Effects of ARHI on breast cancer cell biological behavior regulated by microRNA-221

The aplysia ras homolog member I (ARHI) is a tumor suppressor gene and is downregulated in various cancers. The downregulation of ARHI was regulated by miR-221 in prostate cancer cell lines. However, it has not been reported whether ARHI is regulated by miR-221 in breast cancer. Here, we reported that the ARHI protein level was downregulated in breast cancer tissues and breast cancer cell lines. The overexpression of ARHI could inhibit cell proliferation and invasion and induce cell apoptosis. To address whether ARHI is regulated by miR-221 in breast cancer cell lines, the results in this study showed that a significant inverse correlation existed between ARHI and miR-221. MiR-221 displayed an upregulation in breast cancer tissues and breast cancer cell lines. The inhibition of miR-221 induced a significant upregulation of ARHI in MCF-7 cells. To prove a direct interaction between miR-221 and ARHI mRNA, ARHI 3′UTR, which includes the potential target site for miR-221, was cloned downstream of the luciferase reporter gene of the pMIR-REPORT vector to generate the pMIR-ARHI-3′UTR vector. The results confirmed a direct interaction of miR-221 with a target site on the 3′UTR of ARHI. In conclusion, ARHI is a tumor suppressor gene that is downregulated in breast cancer. The overexpression of ARHI could inhibit breast cancer cell proliferation and invasion and induce cell apoptosis. This study demonstrated for the first time that the downregulation of ARHI in breast cancer cells could be regulated by miR-221.     

miR-615 Inhibits Prostate Cancer Cell Proliferation and Invasion by Directly Targeting Cyclin D2

Previous studies have reported that miR-615 exerts a tumor suppressor role in some tumors, such as esophageal squamous cell carcinoma and non-small cell lung cancer. However, the role of miR-615 in prostate cancer has not been defined. Here we found that miR-615 was downregulated in prostate cancer tissues and cell lines. Overexpression of miR-615 in PC-3 cells significantly inhibited cellular proliferation, migration, and invasion. Moreover, overexpression of miR-615 delayed tumor growth in vivo. In terms of mechanism, we found that cyclin D2 (CCND2) is a target gene of miR-615 in prostate cancer. We showed that miR-615 could bind to the 3 -UTR region of CCND2 mRNA and inhibit its expression. There was a negative correlation between the expression of miR-615 and CCND2 in prostate cancer tissues. Moreover, restoration of cyclin D2 abolished the inhibitory effects of miR-615 on the proliferation, migration, and invasion of prostate cancer cells. Taken together, our study identified miR-615 as a tumor suppressor by targeting cyclin D2 in prostate cancer.     

miR-613通过下调Wnt/β-catenin信号通路活性抑制前列腺癌细胞的增殖与侵袭

目的:研究miR-613在人前列腺癌组织中的表达情况,探讨miR-613是否通过下调Wnt信号通路活性抑制前列腺癌细胞系细胞的增殖和侵袭能力。方法:收集临床前列腺癌组织及配对癌旁组织20例,通过实时荧光定量PCR(RT-qPCR)检测各组组织中miR-613的表达情况。进一步在细胞实验中,通过转染miR-613 mimic和miR-NC至离体培养的PC-3、DU-145细胞中,随后,采用MTT法、平板克隆实验检测细胞增殖和Matrigel侵袭实验测定前列腺癌细胞的侵袭情况,采用荧光素酶分析方法评估Wnt信号通路活性变化,采用实时荧光定量PCR(RT-qPCR)检测Wnt/β-catenin信号通路下游靶基因的转录(包括Cyclin D1和c-Myc),WB法检测细胞中β-catenin、c-Myc和Cyclin D1的表达量。结果:相比配对癌旁组织,miR-613在前列腺癌组织中的表达降低(P<0.01);在体外细胞实验中,相比于miR-NC组,转染miR-613 mimic后,PC-3、DU-145细胞增殖能力下降(P<0.05),PC-3、DU-145细胞的迁移侵袭能力下降(P<0.01);miR-613的过表达显著降低Wnt信号通路活性、β-catenin蛋白表达及Wnt信号下游靶基因Cyclin D1和c-Myc的转录及蛋白表达。结论:miR-613通过抑制Wnt/β-catenin信号通路来影响前列腺癌细胞的增殖与侵袭,为前列腺癌的潜在治疗靶点之一。     

