MicroRNA-200c attenuates tumour growth and metastasis of presumptive head and neck squamous cell carcinoma stem cells

MicroRNA-200c in Cancer Generation, Invasion, and Metastasis

MicroRNA-200c (miR-200c) is increasingly recognized as a crucial small RNA molecule that plays a significant and multifaceted role in the complex processes of tumor development, invasion, and metastasis across various types of cancers. Recent studies have compellingly demonstrated that miR-200c exerts its influence on tumor biology by meticulously regulating a range of critical processes, including cell proliferation, apoptosis, epithelial-mesenchymal transition (EMT), and cell migration, all of which are essential for the progression and aggressiveness of tumors. This comprehensive review aims to summarize the expression characteristics and functional implications of miR-200c across a diverse array of tumor types, delving into its potential utility as both a biomarker for early detection and a therapeutic target in the realm of cancer treatment. By synthesizing current research findings and insights, we aspire to provide valuable information that could significantly enhance early diagnostic capabilities and inform the strategic development of targeted therapy approaches in oncology.

The role of MiRNA-34 family in different signaling pathways and its therapeutic options

MiRNAs are short non-coding RNA molecules that have been shown to affect a vast number of genes at the post-transcriptional level, hence regulating several signaling pathways. Because the miRNA-34 family regulates a number of different signaling pathways, including those linked to cancer, the immune system, metabolism, cellular structure, and neurological disorders, it has garnered a great deal of attention from researchers. Members of the miRNA-34 family have been shown to inhibit tumors in a variety of cancer types. This family is also important for obesity, the cardiovascular system, and glycolysis. It's interesting to note that the miRNA-34 family is known to play a role in major depressive disorder, schizophrenia, Parkinson's disease (PD), adverse childhood experiences or trauma, regulation of stress responses, Alzheimer's disease (AD), and stress-related psychatric conditions. In this review, the expected targets of the miRNA-34 family are presented alongside the well-established targets identified by pathway analysis. Furthermore, the therapeutic potential of this miRNA family will be discussed.

Extracellular Vesicle microRNAs as Possible Liquid Biopsy Markers in HNSCC-A Longitudinal, Monocentric Study

BACKGROUND

Biomarkers for HNSCC are still lacking. Biomolecules obtained via liquid biopsy are being investigated for diagnosis, prognosis, and therapy monitoring, including extracellular vesicles (EVs) and EV-cargo, e.g., proteins, RNA, and microRNA. This study aims to understand localization-dependent EV-microRNA expression in blood sera, their dynamics over time (12 months FU), and insights into their potential in diagnostics and therapy monitoring.

METHODS

Via liquid biopsy, blood serum was taken from 50 patients with HNSCC and 16 controls. Extracellular vesicles were isolated from serum by precipitation, and the contained microRNA-21, -1246, -200c, -let-7a, -181a, and -26a were amplified by reverse transcription and determined with real-time PCR. Expression ratios (HNSCC to healthy controls) were collated with the patients' clinical parameters. A second liquid biopsy was carried out avg. 12 months later in the tumor aftercare. A sub-analysis with the Oropharynx subsite was implemented.

RESULTS

EV-mir-21, -let-7a, and -181a were 2.5-3-fold higher expressed in HPV/p16+ than in HPV/p16- HNSCC. Different expressions of EV-mir-181a and -26a could be demonstrated depending on the therapy modality.

CONCLUSIONS

EV-microRNA could be a promising biomarker in the diagnosis and therapy monitoring of HNSCC. A systematic comparison of EV- and tissue microRNA expression in different HNSCC-subsites is needed.

IP3R1 dysregulation via mir-200c-3p/SSFA2 axis contributes to taxol resistance in head and neck cancer

Head and neck cancer (HNC) is the sixth most common malignancy worldwide. Although current modalities offer a wide variety of therapy choices, head and neck carcinoma has poor prognosis due to its diagnosis at later stages and development of resistance to current therapeutic tools. In the current study, we aimed at exploring the roles of miR-200c-3p during head and neck carcinogenesis and acquisition of taxol resistance. We analyzed miR-200c-3p levels in HNC clinical samples and cell lines using quantitative real-time polymerase chain reaction and evaluated the effects of differential miR-200c-3p expression on cancer-related cellular phenotypes using in-vitro tools. We identified and characterized a direct target of miR-200c-3p using in-silico tools, luciferase and various in-vitro assays. We investigated potential involvement of miR-200c-3p/SSFA2 axis in taxol resistance in-vitro. We found miR-200c-3p expression as significantly downregulated in both HNC tissues and cells compared to corresponding controls. Ectopic miR-200c-3p expression in HNC cells significantly inhibited cancer-related phenotypes such as viability, clonogenicity, migration, and invasion. We, then, identified SSFA2 as a direct target of miR-200c-3p and demonstrated that overexpression of SSFA2 induced malignant phenotypes in HNC cells. Furthermore, we found reduced miR-200c-3p expression in parallel with overexpression of SSFA2 in taxol resistant HNC cells compared to parental sensitive cells. Both involved in intracellular cytoskeleton remodeling, we found that SSFA2 works collaboratively with IP3R1 to modulate resistance to taxol in HNC cells. When considered collectively, our results showed that miR-200c-3p acts as a tumor suppressor microRNA and targets SSFA2/IP3R1 axis to sensitize HNC cells to taxol.

Pharmacological impact of microRNAs in head and neck squamous cell carcinoma: Prevailing insights on molecular pathways, diagnosis, and nanomedicine treatment

Head and neck squamous cell carcinoma is a disease that most commonly produce tumours from the lining of the epithelial cells of the lips, larynx, nasopharynx, mouth, or oro-pharynx. It is one of the most deadly forms of cancer. About one to two percent of all neo-plasm-related deaths are attributed to head and neck squamous cell carcinoma, which is responsible for about six percent of all cancers. MicroRNAs play a critical role in cell proliferation, differentiation, tumorigenesis, stress response, triggering apoptosis, and other physiological process. MicroRNAs regulate gene expression and provide new diagnostic, prognostic, and therapeutic options for head and neck squamous cell carcinoma. In this work, the role of molecular signaling pathways related to head and neck squamous cell carcinoma is emphasized. We also provide an overview of MicroRNA downregulation and overexpression and its role as a diagnostic and prognostic marker in head and neck squamous cell carcinoma. In recent years, MicroRNA nano-based therapies for head and neck squamous cell carcinoma have been explored. In addition, nanotechnology-based alternatives have been discussed as a promising strategy in exploring therapeutic paradigms aimed at improving the efficacy of conventional cytotoxic chemotherapeutic agents against head and neck squamous cell carcinoma and attenuating their cytotoxicity. This article also provides information on ongoing and recently completed clinical trials for therapies based on nanotechnology.

