The Significance of miR-34a Expression in Endometrial Carcinogenesis: Correlation With Expression of p16 and Ki-67 Proteins in Endometrial Cancers

Yoon Sung Choi,Kyung Eun Lee 대한암예방학회 2015 Journal of cancer prevention Vol.20 No.4

Background: A microRNA, miR-34a, plays a key role in inhibiting cellular transformation and carcinogenesis by controlling cell cycle regulation and cell proliferation in various human tumors. However, miR-34a has rarely been reported in endometrial cancer research in Korea. This study was undertaken to analyze miR-34a expression in simple endometrial hyperplasia and endometrial cancer, and to evaluate the relationship between expression of miR-34a and p16 and Ki-67 proteins in endometrial cancers. Methods: A retrospective study was carried out on 66 formalin-fixed, paraffin-embedded tissues with simple endometrial hyperplasia (31 cases) and endometrial cancer (35 cases) patients. These were analyzed for miR-34a expression by quantitative real-time PCR , and the expression of p16 and Ki-67 proteins in endometrial cancers was evaluated by immunohistochemistry. Results: The miR-34a expression level was lower in endometrial cancer tissues (−0.71 ± 3.90) than in simple endometrial hyperplasia tissues (2.68 ± 8.62). The endometrial hyperplasia tissues showed underexpression of miR-34a in 13 of the 31 cases (41.9%) while the endometrial cancer tissues showed underexpression of miR-34a in 24 of 35 cases (68.6%). Thus, miR-34a was significantly underexpressed in endometrial cancer tissues when compared endometrial hyperplasia tissues (P = 0.046). Overexpression of p16 was detected in 25 (71.4%) and Ki-67 immunoreactivity was detected in 27 (77.1%) of the 35 endometrial cancers. Although not statistically significant, the frequency of p16 and Ki-67 overexpression tended to be lower in the cases with miR-34a underexpression than in cases with miR-34a overexpression. Conclusions: These findings suggest that underexpression of miR-34a might be involved in endometrial carcinogenesis. Further studies are needed to define the relationship between miR-34a expression and tissue specific protein expression.

miR-34a Inhibitor May Effectively Protect against Sevoflurane-Induced Hippocampal Apoptosis through the Wnt/β-Catenin Pathway by Targeting Wnt1

Xiaoling Zhao,Yue Sun,Yongbo Ding,Jun Zhang,Kezhong Li 연세대학교의과대학 2018 Yonsei medical journal Vol.59 No.10

Purpose: Research has shown that sevoflurane-induced toxicity causes neurodegeneration in the developing brain. miR-34a has been found to negatively regulate ketamine-induced hippocampal apoptosis and memory impairment. However, the role of miR-34a in sevoflurane-induced hippocampal neurodegeneration remains largely unclear. Materials and Methods: C57/BL6 mice (7-day-old) inhaled 2.3% sevoflurane for 2 h/day over 3 consecutive days. miR-34a expressionwas reduced through intracerebroventricular injection with miR-34a interference lentivirus vector (LV-anti-miR-34a) into mouse hippocampus after anesthesia on the first day of exposure. Hippocampal apoptosis was detected by TUNEL assay and flow cytometry analysis. Spatial memory ability was evaluated by the Morris water maze test. The interaction between miR-34a and Wnt1 was confirmed by luciferase reporter assay, RNA immunoprecipitation, Western blot, and immunofluorescence staining. The effects of miR-34a on protein levels of B-cell lymphoma 2 (Bcl-2), bcl-2-like protein 4 (Bax), and Wnt/β-catenin pathway-related proteins were evaluated using Western blot analysis. Results: Sevoflurane upregulated hippocampal miR-34a, and miR-34a inhibitor attenuated sevoflurane-induced hippocampal apoptosis and memory impairment. miR-34a negatively regulated Wnt1 expression by targeting miR-34a in hippocampal neurons. Moreover, forced expression of Wnt1 markedly undermined miR-34a-mediated enhancement of sevoflurane-induced apoptosis of hippocampal neurons, while Wnt1 silencing greatly restored anti-miR-34a-mediated repression of sevoflurane-inducedapoptosis of hippocampal neurons. Increased expression of miR-34a inhibited the Wnt/β-catenin pathway in hippocampalneurons exposed to sevoflurane, while anti-miR-34a exerted the opposite effects. Conclusion: miR-34a inhibitor may effectively protect against sevoflurane-induced hippocampal apoptosis via activation of the Wnt/β-catenin pathway by targeting Wnt1.

