MicroRNA‑375 inhibits oral squamous cell carcinoma cell migration and invasion by targeting platelet‑derived growth factor‑A

Construction and assessment of an angiogenesis-related gene signature for prognosis of head and neck squamous cell carcinoma

OBJECTIVE

Angiogenesis-associated genes (AAGs) play a critical role in cancer patient survival. However, there are insufficient reports on the prognostic value of AAGs in head and neck squamous cell carcinoma (HNSC). Therefore, this study aimed to investigate the correlation between AAG expression levels and survival in HNSC patients, explore the predictive value of signature genes and lay the groundwork for future in-depth research.

METHODS

Relevant data for HNSC were obtained from the databases. AAGs-associated signature genes linked to prognosis were screened to construct a predictive model. Further analysis was conducted to determine the functional correlation of the signature genes.

RESULTS

The signature genes (STC1, SERPINA5, APP, OLR1, and PDGFA) were used to construct prognostic models. Patients were divided into high-risk and low-risk groups based on the calculated risk scores. Survival analysis showed that patients in the high-risk group had a significantly lower overall survival than those in the low-risk group (P < 0.05). Therefore, this prognostic model was an independent prognostic factor for predicting HNSC. In addition, patients in the low-risk group were more sensitive to multiple anti-cancer drugs. Functional correlation analysis showed a good correlation between the characteristic genes and HNSC metastasis, invasion, and angiogenesis.

CONCLUSION

This study established a new prognostic model for AAGs and may guide the selection of therapeutic agents for HNSC. These genes have important functions in the tumor microenvironment; it also provides a valuable resource for the future clinical trials investigating the relationship between HNSC and AAGs.

Possible Role of miR-375-3p in Cervical Lymph Node Metastasis of Oral Squamous Cell Carcinoma

No clinically useful predictors of latent cervical lymph node metastasis (LNM) in early oral squamous cell carcinoma (OSCC) are available. In this study, we focused on the microRNAs (miRNAs) involved in the expression of numerous genes and explored those associated with latent cervical LNM in early OSCC (eOSCC). First, microarray and RT-PCR analyses revealed a significant downregulation of miR-375-3p expression in primary eOSCC tissues with latent cervical LNM. Next, we examined the effects of miR-375-3p mimics on the growth and migration of four human OSCC cell lines that do not express miR-375-3p. The overexpression of miR-375-3p significantly suppressed the cell proliferation and migration of human OSCC cells in vitro. Furthermore, miR-375-3p mimics markedly inhibited the subcutaneously xenografted human OSCC tumors. Finally, we found the genes involved in the PI3K-AKT pathway and cell migration as target gene candidates of miR-375-3p in human OSCC cells. These findings suggest that miR-375-3p functions as a tumor suppressive-miRNA in OSCC and may serve as a potential biomarker for the prediction of latent cervical LNM in eOSCC and a useful therapeutic target to suppress OSCC progression.

Unraveling the role of miRNAs in the diagnosis, progression, and drug resistance of oral cancer

Oral cancer (OC) is a widely observed neoplasm on a global scale. Over time, there has been an increase in both its fatality and incidence rates. Oral cancer metastasis is a complex process that involves a number of cellular mechanisms, including invasion, migration, proliferation, and escaping from malignant tissue through either lymphatic or vascular channels. MicroRNAs (miRNAs) are a crucial class of short non-coding RNAs recognized as significant modulators of diverse cellular processes and exert a pivotal influence on the carcinogenesis pathway, functioning either as tumor suppressors or as oncogenes. It has been shown that microRNAs (miRNAs) have a role in metastasis at several stages, including epithelial-mesenchymal transition, migration, invasion, and colonization. This regulation is achieved by targeting key genes involved in these pathways by miRNAs. This paper aims to give a contemporary analysis of OC, focusing on its molecular genetics. The current literature and emerging advancements in miRNA dysregulation in OC are thoroughly examined. This project would advance OC diagnosis, prognosis, therapy, and therapeutic implications.