Molecular insights into the role of electronic cigarettes in oral carcinogenesis

Electronic cigarette (EC) usage or vaping has seen a significant rise in recent years across various parts of the world. They have been publicized as a safe alternative to smoking; however, this is not supported strongly by robust research evidence. Toxicological analysis of EC liquid and aerosol has revealed presence of several toxicants with known carcinogenicity. Oral cavity is the primary site of exposure of both cigarette smoke and EC aerosol. Role of EC in oral cancer is not as well-researched as that of traditional smoking. However, several recent studies have shown that it can lead to a wide range of potentially carcinogenic molecular events in oral cells. This review delineates the oral carcinogenesis potential of ECs at the molecular level, providing a summary of the effects of EC usage on cancer therapy resistance, cancer stem cells (CSCs), immune evasion, and microbiome dysbiosis, all of which may lead to increased tumor malignancy and poorer patient prognosis. This review of literature indicates that ECs may not be as safe as they are perceived to be, however further research is needed to definitively determine their oncogenic potential.

In silico analysis reveals hypoxia-induced miR-210-3p specifically targets SARS-CoV-2 RNA

Human coronaviruses (HCoVs) until the emergence of SARS in 2003 were associated with mild cold and upper respiratory tract infections. The ongoing pandemic caused by SARS-CoV-2 has enhanced the potential for infection and transmission as compared to other known members of this family. MicroRNAs (miRNA) are 21-25 nucleotides long non-coding RNA that bind to 3' UTR of genes and regulate almost every aspect of cellular function. Several human miRNAs have been known to target viral genomes, mostly to downregulate their expression and sometimes to upregulate also. In some cases, host miRNAs could be sequestered by the viral genome to create a condition for favourable virus existence. The ongoing SARS CoV-2 pandemic is unique based on its transmissibility and severity and we hypothesised that there could be a unique mechanism for its pathogenesis. In this study, we exploited in silico approach to identify human respiratory system-specific miRNAs targeting the viral genome of three highly pathogenic HCoVs (SARS-CoV-2 Wuhan strain, SARS-CoV, and MERS-CoV) and three low pathogenic HCoVs (OC43, NL63, and HKU1). We identified ten common microRNAs that target all HCoVs studied here. In addition, we identified unique miRNAs which targeted specifically one particular HCoV. miR-210-3p was the single unique lung-specific miRNA, which was found to target the NSP3, NSP4, and NSP13 genes of SARS-CoV-2. Further miR-210-NSP3, miR-210-NSP4, and miR-210-NSP13 SARS-CoV-2 duplexes were docked with the hAGO2 protein (PDB ID 4F3T) which showed Z-score values of -1.9, -1.7, and -1.6, respectively. The role of miR-210-3p as master hypoxia regulator and inflammation regulation may be important for SARS-CoV-2 pathogenesis. Overall, this analysis advocates that miR-210-3p be investigated experimentally in SARS-CoV-2 infection.Communicated by Ramaswamy H. Sarma.

MicroRNA expression profiling of endocrine sensitive and resistant breast cancer cell lines

Background

Methods

Results

Conclusions

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Around 50–60% of microRNAs were significantly differentially expressed between ER- and ER + breast cancer cell lines.

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Transfection of miR-200c-3p mimic into ER -ve cells induced MET and reduced cell motility.

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Transfecting of miR-449a inhibitor into ER -ve cells reduced cell invasion but did not induce EMT.

Promising Biomarkers in Head and Neck Cancer: The Most Clinically Important miRNAs

Head and neck cancers (HNCs) comprise a heterogeneous group of tumors that extend from the oral cavity to the upper gastrointestinal tract. The principal etiologic factors for oral tumors include tobacco smoking and alcohol consumption, while human papillomavirus (HPV) infections have been accused of a high incidence of pharyngeal tumors. Accordingly, HPV detection has been extensively used to categorize carcinomas of the head and neck. The diverse nature of HNC highlights the necessity for novel, sensitive, and precise biomarkers for the prompt diagnosis of the disease, its successful monitoring, and the timely prognosis of patient clinical outcomes. In this context, the identification of certain microRNAs (miRNAs) and/or the detection of alterations in their expression patterns, in a variety of somatic fluids and tissues, could serve as valuable biomarkers for precision oncology. In the present review, we summarize some of the most frequently studied miRNAs (including miR-21, -375, -99, -34a, -200, -31, -125a/b, -196a/b, -9, -181a, -155, -146a, -23a, -16, -29, and let-7), their role as biomarkers, and their implication in HNC pathogenesis. Moreover, we designate the potential of given miRNAs and miRNA signatures as novel diagnostic and prognostic tools for successful patient stratification. Finally, we discuss the currently ongoing clinical trials that aim to identify the diagnostic, prognostic, or therapeutic utility of miRNAs in HNC.

Butylidenephthalide Abrogates the Snail-Induced Cancer Stemness in Oral Carcinomas

Oral cancer is one of the most common cancers worldwide, especially in South Central Asia. It has been suggested that cancer stem cells (CSC) play crucial roles in tumor relapse and metastasis, and approaches to target CSC may lead to promising results. Here, aldehyde dehydrogenase 1 (ALDH1) and CD44 were utilized to isolate CSCs of oral cancer. Butylidenephthalide, a bioactive phthalide compound from Angelica sinensis, was tested for its anti-CSC effects. MTT assay showed that a lower concentration of butylidenephthalide was sufficient to inhibit the proliferation of patient-derived ALDH1⁺/CD44⁺ cells without affecting normal cells. Administration of butylidenephthalide not only reduced ALDH1 activity and CD44 expression, it also suppressed the migration, invasion, and colony formation abilities of ALDH1⁺/CD44⁺ cells using a transwell system and clonogenic assay. A patient-derived xenograft mouse model supported our in vitro findings that butylidenephthalide possessed the capacity to retard tumor development. We found that butylidenephthalide dose-dependently downregulated the gene and protein expression of Sox2 and Snail. Our results demonstrated that overexpression of Snail in ALDH1^-/CD44^- (non-CSCs) cells induced the CSC phenotypes, whereas butylidenephthalide treatment successfully diminished the enhanced self-renewal and propagating properties. In summary, this study showed that butylidenephthalide may serve as an adjunctive for oral cancer therapy.

Liquid Biopsy in Squamous Cell Carcinoma of the Esophagus and of the Head and Neck

Squamous cell carcinomas of the esophagus (ESCC) and of the head and neck (HNSCC) are two neoplasms that share common risk factors and have the same embryological origin, but a very different prognosis, the 5-year survival of HNSCC being almost double (40–50%) compared to the 5-year survival of ESCC (20%). Current guidelines emphasize the importance of screening for ESCC in patients diagnosed with head and neck cancers. A liquid biopsy is a novel tool for diagnosis, prognostic stratification, and personalized therapy. Liquid biopsy biomarkers for these two malignancies could help both their early detection, facilitate residual disease identification, and provide prognosis information. The present systematic review of the literature was aimed at describing the liquid biopsy biomarkers present in these two malignancies, with an emphasis on potential clinical applications.