MicroRNA-34a inhibits cell invasion and epithelial-mesenchymal transition via targeting AXL/PI3K/AKT/Snail signaling in nasopharyngeal carcinoma

Chengyi Jiang,Zhongqiang Cheng,Tao Jiang,Yajia Xu,Bin Wang 한국유전학회 2020 Genes & Genomics Vol.42 No.8

Background MicroRNA-34a (miR-34a) has been reported to inhibit TGF-β (transforming growth factor-β)-induced epithelialmesenchymal transition (EMT) in nasopharyngeal carcinoma (NPC). However, the underlying mechanism remain unclear. Using the bioinformatics, we found that the AXL receptor tyrosine kinase (AXL) is a predicted target of miR-34a. Objective we aimed to reveal the relationship between miR-34a and AXL, and investigate the effect and mechanism of miR-34a in NPC progression. Methods The expression patterns of miR-34a and AXL in 30 paired NPC tissues and the adjacent tissues were examined by quantitative real time PCR (qRT-PCR). The target relationship between miR-34a and AXL was evaluated by the luciferase gene reporter assay. Cell migration and invasion were assessed by wound healing and transwell chamber assays, respectively. Results miR-34a level was dramatically decreased in the NPC tissues compared to the adjacent tissues, while AXL expression was increased. Overexpression of miR-34a significantly reduced the luciferase activity of the luciferase vector of AXL (pGL3-AXL-WT), whereas this effect was abrogated when binding sites between miR-34a and AXL were mutated. In addition, ectopic expression of miR-34a dramatically inhibited Sune-1 cell migration and invasion abilities, decreased the levels of N-cadherin and Vimentin and increased E-cadherin and γ-catenin expressions, as well as induced significant reductions in the expressions of p-AKT and Snail. However, these effects were attenuated when the cells were treated with recombinant human AXL protein. Conclusions Our results demonstrate that miR-34a/AXL can inhibit NPC cell migration, invasion and EMT through inhibition of AKT/Snail signaling.

Down-regulation of miR-34a Expression in Cervical Intraepithelial Neoplasia with Human Papillomavirus Infection and Its Relationship with p53 Expression

Kyung Eun Lee 대한의생명과학회 2013 Biomedical Science Letters Vol.19 No.4

microRNAs (miRNAs) play pivotal roles in controlling cell proliferation and differentiation. miRNA expression in human is becoming recognized as a new molecular mechanism of carcinogenesis. microRNA-34a (miR-34a), a member of the p53 network, was found to be regulated in multiple types of tumor. The purpose of this study was to define roles of miR-34a expression in cervical intraepithelial neoplasia with human papillomavirus infection, and its relationship with p53 protein expression. This study was performed to analyze expression of miR-34a by using qRT-PCR, and to evaluate p53 protein expression by using immunohistochemistry in 40 cases. Down-regulation of miR-34a expression was detected in 27 (67.5%) out of 40 cases and Immunoreactivity for p53 was found in 17 (42.5%) out of 40 cases. Nineteen (82.6%) of the 23 cases with a negative p53 expression showed a down-regulation miR-34a expression, there was a significant associations between miR-34a and p53 protein expression (P=0.04). These results suggest that miRNA-34a expression tend to be reduced depending on the advanced histologic grade, and down-regulation of miR-34a expression might be associated with inactivation of p53 protein expression by human papillomavirus infection.

Nanovesicle-mediated systemic delivery of microRNA-34a for CD44 overexpressing gastric cancer stem cell therapy

Jang, Eunji,Kim, Eunjung,Son, Hye-Young,Lim, Eun-Kyung,Lee, Hwunjae,Choi, Yuna,Park, Kwangyeol,Han, Seungmin,Suh, Jin-Suck,Huh, Yong-Min,Haam, Seungjoo Elsevier 2016 Biomaterials Vol.105 No.-

<P><B>Abstract</B></P> <P>The cancer stem cell (CSC) hypothesis postulates that cancer cells overexpressing CD44 are marked as CSCs that cause tumorigenesis and recurrence. This hypothesis suggests that CD44 is a potential therapeutic target that can interfere with CSCs qualities. MicroRNA-34a (miR-34a) is a promising candidate for CD44 repression-based cancer therapy as it has been reported to inhibit proliferation, metastasis, and survival of CD44-positive CSCs. Here, we used nanovesicles containing PLI/miR complexes (NVs/miR) to systemically deliver miR-34a and induce miR-34a-triggered CD44 suppression in orthotopically and subcutaneously implanted tumors in nude mice. Poly(<SMALL>L</SMALL>-lysine-graft-imidazole) (PLI) condenses miRs and is functionally modified to deliver miRs to the site of action by buffering effect of imidazole residues under endosomal pH. Indeed, NVs/miR consisting of PEGylated lipids enveloping PLI/miR complexes greatly reduced inevitable toxicity of polycations by compensating their surface charge and markedly improved their <I>in vivo</I> stability and accumulation to tumor tissue compared to PLI/miR polyplexes. Our NVs-mediated miR-34a delivery system specifically increased endogenous target miR levels, thereby attenuating proliferation and migration of gastric cancer cells by repressing the expression of CD44 with decreased levels of Bcl-2, Oct 3/4 and Nanog genes. Our strategy led to a greater therapeutic outcome than PLI-based delivery with highly selective tumor cell death and significantly delayed tumor growth in CD44-positive tumor-bearing mouse models, thus providing a fundamental therapeutic window for CSCs.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Micro RNA 34a and Let-7a Expression in Human Breast Cancers is Associated with Apoptotic Expression Genes

