miR-5590-3p inhibits the proliferation and metastasis of renal cancer cells by targeting ROCK2 to inhibit proliferation, migration and invasion.

The present study aimed to clarify the role of microRNA (miR)-5590-3p in the progression of renal cell carcinoma (RCC) and investigate the underlying mechanisms. The expression levels of miR-5590-3p, Rho-associated protein kinase (ROCK)2 and ß-catenin in RCC cells were measured by reverse transcription-quantitative PCR and western blot analysis. Following overexpression of miR-5590-3p and ROCK2 by transfection of miR-5590-3p mimics and GV367-ROCK2, respectively, changes in the proliferation, migration and invasion of RCC cells were determined through colony-formation, wound-healing and Transwell assays, respectively. The direct binding interaction between miR-5590-3p and ROCK2, initially predicted using Targetscan, was validated by a dual-luciferase reporter assay. The results indicated that miR-5590-3p was downregulated in RCC. Overexpression of miR-5590-3p led to downregulation of ROCK2 and ß-catenin and inhibited the proliferation, migration and invasion of RCC cells. The dual-luciferase reporter assay confirmed the binding relationship between miR-5590-3p and ROCK2. Of note, overexpression of ROCK2 effectively reversed the regulatory effects of miR-5590-3p on RCC cells. In conclusion, miR-5590-3p inhibits the proliferation, migration and invasion of RCC cells by targeting ROCK2, which is a potential molecular biomarker and therapeutic target for RCC.

Nc886 promotes renal cancer cell drug-resistance by enhancing EMT through Rock2 phosphorylation-mediated ß-catenin nuclear translocation.

Drug resistance is a significant challenge in the present treatment regimens of renal cell carcinoma (RCC). Our previous study confirmed that nc886 functions as an oncogene in RCC. Nevertheless, the role and underlying mechanism of nc886 in RCC drug resistance are unclear. In the present study, Sunitinib and Everolimus treatment, respectively, downregulated nc886 expression in a dose-dependent manner in all four renal cancer cell lines. Nc886 overexpression in 786-O cells and ACHN cells significantly reduced the sensitivity of cancer cells to both Sunitinib and Everolimus treatment, respectively, by promoting cell viability and inhibiting cell apoptosis, whereas nc886 silencing increased cancer cell sensitivity. In renal cancer cell line with the highest drug-resistance, 786-O cells, Sunitinib, or Everolimus treatment enhanced the cellular EMT and was further enhanced by nc886 overexpression while attenuated by nc886 silencing. In 786-O cells, nc886 overexpression significantly promoted EMT, ROCK2 phosphorylation, and ß-catenin nucleus translocation under Sunitinib or Everolimus treatment. Moreover, ROCK2 silencing significantly reversed the effects of nc886 overexpression on EMT, ROCK2 phosphorylation, and ß-catenin nucleus translocation, as well as drug-resistant renal cancer cell viability and apoptosis. In conclusion, it was demonstrated that nc886 promotes renal cancer cell proliferation, migration, and invasion, as demonstrated previously. nc886 also promotes renal cancer cell drug-resistance to Sunitinib or Everolimus by promoting EMT through Rock2 phosphorylation-mediated nuclear translocation of ß-catenin.

CSN5 promotes renal cell carcinoma metastasis and EMT by inhibiting ZEB1 degradation.

CSN5 (also known as COPS5) is a newly characterized oncogene involved in various types of cancer. However, its expression pattern and biological functions in renal cell carcinoma (RCC) is unknown. Here, we found that CSN5 expression was elevated in RCC tissues than those in paired normal renal tissues. Additionally, we demonstrated that high CSN5 level was closely correlated with tumor progression and poor survival in RCC patients. Our results showed that increased expression of CSN5 was observed in RCC cell lines and knockdown of CSN5 significantly suppressed the migration and invasion of RCC cells in vitro and in vivo. Additionally, CSN5 contributes to the metastasis and EMT (epithelial-mesenchymal transition) of RCC cells. Further investigation revealed that CSN5 led to the metastasis and EMT activation of RCC cells through increasing ZEB1 expression. Mechanistically, we found that CSN5 directly bound ZEB1 and decreased its ubiquitination to enhance the protein stability of ZEB1 in RCC cells. Taken together, our data identified CSN5 as a critical oncoprotein involved in migration and invasion of RCC cells, which could serve as a potential therapeutic target in RCC patients.