MiRNA-related metastasis in oral cancer: moving and shaking

Across the world, oral cancer is a prevalent tumor. Over the years, both its mortality and incidence have grown. Oral cancer metastasis is a complex process involving cell invasion, migration, proliferation, and egress from cancer tissue either by lymphatic vessels or blood vessels. MicroRNAs (miRNAs) are essential short non-coding RNAs, which can act either as tumor suppressors or as oncogenes to control cancer development. Cancer metastasis is a multi-step process, in which miRNAs can inhibit or stimulate metastasis at all stages, including epithelial-mesenchymal transition, migration, invasion, and colonization, by targeting critical genes in these pathways. On the other hand, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), two different types of non-coding RNAs, can regulate cancer metastasis by affecting gene expression through cross-talk with miRNAs. We reviewed the scientific literature (Google Scholar, Scopus, and PubMed) for the period 2000-2023 to find reports concerning miRNAs and lncRNA/circRNA-miRNA-mRNA networks, which control the spread of oral cancer cells by affecting invasion, migration, and metastasis. According to these reports, miRNAs are involved in the regulation of metastasis pathways either by directly or indirectly targeting genes associated with metastasis. Moreover, circRNAs and lncRNAs can induce or suppress oral cancer metastasis by acting as competing endogenous RNAs to inhibit the effect of miRNA suppression on specific mRNAs. Overall, non-coding RNAs (especially miRNAs) could help to create innovative therapeutic methods for the control of oral cancer metastases.

Non-Coding RNAs in Oral Cancer: Emerging Roles and Clinical Applications

Oral cancer (OC) is among the most prevalent cancers in the world. Certain geographical areas are disproportionately affected by OC cases due to the regional differences in dietary habits, tobacco and alcohol consumption. However, conventional therapeutic methods do not yield satisfying treatment outcomes. Thus, there is an urgent need to understand the disease process and to develop diagnostic and therapeutic strategies for OC. In this review, we discuss the role of various types of ncRNAs in OC, and their promising clinical implications as prognostic or diagnostic markers and therapeutic targets. MicroRNA (miRNA), long ncRNA (lncRNA), circular RNA (circRNA), PIWI-interacting RNA (piRNA), and small nucleolar RNA (snoRNA) are the major ncRNA types whose involvement in OC are emerging. Dysregulated expression of ncRNAs, particularly miRNAs, lncRNAs, and circRNAs, are linked with the initiation, progression, as well as therapy resistance of OC via modulation in a series of cellular pathways through epigenetic, transcriptional, post-transcriptional, and translational modifications. Differential expressions of miRNAs and lncRNAs in blood, saliva or extracellular vesicles have indicated potential diagnostic and prognostic importance. In this review, we have summarized all the promising aspects of ncRNAs in the management of OC.

The paradigm of miRNA and siRNA influence in Oral-biome

Short nucleotide sequences like miRNA and siRNA have attracted a lot of interest in Oral-biome investigations. miRNA is a small class of non-coding RNA that regulates gene expression to provide effective regulation of post-transcription. On contrary, siRNA is 21-25 nucleotide dsRNA impairing gene function post-transcriptionally through inhibition of mRNA for homologous dependent gene silencing. This review highlights the application of miRNA in oral biome including oral cancer, dental implants, periodontal diseases, gingival fibroblasts, oral submucous fibrosis, radiation-induced oral mucositis, dental Pulp, and oral lichenoid disease. Moreover, we have also discussed the application of siRNA against the aforementioned disease along with the impact of miRNA and siRNA to the various pathways and molecular effectors pertaining to the dental diseases. The influence of upregulation and downregulation of molecular effector post-treatment with miRNA and siRNA and their impact on the clinical setting has been elucidated. Thus, the mentioned details on application of miRNA and siRNA will provide a novel gateway to the scholars to not only mitigate the long-lasting issue in dentistry but also develop new theragnostic approaches.

