LncRNA XIST promotes the progression of laryngeal squamous cell carcinoma via sponging miR-125b-5p to modulate TRIB2

SOCS1 as a Biomarker Candidate for HPV Infection and Prognosis of Head and Neck Squamous Cell Carcinomas

The pathogenesis of head and neck squamous cell carcinoma (HNSCC) is associated with human papillomavirus (HPV) infection. However, the molecular mechanisms underlying the interactions between HNSCC and HPV remain unclear. Bioinformatics was used to analyze the gene expression dataset of HPV-associated HNSCC based on the Cancer Genome Atlas (TCGA) database. Differentially expressed genes (DEGs) in HPV-positive and HPV-negative HNSCC were screened. Gene function enrichment, protein-protein interactions (PPI), survival analysis, and immune cell infiltration of DEGs were performed. Furthermore, the clinical data of HNSCC tissue samples were analyzed using immunohistochemistry. In total, 194 DEGs were identified. A PPI network was constructed and 10 hub genes (EREG, PLCG1, ERBB4, HBEGF, ZFP42, CBX6, NFKBIA, SOCS1, ATP2B2, and CEND1) were identified. Survival analysis indicated that low expression of SOCS1 was associated with worse overall survival. Immunohistochemistry demonstrated that SOCS1 expression was higher in HPV-negative HNSCC than in HPV-positive HNSCC, and there was a positive correlation between SOCS1 expression and patient survival. This study provides new information on biological targets that may be relevant to the molecular mechanisms underpinning the occurrence and development of HNSCC. SOCS1 may play an important role in the interaction between HPV and HNSCC and serve as a potential biomarker for future therapeutic targets.

Potential roles of lncRNA-XIST/miRNAs/mRNAs in human cancer cells

Long non-coding RNAs (lncRNAs) are non-coding RNAs that contain more than 200 nucleotides but do not code for proteins. In tumorigenesis, lncRNAs can have both oncogenic and tumor-suppressive properties. X inactive-specific transcript (XIST) is a known lncRNA that has been implicated in X chromosome silencing in female cells. Dysregulation of XIST is associated with an increased risk of various cancers. Therefore, XIST can be a beneficial prognostic biomarker for human malignancies. In this review, we attempt to summarize the emerging roles of XIST in human cancers.

Pan-cancer analysis of LncRNA XIST and its potential mechanisms in human cancers

Background

Methods

Results

Conclusion

Downregulation of long noncoding RNA HCP5/miR-216a-5p/ZEB1 axis inhibits the malignant biological function of laryngeal squamous cell carcinoma cells

Previous studies find that long noncoding RNA human leukocyte antigen complex P5 (HCP5) is regarded as an oncogene via accelerating cancer cell growth, invasion, metastasis, vascularization, and drug resistance in renal cell carcinoma, gastric cancer, and colorectal cancer. Nevertheless, the effect and regulatory mechanism of HCP5 in laryngeal squamous cell carcinoma (LSCC) remains unknown. In this study, HCP5 expression levels were confirmed to be prominently raised in LSCC cell lines. HCP5 knockdown reduced cell proliferation and migration and invasive ability of LSCC cell lines. Furthermore, miR-216a-5p was confirmed to sponge HCP5, and its expression was prominently downregulated in LSCC cell lines and upregulated in HCP5-silenced LSCC cell lines. miR-216a-5p overexpression downregulated the cell proliferation and migration and invasive ability of LSCC cells. Additionally, the protein level of zinc finger E-box binding homeobox 1 (ZEB1), one target gene of miR-216a-5p, was highly expressed in LSCC cell lines, and its expression level was downregulated by HCP5 knockdown and miR-216a-5p overexpression. An miR-216a-5p inhibitor reversed the effect of HCP5 knockdown on the proliferation and migration and invasive ability of LSCC cells. In conclusion, knocking down HCP5 may be a strategy to suppress the malignant biological function via regulating miR-216a-5p/ZEB1. Therefore, HCP5 may become a prospective therapeutic target for LSCC.

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.