The Role of MicroRNA in Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) include epithelial tumors arising in the structures of aerodigestive tract such as oral and nasal cavity, pharynx, larynx, paranasal sinuses, and local lymph nodes. HNSCC is the sixth most common cancer worldwide, and its prognosis is very poor. MicroRNAs (miRNAs) are small single stranded noncoding RNAs which are about 19-25 nucleotides involved in cell proliferation, development, differentiation and metastasis. It is believed that miRNA alterations correlate with initiation and progression of cancer cell proliferation or inhibition of tumorigenesis especially in development, progression, and metastasis of HNSCC. Altered expression of miRNAs could be novel molecular biomarkers for the diagnosis and prognosis of HNSCC. Despite the advances in cancer treatment, the mortality rate of HNSCC is still high. The potential application of miRNAs for cancer therapy has been demonstrated in many studies. In this review, we discuss the very recent studies on different aspects of miRNA dysregulation with their clinical significance and miRNA-based therapy.

Carbon-Ion Beam Irradiation and the miR-200c Mimic Effectively Eradicate Pancreatic Cancer Stem Cells Under in vitro and in vivo Conditions

Purpose

The study investigated the molecular mechanisms that killed pancreatic cancer cells, including cancer stem cells (CSCs), by carbon ion beam irradiation alone or in combination with miRNA-200c under in vitro and in vivo conditions.

Methods

Human pancreatic cancer (PC) cells, PANC1 and PK45, were treated with carbon-ion beam irradiation alone or in combination with microRNA-200c (miR-200c) mimic. Cell viability assay, colony and spheroid formation assay, quantitative real-time PCR analysis of apoptosis-, autophagy-, and angiogenesis-related gene expression, xenograft tumor control and histopathological analyses were performed.

Results

The cell viability assay showed that transfection of the miRNA-200c (10 nM) mimic into pancreatic CSC (CD44+/ESA+) and non-CSC (CD44-/ESA-) significantly suppressed proliferation of both types of cell populations described above. Combining carbon-ion beam irradiation with the miRNA-200c mimic significantly reduced the colony as well as spheroid formation abilities compared to that observed with the treatment of carbon-ion beam alone or X-ray irradiation combined with the miRNA-200c mimic. Moreover, the combination of carbon ion beam irradiation and miRNA-200c mimic increased the expression of apoptosis-related gene BAX, autophagy-related genes Beclin-1 and p62, addition of gemcitabine (GEM) further enhanced the expression of these genes. In vivo data showed that carbon-ion beam irradiation in combination with the miRNA-200c mimic effectively suppressed xenograft tumor growth and significantly induced tumor necrosis and cavitation.

Conclusion

The combination of miRNA-200c mimic and carbon ion beam irradiation may be powerful radiotherapy that significantly kills pancreatic cancer cells containing CSCs and enhances the effect of carbon-ion beam irradiation compared to carbon-ion beam irradiation alone.

The Role of Non-Coding RNAs in the Regulation of the Proto-Oncogene MYC in Different Types of Cancer

Alterations in the expression level of the MYC gene are often found in the cells of various malignant tumors. Overexpressed MYC has been shown to stimulate the main processes of oncogenesis: uncontrolled growth, unlimited cell divisions, avoidance of apoptosis and immune response, changes in cellular metabolism, genomic instability, metastasis, and angiogenesis. Thus, controlling the expression of MYC is considered as an approach for targeted cancer treatment. Since c-Myc is also a crucial regulator of many cellular processes in healthy cells, it is necessary to find ways for selective regulation of MYC expression in tumor cells. Many recent studies have demonstrated that non-coding RNAs play an important role in the regulation of the transcription and translation of this gene and some RNAs directly interact with the c-Myc protein, affecting its stability. In this review, we summarize current data on the regulation of MYC by various non-coding RNAs that can potentially be targeted in specific tumor types.

Emerging Role of MicroRNA-200 Family in Dentistry

MicroRNAs (miRNAs) are endogenous non-coding RNAs ~22 nucleotides in length, which have been shown to participate in various biological processes. As one of the most researched miRNAs, the miR-200 family has been found to regulate several factors that are associated with the epithelial to mesenchymal transition (EMT) and cancer stem cells (CSCs) behavior. In this review, we briefly summarize the background of the miR-200 family and their implication in various dental diseases. We focus on the expression changes, biological functions, and clinical significance of the miR-200 family in oral cancer; periodontitis; oral potentially malignant disorder; gingival overgrowth; and other periodontal diseases. Additionally, we discuss the use of the miR-200 family as molecular biomarkers for diagnosis, prognostic, and therapeutic application.

MicroRNAs in head and neck squamous cell carcinoma: a possible challenge as biomarkers, determinants for the choice of therapy and targets for personalized molecular therapies

Head and neck squamous cell carcinoma (HNSCC) are referred to a group of heterogeneous cancers that include structures of aerodigestive tract such as oral and nasal cavity, salivary glands, oropharynx, pharynx, larynx, paranasal sinuses, and local lymph nodes. HNSCC is characterized by frequent alterations of several genes such as TP53, PIK3CA, CDKN2A, NOTCH1, and MET as well as copy number increase in EGFR, CCND1, and PIK3CA. These genomic alterations play a role in terms of resistance to chemotherapy, molecular targeted therapy, and prediction of patient outcome. MicroRNAs (miRNAs) are small single-stranded noncoding RNAs which are about 19-25 nucleotides. They are involved in the tumorigenesis of HNSCC including dysregulation of cell survival, proliferation, cellular differentiation, adhesion, and invasion. The discovery of the stable presence of the miRNAs in all human body made them attractive biomarkers for diagnosis and prognosis or as targets for novel therapeutic ways, enabling personalized treatment for HNSCC. In recent times the number of papers concerning the characterization of miRNAs in the HNSCC tumorigenesis has grown a lot. In this review, we discuss the very recent studies on different aspects of miRNA dysregulation with their clinical significance and we apologize for the many past and most recent works that have not been mentioned. We also discuss miRNA-based therapy that are being tested on patients by clinical trials.