The Connection between MicroRNAs and Oral Cancer Pathogenesis: Emerging Biomarkers in Oral Cancer Management

Oral cancer is a common human malignancy that still maintains an elevated mortality rate despite scientific progress. Tumorigenesis is driven by altered gene expression patterns of proto-oncogenes and tumor-suppressor genes. MicroRNAs, a class of short non-coding RNAs involved in gene regulation, seem to play important roles in oral cancer development, progression, and tumor microenvironment modulation. As properties of microRNAs render them stable in diverse liquid biopsies, together with their differential expression signature in cancer cells, these features place microRNAs at the top of promising biomarkers for diagnostic and prognostic values. In this review, we highlight eight expression levels and functions of the most relevant microRNAs involved in oral cancer development, progression, and microenvironment sustainability. Furthermore, we emphasize the potential of using these small RNA species as non-invasive biomarkers for the early detection of oral cancerous lesions. Conclusively, we highlight the perspectives and limitations of microRNAs as novel diagnostic tools, as well as therapeutic models.

Diagnostic and Prognostic Value of MicroRNAs in Metastasis and Recurrence of Head and Neck Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

MicroRNAs have been proven to make remarkable differences in the clinical behaviors of head and neck squamous cell carcinoma (HNSCC). This study aims to systematically analyze whether differential expression levels of microRNAs are related to recurrence or metastasis in patients with HNSCC. A comprehensive search of the PubMed, EMBASE, and CENTRAL was conducted up to July 24^th, 2021. Data were collected and combined from studies reporting recurrence-free survival (RFS) of HNSCC patients with high microRNA expression compared to those with low expression. Besides, studies providing necessary data for evaluating the diagnostic value of microRNAs for detecting recurrence and metastasis based on their expression levels were also included and combined. The pooled hazard ratio (HR) value for the outcomes of RFS in 1,093 HNSCC samples from 10 studies was 2.51 (95%CI: 2.13–2.96). A sensitivity of 0.79 (95% CI: 0.72–0.85) and specificity of 0.77 (95%CI: 0.68–0.83) were observed in three studies, of which 93 patients with recurrence and 82 nonrecurrence controls were included, and the area under the curve (AUC) was 0.85 (95% CI: 0.81–0.88). Additionally, high diagnostic accuracy of microRNAs in detecting lymph node metastasis (LNM) was also reported. In conclusion, two panels of microRNAs showed the potential to predict recurrence or diagnose recurrence in HNSCC patients, respectively, which could facilitate prognosis prediction and diagnosis of clinical behaviors in HNSCC patients.

High expression of PDGFA predicts poor prognosis of esophageal squamous cell carcinoma

Platelet-derived growth factor A (PDGFA), the most known member of PDGF family, plays a crucial role in occurrence and progression of different tumors. However, PDGFA expression and its clinical significance in esophageal squamous cell carcinoma (ESCC) are not clear. The present study aimed to assess the expression and prognostic value of PDGFA in ESCC.The Gene Expression Omnibus databases (GSE53625, GSE23400, and GSE67269) and fresh clinical samples were employed for detecting PDGFA messenger RNA expression in ESCC. The associations of PDGFA expression with clinicopathological characteristics were evaluated by chi-square test. Kaplan-Meier analysis and Cox proportional hazard regression model were performed to determine the prognostic value of PDGFA in ESCC patients. PDGFA-related signaling pathways were defined by gene set enrichment analysis based on Gene Expression Omnibus databases.The PDGFA messenger RNA expression was upregulated in ESCC tissues compared with paired adjacent noncancerous tissues (P < .05) and was positively correlated with T stage (P < .05). Kaplan-Meier survival analysis suggested that ESCC patients with high PDGFA expression were associated with poorer overall survival compared to those with low PDGFA expression (P < .05), especially in advanced T stage (P < .05). Cox analyses showed that high expression of PDGFA was an independent predictor for poor prognosis in ESCC patients. Gene set enrichment analysis identified 3 signaling pathways (extracellular matrix receptor interaction, focal adhesion, and glycosaminoglycan biosynthesis chondroitin sulfate) that were enriched in PDGFA high expression phenotype (all P < .01).PDGFA may serve as an oncogene in ESCC and represent an independent molecular biomarker for prognosis of ESCC patients.

