 right sides. The 2 groups were compared in terms of external fixation index (EFI) and American Orthopaedic Foot & Ankle Society(AOFAS) Ankle and Hindfoot Scale.Results:There were no significant differences between the 2 groups in the preoperative general data such as gender, age or osteomyelitis site, indicating the 2 groups were comparable ( P>0.05). Both groups obtained complete follow-up. The proximal group was followed up for 590.1 d ± 287.3 d and the distal group for 615.6 d ± 130.6 d, showing no significant difference between groups ( P>0.05). In the proximal group 2 cases developed talipes equinovalgus after bone transport while in the distal group 3 cases did, and surgical intervention was needed for them. Surgical intervention was also carried out for16 cases of non-union at the docking site in the proximal group and for 2 ones in the distal group. The EFI was 76.2 d/cm±50.0 d/cm for the proximal group and 84.3 d/cm ± 59.9 d/cm for the distal group, showing no significant difference between groups ( P>0.05). The AOFAS scores were 81.4±10.1 for the proximal group and 60.0±5.9 for the distal group, showing a significant difference ( P<0.05). Conclusion:In the treatment of massive bone defects after tibial osteomyelitis debridement, no significant difference has been observed in the effect on bone formation between proximal tibial bone transport and distal tibial bone transport, but the former transport may have a less adverse effect on foot-ankle function.