miR-372 inhibits p62 in head and neck squamous cell carcinoma in vitro and in vivo

Interplay of p62-mTORC1 and EGFR signaling promotes cisplatin resistance in oral cancer

Cisplatin resistance poses a major challenge in the treatment of oral squamous cell carcinoma (OSCC). Deeper investigations into the mechanisms underlying this drug resistance is of great importance. Here, we used cellular assays and clinical immunohistochemistry to examine molecular pathways involved in both innate and acquired cisplatin resistance. We demonstrated that the p62-mTORC1 signaling complex plays a pivotal role, and is driven by the EGFR signaling network, specifically through the PI3K-Akt axis and the transcription factor C/EBP-β. Elevated p-mTOR expression was associated with cancer relapse and poor prognosis among oral cancer patients. Additionally, we illustrated that mTOR inhibitors enhance the cytotoxic effect of cisplatin, by employing cancer stem cell characteristics. Our work unveils fundamental mechanisms for cisplatin resistance, thereby presenting therapeutic implications for OSCC.

The sequestosome 1 protein: therapeutic vulnerabilities in ovarian cancer

Ovarian cancer (OC) is the most deadly tumor that may develop in a woman's reproductive system. It is also one of the most common causes of death among those who have been diagnosed with cancer in women. An adapter protein known as sequestosome 1(SQSTM1) or p62 is primarily responsible for the transportation, degradation, and destruction of a wide variety of proteins. This adapter protein works in conjunction with the autophagy process as well as the ubiquitin proteasome degradation pathway. In addition, the ability of SQSTM1 to interact with multiple binding partners link SQSTM1 to various pathways in the context of antioxidant defense system and inflammation. In this review, we outline the processes underlying the control that SQSTM1 has on these pathways and how their dysregulation contributes to the development of OC. At the final, the therapeutic approaches based on SQSTM1 targeting have been discussed.

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.

Feedback Modulation between Human INO80 Chromatin Remodeling Complex and miR-372 in HCT116 Cells

Human INO80 chromatin remodeling complex (INO80 complex) as a transcription cofactor is widely involved in gene transcription regulation and is frequently highly expressed in tumor cells. However, few reports exist on the mutual regulatory mechanism between INO80 complex and non-coding microRNAs. Herein, we showed evidence that the INO80 complex transcriptionally controls microRNA-372 (miR-372) expression through RNA-Seq analysis and a series of biological experiments. Knocking down multiple subunits in the INO80 complex, including the INO80 catalytic subunit, YY1, Ies2, and Arp8, can significantly increase the expression level of miR-372. Interestingly, mimicking miR-372 expression in HCT116 cells, in turn, post-transcriptionally suppressed INO80 and Arp8 expression at both mRNA and protein levels, indicating the existence of a mutual regulatory mechanism between the INO80 complex and miR-372. The target relationship between miR-372 and INO80 complex was verified using luciferase assays in HCT116 colon cancer cells. As expected, miR-372 mimics significantly suppressed the luciferase activity of pMIR-luc/INO80 and pMIR-luc/Arp8 3'-UTR in cells. In contrast, the miR-372 target sites in the 3'-UTRs linked to the luciferase reporter were mutagenized, and both mutant sites lost their response to miR-372. Furthermore, the mutual modulation between the INO80 complex and miR-372 was involved in cell proliferation and the p53/p21 signaling pathway, suggesting the synergistic anti-tumor role of the INO80 complex and miR372. Our results will provide a solid theoretical basis for exploring miR-372 as a biological marker of tumorigenesis.

MicroRNA-372 acts as a double-edged sword in human cancers

MicroRNAs (miRNAs or miRs) are non-coding, single-stranded, endogenous RNAs that regulate various biological processes, most notably the pathophysiology of many human malignancies. It process is accomplished by binding to 3'-UTR mRNAs and controlling gene expression at the post-transcriptional level. As an oncogene, miRNAs can either accelerate cancer progression or slow it down as a tumor suppressor. MicroRNA-372 (miR-372) has been found to have an abnormal expression in numerous human malignancies, implying that the miRNA plays a role in carcinogenesis. It is both increased and downregulated in various cancers, and it serves as both a tumor suppressor and an oncogene. This study examines the functions of miR-372 as well as the LncRNA/CircRNA-miRNA-mRNA signaling pathways in various malignancies and analyses its potential prognostic, diagnostic, and therapeutic implications.

PRDM16, Negatively Regulated by miR-372-3p, Suppresses Cell Proliferation and Invasion in Prostate Cancer

Prostate cancer (PCa) is one of the most prevalent malignant tumors. The alternation of microRNA (miRNA) expression is associated with prostate cancer progression, whereas its way to influence progression of prostate cancer remains elusive. The expression levels of PRDM16 mRNA and miR-372-3p in PCa cell lines were analyzed using qRT-PCR. The protein expression of PRDM16 in PCa cell lines was also analyzed using western blot. CCK-8, wound healing, and Transwell assays were applied to examine cell proliferation, migration, and invasion in prostate cancer cells, respectively. Dual-luciferase reporter assay was utilized to validate the interaction between miR-372-3p and PRDM16. In the present study, markedly decreased PRDM16 mRNA and protein expression levels were observed in prostate cancer cells. PRDM16 overexpression hampered cellular proliferation, migration, and invasion, while silencing PRDM16 had the opposite effect. Moreover, miR-372-3p could target the regulation expression of PRDM16. Rescue experiments demonstrated that upregulating miR-372-3p conspicuously restored the inhibitory effect of increased PRDM16 on cell proliferation, migration, and invasion in PCa. Overall, our study clarifies the biological role of miR-372-3p/PRDM16 axis in prostate cancer progression, which may be effective biomarkers for clinical treatment of prostate cancer.