Profiling changes in microRNAs of immature dendritic cells differentiated from human monocytes

MicroRNAs (miRNAs) critically impact a wide array of eukaryotic developmental and physiologic processes through post-transcriptional gene silencing. In this study, we employed miRNA array and investigated in vitro the miRNA profile of immature dendritic cells (iDCs) derived from monocytes isolated from human venous blood. Our results showed that there were 379 miRNAs which were detectable in both monocytes and iDCs among the 856 miRNAs assayed, of which 155 miRNAs were detectable in monocytes while 224 miRNAs were detectable in iDCs. There were 103 miRNAs differentially expressed which could be relevant to the differentiation of iDCs from human monocytes. Sixty-two out of 103 miRNAs were upregulated whereas 41 miRNAs were downregulated. Of particular interest were the tremendous upregulation of miR122a and the downregulation of miR200c in iDCs. In addition, it was found that the strikingly downregulated miRNAs in iDCs also included miR-335, miR-514, miR-509, miR-31, miR-442b, miR-1, miR-199a, miR-203, miR-363 and miR-489 whereas the upregulation of miR-210, miR-155, miR-126, miR-139, miR-452, miR-19a, miR-25 and miR-181d were remarkable. Our results revealed a profile change of miRNAs when human iDCs were differentiated from monocytes as a result of in vitro stimulation with relevant cytokines.

Metabolism, absorption, and anti-cancer effects of sulforaphane: an update

Cancer is one of the most devastating diseases, and recently, a variety of natural compounds with preventive effects on cancer developments have been reported. Sulforaphane (SFN) is a potent anti-cancer isothiocyanate originating from Brassica oleracea (broccoli). SFN, mainly metabolized via mercapturic acid pathway, has high bioavailability and absorption. The present reviews mainly discussed the metabolism and absorption of SFN and newly discovered mechanistic understanding recent years for SFN's anti-cancer effects including promoting autophagy, inducing epigenetic modifications, suppressing glycolysis and fat metabolism. Moreover, its inhibitory effects on cancer stem cells and synergetic effects with other anti-cancer agents are also reviewed along with the clinical trials in this realm.

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.

Salivary protein candidates for biomarkers of oral disorders in alcohol and tobacco dependents

OBJECTIVES

To evaluate the oral condition of alcohol and tobacco dependents and identify salivary protein candidates for biomarkers of oral disorders.

SUBJECTS AND METHODS

Thirty-three male volunteers were evaluated for alcohol abuse rehabilitation; nine were selected for proteomic analysis. Intraoral examination was performed, and non-stimulated saliva was collected. Salivary proteins were extracted and processed for analysis. A list of proteins identified in saliva was generated from the database and manually revised, obtaining the total number of candidate biomarkers for oral disorders.

RESULTS

The mean age (n = 33) was 42.94 ± 8.61 years. Fourteen (42.4%) subjects presented with 23 oral mucosa changes, and 31 (94%) had dental plaque. A total of 282 proteins were found in saliva (n = 9), of which 26 were identified as candidates for biomarkers of oral disorders. After manual review, 21 proteins were selected. The highest number of candidates for biomarkers was associated with carcinoma of head and neck (n = 10), nasopharyngeal carcinoma (n = 6), and periodontal disease (n = 6).

CONCLUSION

Alcohol and tobacco dependents showed gingival inflammation, and less than half of them showed oral mucosa changes. Twenty-one protein candidates for biomarkers of oral disorders were identified in saliva. The two major oral disorders in number of candidates for biomarkers were head and neck cancer and periodontal disease.

LINC00963 Promotes Cancer Stemness, Metastasis, and Drug Resistance in Head and Neck Carcinomas via ABCB5 Regulation

Accumulating studies have indicated that long non-coding RNAs (lncRNAs) participate in the regulation of cancer stem cells (CSCs), which are crucial in tumor initiation, metastasis, relapse, and therapy resistance. In the current study, RT-PCR analysis was employed to evaluate the expression of LINC00963 in tumor tissues and oral CSCs. Stemness phenotypes and the expression of CSCs markers in oral cancer cells transfected with sh-LINC00963 were examined. Our results showed that the expression of the lncRNA LINC00963 was up-regulated in oral cancer tissues and CSCs. We found that the downregulation of LINC00963 inhibited CSC hallmarks, such as migration, invasion and colony formation capacity. Moreover, suppression of LINC00963 reduced the activity of stemness marker ALDH1, the percentage of self-renewal, chemoresistance and the expression of multidrug-resistance transporter ABCB5. Most importantly, we demonstrated that knockdown of LINC00963 decreased self-renewal, invasion and colony formation ability via ABCB5. Analysis of TCGA (the Cancer Genome Atlas) datasets suggested that the level of LINC00963 was positively correlated with the expression of the cancer stemness markers (Sox2 and CD44) and drug resistance markers (ABCG2 and ABCB5). Altogether, our results showed that suppression of LINC00963 may be beneficial to inhibit chemoresistance and cancer relapse in oral cancer patients.

MicroRNAs as Theranostics Targets in Oral Carcinoma Stem Cells

Oral cancer belongs to head and neck squamous cell carcinoma and has been recognized as one of the most prevalent malignancies worldwide. Recent studies have suggested that cancer stem cells (CSCs) may participate in tumor initiation, metastasis and even recurrence, so the regulation of CSCs has drawn significant attention over the past decade. Among various molecules that are associated with CSCs, non-coding RNAs (ncRNAs) have been indicated as key players in the acquisition and maintenance of cancer stemness. In addition, accumulating studies have shown that the aberrant expression of these ncRNAs may serve as surrogate diagnostic markers or even therapeutic targets for cancer treatment. The current study reviews the previous work by us and others to summarize how these ncRNAs affect oral cancer stemness and their potential theranostic applications. A better understanding of the implication of these ncRNAs in oral tumorigenesis will facilitate the translation of basic ncRNA research into clinical application in the future.

Identification of miRNAs correlating with stage and progression of colorectal cancer

Aim: miRNAs control biological processes that are implicated in carcinogenesis, and have been researched as potential biomarkers for colorectal cancer (CRC). The aim of the current study was to evaluate the miRNA expression profile in CRC patients to determine their potential to be used as biomarkers in the disease. Materials & methods: Total 47 tissues and their matched marginal tissues, as control group, were obtained from CRC patients. The transcript levels of a selected panel of 15 cancer-associated miRNAs were quantified via real-time gene expression method. Results: miR-155, miR130a, miR-181b, miR-196a, miR-200c and miR-224 were significantly upregulated, while miR122, miR-132, miR-203b, miR330, miR-323, miR-378a-3p and miR-598 we significantly downregulated in CRC. Conclusion: We identified a panel of miRNAs that may be involved in the etiology and pathogenesis of CRC, and may be used for novel diagnostic and therapeutic strategies.

