Circ_0000069 contributes to the growth,metastasis and glutamine metabolism in renal cell carcinoma (RCC) via regulating miR-125a-5p-dependent SLC1A5 expression

BackgroundCircular RNAs (circRNAs) have emerged as critical mediators in various cancers, including renal cell carcinoma (RCC). In the present research, the functions of circ_0000069 in RCC were explored.MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) assay, western blot assay and immunohistochemistry (IHC) assay were performed for the expression of circ_0000069, microRNA-125a-5p (miR-125a-5p) and solute carrier family 1 member 5 (SLC1A5). Cell Counting Kit-8 (CCK-8) assay and 5′-ethynyl-2′-deoxyuridine (EdU) assay were performed for cell proliferation. Flow cytometry assay was manipulated for cell apoptosis. Transwell assay and wound-healing assay were utilized for cell invasion and migration. Glutamine metabolism level was evaluated by examining glutamine consumption, α-ketoglutarate production and glutamate production. Dual-luciferase reporter assay was used to analyze the relationships of circ_0000069, miR-125a-5p and SLC1A5. Murine xenograft model assay was conducted to analyze the function of circ_0000069 in vivo.ResultsCirc_0000069 level was abnormally upregulated in RCC tissues and cells. Knockdown of circ_0000069 inhibited the proliferation, invasion, migration and glutamine metabolism and promoted the apoptosis in RCC cells in vitro and restrained tumor growth in vivo. Circ_0000069 served as the sponge for miR-125a-5p. MiR-125a-5p inhibition ameliorated the effects of circ_0000069 knockdown on RCC cell malignant behaviors. SLC1A5 was identified as the target gene of miR-125a-5p. Moreover, miR-125a-5p overexpression repressed the progression of RCC cells, while SLC1A5 elevation abrogated the effect.ConclusionCirc_0000069 knockdown inhibited the carcinogenesis of RCC by regulating miR-125a-5p/SLC1A5 axis.     

Circ_0000274 contributes to renal cell carcinoma progression by regulating miR-338-3p/NUCB2 axis and JAK1/STAT3 pathway

BackgroundKidney transplant recipients (KTRs) are at increased risk of developing renal cell carcinoma (RCC). Accumulating evidence has demonstrated that circular RNAs (circRNAs) are essential players in tumor advancement. However, the functions of circ_0000274 in renal cell carcinoma (RCC) are barely explored.MethodsThe primary RCC cell lines 786-O and A498 were used in this study. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was employed for the RNA levels of circ_0000274, microRNA-338-3p (miR-338-3p) and nucleobindin 2 (NUCB2). RNase R assay was conducted to analyze the feature of circ_0000274.Cell Counting Kit-8 (CCK-8) assay, colony formation assay, transwell assay, tube formation assay and flow cytometry analysis were conducted for cell viability, colony formation, metastasis, angiogenesis and apoptosis, respectively. Western blot assay was utilized for protein levels. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were adopted to analyze the associations of circ_0000274 RNA, miR-338-3p RNA and NUCB2 protein. Murine xenograft model was established to explore the function of circ_0000274 RNA in vivo. Immunohistochemistry (IHC) assay was used to analyze NUCB2 protein level in xenograft tumors.ResultsCompared to normal tissues and cells, circ_0000274 RNA level was elevated in RCC tissues and cells. Knockdown of circ_0000274 RNA suppressed cell viability, colony formation, metastasis and tube formation and promoted apoptosis in RCC cells in vitro. Circ_0000274 RNA sponged miR-338-3p RNA to positively regulate NUCB2 protein in RCC cells. Inhibition of miR-338-3p reversed the impacts of circ_0000274 knockdown on RCC cell malignant behaviors. MiR-338-3p RNA overexpression repressed the malignant phenotypes of RCC cells, while NUCB2 protein elevation could abrogate the effect. Moreover, circ_0000274 RNA knockdown blocked tumorigenesis in vivo. Besides, circ_0000274 RNA knockdown inactivated the JAK1/STAT3 protein signaling pathway.ConclusionCirc_0000274 RNA functioned as an oncogene in RCC development by regulating miR-338-3p RNA/NUCB2 protein axis and activating the JAK1/STAT3 protein signaling pathway.     

