• Biomedical Science Letters
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• v.19 no.4
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• pp.348-352
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• 2013

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.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7619-7625
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• 2015

Background: Aberrant microRNA expression has been associated with the pathogenesis of a variety of human malignancies including oral squamous cell carcinoma (SCC). In this study, we examined primary oral SCCs for the expression of 6 candidate miRNAs, of which five (miR-34a, miR-143, miR-373, miR-380-5p, and miR-504) regulate the tumor suppressor TP53 and one (miR-99a) is involved in AKT/mTOR signaling. Materials and Methods: Tumor tissues (punch biopsies) were collected from 52 oral cancer patients and as a control, 8 independent adjacent normal tissue samples were also obtained. After RNA isolation, we assessed the mature miRNA levels of the 6 selected candidates against RNU44 and RNU48 as endogenous controls, using specific TaqMan miRNA assays. Results: miR-34a, miR-99a, miR-143 and miR-380-5p were significantly down-regulated in tumors compared to controls. Moreover, high levels of miR-34a were associated with alcohol consumption while those of miR-99a and miR-143 were associated with advanced tumor size. No significant difference was observed in the levels of miR-504 between the tumors and controls whereas miR-373 was below the detection level in all but two tumor samples. Conclusions: Low levels of miR-380-5p and miR-504 that directly target the 3'UTR of TP53 suggest that p53 may not be repressed by these two miRNAs in OSCC. On the other hand, low levels of miR-34a or miR-143 may relieve MDM4 and SIRT1 or MDM2 respectively, which will sequester p53 indicating an indirect mode of p53 suppression in oral tumors.

• Molecules and Cells
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• v.45 no.6
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• pp.403-412
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• 2022

Hypoxia leads to significant cellular stress that has diverse pathological consequences such as cardiovascular diseases and cancers. MicroRNAs (miRNAs) are one of regulators of the adaptive pathway in hypoxia. We identified a hypoxia-induced miRNA, miR-34c, that was significantly upregulated in hypoxic human umbilical cord vein endothelial cells (HUVECs) and in murine blood vessels on day 3 of hindlimb ischemia (HLI). miR-34c directly inhibited BCL2 expression, acting as a toggle switch between apoptosis and autophagy in vitro and in vivo. BCL2 repression by miR-34c activated autophagy, which was evaluated by the expression of LC3-II. Overexpression of miR-34c inhibited apoptosis in HUVEC as well as in a murine model of HLI, and increased cell viability in HUVEC. Importantly, the number of viable cells in the blood vessels following HLI was increased by miR-34c overexpression. Collectively, our findings show that miR-34c plays a protective role in hypoxia, suggesting a novel therapeutic target for hypoxic and ischemic diseases in the blood vessels.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1887-1890
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• 2016

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.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.11
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• pp.1532-1536
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• 2015

To verified the target genes of miR-34c, bioinformatics software was used to predict the targets of miR-34c. Three possible target genes of miR-34c related to spermatogenesis and male reproductive development: zinc finger protein 148 (ZNF148), kruppel-like factor 4 (KLF4), and platelet-derived growth factor receptor alpha (PDGFRA) were predicted. Then, the expression of miR-34c and its target genes were detected in swine testicular tissue at different developmental stages by quantitative polymerase chain reaction. The results suggested that the expression of PDGFRA has the highest negative correlation with miR-34c. Then immunohistochemical staining was done to observe the morphology of swine testicular tissue at 2-days and 3, 4, 5-months of age, which indicated that PDGFRA was mainly expressed in the support cells near the basement membrane during the early development stages of testicular tissue, but that the expression of PDGFRA was gradually reduced in later stages. Therefore, western blot analyzed that the highest expression of PDGFRA was generated in 2-days old testicular tissues and the expression levels reduced at 3 and 4-months old, which correlated with the results of immunohistochemical staining. In conclusion, PDGFRA is a target gene of miR-34c.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6099-6104
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• 2015

Background: Previous studies investigating the association between miR-34b/c rs4938723 polymorphism and cancer risk showed inconclusive. Here, we performed meta-analysis to investigate the association between miR- 34b/c rs4938723 polymorphism and digestive cancer risk. Materials and Methods: Literature database including PubMed, OVID, Chinese National Knowledge Infrastructure (CNKI) were searched for publications concerning the association between the miR-34b/c rs4938723 polymorphism and digestive cancer risk. Results: A total of 6 studies consisting of 3246 cases and 3568 controls were included in this meta-analysis. The combined analysis suggested the miR-34b/c rs4938723 polymorphism significantly reduced digestive cancer risk under allelic model, homogeneous co-dominant model and recessive model (C vs T: OR=0.88, 95%CI=0.82-0.95, p-value=0.001; CC vs TT: OR =0.67, 95%CI=0.57-0.80, p-value=0.000; CC vs TT/TC: OR=0.68, 95%CI=0.58-0.80, p-value=0.000). Q-test and I2 test revealed no significant heterogeneity in all genotype comparisons. The Begger's funnel plot and Egger's test did not show significant publication bias. Conclusions: The current evidence supports the conclusion that the miR-34b/c rs4938723 polymorphism decreases an individual's susceptibility to digestive cancers.