Role of miRNA-Regulated Cancer Stem Cells in the Pathogenesis of Human Malignancies

Recent biomedical discoveries have revolutionized the concept and understanding of carcinogenesis, a complex and multistep phenomenon which involves accretion of genetic, epigenetic, biochemical, and histological changes, with special reference to MicroRNAs (miRNAs) and cancer stem cells (CSCs). miRNAs are small noncoding molecules known to regulate expression of more than 60% of the human genes, and their aberrant expression has been associated with the pathogenesis of human cancers and the regulation of stemness features of CSCs. CSCs are the small population of cells present in human malignancies well-known for cancer resistance, relapse, tumorigenesis, and poor clinical outcome which compels the development of novel and effective therapeutic protocols for better clinical outcome. Interestingly, the role of miRNAs in maintaining and regulating the functioning of CSCs through targeting various oncogenic signaling pathways, such as Notch, wingless (WNT)/β-Catenin, janus kinases/ signal transducer and activator of transcription (JAK/STAT), phosphatidylinositol 3-kinase/ protein kinase B (PI3/AKT), and nuclear factor kappa-light-chain-enhancer of activated B (NF-kB), is critical and poses a huge challenge to cancer treatment. Based on recent findings, here, we have documented the regulatory action or the underlying mechanisms of how miRNAs affect the signaling pathways attributed to stemness features of CSCs, such as self-renewal, differentiation, epithelial to mesenchymal transition (EMT), metastasis, resistance and recurrence etc., associated with the pathogenesis of various types of human malignancies including colorectal cancer, lung cancer, breast cancer, head and neck cancer, prostate cancer, liver cancer, etc. We also shed light on the fact that the targeted attenuation of deregulated functioning of miRNA related to stemness in human carcinogenesis could be a viable approach for cancer treatment.

CUL4B regulates cancer stem-like traits of prostate cancer cells by targeting BMI1 via miR200b/c

BACKGROUND

Cancer stem-like traits contribute to prostate cancer (PCa) progression and metastasis. Cullin 4B (CUL4B) is a member of the ubiquitin E3 ligase family and overexpressed in several solid malignancies including PCa. CUL4B has been suggested to be an oncogene through epigenetic repression of tumor suppressors. However, the link between CUL4B expression and cancer stem-like phenotype remains unclear.

METHODS

Western blot analysis, sphere formation, and colony formation assays were used to examine the effect of CUL4B on cancer stem-like traits in PCa cells. Mechanically, bioinformatic analysis was utilized to evaluate whether BMI1 was a target of CUL4B. Moreover, real-time polymerase chain reaction, chromatin immunoprecipitation, and luciferase reporter assays were performed to identify microRNAs regulated by CUL4B. Finally, Western blot assay was used to validate the regulation of CUL4B, miR200b, and miR200c (miR200b/c) on the stem-like characteristics of PCa cells.

RESULTS

CUL4B promotes PCa pluripotency-associated markers expression, sphere formation, and anchorage-independent growth ability in vitro. Mechanically, CUL4B upregulates BMI1 expression via epigenetically repressing miR200b/c expression. In addition, miR200b/c could partially reverse CUL4B-induced BMI1 and pluripotency-associated marker expression.

CONCLUSIONS

Our study revealed that CUL4B regulates cancer stem-like traits of prostate cancer cells by targeting BMI1 via miR200b/c, which might give novel insight into how CUL4B promotes PCa progression through regulating cancer stem-like traits.

The subpopulation of CD44-positive cells promoted tumorigenicity and metastatic ability in lung adenocarcinoma

BACKGROUND

Lung cancer is one of the major causes of carcinoma-related deaths in the world. Importantly, lung adenocarcinoma (LAC) is the most common type with poor outcome. However, the progressive clinical phenotype and biomolecular signature of lung cancer presenting the cancer stem-like and metastatic characteristics are still unclear.

METHODS

In this study, we identified CD44 marker in lung cancers. The capabilities, including tumorigenic and migration assays, were analyzed in CD44 expression and CD44 expression subgroups. Meanwhile, the potential bio-signature and properties of lung tumor stem-like cells were further studied.

RESULTS

The high expression of CD44 subpopulation (CD44-positive) in isolated lung cancer cells showed significantly higher abilities of tumorigenic colonies, tumor-sphere formation, and migratory properties when compared with the CD44 expression group. These subgroups of CD44-positive lung cancer cells further demonstrated the metastatic potential with epithelial-mesenchymal transition (EMT), as well as the high expression of Twist and Snail gene profile. Importantly, the overexpression of Snail with gene vector in CD44 expression cells further significantly promoted the properties of lung tumor stem-like cells.

CONCLUSION

The results of this study highlighted the role of CD44-posivite subpopulation in modulating tumor initiation and EMT-based metastatic ability of lung malignancy.

Exploiting epigenetically mediated changes: Acute myeloid leukemia, leukemia stem cells and the bone marrow microenvironment

Acute myeloid leukemia (AML) derives from the clonal expansion of immature myeloid cells in the bone marrow, and results in the disruption of normal hematopoiesis and subsequent bone marrow failure. The bone marrow microenvironment (BME) and its immune and other supporting cells are regarded to facilitate the survival, differentiation and proliferation of leukemia stem cells (LSCs), which enables AML cells to persist and expand despite treatment. Recent studies have identified epigenetic modifications among AML cells and BME constituents in AML, and have shown that epigenetic therapy can potentially reprogram these alterations. In this review, we summarize the interactions between the BME and LSCs, and discuss changes in how the BME and immune cells interact with AML cells. After describing the epigenetic modifications seen across chromatin, DNA, the BME, and the immune microenvironment, we explore how demethylating agents may reprogram these pathological interactions, and potentially re-sensitize AML cells to treatment.

Bioluminescence Imaging for Monitoring miR-200c Expression in Breast Cancer Cells and its Effects on Epithelial-Mesenchymal Transition Progress in Living Animals

PURPOSE

Dysregulation of microRNAs (miRNAs) are not only involved in the formation of malignant tumors but also in the processes of differentiation and aggressiveness. However, current methods for detecting miRNA expression have major disadvantages, such as being invasive and non-reproducible. The epithelial-mesenchymal transition (EMT) has been implicated as a pivotal event in the metastasis, stemness, and chemoresistance of malignant tumors.

PROCEDURES

In our study, we constructed a new reporter gene, Luc2/tdT_miR200c_3TS, to examine the in vitro and in vivo expression of miR-200c, an EMT-associated miRNA. Quantitative real-time PCR was used to measure the expression levels of miR-200c and EMT-related mRNA, and luciferase assay and bioluminescence imaging were used to measure the luciferase activities in vitro and in vivo, respectively.

RESULTS

We found that the expression level of miR-200c was negatively associated with cell migration and invasion. Luciferase activities were regulated by the differential expression levels of miR-200c and EMT process.

