Comprehensive expression profiling of microRNAs in laryngeal squamous cell carcinoma

MicroRNAs Expressed during Viral Infection: Biomarker Potential and Therapeutic Considerations

MicroRNAs (miRNAs) are short sequences of noncoding single-stranded RNAs that exhibit inhibitory effects on complementary target mRNAs. Recently, it has been discovered that certain viruses express their own miRNAs, while other viruses activate the transcription of cellular miRNAs for their own benefit. This review summarizes the viral and/or cellular miRNAs that are transcribed during infection, with a focus on the biomarker and therapeutic potential of miRNAs (or their antagomirs). Several human viruses of clinical importance are discussed, namely, herpesviruses, polyomaviruses, hepatitis B virus, hepatitis C virus, human papillomavirus, and human immunodeficiency virus.

Circulating miR-205: a promising biomarker for the detection and prognosis evaluation of bladder cancer

MicroRNA (miRNA) expression profile analysis indicated that miR-205 was upregulated in bladder cancer tissue compared to healthy tissue. The aim of this study is to analyze value of circulating miR-205 for the detection and prognosis evaluation of bladder cancer (BC). Eighty-nine patients with BC and 56 healthy controls (HC) were enrolled in the study. miR-205 expression was determined using TaqMan quantitative real-time polymerase chain reaction assay and further correlated with patients' clinicopathological parameters and follow-up data. The results indicated that plasma miR-205 was upregulated in BC compared with HC (P < 0.001) and in muscle invasive BC (MIBC) compared to nonmuscle invasive BC (NMIBC) (P = 0.016). miR-205 yielded an area under the receiver-operating characteristic curve of 0.950 with 76.4 % sensitivity and 96.4 % specificity in discriminating BC from HC, and 0.668 with 57.1 % sensitivity and 77.0 % specificity in distinguishing MIBC from NMIBC. Plasma miR-205 expression was significantly associated with tumor stage (P < 0.001) and pathological grade (P = 0.048). The results indicated that BC patients with high miR-205 expression experienced shorter disease-free survival and disease-specific survival (P = 0.022 and P = 0.026; P = 0.027 and P = 0.034; respectively), which was not proven by multivariate Cox regression analysis (multi-Cox) (P = 0.0765 and P = 0.279, respectively). Log-rank test showed that NMIBC patients with high miR-205 expression experienced shorter cancer-free survival (P = 0.044). Log-rank test and univariate and multivariate Cox regression analyses did not indicate that high miR-205 expression in NMIBC patients was associated with cancer-specific survival (P = 0.079, P = 0.089, and P = 0.201, respectively). In conclusion, miR-205 may be a promising biomarker for the detection and prognosis evaluation of BC.

Global miRNA Expression Profiling Identifies miR-1290 as Novel Potential oncomiR in Laryngeal Carcinoma

Background

Laryngeal squamous cell carcinoma (LSCC) is the most common group among head and neck cancers. LSCC is characterized by a high incidence in Europe. With the aim of better understanding its genetic background we performed global miRNA expression profiling of LSCC cell lines and primary specimens. By this approach we identified a cohort of 33 upregulated and 9 downregulated miRNA genes in LSCC as compared to epithelial no tumor controls.

Results

Within this group we identified overexpression of the novel miR-1290 gene not reported in the context of LSCC before. Using a combined bioinformatical approach in connection with functional analysis we delineated two putative target genes of miR-1290 namely ITPR2 and MAF which are significantly downregulated in LSCC. They are interesting candidates for tumor suppressor genes as they are implicated in apoptosis and other processes deregulated in cancer.

Conclusion

Taken together, we propose miR-1290 as the new oncomiR involved in LSCC pathogenesis. Additionally, we suggest that the oncogenic potential of miR-1290 might be expressed by the involvement in downregulation of its target genes MAF and ITPR2.

miR-205 promotes proliferation and invasion of laryngeal squamous cell carcinoma by suppressing CDK2AP1 expression

Background

The aberrant expression of microRNAs (miRNAs) has been found in various types of cancer. miR-205 was reported to be upregulated in laryngeal squamous cell carcinoma (LSCC) tissues, however, the mechanisms by which miR-205 functions as a regulator of LSCC are largely unknown.

Results

In this study, Real-time qPCR and Western blot assay showed that expression of miR-205 was upregulated and expression of cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) was downregulated in LSCC tissues. The expression levels of miR-205 were negatively related to those of CDK2AP1 in LSCC tissues and cell lines. Moreover, we found that miR-205 was the upstream regulator of CDK2AP1 and could suppress the CDK2AP1 expression in LSCC cells. 3-(4,5-dimethylthiazal-2-yl)-2,5-diphenyl-tetrazolium bromide assays and transwell invasion assay were performed to test the proliferation and invasion of LSCC cells. Gelatin zymography was used to detect the activity of MMP2 and MMP9. CDK2AP1, c-Myc and CyclinD1 expression in cells was assessed with Western blotting. We found that miR-205 was the upstream regulator of CDK2AP1 and could suppress the expression of CDK2AP1 in LSCC cells. In addition, miR-205 significantly induced cell proliferation and invasion by suppressing CDK2AP1 expression. Consistent with miR-205 inhibitors, overexpressed CDK2AP1 suppressed the activity of MMP2 and MMP9 and c-Myc and CyclinD1 expression in LSCC cells.

