HOXA11-AS promotes the progression of oral squamous cell carcinoma by targeting the miR-518a-3p/PDK1 axis

Towards system genetics analysis of head and neck squamous cell carcinoma using the mouse model, cellular platform, and clinical human data

Head and neck squamous cell cancer (HNSCC) is a leading global malignancy. Every year, More than 830 000 people are diagnosed with HNSCC globally, with more than 430 000 fatalities. HNSCC is a deadly diverse malignancy with many tumor locations and biological characteristics. It originates from the squamous epithelium of the oral cavity, oropharynx, nasopharynx, larynx, and hypopharynx. The most frequently impacted regions are the tongue and larynx. Previous investigations have demonstrated the critical role of host genetic susceptibility in the progression of HNSCC. Despite the advances in our knowledge, the improved survival rate of HNSCC patients over the last 40 years has been limited. Failure to identify the molecular origins of development of HNSCC and the genetic basis of the disease and its biological heterogeneity impedes the development of new therapeutic methods. These results indicate a need to identify more genetic factors underlying this complex disease, which can be better used in early detection and prevention strategies. The lack of reliable animal models to investigate the underlying molecular processes is one of the most significant barriers to understanding HNSCC tumors. In this report, we explore and discuss potential research prospects utilizing the Collaborative Cross mouse model and crossing it to mice carrying single or double knockout genes (e.g. Smad4 and P53 genes) to identify genetic factors affecting the development of this complex disease using genome-wide association studies, epigenetics, microRNA, long noncoding RNA, lncRNA, histone modifications, methylation, phosphorylation, and proteomics.

lncRNA HOXA11-AS maintains the stemness of oral squamous cell carcinoma stem cells and reduces the radiosensitivity by targeting miR-518a-3p/PDK1

OBJECTIVE

Oral squamous cell carcinoma (OSCC) is the most prevailing oral malignancy. The lncRNA HOXA11-AS shows prominent roles in OSCC. This study explored the effects of lncRNA HOXA11-AS on regulating OSCC stem cell stemness and radiosensitivity by targeting miR-518a-3p/PDK1.

METHODS

Human OSCC cell lines SCC9 and SCC15 were selected. CD133⁺ cancer stem cells (CSCs) were sorted by immunomagnetic beads. CD133 expression in cells and HOXA11-AS expression in SCC9, SCC15, and CD133⁺ SCC9, CD133⁺ SCC15 cells were assessed by flow cytometry and RT-qPCR. HOXA11-AS was silenced/overexpressed in SCC9, SCC15, CD133⁺ SCC9, and CD133⁺ SCC15 cells. Cell proliferation, radiosensitivity, invasion, and stem cell sphere formation ability were examined by CCK-8, colony formation, Transwell, and stem cell sphere formation. The levels of stemness-related genes (Oct4, Nanog, Sox2), miR-518a-3p, epithelial-mesenchymal transition (EMT)-related proteins (E-cadherin, Vimentin, N-cadherin), and PDK1 were assessed by RT-qPCR and Western blot assay.

RESULTS

HOXA11-AS was up-regulated in SCC9, SCC15, CD133⁺ SCC9, and CD133⁺ SCC15 cells. HOXA11-AS silencing inhibited OSCC proliferation and invasion and enhanced radiosensitivity. HOXA11-AS maintained CSC stemness in OSCC. HOXA11-AS silencing reduced CD133⁺ SCC9 and CD133⁺ SCC15 stem cell sphere formation ability, reduced stem cell stemness-related gene levels, and inhibited EMT. HOXA11-AS regulated OSCC stem cell stemness and radiosensitivity by targeting miR-518a-3p. PDK1 overexpression annulled the regulatory effects of HOXA11-AS silencing on OSCC cell stem cell stemness and radiosensitivity.

CONCLUSION

In vitro lncRNA HOXA11-AS silencing inhibited OSCC stem cell stemness by targeting the miR-518a-3p/PDK1 axis, thus enhancing OSCC cell radiosensitivity.

Screening and identification of miR-181a-5p in oral squamous cell carcinoma and functional verification in vivo and in vitro

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a common malignant tumor associated with poor prognosis. MicroRNAs (miRNAs) play crucial regulatory roles in the cancer development. However, the role of miRNAs in OSCC development and progression is not well understood.

METHODS

We sought to establish a dynamic Chinese hamster OSCC animal model, construct miRNA differential expression profiles of its occurrence and development, predict its targets, and perform functional analysis and validation in vitro.

RESULTS

Using expression and functional analyses, the key candidate miRNA (miR-181a-5p) was selected for further functional research, and the expression of miR-181a-5p in OSCC tissues and cell lines was detected. Subsequently, transfection technology and a nude mouse tumorigenic model were used to explore potential molecular mechanisms. miR-181a-5p was significantly downregulated in human OSCC specimens and cell lines, and decreased miR-181a-5p expression was observed in multiple stages of the Chinese hamster OSCC animal model. Moreover, upregulated miR-181a-5p significantly inhibited OSCC cell proliferation, colony formation, invasion, and migration; blocked the cell cycle; and promoted apoptosis. BCL2 was identified as a target of miR-181a-5p. BCL2 may interact with apoptosis- (BAX), invasion- and migration- (TIMP1, MMP2, and MMP9), and cell cycle-related genes (KI67, E2F1, CYCLIND1, and CDK6) to further regulate biological behavior. Tumor xenograft analysis indicated that tumor growth was significantly inhibited in the high miR-181a-5p expression group.