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.

Nrf2 and Parkin-Hsc70 regulate the expression and protein stability of p62/SQSTM1 under hypoxia

Solid tumors often contain regions with very low oxygen concentrations or hypoxia resulting from altered metabolism, uncontrolled proliferation, and abnormal tumor blood vessels. Hypoxia leads to resistance to both radio- and chemotherapy and a predisposition to tumor metastases. Under hypoxia, sequestosome 1 (SQSTM1/p62), a multifunctional stress-inducible protein involved in various cellular processes, such as autophagy, is down-regulated. The hypoxic depletion of p62 is mediated by autophagic degradation. We herein demonstrated that hypoxia down-regulated p62 in the hepatoma cell line Hep3B at the transcriptional and post-translational levels. At the transcriptional level, hypoxia down-regulated p62 mRNA by inhibiting nuclear factor erythroid 2-related factor 2 (Nrf2). The overexpression of Nrf2 and knockdown of Siah2, a negative regulator of Nrf2 under hypoxia, diminished the effects of hypoxia on p62 mRNA. At the post-translational level, the proteasome inhibitor MG132, but not the lysosomal inhibitors ammonium chloride and bafilomycin, prevented the hypoxic depletion of p62, suggesting the involvement of the proteasome pathway. Under hypoxia, the expression of the E3 ubiquitin ligase Parkin was up-regulated in a hypoxia-inducible factor 1α-dependent manner. Parkin ubiquitinated p62 and led to its proteasomal degradation, ensuring low levels of p62 under hypoxia. We demonstrated that the effects of Parkin on p62 required heat shock cognate 71 kDa protein (Hsc70). We also showed that the overexpression of Nrf2 and knockdown of Parkin or Hsc70 induced the accumulation of p62 and reduced the viability of cells under hypoxia. We concluded that a decrease in p62, which involves regulation at the transcriptional and post-translational levels, is critical for cell survival under hypoxia. The present results show the potential of targeting Nrf2/Parkin-Hsc70-p62 as a novel strategy to eradicate hypoxic solid tumors.

PRDM16, negatively regulated by miR-372-3p, suppresses cell proliferation and invasion in prostate cancer

Prostate cancer (PCa) is one of the most prevalent malignant tumours. The alternation of microRNAs (miRNAs) expression is associated with prostate cancer progression, whereas its way to influence progression of prostate cancer remains elusive. The expression levels of PRDM16 mRNA and miR-372-3p in PCa cell lines were analysed using qRT-PCR. The protein expression of PRDM16 in PCa cell lines was also analysed using Western blot. CCK-8, wound healing and Transwell assays were applied to examine cell proliferation, migration, and invasion in prostate cancer cells, respectively. Dual-luciferase reporter assay was utilised to validate the interaction between miR-372-3p and PRDM16. In the present study, markedly decreased PRDM16 mRNA and protein expression levels were observed in prostate cancer cells. PRDM16 overexpression hampered cellular proliferation, migration, and invasion, while silencing PRDM16 had the opposite effect. Moreover, miR-372-3p could target the regulation expression of PRDM16. Rescue experiments demonstrated that upregulating miR-372-3p conspicuously restored the inhibitory effect of increased PRDM16 on cell proliferation, migration, and invasion in PCa. Overall, our study clarifies the biological role of miR-372-3p/PRDM16 axis in prostate cancer progression, which may be effective biomarkers for clinical treatment of prostate cancer.

Unraveling diverse roles of noncoding RNAs in various human papillomavirus negative cancers

Human papillomavirus (HPV)-negative tumors distinguish from cancers associated with HPV infection. Due to its high rate of lymph node metastasis and difficulty in inchoate discover and diagnosis, the treatment efficacy of HPV-negative cancers is unsatisfactory. Epidemiological evidence suggests that HPV-negative tumor patients have a poor prognosis, and the mortality is higher than that of cancer patients caused by HPV infection. Evidence has demonstrated that noncoding RNAs (ncRNAs) play a crucial role in regulation of physiological and developmental processes. Therefore, dysregulated ncRNAs are involved in the occurrence of diversified diseases, including cancer. In cumulative studies, ncRNAs are concerned with pathogenetic mechanisms of HPV-negative tumors via regulating gene expression and signal transduction. It is important to decipher the functions of ncRNAs in HPV-negative cancers and identify the potential biomarkers, which will bring new treatment strategies for improving outcome of cancer therapy. In this review, we demonstrated the effects of ncRNAs via regulating the development and progression of HPV- negative tumors by directly or indirectly acting on target molecules, which provide a basis for future tumor targeted therapy by targeting ncRNAs for HPV-negative cancers.

MiR-372-3p Functions as a Tumor Suppressor in Colon Cancer by Targeting MAP3K2

MicroRNAs (miRNAs) as small non-coding RNA transcripts bind their complementary sequences in the 3′-untranslated region (3′-UTR) of target messenger RNAs (mRNAs) to regulate their expression. It is known that miR-372 belongs to the miR-371–373 gene cluster and has been found to be abnormally expressed in a variety of cancers, but its precise mechanism in cancer remains to be discovered. In this study, miR-372-3p expression was assessed in 153 frozen tissue samples, including primary diagnosed colon cancer and matched normal and adjacent tissues, using real time quantitative polymerase chain reaction (qPCR). An analysis of qPCR data revealed a significant reduction in miR-372-3p expression (by >2-fold) in colon cancer tissues in 51.5% (34/66) of patients. Consistent with this, mimicking the increased miR-372-3p levels in SW480 colon cancer cells significantly suppressed cell growth and proliferation. Although no direct correlation was found between the low level of miR-372-3p and certain tumor-related factors, such as p53, HRE-2, PMS2, MLH1, MSH2, MSH6, HDAC4, p21, and Wee1, in colon cancer tissues, an inverse relationship between miR-372-3p and Ki67 (a marker of proliferation) or miR-372-3p and MAP3K2(MEKK2), which plays a critical role in the MAPK signaling pathways, was confirmed using tissue samples. The target relationship between miR-372-3p and MAP3K2 was verified using luciferase assays in SW480 colon cancer cells. As expected, miR-372-3p mimics significantly suppressed the luciferase activity of pMIR-luc/MAP3K2 3′-UTR in cells, suggesting that miR-372-3p modulates the expression of MAP3K2 by directly targeting its 3′-UTR. Overall, the results obtained herein suggest that miR-372-3p may function as a tumor-suppressor miRNA in colon cancer by targeting MAP3K2.

