Long non-coding RNA HOTTIP promotes prostate cancer cells proliferation and migration by sponging miR-216a-5p

MALAT1 promotes FOXA1 degradation by competitively binding to miR-216a-5p and enhancing neuroendocrine differentiation in prostate cancer

OBJECTIVES

Prostate cancer (PC) is a leading cause of cancer-related death in males worldwide. Neuroendocrine differentiation (NED) is a feature of PC that often goes undetected and is associated with poor patient outcomes. Long non-coding RNAs (lncRNAs), microRNAs (miRNAs/miRs), and messenger RNAs (mRNAs) play important roles in the development and progression of PC.

METHODS

In this study, we used transcriptome sequencing and bioinformatics analysis to identify key regulators of NED in PC. Specifically, we examined the expression of PC-related lncRNAs, miRNAs, and mRNAs in PC cells and correlated these findings with NED phenotypes.

RESULTS

Our data revealed that metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and zinc finger protein 91 (ZFP91) were upregulated in PC, while miR-216a-5p was down-regulated. Ectopic expression of MALAT1 induced NED and promoted malignant phenotypes of PC cells. Furthermore, we found that MALAT1 competitively bound to miR-216a-5p, upregulated ZFP91, and promoted the degradation of forkhead box A1 (FOXA1), a key gene involved in NED of PC.

CONCLUSION

Taken together, these results suggest that MALAT1 plays an oncogenic role in NED and metastasis of PC via the miR-216a-5p/ZFP91/FOXA1 pathway. Our study highlights the potential of targeting this pathway as a novel therapeutic strategy for PC.

Investigation of the Use of Circulating Long Non-coding RNA HOXA Transcript at the Distal Tip (LncRNA HOTTIP) as a Biomarker in Breast Cancer

The critical need for new diagnostic and prognostic methods is highlighted by the fact that breast cancer continues to be the top cause of cancer-related deaths globally. Due to the dysregulation of long non-coding RNAs (lncRNAs) in numerous malignancies, they have become potential biomarkers in cancer. Recent research has focused on the lncRNA HOTTIP (HOXA transcript at the distal tip), which has a function in breast cancer metastasis and carcinogenesis. Until recently, HOTTIP had only been measured in cancer tissues and specimens. The aim of this study is to assess the amounts of the lncRNA HOTTIP in the blood serum of 46 breast cancer patients using real-time PCR analysis and identify the relationships between HOTTIP expression and several known clinical and pathological factors, including tumor grade, stage, lymph node involvement, hormone receptor status, and cell proliferation. The results of the study confirmed a positive relation of HOTTIP expression and breast cancer aggressiveness and metastatic behavior. The analysis results showed elevated HOTTIP values in stage III and T3/T4 tumors with multifocal characteristics and in lymph node involvement. Our findings raise the possibility of HOTTIP serving as a future prognostic biomarker for breast cancer patients.

Dynamic relationship between the aryl hydrocarbon receptor and long noncoding RNA balances cellular and toxicological responses

The aryl hydrocarbon receptor (AhR) is a cytosolic transcription factor activated by endogenous ligands and xenobiotic chemicals. Once the AhR is activated, it translocates to the nucleus, dimerizes with the AhR nuclear translator (ARNT) and binds to xenobiotic response elements (XRE) to promote gene transcription, notably the cytochrome P450 CYP1A1. The AhR not only mediates the toxic effects of environmental chemicals, but also has numerous putative physiological functions. This dichotomy in AhR biology may be related to reciprocal regulation of long non-coding RNA (lncRNA). lncRNA are defined as transcripts more than 200 nucleotides in length that do not encode a protein but are implicated in many physiological processes such as cell differentiation, cell proliferation, and apoptosis. lncRNA are also linked to disease pathogenesis, particularly the development of cancer. Recent studies have revealed that AhR activation by environmental chemicals affects the expression and function of lncRNA. In this article, we provide an overview of AhR signaling pathways activated by diverse ligands and highlight key differences in the putative biological versus toxicological response of AhR activation. We also detail the functions of lncRNA and provide current data on their regulation by the AhR. Finally, we outline how overlap in function between AhR and lncRNA may be one way in which AhR can be both a regulator of endogenous functions but also a mediator of toxicological responses to environmental chemicals. Overall, more research is still needed to fully understand the dynamic interplay between the AhR and lncRNA.