Conclusion

These findings help us to better elucidate the molecular mechanisms of LSCC progression and provide a new theoretical basis to further investigate miR-205 as a potential biomarker and a promising approach for LSCC treatment.

The role of miR-145 in stem cell characteristics of human laryngeal squamous cell carcinoma Hep-2 cells

The cancer stem-like cells (CSLCs) are tumorigenic cells promoting initiation, progression, and spread of the tumor. Accumulating evidences suggested the presence of CSLCs in distinct tumors including laryngeal squamous cell carcinoma (LSCC). MicroRNAs have been proposed as significant regulators of carcinogenesis, and several of them have been demonstrated to have direct roles in survival of CSLCs. In this study, we aimed to explore the role of miR-145, which is downregulated in LSCC, on cancer stem cell potency of laryngeal cancer cells. We initially showed the downregulation of miR-145 expression in tumor tissue samples and in CD133-enriched CSLCs. Quantitative reverse-transcription PCR (qRT-PCR) analysis of miR-145-transfected Hep-2 cells demonstrated the inhibitory role of miR-145 on stem cell markers like SOX2, OCT4, KLF4, and ABCG2. We, then, investigated the stem cell features of miR-145-overexpressing Hep-2 cells by sphere formation assay, single-cell cloning assay, and aldehyde dehydrogenase (ALDH) assay, which all demonstrated the inhibition of stem cell potency upon miR-145 overexpression. Further qRT-PCR analysis demonstrated altered expression of epithelial to mesenchymal transition markers in miR-145-overexpressing Hep-2 cells. In conclusion, we demonstrated the regulatory role of miR-145 in stem cell characteristics of Hep-2 cells. Based on these results, we propose that miR-145 might carry crucial roles in LSCC tumorigenesis, prognosis, metastasis, chemoresistance, and recurrence through regulating stem cell properties of tumor cells.

Molecular Aspects of Head and Neck Cancer Therapy

In spite of a rapidly expanding understanding of head and neck tumor biology and optimization of radiation, chemotherapy, and surgical treatment modalities, head and neck squamous cell carcinoma (HNSCC) remains a major cause of cancer-related morbidity and mortality. Although our biologic understanding of these tumors had largely been limited to pathways driving proliferation, survival, and differentiation, the identification of HPV as a major driver of HNSCC and genomic sequencing analyses has dramatically influenced our understanding of tumor biology and approach to therapy. Here, we summarize molecular aspects of HNSCC biology and identify promising areas for potential diagnostic and therapeutic agents.

The role of microRNAs expression in laryngeal cancer

MicroRNAs (miRs, miRs) is a class of small non-coding RNAs, which posttranscriptionally regulate gene expression. Deregulated miRs are frequently obseved in patients with laryngeal cancer. In addition, numerous studies have showed miRs play significant roles in the pathogenesis of laryngeal cancer through regulating tumor cell proliferation, metastasis, invasion and apoptosis. miR can play either an oncogenic or tumor suppressive role in laryngeal cancer. In our review, we summarize the recent researches on laryngeal cancer-associated miRs, focusing on their role in the pathogenesis of laryngeal cancer. As changes in the levels of specific miRs in tissues or serum associate with diagnosis and prognosis of patients, we will also discuss the potential use of miRs in laryngeal cancer diagnosis and prognosis. Furthermore, supplementation of oncomiRs or inhibition of tumor suppressive miRs in vivo may be future therapeutic strategy for laryngeal cancer.

An integrated genome-wide approach to discover deregulated microRNAs in non-small cell lung cancer: Clinical significance of miR-23b-3p deregulation

In spite of significant technical advances, genesis and progression of non-small cell lung cancer (NSCLC) remain poorly understood. We undertook an integrated genetic approach to discover novel microRNAs that were deregulated in NSCLCs. A total 119 primary NSCLCs with matched normal were analyzed for genome-wide copy number changes. We also tested a subset of matched samples by microRNA expression array, and integrated them to identify microRNAs positioned in allelic imbalance area. Our findings support that most of the identified deregulated microRNAs (miR-21, miR-23b, miR-31, miR-126, miR-150, and miR-205) were positioned in allelic imbalance areas. Among microRNAs tested in independent 114 NSCLCs, overexpression of miR-23b was revealed to be a significantly poor prognostic factor of recurrence free survival (HR = 2.40, P = 0.005, 95%CI: 1.32–4.29) and overall survival (HR = 2.35, P = 0.005, 95%CI: 1.30–4.19) in multivariable analysis. In addition, overexpression of miR-23b in H1838 cell line significantly increased cell proliferation, while inhibition of miR-23b in H1437 and H1944 cell lines significantly decreased cell doubling time. In summary, integration of genomic analysis and microRNA expression profiling could identify novel cancer-related microRNAs, and miR-23b could be a potential prognostic marker for early stage NSCLCs. Further biological studies of miR-23b are warranted for the potential development of targeted therapy.

MicroRNA-101 is a potential prognostic indicator of laryngeal squamous cell carcinoma and modulates CDK8

BACKGROUND

Various microRNAs (miRNAs) negatively modulate genes that are involved in cellular proliferation, differentiation, invasion, and apoptosis. In many types of cancer, the expression profiles of these miRNAs are altered. Recently, miR-101 was identified as a tumour suppressor and was found to be expressed at low levels in various types of tumours, including prostate, breast, endometrium, and bladder cancers. However, the function(s) of miR-101 in laryngeal carcinoma remain unknown.