MicroRNA-363-3p inhibits tumor cell proliferation and invasion in oral squamous cell carcinoma cell lines by targeting SSFA2

The aim of the present study was to evaluate the expression levels of microRNA (miR)-363-3p and its underlying physiological function in oral squamous cell carcinoma (OSCC). miR-363-3p expression levels were measured in OSCC cell lines using reverse transcription-quantitative PCR. The role of miR-363-3p in OSCC cells was examined using gain-of-function assays in vitro. Cell proliferation was assessed using Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine assays and flow cytometry. Cell migration and invasion were evaluated in wound-healing and Transwell Matrigel assays. In addition, bioinformatics analysis predicted binding sites of miR-363-3p on sperm-specific antigen 2 (SSFA2). Luciferase reporter and RNA pull-down assays were conducted to test whether miR-363-3p interacted with SSFA2. miR-363-3p expression was downregulated in OSCC cell lines compared with that in the normal epithelial cell line (NHOK). Additionally, miR-363-3p overexpression suppressed OSCC cell proliferation, migration and invasion in vitro. SSFA2 was verified as a direct target of miR-363-3p, and SSFA2 overexpression partially counteracted the inhibitory effects of miR-363-3p on cell proliferation, migration and invasion in OSCC cell lines. Thus, miR-363-3p may serve as a tumor suppressor via targeting SSFA2 and may represent a potential therapeutic target for OSCC.

MicroRNAs as Modulators of Oral Tumorigenesis-A Focused Review

Oral cancers constitute the majority of head and neck tumors, with a relatively high incidence and poor survival rate in developing countries. While the five-year survival rates of the oral cancer patients have increased to 65%, the overall survival for advanced stages has been at 27% for the past ten years, emphasizing the necessity for further understanding the etiology of the disease, diagnosis, and formulating possible novel treatment regimens. MicroRNAs (miRNAs), a family of small non-coding RNA, have emerged as master modulators of gene expression in various cellular and biological process. Aberrant expression of these dynamic molecules has been associated with many human diseases, including oral cancers. The deregulated miRNAs have been shown to control various oncogenic processes, including sustaining proliferative signaling, evading growth suppressors, resisting cell death activating invasion and metastasis, and inducing angiogenesis. Hence, the aberrant expression of miRNAs associated with oral cancers, makes them potential candidates for the investigation of functional markers, which will aid in the differential diagnosis, prognosis, and development of novel therapeutic regimens. This review presents a holistic insight into our understanding of the role of miRNAs in regulating various hallmarks of oral tumorigenesis.

LncRNA SNHG17 promotes the progression of oral squamous cell carcinoma by modulating miR-375/PAX6 axis

BACKGROUND

The prognosis of patients with recurrent and/or metastatic oral squamous cell carcinoma (OSCC) remains poor, and its incidence is especially high in developing countries. Multiple long non-coding RNAs (lncRNAs) are recently identified as crucial oncogenic factors or tumor suppressors. This study aimed to probe into the role of lncRNA small nucleolar RNA host gene 17 (SNHG17) on the progression of OSCC.

METHODS

The expression level of SNHG17 in OSCC samples was tested using quantitative real-time polymerase chain reaction (qRT-PCR). Human OSCC cell lines CAL-27 and Tca8113 were used in in vitro studies. Cell counting kit-8 (CCK-8) and BrdU assays were used to assess the effect of SNHG17 on OSCC cell proliferation. Flow cytometry was used to study the effect of SNHG17 on OSCC cell apoptosis. Transwell assay was conducted to detect the effect of SNHG17 on migration and invasion. Moreover, luciferase reporter assay was employed to confirm targeting relationship between miR-375 and SNHG17. Additionally, Western blot was used to observe the regulatory function of SNHG17 on PAX6.