miR-181b在前列腺组织中的表达及对前列腺癌细胞PC-3生物学功能的影响

目的：探讨miR-181b在前列腺癌组织中的表达及miR-181b对前列腺癌PC-3细胞生物学功能的影响。方法：收集27例前列腺癌手术标本及30例正常前列腺组织标本,提取总微小RNA,应用实时荧光定量PCR技术检测miR-181b的表达情况。选取人前列腺癌细胞株PC-3细胞为研究对象,转染miR-181b ASO。应用实时荧光定量PCR技术检测转染miR-181b ASO PC-3细胞中miR-181b的表达情况;流式细胞术检测转染miR-181b ASO PC-3细胞的凋亡变化情况;MTT实验及细胞生长曲线检测转染miR-181b ASO PC-3细胞增殖能力的影响;Transwell侵袭实验检测转染miR-181b ASO PC-3细胞侵袭能力的影响。结果：miR-181b在前列腺癌组织中高表达。转染miR-181b ASO使PC-3细胞中miR-181b的表达降低;促进了PC-3细胞凋亡;miR-181b的表达降低导致前列腺癌细胞株PC-3增殖能力的减弱;miR-181b的表达降低导致前列腺癌细胞PC-3侵袭能力减弱。结论：miR-181b在前列腺癌组织中高表达,封闭前列腺癌细胞中miR-181b的表达,可以促进细胞凋亡及抑制细胞的增殖及侵袭,可能在前列腺肿瘤的基因治疗中起到积极作用。     

MicroRNA expression signature of castration-resistant prostate cancer: the microRNA-221/222 cluster functions as a tumour suppressor and disease progression marker

Background:

Our present study of the microRNA (miRNA) expression signature in castration-resistant prostate cancer (CRPC) revealed that the clustered miRNAs microRNA-221 (miR-221) and microRNA-222 (miR-222) are significantly downregulated in cancer tissues. The aim of this study was to investigate the functional roles of miR-221 and miR-222 in prostate cancer (PCa) cells.

Methods:

A CRPC miRNA signature was constructed by PCR-based array methods. Functional studies of differentially expressed miRNAs were analysed using PCa cells. The association between miRNA expression and overall survival was estimated by the Kaplan–Meier method. In silico database and genome-wide gene expression analyses were performed to identify molecular targets regulated by the miR-221/222 cluster.

Results:

miR-221 and miR-222 were significantly downregulated in PCa and CRPC specimens. Kaplan–Meier survival curves showed that low expression of miR-222 predicted a short duration of progression to CRPC. Restoration of miR-221 or miR-222 in cancer cells revealed that both miRNAs significantly inhibited cancer cell migration and invasion. Ecm29 was directly regulated by the miR-221/222 cluster in PCa cells.

Conclusions:

Loss of the tumour-suppressive miR-221/222 cluster enhanced migration and invasion in PCa cells. Our data describing targets regulated by the tumour-suppressive miR-221/222 cluster provide insights into the mechanisms of PCa and CRPC progression.     

PUMA is a novel target of miR-221/222 in human epithelial cancers

miR-221 and miR-222 (miR-221/222) are frequently up-regulated in human epithelial cancers. However, the mechanism of miR-221/222 action involved in carcinogenesis has not been extensively studied. Here, we found that reduction of miR-221/222 inhibited cell proliferation and induced mitochondrial-mediated apoptosis in human epithelial cancer cells (A549 lung cancer and MCF-7 breast cancer cells). Bioinformatics and luciferase reporter assays showed that miR-221/222 co-modulated the p53 upregulated modulator of apoptosis (PUMA) expression by directly targeting the binding site within the 3'UTR. Together, these findings suggest that PUMA is a direct target of miR-221/222 that functions as an endogenous apoptosis regulator in these epithelial cancers.     

miR-221/222 induces pancreatic cancer progression through the regulation of matrix metalloproteinases

MicroRNAs are involved in the initiation and progression of pancreatic cancer. In this study, we showed that miR-221/222 is overexpressed in pancreatic cancer. MiR-221/222 overexpression significantly promoted pancreatic cancer cell proliferation and invasion while inhibiting apoptosis. The expression of the matrix metalloproteinases (MMPs) MMP-2 and MMP-9 was increased in miR-221/222 mimic-transfected pancreatic cancer cells. Validation experiments identified TIMP-2 as a direct target of miR-221/222. These data indicate that overexpressed miR-221/222 may play an oncogenic role in pancreatic cancer by inducing the expression of MMP-2 and MMP-9, thus leading to cancer cell invasion.     

