• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5175-5180
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• 2014

Objective: In this study, tumor-stage predictive abilities of miR21, miR155, miR29a and miR92a were evaluated in rectal cancer (RC). Methods: Expression of miR21, miR155, miR29a and miR92a was detected and quantitated in tumor tissue and in adjacent normal tissue from 40 patients by TaqMan MicroRNA assay. Results: Significant overexpression of miR21, miR155, miR29a and miR92a was observed in RC tissues. While high expression of miR21, miR155 and miR29a in N1-2 and C-D stages presented a potential correlation with N and Duke stages, partial correlation analysis suggested that only miR155 rather than miR21 and miR29a played a greater influencing role. Receiver operating characteristics (ROC) curve analysis showed that miR155 could discriminate N0 from N1-2 with 85.0% sensitivity and 85.0% specificity, N2 from N0-1 with 90.0% sensitivity and 96.7% specificity, and C-D stage from A-B stage with 81.0% sensitivity and 84.2% specificity. Conclusions: Increase in expression of miR155 might represent a novel predictor for RC N and Dukes staging.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2361-2366
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• 2013

Diverse studies have shown that miR-155 is overexpressed in different tumor types. However, the precise molecular mechanism of the ectopic expression of miR-155 in breast cancer is still poorly understood. To further explore the role of miR-155 in breast tumorigenesis, we here assessed the influence of miR-155 antisense oligonucleotide (miR-155 ASO) on MDA-MB-157 cell viability and apoptosis in vitro. Furthermore, the effects of inhibitory effects of miR-155 on the growth of xenograft tumors in vivo were determined with performance of immunohistochemistry to detect expression of caspase-3, a pivotal apoptosis regulatory factor, in xenografts. Transfection efficiency detected by laser confocal microscope was higher than 80%. The level of miR-155 expression was significantly decreased (P<0.05) in the cells transfected with miR-155 ASO, compared with that in cells transfected with a negative control. After being transfected with miR-155 ASO, the viability of MDA-MB-157 cells was reduced greatly (P<0.05) and the number of apoptotic cells was increased significantly. Additionally, miR-155 ASO inhibited the growth of transplanted tumor in vivo and significantly increased the expression of caspase-3. Taken together, our study revealed that miR-155 ASO can induce cell apoptosis and inhibit cell proliferation in vitro. Moreover, miR-155 ASO could significantly repress tumor growth in vivo, presumably by inducing apoptosis via caspase-3 up-regulation. These findings provide experimental evidence for using miR-155 as a therapeutic target of breast carcinoma.

• Molecules and Cells
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• v.40 no.3
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• pp.211-221
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• 2017

Transforming growth factor ${\beta}1$ $(TGF{\beta}1)/Smad4$ signaling plays a pivotal role in maintenance of the dynamic balance between bone formation and resorption. The microRNA miR-155 has been reported to exert a significant role in the differentiation of macrophage and dendritic cells. The goal of this study was to determine whether miR-155 regulates osteoclast differentiation through $TGF{\beta}1/Smad4$ signaling. Here, we present that $TGF{\beta}1$ elevated miR-155 levels during osteoclast differentiation through the stimulation of M-CSF and RANKL. Additionally, we found that silencing Smad4 attenuated the upregulation of miR-155 induced by $TGF{\beta}1$. The results of luciferase reporter experiments and ChIP assays demonstrated that $TGF{\beta}1$ promoted the binding of Smad4 to the miR-155 promoter at a site located in 454 bp from the transcription start site in vivo, further verifying that miR-155 is a transcriptional target of the $TGF{\beta}1/Smad4$ pathway. Subsequently, TRAP staining and qRT-PCR analysis revealed that silencing Smad4 impaired the $TGF{\beta}1$-mediated inhibition on osteoclast differentiation. Finally, we found that miR-155 may target SOCS1 and MITF to suppress osteoclast differentiation. Taken together, we provide the first evidence that $TGF{\beta}1/Smad4$ signaling affects osteoclast differentiation by regulation of miR-155 expression and the use of miR-155 as a potential therapeutic target for osteoclast-related diseases shows great promise.

