Drug-induced AF: Arrhythmogenic Mechanisms and Management Strategies.

AF is a prevalent condition that is associated with various modifiable and unmodifiable risk factors. Drug-induced AF, despite being commonly under-recognised, can be relatively easy to manage. Numerous cardiovascular and non-cardiovascular agents, including catecholaminergic agents, adenosine, anti-tumour agents and others, have been reported to induce AF. However, the mechanisms underlying drug-induced AF are diverse and not fully understood. The complexity of clinical scenarios and insufficient knowledge regarding drug-induced AF have rendered the management of this condition complicated, and current treatment guidelines follow those for other types of AF. Here, we present a review of the epidemiology of drug-induced AF and highlight a range of drugs that can induce or exacerbate AF, along with their molecular and electrophysiological mechanisms. Given the inadequate evidence and lack of attention, further research is crucial to underscore the clinical significance of drug-induced AF, clarify the underlying mechanisms and develop effective treatment strategies for the condition.

1,4-Disubstituted Piperazin-2-Ones as Selective Late Sodium Current Inhibitors with QT Interval Shortening Properties in Isolated Rabbit Hearts.

Late sodium current (INa) inhibitors are a new subclass of antiarrhythmic agents. To overcome the drawbacks, e.g., low efficacy and inhibition effect on K+ current, of the FDA-approved late INa inhibitor ranolazine, chain amide 6a-6q, 1,4-disubstituted piperazin-2-ones 7a-7s, and their derivatives 8a-8n were successively designed, synthesized, and evaluated in vitro on the NaV1.5-transfected HEK293T cells by the whole-cell patch clamp recording assay at the concentration of 40 µM. Among the new skeleton compounds, 7d showed the highest efficacy (IC50 = 2.7 µM) and good selectivity (peak/late ratio >30 folds), as well as excellent pharmacokinetics properties in mice (T1/2 of 3.5 h, F = 90%, 3 mg/kg, po). It exhibited low hERG inhibition and was able to reverse the ATX-II-induced augmentation of late INa phenotype of LQT3 model in isolated rabbit hearts. These results suggest the application potentials of 7d in the treatments of arrhythmias related to the enhancement of late INa.

MiR-99a-5p inhibits bladder cancer cell proliferation by directly targeting mammalian target of rapamycin and predicts patient survival.

Bladder cancer is a common malignancy and miR-99a-5p has been reported to be downregulated in bladder cancer, but its function and the underlying mechanism in bladder cancer development remains largely unclear. Here, we report that miR-99a-5p expression was decreased in bladder cancer compared with the adjacent normal tissues. Receiver operating characteristic curve revealed that miR-99a-5p expression signature had area under curve value of 0.7989 in differing bladder cancer from the adjacent normal tissues. Bladder cancer patients with low expression of miR-99a-5p had a poor survival rate. Gain-of-function and loss-of-function approaches demonstrated that miR-99a-5p inhibited bladder cell proliferation and cell cycle. Furthermore, we identified that mammalian target of rapamycin (mTOR) was a direct target of miR-99a-5p and mTOR restore could rescue the proliferative ability of bladder cancer cells. Moreover, miR-99a-5p/mTOR axis regulated S6K1 phosphorylation. These suggested that miR-99a-5p/mTOR axis might be a therapeutic target for bladder cancer.

The role of fascin in migration and invasion of urothelial carcinoma of the bladder.

INTRODUCTION: To investigate the roles of fascin in migration and invasiveness in bladder urothelial carcinoma. MATERIALS AND METHODS: Immunohistochemical detection of fascin in urothelial carcinoma samples and inhibition the expression of fascin in the urothelial carcinoma cell line were performed, then the differences in cell behaviors before and after silencing of the fascin gene were tested. RESULTS: In our study, we found that overexpression of fascin was more frequent in urothelial carcinoma tissues (p < 0.001). Fascin expression was positively correlated with histological grade (p = 0.024) and pT stage (p < 0.001). After transfection of fascin shRNA, the expressions of fascin in 5637 cells and BIU87 cells were efficiently decreased according to real-time RT-PCR and Western blot analysis. When fascin was inhibited, a significant decrease in migration and invasion, and increase in adhesion were observed in 5637 cells and BIU87 cells. However, there was no significant change in the proliferation of 5637 cells or BIU87 cells with or without inhibition of the fascin gene. CONCLUSIONS: Fascin expression can be used as a predictor for transformation and progression of urothelial carcinoma, and reduction of fascin levels may represent a novel therapeutic strategy for urothelial carcinoma of the bladder.

Fascin is a predictor for invasiveness and recurrence of urothelial carcinoma of bladder.

OBJECTIVES: To evaluate the expression of fascin in bladder urothelial carcinoma, and to analyze its association with clinicopathologic features and prognosis of urinary bladder urothelial carcinoma. MATERIALS AND METHODS: Immunohistochemistry was used to detect the expression of fascin, Ki-67, p53, CK20, and multidrug resistance gene (MDR) in 111 bladder urothelial carcinoma and 42 normal epithelial tissues. The association between fascin expression and clinicopathologic parameters and prognostic factors on tumor recurrence was analyzed by Kaplan-Meier method, log-rank test, and Cox proportional hazards model. RESULTS: Ninety-four of 111 cases of bladder urothelial carcinoma showed positive fascin expression, while no fascin expression was detected in normal transitional epithelium. There was a significant difference in the expression of fascin in normal epithelium and bladder urothelial carcinoma (P = 0.000). Fascin expression was positively correlated with pT stage (P = 0.001) and tumor size (P = 0.011), while it had no association with age, gender, and tumor grade (P > 0.05). pT stage and the expression of fascin, Ki-67, p53, and CK20 were significantly correlated with urothelial carcinoma recurrence, and fascin expression was an independent factor predicting tumor recurrence. CONCLUSIONS: Fascin expression was up-regulated in bladder urothelial carcinoma. Over-expression of fascin might play an important role in invasiveness and recurrence of bladder urothelial carcinoma. Fascin may be used as a prognostic marker and a new target for the treatment of bladder urothelial carcinoma.