The crosstalk between reactive oxygen species and noncoding RNAs: from cancer code to drug role

Oxidative stress (OS), characterized by the excessive accumulation of reactive oxygen species (ROS), is an emerging hallmark of cancer. Tumorigenesis and development driven by ROS require an aberrant redox homeostasis, that activates onco-signaling and avoids ROS-induced programmed death by orchestrating antioxidant systems. These processes are revealed to closely associate with noncoding RNAs (ncRNAs). On the basis of the available evidence, ncRNAs have been widely identified as multifarious modulators with the involvement of several key redox sensing pathways, such as NF-κB and Nrf2 signaling, therefore potentially becoming effective targets for cancer therapy. Furthermore, the vast majority of ncRNAs with property of easy detected in fluid samples (e.g., blood and urine) facilitate clinicians to monitor redox homeostasis, indicating a novel method for cancer diagnosis. Herein, focusing on carcinoma initiation, metastasis and chemoradiotherapy resistance, we aimed to discuss the ncRNAs-ROS network involved in cancer progression, and the potential clinical application as biomarkers and therapeutic targets.

Potential Biomarkers of miR-371-373 Gene Cluster in Tumorigenesis

microRNAs (miRNAs) are small non-coding RNA transcripts (20–24 nucleotides) that bind to their complementary sequences in the 3′-untranslated regions (3′-UTR) of targeted genes to negatively or positively regulate their expression. miRNAs affect the expression of genes in cells, thereby contributing to several important biological processes, including tumorigenesis. Identifying the miRNA cluster as a human embryonic stem cell (hESC)-specific miRNAs initially led to the identification of miR-371, miR-372, miR-373, and miR-373*, which can ultimately be translated into mature miRNAs. Recent evidence suggests that miR-371–373 genes are abnormally expressed in various cancers and act either as oncogenes or tumor suppressors, indicating they may be suitable as molecular biomarkers for cancer diagnosis and prevention. In this article, we summarize recent studies linking miR-371–373 functions to tumorigenesis and speculate on the potential applications of miR-371–373 as biomarkers for cancer diagnosis and treatment.

Sequestosome 1/p62: A multitasker in the regulation of malignant tumor aggression (Review)

Sequestosome 1 (SQSTM1)/p62 is an adapter protein mainly involved in the transportation, degradation and destruction of various proteins that cooperates with components of autophagy and the ubiquitin-proteasome degradation pathway. Numerous studies have shown that SQSTM1/p62 functions at multiple levels, including involvement in genetic stability or modification, post-transcriptional regulation and protein function. As a result, SQSTM1/p62 is a versatile protein that is a critical core regulator of tumor cell genetic stability, autophagy, apoptosis and other forms of cell death, malignant growth, proliferation, migration, invasion, metastasis and chemoradiotherapeutic response, and an indicator of patient prognosis. SQSTM1/p62 regulates these processes via its distinct molecular structure, through which it participates in a variety of activating or inactivating tumor-related and tumor microenvironment-related signaling pathways, particularly positive feedback loops and epithelial-mesenchymal transition-related pathways. Therefore, functioning as a proto-oncogene or tumor suppressor gene in various types of cancer and tumor-associated microenvironments, SQSTM1/p62 is capable of promoting or retarding malignant tumor aggression, giving rise to immeasurable effects on tumor occurrence and development, and on patient treatment and prognosis.

The role of P62 in the development of human thyroid cancer and its possible mechanism

BACKGROUND

Thyroid cancer is the most common malignancy in human endocrine system. Increasing evidence has indicated that p62 plays a key role in tumorigenesis. The roles and underlying molecular mechanisms of P62 in thyroid cancer, however, remain to be elucidated.

METHODS

The expression levels of P62 in thyroid tumor tissues and thyroid cancer cells were detected by western blotting and qRT-PCR. Then, the effects of up-regulation or down-regulation of P62 on thyroid cancer cell proliferation, migration, invasion, cell cycle and apoptosis were measured by CCK-8 assay, transwell assay, flow cytometry and transwell assay, respectively. In terms of the mechanism, P62 could stimulate thyroid cancer progression by the activation of nuclear factor-kappa B (NF-κB) signaling pathway.

RESULTS

P62 was highly expressed in thyroid tumor tissues. Furthermore, high expression of p62 was observed in PTC cell lines, and especially in the K1 and TPC-1 cells. In vitro, the up-regulation of p62 promoted cell proliferation, migration, and invasion of thyroid cancer cells, whereas the knockdown of p62 resulted in the opposite effect. Knock-down of P62 increased the number of cells in the G0/G1 phase but reduced it in the S and G2/M phase. Moreover, we confirmed that overexpression of p62 inactivated NF-κB pathway with sequencing analysis and bioinformatics analysis.

CONCLUSION

This research work suggested that p62 could promote PTC cell proliferation, migration, and invasion via NF-κB signaling pathway. Furthermore, p62 is a potential biomarker which might be closely related to the tumorigenesis in PTC. Its potential role as a therapeutic target for PTC is worthy of further study.