CONCLUSION

Our findings indicate that miR-181a-5p can be used as a potential biomarker and provide a novel animal model for mechanistic research on oral cancer.

HOX cluster-embedded lncRNAs and epithelial-mesenchymal transition in cancer: Molecular mechanisms and therapeutic opportunities

Although there has been substantial improvement in the treatment modalities, cancer remains the major cause of fatality worldwide. Metastasis, recurrence, and resistance to oncological therapies are the leading causes of cancer mortality. Epithelial-mesenchymal transition (EMT) is a complex biological process that allows cancer cells to undergo morphological transformation into a mesenchymal phenotype to acquire invasive potential. It encompasses reversible and dynamic ontogenesis by neoplastic cells during metastatic dissemination. Hence, understanding the molecular landscape of EMT is imperative to identify a reliable clinical biomarker to combat metastatic spread. Accumulating evidence reveals the role of HOX (homeobox) cluster-embedded long non-coding RNAs (lncRNAs) in EMT and cancer metastasis. They play a crucial role in the induction of EMT, modulating diverse biological targets. The present review emphasizes the involvement of HOX cluster-embedded lncRNAs in EMT as a molecular sponge, chromatin remodeler, signaling regulator, and immune system modulator. Furthermore, the molecular mechanisms behind therapy resistance and the potential use of novel drugs targeting HOX cluster-embedded lncRNAs in the clinical management of distant metastasis will be discussed.

Effects of lncRNA HOXA11-AS on Sevoflurane-Induced Neuronal Apoptosis and Inflammatory Responses by Regulating miR-98-5p/EphA4

Objective

To explore the molecular mechanism of sevoflurane-induced neurotoxicity and to determine whether lncRNA HOXA11-AS affects sevoflurane-induced neuronal apoptosis and inflammation by regulating miR-98-5p/EphA4.

Methods

Morris water maze (MWM) test was used to detect the learning and memory ability of rats, HE staining was used to observe hippocampal pathology, TUNEL staining was used to detect the level of neuronal apoptosis, and RT-qPCR was used to detect the expression of HOXA11-AS, miR-98-5p, IL-6, IL-1β, and TNF-α. At the same time, the contents of IL-6, IL-1β, and TNF-α in serum were detected by ELISA. The expressions of apoptosis-related proteins EphA4, Bax, Cleaved caspase 3, and Bcl-2 were detected by Western blot. The dual-luciferase gene reporter verified the targeting relationship between HOXA11-AS and miR-98-5p and the targeting relationship between miR-98-5p and EphA4.

Results

The expression of HOXA11-AS was observed in sevoflurane-treated rats or cells and promoted neuronal apoptosis and inflammation. HOXA11-AS was knocked out alone, or miR-98-5p was overexpressed which attenuates neuronal apoptosis and inflammatory inflammation after sevoflurane treatment. Furthermore, knockdown of HOXA11-AS alone was partially restored by knockdown of miR-98-5p or overexpression of EphA4.

Conclusion

Inhibition of lncRNA HOXA11-AS attenuates sevoflurane-induced neuronal apoptosis and inflammatory responses via miR-98-5p/EphA4.

Long noncoding RNA NNT-AS1 inhibits IL-17-induced proliferation, migration, and invasion of gastric cancer cells by regulating miR-518a-3p

BACKGROUND

Interleukin 17 (IL-17) is a cytokine secreted in many cell types, which is related to the development of tumor cells. The expression of the long noncoding RNA (lncRNA) nicotinamide nucleotide transhydrogenase antisense RNA1 (NNT-AS1) is up-regulated in gastric cancer tissues. NNT-AS1 may inhibit the proliferation and invasion of gastric cancer cells and arrest cell cycle progression by reducing the expression of miR-363. The regulatory mechanism of NNT-AS1 and IL-17 on gastric cancer cells is still not completely clear.

AIM

To explore the molecular mechanism by which NNT-AS1 inhibits IL-17-induced proliferation, migration, and invasion of gastric cancer cells.

METHODS

IL-17 was used to treat gastric cancer AGS cells, and the cells were divided into Con group, IL-17 group, IL-17 + si-NC group, IL-17 + si-lncRNA NNT-AS1 group, IL-17 + si-lncRNA NNT-AS1 + anti-miR-NC group, and IL-17 + si-lncRNA NNT-AS1 + anti-miR-518a-3p group. Real-time fluorescence quantitative PCR (RT-qPCR) was used to detect miR-518a-3p and NNT-AS1 expression. Colony forming assay and Transwell assay were performed to detect AGS cell proliferation, migration, and invasion. Western blot was used to detect relevant protein expression. Dual luciferase assay was used to detect the relationship of miR-518a-3p and NNT-AS1.

