Metformin exerts an antitumor effect by inhibiting bladder cancer cell migration and growth, and promoting apoptosis through the PI3K/AKT/mTOR pathway.

BACKGROUND: To observe and explore the effect of metformin on the migration and proliferation of bladder cancer T24 and 5637 cells in vitro. METHODS: Bladder cancer T24 and 5637 cell lines were cultured in vitro, and were divided into group A (blank control group) and group B (metformin group: 5, 10, 15, and 20 mmol/L); both groups were plated on 6-well plates at the same time. Culture in 24-well plates was used for wound healing assays and in 96-well plates for Transwell migration and invasion, and Cell Counting Kit-8 proliferation experiments. We observed and detected the cell migration and proliferation ability of each group at 48 h, and calculated the cell migration area and survival rate. Flow cytometry was used to detect cell apoptosis in the groups. The apoptosis-related proteins, cleaved-caspase 3, cleaved-PARP, and the PI3K/AKT/mTOR signaling pathway member proteins PI3K, phosphorylated (p)-PI3K, AKT, p-AKT, mTOR, and p-mTOR were detected using western blotting. RESULTS: After 48 h of treatment with different concentrations of metformin, the cell migration and proliferation capabilities were significantly lower than those in the blank control group. The proliferation and migration abilities of T24 and 5637 cells decreased in a metformin concentration-dependent manner (P < 0.05). The apoptosis rate under different concentrations of metformin, as detected by flow cytometry, showed a significantly higher rate in the metformin group than in the control group (P < 0.05). Compared with that in the control group, the level of cleaved-caspase 3 and cleaved-PARP protein in the metformin group was increased in each treatment group, and the levels of p-mTOR, p-AKT, and p-PI3K decreased significantly compared with those in the control group (P < 0.05). CONCLUSION: Metformin inhibited bladder cancer T24 and 5637 cell migration and proliferation, and induced their apoptosis. The mechanism might involve inhibition of the activation of the PI3K/AKT/mTOR signaling pathway.

Effectiveness of sharp recanalization of superior vena cava-right atrium junction occlusion.

BACKGROUND: Conventional recanalization techniques may fail in patients with completely occluded superior vena cava (SVC). AIM: To analyze the effectiveness and complications of sharp recanalization for completely occluded SVC. METHODS: This was a retrospective study of patients that underwent puncture and recanalization of the SVC between January 2016 and December 2017 at our hospital. Sharp recanalization was performed using the RUPS-100 system. The patients were followed for 12 mo. The main outcomes were the patency rate of SVC and arteriovenous fistula flow during dialysis. RESULTS: The procedure was successful in all 14 patients (100%). Blood pressure in the distal SVC decreased in all 14 cases (100%) from 26.4 ± 2.7 cmH2O to 14.7 ± 1.3 cmH2O (P < 0.05). The first patency rates of the SVC at 24 h and at 3, 6, 9 and 12 mo after sharp recanalization were 100%, 92.9%, 85.7%, 78.6% and 71.4%, respectively. There were two (14.3%) severe, one (7.1%) moderate and one (7.1%) minor complication. The severe complications included one case of pericardial tamponade and one case of hemothorax. CONCLUSION: The results suggest that sharp recanalization can be an additional tool to extend or renew the use of an occluded upper extremity access for hemodialysis. This could be of use in patients with long-term maintenance hemodialysis in whom the maintenance of central venous access is often a challenge.