Aberrant miR-10b, miR-372, and miR-375 expression in the cytobrushed samples from oral potentially malignant disorders

Background/purpose

MicroRNA (miRNA) alterations play important roles in the neoplastic process of oral squamous cell carcinoma (OSCC). Upregulation of miR-10b and miR-372 and downregulation of miR-375 are frequent events in OSCC. The aberrances of these miRNAs in oral potentially malignant lesions (OPMD) were studied to determine their status during the establishment of OSCC.

Materials and methods

Cytobrushed sampling was used to collect epithelial cells from 11 OSCC and 34 OPMD lesions and matched normal mucosa. The expression levels of miR-10b, miR-372, and miR-375 were analyzed using quantitative reverse transcription polymerase chain reaction analysis. The clinical implications of these aberrances were further investigated.

Results

Both miR-10b and miR-372 were upregulated in OPMD, but only miR-10b expression was upregulated in OSCC comparing to control. miR-375 was downregulated in OPMD and tended to be downregulated in OSCC. Dysplastic OPMD could be distinguished based on miR-372 expression level; miR-375 expression levels facilitated discrimination between OPMD and OSCC. The combined analysis of miR-375 and miR-372 remarkably enhanced the accuracy of differentiating OPMD from OSCC.

Conclusion

Aberrant miR-10b. miR-372, and miR-375 expression occurs early during oral carcinogenesis. The detection of miR-372 and miR-375 expression using cytobrush samples may assist in differentiating between OPMD and OSCC.

Sirt1 deacetylates and stabilizes p62 to promote hepato-carcinogenesis

p62/SQSTM1 is frequently up-regulated in many cancers including hepatocellular carcinoma. Highly expressed p62 promotes hepato-carcinogenesis by activating many signaling pathways including Nrf2, mTORC1, and NFκB signaling. However, the underlying mechanism for p62 up-regulation in hepatocellular carcinoma remains largely unclear. Herein, we confirmed that p62 was up-regulated in hepatocellular carcinoma and its higher expression was associated with shorter overall survival in patients. The knockdown of p62 in hepatocellular carcinoma cells decreased cell growth in vitro and in vivo. Intriguingly, p62 protein stability could be reduced by its acetylation at lysine 295, which was regulated by deacetylase Sirt1 and acetyltransferase GCN5. Acetylated p62 increased its association with the E3 ligase Keap1, which facilitated its poly-ubiquitination-dependent proteasomal degradation. Moreover, Sirt1 was up-regulated to deacetylate and stabilize p62 in hepatocellular carcinoma. Additionally, Hepatocyte Sirt1 conditional knockout mice developed much fewer liver tumors after Diethynitrosamine treatment, which could be reversed by the re-introduction of exogenous p62. Taken together, Sirt1 deacetylates p62 at lysine 295 to disturb Keap1-mediated p62 poly-ubiquitination, thus up-regulating p62 expression to promote hepato-carcinogenesis. Therefore, targeting Sirt1 or p62 is a reasonable strategy for the treatment of hepatocellular carcinoma.

Salivary Micro-RNA and Oral Squamous Cell Carcinoma: A Systematic Review

Oral squamous cell carcinoma (OSCC) is a widespread malignancy with high mortality. In particular, a delay in its diagnosis dramatically decreases the survival rate. The aim of this systematic review was to investigate and summarize clinical results in the literature, regarding the potential use of salivary microRNAs (miRNAs) as diagnostic and prognostic biomarkers for OSCC patients. Twelve papers were selected, including both case-control and cohort studies, and all of them detected significantly dysregulated miRNAs in OSCC patients compared to healthy controls. Based on our results, salivary miRNAs might provide a non-invasive and cost-effective method in the diagnosis of OSCC, and also to monitor more easily its evolution and therapeutic response and therefore aid in the establishment of specific therapeutic strategies.

Activation of the miR-371/372/373 miRNA Cluster Enhances Oncogenicity and Drug Resistance in Oral Carcinoma Cells

Oral squamous cell carcinoma (OSCC) is among the leading causes of cancer-associated deaths worldwide. Family members in miR-371/372/373 miRNA cluster, which is localized at human chromosome 19q13.4, are co-expressed in both human stem cells and malignancies. The individual miRNA in this cluster are also involved in modulating the pathogenesis of malignancies as either oncogenes or suppressors. The 19q13 region is frequently gained in head and neck cancers. High expression of miR-372 and miR-373 are survival predictors for OSCC. However, the role of the miR-371/372/373 cluster in oral carcinogenesis remains to be fully investigated. We use the clustered, regularly interspaced, short palindromic repeats (CRISPR)-Cas9 system to establish OSCC cell subclones that had the miR-371/372/373 cluster deleted. In addition, further subclones were established that had the promoter of this cluster deleted. Concordant silencing in SAS cells of miR-371/372/373 decreased oncogenic potential, increased cisplatin sensitivity, activated p53, and upregulated the expression of Bad and DKK1. We also employed the CRISPR/dCas9 synergistic activation mediator system, which allowed robust transcriptional activation of the whole miR-371/372/373 cistron. Upregulation of endogenous miR-371/372/372 expression increased both oncogenicity and drug resistance. These were accompanied by a slight activation of AKT, β-catenin, and Src. This study identifies the oncogenic role of the miR-371/372/373 cluster in OSCC. Using CRISPR based strategy can be a powerful paradigm that will provide mechanistic insights into miRNA cluster functionality, which will also likely help the development of targeting options for malignancies.