Connection of Cancer Exosomal LncRNAs, Sponging miRNAs, and Exosomal Processing and Their Potential Modulation by Natural Products

Cancerous exosomes contain diverse biomolecules that regulate cancer progression. Modulating exosome biogenesis with clinical drugs has become an effective strategy for cancer therapy. Suppressing exosomal processing (assembly and secretion) may block exosomal function to reduce the proliferation of cancer cells. However, the information on natural products that modulate cancer exosomes lacks systemic organization, particularly for exosomal long noncoding RNAs (lncRNAs). There is a gap in the connection between exosomal lncRNAs and exosomal processing. This review introduces the database (LncTarD) to explore the potential of exosomal lncRNAs and their sponging miRNAs. The names of sponging miRNAs were transferred to the database (miRDB) for the target prediction of exosomal processing genes. Moreover, the impacts of lncRNAs, sponging miRNAs, and exosomal processing on the tumor microenvironment (TME) and natural-product-modulating anticancer effects were then retrieved and organized. This review sheds light on the functions of exosomal lncRNAs, sponging miRNAs, and exosomal processing in anticancer processes. It also provides future directions for the application of natural products when regulating cancerous exosomal lncRNAs.

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.

DNMT1-mediated demethylation of lncRNA MEG3 promoter suppressed breast cancer progression by repressing Notch1 signaling pathway

Breast carcinoma is one of the common causes of cancer-related mortality in women. Maternally expressed gene 3 (MEG3), a lncRNA located at 14q32, can be involved in carcinogenesis. In this study, we discovered that MEG3 was downregulated by CpG hypermethylation within its gene promoter. Functionally, treatment of breast cancer cells with the DNA methylation inhibitor 5-AzadC as well as silencing of DNA methyltransferase-1 (DNMT1) could decrease the abnormal hypermethylation of the MEG3 promoter, reverse MEG3 expression, inhibit cell proliferation and promote cell apoptosis. In addition, we found that MEG3 expression was negatively correlated with DNMT1. Mechanistically, MEG3 knockdown combined with 5-AzadC or sh-DNMT1 treatment restored the expression of Notch1 receptor, leading to the Notch1 pathway activation, and promoted the progression of epithelial mesenchymal transformation (EMT). Finally, the mice tumor model experiments showed that DNMT1 knockdown can increase MEG3 expression and inhibit tumor growth. Collectively, our findings uncovered that DNMT1-mediated MEG3 demethylation leads to MEG3 upregulation, which in turn inhibits the Notch1 pathway and EMT process in breast cancer.

Molecular and cellular functions of long non-coding RNAs in prostate and breast cancer

Long noncoding RNAs (lncRNAs) are defined as noncoding RNA transcripts with a length greater than 200 nucleotides. Research over the last decade has made great strides in our understanding of lncRNAs, especially in the biology of their role in cancer. In this article, we will briefly discuss the biogenesis and characteristics of lncRNAs, then review their molecular and cellular functions in cancer by using prostate and breast cancer as examples. LncRNAs are abundant, diverse, and evolutionarily, less conserved than protein-coding genes. They are often expressed in a tumor and cell-specific manner. As a key epigenetic factor, lncRNAs can use a wide variety of molecular mechanisms to regulate gene expression at each step of the genetic information flow pathway. LncRNAs display widespread effects on cell behavior, tumor growth, and metastasis. They act intracellularly and extracellularly in an autocrine, paracrine and endocrine fashion. Increased understanding of lncRNA's role in cancer has facilitated the development of novel biomarkers for cancer diagnosis, led to greater understanding of cancer prognosis, enabled better prediction of therapeutic responses, and promoted identification of potential targets for cancer therapy.