METHODS

The expression levels of miR-101 in laryngeal squamous cell carcinoma (LSCC) tissues and cells were detected by qPCR. Cell proliferation, migration, cell cycle, and apoptosis assay were applied to assess the function(s) of miR-101 in vitro. Nude mice subcutaneous tumour model was used to perform in vivo study. Moreover, we identified Cyclin-dependent kinase 8 (CDK8) as the target of miR-101 by a luciferase assay. The possible downstream effectors of CDK8 were investigated in Wnt/β-catenin signaling pathway. Changes of CDK8, β-catenin, and cyclin D1 protein levels were analyzed by western blotting and immunohistochemical staining. The prognostic effect of miR-101 was evaluated using the Kaplan-Meier method.

RESULTS

Expression of miR-101 was down-regulated in the LSCC tissues compared with the adjacent normal tissues. Furthermore, downregulation of miR-101 correlated with T3-4 tumour grade, lymph node metastasis, and an advanced clinical stage in the LSCC patients examined (P < 0.05). The low level of miR-101 expression was associated with poor prognosis (P < 0.05). CDK8 was identified as the target gene of miR-101 by luciferase reporter assay. Moreover, we showed that up-regulation of miR-101 expression suppressed humen LSCC Hep-2 cells proliferation and migration, and induced cell-cycle arrest. Increased expression of miR-101 induced cells apoptosis both in vitro and in vivo. Correspondingly, exogenous expression of miR-101 significantly reduced the growth of tumour in a LSCC xenograft model. Furthermore, the miR-101 level was inversely correlated with levels of CDK8, β-catenin, and cyclin D1 in western blotting assay and immunohistochemical staining assay.

CONCLUSIONS

These results indicate that miR-101 is a potent tumour repressor that directly represses CDK8 expression. Thus, detection and targeting of miR-101 may represent a novel diagnostic and therapeutic strategy for LSCC patients.

Expression of miR-296-5p as predictive marker for radiotherapy resistance in early-stage laryngeal carcinoma

PURPOSE

Definitive radiation therapy is the mainstay of treatment for early stage laryngeal squamous cell carcinoma (LSCC). However, up to 30% of the patients do not respond to radiotherapy. Unfortunately, we are unable to predict which tumors are likely to respond to radiation, and which will be resistant and persist. Therefore, the development of novel markers to predict response to radiotherapy is urgently needed. This study was designed to evaluate the expression pattern of microRNAs (miRNAs) in LSCC in order to identify markers capable of segregating radioresistant and radiosensitive tumors and to investigate the relationship between the expression of these miRNAs and the prognosis of LSCC.

METHODS

The expression profile of 667 miRNAs was determined in an initial screening of nine early-stage LSCC samples (5 radioresistant and 4 radiosensitive) using TaqMan Low-Density Array (TLDA). Real-time polymerase chain reactions were performed to validate the expression of selected miRNAs in an expanded LSCC cohort (20 radioresistant and 14 radiosensitive). The miRNA expression level was scored as high or low based on the median of the expression in the LSCC samples.

RESULTS

A comprehensive miRNA expression profiling enabled the identification of four miRNAs (miR-296-5p miR-452, miR-183* and miR-200c) differentially expressed in radioresistant LSCC. Moreover, the analysis of additional 34 LSCC samples, confirmed the expression of miR-296-5p as significantly related to radioresistance (p = 0.002) as well as an association of this marker with recurrence (p = 0.025) in early stage laryngeal cancer.

CONCLUSIONS

This study indicates that miR-296-5p expression is associated with resistance to radiotherapy and tumor recurrence in early stage LSCC, showing the feasibility of this marker as a novel prognostic factor for this malignance. Furthermore, miR-296-5p expression could be helpful in the identification of tumors resistant to radiotherapy; thus aiding the clinicians in the choice of the best therapeutic scheme to be used in each case.

microRNA-93 promotes cell proliferation via targeting of PTEN in Osteosarcoma cells

BACKGROUND

Aberrant microRNA (miRNA) expression plays an essential role in osteosarcoma (OS) pathogenesis. Recent studies have shown that dysregulation of miRNA expression is associated with increased tumorigenesis and poor prognosis in several types of cancers, including OS. The aim of this study was to investigate the relevant microRNAs involved in the development of OS.

METHODS

To explore possible oncogenic factors in OS, we used a microarray-based approach to profile changes in the expression of miRNAs and their target mRNAs in five OS cell lines and human mesenchymal stem cells (hMSCs). An miRNA, miR-93, was significantly up-regulated, whereas phosphatase and tensin homologue (PTEN) expression was significantly down-regulated in all tested OS cells, when compared with hMSCs.

RESULTS

When anti-miR-93 was transfected into OS cell lines, PTEN expression was greatly increased, suggesting that PTEN might be a target of miR-93 in ES cells. The expression of phosphorylated Akt protein, which is known to be inversely correlated with that of PTEN, was significantly down-regulated in anti-miR-93-transfected cells. Furthermore, transfection of anti-miR-93 inhibited the proliferation and cell cycle progression of ES cells. In addition, the down-regulation of miR-93 in these cells significantly suppressed tumor growth in vivo.