CONCLUSIONS

Our results demonstrate that Luc2/tdT_miR200c_3TS may be a useful tool for monitoring the expression level of miR-200c at both the cellular level and in living animals, thereby providing a potential high-throughput approach for anticancer drug screening.

miR-1246 Targets CCNG2 to Enhance Cancer Stemness and Chemoresistance in Oral Carcinomas

MiRNAs have been recognized as crucial components in carcinogenesis, but whether miR-1246 affects the cancer stemness and drug resistance in oral squamous cell carcinoma (OSCC) has not been fully understood and its downstream targets still need to be unraveled. In the present work, we employed miRNAs RT-PCR analysis to evaluate the expression of miR-1246 in tumor tissues and oral cancer stem cells (OCSC). Stemness phenotypes, including self-renewal, migration, invasion, colony formation capacities, and in vivo oncogenicity of oral cancer cells following transfected with miR-1246 inhibitors or mimics were examined. Our results suggested that the expression level of miR-1246 was significantly upregulated in the tumor tissues and OCSC. Kaplan-Meier survival analysis of OSCC patients with high levels of miR-1246 had the worst survival rate compared to their low-expression counterparts. Inhibition of miR-1246 in OCSC significantly reduced the stemness hallmarks, while overexpression of miR-1246 enhanced these characteristics. Moreover, we showed that downregulation of miR-1246 decreased chemoresistance. In addition, we verified that miR-1246-inhibited CCNG2 contributed to the cancer stemness of OSCC. These results demonstrated the significance of miR-1246 in the regulation of OSCC stemness. Targeting miR-1246-CCNG2 axis may be beneficial to suppress cancer relapse and metastasis in OSCC patients.

2D and 3D cell cultures - a comparison of different types of cancer cell cultures

Cell culture is a widely used in vitro tool for improving our understanding of cell biology, tissue morphology, and mechanisms of diseases, drug action, protein production and the development of tissue engineering. Most research regarding cancer biology is based on experiments using two-dimensional (2D) cell cultures in vitro. However, 2D cultures have many limitations, such as the disturbance of interactions between the cellular and extracellular environments, changes in cell morphology, polarity, and method of division. These disadvantages led to the creation of models which are more closely able to mimic conditions in vivo. One such method is three-dimensional culture (3D). Optimisation of the culture conditions may allow for a better understanding of cancer biology and facilitate the study of biomarkers and targeting therapies. In this review, we compare 2D and 3D cultures in vitro as well as different versions of 3D cultures.

Andrographolide impedes cancer stemness and enhances radio-sensitivity in oral carcinomas via miR-218 activation

Current evidence suggests that oral cancer stem cells (OCSCs) possess high tumorigenic and metastatic properties as well as chemo- and radioresistance. In this study, we demonstrated that andrographolide, the main bioactive component in the medicinal plant Andrographis, significantly reduced oncogenicity and restored radio-sensitivity of ALDH1⁺CD44⁺ OCSCs. Mechanistic studies showed that andrographolide treatment increased the expression of microRNA-218 (miR-218), leading to the downregulation of Bmi1. We showed that knockdown of miR-218 in ALDH1⁻CD44⁻ non-OCSCs enhanced cancer stemness, while silencing of Bmi1 significantly counteracted it. Furthermore, we found tumor growth was reduced in mice bearing xenograft tumors after andrographolide treatment via activation of miR-218/Bmi1 axis. Together, these data demonstrated that the inhibition of tumor aggressiveness in OCSCs by andrographolide was mediated through the upregulation of miR-218, thereby reducing Bmi1 expression. These findings suggest that andrographolide may be a valuable natural compound for anti-CSCs treatment of OSCC.

Suppression of miR-204 enables oral squamous cell carcinomas to promote cancer stemness, EMT traits, and lymph node metastasis

The feature of oral squamous cell carcinomas (OSCC) is commonly metastasizing to locoreginal lymph nodes, and the involvement of lymph nodes metastasis represents the one of important prognostic factors of poor clinical outcome. MicroRNAs (miRNAs) have been shown to be key players of cancer-related hallmarks including cancer stemness, EMT (epithelial-mesenchymal transition), and metastaisis. Herein we showed that OSCC-derived ALDH1⁺ cancer stem cells (OSCC-CSCs) express lower level of miR-204, and miR-204 over-expression suppresses cancer stemness and in vivo tumor-growth of OSCC-CSCs. miR-204 binds on their 3′UTR-regions of Slug and Sox4 and suppressing their expression in OSCC-CSCs. On the contrary, down-regulation of miR-204 significantly increased cancer stemness and the lymph nodes incidence of orthotopic animal models. Furthermore, co-knockdown with sh-Slug and sh-Sox4 synergistically rescued miR-204-supressing cancer stemness and EMT properties. Clinical results further revealed that a miR-204^lowSlug^highSox4^high signature predicted the worse survival prognosis of OSCC patients by Kaplan-Meier survival analyses. Up-regulated miR-204-targeting Slug and Sox4 by epigallocatechin-3-gallate (EGCG) treatment significantly inhibited the proliferation rate, self-renewal capacity, and the percentage of ALDH1⁺ and CD44⁺ cells in OSCC-CSCs Oral-feeding of EGCG effectively alleviated tumor-progression in OSCC-CSCs-xenotransplanted immunocompromised mice through miR-204 activation. In conclusion, miR-204-mediated suppression of cancer stemness and EMT properties could be partially augmented by the anti-CSCs effect of EGCG.

miR-200c-3p spreads invasive capacity in human oral squamous cell carcinoma microenvironment

Oral squamous cell carcinoma (OSCC) constitutes over 90% of all cancers in the oral cavity. The prognosis for patients with invasive OSCC is poor; therefore, it is important to understand the molecular mechanisms of invasion and subsequent metastasis not only to prevent cancer progression but also to detect new therapeutic targets against OSCC. Recently, extracellular vesicles-particularly exosomes-have been recognized as intercellular communicators in the tumor microenvironment. As exosomic cargo, deregulated microRNAs (miRNAs) can shape the surrounding microenvironment in a cancer-dependent manner. Previous studies have shown inconsistent results regarding miR-200c-3p expression levels in OSCC cell lines, tissues, or serum-likely because of the heterogeneous characters of the specimen materials. For this reason, single-cell clone analyses are necessary to effectively assess the role of exosome-derived miRNAs on cells within the tumor microenvironment. The present study utilized integrated microarray profiling to compare exosome-derived miRNA and exosome-treated cell-derived mRNA expression. Data were acquired from noninvasive SQUU-A and highly invasive SQUU-B tongue cancer cell clones derived from a single patient to determine candidate miRNAs that promote OSCC invasion. Matrigel invasion assays confirmed that hsa-miR-200c-3p was a key pro-invasion factor among six miRNA candidates. Consistently, silencing of the miR-200c-3p targets, CHD9 and WRN, significantly accelerated the invasive potential of SQUU-A cells. Thus, our data indicate that miR-200c-3p in exosomes derived from a highly invasive OSCC line can induce a similar phenotype in non-invasive counterparts.

miR-200b-3p in plasma is a potential diagnostic biomarker in oral squamous cell carcinoma

CONTEXT

Circulating MicroRNAs (miRNAs) are emerging as novel biomarkers for tumour.

