miR-203 inhibits cell proliferation and promotes cisplatin induced cell death in tongue squamous cancer

MicroRNA-203a inhibits breast cancer progression through the PI3K/Akt and Wnt pathways

MicroRNA expression in breast cancer (BC) is explored both as a potential biomarker and for therapeutic purposes. Recent studies have revealed that miR-203a-3p is involved in BC, and importantly contributes to BC chemotherapy responses; however, the regulatory pathways of miR-203a in BC remain elusive. Hence, we aimed to investigate the miR-203a regulatory mechanisms and their potential functions in the progress of BC. To this end, the miR-203a potential involving pathways was predicted by databases analyzing its target genes. The relations between miR-203a, the phosphatidylinositol 3'-kinase (PI3K)-Akt, and Wnt signaling pathways were mechanistically investigated. Our results revealed that miR-203a inhibited the activation of the PI3K/Akt and Wnt pathways and reduced its downstream cell cycle signals, including Cyclin D1 and c-Myc. Moreover, the overexpression of miR-203a drastically arrested the cell cycle at subG1 and G1 phases, decreased the viability, proliferation, and migration, and increased apoptosis of BC cells. Therefore, miR-203a-3p may be considered a tumor suppressor factor and a potential biomarker or therapeutic target for BC.

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.

MicroRNAs as the pivotal regulators of cisplatin resistance in head and neck cancers

Although, there is a high rate of good prognosis in early stage head and neck tumors, about half of these tumors are detected in advanced stages with poor prognosis. A combination of chemotherapy, radiotherapy, and surgery is the treatment option in head and neck cancer (HNC) patients. Although, cisplatin (CDDP) as the first-line drug has a significant role in the treatment of HNC patients, CDDP resistance can be observed in a large number of these patients. Therefore, identification of the molecular mechanisms involved in CDDP resistance can help to reduce the side effects and also provides a better therapeutic management. MicroRNAs (miRNAs) as the post-transcriptional regulators play an important role in drug resistance. Therefore, in the present review we investigated the role of miRNAs in CDDP response of head and neck tumors. It has been reported that the miRNAs exerted their roles in CDDP response by regulation of signaling pathways such as WNT, NOTCH, PI3K/AKT, TGF-β, and NF-kB as well as apoptosis, autophagy, and EMT process. The present review paves the way to suggest a non-invasive miRNA based panel marker for the prediction of CDDP response among HNC patients. Therefore, such diagnostic miRNA based panel marker reduces the CDDP side effects and improves the clinical outcomes of these patients following an efficient therapeutic management.

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.

Long non-coding RNA in glioma: novel genetic players in temozolomide resistance

Glioma is the most common primary malignant brain tumor in adults and accounts for approximately 80% of brain and central nervous system tumors. In 2021, the World Health Organization (WHO) published a new taxonomy for glioma based on its histological features and molecular alterations. Isocitrate dehydrogenase (IDH) catalyzes the decarboxylation of isocitrate, a critical metabolic reaction in energy generation in cells. Mutations in the IDH genes interrupt cell differentiation and serve as molecular biomarkers that can be used to classify gliomas. For example, the mutant IDH is widely detected in low-grade gliomas, whereas the wild type is in high-grade ones, including glioblastomas. Long non-coding RNAs (lncRNAs) are epigenetically involved in gene expression and contribute to glioma development. To investigate the potential use of lncRNAs as biomarkers, we examined lncRNA dysregulation dependent on the IDH mutation status. We found that several lncRNAs, namely, AL606760.2, H19, MALAT1, PVT1 and SBF2-AS1 may function as glioma risk factors, whereas AC068643.1, AC079228.1, DGCR5, FAM13A-AS1, HAR1A and WDFY3-AS2 may have protective effects. Notably, H19, MALAT1, PVT1, and SBF2-AS1 have been associated with temozolomide resistance in glioma patients. This review study suggests that targeting glioma-associated lncRNAs might aid the treatment of glioma.