CONCLUSION

Ectopic expression of miR-93 decreased PTEN protein levels. Furthermore, miR-93 increased proliferation and decreased apoptosis in OS cells, whereas its silencing in these cells inhibited such carcinogenic processes. Taking these observations together, miR-93 can be seen to play a critical role in carcinogenesis through suppression of PTEN, and may serve as a therapeutic target for the treatment of OS.

MicroRNA-34c-5p is related to recurrence in laryngeal squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

Altered microRNA expression has been found in many cancer types, including laryngeal squamous cell carcinoma (LSCC). We investigated the association of LSCC-related miR-34c-5p with disease-free survival and overall survival.

STUDY DESIGN

Retrospective cohort study.

METHODS

Expression levels of miR-34c-5p were detected in 90 LSCC formalin-fixed paraffin-embedded tissues by reverse-transcription quantitative polymerase chain reaction. Overall survival and disease-free survival were evaluated using the Kaplan-Meier method, and multivariate analysis was performed using Cox proportional hazard analysis.

RESULTS

A downregulation of miR-34c-5p expression significantly correlated with worse disease-free and overall survival. In the multivariate analysis, low miR-34c-5p expression was associated with an increased risk of recurrence.

CONCLUSIONS

A downregulation of miR-34c-5p in LSCC is independently associated with unfavorable disease-free survival, suggesting that miR-34c-5p might be a promising marker for evaluating the risk of recurrences.

LEVEL OF EVIDENCE

NA.

Five miRNAs as novel diagnostic biomarker candidates for primary nasopharyngeal carcinoma

MicroRNAs (miRNAs) play an essential role in the development and progression of nasopharyngeal carcinomas (NPC). Despite advances in the field of cancer molecular biology and biomarker discovery, the development of clinically validated biomarkers for primary NPC has remained elusive. In this study, we investigated the expression and clinical significance of miRNAs as novel primary NPC diagnostic biomarkers. We used an array containing 2, 500 miRNAs to identify 22 significant miRNAs, and these candidate miRNAs were validated using 67 fresh NPC and 25 normal control tissues via quantitative real-time PCR (qRT-PCR). Expression and correlation analyses were performed with various statistical approaches, in addition to logistic regression and receiver operating characteristic curve analyses to evaluate diagnostic efficacy. qRT-PCR revealed five differentially expressed miRNAs (miR-93-5p, miR-135b-5p, miR-205-5p and miR-183-5p) in NPC tissue samples relative to control samples (p<0.05), with miR-135b-5p and miR-205-5p being of significant diagnostic value (p<0.01). Moreover, comparison of NPC patient clinicopathologic data revealed a negative correlation between miR-93-5p and miR- 183-5p expression levels and lymph node status (p<0.05). These findings display an altered expression of many miRNAs in NPC tissues, thus providing information pertinent to pathophysiological and diagnostic research. Ultimately, miR-135b-5p and miR-205-5p may be implicated as novel NPC candidate biomarkers, while miR- 93-5p, miR-650 and miR-183-5p may find application as relevant clinical pathology and diagnostic candidate biomarkers.

MicroRNA-24 inhibits growth, induces apoptosis, and reverses radioresistance in laryngeal squamous cell carcinoma by targeting X-linked inhibitor of apoptosis protein

Background

Increasing evidence indicates that dysregulation of microRNAs is involved in tumor progression and development. The aim of this study was to investigate the expression of microRNA-24 (miR-24) and its function in laryngeal squamous cell carcinoma (LSCC).

Methods

Quantitative RT-PCR (qRT-PCR) was used to detect miR-24 expression in LSCC cell lines and tissue samples. MTT, colony formation, and flow cytometry was performed to analyze the effects of miR-24 expression on growth, apoptosis, and radiosensitivity of LSCC cells. Dual-luciferase reporter assays were performed to examine regulation of putative miR-24 targets. Expression of X-linked inhibitor of apoptosis protein (XIAP) mRNA and protein, cleaved or total caspase-3, and cleaved or total PARP protein were detected by qRT-PCR and western blotting assays, respectively.

Results

miR-24 expression levels in LSCC cell lines or tissue were significantly lower than in a normal human keratinocyte cell line or adjacent normal tissues. Functional analyses indicated that re-expression of miR-24 inhibits growth, reduces colony formation, and enhances apoptosis in LSCC cells. In addition, miR-24 upregulation increases LSCC sensitivity to irradiation by enhancing irradiation-induced apoptosis, and luciferase activity indicated that miR-24 binds to the 3′-untranslated region (3′-UTR) of XIAP mRNA. Upregulation of miR-24 inhibits XIAP protein expression in LSCC cells, and silencing of XIAP mimics the effects of miR-24 upregulation on LSCC cells. In addition, XIAP mRNA expression significantly increases in LSCC tissues and is inversely correlated with miR-24 expression.

Conclusions

Our data suggest that miR-24 inhibits growth, increases apoptosis, and enhances radiosensitivity in LSCC cells by targeting XIAP. Therefore, miR-24 may be a potential molecular target for the treatment of human LSCC.

Role of miR-145 in human laryngeal squamous cell carcinoma

BACKGROUND

Laryngeal squamous cell carcinoma (SCC), being an aggressive malignancy, is one of the most commonly diagnosed malignant types of head and neck SCC worldwide. Incidences of laryngeal SCC have been reported to increase recently. In this study, we aimed to explore the biological effects of miR-145 on laryngeal cancer cells.