RESULTS

Compared with the Con group, the number of cell colonies, the number of migrating cells, and the number of invasive cells in the IL-17 group increased, the expression of Ki-67, N-cadherin, and MMP2 proteins increased, the expression of E-cadherin protein decreased, the expression of NNT-AS1 increased, and the expression of miR-518a-3p decreased. Down-regulation of NNT-AS1 decreased the number of cell colonies formed, the number of migrating cells, and the number of invasive cells in gastric cancer cells treated with IL-17, decreased the expression of Ki-67, matrix metalloproteinase 2 (MMP2), and N-cadherin proteins, and increased the expression of E-cadherin protein. NNT-AS1 targets and regulates the expression of miR-518a-3p. Inhibition of miR-518a-3p can reverse the effect of down-regulation of NNT-AS1 on IL-17-induced proliferation, migration, and invasion of gastric cancer cells.

CONCLUSION

NNT-AS1 inhibits IL-17-induced gastric cancer cell proliferation, migration, and invasion possibly by regulating the expression of miR-518a-3p.

The role of long non-coding RNAs in the pathogenesis of head and neck squamous cell carcinoma

Head and neck cancers are a heterogeneous collection of malignancies of the upper aerodigestive tract, salivary glands, and thyroid. However, the molecular mechanisms underlying the carcinogenesis of head and neck squamous cell carcinomas (HNSCCs) remain poorly understood. Over the past decades, overwhelming evidence has demonstrated the regulatory roles of long non-coding RNAs (lncRNAs) in tumorigenesis, including HNSCC. Notably, these lncRNAs have vital roles in gene regulation and affect various aspects of cellular homeostasis, including proliferation, survival, and metastasis. They exert regulating functions by interacting with nucleic acids or proteins and affecting cancer cell signaling. LncRNAs represent a burgeoning field of cancer research, and we are only beginning to understand the importance and complicity of lncRNAs in HNSCC. In this review, we summarize the deregulation and function of lncRNAs in human HNSCC. We also review the working mechanism of lncRNAs in HNSCC pathogenesis and discuss the potential application of lncRNAs as diagnostic/prognostic tools and therapeutic targets in human HNSCC.

Impact of Non-Coding RNAs on Chemotherapeutic Resistance in Oral Cancer

Drug resistance in oral cancer is one of the major problems in oral cancer therapy because therapeutic failure directly results in tumor recurrence and eventually in metastasis. Accumulating evidence has demonstrated the involvement of non-coding RNAs (ncRNAs), such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), in processes related to the development of drug resistance. A number of studies have shown that ncRNAs modulate gene expression at the transcriptional or translational level and regulate biological processes, such as epithelial-to-mesenchymal transition, apoptosis, DNA repair and drug efflux, which are tightly associated with drug resistance acquisition in many types of cancer. Interestingly, these ncRNAs are commonly detected in extracellular vesicles (EVs) and are known to be delivered into surrounding cells. This intercellular communication via EVs is currently considered to be important for acquired drug resistance. Here, we review the recent advances in the study of drug resistance in oral cancer by mainly focusing on the function of ncRNAs, since an increasing number of studies have suggested that ncRNAs could be therapeutic targets as well as biomarkers for cancer diagnosis.

Long non-coding RNA HOXA11 antisense RNA upregulates spermatogenesis-associated serine-rich 2-like to enhance cisplatin resistance in laryngeal squamous cell carcinoma by suppressing microRNA-518a

Long noncoding RNAs (LncRNAs) are closely associated with the chemoresistance of laryngeal squamous cell carcinoma (LSCC). Previous studies indicated that HOXA11-AS could function as a vital regulator in human cancers. However, the regulatory mechanisms of HOXA11-AS in the chemoresistance of LSCC remain unclear. In this study, it was found that HOXA11-AS expression was upregulated in cisplatin (CDDP)-resistant LSCC tissues and cells. Loss-of-function assays revealed that HOXA11-AS knockdown inhibited the viability, migration, and invasion, but promoted the apoptosis of CDDP-resistant LSCC cells. Meanwhile, we identified miR-518a as a downstream gene of HOXA11-AS in LSCC, and miR-518a silencing reversed the promotive effect of HOXA11-AS knockdown on CDDP sensitivity of LSCC cells. In addition, miR-518a could inhibit spermatogenesis-associated serine-rich 2-like (SPATS2L) expression by direct interaction, and upregulation of SPATS2L abrogated the inhibitory effect of HOXA11-AS silencing or miR-518a overexpression on CDDP resistance of CDDP-resistant LSCC cells. In sum, our results demonstrated that HOXA11-AS enhanced CDDP resistance of LSCC via miR-518a/SPATS2L axis, which might offer novel therapeutic strategies for CDDP-resistant LSCC.