The lncRNAs at X Chromosome Inactivation Center: Not Just a Matter of Sex Dosage Compensation

Non-coding RNAs (ncRNAs) constitute the majority of the transcriptome, as the result of pervasive transcription of the mammalian genome. Different RNA species, such as lncRNAs, miRNAs, circRNA, mRNAs, engage in regulatory networks based on their reciprocal interactions, often in a competitive manner, in a way denominated “competing endogenous RNA (ceRNA) networks” (“ceRNET”): miRNAs and other ncRNAs modulate each other, since miRNAs can regulate the expression of lncRNAs, which in turn regulate miRNAs, titrating their availability and thus competing with the binding to other RNA targets. The unbalancing of any network component can derail the entire regulatory circuit acting as a driving force for human diseases, thus assigning “new” functions to “old” molecules. This is the case of XIST, the lncRNA characterized in the early 1990s and well known as the essential molecule for X chromosome inactivation in mammalian females, thus preventing an imbalance of X-linked gene expression between females and males. Currently, literature concerning XIST biology is becoming dominated by miRNA associations and they are also gaining prominence for other lncRNAs produced by the X-inactivation center. This review discusses the available literature to explore possible novel functions related to ceRNA activity of lncRNAs produced by the X-inactivation center, beyond their role in dosage compensation, with prospective implications for emerging gender-biased functions and pathological mechanisms.

Long non-coding RNA XIST: a novel oncogene in multiple cancers

Long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is an important lncRNA derived from the XIST gene in mammals. XIST is abnormally expressed in numerous tumors, in most of which XIST functions as an oncogene. XIST is involved in multiple aspects of carcinogenesis, including tumor onset, progression, and prognosis. In our review, we collected and analyzed the recent studies on the impact of XIST in human tumor development. The multilevel molecular functions of XIST in human tumors are comprehensively reviewed to clarify the pathologic mechanisms and to offer a novel direction for further study.

LncRNA SNHG16 promotes proliferation and migration in laryngeal squamous cell carcinoma via the miR-140-5p/NFAT5/Wnt/β-catenin pathway axis

BACKGROUND

Recent studies demonstrate that long noncoding RNAs (lncRNAs) are involved in the development of various cancers. Many lncRNAs were reported to abnormally express in laryngeal squamous cell carcinoma (LSCC) and play pivotal roles in its development. LncRNA small nucleolar RNA host gene 16 (SNHG16) was previously validated as an oncogene in hepatocellular carcinoma. Nevertheless, the biological role of SNHG16 in LSCC still needs more explorations. The goal of this assay is to explore the function and molecular mechanism of lncRNA SNHG16 in the development of LSCC.

METHODS AND RESULTS

First, RT-qPCR demonstrated the upregulation of SNHG16 in LSCC cells and tissues. Loss-of-function assays determined the inhibitive influence of SNHG16 downregulation on cell viability, growth, and migration in LSCC. Furthermore, SNHG16 bound with miR-140-5p in LSCC. MiR-140-5p overexpression suppressed LSCC cell proliferation and migration. NFAT5 was identified as a direct target of miR-140-5p. Through rescue experiments, overexpression of NFAT5 reversed SNHG16 knockdown-mediated suppression on cell viability, growth, and migration in LSCC. Additionally, NFAT5 overexpression activated while NFAT5 downregulation inhibited the Wnt/β-catenin signaling pathway.

CONCLUSION

LncRNA SNHG16 is upregulated in LSCC and contributes to the development of LSCC via regulating the miR-140-5p/NFAT5/Wnt/β-catenin pathway axis. The SNHG16/miR-140-5p/NFAT5/Wnt/β-catenin pathway axis might provide a novel strategy for LSCC treatment.