METHODS

The relative miR-145 level in laryngeal SCC tumor tissues and normal samples was investigated. Then, Hep-2 cells were utilized for functional analysis of miR-145. The proliferation abilities of transfected cells were measured using MTS assay. Scratch assay and single colony migration assay were performed to observe the alterations in migration behavior of transfected cells. Caspase assay and cell cycle analysis were used to investigate the underlying reasons of proliferative inhibition in cells in which miR-145 is overexpressed. Moreover, expression of SOX2 was analyzed using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analysis in Hep-2 cells upon miR-145 transfection and its expression was evaluated in tumor and normal tissue sample of the larynx.

RESULTS

The miR-145 expression in laryngeal SCC tumor samples has been shown to be downregulated. The miR-145 overexpression caused inhibition of proliferation and migration in Hep-2 cells through induction of apoptosis and cell cycle arrest. The SOX2 level was demonstrated to be overexpressed in tumor samples and its expression was significantly decreased in miR-145 overexpressed Hep-2 cells.

CONCLUSION

We have demonstrated the deregulation of miR-145 and SOX2 in laryngeal SCC. Based on these results, we propose that miR-145, as an important regulator of SOX2, carries crucial roles in laryngeal SCC tumorigenesis.

MicroRNA-93 regulates cyclin G2 expression and plays an oncogenic role in laryngeal squamous cell carcinoma

microRNA93 (miR-93) is expressed in the miR‑106b-25 cluster, located in intron 13 of the MCM7 gene. Our previous study found that miR-93 was significantly upregulated in laryngeal squamous cell carcinoma (LSCC), and cyclin G2 (CCNG2) was a potential target of miR-93 in LSCC. However, the possible functions and molecular mechanisms of miR-93 in LSCC remain unknown. In the present study, we show that the level of CCNG2 protein expression was significantly lower in LSCC cancer tissue than normal tissues. The level of CCNG2 was correlated with clinical stages, lymph node metastasis and histological grade. We further show that the expression level of miR-93 was inversely correlated with CCNG2 expression in clinical specimens. Furthermore, gain-of-function assays revealed that miR-93 promoted cell proliferation, decreased apoptosis rates, induced cell cycle arrest and promoted cell migration and invasion, whereas silencing of miR-93 attenuated these carcinogenic processes. In addition, overexpression of miR-93 in Hep-2 cells could reduce the mRNA and protein levels of CCNG2, whereas silencing of miR-93 in Hep-2 cells significantly increased CCNG2 expression. A luciferase assay verified that miR-93 could bind to the 3' untranslated region of CCNG2. Importantly, ectopic expression of CCNG2 in miR-93 cells rescued the effect of miR-93 on LSCC proliferation. Knockdown of CCNG2 promoted cell proliferation resembling that of miR-93 overexpression. These findings demonstrated that miR-93 promotes tumor growth by directly suppressing CCNG2. Taken together, these results suggested that this newly identified miR-93-CCNG2 axis may be involved in LSCC proliferation and progression. Our findings provide novel potential targets for LSCC therapy and prognosis.

MicroRNA-145: a potent tumour suppressor that regulates multiple cellular pathways

MicroRNAs are endogenous, small (18-25 nucleotides) non-coding RNAs, which regulate genes expression by directly binding to the 3'-untranslated regions of the target messenger RNAs. Emerging evidence shows that alteration of microRNAs is involved in cancer development. MicroRNA-145 is commonly down-regulated in many types of cancer, regulating various cellular processes, such as the cell cycle, proliferation, apoptosis and invasion, by targeting multiple oncogenes. This review aims to summarize the recent published literature on the role of microRNA-145 in regulating tumourigenesis and progression, and explore its potential for cancer diagnosis, prognosis and treatment.

Cisplatin and paclitaxel target significant long noncoding RNAs in laryngeal squamous cell carcinoma

The objectives of this study were to identify specific long noncoding RNAs (lncRNAs) in laryngeal squamous cell carcinoma (LSCC) and to clarify the function of cisplatin and paclitaxel on the confirmed laryngeal cancer lncRNAs. Fifty-four pairs of laryngeal tumor and adjacent normal tissue were collected. Candidate lncRNAs were searched in authorized databases. The significant lncRNAs were identified and confirmed through high-output real-time PCR. Chemotherapy assay evaluated the influences of cisplatin and paclitaxel on the significant lncRNAs. Thirty-seven cancer-related candidate lncRNAs were selected. Three up-expressed and two down-expressed significant lncRNAs were identified and confirmed. The expressions of lncRNA CDKN2B-AS1, HOTAIR and MALAT1 were dramatically reduced with the increasing concentration of cisplatin and paclitaxel and also lengthening of the treatment duration. Cisplatin and paclitaxel have target function on significant lncRNAs in LSCC, which presents novel molecular targets to cure LSCC patients and also leads an orientation for developing new drugs.

Tumor progression driven by pathways activating matrix metalloproteinases and their inhibitors

BACKGROUND

Laryngeal squamous cell carcinoma (LSCC) is still a problem worldwide. In some publications interactions between the expression of matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, and their tissue inhibitors (TIMPs) implicated during cancer progression were suggested.