Long non-coding RNA LINC01116 accelerates the progression of keloid formation by regulating miR-203/SMAD5 axis

BackgroundEmerging evidence reveals the importance of long non-coding RNAs (lncRNAs) in the development and progression of keloid formation. However, the roles and molecular mechanism of lncRNA LINC01116 in the progression of keloid formation remain largely unknown.MethodsThe expression levels of LINC01116, microRNA-203 (miR-203) and SMAD family member 5 (SMAD5) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Cell proliferation, migration and invasion were detected by Cell counting Kit-8 (CCK-8) assay and transwell assay. Flow cytometry and western blot assay were used to examine cell apoptosis and extracellular matrix (ECM) production. The interaction between miR-203 and LINC01116 or SMAD5 was predicted by bioinformatics analysis and verified by dual-luciferase reporter and RNA Immunoprecipitation (RIP) and RNA pull-down assays.ResultsLINC01116 and SMAD5 were upregulated while miR-203 was downregulated in keloid tissues and keloid fibroblasts. LINC01116 knockdown suppressed the proliferation, migration, invasion, and ECM production but induced apoptosis in keloid fibroblasts through enhancing miR-203 and inhibiting SMAD5. Moreover, SMAD5 was identified as a direct target of miR-203 and miR-203 could directly bind to LINC01116. Besides, LINC01116 regulated SMAD5 expression by targeting miR-203.ConclusionDownregulation of LINC01116 inhibited the progression of keloid formation by regulating miR-203/SMAD5 axis, which might provide a novel target for keloid therapy.     

MicroRNA-199a-3p在肾癌中的表达及作用

目的 检测microRNA-199a-3p(miR-199a-3p)在肾癌细胞株和组织中的表达情况并探究miR-199a-3p在肾癌细胞中的作用.方法 利用实时定量RT-PCR检测miR-199a-3p在肾癌细胞和组织中的表达水平;利用miR-199a-3p模拟物转染肾癌细胞786-0上调miR-199a-3p后,通过CCK-8、克隆形成、Transwell以及细胞周期检测来探究其在肾癌细胞中的作用.结果 miR-199a-3p在肾癌细胞中明显低表达,在78%(14/18)的肾癌组织中亦明显低表达;上调miR-199a-3p可显著抑制肾癌细胞的增殖、存活和侵袭并能诱导细胞周期G1期阻滞.结论 我们的研究显示在肾癌中miR-199a-3p明显低表达并参与肾癌的发生、发展,这表明miR-199a-3p具有作为肾癌诊断和治疗靶点的潜能.     

MiRNA-148a inhibits cell growth and drug resistance by regulating WNT10a expression in renal cell carcinoma

BackgroundWe aimed to explore miR-148a exerts a tumor suppressor effect and arsenic trioxide (As₂O₃) sensitivity on renal cell carcinoma (RCC).MethodsWe performed polymerase chain reaction (PCR) on 42 pairs of tumor and paracancerous samples collected from RCC patients to investigate the miR-148a expression; meanwhile, we analyzed the interplay between clinical indicators and miR-148a expression of RCC. Then, the influence of miR-148a overexpression on the functions of RCC cells were analyze using transwell migration assay, Cell Counting Kit-8 (CCK-8), and cell wound healing assay. Furthermore, the ability of miR-148a to sensitize Caki-1 cells treated with As₂O₃ were detected using flow cytometry. Finally, the relevant mechanism of miR-148a on the downstream gene Wnt family member 10A (WNT10a) was explored by cell reverse method.ResultsThe results from RCC patients indicated a significantly lower miR-148a level than adjacent tissues. The low miR-148a expression increased prevalence of distant metastasis and decreased survival rate compared to those with high expression in patients. In the RCC cell lines, the proliferation and metastasis ability of the miR-148a mimic group was remarkably lower than the miR-NC group. At the same time, it was verified that WNT10a was remarkably higher cell lines and RCC tissues; and negatively related to miR-148a expression. In addition, miR-148a mimics were found to remarkably reduce the protein expression of WNT10a. In the cell reverse experiment, overexpression of WNT10a was confirmed to offset the miR-148a mimics effect on metastasis and proliferation of RCC cells. In addition, an increase in relative apoptosis was detected in As₂O₃ treated with/without miR-148a mimics for 48 hours, and apoptosis was significantly reduced after transfection with WNT10a in the Caki-1 cell line and significantly reduced after combined treatment.ConclusionsThe study revealed that miR-148a is associated with distant metastases and leads to poor prognosis in RCC patients. Moreover, miR-148a inhibit the malignant progression and increase the sensitivity of RCC cells to As₂O₃ by regulating WNT10a.     