Long non-coding RNA MCM3AP antisense RNA 1 silencing upregulates microRNA-24-3p to accelerate proliferation and migration of vascular endothelial cells in myocardial infarction rats by reducing EIF4G2

Long non-coding RNAs (lncRNAs) are crucial drivers in the progression of human diseases such as myocardial infarction (MI). However, the impact of lncRNA MCM3AP antisense RNA 1 (MCM3AP-AS1) on MI remains unknown. This research was determined to explore the effect of MCM3AP-AS1 modulating microRNA-24-3p (miR-24-3p) and eukaryotic translation initiation factor 4 gamma 2 (EIF4G2) on MI. The rat MI models were constructed and, respectively, treated with altered MCM3AP-AS1, miR-24-3p or/and EIF4G2. Subsequently, the cardiac function, myocardial pathological injury, malondialdehyde content and superoxide dismutase activity were determined. The vascular endothelial cells (VECs) were isolated and treated severally, and then proliferation and migration of VECs were measured. MCM3AP-AS1, miR-24-3p, EIF4G2 and vascular endothelial growth factor (VEGF) expressions in myocardial tissues and VECs were assessed. MCM3AP-AS1 and EIF4G2 were upregulated while miR-24-3p and VEGF were downregulated in MI rat myocardial tissues. MCM3AP-AS1 silencing or miR-24-3p elevation improved cardiac function and myocardial pathological injury, suppressed malondialdehyde content, and also enhanced VEGF expression and superoxide dismutase activity in MI rats. In VECs, downregulated MCM3AP-AS1 or upregulated miR-24-3p accelerated cell proliferation and migration. These effects of miR-24-3p upregulation were reversed by overexpressed EIF4G2. Our study summarizes that reduced MCM3AP-AS1 elevates miR-24-3p to promote proliferation and migration of MI rat VECs by inhibiting EIF4G2.

Crosstalk between Long Non Coding RNAs, microRNAs and DNA Damage Repair in Prostate Cancer: New Therapeutic Opportunities?

Simple Summary

Non-coding RNAs are a type of genetic material that doesn’t make protein, but performs diverse regulatory functions. In prostate cancer, most treatments target proteins, and resistance to such therapies is common, leading to disease progression. Targeting non-coding RNAs may provide alterative treatment options and potentially overcome drug resistance. Major types of non-coding RNAs include tiny ‘microRNAs’ and much longer ‘long non-coding RNAs’. Scientific studies have shown that these form a major part of the human genome, and play key roles in altering gene activity and determining the fate of cells. Importantly, in cancer, their activity is altered. Recent evidence suggests that microRNAs and long non-coding RNAs play important roles in controlling response to DNA damage. In this review, we explore how different types of non-coding RNA interact to control cell DNA damage responses, and how this knowledge may be used to design better prostate cancer treatments and tests.

Abstract

It is increasingly appreciated that transcripts derived from non-coding parts of the human genome, such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), are key regulators of biological processes both in normal physiology and disease. Their dysregulation during tumourigenesis has attracted significant interest in their exploitation as novel cancer therapeutics. Prostate cancer (PCa), as one of the most diagnosed malignancies and a leading cause of cancer-related death in men, continues to pose a major public health problem. In particular, survival of men with metastatic disease is very poor. Defects in DNA damage response (DDR) pathways culminate in genomic instability in PCa, which is associated with aggressive disease and poor patient outcome. Treatment options for metastatic PCa remain limited. Thus, researchers are increasingly targeting ncRNAs and DDR pathways to develop new biomarkers and therapeutics for PCa. Increasing evidence points to a widespread and biologically-relevant regulatory network of interactions between lncRNAs and miRNAs, with implications for major biological and pathological processes. This review summarises the current state of knowledge surrounding the roles of the lncRNA:miRNA interactions in PCa DDR, and their emerging potential as predictive and diagnostic biomarkers. We also discuss their therapeutic promise for the clinical management of PCa.

Molecular Mechanisms of lncRNAs in the Dependent Regulation of Cancer and Their Potential Therapeutic Use

Deep whole genome and transcriptome sequencing have highlighted the importance of an emerging class of non-coding RNA longer than 200 nucleotides (i.e., long non-coding RNAs (lncRNAs)) that are involved in multiple cellular processes such as cell differentiation, embryonic development, and tissue homeostasis. Cancer is a prime example derived from a loss of homeostasis, primarily caused by genetic alterations both in the genomic and epigenetic landscape, which results in deregulation of the gene networks. Deregulation of the expression of many lncRNAs in samples, tissues or patients has been pointed out as a molecular regulator in carcinogenesis, with them acting as oncogenes or tumor suppressor genes. Herein, we summarize the distinct molecular regulatory mechanisms described in literature in which lncRNAs modulate carcinogenesis, emphasizing epigenetic and genetic alterations in particular. Furthermore, we also reviewed the current strategies used to block lncRNA oncogenic functions and their usefulness as potential therapeutic targets in several carcinomas.