Urine-derived extracellular vesicle miRNAs as possible biomarkers for and mediators of necrotizing enterocolitis: A proof of concept study

BACKGROUND

Early-stage symptomology of necrotizing enterocolitis (NEC) is similar in presentation to non-NEC sepsis, though the treatment plans differ based on antibiotic administration and withholding of feeds. Improved diagnostics for NEC differentiation would allow clinicians to more rapidly set individual patients on a targeted treatment path. Extracellular vesicle-derived miRNAs, have previously demonstrated efficacy as disease biomarkers. To determine if these miRNAs are differentially-expressed in NEC infants, we performed transcriptomic analysis of urine-derived extracellular vesicle-derived miRNAs.

METHODS

Urine was non-invasively obtained from infants in one of four groups (n ≥ 8) (Medical NEC, Surgical NEC, non-NEC sepsis, and healthy age-matched controls). EV-derived miRNAs were isolated and transcriptomic analysis was performed.

RESULTS

Multiple miRNAs, including miR-376a, miR-518a-3p and miR-604, were significantly altered when comparing NEC to non-NEC sepsis and healthy controls, and could potentially be used as specific NEC biomarkers. Additionally, Ingenuity Pathway Analysis demonstrated that miRs differentially-expressed in NEC were associated with inflammatory disease and intestinal disease. Signal transduction molecules associated with NEC including TP53 and RPS15, which were also reduced transcriptionally in a rat model of NEC.

CONCLUSION

These data indicate that there is a pool of potential urine EV-derived miRNAs that may be validated as NEC biomarkers in the differentiation of NEC from non-NEC sepsis and from age-matched controls. Additionally, signal transduction molecules associated with miRNAs differentially-expressed in human NEC are altered in a murine model of NEC, suggesting potential crossover between murine models of the disease and actual human presentation.

LEVEL OF EVIDENCE

Level III Study of Diagnostic Test.

In silico interaction of HOX cluster-embedded microRNAs and long non-coding RNAs in oral cancer

The essential role HOX-associated non-coding RNAs play in chromatin dynamics and gene regulation has been well documented. The potential roles of these microRNAs and long non-coding RNAs in oral cancer development, with their attendant involvement in various cellular processes including proliferation, invasion, migration, epithelial-mesenchymal transition and metastasis is gaining credence. An interaction network of HOX-embedded non-coding RNAs was constructed to identify the RNA interaction landscape using the arena-Idb platform and visualized using Cytoscape. The miR-10a was shown to interact with HOXA1, miR-10b with HOXD10, miR-196a1 with HOXA5, HOXA7, HOXB8, HOXC8, HOXD8, and miR-196a2 with HOXA5. The lncRNAs, HOTAIR interacted with HOXC11, HOTAIRM1 with HOXA1 and HOXA4, HOTTIP with HOXA13, HOXA-AS2 with HOXA3, HOXA11-AS with HOXA11 and HOXD-AS1 with HOXB8. Changes in the HOX cluster-embedded non-coding RNAs have implications for prognosis and overall disease survival. Our review aims to analyze the functional significance and clinical relevance of non-coding RNAs within the HOX cluster in the context of oral carcinogenesis. Elucidating these interactions between the non-coding RNAs and HOX genes in oral cancer development and progression could pave the way for the identification of reliable biomarkers and potential therapeutic targets.

Integrative profiling analysis identifies the oncogenic long noncoding RNA DUXAP8 in oral cancer

A growing number of studies have revealed the critical roles of long noncoding RNAs (lncRNAs) in the tumorigenesis and cancer progression. Recently, next-generation sequencing technologies combined with bioinformatic have demonstrated that a great number of dysregulated lncRNAs are associated with diverse cancers. However, lots of lncRNAs' function and their underlying molecular mechanisms in oral carcinoma (OC) cancer remain unclear. In this study, we performed integrative lncRNA profiling analysis using the TCGA RNA sequencing data and gene microarray data from Gene Expression Omnibus to identify more OC associated lncRNAs. A total of 619 differentially expressed lncRNAs were identified between the five data sets, and only the double homeobox A pseudogene 8 (DUXAP8) was screened among the up-regulated lncRNAs in all the five groups. Meanwhile, univariate Cox regression analyses disclosed that some lncRNAs are associated with the outcome of OC patients, such as DUXAP8, LINC00152, MIR4435-2HG and LINC00582. Furthermore, we uncovered that silenced DUXAP8 expression exerted suppressive impact on the proliferation of OC cells through interacting with histone-lysine N-methyltransferase enzyme Enhancer of zeste homolog 2 (EZH2) and repressing KLF2 expression. In a word, we identified a lot of unreported OC associated lncRNAs, which may provide a useful resource of lncRNAs for other studies.

MicroRNA in combination with HER2-targeting drugs reduces breast cancer cell viability in vitro

HER2-positive (HER2 +) breast cancer patients that do not respond to targeted treatment have a poor prognosis. The effects of targeted treatment on endogenous microRNA (miRNA) expression levels are unclear. We report that responsive HER2 + breast cancer cell lines had a higher number of miRNAs with altered expression after treatment with trastuzumab and lapatinib compared to poorly responsive cell lines. To evaluate whether miRNAs can sensitize HER2 + cells to treatment, we performed a high-throughput screen of 1626 miRNA mimics and inhibitors in combination with trastuzumab and lapatinib in HER2 + breast cancer cells. We identified eight miRNA mimics sensitizing cells to targeted treatment, miR-101-5p, mir-518a-5p, miR-19b-2-5p, miR-1237-3p, miR-29a-3p, miR-29c-3p, miR-106a-5p, and miR-744-3p. A higher expression of miR-101-5p predicted better prognosis in patients with HER2 + breast cancer (OS: p = 0.039; BCSS: p = 0.012), supporting the tumor-suppressing role of this miRNA. In conclusion, we have identified miRNAs that sensitize HER2 + breast cancer cells to targeted therapy. This indicates the potential of combining targeted drugs with miRNAs to improve current treatments for HER2 + breast cancers.

