miR-26a Suppresses Tumor Growth and Metastasis by Targeting FGF9 in Gastric Cancer

The role of miR-26a in cancer cells seemed controversial in previous studies. Until now, the role of miR-26a in gastric cancer remains undefined. In this study, we found that miR-26a was strongly downregulated in gastric cancer (GC) tissues and cell lines, and its expression levels were associated with lymph node metastasis and clinical stage, as well as overall survival and replase-free survival of GC. We also found that ectopic expression of miR-26a inhibited GC cell proliferation and GC metastasis in vitro and in vivo. We further identified a novel mechanism of miR-26a to suppress GC growth and metastasis. FGF9 was proved to be a direct target of miR-26a, using luciferase assay and western blot. FGF9 overexpression in miR-26a-expressing cells could rescue invasion and growth defects of miR-26a. In addition, miR-26a expression inversely correlated with FGF9 protein levels in GC. Taken together, our data suggest that miR-26a functions as a tumor suppressor in GC development and progression, and holds promise as a prognostic biomarker and potential therapeutic target for GC.     

Elevation of Soluble Guanylate Cyclase Suppresses Proliferation and Survival of Human Breast Cancer Cells

Nitric oxide (NO) is an essential signaling molecule in biological systems. Soluble guanylate cyclase (sGC), composing of α1 and β1 subunit, is the receptor for NO. Using radioimmunoassay, we discovered that activation of sGC by treatment with bradykinin or sodium nitroprusside (SNP) is impaired in MCF-7 and MDA-MB-231 breast cancer cells as compared to normal breast epithelial 184A1 cells. The 184A1 cells expressed both sGC α1 and sGCβ1 mRNAs. However, levels of sGCβ1 mRNAs were relatively lower in MCF-7 cells while both mRNA of sGC subunits were absent in MDA-MB-231 cells. Treatment with DNA methyltransferase inhibitor 5-aza-2’-deoxycytidine (5-aza-dC) increased mRNA levels of both sGCα1 and sGCβ1 in MDA-MB-231 cells but only sGCβ1 mRNAs in MCF-7 cells. The 5-aza-dC treatment increased the SNP-induced cGMP production in MCF-7 and MDA-MB-231, but not in 184A1 cells. Bisulfite sequencing revealed that the promoter of sGCα1 in MDA-MB-231 cells and promoter of sGCβ1 in MCF-7 cells were methylated. Promoter hypermethylation of sGCα1 and sGCβ1 was found in 1 out of 10 breast cancer patients. Over-expression of both sGC subunits in MDA-MB-231 cells induced apoptosis and growth inhibition in vitro as well as reduced tumor incidence and tumor growth rate of MDA-MB-231 xenografts in nude mice. Elevation of sGC reduced protein abundance of Bcl-2, Bcl-xL, Cdc2, Cdc25A, Cyclin B1, Cyclin D1, Cdk6, c-Myc, and Skp2 while increased protein expression of p53. Our study demonstrated that down-regulation of sGC, partially due to promoter methylation, provides growth and survival advantage in human breast cancer cells.     

Targeting Cadherin-17 Inactivates Ras/Raf/MEK/ERK Signaling and Inhibits Cell Proliferation in Gastric Cancer

Cadherin-17 (CDH17), one member of 7D-cadherin superfamily, was overexpressed in gastric cancer (GC) and was associated with poor survival, tumor recurrence, metastasis, and advanced tumor stage. So far the cellular function and signaling mechanism of CDH17 in GC remains unclear. In this study, we showed that over 66% of GC cell lines (20/30) were CDH17 positive. Tissue microarray (TMA) assay showed that 73.6% Chinese GC tissues (159/216) were CDH17 positive, while 37% respective adjacent normal tissues were CDH17 positive. Knockdown of CDH17 inhibited cell proliferation, migration, adhesion and colony formation, and also induced a cell cycle arrest and apoptosis in AGS human GC cells. On the other side, overexpression of CDH17 facilitated MGC-803 GC tumor growth in nude mice. Antibody array and Western blotting assay demonstrated that knockdown of CDH17 in AGS cells down-regulated integrin β series proteins, further inactivated the Ras/Raf/MEK/ERK pathway and led to p53 and p21 accumulation, which resulted in proliferation inhibition, cell-cycle arrest and apoptosis induction. Collectively, our data firstly demonstrate the capacity of CDH17 to regulate the activity of Ras/Raf/MEK/ERK pathway for cell proliferation in GC, and suggest that CDH17 can serve as an attractive therapeutic target for future research.     