Targeting autophagy to overcome drug resistance: further developments

Inhibiting cell survival and inducing cell death are the main approaches of tumor therapy. Autophagy plays an important role on intracellular metabolic homeostasis by eliminating dysfunctional or unnecessary proteins and damaged or aged cellular organelles to recycle their constituent metabolites that enable the maintenance of cell survival and genetic stability and even promotes the drug resistance, which severely limits the efficacy of chemotherapeutic drugs. Currently, targeting autophagy has a seemingly contradictory effect to suppress and promote tumor survival, which makes the effect of targeting autophagy on drug resistance more confusing and fuzzier. In the review, we summarize the regulation of autophagy by emerging ways, the action of targeting autophagy on drug resistance and some of the new therapeutic approaches to treat tumor drug resistance by interfering with autophagy-related pathways. The full-scale understanding of the tumor-associated signaling pathways and physiological functions of autophagy will hopefully open new possibilities for the treatment of tumor drug resistance and the improvement in clinical outcomes.

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.

Revisiting cancer hallmarks: insights from the interplay between oxidative stress and non-coding RNAs

Cancer is one of the most common disease worldwide, with complex changes and certain traits which have been described as “The Hallmarks of Cancer.” Despite increasing studies on in-depth investigation of these hallmarks, the molecular mechanisms associated with tumorigenesis have still not yet been fully defined. Recently, accumulating evidence supports the observation that microRNAs and long noncoding RNAs (lncRNAs), two main classes of noncoding RNAs (ncRNAs), regulate most cancer hallmarks through their binding with DNA, RNA or proteins, or encoding small peptides. Reactive oxygen species (ROS), the byproducts generated during metabolic processes, are known to regulate every step of tumorigenesis by acting as second messengers in cancer cells. The disturbance in ROS homeostasis leads to a specific pathological state termed “oxidative stress”, which plays essential roles in regulation of cancer progression. In addition, the interplay between oxidative stress and ncRNAs is found to regulate the expression of multiple genes and the activation of several signaling pathways involved in cancer hallmarks, revealing a potential mechanistic relationship involving ncRNAs, oxidative stress and cancer. In this review, we provide evidence that shows the essential role of ncRNAs and the interplay between oxidative stress and ncRNAs in regulating cancer hallmarks, which may expand our understanding of ncRNAs in the cancer development from the new perspective.

Clinical significance of miR-372 and miR-495 in acute myeloid leukemia

The present study aimed to explore the clinical significance of miR-372 and miR-495 in acute myeloid leukemia (AML). Eighty-one AML patients (research group) admitted to the First Hospital of Lanzhou University from March 2012 to January 2014 were selected, and 60 healthy persons (control group) were selected. The expression levels of miR-372 and miR-495 in the peripheral blood of the subjects were detected by reverse transcriptase quantitative PCR, and their diagnostic and prognostic values in AML were analyzed. The miR-372 expression level in the peripheral blood of patients in the research group was significantly higher than that in the control group (P<0.05), and the miR-495 level was significantly lower than that in the control group (P<0.05). The area under the curve (AUC), sensitivity, and specificity of miR-372 combined with miR-495 in the diagnosis of AML were 0.925, 86.43, and 93.33% respectively. The 5-year survival rate of patients with high expression of miR-372 was lower than that of those with low expression of miR-372 (P<0.05), and the 5-year survival rate of patients with high expression of miR-495 was higher than that of those with low expression of miR-495 (P<0.05). miR-372 and miR-495 were independent risk factors for the prognosis and survival of AML patients. miR-372 expression increased in AML, while miR-495 decreased. miR-372 and miR-495 are effective indicators for the early diagnosis and prognosis of AML.

MicroRNA Targeting Nicotinamide Adenine Dinucleotide Phosphate Oxidases in Cancer

Significance: Reactive oxygen species (ROS) production occurs primarily in the mitochondria as a by-product of cellular metabolism. ROS are also produced by nicotinamide adenine dinucleotide phosphate (NADPH) oxidases in response to growth factors and cytokines by normal physiological signaling pathways. NADPH oxidase, a member of NADPH oxidase (NOX) family, utilizes molecular oxygen (O₂) to generate ROS such as hydrogen peroxide and superoxide. Imbalance between ROS production and its elimination is known to be the major cause of various human diseases. NOX family proteins are exclusively involved in ROS production, which makes them attractive target(s) for the treatment of ROS-mediated diseases including cancer. Recent Advances: Molecules such as Keap1/nuclear factor erythroid 2-related factor 2 (Nrf2), N-methyl-d-aspartic acid (NMDA) receptors, nuclear factor-kappaB, KRAS, kallistatin, gene associated with retinoic-interferon-induced mortality-19, and deregulated metabolic pathways are involved in ROS production in association with NADPH oxidase. Critical Issues: Therapeutic strategies targeting NADPH oxidases in ROS-driven cancers are not very effective due to its complex regulatory circuit. Tumor suppressor microRNAs (miRNAs) viz. miR-34a, miR-137, miR-99a, and miR-21a-3p targeting NADPH oxidases are predominantly downregulated in ROS-driven cancers. miRNAs also regulate other cellular machineries such as Keap1/Nrf2 pathway and NMDA receptors involved in ROS production and consequently drug resistance. Here, we discuss the structure, function, and metabolic role of NADPH oxidase, NOX family protein-protein interaction, their association with other pathways, and NADPH oxidase alteration by miRNAs. Moreover, we also discuss and summarize studies on NADPH oxidase associated with various malignancies and their therapeutic implications. Future Directions: Targeting NADPH oxidases through miRNAs appears to be a promising strategy for the treatment of ROS-driven cancer.