Long Non-Coding RNAs as Functional Codes for Oral Cancer: Translational Potential, Progress and Promises

Oral cancer is one of the leading malignant tumors worldwide. Despite the advent of multidisciplinary approaches, the overall prognosis of patients with oral cancer is poor, mainly due to late diagnosis. There is an urgent need to develop valid biomarkers for early detection and effective therapies. Long non-coding RNAs (lncRNAs) are recognized as key elements of gene regulation, with pivotal roles in various physiological and pathological processes, including cancer. Over the past few years, an exponentially growing number of lncRNAs have been identified and linked to tumorigenesis and prognosis outcomes in oral cancer, illustrating their emerging roles in oral cancer progression and the associated signaling pathways. Herein, we aim to summarize the most recent advances made concerning oral cancer-associated lncRNA, and their expression, involvement, and potential clinical impact, reported to date, with a specific focus on the lncRNA-mediated molecular regulation in oncogenic signaling cascades and oral malignant progression, while exploring their potential, and challenges, for clinical applications as biomarkers or therapeutic targets for oral cancer.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Long Non-Coding RNA HOXA11-AS Modulates Proliferation, Apoptosis, Metastasis and EMT in Cutaneous Melanoma Cells Partly via miR-152-3p/ITGA9 Axis

Background

Long non-coding RNA homeobox A11 antisense RNA (HOXA11-AS) was showed to participate in the progression of different kinds of tumors, but the specific role of HOXA11-AS in cutaneous melanoma is not entirely unambiguous.

Methods

The levels of HOXA11-AS, microRNA-152-3p (miR-152-3p) and integrin alpha9 (ITGA9) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was detected via 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT), and apoptosis was measured by flow cytometry. The assessment of cell metastasis was performed by transwell migration and invasion assays. The protein levels were detected through Western blot. Dual-luciferase reporter assay was utilized to explore the target relationship among HOXA11-AS, miR-152-3p and ITGA9. The effect of HOXA11-AS on melanoma in vivo was investigated via xenograft experiment.

Results

HOXA11-AS and ITGA9 were up-regulated while miR-152-3p was down-regulated in melanoma. Knockdown of HOXA11-AS refrained cell proliferation, metastasis and epithelial-mesenchymal transition (EMT) but induced apoptosis in melanoma cells. HOXA11-AS targeted miR-152-3p and overexpression of HOXA11-AS mitigated the miR-152-3p-induced effects on melanoma cellular behaviors. ITGA9 was a target of miR-152-3p and miR-152-3p inhibitor relieved the repression on proliferation, metastasis and EMT while elevation on apoptosis caused by si-ITGA9 via elevating ITGA9. HOXA11-AS knockdown restrained ITGA9 expression via up-regulating miR-152-3p. Suppression of HOXA11-AS inhibited melanoma progression in part through increasing miR-152-3p and decreasing ITGA9 expression in vivo.

Conclusion

HOXA11-AS modulated proliferation, apoptosis, metastasis and EMT in melanoma cells by regulating miR-152-3p/ITGA9 axis in part. HOXA11-AS could promote melanoma development and be used as a promising biomarker in the diagnosis and treatment for cutaneous melanoma.

lncRNA SNHG5 promotes cell proliferation, migration and invasion in oral squamous cell carcinoma by sponging miR-655-3p/FZD4 axis

Recently, previous studies have shown that long non-coding RNA (lncRNA) can act as a tumor promoter or inhibitor in the pathogenesis of oral squamous cell carcinoma (OSCC). However, the regulatory mechanism of lncRNA SNHG5 is unknown in OSCC. Therefore, the functional mechanism of lncRNA SNHG5 in OSCC was initially revealed in this study. Here, RT-qPCR and western blot analysis were used to assess mRNA and protein expression. The functional mechanism of SNHG5 was investigated by MTT, Transwell and luciferase reporter assays. The results showed that SNHG5 expression was upregulated in OSCC and promoted the viability, migration and invasion of OSCC cells. In addition, SNHG5 is the sponge of miR-655-3p in OSCC. And miR-655-3p was found to play an inhibitory effect in OSCC by interacting with SNHG5. Moreover, miR-655-3p directly targets FZD4 and negatively regulates its expression in OSCC. Functionally, FZD4 promoted the progression of OSCC by interacting with the SNHG5/miR-655-3p axis. In conclusion, lncRNA SNHG5 promotes cell proliferation, migration and invasion in OSCC by regulating miR-655-3p/FZD4 axis.