LINC01087 indicates a poor prognosis of glioma patients with preoperative MRI

Long intergenic non-coding RNA 01,087 (LINC01087) has been concerned as an oncogene in breast cancer, while its mechanism in glioma has been little surveyed. Thus, we searched the prognostic value and functional action of LINC01087 in glioma. Glioma patients after preoperative MRI diagnosis were enrolled, and LINC01087, microRNA (miR)-1277-5p, and alkaline ceramidase 3 (ACER3) levels were tested in glioma cancer tissue. The correlation between LINC01087 expression and the survival of patients were analyzed. LINC01087, miR-1277-5p, and ACER3 levels in U251 cells were altered via transfection, and cell malignant phenotypes were monitored. The relationship between miR-1277-5p and LINC01087 or ACER3 was detected. The LINC01087 and ACER3 expression was in up-regulation and the miR-1277-5p expression was in down-regulation in clinical glioma samples. High expression of LINC01087 was associated with poor prognosis of glioma patients with preoperative MRI. LINC01087 silencing restrained tumor malignancy in glioma cells. Mechanistically, LINC01087 directly interacted with miR-1277-5p. ACER3 was a known target of miR-1277-5p. Moreover, rescue assays reveal that miR-1277-5p overexpression (or ACER3 overexpression) reversed the effects of LINC01087 upregulation (or miR-1277-5p upregulation) on glioma cells. LINC01087 has prognostic significance in glioma and silencing LINC01087 deters glioma development through elevating miR-1277-5p to reduce ACER3 expression.

FOXP4 promotes laryngeal squamous cell carcinoma progression through directly targeting LEF‑1

Forkhead box (FOX) proteins are multifaceted transcription factors that have been shown to be involved in cell cycle progression, proliferation and metastasis. FOXP4, a member of the FOX family, has been implicated in diverse biological processes in tumor initiation and progression. However, the molecular mechanisms of FOXP4 in laryngeal squamous cell carcinoma (LSCC) remain unknown. In the present study, differentially expressed transcripts in transforming growth factor‑β‑treated TU177 cells were screened using microarrays and it was found that FOXP4 was significantly upregulated. The high expression of FOXP4 was detected in LSCC tissues and cells, and predicted poor prognosis. The role of FOXP4 in laryngeal cancer cell proliferation, migration and invasion was determined by gain‑ and loss‑of‑function assays. Besides, FOXP4 was demonstrated to participate in the epithelial‑mesenchymal transition process at the mRNA and protein levels. Mechanically, FOXP4 directly bound to the promoter of lymphoid enhancer‑binding factor 1 and activated Wnt signaling pathway, which was confirmed via chromatin immunoprecipitation and luciferase reporter assays. Consequently, these findings provided novel mechanisms of FOXP4 in LSCC progression, which may be considered as potential therapeutic and prognostic targets for LSCC.

X-Inactive-Specific Transcript: Review of Its Functions in the Carcinogenesis

X-inactive-specific transcript (XIST) is one of the firstly discovered long non-coding RNAs with prominent roles in the process of X inactivation. Moreover, this transcript contributes in the carcinogenic process in different tissues. In addition to interacting with chromatin modifying molecules, XIST can be served as a molecular sponge for miRNAs to modulate expression of miRNA targets. Most of the studies have indicated an oncogenic role for XIST. However, in prostate cancer, a single study has indicated a tumor suppressor role for this lncRNA. Similar result has been reported for XIST in oral squamous cell carcinoma. In hepatocellular carcinoma, breast cancer, ovarian cancer, osteosarcoma, and renal cell carcinoma, different studies have reported inconsistent results. In the present manuscript, we review function of XIST in the carcinogenesis.