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.

miR-214 Modulates the Growth and Migration of Oral Cancer before and after Chemotherapy through Mediating ULK1

The role of miRNAs as crucial components in carcinogenesis has been well documented. However, whether and how miR-214 influences oral cancer cells' drug resistance remains to be elucidated, and its downstream targets are still under investigation. Hence, this research is aimed at determining miR-214 and ULK1 expression in oral cancer before and after chemotherapy and their correlations with cancer cell growth. Human oral normal epithelial cells and human tongue squamous cell carcinoma CAL-27 cells were cultured to detect miR-214 and ULK1 levels. It was found that before chemotherapy, miR-214 was higher, while ULK1 was underexpressed in CAL-27 cells, versus normal epithelial cells. After chemotherapy, miR-214 decreased obviously in CAL-27 cells, while ULK1 level increased significantly. In addition, autophagy-related genes (Beclin 1, mTOR, and P53) in CAL-27 cells were found to be significantly inhibited before chemotherapy and were obviously increased after chemotherapy. Moreover, to further determine the impacts of miR-214 and ULK1 on oral cancer cell growth after chemotherapy, the two were overexpressed or silenced in CAL-27 cells after transfection. We found that ULK1 could effectively decrease the activity and invasion of CAL-27 cells and increase their apoptosis level, while miR-214 could antagonize its antitumor effect. Therefore, miR-214 can be used as an early prognostic biomarker for oral cancer, and ULK1 is a new candidate therapeutic target.

Cisplatin resistance-related multi-omics differences and the establishment of machine learning models

Objectives

Platinum-based chemotherapies are currently the first-line treatment of non-small cell lung cancer. This study will improve our understanding of the causes of resistance to cisplatin, especially in lung adenocarcinoma (LUAD) and provide a reference for therapeutic decisions in clinical practice.

Methods

Cancer Cell Line Encyclopedia (CCLE), The Cancer Genome Atlas (TCGA) and Zhongshan hospital affiliated to Fudan University (zs-cohort) were used to identify the multi-omics differences related to platinum chemotherapy. Cisplatin-resistant mRNA and miRNA models were constructed by Logistic regression, classification and regression tree and C4.5 decision tree classification algorithm with previous feature selection performed via least absolute shrinkage and selection operator (LASSO). qRT-PCR and western-blotting of A549 and H358 cells, as well as single-cell Seq data of tumor samples were applied to verify the tendency of certain genes.

Results

661 cell lines were divided into three groups according to the IC50 value of cisplatin, and the top 1/3 (220) with a small IC50 value were defined as the sensitive group while the last 1/3 (220) were enrolled in the insensitive group. TP53 was the most common mutation in the insensitive group, in contrast to TTN in the sensitive group. 1348 mRNA, 80 miRNA, and 15 metabolites were differentially expressed between 2 groups (P < 0.05). According to the LASSO penalized logistic modeling, 6 of the 1348 mRNAs, FOXA2, BATF3, SIX1, HOXA1, ZBTB38, IRF5, were selected as the associated features with cisplatin resistance and for the contribution of predictive mRNA model (all of adjusted P-values < 0.001). Three of 6 (BATF3, IRF5, ZBTB38) genes were finally verified in cell level and patients in zs-cohort.

Conclusions

Somatic mutations, mRNA expressions, miRNA expressions, metabolites and methylation were related to the resistance of cisplatin. The models we created could help in the prediction of the reaction and prognosis of patients given platinum-based chemotherapies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03372-0.

LncRNA HOXD‐AS1 promotes oral squamous cell carcinoma by sponging miR‐203a‐5p

OBJECTIVE

In the present study, we aimed to explore lncRNA HOXD cluster antisense RNA 1 (HOXD-AS1) expression in oral squamous cell carcinoma (OSCC) tissues, its biological roles, and the underlying potential mechanisms in OSCC progression.

MATERIALS AND METHODS

HOXD-AS1 expression in paired OSCC and non-tumor tissues from 60 OSCC patients was determined by RT-qPCR. The effects of HOXD-AS1 and miR-203a-5p overexpression on expression of Annexin A4, a validated target of miR-203a-5p, were analyzed by RT-qPCR and Western blot. The roles of HOXD-AS1, miR-203a-5p, and Annexin A4 in the invasion and migration of OSCC cells were analyzed by Transwell assays.