Long noncoding RNAs in head and neck squamous cell carcinoma: biological functions and mechanisms

Head and neck squamous cell carcinoma (HNSCC) is the primary malignant tumor of the oral cavity, larynx, nasopharynx, esophagus and tongue. Although several novel therapeutic methods for HNSCC have been developed, the final therapeutic effect on the patient is still not satisfactory. Thus, it is imperative that scientists identify novel distinguishable markers with specific molecular characteristics that can be used in therapeutic and prognostic evaluation. Previous reports have shown that long noncoding RNAs (lncRNAs) are important regulators of gene expression in many cancers, including head and neck squamous cell carcinomas. Translational studies of lncRNAs in HNSCC are urgently required before their application as a treatment can be realized. We aimed to address the most relevant findings on lncRNAs as biomarkers or treatment targets in head and neck squamous cell carcinoma and to summarize their discovered pathways and mechanisms of action to reveal the possible future applications of these novel biomarkers in clinical translational research.

The long non-coding RNA HOXA11-AS promotes epithelial mesenchymal transition by sponging miR-149-3p in Colorectal Cancer

Background: Metastasis is the primary cause of death in colorectal cancer (CRC); the underlying mechanisms remain partly unknown. In this study, we aim to investigate the value of HOXA11-AS in survival evaluation and the potential role of HOXA11-AS/miR-149-3p axis in the CRC metastasis.

Methods: The expressions of HOXA11-AS, both in obtained CRC samples and adjacent noncancerous tissues, were analyzed in survival evaluation. Competing endogenous RNAs (CeRNAs) Analysis were employed to reveal the potential relationship between HOXA11-AS and miR-149-3p. It was further confirmed by Quantitative real-time polymerase chain reaction (qRT-PCR) and Dual-luciferase reporter assay. Migration and invasion assay were used to verify the potential role of HOXA11-AS and miR-149-3p in the regulation of CRC metastasis. The potential pathway was explored by Western blot analysis.

Results: The expression of HOXA11-AS in the CRC tissue is significantly higher than the expression in adjacent noncancerous tissue (p<0.0001). High expressions of HOXA11-AS were noticeably correlated with clinicopathologic characteristics including advanced clinical stage (p=0.021), larger tumor size (p<0.001) and frequent tumor recurrence (p=0.001). The overall survival in HOXA11-AS-High group was significantly shorter than the HOXA11-AS-Low group (p<0.001). Advanced clinical stage, tumor size and high expression of HOXA11-AS were showed as independent prognostic prediction factors for the 5-year tumor relapse of CRC patients (p<0.001). HOXA11-AS acts as a potential molecular sponge for miR-149-3p, in the promotion of CRC metastasis. In the miR-149-3p mimic-treated group, the expression of E-cadherin was increased, whereas the expression of N-cadherin, Snail, Slug, TGF-β1, Wnt2b, Twist and C/EBPβ was decreased.

Conclusion: This study demonstrates that high expression of HOXA11-AS is correlated with CRC progression and poor prognosis and may promote metastasis via EMT by modulating miR-149-3p.

ZFAS1 Promotes Cisplatin Resistance via Suppressing miR-421 Expression in Oral Squamous Cell Carcinoma

Purpose

Oral squamous cell carcinoma (OSCC), with high incidence and mortality, represents one of the main reasons for head and neck malignant tumors. We want to investigate the effect of ZFAS1 on DDP resistance in oral squamous cell carcinoma.

Methods

The proliferation and migration of cells was detected by CCK-8 and Transwell assay. The apoptosis was measured by flow cytometry and Western blot. The interaction of ZFAS1, miR-421, and MEIS2 was verified by luciferase reporter assay. The role of ZFAS1 in DDP resistance in vivo was tested by the nude mice model. The expression of ZFAS1 in exosomes from cisplatin-resistant patients was also determined.

Results

ZFAS1 overexpression improved OSCC cell growth and inhibited OSCC cell susceptibility to DDP. In addition, the silencing of ZFAS1 promoted DDP-induced apoptosis. ZFAS1 directly bound to miR-421, which was verified by luciferase reporter assay. Inhibition of miR-421 reversed the effect of si-ZFAS1, which promoted the cell viability and decreased the sensitivity of DDP in DDP-resistant cells. The in vivo experiment showed the role of ZFAS1 in increasing the DDP resistance in OSCC tumor. Importantly, this study also showed upregulated ZFAS1 in serum exosomes derived from cisplatin-resistant patients.

Conclusion

ZFAS1 promotes chemoresistance of oral squamous cell carcinoma to cisplatin and might become a latent therapeutic target for treating OSCC.