The miR-372-ZBTB7A Oncogenic Axis Suppresses TRAIL-R2 Associated Drug Sensitivity in Oral Carcinoma

miR-372 has been shown a potent oncogenic miRNA in the pathogenesis of oral squamous cell carcinoma (OSCC). The zinc finger and BTB domain containing 7A protein (ZBTB7A) is a transcriptional regulator that is involved in a great diversity of physiological and oncogenic regulation. However, the modulation of ZBTB7A in OSCC remains unclear. Tissue analysis identifies a reverse correlation in expression between miR-372 and ZBTB7A in OSCC tumors. When OSCC cells have stable knockdown of ZBTB7A, their oncogenic potential and drug resistance is increased. By way of contrast, such an increase is attenuated by expression of ZBTB7A. Screening and validation confirms that ZBTB7A is able to modulate expression of the death receptors TRAIL-R1, TRAIL-R2, Fas and p53 phosphorylated at serine-15. In addition, ZBTB7A transactivates TRAIL-R2, which sensitizes cells to cisplatin-induced apoptosis. The ZBTB7A-TRAIL-R2 cascade is involved in both the extrinsic and intrinsic cisplatin-induced pathways of apoptosis. Database analysis indicates that the expression level of and the copy status of ZBTB7A and TRAIL-R2 are important survival predictors for head and neck cancers. Collectively, this study indicates the importance of the miR-372-ZBTB7A-TRAIL-R2 axis in mediating OSCC pathogenesis and in controlling OSCC drug resistance. Therefore, silencing miR-372 and/or upregulating ZBTB7A would seem to be promising strategies for enhancing the sensitivity of OSCC to cisplatin therapy.

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.

FAT1 somatic mutations in head and neck carcinoma are associated with tumor progression and survival

In recent years, the incidence and mortality rates of head and neck squamous cell carcinoma (HNSCC) have increased worldwide. Therefore, understanding genomic alterations in HNSCC carcinogenesis is crucial for appropriate diagnosis and therapy. Protocadherin FAT1, which encodes 4588 amino acid residues, regulates complex mechanisms to promote oncogenesis or suppression of malignancies. Multiplex PCR-based next-generation sequencing (NGS) revealed FAT1 somatic mutations. The clinicopathologic implications of FAT1 in HNSCC were investigated using expression assays, and the functional role of FAT1 in HNSCC pathogenesis was determined using ectopic expression and knockdown experiments. Approximately 29% patients with HNSCC harbored damaging FAT1 mutations. InVEx algorithm identified FAT1 as a significant functional mutation burden. Each type of mutation (missense, nonsense and frameshift) accounted for nearly one-third of deleterious mutations. FAT1 mutations correlated with lower FAT1 expression in tumors. The knockdown of the endogenous expression of FAT1 and exogenous expression of crucial FAT1 domains unequivocally indicated that FAT1 suppressed the migration and invasion capability of HNSCC cells. Functional analysis suggested that nonsense mutations in FAT1 result in the loss of the suppression of tumor progression. FAT1 mutations and downregulation defined nodal involvement, lymphovascular permeation and tumor recurrence. In addition, FAT1 mutations and downregulation are independent predictors of poor disease-free survival in patients with HNSCC. This study is the first to perform multiplex PCR-based NGS to indicate marked non-synonymous FAT1 mutations in HNSCC, which are prognostic indicators. The gene analysis strategy proposed for detecting FAT1 mutations may be a valid method for mutation screening.

Epithelial-mesenchymal transition and microRNAs: Challenges and future perspectives in oral cancer

BACKGROUND

Head and neck cancer is the sixth most common cancer worldwide, with oral squamous cell carcinoma (OSCC) being the most representative type. OSCC is a public health problem with high morbidity and poor survival rate. Epithelial-mesenchymal transition is emerging as a hallmark in OSCC.

METHODS

In this study, we described the role of microRNAs in epithelial-mesenchymal transition regulation in OSCC based on a PubMed search using articles published in English between January 1, 2010, and January 31, 2018.

RESULTS

MicroRNA's regulatory networks seem to be a hallmark of epithelial-mesenchymal transition in OSCC pathophysiology becoming a growing challenge to design new studies and strategies from biology to clinical applications.

CONCLUSION

Therefore, we propose that targeting therapies to epithelial-mesenchymal transition-type cells, namely, coordinating microRNAs and/or hydrophobic drugs, such as conventional therapy, could be a promising strategy to improve the outcomes of patients with OSCC.

HistoneH3 demethylase JMJD2A promotes growth of liver cancer cells through up-regulating miR372

Changes in histone lysine methylation status have been observed during cancer formation. JMJD2A protein is a demethylase that is overexpressed in several tumors. Herein, our results demonstrate that JMJD2A accelerates malignant progression of liver cancer cells in vitro and in vivo. Mechanistically, JMJD2A promoted the expression and mature of pre-miR372 epigenetically. Notably, miR372 blocks the editing of 13th exon-introns-14th exon and forms a novel transcript(JMJD2AΔ) of JMJD2A. In particular, JMJD2A inhibited P21(WAF1/Cip1) expression by decreasing H3K9me3 dependent on JMJD2AΔ. Thereby, JMJD2A could enhance Pim1 transcription by suppressing P21(WAF1/Cip1). Furthermore, through increasing the expression of Pim1, JMJD2A could facilitate the interaction among pRB, CDK2 and CyclinE which prompts the transcription and translation of oncogenic C-myc. Strikingly, JMJD2A may trigger the demethylation of Pim1. On the other hand, Pim1 knockdown and P21(WAF1/Cip1) overexpression fully abrogated the oncogenic function of JMJD2A. Our observations suggest that JMJD2A promotes liver cancer cell cycle progress through JMJD2A-miR372-JMJD2AΔ-P21WAF1/Cip1-Pim1-pRB-CDK2-CyclinE-C-myc axis. This study elucidates a novel mechanism for JMJD2A in liver cancer cells and suggests that JMJD2A can be used as a novel therapeutic targets of liver cancer.