花生四烯酸代谢相关酶和ERK与乳腺癌转移关系

花生四烯酸代谢相关酶环加氧酶(COX)、脂氧合酶(LOX)和活化的胞外信号调节激酶（p-ERK1/2）等与乳腺癌发生发展具有密切关系.为了进一步阐明它们在乳腺癌转移中的作用及其分子机制,应用反转录PCR（RT-PCR）、免疫印迹和免疫组化等方法,分别检测了乳腺癌细胞系、乳腺癌组织、癌旁组织和转移淋巴结组织中COX-2、5-LOX、12R-LOX、cPLA2和p-ERK1/2的表达水平.结果显示,与对照组相比,在具有高转移潜能的乳腺癌LM MCF-7细胞和MDA-MB-231细胞以及转移淋巴结组织中,COX-2、5-LOX、12R-LOX、cPLA2和p-ERK1/2均有较高水平表达.进而发现,p-ERK1/2的特异性抑制剂PD98059可拮抗LM-MCF-7细胞和MDA-MB-231细胞中COX-2、5-LOX、12R-LOX和cPLA2的高表达.上述结果表明,p-ERK1/2可以通过促进花生四烯酸代谢相关酶的表达促进乳腺癌细胞发生转移.     

miR-448通过抑制上皮间质转化抑制肺癌细胞增殖和运动能力

探讨mi R-448对肺癌细胞增殖和运动的影响及其分子机制。采用实时荧光定量PCR(polymerase chain reaction)检测原发肺癌组织和癌旁正常组织mi R-448表达水平。转染mi R-448 mimic和inhibitor至肺癌A549细胞系,通过MTT(3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazoliumbromide)、平板克隆形成和Transwell实验观察mi R-448表达对A549增殖和运动能力的影响;利用Western blot检测EMT(epithelial-mesenchymal transition)标志物蛋白表达水平,通过实时荧光定量PCR检测EMT相关转录因子m RNA表达水平。实时荧光定量PCR显示较癌旁正常组织相比,mi R-448在原发肺癌组织中表达降低。MTT和平板克隆形成实验显示,过表达mi R-448抑制A549细胞增殖和运动能力;降表达mi R-448增强A549细胞增殖和运动能力。Western blot显示降表达mi R-448能下调上皮标志物E-cadherin,上调间质标志物Vimentin表达水平。实时荧光定量PCR显示降表达mi R-448能上调EMT相关转录因子Twist1和ZEB1 m RNA表达水平。mi R-448可通过抑制EMT抑制肺癌进展。     

Down-Regulating Overexpressed Human Lon in Cervical Cancer Suppresses Cell Proliferation and Bioenergetics

The human mitochondrial ATP-dependent Lon protease functions in regulating the metabolism and quality control of proteins and mitochondrial DNA (mtDNA). However, the role of Lon in cancer is not well understood. Therefore, this study was undertaken to investigate the importance of Lon in cervical cancer cells from patients and in established cell lines. Microarray analysis from 30 cancer and 10 normal cervical tissues were analyzed by immunohistochemistry for Lon protein levels. The expression of Lon was also examined by immunoblotting 16 fresh cervical cancer tissues and their respective non-tumor cervical tissues. In all cases, Lon expression was significantly elevated in cervical carcinomas as compared to normal tissues. Augmented Lon expression in tissue microarrays did not vary between age, tumor-node-metastasis grades, or lymph node metastasis. Knocking down Lon in HeLa cervical cancer cells by lentivrial transduction resulted in a substantial decrease in both mRNA and protein levels. Such down-regulation of Lon expression significantly blocked HeLa cell proliferation. In addition, knocking down Lon resulted in decreased cellular bioenergetics as determined by measuring aerobic respiration and glycolysis using the Seahorse XF24 extracellular flux analyzer. Together, these data demonstrate that Lon plays a potential role in the oncogenesis of cervical cancer, and may be a useful biomarker and target in the treatment of cervical cancer. Lon; immunohistochemistry; cervical cancer; cell proliferation; cellular bioenergetics.     

