Cisplatin-based chemotherapy often results in the development of chemo-resistance when used to treat bladder cancer (BC), which is difficult to overcome. Recent data indicate that pyruvate kinase M2 (PKM2), a glycolytic enzyme for Warburg effect, is strongly upregulated in BC, and contributes to the cisplatin resistance in BC. However, the underlying mechanisms remain unclear. In this study, we also found that the expression level of PKM2 is also higher in cisplatin resistant BC cells and tumors. Down-regulation of PKM2 by siRNA or inhibition of PKM2 by shikonin re-sensitized the cisplatin resistant T24 cells. Shikonin and cisplatin together exhibit significantly greater killing effects than when used alone. Interestingly, we found shikonin kills the T24 cisplatin resistant cells by inducing necroptosis, as the cell death could not inhibited by apoptosis inhibitor, z-VAD, but compromised by RIP3 inhibitor, GSK872, or RIP3 siRNA. In contrast, shikonin induced apoptosis in T24 parental cells. We further investigate the underlying mechanism, and found that the dysregulation of Bcl-2 family proteins, including Bcl-2, PUMA, Bax, play an important role in deciding that shikonin kills the BC cells by necroptosis or apoptosis. Collectively, our results suggested that inducing necroptosis is an alternative way to overcome the apoptosis resistant in BC therapy, and orchestrating the regulation of Bcl-2, PUMA, and Bax in BC cisplatin resistant cells may improve the therapy effect of cisplatin in BC tumor.

To determine whether treatment of patients with large (>15 mm) impacted upper ureteral stones depended on stone location, we prospectively evaluated the therapeutic outcomes, complications, safety, and effectiveness of percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotomy (URSL) in patients with stones higher and lower than the upper border of the fourth lumbar vertebra. Of the 174 patients analyzed, 83 (47.7%) underwent PCNL and 91 (52.3%) underwent URSL; all patients were followed up 1 month later and every 6 months for 18 months. Mean operation time (108.76±19.36 vs. 63.56±16.38 minutes, p<0.05) and postoperative hospital stay (2.49±1.23 vs. 5.36±1.98 days, p<0.05) were significantly longer in the PCNL than in the URSL group. The overall stone-free rates after 1 month were 96.4% and 75.8%, respectively, differing significantly for stones higher (97.8% vs. 57.5%, p<0.05) but not lower (94.7% vs. 90.2%) than the upper border of the fourth lumbar vertebra. The stone-retropulsion rate of URSL differed significantly for stones higher and lower than the upper border of the 4th lumbar vertebra (47.5% vs. 9.8%, p<0.05). Postprocedural complication rates were comparable in the URSL and PCNL groups, although the rate of auxiliary or salvage procedures was higher in the URSL group. The efficiency quotients (EQ) for PCNL and URSL were 0.93 and 0.59, respectively, with EQs in the URSL group differing significantly for stones higher and lower than the upper border of the fourth lumbar vertebra (0.40 vs. 0.82, p<0.05). Our findings indicate that treatment of impacted upper ureteral stones is dependent on stone location relative to the upper border of the fourth lumbar vertebra. URSL is unsuitable for stones at a higher location, whereas URSL and PCNL were equally effective for stones at a lower location.

1. Deletion of phenylalanine at position 508 (DeltaF508) of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is the most common mutation causing cystic fibrosis (CF). Effective pharmacological therapy of CF caused by the DeltaF508-CFTR mutation requires the rescue of both intracellular processing and channel gating defects. 2. We identified a class of natural coumarin compounds that can correct the defective DeltaF508-CFTR chloride channel gating by screening a collection of 386 single natural compounds from Chinese medicinal herbs. Screening was performed with an iodide influx assay in Fischer rat thyroid epithelial cells coexpressing DeltaF508-CFTR and an iodide-sensitive fluorescent indicator (YFP-H148Q/I152L). 3. Dose-dependent potentiation of defective DeltaF508-CFTR chloride channel gating by five coumarin compounds was demonstrated by the fluorescent iodide influx assay and confirmed by an Ussing chamber short-circuit current assay. Activation was fully abolished by the specific CFTR inhibitor CFTR(inh)-172. Two potent compounds, namely imperatorin and osthole, have activation K(d) values of approximately 10 micromol/L, as determined by the short-circuit current assay. The active coumarin compounds do not elevate intracellular cAMP levels. Activation of DeltaF508-CFTR by the coumarin compounds requires cAMP agonist, suggesting direct interaction with the mutant CFTR molecule. Kinetics analysis indicated rapid activation of DeltaF508-CFTR by the coumarin compounds, with half-maximal activation of < 5 min. The activating effect was fully reversed for all five active compounds 45 min after washout. 4. In conclusion, the natural coumarin DeltaF508-CFTR activators may represent a new class of natural lead compounds for the development of pharmacological therapies for CF caused by the DeltaF508 mutation.