MiR-221/-222 differentiate prognostic groups in advanced breast cancers and influence cell invasion

Background:

MiR-221/-222 are frequently overexpressed in breast cancer and are associated with increased malignancy. The specific modification of microRNAs (miRNAs) expression could be a promising strategy in breast cancer therapy, leading to the suppression of tumourigenic processes in tumour cells.

Methods:

MiR-221/-222 expressions were analysed in 86 breast cancer tissues by quantitative RT–PCR and tested for correlation with immunohistochemistry data and clinical follow-up. In vitro assays were conducted using human breast cancer cell lines with lentiviral overexpression of miR-221/-222.

Results:

In tumour tissues, miR-221/-222 were associated with the occurrence of distant metastases. In particular, high levels of miR-221 were revealed to have a high prognostic impact for the identification of significantly different groups with advanced tumours. MiR-221/-222 overexpression strongly increased cell proliferation and invasion in vitro. Following miR-221/-222 overexpression an increased uPAR expression and cell invasion were observed.

Conclusion:

This study demonstrates a significant role for highly expressed miR-221/-222 in advanced breast cancers allowing for the identification of significantly different prognostic groups, particularly for HER2-positive and lymph-node-positive breast cancers. Considering that miR-221/-222 are strongly involved in cell invasion, these miRNAs may be promising markers for breast cancer prognosis and therapy.     

miR-221/222 is the regulator of Cx43 expression in human glioblastoma cells

The miR-221/222 cluster is significantly upregulated in malignant glioma cells and regulates the expression of multiple genes associated with glioma cell proliferation, invasion and apoptosis, which was shown in our previous studies. Cx43 has been identified as a tumor suppressor and major component for the establishment of gap junction intercellular communication (GJIC) in glial cells, which is frequently reduced or deleted in high-grade gliomas. According to bioinformatic analysis, connexin 43 (Cx43) may be one of the target genes of miR-221/222. The aim of the present study was to validate Cx43 as a target gene of miR-221/222 and to determine whether overexpression of miR-221/222 is one of the molecular mechanisms for the reduced expression of Cx43 in malignant gliomas. We transfected miR-221/222 antisense oligonucleotides (AS-miR-221/222) into U251 human glioblastoma cells using a lipofectamine method. Northern blot analysis was conducted to detect the expression of the miR-221/222 cluster. Luciferase reporter assays were exploited to confirm Cx43 as a target gene of miR-221/222. Cx43 expression was assessed by western blotting and immunofluorescence staining. Scrape loading and dye transfer (SLDT) assays were used for examination of GJIC. Proliferation and invasion of U251 cells were evaluated by MTT and transwell assays, respectively. Cell cycle kinetics and apoptosis were determined with flow cytometry. We found that expression of the miR-221/222 cluster was significantly reduced while Cx43 expression was upregulated in U251 cells transfected with AS-miR-221/222, and the GJIC deficiency in parental U251 cells was re-established. Moreover, the luciferase activity determined by the luciferase reporter assay was enhanced in AS-miR-221/222-treated cells, and cell proliferation and invasion were suppressed while apoptosis was induced. We conclude that miR-221/222 function as oncogenic microRNAs in human gliomas, at least in part, by targeting Cx43.     