Cdk2 Silencing via a DNA/PCL Electrospun Scaffold Suppresses Proliferation and Increases Death of Breast Cancer Cells

RNA interference (RNAi) is a promising approach for cancer treatment. Site specific and controlled delivery of RNAi could be beneficial to the patient, while at the same time reducing undesirable off-target side effects. We utilized electrospinning to generate a biodegradable scaffold capable of incorporating and delivering a bioactive plasmid encoding for short hairpin (sh) RNA against the cell cycle specific protein, Cdk2. Three electrospun scaffolds were constructed, one using polycaprolactone (PCL) alone (Control) and PCL with plasmid DNA encoding for either Cdk2 (Cdk2i) and EGFP (EGFPi, also served as a control) shRNA. Scaffold fiber diameters ranged from 1 to 20 µm (DNA containing) and 0.2–3 µm (Control). While the electrospun fibers remained intact for more than two weeks in physiological buffer, degradation was visible during the third week of incubation. Approximately 20–60 ng/ml (∼2.5% cumulative release) of intact and bioactive plasmid DNA was released over 21 days. Further, Cdk2 mRNA expression in cells plated on the Cdk2i scaffold was decreased by ∼51% and 30%, in comparison with that of cells plated on Control or EGFPi scaffold, respectively. This decrease in Cdk2 mRNA by the Cdk2i scaffold translated to a ∼40% decrease in the proliferation of the breast cancer cell line, MCF-7, as well as the presence of increased number of dead cells. Taken together, these results represent the first successful demonstration of the delivery of bioactive RNAi-based plasmid DNA from an electrospun polymer scaffold, specifically, in disrupting cell cycle regulation and suppressing proliferation of cancer cells.     

Development and Validation of a Novel Platform-Independent Metastasis Signature in Human Breast Cancer

PurposeThe molecular drivers of metastasis in breast cancer are not well understood. Therefore, we sought to identify the biological processes underlying distant progression and define a prognostic signature for metastatic potential in breast cancer.ResultsWe identified a broad range of metastatic potential that was independent of intrinsic breast cancer subtypes. 146 genes were significantly associated with metastasis progression and were linked to cancer-related biological functions, including cell migration/adhesion, Jak-STAT, TGF-beta, and Wnt signaling. These genes were used to develop a platform-independent gene expression signature (M-Sig), which was trained and subsequently validated on 5 independent cohorts totaling nearly 1800 breast cancer patients with all p-values < 0.005 and hazard ratios ranging from approximately 2.5 to 3. On multivariate analysis accounting for standard clinicopathologic prognostic variables, M-Sig remained the strongest prognostic factor for metastatic progression, with p-values < 0.001 and hazard ratios > 2 in three different cohorts.ConclusionM-Sig is strongly prognostic for metastatic progression, and may provide clinical utility in combination with treatment prediction tools to better guide patient care. In addition, the platform-independent nature of the signature makes it an excellent research tool as it can be directly applied onto existing, and future, datasets.     

BMP9 Inhibits Proliferation and Metastasis of HER2-Positive SK-BR-3 Breast Cancer Cells through ERK1/2 and PI3K/AKT Pathways

Bone morphogenetic protein 9 (BMP9), a member of TGF-β superfamily, is reported to inhibit the growth and migration of prostate cancer, osteosarcoma and triple-negative MDA-MB-231 breast cancer cells. However, little is known about the effect of on the biological behaviors of HER2-positive SK-BR-3 breast cancer cells and the underlying mechanisms. This study aimed to investigate the effects of BMP9 on the proliferation and metastasis of SK-BR-3 cells with BMP9 over-expression or BMP9 down-regulated expression. Results indicated that exogenously expressed BMP9 inhibited the proliferation and metastasis of SK-BR-3 cells while decreased endogenous BMP9 expression in SK-BR-3 cells promoted the proliferation and migration of breast cancer cells in vitro and in vivo. In SK-BR-3 cells with BMP9 over-expression, the phosphorylation of HER2, ERK1/2 and AKT was markedly suppressed and the HER2 expression decreased at both mRNA and protein levels, while opposite results were observed in SK-BR-3 cells with BMP9 knock down. When the phosphorylation of ERK1/2 and PI3K/AKT was inhibited by PD98059 and {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002, respectively, the decreased proliferation and invasion induced by BMP9 knock down were eliminated. These findings suggest that BMP9 can inhibit the proliferation and metastasis of SK-BR-3 cells via inactivating ERK1/2 and PI3K/AKT signaling pathways. Thus, BMP9 may serve as a useful agent in the treatment of HER-2 positive breast cancer.     