Cell Plasticity and Prostate Cancer: The Role of Epithelial-Mesenchymal Transition in Tumor Progression, Invasion, Metastasis and Cancer Therapy Resistance

Simple Summary

Although epithelial-to-mesenchymal transition (EMT) is a well-known cellular process involved during normal embryogenesis and wound healing, it also has a dark side; it is a complex process that provides tumor cells with a more aggressive phenotype, facilitating tumor metastasis and even resistance to therapy. This review focuses on the key pathways of EMT in the pathogenesis of prostate cancer and the development of metastases and evasion of currently available treatments.

Abstract

Prostate cancer, the second most common malignancy in men, is characterized by high heterogeneity that poses several therapeutic challenges. Epithelial–mesenchymal transition (EMT) is a dynamic, reversible cellular process which is essential in normal embryonic morphogenesis and wound healing. However, the cellular changes that are induced by EMT suggest that it may also play a central role in tumor progression, invasion, metastasis, and resistance to current therapeutic options. These changes include enhanced motility and loss of cell–cell adhesion that form a more aggressive cellular phenotype. Moreover, the reverse process (MET) is a necessary element of the metastatic tumor process. It is highly probable that this cell plasticity reflects a hybrid state between epithelial and mesenchymal status. In this review, we describe the underlying key mechanisms of the EMT-induced phenotype modulation that contribute to prostate tumor aggressiveness and cancer therapy resistance, in an effort to provide a framework of this complex cellular process.

MiR-216a-5p ameliorates learning-memory deficits and neuroinflammatory response of Alzheimer's disease mice via regulation of HMGB1/NF-κB signaling

OBJECTIVE

The objective of this study was to explore whether miR-216a-5p could affect the learning-memory ability and inflammatory response of Alzheimer's disease (AD) mice via regulation of the HMGB1/NF-κB pathway.

METHODS

Mice were divided into the normal (wild-type C57BL/6 mice), AD (APP/PS1 double-transgenic mice), AD + miR-216a-5p, and AD + vector groups. The Morris water maze test was used to examine learning and memory ability. Nissl staining and TUNEL staining were performed to observe the survival and apoptosis of hippocampal neurons. In addition, Aβ deposition and the expression of inflammatory cytokines were determined, while miR-216a-5p expression and HMGB1/NF-κB pathway-related proteins were detected by qRT-PCR and Western blotting, respectively.

RESULTS

AD mice exhibited decreased miR-216a-5p expression but increased HMGB-1 protein expression in the hippocampus, and these mice had a prolonged escape latency, fewer number of times crossing the platform location and shortened time in the target quadrant compared to those in normal mice. AD mice also had an elevated number of TUNEL-positive cells, increased deposition of Aβ, increased expression of inflammatory cytokines and decreased number of Nissl-positive cells. In addition, AD mice presented with downregulated expression of cytoplasmic NF-κB p65 protein but upregulated expression of nuclear NF-κB p65 protein. However, AD mice treated with miR-216a-5p exhibited significant improvements of the abovementioned parameters. The dual-luciferase reporter assay confirmed that HMGB1 is a target gene of miR-216a-5p.

