Tumor-suppressive microRNA-497 targets IKKß to regulate NF-κB signaling pathway in human prostate cancer cells.

BACKGROUND: Prostate cancer (PCa) is one of the most prevalent malignant tumors, PCa-related death is mainly due to the high probability of metastasis. MicroRNAs (miRNAs) play an important role in cancer initiation, progression and metastasis by regulating their target genes. METHODS: real-time PCR was used to detected the expression of microRNA-497. The molecular biological function was investigated by using cell proliferation assays, cell cycle assay, and migration and invasion assay. We used several Algorithms and confirmed that IKKß is directly regulated by miR-497. RESULTS: Here, we found miR-497 is downregulated in human prostate cancer (PCa) and inhibites the proliferation activity, migration and invasion of PC3-AR cells. Subsequently, IKKß is confi rmed as a target of miR-497. Furthermore, knockdown of IKKß expression resulted in decreased proliferation activity, migration and invasion. Finally, similar results was found after treatment with a novel IKK-ß inhibitor (IMD-0354) in PC3-AR cells. CDK8, MMP-9, and PSA were involved in all these process. CONCLUSION: Taken together, our results show evidence that miR-497 may function as a tumor suppressor genes by regulating IKK-ß in PCa, and may provide a strategy for blocking PCa metastasis.

Pirfenidone attenuates bladder fibrosis and mitigates deterioration of bladder function in a rat model of partial bladder outlet obstruction.

To investigate the effects of pirfenidone (PFD) on the attenuation of bladder remodeling, and the associated functional changes caused by partial bladder outlet obstruction (pBOO), the present study performed surgery on adult male Sprague­Dawley rats produce a model of pBOO. The rats in the pBOO group were administered a placebo and, in the CMC group, PFD mixed with the placebo was administered orally at 500 mg/kg body weight each day for 5 weeks, from 1 week after surgery. The rat bladders were harvested for biochemical analysis following cystometry at the end of the 6 week period. The histopathology was determined using Masson's trichrome staining. The mRNA and protein levels of pro­fibrotic growth factors and extracellular matrix subtypes were assessed. pBOO debilitated bladder function and caused the parameters from cystometry to increase significantly compared with those in the control group (P<0.05), which were mitigated significantly following PFD treatment (P<0.05). In terms of the histology, the rats in the pBOO group exhibited significant increases in bladder weight, muscle hypertrophy and deposition of collagens, which were suppressed by PFD treatment (P<0.05). Based on the biochemical analysis, significant increases in the mRNA levels of collagen subtypes and growth factors, and protein levels of profibrotic growth factors and α­smooth muscle actin in the bladders of rats in the pBOO group were reduced following PFD treatment. PFD prevented bladder remodeling and attenuated bladder fibrosis and, therefore, mitigated the deterioration of bladder function during the initial stage of pBOO.

MiR-133 modulates TGF-ß1-induced bladder smooth muscle cell hypertrophic and fibrotic response: implication for a role of microRNA in bladder wall remodeling caused by bladder outlet obstruction.

Bladder outlet obstruction (BOO) evokes urinary bladder wall remodeling significantly, including the phenotype shift of bladder smooth muscle cells (BSMCs) where transforming growth factor-beta1 (TGF-ß1) plays a pivotal role given the emerging function of modulating cellular phenotype. miR-133 plays a role in cardiac and muscle remodeling, however, little is known about its roles in TGF-ß1-induced BSMC hypertrophic and fibrotic response. Here, we verified BOO induced bladder wall remodeling and TGF-ß1 expression mainly located in bladder endothelium. Furthermore, we uncovered miR-133a/b expression profile in BOO rats, and then explored its regulated effects on BSMCs' phenotypic shift. Our study found that miR-133 became down-regulated during rat bladder remodeling. Next, we sought to examine whether the expression of miR-133 was down-regulated in primary BSMCs in response to TGF-ß1 stimulation and whether forced overexpression of miR-133 could regulate profibrotic TGF-ß signaling. We found that stimulation of BSMCs with exogenous TGF-ß1 of increasing concentrations resulted in a dose-dependent decrease of miR-133a/b levels and transfection with miR-133 mimics attenuated TGF-ß1-induced α-smooth muscle actin, extracellular matrix subtypes and fibrotic growth factor expression, whereas it upregulated high molecular weight caldesmon expression compared with the negative control. Also, downregulation of p-Smad3, not p-Smad2 by miR-133 was detected. Additionally, miR-133 overexpression suppressed TGF-ß1-induced BSMC hypertrophy and proliferation through influencing cell cycle distribution. Bioinformatics analyses predicted that connective tissue growth factor (CTGF) was the potential target of miR-133, and then binding to the 3'-untranslated region of CTGF was validated by luciferase reporter assay. These results reveal a novel regulator for miR-133 to modulate TGF-ß1-induced BSMC phenotypic changes by targeting CTGF through the TGF-ß-Smad3 signaling pathway. A novel antifibrotic functional role for miR-133 is presented which may represent a potential target for diagnostic and therapeutic strategies in bladder fibrosis.