MiR-134通过靶向调节KRAS抑制786-0肾透明细胞癌细胞上皮间质转化过程

目的探索miR-134在肾癌组织中的表达并研究其对肾透明细胞癌细胞786-0上皮间质转化的影响。方法采用逆转录-聚合酶链反应(RT-PCR)检测miR-134在20对肾癌组织和786-0细胞中的表达情况;miR-134模拟物转染786-0后,划痕实验和Transwell实验分别检测肾癌细胞迁移和侵袭能力的改变情况,Western blot检测细胞中靶蛋白KRAS及其相关信号通路蛋白表达情况;双荧光素酶报告基因检测miR-134与KRAS 3′-UTR结合情况。结果 MiR-134在20对肾癌组织和786-0细胞中明显低表达(P0.01);miR-134模拟物转染后能够抑制肿瘤细胞侵袭(P0.01)和迁移的能力(P0.05),显著降低肿瘤细胞中KRAS蛋白的水平(P0.05)并抑制RAS/MAPK/ERK通路中关键蛋白p-ERK的表达(P0.05);双荧光素酶报告基因显示miR-134能与KRAS 3′-UTR结合,显著降低荧光值(P0.05)。结论 MiR-134在肾透明细胞癌中显著低表达,能通过靶向抑制KRAS表达调控下游RAS/MAPK/ERK通路活性,阻滞786-0细胞上皮间质转化过程,抑制肿瘤细胞的侵袭和转移。     

长链非编码RNA LINC00313与miR-342-3p/膜联蛋白A2轴在肝细胞癌细胞中的作用与机制

背景与目的 肝细胞癌（HCC）是造成癌症相关性死亡的常见原因之一，研究表明长链非编码RNA（lncRNA）调控微小RNA（miRNA）的表达，进而通过抑制靶mRNA翻译或促进mRNA降解来参与肿瘤发生及进展过程。LINC00313作为一种具有致癌活性的lncRNA参与肿瘤发生及进展过程；膜联蛋白A2（ANXA2）在包括HCC的多种恶性肿瘤中表达上调，促进恶性表型的发生，并可能受上游miR-342-3p的调控。因此，本研究探讨LINC00313、miR-342-3p、ANXA2在HCC细胞中的表达及其相互关系。方法 用qRT-PCR与Western blot检测人肝实质细胞及HCC细胞系（Li-7、HuH-7、Hep3B2.1-7）中LINC00313、miR-342-3p及ANXA2表达。将体外培养的Li-7细胞分为空白对照组（无处理）、LINC00313 siRNA组（转染LINC00313 siRNA）、miR-342-3p模拟物组（转染miR-342-3p模拟物）、共转染阴性对照组（转染阴性siRNA序列与阴性miRNA序列）、共转染组（转染LINC00313 siRNA及miR-342-3p抑制物），用qRT-PCR与Western blot检测各组细胞LINC00313、miR-342-3p及ANXA2表达；MTT实验及平板集落形成实验检测各组细胞增殖；进行TUNEL染色检测各组细胞凋亡；Transwell侵袭及Western blot分别检测各组细胞侵袭数目及上皮-间充质转化（EMT）相关蛋白波形蛋白（vimentin）、E-钙黏蛋白（E-cadherin）表达；免疫荧光染色检测各组细胞Bcl-2关联X蛋白（Bax）/B淋巴细胞瘤-2（Bcl-2）；双荧光素酶报告实验分析Li-7细胞中LINC00313对miR-342-3p、miR-342-3p对ANXA2的靶向调控。建立皮下裸鼠异种移植瘤模型，验证LINC00313沉默对Li-7细胞体内生长的影响。结果 与人肝实质细胞比较，Li-7、HuH-7、Hep3B2.1-7细胞的LINC00313、ANXA2 mRNA及蛋白表达均明显升高，而miR-342-3p表达均明显降低（均P<0.05）。与对照组比较，LINC00313 siRNA组、miR-342-3p模拟物组细胞ANXA2 mRNA及蛋白表达、增殖率、集落生成率、侵袭细胞数目、vimentin蛋白表达均明显降低（P<0.05），miR-342-3p表达、凋亡率、E-cadherin蛋白表达、Bax/Bcl-2比值均明显升高（均P<0.05）；与LINC00313 siRNA组比较，共转染组细胞ANXA2 mRNA及蛋白表达、增殖率、集落生成率、侵袭细胞数目、vimentin蛋白表达均明显升高，而miR-342-3p表达、凋亡率、E-cadherin蛋白表达、Bax/Bcl-2比值均明显降低（均P<0.05）。Li-7细胞中，LINC00313可靶向下调miR-342-3p表达，miR-342-3p可靶向下调其ANXA2表达（均P<0.05）。体内实验结果显示，与无处理的Li-7细胞移植瘤比较，LINC00313敲低的Li-7细胞移植瘤的体积与质量均明显降低，肿瘤组织中LINC00313、ANXA2 mRNA及蛋白表达均明显降低，而miR-342-3p表达明显升高（均P<0.05）。结论 LINC00313在HCC细胞中的表达上调，LINC00313可能通过抑制miR-342-3p而增加后者靶基因ANXA2的表达，进而促进HCC细胞的恶性表型。     