METHODS

The immunohistochemical staining using primary antibody against MMP-2, MMP-9, TIMP-1, TIMP-2, and TIMP-3 were performed. The research group consists of primary N(0) LSCC (20 cases), primary N(+) LSCC (17 cases), and 18 cases of normal mucosa.

RESULTS

Studied MMPs and TIMPs were localized in tumor cells and tumor stroma compartment. MMP-2 expression was higher in stroma compared to tumor cells. MMP-9, TIMP-1, TIMP-2, and TIMP-3 expression was higher in tumor cells than in tumor stroma (P < 0.05). In tumor stroma MMP-2, MMP-9, TIMP-1, and TIMP-3 expression, in LSCC N(0) vs. LSCC N(+) was significantly higher (P < 0.05). The ratios between MMP-2 and TIMP-3 expression were statistically significant (N(0) vs. N(+); P = 0.012). The analyses using classification trees predicted the probability of metastases according to TIMP-3/MMP-14/MMP-2 and MMP-9/TIMP-1 expression levels.

CONCLUSIONS

The presence of MMP-2, MMP-9, TIMP-1, TIMP-2, TIMP-3 expression in tumor cells and in tumor stroma, and additionally different expression according to lymph node involvement suggested of their impact during cancer progression. The significant correlation between TIMP-3 expression and the presence of lymph node metastases and MMP-2 expression might suggest the importance of TIMP-3 as a prognostic factor during tumor progression. The evaluation of molecular markers which participate in MMP-2 activation pathway have a major impact during metastasis.

MicroRNAs and head and neck cancer: reviewing the first decade of research

MicroRNAs are a class of non-coding RNA which regulate gene expression. Their discovery in humans in 2000 has led to an explosion in research in this area in terms of their role as a biomarker, therapeutic target as well as trying to elucidate their function. This review aims to summarise the function of microRNAs as well as to examine how dysregulation at any step in their biogenesis or functional pathway can play a role in the development of cancer. We review which microRNAs are implicated as oncogenic or tumour suppressor in head and neck cancer as well as the data available on the use of microRNAs as diagnostic and prognostic marker. We also discuss routes for future research.

Semi-supervised learning for potential human microRNA-disease associations inference

MicroRNAs play critical role in the development and progression of various diseases. Predicting potential miRNA-disease associations from vast amount of biological data is an important problem in the biomedical research. Considering the limitations in previous methods, we developed Regularized Least Squares for MiRNA-Disease Association (RLSMDA) to uncover the relationship between diseases and miRNAs. RLSMDA can work for diseases without known related miRNAs. Furthermore, it is a semi-supervised (does not need negative samples) and global method (prioritize associations for all the diseases simultaneously). Based on leave-one-out cross validation, reliable AUC have demonstrated the reliable performance of RLSMDA. We also applied RLSMDA to Hepatocellular cancer and Lung cancer and implemented global prediction for all the diseases simultaneously. As a result, 80% (Hepatocellular cancer) and 84% (Lung cancer) of top 50 predicted miRNAs and 75% of top 20 potential associations based on global prediction have been confirmed by biological experiments. We also applied RLSMDA to diseases without known related miRNAs in golden standard dataset. As a result, in the top 3 potential related miRNA list predicted by RLSMDA for 32 diseases, 34 disease-miRNA associations were successfully confirmed by experiments. It is anticipated that RLSMDA would be a useful bioinformatics resource for biomedical researches.

The role of microRNA in head and neck cancer: current knowledge and perspectives

Head and neck cancer is one of the most commonly diagnosed malignancies worldwide. Patients with advanced disease stages frequently develop recurrences or distant metastasis, which results a five-year survival rates of less than 60% despite considerable advances in multimodality therapy. A better understanding of molecular basis of tumorigenesis is required to improve clinical outcomes and to develop new anti-cancer drugs. microRNAs (miRNAs) are a class of small, non-coding, RNA molecules that modulate gene expression post-transcriptionally. They are important regulator in normal biological process; however miRNAs deregulation has been observed in many different tumors and is involved in tumorigenesis. miRNAs may act as tumor suppressors or as oncogenes. Several studies on head and neck cancer demonstrated how aberrant expression of miRNAs is involved in proliferation, metastasis, chemoresistence, and radioresistance. In addition, miRNAs are excellent biomarker targets because they circulate stable in human body fluids and can be obtained with non-invasive methods. Moreover, miRNAs up and down regulation has been correlated with specific cancer phenotype (poor prognosis, aggressiveness and resistance to treatment), playing a role as prognostic biomarkers. This review summarizes current finding on miRNAs in head and neck cancer and their potential role as target for next drug therapy.

Micro-ribonucleic acid expression profiling and bioinformatic target gene analyses in laryngeal carcinoma

Abnormal expression of micro-ribonucleic acid (miRNA) might be clinically valuable as a biomarker or treatment target in the early diagnosis, treatment, and prognosis of tumors. However, little is known concerning abnormal miRNA expression of laryngeal carcinoma, one of the most commonly encountered head and neck tumors. Microarray analysis was used to obtain miRNA-expression profiles of ten pairs of freshly frozen laryngeal carcinoma tissue and surrounding normal tissue specimens. Characteristic miRNAs that were significantly related to laryngeal carcinoma were identified. Verification was performed using an additional 32 pairs of samples. The expression of two miRNAs (miR-21-3p and miR-106b-3p) was upregulated in both microarray and quantitative real-time polymerase chain-reaction analyses, whereas the expression of six miRNAs (let-7f-5p, miR-10a-5p, miR-125a-5p, miR-144-3p, miR-195-5p, and miR-203) was downregulated. The decreased expression of let-7f-5p and miR-195-5p is a novel finding in head and neck cancer. The target genes of these miRNAs were also predicted through multiple software programs. The differential expression of miRNAs might be related to the early onset and development of laryngeal carcinoma, and may be exploited as new biomarkers and therapeutic targets in the treatment of laryngeal carcinoma.