Effect of MicroRNA-218 on the viability, apoptosis and invasion of renal cell carcinoma cells under hypoxia by targeted downregulation of CXCR7 expression.

OBJECTIVE: To investigate the effect of microRNA-218 on the viability, apoptosis and invasion of renal cell carcinoma cells under hypoxia by targeted regulation of expression of chemokine receptor 7 (CXCR7). METHODS: The expression of miR-218 in renal cell carcinoma cell lines under normal and hypoxia conditions, as well in normal renal tubular epithelial cells (HK2) was measured using RT-PCR. MiR-218 mimic and NC were transfected into renal cell carcinoma cell line ACHN using Lipofectamine™ 2000. The expression of miR-218 was analyzed using RT-PCR. The viability, apoptosis, migration and invasion of the transfected cells were assayed using the MTT assay, flow cytometry and transwell assays. The expression of CXCR7 was assayed using RT-PCR and Western blot. Luciferase reporter was used to verify the downstream target of miR-218. RESULTS: The expression of miR-218 was lower than in renal cell carcinoma cell lines ACHN, 769-p and Caki-1 that in HK-2. The expression of miR-218 in the renal carcinoma cell lines was lower under hypoxia than under normal oxygen conditions. The expression of miR-218 in ACHN cells under normal and hypoxic conditions was significantly increased after transfection with miR-218 mimic. Compared with NC transfected cells under normal oxygen condition, the mimic-transfected cells had reduced viability, migration ability and invasion ability, and increased apoptosis, and mimic transfected-cells under hypoxia had significantly reduced viability, migration ability and invasion ability, and increased apoptosis. Overexpression of miR-218 mimic resulted in significant reduction in the expression of CXCR7 at protein and mRNA levels under normal and hypoxic conditions. Luciferase reporter assay confirmed that CXCR7 is the target protein of miR-218. CONCLUSION: Up-regulation of miR-218 expression in renal cell carcinoma under hypoxia can result in significant and targeted down-regulation of CXCR7 expression, which could reduce cell viability, migration and invasion ability and induce apoptosis in the cancer cells.

Molecular validation of the precision-cut kidney slice (PCKS) model of renal fibrosis through assessment of TGF-ß1-induced Smad and p38/ERK signaling.

BACKGROUND: The precision-cut kidney slice (PCKS) model appears to be a useful ex vivo model of renal fibrosis. However, little in-depth molecular investigation on the PCKS model has been performed. Therefore, the aim of this study will be to investigate and validate the molecular validity of this model. METHODS: The PCKS model was constructed in male C57BL/6 mice. To induce renal fibrosis, PCKS were incubated in recombinant human TGF-ß1 for 48 h. Protein expression of phosphorylated Smad2 (p-Smad2, cytosolic and nuclear), Smad7, phosphorylated ERK1 (p-ERK1), phosphorylated ERK2 (p-ERK2), and phosphorylated p38 MAPK (p-p38 MAPK) was measured using Western blotting. To assess Smad2/3 heteromeric complex formation and phosphorylated Smad3 (p-Smad3) expression, immunoprecipitation was performed with an anti-Smad2 or an anti-Smad3 antibody, respectively, prior to Western blotting. RESULTS: p-Smad2 and p-Smad3 were significantly upregulated in the PCKS model relative to control (p<0.05). However, we found no significant difference in Smad7 expression between the PCKS model and control (p>0.05). The PCKS model demonstrated significantly greater Smad2/3 complex formation and nuclear translocation relative to control (p<0.05). The PCKS model showed significantly greater expression of p-ERK1, p-ERK2, and p-p38 MAPK relative to control (p<0.05). CONCLUSIONS: The PCKS model displays several well-established molecular markers of renal fibrosis. However, the PCKS model failed to display Smad7 downregulation and appears to display "over-activation" of p-Smad2 and p-Smad3 as well as "under-activation" of ERK1/2 and p38 MAPK signaling vis-à-vis the well-established in vivo unilateral ureteric obstruction model of renal fibrosis.

3-cinnamoyl-4-hydroxy-6-methyl-2H-pyran-2-one (CHP) inhibits human ovarian cell proliferation by inducing apoptosis.