LncRNA MCM3AP-AS1 promotes proliferation, migration and invasion of oral squamous cell carcinoma cells via regulating miR-204-5p/FOXC1

Oral squamous cell carcinoma (OSCC) is a lethal malignancy. It is reportedly demonstrated that long non-coding RNA (lncRNA) participates in the development of OSCC. The purpose of this study was to clarify the function and possible molecular mechanisms of lncRNA MCM3AP antisense RNA 1 (lncRNA MCM3AP-AS1) in OSCC. Quantitative real-time PCR (qRT-PCR) was adopted to investigate MCM3AP-AS1 expressions in OSCC tissues and cells. The proliferation, migration and invasion of HN-6 and SCC-9 cells were probed by cell counting kit-8 and Transwell assays, respectively. Dual luciferase reporter gene assay, Pearson's correlation analysis, qRT-PCR and western blot were used to detect the binding relationship among miR-204-5 p, MCM3AP-AS1 and forkheadbox C1 (FOXC1). MCM3AP-AS1 expression was elevated in OSCC tissues and cell lines. Overexpression of MCM3AP-AS1 facilitated the proliferation, migration and invasion of OSCC cells, while the knockdown of MCM3AP-AS1 suppressed these malignant phenotypes. Besides, MCM3AP-AS1 impeded miR-204-5 p by binding with it. MCM3AP-AS1 could also upregulate the expression of FOXC1 via repressing miR-204-5 p.MCM3AP-AS1 promotes the progression of OSCC cells by adsorbing miR-204-5 p and upregulating FOXC1 expressions.

FOXA1-induced LINC01207 facilitates head and neck squamous cell carcinoma via up-regulation of TNRC6B

Head and neck squamous cell carcinoma (HNSCC) is a common cancer in China, which was mainly caused by smoking and HPV infection. With the advancement of molecular research, it is meaningful to explore the biomarkers of HNSCC. LINC01207 (small integral membrane protein 31, also known as SMIM31) is a verified oncogene in colorectal adenocarcinoma. Present study aimed to explore the function of LINC01207 in HNSCC cells. Function assays including EdU, colony formation, TUNEL and JC-1 assay revealed that LINC01207 was an oncogene in HNSCC cells. Next, by some mechanism assays including RIP assay and luciferase reporter assay, miR-5047 was identified as the downstream gene of LINC01207. Subsequently, trinucleotide repeat containing adaptor 6B (TNRC6B) was verified as the target of miR-5047. LINC01207 boosted HNSCC cell proliferation and stemness characteristics via acting as a ceRNA of TNRC6B to bind miR-5047. Then, we identified that transcription of both LINC01207 and TNRC6B was induced by FOXA1, which played a tumor facilitator role in HNSCC cells. In a word, present study uncovered a novel ceRNA mechanism of LINC01207/miR-5047/TNRC6B in HNSCC cells, which might contribute to HNSCC treatment.

LncRNA SNHG7 promotes the proliferation of nasopharyngeal carcinoma by miR-514a-5p/ELAVL1 axis

Background

Nasopharyngeal carcinoma (NPC), with distinct geographical distribution, has gathered public attention. Despite that radiotherapy and chemotherapy are applied to treat NPC, cell metastasis still cannot be avoided. Numerous works have elucidated that lncRNAs are essential players in the development of multiple cancers. LncRNA SNHG7 has been reported as a contributing factor in the occurrence of certain cancers, but its mechanism in NPC deserves further investigation. The purpose of the study is to figure out the role and molecular regulation mechanism of SNHG7 in NPC.

Methods

The role of SNHG7 in NPC was verified by CCK-8, colony formation, EdU staining, western blot and capase-3 assays. The interactions between SNHG7/ELAVL1 and miR-514a-5p were confirmed by RNA pull down, RT-qPCR, RIP and luciferase reporter assays.

Results

SNHG7 was upregulated in NPC cells, and absence of SNHG7 suppressed cell proliferation as well as promoted cell apoptosis in NPC. Furthermore, SNHG7 was confirmed to bind with miR-514a-5p and negatively modulate miR-514a-5p expression. Besides, miR-514a-5p was found to be able to bind with ELAVL1 and negatively regulate ELAVL1 mRNA and protein expressions. In the end, rescue assays demonstrated that the miR-514a-5p deficiency restored the NPC progression inhibited by SNHG7 silence, and ELAVL1 partly counteracted the restoration caused by miR-514a-5p inhibitor in HNE1 cells.

Conclusions

LncRNA SNHG7 promotes the proliferation and migration of nasopharyngeal carcinoma by miR-514a-5p/ ELAVL1 axis.

Long noncoding RNA UCA1 promotes cell growth, migration, and invasion by targeting miR-143-3p in oral squamous cell carcinoma

BACKGROUND

The long noncoding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) is dysregulated in many types of tumors; however, its role in oral squamous cell carcinoma (OSCC) remains unclear. This study aims to determine the effect of lncRNA UCA1 on OSCC.

METHODS

Fifty-six paired OSCC and adjacent nontumorous tissues were collected and the levels of UCA1, miR-143-3p, and MYO6 in the tissues were evaluated by qRT-PCR. In in vitro experiments, cell viability, migration, and invasion were measured by, respectively, performing CCK-8, wound healing, and transwell assays. The target relationships among UCA1, miR-143-3p, and MYO6 were verified by dual-luciferase assay. Western blot and immunohistochemistry were carried out to determine the protein levels. Xenograft mouse model was established to explore the effects of UCA1 in vivo.