MicroRNA-205 suppresses proliferation and promotes apoptosis in laryngeal squamous cell carcinoma

MicroRNAs were reported to be involved in the modulation of tumor development. The aim of our study was to investigate the effect of miR-205 on proliferation and apoptosis of laryngeal squamous cell carcinoma (LSCC) and seek associations between miR-205 and Bcl-2 using in vitro and in vivo methods. Real-time qPCR was used to analyze the expression of miR-205 in LSCC samples and Hep-2 cell line. Apoptosis, cell cycle, and proliferation (MTT) assays were performed to test the apoptosis and proliferation of LSCC cells after miR-205 transfection. Bcl-2 expression in cells was assessed with Western blotting. The tumorigenicity of LSCC cells was evaluated in nude mice model. MiR-205 was significantly down-regulated in LSCC tissues compared to adjacent normal tissues. Lower expression of miR-205 was indicated to be statistically related with advanced clinical stage and T3-4 grades. We found that restoration of miR-205 down-regulated the proliferative markers of dihydrofolate reductase and proliferating cell nuclear antigen and apoptotic regulator of Bcl-2. The findings in vitro and in vivo showed miR-205 could suppress cell proliferation and induce cell apoptosis. In addition, Bcl-2 was identified as one of the direct targets of miR-205 in LSCC cells. These results suggest that miR-205 may play as a tumor suppressor in LSCC, probably by targeting Bcl-2 and serve as a potential target for therapeutic intervention.

Identification of predictive biomarkers for early diagnosis of larynx carcinoma based on microRNA expression data

The abnormal expression of microRNAs (miRNAs) plays a key role in tumorigenesis. In order to identify potential miRNA biomarkers for early diagnosis of larynx carcinoma, we employed a miRNA microarray technique and applied bioinformatic algorithms to characterize miRNA classifiers in early larynx carcinoma and normal esophageal mucosa tissue samples from 69 patients who were selected retrospectively for this study. We identified 47 miRNAs that were significantly differentially expressed in primary larynx tumor tissues compared to normal tissues using a SAM algorithm. Of these, 30 were up-regulated and 17 down-regulated in early larynx cancer, including hsa-miR-657, which was overexpressed, and hsa-miR-1287, which was underexpressed. These two candidate miRNA biomarkers were combined as a single classifier to recognize the biological characteristics in early larynx carcinoma. Real-time quantitative reverse-transcription PCR validated the microarray results in both trial and test samples. The hsa-miR-657-hsa-miR-1287 classifier displayed high sensitivity and specificity for discriminating between early larynx carcinoma and normal mucosa tissues, suggesting they may be suitable as potential predictive biomarkers for the early diagnosis of larynx carcinoma.

MicroRNA-196a is a putative diagnostic biomarker and therapeutic target for laryngeal cancer

Background

MicroRNA (miRNA) is an emerging subclass of small non-coding RNAs that regulates gene expression and has a pivotal role for many physiological processes including cancer development. Recent reports revealed the role of miRNAs as ideal biomarkers and therapeutic targets due to their tissue- or disease-specific nature. Head and neck cancer (HNC) is a major cause of cancer-related mortality and morbidity, and laryngeal cancer has the highest incidence in it. However, the molecular mechanisms involved in laryngeal cancer development remain to be known and highly sensitive biomarkers and novel promising therapy is necessary.

Methodology/Principal Findings

To explore laryngeal cancer-specific miRNAs, RNA from 5 laryngeal surgical specimens including cancer and non-cancer tissues were hybridized to microarray carrying 723 human miRNAs. The resultant differentially expressed miRNAs were further tested by using quantitative real time PCR (qRT-PCR) on 43 laryngeal tissue samples including cancers, noncancerous counterparts, benign diseases and precancerous dysplasias. Significant expressional differences between matched pairs were reproduced in miR-133b, miR-455-5p, and miR-196a, among which miR-196a being the most promising cancer biomarker as validated by qRT-PCR analyses on additional 84 tissue samples. Deep sequencing analysis revealed both quantitative and qualitative deviation of miR-196a isomiR expression in laryngeal cancer. In situ hybridization confirmed laryngeal cancer-specific expression of miR-196a in both cancer and cancer stroma cells. Finally, inhibition of miR-196a counteracted cancer cell proliferation in both laryngeal cancer-derived cells and mouse xenograft model.

Conclusions/Significance

Our study provided the possibilities that miR-196a might be very useful in diagnosing and treating laryngeal cancer.

Differential expression of microRNAs in plasma of patients with laryngeal squamous cell carcinoma: potential early-detection markers for laryngeal squamous cell carcinoma

PURPOSE

Altered microRNA (miRNA) expression has been found in many cancers, including lung, breast, prostate, bladder and colorectal cancer. Many recent studies have demonstrated that aberrant plasma miRNAs were also found in various types of cancers. However, the alteration in plasma miRNA expressions in laryngeal squamous cell carcinoma (LSCC) remains unclear. The present study aimed to investigate the alterations in plasma miRNAs in LSCC.