miR-195-5p通过靶向ROCK1抑制肾癌细胞迁移、侵袭和上皮-间质转化

目的探讨miR-195-5p对肾癌细胞迁移、侵袭和上皮-间质转化的影响。方法通过转染miR-195-5p mimics或inhibitors分别过表达或抑制肾癌细胞中miR-195-5p的表达,转染靶向Rho相关螺旋蛋白激酶1(ROCK1)的小干扰RNA敲低肾癌细胞中ROCK1的表达量,利用细胞划痕实验和Transwell小室实验分别检测肾癌细胞的迁移和侵袭能力。通过双荧光素酶报告实验验证miR-195-5p对ROCK1的靶向调控作用,利用免疫印迹试验检测ROCK1及上皮-间质转化相关蛋白的表达水平。结果过表达miR-195-5p可显著抑制肾癌细胞的迁移、侵袭和上皮-间质转化,而抑制miR-195-5p的表达可明显促进肾癌细胞的迁移、侵袭和上皮-间质转化(P<0.05)。miR-195-5p可通过靶向ROCK1调控其在肾癌细胞中表达。敲低ROCK1后可部分抵消miR-195-5p inhibitors对肾癌细胞迁移、侵袭和上皮-间质转化的影响。结论miR-195-5p可通过靶向ROCK1抑制肾癌细胞的迁移、侵袭和上皮-间质转化。     

Depletion of circ_0006459 protects human brain microvascular endothelial cells from oxygen-glucose deprivation-induced damage through the miR-940/FOXJ2 pathway

BackgroundMultiple circular RNAs (circRNAs) play important roles in ischemic stroke. The present study aims to reveal the role and the mechanism of circ_0006459 in ischemic stroke.MethodsHuman brain microvascular endothelial cells (HBMECs) were treated with oxygen-glucose deprivation (OGD) to mimic an in vitro ischemic stroke model. RNA expression of circ_0006459, microRNA-940 (miR-940), and forkhead box J2 (FOXJ2) was detected by quantitative real-time polymerase chain reaction. Cell proliferation was analyzed by cell counting kit-8 (CCK-8) and 5-Ethynyl-29-deoxyuridine (EdU) assays. Cell apoptotic rate was quantified by flow cytometry analysis. The protein expression of proliferating cell nuclear antigen (PCNA), clusters of differentiation 6 (CDK6), BCL2-associated x protein (Bax), B-cell lymphoma 2 (Bcl2), interleukin-1β (IL-1β), IL-8, IL-18 and tumor necrosis factor-α (TNF-α) was analyzed by Western blotting. The regulatory relationships among circ_0006459, miR-940, and F 《人生只有一件事》 OXJ2 were identified by dual-luciferase reporter assay, RNA immunoprecipitation assay, and RNA pull-down assay.ResultsCirc_0006459 and FOXJ2 expression were significantly upregulated, whereas miR-940 expression was downregulated in HBMECs after OGD. Circ_0006459 depletion assuaged OGD-induced inhibition in cell proliferation and promotion in cell apoptosis and inflammation in HBMECs. Circ_0006459 acted as a sponge for miR-940, and miR-940 targeted FOXJ2 in HBMECs. Besides, miR-940 silencing or FOXJ2 overexpression relieved circ_0006459 knockdown-induced promotion in cell proliferation and inhibition in cell apoptosis and inflammation in OGD-induced HBMECs. Further, circ_0006459 depletion decreased FOXJ2 protein expression by interacting with miR-940.ConclusionDepletion of circ_0006459 protected human brain microvascular endothelial cells from oxygen-glucose deprivation-induced damage through miR-940/FOXJ2 pathway, providing a promising therapeutic target for ischemic stroke.     