Behzad, Mansoori,Ali, Mohammadi,Solmaz, Shirjang,Elham, Baghbani,Behzad, Baradaran Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.4

Breast cancer is the most common cause of cancer-related death among women in the whole world. MiR- 34a and let-7a are well known tumor suppressors that participate in the regulation of apoptosis, invasion and other cellular functions. In this study, expression of miR-34a, let-7a and apoptosis pathway genes such as Bcl-2, Caspase-3 and P53 were evaluated using quantitative real-time PCR in 45 paired samples of normal margin and tumor tissue collected from breast cancer patient at advanced stage (3-4). MiR-34a, let-7a, caspase-3 and P53 expression are reduced and Bcl-2 expression is increased within tumoral tissues in comparison with normal margin tissues. P53 expression directly or indirectly was correlated with miR-34a, let-7a, Bcl-2 and caspase-3 expression. In This study we found that MiR-34a and let-7a expression are reduced in the tumoral tissues. Down-regulation of these two molecules correlated with expression of genes associated with apoptosis. These results suggest that due to the correlation of miR-34a and let-7a with apoptotic and anti-apoptotic pathways these molecules could participate as regulators in advanced clinical stages of breast cancer and should be considered as markers for diagnosis, prognostic assessment and targeted therapy.

Bioinformatic prediction and analysis of glucolipid metabolic regulation by miR-34a in Megalobrama amblycephala

Ling‑Hong Miao,Wen‑Jing Pan,Yan Lin,Bo Liu,Ming‑Chun Ren,Qun‑Lan Zhou,Xian‑Ping Ge 한국유전학회 2017 Genes & Genomics Vol.39 No.12

The objective of this study was to analyze the target genes and regulatory function of miR-34a in Megalobrama amblycephala using second-generation highthroughput sequencing and bioinformatic tools. Functional enrichment analysis was performed by gene ontology. MiR- 34a and target gene expression levels were measured in M. amblycephala fed normal and high-carbohydrate diets. The results revealed that miR-34a was highly conserved in several species, and miR-34a of M. amblycephala has a close evolutionary relationship to that of zebrafish and common carp. miRanda, TargetScan, RNAhybrid predicted 5,185, 6,282 and 2,168 target genes, respectively, and 645 target genes were in common. According to annotation information, the target genes were enriched in phosphate metabolism, glycerophospholipid metabolism, Golgi vesicle transport, cell division, and other biological processes (P < 0.05). Pathway enrichment analysis revealed that these target genes were mainly enriched in alpha-linolenic acid and linoleic acid metabolism, ether lipid metabolism, VEGF signaling pathway, Fc epsilon RI signaling pathway, GnRH signaling pathway, and MAPK signaling pathway (P < 0.05). The regulatory role of miR-34a was more significant in the liver than in the brain of M. amblycephala. MiR-34a regulates glucose lipid homeostasis induced by high glucose diets by upregulating hepatic PI3K/Akt, FOXO, and TOR signaling pathways.

The Long Noncoding RNA NEAT1 Targets miR-34a-5p and Drives Nasopharyngeal Carcinoma Progression via Wnt/β-Catenin Signaling

Yuqing Ji,Man Wang,Xueshen Li,Fusheng Cui 연세대학교의과대학 2019 Yonsei medical journal Vol.60 No.4