CONCLUSION

MiR-216a-5p can improve learning-memory ability and attenuate the inflammatory response of AD mice through targeted inhibition of the HMGB1/NF-κB pathway.

miR-574-5p mediates epithelial-mesenchymal transition in small cell lung cancer by targeting vimentin via a competitive endogenous RNA network

Numerous studies have suggested that non-coding RNAs mediate tumorigenesis via the epithelial-mesenchymal transition (EMT). However, whether the long non-coding RNA (lncRNA) HOXA transcript at the distal tip (HOTTIP) plays a role in the EMT of small cell lung cancer (SCLC) remains unclear. The results of the present study suggest that HOTTIP-knockdown may lead to a significant increase in E-cadherin expression and a decrease in vimentin (VIM) expression; these proteins are two key markers of EMT. Furthermore, a notable morphological change in SCLC cells with HOTTIP-knockdown was observed: After upregulation of microRNA (miR)-574-5p, the cells exhibited a long, fusiform morphology. Investigating these phenomena further revealed that HOTTIP may participate in EMT by binding to miR-574-5p. In addition, using bioinformatics technology and a dual luciferase reporter assay, it was found that miR-574-5p inhibited VIM expression via direct binding and interaction. In summary, the present results indicate that HOTTIP may be involved in the EMT of SCLC by binding to miR-574-5p, and that miR-574-5p may act through VIM, which is a key marker of EMT.

Knockdown of lncRNA HOTTIP Inhibits Retinoblastoma Progression by Modulating the miR-101-3p/STC1 Axis

Objective:

Retinoblastoma (RB) is a frequent eye cancer in children. Long non-coding RNA (LncRNA) HOXA transcript at the distal tip (HOTTIP) is aberrantly expressed in cancer tissues. This study explores the underlying mechanism of lncRNA HOTTIP in RB.

Methods:

HOTTIP expression in normal retinal cells and RB cell lines was detected using qRT-PCR. The proliferation of RB cells was measured using CCK-8 and EdU assays, and apoptosis was detected using flow cytometry and Western blotting after the transfection of si-HOTTIP into Y79 cells and pc-HOTTIP into HXO-RB-44 cells. The target relationships between HOTTIP and miR-101-3p, and miR-101-3p and STC1 were predicted by bioinformatics website and verified using dual-luciferase reporter gene assay. The binding of HOTTIP and miR-101-3p was verified using RNA pull-down assay. STC1 mRNA and protein in RB cells were measured using qRT-PCR and Western blotting. Moreover, si-HOTTIP and in-miR-101-3p/in-NC, and si-HOTTIP and pc-STC1/pcDNA were co-transfected into Y79 cells respectively to evaluate cell proliferation and apoptosis. Xenograft study was conducted, and Ki67-positive expression was detected using immunohistochemical staining.

Results:

HOTTIP expression was promoted in RB tissues and cells. Downregulation of HOTTIP inhibited proliferation and promoted apoptosis of Y79 cells, while upregulation of HOTTIP promoted proliferation and inhibited apoptosis of HXO-RB-44 cells. There were target relationships between HOTTIP and miR-101-3p, and miR-101-3p and STC1. Inhibition of miR-101-3p or overexpression of STC1 reversed the effect of si-HOTTIP on the proliferation and apoptosis of RB cells. Xenograft study showed that knockdown of HOTTIP suppressed the growth of RB in vitro.

Conclusion:

It could be concluded that HOTTIP sponged miR-101-3p to upregulate STC1 expression, thereby promoting RB cell proliferation and inhibiting apoptosis.

The Role of LncRNAs in Translation

Long non-coding RNAs (lncRNAs), a group of non-protein coding RNAs with lengths of more than 200 nucleotides, exert their effects by binding to DNA, mRNA, microRNA, and proteins and regulate gene expression at the transcriptional, post-transcriptional, translational, and post-translational levels. Depending on cellular location, lncRNAs are involved in a wide range of cellular functions, including chromatin modification, transcriptional activation, transcriptional interference, scaffolding and regulation of translational machinery. This review highlights recent studies on lncRNAs in the regulation of protein translation by modulating the translational factors (i.e, eIF4E, eIF4G, eIF4A, 4E-BP1, eEF5A) and signaling pathways involved in this process as wells as their potential roles as tumor suppressors or tumor promoters.