MicroRNA-302a Suppresses Tumor Cell Proliferation by Inhibiting AKT in Prostate Cancer

Micro (mi) RNAs are important regulators involved in various physical and pathological processes, including cancer. The miRNA-302 family has been documented as playing a critical role in carcinogenesis. In this study, we investigated the role of miRNA-302a in prostate cancer (PCa). MiRNA-302a expression was detected in 44 PCa tissues and 10 normal prostate tissues, and their clinicopathological significance was analyzed. Cell proliferation and cell cycle analysis were performed on PCa cells that stably expressed miRNA-302a. The target gene of miRNA-302a and the downstream pathway were further investigated. Compared with normal prostate tissues, miRNA-302a expression was downregulated in PCa tissues, and was even lower in PCa tissues with a Gleason score ≥8. Overexpression of miRNA-302a induced G1/S cell cycle arrest in PCa cells, and suppressed PCa cell proliferation both in vitro and in vivo. Furthermore, miRNA-302a inhibits AKT expression by directly binding to its 3΄ untranslated region, resulting in subsequent alterations of the AKT-GSK3β-cyclin D1 and AKT-p27^Kip1 pathway. These results reveal miRNA-302a as a tumor suppressor in PCa, suggesting that miRNA-302a may be used as a potential target for therapeutic intervention in PCa.     

Rb Suppresses Collective Invasion,Circulation and Metastasis of Breast Cancer Cells in CD44-Dependent Manner

Basal-like breast carcinomas (BLCs) present with extratumoral lymphovascular invasion, are highly metastatic, presumably through a hematogenous route, have augmented expression of CD44 oncoprotein and relatively low levels of retinoblastoma (Rb) tumor suppressor. However, the causal relation among these features is not clear. Here, we show that Rb acts as a key suppressor of multiple stages of metastatic progression. Firstly, Rb suppresses collective cell migration (CCM) and CD44-dependent formation of F-actin positive protrusions in vitro and cell-cluster based lymphovascular invasion in vivo. Secondly, Rb inhibits the release of single cancer cells and cell clusters into the hematogenous circulation and subsequent metastatic growth in lungs. Finally, CD44 expression is required for collective motility and all subsequent stages of metastatic progression initiated by loss of Rb function. Altogether, our results suggest that Rb/CD44 pathway is a crucial regulator of CCM and metastatic progression of BLCs and a promising target for anti-BLCs therapy.     