Purpose: Long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) has been deemed an oncogene in many humancancers. However, the underlying mechanism of NEAT1 in nasopharyngeal carcinoma (NPC) progression remains largelyunclear. Materials and Methods: Quantitative real-time PCR assay was performed to assess the expression of NEAT1 and miR-34a-5p inNPC tissues and cells. Western blot analysis was used to observe cell epithelial to mesenchymal transition (EMT) and the activationof Wnt/β-catenin signaling in 5-8F cells. MiRNA directly interacting with NEAT1 were verified by dual-luciferase reporter assayand RNA immunoprecipitation. Cell proliferation ability was determined by CCK-8 assay, and cell migration and invasion capacitieswere assessed by transwell assays. An animal model was used to investigate the regulatory effect of NEAT1 on tumorgrowth in vivo. Results: Our data revealed that NEAT1 is upregulated, while miR-34a-5p is downregulated in NPC tissues and cell lines. NEAT1knockdown repressed tumor growth in vitro and in vivo. Additionally, we discovered that NEAT1 directly binds to miR-34a-5pand suppresses miR-34a-5p expression. Moreover, NEAT1 knockdown exerted suppression effects on cell proliferation, migration,invasion, and EMT by miR-34a-5p. NEAT1 knockdown blocked Wnt/β-catenin signaling via miR-34a-5p. Conclusion: Our study demonstrated that NEAT1 targets miR-34a-5p at least partly to drive NPC progression by regulating Wnt/β-catenin signaling, suggesting a potential therapeutic target for NPC.

EBV-encoded EBNA1 regulates cell viability by modulating miR34a-NOX2-ROS signaling in gastric cancer cells

Kim, Seung-Mi,Hur, Dae Young,Hong, Seung-Woo,Kim, Ji Hyun Elsevier 2017 Biochemical and biophysical research communication Vol. No.

<P><B>Abstract</B></P> <P>Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is a viral protein expressed in all EBV-infected cells that induces malignant transformation. EBNA1 is reported to contribute to tumor progression through an increase in reactive oxygen species via nicotinamide adenine dinucleotide phosphate oxidase. However, the underlying molecular mechanism of EBNA1-induced ROS accumulation in gastric cancer is poorly understood. Here, we demonstrated that miR34a regulation by EBNA1 determined cell fate in EBV-infected gastric cancer cells. ROS content and NOX2 expression were higher in EBNA1-expressing SNU719 cells than in EBNA1-nonexpressing SNU638 cells. Downregulation of NOX2 using siRNA technology in SNU719 cells decreased cell viability and ROS content. Regulation of EBNA1 expression in EBV-associated gastric cancers modulated NOX2 expression, ROS content and cell viability. We also showed that upregulation of NOX2 by EBNA1 was mediated by downregulating miRNA34a. Finally, overexpression of miR34a in EBNA1-expressing SNU719 cells induced typical apoptosis, suggesting that reactivation of miR34a in EBNA1-expressing gastric cancer cells could be a strategy for treatment of EBV-infected gastric cancer cells.</P> <P><B>Highlights</B></P> <P> <UL> <LI> ROS content and NOX2 expression are higher in EBV-positive gastric cancer cells relative to EBV-negative gastric cancer cells. </LI> <LI> Upregulation of NOX2 expression by EBNA1 plays an important role in the cell viability of gastric cancer cells. </LI> <LI> Modulation of NOX2 expression by EBNA1 is regulated at the transcriptional level via miR34a. </LI> <LI> Reactivation of miR34a could be a potential anti-cancer strategy in EBV-infected gastric cancer. </LI> </UL> </P>

Consecutive Targetable Smart Nanoprobe for Molecular Recognition of Cytoplasmic microRNA in Metastatic Breast Cancer

Kim, Eunjung,Yang, Jaemoon,Park, Joseph,Kim, Soonhag,Kim, Nam Hee,Yook, Jong In,Suh, Jin-Suck,Haam, Seungjoo,Huh, Yong-Min American Chemical Society 2012 ACS NANO Vol.6 No.10

<P>We report smart nanoprobe, hyaluronic acid (HA)-based nanocontainers containing miR-34a beacons (bHNCs), for the intracellular recognition of miR-34a levels in metastatic breast cancer cells, which is distinct from the imaging of biomarkers such of cell membrane receptors such as HER2. In this study, we demonstrate that a nanoscale vesicle that couples a targeting endocytic route, CD44, and a molecular imaging probe enables the efficient detection of specific miRNAs. Furthermore, bHNCs showed no cytotoxicity and high stability due to the anchored HA molecules on the surface of nanocontainers, and enables the targeted delivery of beacons <I>via</I> CD44 receptor-mediated endocytosis. <I>In vitro</I> and <I>in vivo</I> optical imaging using bHNCs also allow the measurement of miR-34a expression levels due to the selective recognition of the beacons released from the internalized bHNCs. We believe that the technique described herein can be further developed as a cancer diagnostic as well as a miRNA-based therapy of metastatic cancer.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2012/ancac3.2012.6.issue-10/nn300289u/production/images/medium/nn-2012-00289u_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn300289u'>ACS Electronic Supporting Info</A></P>