Non-Coding RNAs Set a New Phenotypic Frontier in Prostate Cancer Metastasis and Resistance

Prostate cancer (PCa) mortality remains a significant public health problem, as advanced disease has poor survivability due to the development of resistance in response to both standard and novel therapeutic interventions. Therapeutic resistance is a multifaceted problem involving the interplay of a number of biological mechanisms including genetic, signaling, and phenotypic alterations, compounded by the contributions of a tumor microenvironment that supports tumor growth, invasiveness, and metastasis. The androgen receptor (AR) is a primary regulator of prostate cell growth, response and maintenance, and the target of most standard PCa therapies designed to inhibit AR from interacting with androgens, its native ligands. As such, AR remains the main driver of therapeutic response in patients with metastatic castration-resistant prostate cancer (mCRPC). While androgen deprivation therapy (ADT), in combination with microtubule-targeting taxane chemotherapy, offers survival benefits in patients with mCRPC, therapeutic resistance invariably develops, leading to lethal disease. Understanding the mechanisms underlying resistance is critical to improving therapeutic outcomes and also to the development of biomarker signatures of predictive value. The interconversions between epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET) navigate the prostate tumor therapeutic response, and provide a novel targeting platform in overcoming therapeutic resistance. Both microRNA (miRNA)- and long non-coding RNA (lncRNA)-mediated mechanisms have been associated with epigenetic changes in prostate cancer. This review discusses the current evidence-based knowledge of the role of the phenotypic transitions and novel molecular determinants (non-coding RNAs) as contributors to the emergence of therapeutic resistance and metastasis and their integrated predictive value in prostate cancer progression to advanced disease.

Long non-coding RNAs (lncRNAs) in spermatogenesis and male infertility

BACKGROUND

Long non-coding RNAs (lncRNAs) have a size of more than 200 bp and are known to regulate a host of crucial cellular processes like proliferation, differentiation and apoptosis by regulating gene expression. While small noncoding RNAs (ncRNAs) such as miRNAs, siRNAs, Piwi-interacting RNAs have been extensively studied in male germ cell development, the role of lncRNAs in spermatogenesis remains largely unknown.

OBJECTIVE

In this article, we have reviewed the biology and role of lncRNAs in spermatogenesis along with the tools available for data analysis.

RESULTS AND CONCLUSIONS

Till date, three microarray and four RNA-seq studies have been undertaken to identify lncRNAs in mouse testes or germ cells. These studies were done on pre-natal, post-natal, adult testis, and different germ cells to identify lncRNAs regulating spermatogenesis. In case of humans, five RNA-seq studies on different germ cell populations, including two on sperm, were undertaken. We compared three studies on human germ cells to identify common lncRNAs and found 15 lncRNAs (LINC00635, LINC00521, LINC00174, LINC00654, LINC00710, LINC00226, LINC00326, LINC00494, LINC00535, LINC00616, LINC00662, LINC00668, LINC00467, LINC00608, and LINC00658) to show consistent differential expression across these studies. Some of the targets of these lncRNAs included CENPB, FAM98B, GOLGA6 family, RPGR, TPM2, GNB5, KCNQ10T1, TAZ, LIN28A, CDKN2B, CDKN2A, CDKN1A, CDKN1B, CDKN1C, EZH2, SUZ12, VEGFA genes. A lone study on human male infertility identified 9879 differentially expressed lncRNAs with three (lnc32058, lnc09522, and lnc98497) of them showing specific and high expression in immotile sperm in comparison to normal motile sperm. A few lncRNAs (Mrhl, Drm, Spga-lncRNAs, NLC1-C, HongrES2, Tsx, LncRNA-tcam1, Tug1, Tesra, AK015322, Gm2044, and LncRNA033862) have been functionally validated for their roles in spermatogenesis. Apart from rodents and humans, studies on sheep and bull have also identified lncRNAs potentially important for spermatogenesis. A number of these non-coding RNAs are strong candidates for further research on their roles in spermatogenesis.

LncRNA DANCR regulates the growth and metastasis of oral squamous cell carcinoma cells via altering miR-216a-5p expression