RESULTS

SNHG17 expression in OSCC clinical samples was significantly increased and was correlated with unfavorable pathological indexes. Its overexpression remarkably accelerated proliferation and metastasis of OSCC cells, while reduced apoptosis. Accordingly, knockdown of SNHG17 suppressed the malignant phenotypes of OSCC cells. Overexpression of SNHG17 significantly reduced the expression of miR-375 by sponging it, but enhanced the expression of PAX6.

CONCLUSION

SNHG17 is a sponge of tumor suppressor miR-375 in OSCC, enhances the expression of PAX6 indirectly, and functions as an oncogenic lncRNA.

MicroRNA profile in the squamous cell carcinoma: prognostic and diagnostic roles

Head and neck squamous cell carcinomas (HNSCCs) are human malignancies associated with both genetic and environmental factors. MicroRNAs (miRNAs) as a group of small non-coding RNAs have prominent roles in the development of this kind of cancer. Expressions of several miRNAs have been demonstrated to be increased in HNSCC samples vs. non-malignant tissues. In silico prediction tools and functional analyses have confirmed the function of some miRNAs in the modulation of cancer-associated targets, thus indicating these miRNAs as onco-miRs. Moreover, numerous miRNAs have been down-regulated in HNSCC samples. Their targets mostly enhance cell proliferation or inhibit apoptosis. miRNAs signature has practical implications in the diagnosis, staging, and management of HNSC. Most notably, numerous miRNAs have been shown to alter response of tumor cells to anti-cancer drugs such as cisplatin and doxorubicin. Circulating levels of these small transcripts have been suggested as promising biomarkers for diagnosis of HNSCC. In the present manuscript, we sum up the available literature regarding the miRNAs signature in HNSCC and their role as diagnostic/prognostic biomarkers.

ASC modulates HIF-1α stability and induces cell mobility in OSCC

High-level expression of ASC (Apoptosis-associated speck-like protein containing a CARD) leads to lymph node metastasis in OSCC, but the underlying mechanism remains unclear. Here, we show that HIF-1α participates in ASC-induced metastasis. We identified 195 cell-motion-associated genes that were highly activated in ASC-overexpressed SAS_ASC cells; of them, 14 representative genes were found to be overexpressed in OSCC tissues in our previously reported RNA-seq dataset, OSCC-Taiwan. Nine of the 14 genes were also upregulated in OSCC-TCGA samples. Among the nine genes, RRAS2, PDGFA, and VEGFA, were correlated with poor overall survival of patients in OSCC-TCGA dataset. We further demonstrated that the promoters of these 14 ASC-induced genes contained binding motifs for the transcription-regulating factor, HIF-1α. We observed that ASC interacted with and stabilized HIF-1α in both the cytoplasm and the nucleus under normoxia. Molecules involved in the HIF-1α pathway, such as VHL and PHD2, showed no difference in their gene and protein levels in the presence or absence of ASC, but the expression of HIF-1α-OH, and the ubiquitination of HIF-1α were both decreased in SAS_ASC cells versus SAS_con cells. The migration and invasion activities of SAS_ASC cells were reduced when cells were treated with the HIF-1α synthesis inhibitor, digoxin. Taken together, our results demonstrate that the novel ASC-HIF-1α regulatory pathway contributes to lymph node metastasis in OSCC, potentially suggesting a new treatment strategy for OSCC.