miR372 Promotes Progression of Liver Cancer Cells by Upregulating erbB-2 through Enhancement of YB-1

MicroRNAs are known to be involved in carcinogenesis. Recently, microRNA-372 (miR372) has been proven to play a substantial role in several human cancers, but its functions in liver cancer remain unclear. Herein, our results demonstrate that miR372 accelerates growth of liver cancer cells in vitro and in vivo. Mechanistically, miR372 enhances expression of Y-box-binding protein 1 (YB-1) by targeting for phosphatase and tensin homolog (PTEN) directly and consequently promotes phosphorylation of YB-1 via HULC looping dependent on ERK1/2 and PTEN. In particular, HULC knockdown or PTEN overexpression abrogated this miR372 action. Moreover, miR372 inhibits the degradation of β-catenin dependent on phosphorylation of YB-1 and then enhances the expression and activity of pyruvate kinase M2 isoform (PKM2) by β-catenin-LEF/TCF4 pathway. Furthermore, the loading of LEF/TCF4 on PKM2 promoter region was significantly increased in miR372 overexpressing Hep3B, and thus, glycolytic proton efflux rate (glycoPER) was significantly increased in rLV-miR372 group compared to the rLV group. Moreover, β-catenin knockdown abrogates this function of miR372. Ultimately, miR372 promotes the expression of erbB-2 through PKM2-pH3T11-acetylation on histone H3 lysine 9 (H3K9Ac) pathway. Of significance, both YB-1 knockdown and erbB-2 knockdown abrogate oncogenic action of miR372. Our observations suggest that miR372 promotes liver cancer cell cycle progress by activating cyclin-dependent kinase 2 (CDK2)-cyclin E-P21/Cip1 complex through miR372-YB-1-β-catenin-LEF/TCF4-PKM2-erbB-2 axis. This study elucidates a novel mechanism for miR372 in liver cancer cells and suggests that miR372 can be used as a novel therapeutic target of liver cancer.

Up-regulation of miR-187 modulates the advances of oral carcinoma by targeting BARX2 tumor suppressor

Oral squamous cell carcinoma (OSCC) is one of the most common cancers worldwide. Aberrations in miRNA regulation are known to play important roles in OSCC pathogenesis. miR-187 was shown to be up-regulated in head and neck malignancies in our previous screening. This study further investigated the oncogenic potential, clinical implications, and targets of miR-187 in OSCC. We observed that miR-187 increased oncogenicity, particularly migration, of OSCC cells. miR-187 expression increased the xenografic tumorigenicity and metastasis in mice. In addition, metastatic human OSCC had higher miR-187 expression than did non-metastatic tumors. Through vigorous screening, we confirmed BarH-like Homeobox 2 (BARX2) gene as an miR-187 target. BARX2 expression suppressed the migration, invasion, anchorage-independent colony formation, and orthotopic tumorigenesis of OSCC cells. The migratory phenotype and neck metastasis induced by miR-187 was rescued by BARX2 expression. BARX2 expression was down-regulated in the vast majority of OSCC, and this down-regulation was particularly conspicuous in tumors with advanced nodal metastasis. In addition, plasma miR-187 was significantly higher in OSCC patients than in normal individuals. This study highlights the roles of miR-187-BARX2 in driving the carcinogenesis of OSCC. The results suggest that miR-187 is a potential serological marker for OSCC and that targeting of miR-187 might prove effective in attenuating nodal metastasis.

miR-372 promotes breast cancer cell proliferation by directly targeting LATS2

MicroRNAs (miRs) have previously been demonstrated to be important in the tumorigenesis and progression of breast cancer. miR-372 was previously revealed to be involved in various types of human cancer, however its function in breast cancer remains largely unknown. The present study demonstrated that miR-372 is frequently overexpressed in breast cancer cell lines and tissues. The downregulation of miR-372 markedly inhibited cell proliferation, arrested the cell cycle in the G1/S phase, and increased the apoptosis of breast cancer cells. Consistently, an in vivo xenograft study also demonstrated the suppressive effects of miR-372 knockdown on tumor growth. Further studies revealed that miR-372 modulated the expression of large tumor suppressor kinase 2 (LATS2) by directly targeting its 3′-untranslated region in breast cancer cells. Furthermore, silencing of LATS2 was able to rescue the effect of the miR-372 inhibitor. Overall, the results suggest that miR-372 functions as an oncogenic miRNA in breast cancer by targeting LATS2.

Role of non-coding RNAs in head and neck squamous cell carcinoma: A narrative review

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide with high recurrence, metastasis, and poor treatment outcome. Recent studies have reported that non-coding RNA (ncRNA) might play critical role in regulating different types of cancer. MicroRNAs (miRs) are short ncRNAs (20-25 nucleotides) responsible for post-transcriptional regulation of gene expression and may have a role in oncogenesis by acting as oncomiRs or tumor suppressor miRs. Long non-coding RNAs (lncRNAs) are heterogenous group of ncRNAs more than 200 nucleotides long, can act in cis and/or in trans, and have been also implicated in carcinogenesis. These molecules have been suggested to be promising candidates as diagnostic and prognostic biomarkers and for development of novel therapeutic approaches. In this review, we have summarized recent findings on role of these ncRNAs in HPV-negative (HPV-ve) and HPV-positive (HPV+ve) HNSCC. The available literature supports differential expression of both microRNAs and long non-coding RNAs, which include oncogenic ncRNAs (miR-21, miR-31, miR-155, miR-211, HOTAIR, and MALAT1) and tumor suppressor ncRNAs (let7d, miR-17, miR-375, miR-139, and MEG3) in HPV+ve HNSCC tumors as compared to HPV-ve tumors and they have distinct role in the pathophysiology of these two types of HNSCCs.