依托咪酯通过调控miR-3666/UBQLN1基因表达抑制乳腺癌细胞增殖和诱导凋亡的机制

本研究旨在探讨依托咪酯对乳腺癌细胞增殖、凋亡的影响及其机制,选取依托咪酯(0.2μg/mL,0.4μg/mL和0.8μg/mL)处理乳腺癌细胞SK-BR-3,筛选最适浓度0.8μg/mL。将依托咪酯+anti-miR-NC组(转染anti-miR-NC)、依托咪酯+anti-miR-3666组(转染anti-miR-3666)、miR-NC组(转染miR-NC)、miR-3666组(转染anti-miR-3666)、anti-miR-NC组(转染anti-miR-NC)和anti-miR-3666组(转染anti-miR-3666)用脂质体法转染至SK-BR-3细胞,部分组用0.8μg/mL依托咪酯处理。细胞计数(CCK-8)法、流式细胞术、免疫印迹(Western blotting)、实时荧光定量逆转录聚合酶链反应(qRT-PCR)检测细胞的抑制率、凋亡率、miR-3666、泛素1(UBQLN1)、细胞周期素D1(CyclinD1)、细胞周期依赖性蛋白激酶抑制因子1A(p21)、B细胞淋巴瘤/白血病-2(Bcl-2)、Bcl-2相关的X基因(Bax)的表达;双荧光素酶报告基因检测实验检测细胞的荧光活性。依托咪酯(0.2μg/mL,0.4μg/mL和0.8μg/mL)明显的增强对乳腺癌细胞的抑制率和凋亡率,并上调miR-3666,下调UBQLN1,均呈明显的浓度依赖性(p<0.05)。miR-3666能够明显的抑制野生型UBQLN1细胞的荧光活性。过表达miR-3666具有与依托咪酯相似的增强乳腺癌细胞抑制率和凋亡率,下调CyclinD1、Bcl-2,上调p21、Bax的作用。抑制miR-3666明显的减弱依托咪酯对乳腺癌细胞的抑制和凋亡的作用。依托咪酯可抑制乳腺癌细胞增殖,促进凋亡,其机制与上调miR-3666进而靶向抑制UBQLN1有关,将可为依托咪酯用于乳腺癌的治疗提供更充分的理论依据。     

基于生物信息学分析研究miR-182-5p通过靶向调控EP300促进乳腺癌细胞的侵袭和转移

近期研究表明,miR-182-5p对多种癌症的侵袭和转移具有重要作用,但其在乳腺癌侵袭转移中的研究相对较少。本研究通过网上在线microRNA分析工具下载乳腺癌组织及正常乳腺组织表达比较的数据集,分析发现在GSE4589、GSE38167、GSE61438等3个数据库中,在乳腺癌组织中存在26个相同的microRNA,其中8个上调,而我们实验验证发现hsa-miR-182在8例病理组织中的表达上调差异最显著(P=0.001),选定目的基因hsa-miR-182;qRT-PCR检测细胞中miR-182-5p的表达,结果显示,与MCF-10A相比,miR-182-5p在MDA-MB-231、T47D、MDA-MB-453、MCF-7中表达上调(P<0.05);转染miR-182-5p干扰质粒,qRT-PCR检测细胞中miR-182-5p的表达情况。结果显示,miR-182-5p表达显著降低(P=0.003),提示转染成功;Transwell侵袭结果显示,MDAMB-231细胞敲低miR-182-5p,与对照组相比,体外侵袭能力明显降低(P=0.002);Western印迹检测转染miR-182-5p干扰质粒时,MDA-MB-231中上皮-间质转化(epithelial-mesenchymal transition,EMT)相关标志物的表达情况,结果显示,与对照组相比,敲低miR-182-5p使细胞中上皮-钙黏着蛋白(E-cadherin)表达上调,神经-钙黏着蛋白(N-cadherin)、波形蛋白(vimentin)表达下调。为研究探讨miR-182-5p的靶蛋白,采用在线预测软件预测可能与miR-182-5p结合的靶蛋白,cytoscape构建蛋白质互作网络图并筛选出hub基因;双荧光素酶结果证实,miR-182-5p可与EP300靶向结合(P=0.001);采用qRT-PCR、Western印迹检测转染miR-182-5p干扰质粒后EP300在mRNA及蛋白质水平的表达,结果显示,与对照组相比,在敲低miR-182-5p组中EP300在mRNA及蛋白质的表达上调(P=0.001)。综上所述,miR-182-5p可靶向调节EP300,促进乳腺癌细胞的侵袭与转移。     

miRNA-183 Suppresses Apoptosis and Promotes Proliferation in Esophageal Cancer by Targeting PDCD4