乳腺癌中miR-221、miR-222表达水平对GATA3和FOXA1蛋白的影响及其作用机制

目的： 探讨乳腺癌中miR-221和miR-222（miR-221/222）表达水平对GATA结合蛋白3（GATA3）和叉头框蛋白A1（FOXA1）表达的影响及其作用机制。方法： 收集汕头大学医学院附属肿瘤医院2020年1月—2021年5月经手术切除的86例乳腺浸润性导管癌及其癌旁组织标本,分别采用茎环引物实时荧光定量PCR（qPCR）和免疫组织化学方法检测癌组织和相应癌旁组织中miR-221/222的表达水平及GATA3、FOXA1蛋白的表达水平,分析其与临床病理指标的关系。进一步在5种乳腺癌细胞系（MCF-7、T47D、SKBR3、MDA-MB-231和BT-549）中转染miR-221/222 mimics后,采用qPCR检测各细胞中miR-221/222的表达水平;采用Western blot检测转染后MCF-7细胞中GATA3、FOXA1、雌激素受体-α（ER-α）和钙黏蛋白E（E-cadherin）的表达;用细胞划痕和迁移侵袭实验检测转染后MCF-7细胞修复和迁移侵袭能力。结果： 在乳腺癌组织中,miR-221/222的表达水平明显高于癌旁正常乳腺组织（P=0.00）。miR-221/222表达水平在FOXA1、GATA3、ER-α及孕激素受体（PR）阴性表达组均显著高于阳性表达组（P<0.01）;在Her-2阳性和高表达Ki-67的乳腺癌中较Her-2阴性和低表达Ki-67组显著升高（P<0.05）;在三阴性和Her-2阳性亚型乳腺癌中显著高于Luminal A和Luminal B1型乳腺癌（P=0.00）;而miR-221/222水平与患者年龄、月经状况、肿瘤大小、组织学分级、淋巴结转移及TNM分期无显著相关关系（P>0.05）。在5种乳腺癌细胞系中,miR-221/222在MCF-7细胞中均低表达。与对照组相比,在MCF-7细胞中瞬时转染miR-221/222 mimics后miR-221/222表达显著升高（P<0.05）,且内源性的GATA3和FOXA1蛋白表达被抑制（P<0.01）,上皮细胞相关分子ER-α和E-cadherin表达显著下降（P<0.01）;划痕修复能力和迁移侵袭能力均显著增强（P<0.01）。结论： miR-221/222可能通过下调GATA3和FOXA1的表达促进乳腺癌的迁移和侵袭。     

lncRNA FLJ26245通过miR-200a-3p/PTPRG轴调控前列腺癌PC-3细胞的增殖与迁移

目的:探讨lncRNA FLJ26245在前列腺癌组织和细胞中的表达及其对PC-3细胞增殖与迁移能力的影响及其分子机制.方法:选用2017年3月至2019年5月在洛阳中心医院手术切除的52例前列腺癌及相应的癌旁组织标本,以及前列腺细胞系LNCaP、C4-2B、PC-3、DU-145和正常前列腺上皮细胞RWPE-1,用q...     

miR-30c Impedes Glioblastoma Cell Proliferation and Migration by Targeting SOX9

miR-30c has been acknowledged as a tumor suppressor in various human cancers, such as ovarian cancer, gastric cancer, and prostate cancer. However, the role of miR-30c in glioblastoma (GBM) needs to be investigated. In our study, we found that the expression of miR-30c was significantly downregulated in GBM tissues and cell lines. We found that overexpression of miR-30c inhibited cellular proliferation of GBM cells in vitro and in vivo. More GBM cells were arrested in the G₀ phase after miR-30c overexpression. Moreover, we showed that miR-30c overexpression suppressed the migration and invasion of GBM cells. Mechanistically, we found that SOX9 was a direct target of miR-30c in GBM cells. Overexpression of miR-30c inhibited the mRNA and protein levels of SOX9 in GBM cells. Moreover, there was a negative correlation between the expression of miR-30c and SOX9 in GBM tissues. Finally, we showed that restoration of SOX9 in GBM cells reversed the proliferation, migration, and invasion of GBM cells transfected with miR-30c mimic. Collectively, our results demonstrated that miR-30c suppressed the proliferation, migration, and invasion of GBM cells via targeting SOX9.     