OBJECTIVE

Evaluate the diagnostic potential of plasma miR-200b-3p in oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

miR-200b-3p was detected by qRT-PCR in paired pre-operative and post-operative plasmas from 80 OSCC patients and 80 healthy controls.

RESULTS

Plasma miR-200b-3p was significantly upregulated in OSCC, and it was higher in WHO II/III grade than WHO I grade. The AUC of miR-200b-3p for OSCC was 0.9173. miR-200b-3p was significantly downregulated after surgery. High miR-200b-3p expression was associated with poor prognosis.

DISCUSSION AND CONCLUSION

Plasma miR-200b-3p could be a potential diagnostic biomarker for OSCC.

MicroRNA-200c binding to FN1 suppresses the proliferation, migration and invasion of gastric cancer cells

We aimed to investigate the effects of miR-200c binding to fibronectin 1 (FN1) on proliferation, migration and invasion of gastric cancer (GC) cells. A total of 52 GC tissues and their corresponding normal adjacent tissue samples were collected. Then, miR-200c and FN1 were tested using quantitative real-time RT-PCR in the clinical specimens and GC cells, while immunohistochemistry and western blotting assay were carried out to detect FN1 expressions. Dual luciferase reporter gene assay was used to assess the effect of miR-200c on the luciferase activity of FN1 3'UTR. BGC-823 cells were transfected with miR-200c mimics, miR-200c inhibitors and FN1 siRNA, respectively. The effects of miR-200c inhibitors and FN1 siRNA on cellular proliferation, migration and invasion were detected through MTT assay and Transwell assay. Compared to normal tissues and cells, miR-200c was significantly down-regulated and FN1 was significantly up-regulated (P<0.01). Dual luciferase reporter gene assay showed that miR-200c could specifically bind to the 3'-UTR of FN1 and significantly repress the luciferase activity (P<0.01). Both mRNA and protein expressions of FN1 were decreased significantly in GC cells when miR-200c was over expressed. The proliferation, migration and invasion of GC cells could be suppressed by over-expression of miR-200c or down-regulation of FN1. In conclusion, miR-200c was significantly down-regulated in both GC tissues and cell lines, while FN1 presented the opposite trends. Besides, miR-200c inhibited the proliferation, migration and invasion of GC cells through binding to FN1.

Downregulation of miR-1 enhances tumorigenicity and invasiveness in oral squamous cell carcinomas

BACKGROUND/PURPOSE

Cumulative evidence suggest that microRNAs (miRNAs) function as biosignatures of oral squamous cell carcinomas (OSCC). However, the functional roles of miR-1 as well as its downstream targets in the regulation of tumorigenicity in OSCC remain unclear.

METHODS

miRNAs RT-PCR analysis was performed to identify miR-1 as a putative candidate on mediating invasiveness of OSCC cells. Consequently, we elucidated the tumorigenicity of OSCC cells with miR-1 downregulation or overexpression, respectively. Finally, miR-1 on OSCC tumor tissues was examined.

RESULTS

miR-1 levels were significantly downregulated in the malignant OSCC cells. Overexpression of miR-1 significantly reduced migration/invasiveness of OSCC cells. In addition, overexpression of miR-1 decreased cancer stem cells properties. Conversely, downregulation of miR-1 promotes migration and invasiveness in OSCC cells. We have shown that miR-1 is able to target Slug, suppressing their expression. Clinically, lower miR-1 expression was found in patients with advanced nodal metastasis OSCC.

CONCLUSION

miR-1 as novel biosignatures in OSCC lymph node metastatic patients, supporting the development of novel strategies for OSCC treatment.

Activation of microRNA-494-targeting Bmi1 and ADAM10 by silibinin ablates cancer stemness and predicts favourable prognostic value in head and neck squamous cell carcinomas

Tumor initiating cells (TICs) possessing cancer stemness were shown to be enriched after therapy, resulting in the relapse and metastasis of head and neck squamous cell carcinomas (HNC). An effective therapeutic approach suppressing the HNC-TICs would be a potential method to improve the treatments for HNC. We observed that the treatment of silibinin (SB) dose dependently down-regulated the ALDH1 activity, CD133 positivity, stemness signatures expression, self-renewal property, and chemoresistance in ALDH1+CD44+ HNC-TICs. Using miRNA-microarray and mechanistic studies, SB increased the expression of microRNA-494 (miR-494) and both Bmi1 and ADAM10 were identified as the novel targets of miR-494. Moreover, overexpression of miR-494 results in a reduction in cancer stemness. However, knockdown of miR-494 in CD44⁻ALDH1⁻non-HNC-TICs enhanced cancer stemness and oncogenicity, while co-knockdown of Bmi1 and ADAM10 effectively reversed these phenomena. Mice model showed that SB treatment by oral gavage to xenograft tumors reduced tumor growth and prolonged the survival time of tumor-bearing mice by activation of miR-494-inhibiting Bmi1/ADAM10 expression. Survival analysis indicated that a miR494^highBmi1^lowADAM10^low phenotype predicted a favourable clinical outcome. We conclude that the inhibition of tumor aggressiveness in HNC-TICs by SB was mediated by up-regulation miR-494, suggesting that SB would be a valuable anti-cancer drug for treatment of HNC.

BMI1: A Biomarker of Hematologic Malignancies

BMI1 oncogene is a catalytic member of epigenetic repressor polycomb group proteins. It plays a critical role in the regulation of gene expression pattern and consequently several cellular processes during development, including cell cycle progression, senescence, aging, apoptosis, angiogenesis, and importantly self-renewal of adult stem cells of several lineages. Preponderance of evidences indicates that deregulated expression of PcG protein BMI1 is associated with several human malignancies, cancer stem cell maintenance, and propagation. Importantly, overexpression of BMI1 correlates with therapy failure in cancer patients and tumor relapse. This review discusses the diverse mode of BMI1 regulation at transcriptional, posttranscriptional, and posttranslational levels as well as at various critical signaling pathways regulated by BMI1 activity. Furthermore, this review highlights the role of BMI1 as a biomarker and therapeutic target for several subtypes of hematologic malignancies and the importance to target this biomarker for therapeutic applications.