• Journal of Life Science
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• v.26 no.9
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• pp.1056-1062
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• 2016

Lung cancer is currently the most common malignant disease and the leading cause of mortality in the world and non-small cell lung cancer (NSCLC) accounts for 75-80% of lung cancer cases. miR-155 gene was found to be over expressed in several solid tumors, such as thyroid carcinoma, breast cancer, colon cancer, cervical cancer, pancreatic ductal adenocarcinoma (PDAC) and lung cancer. The aims of this study were to define the expression of miR-155 in lung cancer and its associated clinic-pathologic characteristics. Total RNA was purified from formalin-fixed, paraffin-embedded NSCLC tissues and benign lung tissues. Expression of miR-155 in human lung cancer tissues were evaluated as mean fold changes of miR-155 in cancer tissues compared to benign lung tissues by quantitative real-time reverse transcriptase polymerase chain reaction (real-time qRT-PCR) and associations of miR-155 expression with clinic-pathologic findings of cancer. Compared with the benign control group, miR-155 expression was significantly overexpressed in NSCLCs (p=<0.001). miR-155 was more overexpressed in squamous cell carcinoma than in adenocarcinoma. Poorly differentiated tumors showed significantly overexpression of miR-155 than well-differentiated tumors (p=<0.001). Overexpression of miR-155 was significantly associated with lymph node metastasis (p=<0.05). In survival analysis for all NSCLC patients, high miR-155 expression was significantly correlated with worse overall survival (p=<0.05). These results suggested that miR-155 might play an important role in lung cancer progression and metastasis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.161-166
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• 2014

Lung cancer is the most common causes of cancer-related deaths worldwide, and a lack of effective methods for early diagnosis has greatly impacted the prognosis and survival rates of the affected patients. Tumor-initiating cells (TICs) are considered to be largely responsible for tumor genesis, resistance to tumor therapy, metastasis, and recurrence. In addition to representing a good potential treatment target, TICs can provide clues for the early diagnosis of cancer. MicroRNA (miRNA) alterations are known to be involved in the initiation and progression of human cancer, and the detection of related miRNAs in TICs is an important strategy for lung cancer early diagnosis. As Hsa-miR-155 (miR-155) can be used as a diagnostic marker for non-small cell lung cancer (NSCLC), a smart molecular beacon of miR-155 was designed to image the expression of miR-155 in NSCLC cases. TICs expressing CD133 and CD338 were obtained from A549 cells by applying an immune magnetic bead isolation system, and miR-155 was detected using laser-scanning confocal microscopy. We found that intracellular miR-155 could be successfully detected using smart miR-155 molecular beacons. Expression was higher in TICs than in A549 cells, indicating that miR-155 may play an important role in regulating bio-behavior of TICs. As a non-invasive approach, molecular beacons could be implemented with molecular imaging to diagnose lung cancer at early stages.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7085-7090
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• 2013

Objective: Published data have shown that microRNAs (miRNAs) could play a potential role as diagnostic and prognostic indicators in cancers. Data for the predictive value of microRNA-155 are inconclusive. The aim of the present analysis was therefore to evaluate the role of miR-155 in prognosis for patients with a variety of carcinomas. Methods: Relevant studies were identified by searching PubMed and EMBASE. Data were extracted from studies comparing overall survival (OS), recurrence-free survival (RFS) or cancer-specific survival (CSS) in patients with carcinoma with higher miR-155 expression and those with lower levels. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) of miR-155 for clinical outcome were calculated. Results: A total of 15 studies were included. The pooled hazard ratio (HR) for OS of higher miR-155 expression in cancerous tissue was 1.89 (95% CI: 1.20-2.99, P=0.006), which could markedly predict poorer survival in general cancer. For RFS/CSS, elevated miR-155 was also associated with poor prognosis of cancer (HR=1.50, 95% CI: 1.10-2.05, P=0.01). On subgroup analysis, the pooled HR for OS in non-small cell lung cancer (NSCLC) was 2.09 (95% CI: 0.68-6.41, P > 0.05), but for RFS/CSS was 1.28 (95% CI: 1.05-1.55, P=0.015), with statistical significance; the pooled HRs for OS and RFS/CSS in digestive system neoplasms were 3.04 (95% CI: 1.48-6.24, P=0.003) and 2.61 (95% CI: 1.98-3.42, P<0.05), respectively. Conclusions: The results indicated that the miR-155 expression level plays a prognostic role in patients with cancer, especially NSCLCs and digestive system carcinomas.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2699-2703
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• 2016