MicroRNA-221 and microRNA-222 regulate gastric carcinoma cell proliferation and radioresistance by targeting PTEN

Background  

MicroRNAs (miRNAs) can function as either oncogenes or tumor suppressor genes via regulation of cell proliferation and/or apoptosis. MiR-221 and miR-222 were discovered to induce cell growth and cell cycle progression via direct targeting of p27 and p57 in various human malignancies. However, the roles of miR-221 and miR-222 have not been reported in human gastric cancer. In this study, we examined the impact of miR-221 and miR-222 on human gastric cancer cells, and identified target genes for miR-221 and miR-222 that might mediate their biology.     

lncRNA GTSE1-AS1在前列腺癌组织中的表达及其对LNCaP细胞增殖与侵袭的影响

目的:探讨长链非编码RNA(long non-coding RNA,lncRNA)GTSE1-AS1在前列腺癌组织中的表达及其影响LNCaP细胞增殖和侵袭的机制.方法:收集2017年11月至2018年12月郑州大学附属洛阳中心医院泌尿外科手术切除的68例前列腺癌患者的癌和癌旁组织标本,以及前列腺癌细胞系LNCaP、PC...     

反义microRNA-221与反义microRNA-222抑制人脑胶质瘤细胞的体外与体内生长

目的 探讨敲低microRNA(miR)-221和miR-222表达以抑制人脑胶质瘤U251细胞生长的作用及其机制.方法 脂质体介导转染反义寡聚核苷酸(AS-miR-221和AS-miR-222)于人脑胶质瘤细胞U251.采用Northern blot鉴定转染后U251细胞的miR-221和miR-222表达水平;四甲基偶氮唑蓝(MTT)法评价AS-miR-221和AS-miR-222抑制U251细胞生长的作用;Transwell实验检测细胞侵袭能力;流式细胞术检测细胞周期的分布和凋亡;Western blot检测转染后U251细胞相关蛋白表达的变化,并用AS-miR-221和AS-miR-222治疗裸鼠皮下移植瘤,观察其在活体内对肿瘤生长的抑制作用.结果 Northern blot检测结果 显示,AS-miR-221和AS-miR-222共转染后,肿瘤细胞miR-221和miR-222表达明显下降,细胞生长速度降低,细胞穿过率为14.5%,细胞周期出现G0/G1期阻滞,凋亡率(13.7%)增高,并可见connexin43、p27、PUMA、caspase-3、PTEN、TIMP3和Bax等相关蛋白表达增高,而bcl-2表达降低,p53无明显变化.经AS-miR-221和AS-miR-222治疗后,裸鼠皮下移植瘤生长明显受抑.结论 AS-miR-221和AS-miR-222共转染可抑制U251细胞的增殖与侵袭,miR-221和miR-222可以作为人脑胶质瘤基因治疗的侯选靶点.     

miR-132 Targets FOXA1 and Exerts Tumor-Suppressing Functions in Thyroid Cancer

MicroRNA-132 (miR-132) has been demonstrated to be a tumor suppressor in several types of tumors. However, the expression and the role of miR-132 in human thyroid cancer are still poorly understood. The aim of the present study was to examine the potential roles and molecular mechanism of miR-132 in thyroid cancer. We found that miR-132 expression levels were significantly downregulated in thyroid cancer tissues and cell lines. Function assays showed that overexpression of miR-132 in TPC1 cells inhibited cell proliferation, migration, and invasion. Forkhead box protein A1 (FOXA1) was identified as a direct target of miR-132 in thyroid cancer cells. Knockdown of FOXA1 in TPC1 cells significantly inhibited cell proliferation, migration, and invasion, which mimicked the suppressive effect induced by miR-132 overexpression. Restoration of FOXA1 expression partially reversed the suppressive effect induced by miR-132 overexpression. Taken together, these results suggested that miR-132 acts as a tumor suppressor in thyroid cancer through targeting FOXA1.     