RESULTS

HOXD-AS1 overexpression in OSCC predicted poor survival. HOXD-AS1 was predicted to interact with miR-203a-5p, but its expression was not significantly correlated with miR-203a-5p. HOXD-AS1 overexpression increased Annexin A4 expression, while miR-203a-5p overexpression decreased Annexin A4 expression in OSCC cells. Transwell assays showed that invasion and migration of OSCC cells were enhanced by HOXD-AS1 and Annexin A4 overexpression but were reduced by miR-203a-5p overexpression. In addition, miR-203a-5p overexpression suppressed the role of HOXD-AS1 in cell movement and Annexin A4 expression.

CONCLUSIONS

HOXD-AS1 may upregulate Annexin A4 by sponging miR-203a-5p in OSCC to promote cancer cell invasion and migration.

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.

The Molecular Basis and Therapeutic Aspects of Cisplatin Resistance in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a kind of malignant tumors with low survival rate and prone to have early metastasis and recurrence. Cisplatin is an alkylating agent which induces DNA damage through the formation of cisplatin-DNA adducts, leading to cell cycle arrest and apoptosis. In the management of advanced OSCC, cisplatin-based chemotherapy or chemoradiotherapy has been considered as the first-line treatment. Unfortunately, only a portion of OSCC patients can benefit from cisplatin treatment, both inherent resistance and acquired resistance greatly limit the efficacy of cisplatin and even cause treatment failure. Herein, this review outline the underlying mechanisms of cisplatin resistance in OSCC from the aspects of DNA damage and repair, epigenetic regulation, transport processes, programmed cell death and tumor microenvironment. In addition, this review summarizes the strategies applicable to overcome cisplatin resistance, which can provide new ideas to improve the clinical therapeutic outcome of OSCC.

MicroRNA-203 inhibits epithelial-mesenchymal transition, migration, and invasion of renal cell carcinoma cells via the inactivation of the PI3K/AKT signaling pathway by inhibiting CAV1

The present study aimed to evaluate the underlying mechanism of microRNA-203 (miR-203) in renal cell carcinoma (RCC) involving the PI3K/AKT signaling pathway. The results revealed downregulated miR-203 and upregulated CAV1 in RCC tissues. Upregulated miR-203 and downregulated CAV1 increased E-cadherin expression and cell apoptosis, decreased β-catenin and N-cadherin expression and cell proliferation, migration and invasion, and blocked cell cycle entry. CAV1, a target gene of miR-203, decreased by up-regulated miR-203, and silencing CAV1 led to the inactivation of PI3K/AKT signaling pathway. In conclusion, our findings suggested that miR-203-mediated direct suppression of CAV1 inhibits EMT of RCC cells via inactivation of the PI3K/AKT signaling pathway.

Knockdown of microRNA-203 reduces cisplatin chemo-sensitivity to osteosarcoma cell lines MG63 and U2OS in vitro by targeting RUNX2

Clinical studies have reported that miRNAs abnormal expression are associated with the generation of cisplatin-resistant to osteosarcoma. Our previous research found that miR-203 is downregulated in osteosarcoma cells and overexpressed miR-203 exerts antitumor properties on osteosarcoma cells. However, the role and mechanism of miR-203 in regulating the sensitivity of cisplatin in osteosarcoma cells remains unclear. This study aimed to investigate the effects of miR-203 in cisplatin therapy for osteosarcoma cells in vitro and determined the underlying mechanism. In this study, we found that miR-203 was significantly upregulated in osteosarcoma cells after exposure to cisplatin. miR-203 knockdown reduced the sensitivity of osteosarcoma cells to cisplatin by suppressing cell apoptosis, cell cycle arrest, and inducing invasion. Meanwhile, we found that miR-203 knockdown reduces the therapeutic sensitivity of osteosarcoma cells by upregulating RUNX2. Moreover, we found that RUNX2 silencing sensitizes osteosarcoma cells to chemotherapy treatment of cisplatin. In summary, our findings demonstrated that miR-203 knockdown reduces cisplatin chemo-sensitivity to osteosarcoma cells in vitro by targeting RUNX2, and speculated that miR-203 may be a target for drug resistance of osteosarcoma to cisplatin.