Background: Primary hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. MicroRNAs (miRNAs) have great HCC diagnostic potential and circulating miRNAs have been reported as promising biomarkers for various pathologic conditions. Aim: To explore the potential benefit of serum miR-126, miR-129, miR-155, miR-203 and miR-223 as non-invasive diagnostic markers of hepatitis C virus (HCV)-related HCC. Materials and Methods: The expression of miRNA was evaluated using real-time quantitative RT-PCR in 78 serum samples (30 $treatment-na{\ddot{i}}ve$ chronic HCV, 25 post-HCV compensated cirrhosis and 23 $treatment-na{\ddot{i}}ve$ HCC cases). Results: Comparing miRNA fold changes in the HCC group vs the non HCC groups, there was significant fold decrease in miR-126 (P= 0.034), miR-129 (P= 0.006), miR-155 (P= 0.011), miR-203 (P<0.001) and miR-223 (P= 0.013). The highest AUC to differentiate HCC patients from non-HCC was 0.76 for miR-203. Conclusions: Among studied miRNAs, serum miR-203 has the highest potential as a non-invasive biomarker of HCC.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.1909-1912
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• 2014

It is becoming progressively more understandable that between transcription and translation there lies another versatile regulator that quantitatively controls the expression of mRNAs. Identification of miRNAs as key regulators of wide ranging signaling cascades and modulators of different cell-type and context dependent activities attracted basic and clinical scientists to study modes and mechanisms in details. In line with this approach overwhelmingly increasing in vivo and in vitro studies are deepening our understanding regarding miR-421, mir-155 and miR-650 mediated regulation of cellular activities. We also attempt to provide an overview of long non coding RNAs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.5
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• pp.341-347
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• 2020

Objectives: Oral squamous cell carcinoma (OSCC) is one of the most common types of head and neck cancer. MicroRNAs, as new biomarkers, are recommended for diagnosis and treatment of different types of cancers. Bevacizumab, sold under the trade name Avastin, is a humanized whole monoclonal antibody that targets and blocks VEGF-A (vascular endothelial growth factor A; angiogenesis) and oncogenic signaling pathways. Materials and Methods: This study comprised 50 cases suffering from OSCC and 50 healthy participants. Peripheral blood samples were collected in glass test tubes, and RNA extraction was started immediately. Expression levels of miR-155, miR-191, and miR-494 biomarkers in the peripheral blood of OSCC-affected individuals and healthy volunteers in vivo were evaluated using real-time PCR. The influence of Avastin on the expression levels of the aforementioned biomarkers in vitro and in the HN5 cell line was also investigated. Results: Expression levels of miR-155, miR-191, and miR-494 in the peripheral blood of individuals affected by OSCC were higher than in those who were healthy. Moreover, Avastin at a concentration of 400 μM caused a decrease in the expression levels of the three biomarkers and a 1.5-fold, 3.5-fold, and 4-fold increase in apoptosis in the test samples compared to the controls in the HN5 cell line after 24, 48, and 72 hours, respectively. Conclusion: The findings of this study demonstrate that overexpression of miR-155, miR-191, and miR-494 is associated with OSCC, and Avastin is able to regulate and downregulate the expression of those biomarkers and increase apoptosis in cancerous cells in the HN5 cell line.

• Molecules and Cells
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• v.39 no.4
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• pp.330-336
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• 2016

Long non-coding RNAs (lncRNAs) are involved in multiple cellular events, as well as in tumorigenesis. Colon cance-rassociated transcript-1 (CCAT1) gene encodes an lncRNA whose over-activation was observed in an expanding list of primary human solid tumors and tumor cell lines, however its biological roles in acute myeloid leukaemia (AML) has not been reported yet at present. In this study, the aberrant upregulation of CCAT1 was detected in French-American-British M4 and M5 subtypes of adult AML patients. By gain- and loss-of-function analysis, we determined that CCAT1 repressed monocytic differentiation and promoted cell growth of HL-60 by sequestering tumor suppressive miR-155. Accordingly, a significant decrease in miR-155 level was detected in AML patients. Reintroduction of miR-155 into HL-60 cells restored monocytic maturation and repressed cell proliferation. Furthermore, CCAT1 could up-regulated c-Myc via its competing endogenous RNA (ceRNA) activity on miR-155. In conclusion, these results revealed new mechanism of lncRNA CCAT1 in AML development, and suggested that the manipulation of CCAT1 expression could serve as a potential strategy in AML therapy.