RESULTS

Levels of UCA1 and MYO6 were increased significantly in OSCC, while the level of miR-143-3p was decreased compared with the adjacent nontumorous tissues. UCA1 promoted OSCC cell growth, migration, and invasion both in vitro and in vivo, while miR-143-3p reversed the progression. MYO6 was validated as a target for miR-143-3p, and MYO6 overexpression reversed the effects of miR-143-3p mimic on OSCC cells.

CONCLUSION

LncRNA UCA1 contributes to the proliferation and metastasis of OSCC cells by targeting miR-143-3p and upregulating its downstream gene MYO6. UCA1 could serve as a promising novel target therapy for treatment of OSCC.

LINC00467 enhances head and neck squamous cell carcinoma progression and the epithelial-mesenchymal transition process via miR-299-5p/ubiquitin specific protease-48 axis

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) has attracted the attention of researchers as a result of its high incidence around the world. This malignancy occurs in the oral cavity, pharynx and larynx in most cases. A number of lncRNAs have been revealed to regulate the malignant neoplasia of several cancers. Nevertheless, the effects of lncRNA LINC00467 in HNSCC have not yet been reported.

METHODS

The expression of LINC00467, miR-299-5p and ubiquitin specific protease-48 (USP48) in HNSCC cells was quantified by a quantitative reverse transcriptase-polymerase chain reaction. The influences of LINC00467 deficiency on HNSCC progression were reflected by cell counting kit-8, colony formation, ethynyl-2-deoxyuridine, wound healing and western blot assays. RIP and luciferase reporter assays were conducted to confirm the interaction among LINC00467, miR-299-5p and USP48.

RESULTS

LINC00467 was considerably upregulated in HNSCC cells, and an absence of LINC00467 suppressed cell growth, cell migration and the epithelial-mesenchymal process in HNSCC. In addition, miR-299-5p expression was notably downregulated in HNSCC cells, and miR-299-5p could bind with LINC00467. Furthermore, USP48 was conspicuously overexpressed in HNSCC cells and capable of binding with miR-299-5p. LINC00467 could upregulate USP48 expression via sponging miR-299-5p. Finally, rescue assays proved that USP48 overexpression could compensate for the suppressive effects on HNSCC progression mediated by LINC00467 deficiency.

CONCLUSIONS

LINC00467 enhances HNSCC progression by serving as a sponge of miR-299-5p to increase USP48 expression.

LncRNA HOXA11-AS promotes OSCC progression by sponging miR-98-5p to upregulate YBX2 expression

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a type of oral malignancy. Long non-coding RNAs (lncRNAs) have been shown to be related to the occurrence and development of many cancers. Here, we aimed to study the role and molecular mechanism of lncRNA Homeobox A11 antisense RNA (HOXA11-AS) in OSCC.

METHODS

The expression levels of HOXA11-AS, miR-98-5p and Y box binding protein 2 (YBX2) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8), flow cytometry and transwell assays were utilized to determine the proliferation, apoptosis, migration and invasion of OSCC cells. Western blot (WB) analysis was conducted to measure the levels of apoptosis, epithelial-mesenchymal transition (EMT), proliferation-related proteins and YBX2 protein. Besides, Dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull down assays were carried out to examine the relationship among HOXA11-AS, miR-98-5p and YBX2. The mice xenograft models were constructed to further determine the effect of HOXA11-AS on OSCC tumor growth in vivo.

RESULTS

HOXA11-AS was highly expressed in OSCC tissues and cells. Knockdown of HOXA11-AS significantly reduced proliferation, migration, invasion and EMT, while promoted apoptosis of OSCC cells. MiR-98-5p was a target of HOXA11-AS, and its inhibitor could revert the inhibition effect of silenced-HOXA11-AS on the progression of OSCC. Also, YBX2 was a target of miR-98-5p, and its overexpression could invert the suppression effect of miR-98-5p overexpression on the progression of OSCC. YBX2 expression was regulated by HOXA11-AS and miR-98-5p. Furthermore, HOXA11-AS silencing could reduce the tumor growth of OSCC in vivo.

CONCLUSION

HOXA11-AS plays an active role in the progression of OSCC, and the discovery of HOXA11-AS/miR-98-5p/YBX2 axis provides new therapeutic targets for OSCC.

Epigenetic Modifications in Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common human malignancy in the world, with high mortality and poor prognosis for patients. Among the risk factors are tobacco and alcohol intake, human papilloma virus, and also genetic and epigenetic modifications. Many studies show that epigenetic events play an important role in HNSCC development and progression, including DNA methylation, chromatin remodeling, histone posttranslational covalent modifications, and effects of non-coding RNA. Epigenetic modifications may influence silencing of tumor suppressor genes by promoter hypermethylation, regulate transcription by microRNAs and changes in chromatin structure, or induce genome instability through hypomethylation. Moreover, getting to better understand aberrant patterns of methylation may provide biomarkers for early detection and diagnosis, while knowledge about target genes of microRNAs may improve the therapy of HNSCC and extend overall survival. The aim of this review is to present recent studies which demonstrate the role of epigenetic regulation in the development of HNSCC.