Biological Function of Long Non-coding RNA (LncRNA) Xist

Long non-coding RNAs (lncRNAs) regulate gene expression in a variety of ways at epigenetic, chromatin remodeling, transcriptional, and translational levels. Accumulating evidence suggests that lncRNA X-inactive specific transcript (lncRNA Xist) serves as an important regulator of cell growth and development. Despites its original roles in X-chromosome dosage compensation, lncRNA Xist also participates in the development of tumor and other human diseases by functioning as a competing endogenous RNA (ceRNA). In this review, we comprehensively summarized recent progress in understanding the cellular functions of lncRNA Xist in mammalian cells and discussed current knowledge regarding the ceRNA network of lncRNA Xist in various diseases. Long non-coding RNAs (lncRNAs) are transcripts that are more than 200 nt in length and without an apparent protein-coding capacity (Furlan and Rougeulle, 2016; Maduro et al., 2016). These RNAs are believed to be transcribed by the approximately 98-99% non-coding regions of the human genome (Derrien et al., 2012; Fu, 2014; Montalbano et al., 2017; Slack and Chinnaiyan, 2019), as well as a large variety of genomic regions, such as exonic, tronic, and intergenic regions. Hence, lncRNAs are also divided into eight categories: Intergenic lncRNAs, Intronic lncRNAs, Enhancer lncRNAs, Promoter lncRNAs, Natural antisense/sense lncRNAs, Small nucleolar RNA-ended lncRNAs (sno-lncRNAs), Bidirectional lncRNAs, and non-poly(A) lncRNAs (Ma et al., 2013; Devaux et al., 2015; St Laurent et al., 2015; Chen, 2016; Quinn and Chang, 2016; Richard and Eichhorn, 2018; Connerty et al., 2020). A range of evidence has suggested that lncRNAs function as key regulators in crucial cellular functions, including proliferation, differentiation, apoptosis, migration, and invasion, by regulating the expression level of target genes via epigenomic, transcriptional, or post-transcriptional approaches (Cao et al., 2018). Moreover, lncRNAs detected in body fluids were also believed to serve as potential biomarkers for the diagnosis, prognosis, and monitoring of disease progression, and act as novel and potential drug targets for therapeutic exploitation in human disease (Jiang W. et al., 2018; Zhou et al., 2019a). Long non-coding RNA X-inactive specific transcript (lncRNA Xist) are a set of 15,000-20,000 nt sequences localized in the X chromosome inactivation center (XIC) of chromosome Xq13.2 (Brown et al., 1992; Debrand et al., 1998; Kay, 1998; Lee et al., 2013; da Rocha and Heard, 2017; Yang Z. et al., 2018; Brockdorff, 2019). Previous studies have indicated that lncRNA Xist regulate X chromosome inactivation (XCI), resulting in the inheritable silencing of one of the X-chromosomes during female cell development. Also, it serves a vital regulatory function in the whole spectrum of human disease (notably cancer) and can be used as a novel diagnostic and prognostic biomarker and as a potential therapeutic target for human disease in the clinic (Liu et al., 2018b; Deng et al., 2019; Dinescu et al., 2019; Mutzel and Schulz, 2020; Patrat et al., 2020; Wang et al., 2020a). In particular, lncRNA Xist have been demonstrated to be involved in the development of multiple types of tumors including brain tumor, Leukemia, lung cancer, breast cancer, and liver cancer, with the prominent examples outlined in Table 1. It was also believed that lncRNA Xist (Chaligne and Heard, 2014; Yang Z. et al., 2018) contributed to other diseases, such as pulmonary fibrosis, inflammation, neuropathic pain, cardiomyocyte hypertrophy, and osteoarthritis chondrocytes, and more specific details can be found in Table 2. This review summarizes the current knowledge on the regulatory mechanisms of lncRNA Xist on both chromosome dosage compensation and pathogenesis (especially cancer) processes, with a focus on the regulatory network of lncRNA Xist in human disease.

LncRNA MNX1-AS1 Contributes to Laryngeal Squamous Cell Carcinoma Growth and Migration by Regulating mir-744-5p/bcl9/β-Catenin Axis