The roles of microRNAs in the stemness of oral cancer cells

Oral cancer (OC), which is the most common form of head and neck cancers, has one of the lowest (~50%) overall 5-year survival rates. The main reasons for this high mortality rate are diagnosis of OC in advanced stages in most patients and spread to distant organs via lymph node metastasis. Many studies have shown that a small population of cells within the tumor plays vital roles in the initiation, progression, and metastasis of the tumor, resistance to chemotherapeutic agents, and recurrence. These cells, identified as cancer stem cells (CSCs), are the main reasons for the failure of current treatment modalities. Deregulated expressions of microRNAs are closely related to tumor prognosis, metastasis and drug resistance. In addition, microRNAs play important roles in regulating the functions of CSCs. Until now, the roles of microRNAs in the acquisition and maintenance of OC stemness have not been elucidated in detail yet. Here in this review, we summarized significant findings and the latest literature to better understand the involvement of CSCs in association with dysregulated microRNAs in oral carcinogenesis. Possible roles of these microRNAs in acquisition and maintenance of CSCs features during OC pathogenesis were summarized.

microRNAs in oral cancer: Moving from bench to bed as next generation medicine

Oral cancer is the thirteenth most common cancer in the world, with India contributing to 33% of the global burden. Lack of specific non-invasive markers, non-improvement in patient survival and tumor recurrence remain a major clinical challenge in oral cancer. Epigenetic regulation in the form of microRNAs (miRs) that act as tumor suppressor miRs or oncomiRs has gained significant momentum with the advancement in the field, suggesting the potential for clinical application of miRs in oral cancer. The current review of literature identified miR-21, miR-27a(-3p), miR-31, miR-93, miR-134, miR-146, miR-155, miR-196a, miR-196b, miR-211, miR-218, miR-222, miR-372 and miR-373 to be up-regulated and let-7a, let-7b, let-7c, let-7d, let-7e, let-7f, let-7g, let-7i, miR-26a, miR-99a-5p, miR-137, miR-139-5p, miR-143-3p, miR-184 and miR-375 to be down-regulated in oral cancer. Mechanistic studies have uncovered several miRs that are deregulated at varying levels and in different stages of oral cancer progression, thus providing clinical utility in better diagnosis as well as usefulness in prognosis by identifying patients with poor prognosis or stratifying patients based on responsiveness to chemo- and radio-therapy. Lastly, exogenous modulation of miR expression using miRNA-based drugs in combination with first-line agents may be adopted as a new therapeutic modality to treat oral cancer. Knowledge of miRs and their involvement in key molecular processes, clinical association, responsiveness to therapy and clinical advancement may highlight additional avenues in order to improve patient morbidity and mortality. Furthermore, combinatorial approaches with miR-therapy may be efficacious in oral cancer.

Overexpression of β-Adrenergic Receptors and the Suppressive Effect of β2-Adrenergic Receptor Blockade in Oral Squamous Cell Carcinoma

PURPOSE

The purpose of this project was to investigate the expression of β-adrenergic receptors in oral squamous cell carcinoma (OSCC) and the tumor suppressive activity of β₂-adrenergic receptor (β₂-AR) blockade.

MATERIALS AND METHODS

Samples of 15 normal oral mucosal epithelial tissues, 60 surgically resected OSCC tissues, and 60 adjacent para-carcinoma tissues were collected. The expression of β₁-adrenergic receptor and β₂-AR was detected by real-time quantitative polymerase chain reaction and the Western blot test. SCC9 and Cal27 cell lines and primary OSCC cells also were included and treated with ICI-118,551 (MedChemExpress, Monmouth Junction, NJ), a selective β₂-AR blocker. In addition, the Cal27 cell line was treated with propranolol (a nonselective β-adrenergic receptor blocker) to verify the suppressive effect of β₂-AR blockade. For in vivo assays, Cal27 cells were subcutaneously injected in the tongue flank of nude mice. ICI-118,551 was orally administered to the mice in the treatment group daily. High-throughput sequencing was used to screen for changes in gene expression.