• BMB Reports
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• v.46 no.6
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• pp.316-321
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• 2013

Gastric cancer remains the main cause of cancer death all around the world, and upregulated activation of the nonreceptor tyrosine kinase c-SRC (SRC) is a key player in the development. In this study, we found that expression of Src is also increased in clinical gastric cancer samples, with the protein level increased more significantly than that at the RNA level. Further study revealed that miR34a and miR203, two tumor suppressive miRNAs, inversely correlate with the expression of Src. Restoration of miR34a and miR203 decreased Src expression in gastric cancer cell lines, which in turn inhibited cell growth and cell migration. In summary, our study here revealed that posttranscriptional regulation of Src contributes to the deregulated cell growth and metastasis in gastric cancer, and targeting Src by miR34a or miR203 mimics would be a promising strategy in therapy.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.455-459
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• 2017

MicroRNAs (miRNAs/miRs) are a group of small noncoding RNAs that modulate gene expression. Many studies, demonstrating altered expressions of specific miRNAs in diverse types of human neoplasia, suggested that they may play a key role in tumorigenesis. Recently, miRNA genes were found to be abnormally expressed in several types of cancer, including endometrial cancer. However, miR-23b and miR-203 expression in endometrial cancer has yet to be studied in Korea. As such, the purpose of this study was to analyze miR-23b and miR-203 expressions in endometrial cancer and to evaluate the relationship between miR-23b and miR-203 expressions. A retrospective study was carried out on the formalin-fixed, paraffin-embedded tissues of 42 endometrial cancer tissues using quantitative real-time PCR. In endometrial cancer tissues, miR-23b expression levels ($2.70{\pm}4.45$) were higher than miR-203 expression levels ($-2.34{\pm}4.08$). Endometrial cancer tissues showed an overexpression of miR-23b in 30 (71.4%) of the 42 endometrial cancer cases, whereas miR-203 was underexpressed in 29 (69.0%) of the 42 cases. There was a significant association between miR-23b and miR-203 expressions in endometrial cancer tissues (p=0.0005). These findings suggest that miR-23b and miR-203 expressions may be involved in endometrial carcinogenesis. More studies are needed to further define the relationship between miR-23b and miR-203 expressions and tissue-specific protein expression.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7251-7255
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• 2014

MicroRNAs (miRNAs) act as tumor suppressors or promoters in neoplasia by regulating relative geneexpression. The association between a single nucleotide polymorphism (SNP) rs4938723 in miR-34b/c and susceptibility to cancers was inconsistent in previous studies. In this study, we conducted a literature search of PubMed, Web of Science and Embase to identify all relevant studies in this meta-analysis with 6,036 cases and 6,204 controls. We found that the miR-34b/c rs4938723 polymorphism was significantly associated with increased risk of cancers in the heterozygous model (TC versus TT, OR=1.09, 95% CI=1.01-1.18, P=0.02). Subgroup analysis also revealed increased risk for Asian ethnicity in the heterozygous model (TC versus TT, OR=1.12, 95% CI=1.02-1.22, P=0.02), but decreased risk of colorectal cancer in homozygote model (CC versus TT, OR=0.66, 95% CI=0.47-0.92, P=0.02) and in the recessive model (CC versus TC+TT, OR=0.67, 95% CI=0.48-0.93, P=0.02) by cancer type. The current meta-analysis indicated that the miR-34b/c rs4938723 polymorphism may decrease susceptibility to colorectal cancer. Well-designed studies with larger sample size are required to further validate the results.

• Molecules and Cells
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• v.41 no.6
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• pp.553-561
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• 2018

Icariside II (ICA II) is used in erectile dysfunction treatment. Adipose tissue-derived stem cells (ADSCs) are efficient at improving erectile function. This study aimed to explore the action mechanism of ADSCs in improving erectile function. ADSCs were isolated from the adipose tissues of rats. Cell proliferation was determined using the Cell Counting Kit-8 (CCK-8) assay. The expressions of mRNA and protein were determined separately through qRT-PCR and western blot. The endogenous expressions of related genes were regulated using recombinant plasmids and cell transfection. A Dual-Luciferase Reporter Assay was performed to determine the interaction between miR-34a and STAT3. Rat models with bilateral cavernous nerve injuries (BCNIs) were used to assess erectile function through the detection of mean arterial pressure (MAP) and intracavernosal pressure (ICP). ICA II promoted ADSCs' proliferation and differentiation to Schwann cells (SCs) through the inhibition of miR-34a. Suppressed miR-34a promoted the differentiation of ADSCs to SCs by upregulating STAT3. ICA II promoted the differentiation of ADSCs to SCs through the miR-34a/STAT3 pathway. The combination of ICA II and ADSCs preserved the erectile function of the BCNI model rats. ADSCs treated with ICA II markedly preserved the erectile function of the BCNI model rats, which was reversed through miR-34a overexpression. ICA II promotes the differentiation of ADSCs to SCs through the miR34a/STAT3 pathway, contributing to erectile function preservation after the occurrence of a cavernous nerve injury.