Increasing evidence has indicated that long noncoding RNAs (lncRNAs) are involved in the progression of laryngeal squamous cell carcinoma (LSCC). Here, we aimed to disclose the role of MNX1-AS1 in LSCC progression, and explore whether MNX1-AS1 participates in LSCC progression via targeting miR-744-5p to active BCL9/β-catenin signaling. Sixty-five human LSCC tissues and the paracancerous normal tissues were recruited to determine the levels of MNX1-AS1, miR-744-5p and BCL9 using qRT-PCR. The interaction of miR-744-5p and MNX1-AS1/BCL9 was determined by using the RNA immunoprecipitation (RIP) assay and/or luciferase gene reporter assay. Cell viability, in vivo tumor formation, invasion and migration abilities were detected by MTT, Xenograft models and Transwell assays. MNX1-AS1 level was increased significantly in human LSCC tissues as compared with the normal tissues, which showed a positive correlation with BCL9 level while a negative correlation with miR-744-5p level. High level of MNX1-AS1 predicted a poor prognosis and an advanced clinical process in LSCC patients. miR-744-5p targeted upregulation weakened the luciferase activity of MNX1-AS1 and /BCL9, and downregulated their expression levels-wt, while showed no effect when the binding sites were mutated. Knockdown of MNX1-AS1 markedly weakened cell viability, migration, and invasion abilities, while BCL9 overexpression abolished these tendencies. In addition, MNX1-AS1 downregulation induced decreases in tumor volumes and weights in vivo, accompanied by reductions in BCL9, Ki-67 and β-catenin expression and an increase in miR-744-5p expression. Collectively, this study reveals that MNX1-AS1 contributes to cell growth and migration by regulating miR-744-5p/BCL9/β-catenin axis in LSCC.

Tribbles homolog 2 (Trib2), a pseudo serine/threonine kinase in tumorigenesis and stem cell fate decisions

The family of Tribbles proteins play many critical nonenzymatic roles and regulate a wide range of key signaling pathways. Tribbles homolog 2 (Trib2) is a pseudo serine/threonine kinase that functions as a scaffold or adaptor in various physiological and pathological processes. Trib2 can interact with E3 ubiquitin ligases and control protein stability of downstream effectors. This protein is induced by mitogens and enhances the propagation of several cancer cells, including myeloid leukemia, liver, lung, skin, bone, brain, and pancreatic. Thus, Trib2 can be a predictive and valuable biomarker for the diagnosis and treatment of cancer. Recent studies have illustrated that Trib2 plays a major role in cell fate determination of stem cells. Stem cells have the capacity to self-renew and differentiate into specific cell types. Stem cells are important sources for cell-based regenerative medicine and drug screening. Trib2 has been found to increase the self-renewal ability of embryonic stem cells, the reprogramming efficiency of somatic cells, and chondrogenesis. In this review, we will focus on the recent advances of Trib2 function in tumorigenesis and stem cell fate decisions.

Control of Cell Growth and Proliferation by the Tribbles Pseudokinase: Lessons from Drosophila

Simple Summary

Tribbles pseudokinases represent a sub-branch of the CAMK (Ca²⁺/calmodulin-dependent protein kinase) subfamily and are associated with disease-associated signaling pathways associated with various cancers, including melanoma, lung, liver, and acute leukemia. The ability of this class of molecules to regulate cell proliferation was first recognized in the model organism Drosophila and the fruit fly genetic model and continues to provide insight into the molecular mechanism by which this family of adapter molecules regulates both normal development and disease associated with corruption of their proper regulation and function.

Abstract

The Tribbles (Trib) family of pseudokinase proteins regulate cell growth, proliferation, and differentiation during normal development and in response to environmental stress. Mutations in human Trib isoforms (Trib1, 2, and 3) have been associated with metabolic disease and linked to leukemia and the formation of solid tumors, including melanomas, hepatomas, and lung cancers. Drosophila Tribbles (Trbl) was the first identified member of this sub-family of pseudokinases and shares a conserved structure and similar functions to bind and direct the degradation of key mediators of cell growth and proliferation. Common Trib targets include Akt kinase (also known as protein kinase B), C/EBP (CAAT/enhancer binding protein) transcription factors, and Cdc25 phosphatases, leading to the notion that Trib family members stand athwart multiple pathways modulating their growth-promoting activities. Recent work using the Drosophila model has provided important insights into novel facets of conserved Tribbles functions in stem cell quiescence, tissue regeneration, metabolism connected to insulin signaling, and tumor formation linked to the Hippo signaling pathway. Here we highlight some of these recent studies and discuss their implications for understanding the complex roles Tribs play in cancers and disease pathologies.