RESULTS

Real-time quantitative polymerase chain reaction and the Western blot test both showed that β₁-adrenergic receptor and β₂-AR were overexpressed in OSCC tissues and cells. A relationship was found between β₂-AR and a more advanced clinical stage, as well as preoperative lymphatic metastasis. After treatment with ICI-118,551 or propranolol, the capacities for proliferation, invasion, and metastasis of OSCC cells were significantly inhibited. Tumor size was significantly different between the ICI-118,551 and control groups. The survival time in the ICI-118,551 group also was prolonged significantly. Moreover, high-throughput sequencing identified 19 affected signaling pathways, including mitogen-activated protein kinase and PI3K-Akt. We confirmed a significant change to the expression of several genes closely related to the progression of cancer.

CONCLUSION

This study showed that β₂-AR is related to a more advanced clinical stage and preoperative lymphatic metastasis. Additionally, a β₂-AR blocker has a significant suppressive effect in OSCC.

CREB1-induced miR-1204 promoted malignant phenotype of glioblastoma through targeting NR3C2

Background

Glioblastoma (GBM) is a subclass of brain malignancy with unsatisfactory prognosis. MicroRNAs (miRNAs) are a group of non-coding RNAs (ncRNAs) that exert key function on tumorigenesis and tumor development.

Purposes

The purpose of this work was to unravel the biological behavior and mechanism of miR-1204 in GBM.

Methods

Expressions of miR-1204, NR3C2 and CREB1 were detected by RT-qPCR and western blot. Proliferation and apoptosis of GBM cells were detected by CCK-8, colony formation, caspase-3 activity and TUNEL assays. Molecular interplays were examined by ChIP, RIP, and luciferase reporter assays.

Results

MiR-1204 level was elevated in GBM cell lines. Functionally, miR-1204 aggravated cell proliferation whereas suppressed cell apoptosis in GBM cells. Mechanistically, cAMP Responsive Element Binding Protein 1 (CREB1) bound to the promoter of miR-1204 and activated the transcription of miR-1204. Furthermore, miR-1204 targeted and inhibited Nuclear receptor subfamily 3 group C member 2 (NR3C2), a tumor suppressor gene in GBM cells. Rescue assays indicated that NR3C2 participated in the regulation of miR-1204 on the malignant phenotype of GBM cells.

Conclusions

We observed for the first time that CREB1-induced miR-1204 promoted malignant phenotype of GBM through targeting NR3C2, indicating that miR-1204 acted as a novel oncogenic miRNA in GBM.

Prospective applications of microRNAs in oral cancer

MicroRNAs (miRNAs) are non-coding RNA molecules that are generally encoded by endogenous genes and exert suppressive effects on post-transcriptional regulation of their target genes by translation repression or degradation of mRNA. This subsequently mediates activation or blocking of downstream signaling pathways associated with oral malignancies. Aberrant levels of certain miRNAs have been identified in cell experiments, clinical carcinomatous specimens, saliva, serum or plasma samples of patients with oral malignancies. miRNAs are associated with multiple aspects of oral cancer, including tumor growth, cellular proliferation, apoptosis, migration, invasion, metastasis, glycometabolism, radiosensitivity and chemosensitivity. miRNAs have the potential to be used in clinical applications as minimally invasive or non-invasive tools for early diagnosis and prognosis by the detection of serum, plasma and saliva levels, and may provide a new ancillary or additional reference index of traditional pathological grading and clinical staging. Furthermore, miRNAs may be used as prognostic biomarkers or targets for novel therapies for oral cancer.