microRNAs deregulation in head and neck squamous cell carcinoma

Head and neck (HN) squamous cell carcinoma (SCC) is the eighth most common human cancer worldwide. Besides tobacco and alcohol consumption, genetic and epigenetic alterations play an important role in HNSCC occurrence and progression. microRNAs (miRNAs) are small noncoding RNAs that regulate cell cycle, proliferation, development, differentiation, and apoptosis by interfering in gene expression. Expression profiling of miRNAs showed that some miRNAs are upregulated or downregulated in tumor cells when compared with the normal cells. The present review focuses on the role of miRNAs deregulations in HNSCC, enrolled in risk, development, outcome, and therapy sensitivity. Moreover, the influence of single nucleotide variants in miRNAs target sites, miRNAs seed sites, and miRNAs-processing genes in HNSCC was also revised. Due to its potential for cancer diagnosis, progression, and as a therapeutic target, miRNAs may bring new perspectives in HNSCC understanding and therapy, especially for those patients with no or insufficient treatment options.

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.

Functional Landscape of Dysregulated MicroRNAs in Oral Squamous Cell Carcinoma: Clinical Implications

MicroRNA (miRNA) dysregulation is associated with the pathogenesis of oral squamous cell carcinoma (OSCC), and its elucidation could potentially provide information on patient outcome. A growing body of translational research on miRNA biology is focusing on precision oncology, aiming to decode the miRNA regulatory network in the development and progression of cancer. Tissue-specific expression and stable presence in all body fluids are unique features of miRNAs, which could be potentially exploited in the clinical setting. Recent understanding of miRNA properties has led them to be useful, attractive, and potential tools either as biomarkers (distinct miRNA expression signature) for diagnosis and prognostic outcomes or as targets for novel therapeutic entities, enabling personalized treatment for OSCC. In this review, we discuss recent research on different aspects of alterations in miRNA profiles along with their clinical significance and strive to identify probable potential miRNA biomarkers for diagnosis and prognosis of OSCC. We also discuss the current understanding and scope of development of miRNA-based therapeutics against OSCC.

Overexpression of microRNA-203 Suppresses Proliferation, Invasion, and Migration while Accelerating Apoptosis of CSCC Cell Line SCL-1

Cutaneous squamous cell carcinoma (CSCC) is a malignant proliferation of cutaneous epithelium that has been observed to have an alarming rise in incidence. Numerous studies have demonstrated microRNAs (miRNAs or miRs) as important biomarkers in the diagnosis, prognosis, and treatment of CSCC. This study aims to investigate the effects of miR-203 on the behaviors of CSCC cells and possible mechanisms associated with protein regulator of cytokinesis-1 (PRC1) and Wnt/β-catenin signaling pathway. PRC1 was suggested as a target of miR-203 in squamous cell carcinoma cell line 1 (SCL-1) cells by dual-luciferase reporter gene assay. Based on the immunohistochemical staining and qRT-PCR, PRC1 was abundantly expressed while miR-203 was poorly expressed in CSCC tissues. miR-203 mimic or inhibitor was transfected into SCL-1 cells to upregulate or downregulate its expression. Upregulation of miR-203 downregulated PRC1 expression to block the Wnt/β-catenin signaling pathway. By conducting 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), scratch test, and Transwell and flow cytometric analyses, miR-203 was witnessed to restrain SCL-1 cell proliferation, migration, and invasion while accelerating their apoptosis. The rescue experiments addressed that inhibition of the Wnt/β-catenin signaling pathway conferred the anti-tumor effect of miR-203. These results establish a tumor-suppressive role for miR-203 in CSCC cell line SCL-1. Hence, miR-203 has promising potential as a therapeutic target for CSCC.

MicroRNA-203 restrains epithelial-mesenchymal transition, invasion and migration of papillary thyroid cancer by downregulating AKT3