CircCOL5A1 inhibits proliferation,migration, invasion,and extracellular matrix production of keloid fibroblasts by regulating the miR-877-5p/EGR1 axis

BackgroundCircular RNA (circRNA) has been proved to mediate the biological functions of fibroblasts to participate in the regulation of keloid formation. However, the role of circCOL5A1 in keloid formation remains to be further confirmed.MethodsPrimary keloid fibroblasts were isolated form keloid tissues. The expression of circCOL5A1, microRNA (miR)? 877–5p, and early growth response 1 (EGR1) were determined by quantitative real-time PCR. Transfection experiments were carried out to explore the effects of circCOL5A1, miR-877–5p, and EGR1 on cell functions. Cell proliferation, migration, invasion and apoptosis were detected using cell counting kit 8 assay, colony formation assay, transwell assay and flow cytometry. The protein levels of apoptosis markers, extracellular matrix (ECM) markers and EGR1 were measured by western blot analysis. The mechanism of circCOL5A1 was confirmed by RNA pull-down assay, dual-luciferase reporter assay and RIP assay.ResultsOur data showed that circCOL5A1 was upregulated in keloid tissues and fibroblasts. Silencing of circCOL5A1 had an inhibition effect on proliferation, migration, invasion and ECM production, while had a promotion effect on apoptosis in keloid fibroblasts. MiR-877–5p could be sponged by circCOL5A1, and its overexpression could repress the biological functions of keloid fibroblasts. The rescue experiments showed that miR-877–5p inhibitor could reverse the suppressive effect of circCOL5A1 knockdown on the biological functions of keloid fibroblasts. In addition, EGR1 was a target of miR-877–5p, and its expression was positively regulated by circCOL5A1. The inhibition effect of miR-877–5p on the biological functions of keloid fibroblasts could be abolished by EGR1 overexpression.ConclusionIn summary, circCOL5A1 facilitates keloid fibroblast proliferation, migration, invasion and ECM production through the miR-877–5p/EGR1 axis, thereby potentially promoting keloid formation.     

MiR-133a induces apoptosis through direct regulation of GSTP1 in bladder cancer cell lines

ObjectiveWe previously demonstrated that miR-133a is a tumor-suppressive microRNA (miRNA) and is commonly down-regulated in human bladder cancer (BC). The aim of this study is to determine a novel oncogenic gene targeted by miR-133a in BC.MethodsTo identify genes targeted by miR-133a, an oligo-microarray analysis was performed using the miR-133a-transfected BC cell lines. For gain/loss-of-function studies, miR-133a/si-glutathione S-transferase π1 (GSTP1)-transfectants were subjected to XTT assay and flow cytometry to evaluate their cell viability and apoptosis status. The luciferase reporter assay was used to confirm the actual binding sites between miR-133a and GSTP1 mRNA. The mRNA and protein expression of GSTP1 in BC cell lines and clinical samples were evaluated by real-time RT-PCR and Western blot, respectively.ResultsMiR-133a transfection induced cell viability inhibition and apoptosis in BC cell lines. We focused on the GSTP1 gene that was the top 7 down-regulated one in the gene profile from the miR-133a-transfectants. MiR-133a transfection repressed expression levels of mRNA and protein levels of GSTP1. A luciferase reporter assay suggested that the actual binding may occur between miR-133a and GSTP1 mRNA. Cell viability inhibition and apoptosis were induced in the si-GSTP1 transfectants compared with the controls (P < 0.005). GSTP1 mRNA expression levels in 43 clinical BCs were significantly higher than those in eight normal bladder epitheliums (P = 0.0277).ConclusionOur data suggest that tumor suppressive miR-133a directly regulated oncogenic GSTP1 gene in BC, and that an anti-apoptotic effect mediated by GSTP1 is maintained by miR-133a down-regulation in human BC.     

A microRNA expression ratio defining the invasive phenotype in bladder tumors

ObjectiveThe goal of this study was to identify a microRNA (miRNA) signature in bladder cancer capable of differentiating superficial from invasive disease.MethodsExpression profiling of 343 miRNAs was performed in a microarray format using noninvasive and invasive bladder carcinoma cell lines with differential expression confirmed using a single molecule detection platform assay. miR-21 and miR-205 expression levels were determined in 53 bladder tumors (28 superficial and 25 invasive). Sensitivity, specificity, and a ROC curve were calculated to determine the discriminatory power of the miRNA ratio to predict invasion. Knockdown and forced expression of miRNAs was performed to evaluate their role in invasion.ResultsExpression profiling of 343 miRNAs, using noninvasive and invasive bladder cell lines, revealed significant differential expression of 9 miRNAs. Cell lines characterized as invasive showed a miR-21:miR-205 ratio at least 10-fold higher than the quantitative ratio obtained from non-invasive cell lines. The same expression ratio was determined in 53 bladder tumors. From these results, we recorded a sensitivity and specificity of 100% and 78%, respectively, using a cutoff of 1.79 to predict an invasive lesion. The area under the receiver operator characteristic curve was 0.89. Using in vitro invasion assays, we have demonstrated a role for miR-21 in establishing the invasive phenotype of bladder carcinoma cells.ConclusionIn this study, we identified a miR-21:miR-205 expression ratio that has the ability to distinguish between invasive and noninvasive bladder tumors with high sensitivity and specificity, with the potential to identify superficial lesions at high risk to progress.     