Characterizing methylation regulated miRNA in carcinoma of the human uterine cervix

Gene regulatory mechanisms determine the multistep carcinogenesis process. Two aspects of epigenetics are microRNA (miRNAs) and DNA methylation that regulate distinct biological mechanisms such as metastasis, apoptosis cell proliferation and induction of senescence. Although critical, the interplay between these two epigenetic mechanisms is yet to be completely understood, particularly in cervical cancer. To study the DNA methylation regulation of miRNAs and its potential role in cervical cancer, we investigated the differential methylation pattern of two candidate miRNAs (miR-375 and miR-196a-1) during cervical cancer progression against normal cervical epithelium (NCE) by bisulfite DNA sequencing. miR-375 and miR-196a-1 were hypermethylated in Squamous Cell Carcinoma (SCC) against NCE and Cervical Intra-Epithelial Neoplasia (CIN) (p < 0.05). Treatment with demethylating agent reactivated the miR-375 and miR-196a-1 expression in SiHa, HeLa and CaSki cells. In vitro artificial methylation by M.SssI followed by dual luciferase assay confirmed miR-375 and miR-196a-1 as methylation regulated miRNAs (P < 0.05). miR-375 and miR-196a-1 expression levels were negatively correlated with methylation levels in clinical specimens. We further identified Replication Factor C Subunit 3 (RFC3) and High Mobility Group AT-Hook 1 (HMGA1) as targets of miR-375 and miR-196a-1 respectively by dual luciferase reporter assay. Our analysis indicates that miR-375 and miR-196a-1 are DNA methylation regulated miRNAs whose deregulation may facilitate pathophysiology of cervical cancer.

Invasion-Related Factors as Potential Diagnostic and Therapeutic Targets in Oral Squamous Cell Carcinoma-A Review

It is well recognized that the presence of cervical lymph node metastasis is the most important prognostic factor in oral squamous cell carcinoma (OSCC). In solid epithelial cancer, the first step during the process of metastasis is the invasion of cancer cells into the underlying stroma, breaching the basement membrane (BM)—the natural barrier between epithelium and the underlying extracellular matrix (ECM). The ability to invade and metastasize is a key hallmark of cancer progression, and the most complicated and least understood. These topics continue to be very active fields of cancer research. A number of processes, factors, and signaling pathways are involved in regulating invasion and metastasis. However, appropriate clinical trials for anti-cancer drugs targeting the invasion of OSCC are incomplete. In this review, we summarize the recent progress on invasion-related factors and emerging molecular determinants which can be used as potential for diagnostic and therapeutic targets in OSCC.

MicroRNA meta-signature of oral cancer: evidence from a meta-analysis

AIM

It was the aim of the study to identify commonly deregulated miRNAs in oral cancer patients by performing a meta-analysis of previously published miRNA expression profiles in cancer and matched normal non-cancerous tissue in such patients.

MATERIAL AND METHODS

Meta-analysis included seven independent studies analyzed by a vote-counting method followed by bioinformatic enrichment analysis.

RESULTS

Amongst seven independent studies included in the meta-analysis, 20 miRNAs were found to be deregulated in oral cancer when compared with non-cancerous tissue. Eleven miRNAs were consistently up-regulated in three or more studies (miR-21-5p, miR-31-5p, miR-135b-5p, miR-31-3p, miR-93-5p, miR-34b-5p, miR-424-5p, miR-18a-5p, miR-455-3p, miR-450a-5p, miR-21-3p), and nine were down-regulated (miR-139-5p, miR-30a-3p, miR-376c-3p, miR-885-5p, miR-375, miR-486-5p, miR-411-5p, miR-133a-3p, miR-30a-5p). The meta-signature of identified miRNAs was functionally characterized by KEGG enrichment analysis. Twenty-four KEGG pathways were significantly enriched, and TGF-beta signaling was the most enriched signaling pathway. The highest number of meta-signature miRNAs was involved in the sphingolipid signaling pathway. Natural killer cell-mediated cytotoxicity was the pathway with most genes regulated by identified miRNAs. The rest of the enriched pathways in our miRNA list describe different malignancies and signaling.

CONCLUSIONS

The identified miRNA meta-signature might be considered as a potential battery of biomarkers when distinguishing oral cancer tissue from normal, non-cancerous tissue. Further mechanistic studies are warranted in order to confirm and fully elucidate the role of deregulated miRNAs in oral cancer.