The study aims to investigate how DANCR can alter the growth and metastasis of oral squamous cell carcinoma (OSCC) cells by regulating miR-216a-5p. The expression of DANCR and miR-216a-5p in OSCC patients and cells were measured. SCC15 and CAL-27 cells were selected to divide into Control, sh-NC, DANCR shRNA, DANCR, miR-216a-5p mimic, and DANCR + miR-216a-5p mimic groups. Dual-luciferase reporter gene assay was performed for the verification of the targeting relationship between miR-216a-5p and DANCR/Bcl-2/KLF12. We also quantified the abilities of OSCC cells regarding proliferation, invasion, migration and apoptosis, and the expression levels of apoptosis-related proteins were measured. Finally, the tumor-bearing nude mice were established to verify the effect of DANCR in vivo. Up-regulated DANCR expression and down-regulated miR-216a-5p expression were observed in both OSCC tissues and cells, and they were proven strongly correlated to the histological grade, clinical staging and lymph node metastasis of OSCC patients. Dual-luciferase reporter gene assay showed a target relationship between DANCR and miR-216a-5p, as well as between miR-216a-5p and Bcl-2/KLF12. Both DANCR shRNA and miR-216a-5p mimic decreased proliferative, migration and invasive abilities of OSCC cells with increased cell apoptosis. However, DANCR group showed completely opposite trends. Moreover, miR-216a-5p mimic could reverse the role of DANCR in promoting tumor growth. In-vivo experiment confirmed the inhibitory role of DANCR shRNA in tumor growth and metastasis. We concluded that DANCR may promote the growth and metastasis of OSCC cells and suppress OSCC cell apoptosis by sponging miR-216a-5p.

Long noncoding RNA HOTTIP promotes the metastatic potential of ovarian cancer through the regulation of the miR-615-3p/SMARCE1 pathway

Upregulation of lncRNA HOXA transcript at the distal tip (HOTTIP) plays important roles in cancer progression. Nevertheless, its functions in the growth and metastasis of ovarian carcinoma are unknown. In this study, we demonstrated overexpression of HOTTIP in ovarian cancer cell lines and clinical tissues. Further, we showed that higher level of HOTTIP was associated with poor survival of ovarian cancer patients. Notably, HOTTIP silencing restrained proliferation, migration, and invasiveness of ovarian carcinoma cells. On the other hand, upregulation of HOTTIP remarkably exacerbated the aggressive traits of ovarian carcinoma cells. In addition, HOTTIP served as a sponge of miR-615-3p to upregulate SMARCE1 level. Further, upregulation of miR-615-3p or downregulation of SMARCE1 reversed the carcinogenic impacts of HOTTIP in ovarian cancer. HOTTIP and miR-615-3p expression levels in ovarian cancer cells were negatively correlated, whereas HOTTIP and SMARCE1 expression levels were positively correlated. In nude mice, downregulation of HOTTIP reduced cell growth in vivo. In summary, lncRNA HOTTIP promotes the growth and metastatic phenotypes of ovarian cancer via regulating miR-615-3p/SMARCE1 pathway.

MiR-216a-5p inhibits tumorigenesis in Pancreatic Cancer by targeting TPT1/mTORC1 and is mediated by LINC01133

MiR-216a-5p has opposite effects on tumorigenesis and progression in the context of different tumors, acting as either a tumor suppressor or an oncogene. However, the expression and function of miR-216a-5p in pancreatic cancer (PC) is not well characterized. In this study, we found miR-216a-5p was significantly downregulated in PC tissues and cell lines, which showed a negative correlation with peripancreatic lymph, perineural invasion and TNM stage of PCs patients. We made use of functional assays to reveal that miR-216a-5p inhibited growth and migration of PC cells in vitro and in vivo. Then, by employing the bioinformatics analysis and luciferase reporter assay, we demonstrated TPT1 was a potential target of miR-216a-5p, which contributes to tumor malignance by mediating mTORC1 pathway-associated autophagy. Furthermore, bioinformatics analysis and RNA pulldown confirmed that miR-216a-5p was mediated by LINC01133, which sponge miR-216a-5p, as a competing endogenous RNA (ceRNA). Collectively, our study revealed an important role of LINC01133/miR-216a-5p/TPT1 axis in the genesis and progression of PCs, which provides potential biomarkers for clinical diagnosis and therapy of PCs.