Benzodiazepines safeguards nerve cells from the toxicity of lidocaine via miR-133a-3p/EGFR pathway

BackgroundLidocaine was an anesthetic commonly used for analgesia, but the neurotoxicity could not be ignored. However, benzodiazepines could alleviate the toxicity when combined with other drugs.PurposeTo explore the molecular mechanism of benzodiazepines in protecting nerve cells after the induction of lidocaine.MethodsPC12 cells were induced by lidocaine (0 mM, 0.1 mM, 0.5 mM and 1 mM) first and then treated by benzodiazepines (0 μM–200 μM). RT-qPCR assays measured RNA expressions of epidermal growth factor receptor (EGFR) and microRNA-133a-3p (miR-133a-3p) in PC12 cell line, respectively. Western blot was for protein detections of EGFR and caspase-3. Flow cytometry assay assessed apoptosis and cellular viability was validated via Cell Counting Kit-8 (CCK-8) test. Bioinformatics analysis predicted the potential link between miR-133a-3p and EGFR and the binding was verified using the Dual luciferase reporter experiment.ResultsBenzodiazepines increased cellular viability of PC12 cells up to 100 μM while suppressed viability between 100 and 200 μM. Benzodiazepines (0 μM, 10 μM, 50 μM and 100 μM) did not regulate PC12 cell viability but promoted the viability of lidocaine-treated PC12 cells. Lidocaine downregulated miR-133a-3p RNA expression but facilitated EGFR mRNA expression, which was reversed after treated by benzodiazepines. MiR-133a-3p targeted and negatively regulated EGFR expressions in mRNA and protein levels. Furthermore, miR-133a-3p inhibitor and overexpressed EGFR transfection both restrained the decreased PC12 cell viability and prompted cell apoptosis caused by benzodiazepines.ConclusionBenzodiazepines restrained lidocaine-induced toxicity in PC12 cells which secured viability and reduced apoptosis via miR-133a-3p/EGFR pathway.     

miR-145 inhibits invasion of bladder cancer cells by targeting PAK1

ObjectivesMicroRNAs play important roles in cancer. In many cancers, miR-145 acts as a tumor suppressor, and it is down-regulated in bladder cancer. In the present study, we explored the modulation of oncogenic gene PAK1 by miR-145 in bladder cancer.Material and methodsExpression of miR-145 was detected in bladder cancer tissues and cell lines by quantitative real-time polymerase chain reaction. Through the bioinformatics approach, PAK1 has been predicted to be a direct target of miR-145 and was confirmed by the PAK1 messenger RNA 3′-untranslated region luciferase activity assay. To investigate whether miR-145 regulates PAK1 expression, it was overexpressed in J82 and T24 bladder cancer cells. In 10 paired bladder normal and tumor tissues, we determined the relationship between miR-145 and PAK1 through quantitative real-time polymerase chain reaction and western blot. By using transwell invasion assay and western blotting analysis, we investigated the effects of miR-145 and PAK1 on bladder cancer cell invasion and expression of invasion marker genes.ResultsThe level of miR-145 decreases and PAK1 protein expression up-regulates in bladder cancer tissue, as compared with the paired normal bladder tissue. Moreover, miR-145 directly targets PAK1 in bladder cancer cells. The level of miR-145 negatively correlates with PAK1 protein expression in bladder cancer. In addition, PAK1 promotes invasion and enhances the expression and activity of MMP-9, whereas miR-145 inhibits bladder cancer cell invasion and expressions of PAK1 and MMP-9.ConclusionsOur results indicate that miR-145 inhibits bladder cancer cell invasion, at least partly through targeting PAK1. Restoration or replacement of miR-145 could be an efficient approach to inhibit PAK1 and bladder cancer development in the tumor therapy.