Coumarins induce apoptosis by activating mitochondrial pathway and caspase-3-dependent apoptotic pathway. In the present study, we first time investigated the effect of 3-cinnamoyl-4-hydroxy-6-methyl-2H-pyran-2-one (CHP) on induction of apoptosis in human ovarian carcinoma cells. The data from MTT assay revealed a significant inhibitory effect on cell viability at 30 (87%) and 50 µM (74%) concentration of CHP in OVCAR-3 and OVCAR-420 cells, respectively after 72 h. Apoptosis analysis using annexin V/PI double staining followed by flow cytometry showed 59 and 52% binding to annexin V-FITC in OVCAR-3 and OVCAR-420 cells respectively. propidium iodide (PI) staining and flow cytometry examination indicated a significant increase in percentage of cells in G2/M phase after treatment with CHP compared to DMSO control group. Reactive oxygen species (ROS) assay kit showed increase in levels of ROS. We used rhodamine-123 (Rh-123) staining and flow cytometry assay to determine changes in mitochondrial membrane potential (ΛΨm). The results revealed that CHP significantly decreased MMP to 85.65 ± 1.2443% & 49.78 ± 1.6554% at 10 and 30 µM respectively in OVCAR-3 compared to 95.97 ± 2.1243% in control group. Western blot analysis clearly indicated a significant increase in the expression of Caspase-3, Bax, and release of Cytochrome c and decrease in Bcl-2, CDK1 and Cyclin B1 expression on treatment with CHP. Therefore, CHP may become a potential candidate for the treatment of human ovarian cancers.

X-ray irradiation promotes apoptosis of hippocampal neurons through up-regulation of Cdk5 and p25.

BACKGROUND: Cranial radiation therapy has been used for the treatment of primary and metastatic brain tumors. A prominent feature of brain injury induced by the radiation therapy is hippocampal dysfunction, characterized by a decline in memory. Cdk5 plays an important role in memory formation. Abnormal Cdk5 activity is associated with neuronal apoptosis induced by neurotoxic stimuli. However, the roles of Cdk5 in hippocampal apoptosis in response to X-ray irradiation have not been explored. METHODS: The expression of Cdk5 activators, p35 and p25, in hippocampal neurons was tested in both in vivo animal and in vitro couture after X-ray irradiation. RESULTS: After X-ray irradiation at 20 Gy and 30 Gy in rats, the number of hippocampal neuronal pyknosis was increased, but the number of hippocampal neuron was decreased, in the hippocampal CA1 region of rats. In these animals undergone with X-ray irradiation, the expression of p35 was significantly down-regulated, but it was up-regulated in p25. These opposite expressions were also shown in the primary cultured hippocampal neurons with 30 Gy irradiation. The apoptosis induced by X-ray irradiation were significantly prevented by the pretreatment of Cdk5 inhibitor, roscovitine, in both in vivo and in vitro settings. CONCLUSIONS: X-ray irradiation resulted in a hippocampal neuronal apoptosis through up-regulation of p25, the Cdk5 activator. Hyperactivity of Cdk5 was involved in the pathogenesis of X-ray irradiation-induced hippocampal neuronal apoptosis. Blockade of Cdk5 signal pathway effectively protected neurons from the irradiation-induced brain injury.

[p35 and p25 expressions and Cdk5 kinase activity in primary cultured rat hippocampal neurons with X-ray exposure].

OBJECTIVE: To study the expressions of p35 and p25 and Cdk5 kinase activity in cultured rats hippocampal neurons following X-ray exposure to provide experimental evidence for prevention and treatment of radiation encephalopathy. METHODS: The hippocampal neurons cultured for 12 days were subjected to a single-dose X-ray exposure of 30 Gy. Western blotting was used to detect the p35 and p25 protein levels, and the effect of pretreatment with roscovitine, a Cdk5 inhibitor, on the apoptosis of the hippocampal neurons following the exposure was examined with 4',6-diamidino-2-phenylindole (DAPI) staining. RESULTS: The protein level of p35 increased significantly 3.5 and 4 h after the irradiation by 1.51-/+0.13 and 1.45-/+0.14 folds in comparison with the control level, respectively (P<0.01), and the p25 level increased significantly 6 h after irradiation by 1.62-/+0.28 folds (P<0.05). Nuclear condensation occurred in (24.8-/+3.97)% of the neurons 24 h after 30 Gy X-ray exposure, a rate significantly higher than that in the nonexposed cells [(1.82-/+1.08)%, P<0.01) and that in roscovitine-pretreated neurons [(7.74-/+2.27)%, P<0.01). CONCLUSION: X-ray exposure activates Cdk5 by increasing the p35 and p25 expressions in rat hippocampal neurons, and inhibition of Cdk5 activity with roscovitine can significantly protect the neurons from apoptosis.