Concise review: custodians of the transcriptome: how microRNAs guard stemness in squamous epithelia

At the core of every dynamic epithelium resides a population of carefully regulated stem cells ensuring its maintenance and balance. The complex mammalian epidermis is no exception to this rule. The last decade has delivered a wealth of knowledge regarding the biology of adult stem cells, but questions still remain regarding the intricate details of their function and maintenance. To help address these gaps, we turn to the small, single-stranded RNA molecules known as microRNAs. Since their discovery, microRNAs have provided us with novel insights and ground-breaking impulses to enhance our understanding of the biological sciences. Due to their unique role in post-transcriptional regulation, microRNAs are essential to cutaneous biology as well as the epidermal stem cell. By serving as buffers to balance between epithelial stemness, proliferation, and differentiation, microRNAs play essential roles in the maintenance of cutaneous stem cells and their transition out of the stem cell compartment. Following an updated overview of microRNA biology, we summarize the current knowledge of the role of microRNAs in cutaneous stem cells, focusing on three major players that have dominated the recent literature: miR-205, miR-203, and miR-125b. We then review clinical applications, discussing the potential of microRNAs as therapeutic targets in regenerative and oncological stem cell-based medicine.

MiR-221 promotes stemness of breast cancer cells by targeting DNMT3b

Cancer stem cells (CSCs) are a small part of the heterogeneous tumor cell population possessing self-renewal and multilineage differentiation potential as well as a great ability to sustain tumorigenesis. The molecular pathways underlying CSC phenotype are not yet well characterized. MicroRNAs (miRs) are small noncoding RNAs that play a powerful role in biological processes. Early studies have linked miRs to the control of self-renewal and differentiation in normal and cancer stem cells. We aimed to study the functional role of miRs in human breast cancer stem cells (BCSCs), also named mammospheres. We found that miR-221 was upregulated in BCSCs compared to their differentiated counterpart. Similarly, mammospheres from T47D cells had an increased level of miR-221 compared to differentiated cells. Transfection of miR-221 in T47D cells increased the number of mammospheres and the expression of stem cell markers. Among miR-221's targets, we identified DNMT3b. Furthermore, in BCSCs we found that DNMT3b repressed the expression of various stemness genes, such as Nanog and Oct 3/4, acting on the methylation of their promoters, partially reverting the effect of miR-221 on stemness. We hypothesize that miR-221 contributes to breast cancer tumorigenicity by regulating stemness, at least in part through the control of DNMT3b expression.

The increase of oncogenic miRNA expression in tongue carcinogenesis of a mouse model

OBJECTIVES

This study investigated the oncogenic miRNA level in the tissue and biofluids in the Nitroquinoline 1-Oxide (4NQO)-induced mouse tongue carcinogenesis model for potential diagnostic or therapeutic application.

MATERIALS AND METHODS

The histological examination, immunohistochemistry, in situ hybridization, quantitative PCR analysis and bioinformatic algorithms were performed to unravel the signaling activation and miRNA expression in female murine samples.

RESULTS

The increase of miR-21 and miR-31 staining, and EGFR activation paralleled the severity of 4NQO-induced epithelial pathogenesis in tongue epithelium. A progressive increase of miR-21, miR-31 and miR-146a in both saliva and plasma samples was also noted. miR-31 was the earliest emerging miRNA in the saliva. The increase of plasma miR-146a, miR-184 and miR-372 was detectable early in the induction, and it was particularly eminent at the most advanced lesion state. The combined analysis of the multiple oncogenic miRNAs in the plasma signified a potent discriminative capacity between normal and pathological states. As the blockage of EGFR or AKT activation drastically reverted the miR-21, miR-31 and miR-146a expression induced by 4NQO in human oral carcinoma cell lines, the results implicated a mechanistic linkage of the oncogenic miRNAs' induction through EGFR/AKT activation.

CONCLUSIONS

In this study, we show the dysregulation of oncogenic miRNAs in murine tongue tumorigenesis, which simulates human counterparts. Increased multiple miRNAs in the biofluids may be valuable non-invasive markers in detecting oral carcinogenesis at an early stage. This animal model may also be useful for developing liquid biopsies and prevention strategies against oral carcinoma by abrogating EGFR or oncogenic miRNAs.

Co-targeting of multiple microRNAs on factor-Inhibiting hypoxia-Inducible factor gene for the pathogenesis of head and neck carcinomas

BACKGROUND

MicroRNAs (miRNAs) are short, noncoding RNAs that inhibit the expression of target genes that play roles in tumorigenesis. MiR-21, miR-31, and miR-184 are oncogenic miRNAs for head and neck squamous cell carcinoma (HNSCC). Factor-inhibiting hypoxia (FIH)-inducible factor is known to inactivate hypoxia-induced downstream effectors and is involved in HNSCC suppression. This study investigates whether miR-21, miR-31, and miR-184 target FIH in HNSCC.

METHODS

Reporter assays, Western blot analysis, quantitative reverse transcriptase-polymerase chain reaction (PCR) analysis, and phenotypic assays were used to prove that miR-21, miR-31, and miR-184 directly target FIH. Clinicopathological implications of the gene expression were also analyzed.

RESULTS

MiR-21, miR-31, and miR-184 directly bind to various sites in the 3' untranslated region (UTR) of FIH transcript, and this binding is associated with decreased FIH protein expression in HNSCC cells. Treatment with the precursors of these miRNAs increases the proliferation and migration of HNSCC cells. Concomitant treatment with precursors repressed FIH and enhanced oncogenicity most profoundly. Upregulation of miR-21, miR-31, and miR-184 expression is found in more than 80% of HNSCC tumors and 72% of tumors have concordant upregulation of these 3 oncogenic miRNAs. The highest expression of these miRNAs is present in T4b and stage IVB tumors. Downregulation of FIH mRNA expression is noted in 69% of HNSCC tumors, and in tumors exhibiting high expression of these miRNAs, the FIH mRNA expression is consistently downregulated.

CONCLUSION

This study provides novel clues indicating that miR-21, miR-31, and miR-184 co-target FIH tumor suppressor during pathogenesis in the vast majority of HNSCC.

Targeting CD133 in the enhancement of chemosensitivity in oral squamous cell carcinoma-derived side population cancer stem cells

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the most common cancers in the world. Previously, we enriched a subpopulation of OSCC-derived cancer stem cells (OSCC-CSCs), and identified CD133 as an OSCC-CSC marker.

METHOD

We determined the function of CD133 on chemosensitivity of oral cancer CSCs by silencing CD133.

RESULTS

Initially, we observed that the expression profile of CD133 in OSCC-side population (OSCC-SPs) cells, which exerted properties of CSCs, was significantly upregulated than that of major population (MPs) cells of OSCCs. The cell viability experiments showed that SPs were more chemoresistant compared with major populations. Importantly, targeting CD133 ameliorated the drug resistance of OSCC-SPs to cisplatin treatment. Targeting CD133 and cisplatin co-treatment led to the maximal inhibition on tumor initiating properties in OSCC-SPs.

CONCLUSION

Side population cells with CSCs properties existed in OSCCs, and silencing CD133 exhibited a prominent therapeutic effect in enhancing the sensitivity of chemotherapy in OSCC through elimination of CSCs. © 2015 Wiley Periodicals, Inc. Head Neck 38: E231-E238, 2016.