METHODS

In the present study, the expression profiles of 738 miRNAs in plasma from 20 patients and 44 healthy subjects were evaluated using high-throughput real-time quantitative polymerase chain reaction.

RESULTS

Our results demonstrated that expression levels of 17 miRNAs were significantly upregulated in patients with LSCCs when compared to control group (p < 0.05). Expression levels of nine miRNAs were found significantly downregulated in LSCC patients (p < 0.05). In addition, 17 miRNAs were expressed only in LSCC group, and five of these miRNAs (miR-331-3p, 603, 1303, 660-5p and 212-3p) are LSCC specific and never seen before in plasma of any human subject.

CONCLUSION

In conclusion, our study suggests that detecting these LSCC-specific miRNAs in plasma might serve as novel noninvasive biomarkers for LSCC.

Differential expression of microRNAs in plasma of patients with laryngeal squamous cell carcinoma: potential early-detection markers for laryngeal squamous cell carcinoma

PURPOSE

Altered microRNA (miRNA) expression has been found in many cancers, including lung, breast, prostate, bladder and colorectal cancer. Many recent studies have demonstrated that aberrant plasma miRNAs were also found in various types of cancers. However, the alteration in plasma miRNA expressions in laryngeal squamous cell carcinoma (LSCC) remains unclear. The present study aimed to investigate the alterations in plasma miRNAs in LSCC.

METHODS

In the present study, the expression profiles of 738 miRNAs in plasma from 20 patients and 44 healthy subjects were evaluated using high-throughput real-time quantitative polymerase chain reaction.

RESULTS

Our results demonstrated that expression levels of 17 miRNAs were significantly upregulated in patients with LSCCs when compared to control group (p < 0.05). Expression levels of nine miRNAs were found significantly downregulated in LSCC patients (p < 0.05). In addition, 17 miRNAs were expressed only in LSCC group, and five of these miRNAs (miR-331-3p, 603, 1303, 660-5p and 212-3p) are LSCC specific and never seen before in plasma of any human subject.

CONCLUSION

In conclusion, our study suggests that detecting these LSCC-specific miRNAs in plasma might serve as novel noninvasive biomarkers for LSCC.

MicroRNA-93 regulates NRF2 expression and is associated with breast carcinogenesis

MicroRNAs (miRNA) are small non-coding RNAs that regulate the expression of approximately 60% of all human genes and play important roles in disease processes. Recent studies have demonstrated a link between dysregulated expression of miRNAs and breast carcinogenesis. Long-term estrogen exposure is implicated in development of human breast cancers, yet underlying mechanisms remain elusive. We have recently demonstrated that antioxidant vitamin C (vit C) prevents estrogen-induced breast tumor development. In this study, we investigated the role of vit C in the regulation of microRNA-93 (miR-93) and its target gene(s) in a rat model of mammary carcinogenesis. Female August Copenhagen Irish (ACI) rats were treated with vit C in the presence or absence of 17β-estradiol (E2) for 8 months. We demonstrate an increased expression of the miR-93 in E2-treated mammary tissues and in human breast cell lines and vit C treatment reverted E2-mediated increase in miR-93 levels. MiRNA target prediction programs suggest one of the target genes of miR-93 to be nuclear factor erythroid 2-related factor 2 (NRF2). In contrast with miR-93 expression, NRF2 protein expression was significantly decreased in E2-treated mammary tissues, mammary tumors, and in breast cancer cell lines, and its expression was significantly increased after vit C treatment. Ectopic expression of miR-93 decreased protein expression of NRF2 and NRF2-regulated genes. Furthermore, miR-93 decreased apoptosis, increased colony formation, mammosphere formation, cell migration and DNA damage in breast epithelial cells, whereas silencing of miR-93 in these cells inhibited these carcinogenic processes. Taken together, our findings suggest an oncogenic potential of miR-93 during E2-induced breast carcinogenesis.

Identification of circulating microRNAs as potential biomarkers for detecting acute myeloid leukemia

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. The disease is characterized by various cytogenetic and molecular abnormalities with distinct prognoses and gene expression profiles. Emerging evidence has suggested that circulating microRNAs (miRNAs) could serve as noninvasive biomarkers for cancer detection; however, little is known about circulating miRNA profiles in AML patients. In this study, a genome-wide serum miRNA expression analysis was performed using Solexa sequencing for initial screen, followed by validation with real-time PCR assays. The analysis was conducted on training and verification sets of serum samples from 140 newly diagnosed AML patients and 135 normal adult donors. After a two-phase selection and validation process, 6 miRNAs, miR-10a-5p, miR-93-5p, miR-129-5p, miR-155-5p, miR-181b-5p and miR-320d, were found to have significantly different expression levels in AML compared with control serum samples. Furthermore, unsupervised clustering analysis revealed the remarkable ability of the 6-miRNA profile to differentiate between AML patients and normal controls. The areas under the ROC curve for the selected miRNAs ranged from 0.8129 to 0.9531. More importantly, miR-181b-5p levels in serum were significantly associated with overall survival. These data demonstrated that the expression patterns of circulating miRNAs were systematically altered in AML and miR-181b-5p may serve as a predictor for overall survival in AML patients.