Downregulation of ULK1 by microRNA-372 inhibits the survival of human pancreatic adenocarcinoma cells

Dysregulation of microRNA (miRNA) expression in various cancers and their role in cancer progression is well documented. The purpose of this study was to investigate the biological role of miR‐372 in human pancreatic adenocarcinoma (HPAC). We collected 20 pairs of HPAC tissues and adjacent non‐cancerous tissues to detect miR‐372 expression levels. We transfected BXPC‐3 and PANC‐1 cells with miR‐372 inhibitor/mimics to study their effect on cell proliferation, apoptosis, invasion, migration and autophagy. In addition, miR‐372 mimics and a tumor protein UNC51‐like kinase 1 (ULK1) siRNA were co‐transfected into BXPC‐3 and PANC‐1 cells to explore the mechanism of miR‐372 and ULK1 on HPAC tumorigenesis. We found that the expression of miR‐372 was markedly downregulated in HPAC cells compared to adjacent normal tissues. Furthermore, functional assays showed that miR‐372 inhibited cell proliferation, invasion, migration and autophagy in BXPC‐3 and PANC‐1 cells. An inverse correlation between miR‐372 expression and ULK1 expression was observed in HPAC tissues. Downregulation of ULK1 inhibited the overexpression effects of miR‐372, and upregulation of ULK1 reversed the effects of overexpressed miR‐372. Finally, we found that silencing ULK1 or inhibiting autophagy partly rescued the effects of miR‐372 knockdown in HPAC cells, which may explain the influence of miR‐372/ULK1 in HPAC development. Taken together, these results revealed a significant role of the miR‐372/ULK1 axis in suppressing HPAC cell proliferation, migration, invasion and autophagy.

MicroRNA-372 inhibits endometrial carcinoma development by targeting the expression of the Ras homolog gene family member C (RhoC)

Here we explore the role of microRNA-372 (miR-372) in tumorigenesis and development of endometrial adenocarcinoma (EC) and analyze the underlying mechanism. We found that miR-372 expression is much lower in EC than normal endometrial specimens. Cell function experiments demonstrated that miR-372 overexpression suppressed cell proliferation, migration, and invasion, and led to a G1 phase arrest and promoted the apoptosis of endometrial carcinoma cells in vitro. The nude mouse xenograft assay demonstrated that miR-372 overexpression suppressed tumor growth. RT-PCR and Western blot assays detected the expression of known targets of miR-372 in other malignant tumors and found Cyclin A1 and Cyclin-dependent Kinase 2 (CDK2) was downregulated by miR-372. Bioinformatic predictions and dual-luciferase reporter assays found that RhoC was a possible target of miR-372. RT-PCR and Western blot assays demonstrated that miR-372 transfection reduced the expression of RhoC, matrix metalloproteinase 2 (MMP2) and MMP9, while it increased the expression of cleaved poly (ADP ribose) polymerase (PARP) and bcl-2-associated X protein (Bax). The cell function experiments that transfected siRNA with RhoC showed the same trend as those which were transfected with miR-372. Taken together, our results demonstrated for the first time that miR-372 suppresses tumorigenesis and the development of EC; RhoC is a new and potentially important therapeutic target.

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.

p62/SQSTM1-Dr. Jekyll and Mr. Hyde that prevents oxidative stress but promotes liver cancer

p62/SQSTM1 is a multifunctional signaling hub and autophagy adaptor with many binding partners, which allow it to activate mTORC1-dependent nutrient sensing, NF-κB-mediated inflammatory responses, and the NRF2-activated antioxidant defense. p62 recognizes polyubiquitin chains via its C-terminal domain and binds to LC3 via its LIR motif, thereby promoting the autophagic degradation of ubiquitinated cargos. p62 accumulates in many human liver diseases, including nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC), where it is a component of Mallory-Denk bodies and intracellular hyaline bodies. Chronic p62 elevation contributes to HCC development by preventing oncogene-induced senescence and death of cancer-initiating cells and enhancing their proliferation. In this review, we discuss p62-mediated signaling pathways and their roles in liver pathophysiology, especially NASH and HCC.

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.

Upregulation of miR-372 and -373 associates with lymph node metastasis and poor prognosis of oral carcinomas

OBJECTIVES/HYPOTHESIS

Oral squamous cell carcinoma (OSCC) is prevalent worldwide, and survival in OSCC has not improved significantly in the last few decades. MicroRNAs (miRNAs) have an important regulatory role in human cancer, including oral carcinogenesis. MiR-372 and miR-373 perform oncogenic and tumor-suppressive functions of between different human malignancies. This study investigated the miR-372 and miR-373 expression and their clinical implication in OSCC.

METHODS

Fifty patients with primary OSCC were included in the study. Primary cancer cells and matched normal oral epithelium were purified by laser capture microdissection. RNA were extracted from these samples. The expression levels of miR-372 and miR-373 in the tissue of OSCC patients were measured by quantitative reverse transcription polymerase chain reaction. The large tumor suppressor kinase 2 (LATS2) protein expression level was measured by Western blotting.

RESULTS

Both miR-372 and miR-373 was up-regulated in OSCC tissue relative to control mucosa. Among different clinical variables, over-expression of miR-372 and miR-373 were associated with nodal metastasis, lymphovascular invasion, and poor survival. Multivariate analysis showed that both high miR-372 and miR-373 expression were independent predictors for poor survival in OSCC. MiR-372 regulated LATS2 expression in OSCC cell lines. LATS2 expression levels are inversely correlated miR-372 in OSCC tissues.

CONCLUSION

Over-expression of miR-372 and miR-373 indicate worse survival in OSCC.

LEVEL OF EVIDENCE

N/A.