MicroRNAs (miRNAs) have been reported to serve pivotal roles in the regulation of papillary thyroid cancer (PTC) development; thus, the aim of this study is to identify the impact of miR-203 and AKT3 on the epithelial-mesenchymal transition (EMT), migration and invasion of PTC. MiR-203 and AKT3 expression in PTC tissues and cells were tested. TPC-1 cells and K1 cells were screened for follow-up experiments. Apoptosis-related proteins (Bcl-2 and Bax), EMT-related proteins (Vimentin and E-cadherin), proliferation-associated proteins (Ki67 and CDK4), invasion- and migration-related protein (MMP-2 and MMP-9) were verified. The effects of upregulated miR-203 and downregulated AKT3 on the biological characteristics of PTC cells in each group were detected via the gain- and loss-of-function assays. The targeting relationship between miR-203 and AKT3 was verified.MiR-203 expression declined and AKT3 heightened in PTC tissues and cells. Upregulated miR-203 and downregulated AKT3 reduced the tumor volume and weight, suppressed cell migration, colony formation, proliferation, invasion, proliferation-associated proteins (Ki67 and CDK4), invasion- and migration-related protein (MMP-2 and MMP-9) and promoted cell apoptosis, raised E-cadherin and decreased Vimentin protein expression in TPC-1 cells. On the contrary, the K1 cells with the downregulated miR-203 or upregulated AKT3 exhibited an opposite result. This study suggests that upregulated miR-203 suppresses EMT, invasion, proliferation and migration as well as induces apoptosis of PTC cells via downregulated AKT3.

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.

Meta-analysis of microRNAs expression in head and neck cancer: uncovering association with outcome and mechanisms

Head and neck squamous cell carcinoma (HNSCC) is often diagnosed at advanced stages, incurring significant high mortality and morbidity. This review explored the risk stratification of miRNAs, and investigated the impact of miRNA networking in HNSCC prognostication. We performed a meta-analysis and a systematic literature search on online databases for papers published prior to December 1, 2016. The list of miRNAs was uploaded to MetacoreTM to construct a protein-protein interaction network, which was used to identify targets of the miRNAs and potential drugs. In addition, a representative network was further validated by immunohistochemistry in a cohort of 100 patients. We found 116 studies that included 8,194 subjects, in which the relationship between miRNA expression and prognosis of HNSCC were analyzed. Significant elevated expressions of 27 miRNAs and decreased expression of 26 miRNAs were associated with poor outcome. After excluding the studies causing heterogeneity, a fixed model was applied, which showed a statistically significant association between increased expression of miR-21 and poor survival (Pooled HR = 1.81,95% CI = 0.66-2.95, P < 0.005). We identified four networks affected by the miRNAs expression and enriched in genes related to metabolic processes and regulation of cell mitogenesis in response to extracellular stimuli. One network point out to 16 miRNAs directly or indirectly involved in the regulation of androgen-receptor (AR). Evaluation of AR protein expression in our cohort revealed that patients with upregulation of AR had poor survival rates (log-rank test, P < 0.005). This study showed that miRNAs have potential prognostic value to serve as screening tool for HNSCC during the follow-up. In addition, the implementation of a network-based analysis may reveal proteins with potential to be used as a biomarker.

MALAT1 is a prognostic factor in glioblastoma multiforme and induces chemoresistance to temozolomide through suppressing miR-203 and promoting thymidylate synthase expression

Glioblastoma multiforme (GBM) is the most malignant brain tumor with limited therapeutic options. Temozolomide (TMZ) is a novel cytotoxic agent used as first-line chemotherapy for GBM, however, some individual cells can't be isolated for surgical resection and show treatment-resistance, thus inducing poor prognosis. By using the HiSeq sequencing and bioinformatics methods, we identified lncRNAs showing different expression levels in TMZ-resistant and non-resistant patients. RT-qPCR was then performed in tissues and serum samples, and lncRNA MALAT1 was finally identified to show considerable discriminating potential to identify responding patients from non-responding patients. Moreover, high serum MALAT1 expression was associated with poor chemoresponse and survival in GBM patients receiving TMZ treatment. Subsequently, the TMZ resistant cell lines were established, and the CCK8 assay showed that lncRNA MALAT1 knockdown significantly reversed TMZ resistance in GBM cells. The gain and loss-function experiments revealed that miR-203 was down-regulated by MALAT1 and this interaction has reciprocal effects. Besides, thymidylate synthase (TS) mRNA was identified as a direct target of miR-203. LncRNA MALAT1 inhibition re-sensitized TMZ resistant cells through up-regulating miR-203 and down-regulating TS expression. On the other hand, MALAT1 overexpression promoted resistance by suppressing miR-203 and promoting TS expression. In conclusion, our integrated approach demonstrates that enhanced expression of lncRNA MALAT1 confers a potent poor therapeutic efficacy and inhibition of MALAT1 levels could be a future direction to develop a novel therapeutic strategy to overcome TMZ resistance in GBM patients.