In our previous study, miRNA-183, a miRNA in the miR-96-182-183 cluster, was significantly over-expressed in esophageal squamous cell carcinoma (ESCC). In the present study, we explored the oncogenic roles of miR-183 in ESCC by gain and loss of function analysis in an esophageal cancer cell line (EC9706). Genome-wide mRNA microarray was applied to determine the genes that were regulated directly or indirectly by miR-183. 3′UTR luciferase reporter assay, RT-PCR, and Western blot were conducted to verify the target gene of miR-183. Cell culture results showed that miR-183 inhibited apoptosis (p < 0.05), enhanced cell proliferation (p < 0.05), and accelerated G1/S transition (p < 0.05). Moreover, the inhibitory effect of miR-183 on apoptosis was rescued when miR-183 was suppressed via miR-183 inhibitor (p < 0.05). Western blot analysis showed that the expression of programmed cell death 4 (PDCD4), which was predicted as the target gene of miR-183 by microarray profiling and bioinformatics predictions, decreased when miR-183 was over-expressed. The 3′UTR luciferase reporter assay confirmed that miR-183 directly regulated PDCD4 by binding to sequences in the 3′UTR of PDCD4. Pearson correlation analysis further confirmed the significant negative correlation between miR-183 and PDCD4 in both cell lines and in ESCC patients. Our data suggest that miR-183 might play an oncogenic role in ESCC by regulating PDCD4 expression.     

MiR-200a Suppresses the Proliferation and Metastasis in Pancreatic Ductal Adenocarcinoma through Downregulation of DEK Gene

MiR-200a has been reported to be able to suppress the epithelial-mesenchymal transition process in pancreatic cancer stem cells, suggesting that miR-200a could suppress the metastasis of pancreatic ductal adenocarcinoma (PDAC). However, its role in proliferation and metastasis of PDAC and the underlying mechanism by which miR-200a works in PDAC have not been elucidated. In our study, we for the first time identified that DEK gene is a direct downstream target of miR-200a. It was found that overexpression of miR-200a decreased DEK expression, suppressing the proliferation, migration, and invasion of PDAC cells. Meanwhile, knockdown of miR-200a can increase DEK level, promoting the proliferation, migration, and invasion of PDAC cells. Our study demonstrated that miR-200a suppresses the metastasis in pancreatic PDAC through downregulation of DEK, suggesting that miR-200a may be used as a novel potential marker in prediction of metastasis of PDAC.     

下调UCA1通过靶向miR-23b及其下游靶基因抑制胃癌细胞的增殖和转移

摘要 目的：探讨长链非编码RNA尿路上皮癌相关基因1（UCA1）调控胃癌细胞增殖和转移的分子机制。方法：将人胃癌细胞株SGC7901分为：对照组、siRNA-NC组、siRNA-UCA1组、inhibitor-NC组和miR-inhibitor组、si-UCA1+inhibitor-NC组和si-UCA1+miR-inhibitor组。对SGC7901细胞分别转染siRNA-UCA1及阴性对照（siRNA-NC）、miR-inhibitor及阴性对照（inhibitor-NC）,未转染的细胞作为对照组。通过RT-qPCR检测细胞中UCA1和miR-23b-3p的水平。通过CCK-8法、伤口愈合实验和Transwell实验评价细胞的增殖、迁移和侵袭能力。通过Western blot分析细胞中IL6R、BCL2和HSP90B1蛋白的表达。使用pcDNA-UCA1/pcDNA-NC与pGL3-miR-23b-3p-WT/pGL3-miR-23b-3p-Mut共转染细胞,通过双荧光素酶报告实验验证UCA1与miR-23b-3p的靶向关系。结果：细胞培养48 h和72 h后,与对照组比较,siRNA-UCA1组的细胞活力分别降低了31.58%和31.40%（P<0.05）。与对照组比较,siRNA-UCA1组的细胞迁移率[(61.46±5.43)% vs (23.16±3.17)%]、侵袭细胞数量（109.17±9.66 vs 50.83±6.96）、IL6R、BCL2和HSP90B1的蛋白相对表达量均显著降低,而miR-23b-3p相对表达量升高（P<0.05）。与pGL3-miR-23b-3p-WT共转染后,与pcDNA-NC组比较,pcDNA-UCA1组的相对荧光酶活性降低了66.12%（P<0.05）。与si-UCA1+inhibitor-NC组比较,si-UCA1+miR-inhibitor组的细胞活力、细胞迁移率、侵袭细胞数量、IL6R、BCL2和HSP90B1的蛋白相对表达量均显著升高（P<0.05）。结论：下调UCA1通过靶向miR-23b-3p及其下游基因IL6R、BCL2和HSP90B1来抑制胃癌细胞的增殖和转移。