MicroRNA-145 is regulated by DNA methylation and p53 gene mutation in prostate cancer

MiR-145 is downregulated in various cancers including prostate cancer. However, the underlying mechanisms of miR-145 downregulation are not fully understood. Here, we reported that miR-145 was silenced through DNA hypermethylation and p53 mutation status in laser capture microdissected (LCM) prostate cancer and matched adjacent normal tissues. In 22 of 27 (81%) prostate tissues, miR-145 was significantly downregulated in the cancer compared with the normal tissues. Further studies on miR-145 downregulation mechanism showed that miR-145 is methylated at the promoter region in both prostate cancer tissues and 50 different types of cancer cell lines. In seven cancer cell lines with miR-145 hypermethylation, 5-aza-2'-deoxycytidine treatment dramatically induced miR-145 expression. Interestingly, we also found a significant correlation between miR-145 expression and the status of p53 gene in both LCM prostate tissues and 47 cancer cell lines. In 29 cell lines with mutant p53, miR-145 levels were downregulated in 28 lines (97%), whereas in 18 cell lines with wild-type p53 (WT p53), miR-145 levels were downregulated in only 6 lines (33%, P < 0.001). Electrophoretic mobility shift assay showed that p53 binds to the p53 response element upstream of miR-145, but the binding was inhibited by hypermethylation. To further confirm that p53 binding to miR-145 could regulate miR-145 expression, we transfected WT p53 and MUT p53 into PC-3 cells and found that miR-145 is upregulated by WT p53 but not with MUTp53. The apoptotic cells are increased after WT p53 transfection. In summary, this is the first report documenting that downregulation of miR-145 is through DNA methylation and p53 mutation pathways in prostate cancer.     

miR-132 Targets FOXA1 and Exerts Tumor-Suppressing Functions in Thyroid Cancer

MicroRNA-132 (miR-132) has been demonstrated to be a tumor suppressor in several types of tumors. However, the expression and the role of miR-132 in human thyroid cancer are still poorly understood. The aim of the present study was to examine the potential roles and molecular mechanism of miR-132 in thyroid cancer. We found that miR-132 expression levels were significantly downregulated in thyroid cancer tissues and cell lines. Function assays showed that overexpression of miR-132 in TPC1 cells inhibited cell proliferation, migration, and invasion. Forkhead box protein A1 (FOXA1) was identified as a direct target of miR-132 in thyroid cancer cells. Knockdown of FOXA1 in TPC1 cells significantly inhibited cell proliferation, migration, and invasion, which mimicked the suppressive effect induced by miR-132 overexpression. Restoration of FOXA1 expression partially reversed the suppressive effect induced by miR-132 overexpression. Taken together, these results suggested that miR-132 acts as a tumor suppressor in thyroid cancer through targeting FOXA1.     

肿瘤转移抑制基因1抑制前列腺癌细胞的增殖和侵袭能力

目的 研究肿瘤转移抑制基因1(TMSG-1)转染对高转移人前列腺癌细胞体外增殖能力和侵袭能力的影响.方法 将TMSG-1全长真核表达载体稳定转染人前列腺癌细胞高转移亚系PC-3M-1E8,G418筛选,逆转录聚合酶链反应(RT-PCR)和Western blot方法选取TMSG-1过表达阳性克隆.通过活细胞计数、二苯基溴化四氮唑蓝(MTF)比色实验、软琼脂集落形成实验检测体外细胞生长能力;Matrigel穿膜实验检测肿瘤细胞体外侵袭能力.结果 在稳定转染TMSG-1基因的PC-3M-1E8细胞系中,筛选出3株TMSG-1转录活性及蛋白表达水平均明显升高的细胞用于后续生物学行为实验.活细胞计数和MTT比色实验结果显示,从计数第3天起,与空载体对照组和空白对照组相比,3株正义转染组细胞生长速度均明显减慢(P<0.05).软琼脂集落形成实验结果显示,3株正义转染组的细胞软琼脂集落形成数与空载体对照组、空白对照组相比,均明显减少(P<0.05),分别为26.00±3.21、13.33±1.45和32.83±2.18.Matrigel穿膜实验结果显示,正义转染的各组细胞与空载体对照组及空白对照组相比,穿膜细胞数均明显减少(P<0.05),分别为45.33±4.16、54.00±2.83和26.33±3.79.结论 TMSG-1表达上调可使高转移人前列腺癌细胞体外增殖速度、锚着不依赖性生长能力及侵袭能力明显降低,TMSG-1可能通过抑制肿瘤细胞生长和侵袭抑制肿瘤转移潜能.