Lung cancer‑associated transcript 1 facilitates tumorigenesis in laryngeal squamous cell carcinoma through the targeted inhibition of miR‑493

Long non-coding RNAs (lncRNAs) serve important roles in the tumorigenesis of a diverse range of cancer types. The lung cancer-associated transcript 1 (LUCAT1), has been reported to promote the proliferation, migration and invasion of oral squamous cell carcinoma cells. However, the exact role of LUCAT1 in laryngeal squamous cell carcinoma (LSCC) remains to fully understood. The present study aimed to interrogate the role and modulatory mechanism of LUCAT1 in LSCC. Reverse transcription-quantitative PCR and western blotting were used to investigate the expression of LUCAT1 and miR-493, as well as the protein expression of cyclin-dependent kinase 2, cyclin E1, p21, matrix metalloproteinase (MMP)2, MMP9, vascular endothelial growth factor-C, Bcl-2, Bax, cleaved caspase-3 and procaspase-3. Cell Counting Kit-8, flow cytometry, wound healing and Transwell assays were performed to analyze the proliferation, cell cycle, apoptosis levels, and the migratory and invasive abilities, respectively, of the LSCC AMC-HN-8 cell line. In addition, dual-luciferase reporter and ribonucleoprotein immunoprecipitation assays were used to investigate the binding between LUCAT1 and microRNA (miR)-493. The results of the present study revealed that the expression levels of LUCAT1 were upregulated in AMC-HN-8 cells. The genetic knockdown of LUCAT1 expression levels significantly suppressed the cell proliferation, alongside downregulating the expression levels of CDK2 and cyclin E1 and upregulating p21 expression levels. In addition, the knockdown of LUCAT1 inhibited cell migration and invasion, as demonstrated using the wound healing and Transwell assays, respectively. Moreover, LUCAT1 knockdown promoted cell apoptosis and upregulated the expression levels of Bax and cleaved caspase-3, whilst downregulating the expression levels of Bcl-2. Furthermore, LUCAT1 was discovered to directly bind to and inhibit the well-known tumor suppressor, miR-493. Notably, the specific inhibition of miR-493 partly blocked the anticancer effects of LUCAT1 knockdown in AMC-HN-8 cells. In conclusion, these results suggested that LUCAT1 may facilitate tumorigenesis in LSCC through the targeted inhibition of miR-493, which provides evidence for a novel target for the treatment of LSCC.

Knockdown of lncRNA LINC01234 Suppresses the Tumorigenesis of Liver Cancer via Sponging miR-513a-5p

Background

Liver cancer is a frequent malignancy with poor prognosis and high mortality all over the world. It has been reported many lncRNAs could modulate the tumorigenesis of liver cancer. To identify novel potential targets for liver cancer, the differential expressed lncRNAs between liver cancer and adjacent normal tissues was analyzed with bioinformatics tool.

Methods

The differential expressed lncRNAs between liver cancer and adjacent normal tissues were analyzed with bioinformatics tool. Cell viability and proliferation was tested by CCK8 and Ki67, respectively. Apoptosis of liver cancer cells was tested by flow cytometry. Gene and protein expressions in liver cancer cells were measured by qRT-PCR and western blot, respectively. In vivo model of liver cancer was established to detect the effect of LINC01234 on liver cancer in vivo.

Results

LINC01234 was found to be negatively correlated with the survival rate of patients with liver cancer. Moreover, knockdown of LINC01234 significantly suppressed the proliferation and invasion of liver cancer cells via inducing the apoptosis. Meanwhile, miR-513a-5p was sponged by LINC01234, and USP4 was found to be a direct target of miR-513a-5p. In addition, LINC01234 knockdown inhibited the tumorigenesis of liver cancer via inactivating TGF-β signaling. Furthermore, silencing of LINC01234 notably inhibited the tumor growth of liver cancer in vivo.

Conclusion

Downregulation of LINC01234 could inhibit the tumorigenesis of liver cancer via mediation of miR-513a-5p/USP4/TGF-β axis. Thus, LINC01234 might serve as a new target for the treatment of liver cancer.