HOTTIP Predicts Poor Survival in Gastric Cancer Patients and Contributes to Cisplatin Resistance by Sponging miR-216a-5p

Gastric cancer (GC) is a significant public health burden worldwide, and cisplatin resistance is the leading cause for the failure of chemotherapy in this disease. Previous studies have revealed that HOXA transcript at the distal tip (HOTTIP) is involved in the pathology of GC and is associated with poor overall survival. However, the functional role of HOTTIP in GC chemoresistance remains unclear. In this study, quantitative real-time PCR was used to analyze HOTTIP expression in GC cell lines and in tissues of GC patients who received cisplatin-based chemotherapy. The mechanism of HOTTIP-mediated chemoresistance was assessed using cell viability, apoptosis, and autophagy assays. The relationships among HOTTIP, miR-216a-5p, and Bcl-2 were determined using luciferase reporter and western blot assays. HOTTIP was markedly upregulated in the tissues of GC patients who were treated with gastrectomy and cisplatin chemotherapy, especially in those with recurrent tumors. Further, HOTTIP was increased in the cisplatin-resistant cell line, SGC7901/DDP, compared to the parental cells, SGC7901. Functional assays demonstrated that HOTTIP expression promoted cisplatin resistance and inhibited apoptosis and autophagy in GC cells. Mechanistic investigations revealed that HOTTIP may regulate the functions of GC cells by sponging miR-216a-5p. MiR-216a-5p overexpression decreased Bcl-2 expression, enhanced Beclin1 expression, and active autophagy. Taken together, our study demonstrated that HOTTIP is closely associated with recurrence in GC patients. HOTTIP expression confers cisplatin resistance by regulating the miR-216a-5p/BCL-2/Beclin1/autophagy pathway, which provides a novel strategy to overcome resistance to chemotherapy in GC.

MicroRNA-216a inhibits neuronal apoptosis in a cellular Parkinson's disease model by targeting Bax

The study found that microRNAs play an important role in Parkinson's disease (PD). However, the function of MicroRNA-216a (miR-216a) in PD is unclear. Therefore, this experiment aimed to investigate the pathogenesis of miR-216a in PD. Using the toxicity of MPP+ to polyhexamine neurons, apoptosis of SH-SY5Y neuroblastoma cells was induced at different time by MPP+ to construct a stable acute PD cell model. The effects of DNA breakage, mitochondrial membrane potential (A ^ m), caspase-3 activity and nucleosome enrichment on cell apoptosis were detected by flow cytometry, TUNEL. MPP+ increased the toxic effects of dopaminergic neurons in a PD model. The introduction of miR-216a inhibited MPP + -induced neuronal apoptosis. The main manifestations were the decreased levels of positive rate of Tunel cells, caspase 3 activity and nucleosome enrichment factor. Bax was a direct target of miR-216a. In addition, Bax overexpression reversed the effects of miR-216a on neural cells. Bax downstream factors were also involved in miR-216a regulation of MPP + -triggered neuronal apoptosis. miR-216a regulated the progression of PD by regulating Bax, and miR-216a may be a potential target for PD.

A comprehensive review of the role of long non-coding RNAs in organs with an endocrine function

Long non-coding RNAs (lncRNAs) are transcripts with sizes larger than 200 nucleotides and no/ small open reading frame that cannot produce functional proteins. The number of these transcripts surpasses the number of coding genes. LncRNAs regulate many aspects of cell functions such as proliferation, cell cycle transition and differentiation; so their dysregulation has pervasive effects on cell phenotype. Increasing numbers of these transcripts have been shown to participate in the pathogenesis of cancer. In the current review, we summarize recent findings regarding the role of lncRNAs in tumors originated from organs which have an endocrine function. We mostly focused on adrenal, pancreas and pituitary gland as prototypes of these organs. Moreover, we presented the obtained data of the role of lncRNAs in prostate, ovarian and testicular cancers. Recent data highly supports the role of lncRNAs in the pathogenesis of cancers originated from these organs. Moreover, certain genomic loci within lncRNAs have been shown to be associated with risk of these cancers. Diagnostic and prognostic role of some lncRNAs in these cancers have been evaluated recently. Taken together, lncRNAs are putative biomarkers for cancers originated from organs which have an endocrine function.

Human Long Noncoding RNA Interactome: Detection, Characterization and Function

The application of a new generation of sequencing techniques has revealed that most of the genome has already been transcribed. However, only a small part of the genome codes proteins. The rest of the genome "dark matter" belongs to divergent groups of non-coding RNA (ncRNA), that is not translated into proteins. There are two groups of ncRNAs, which include small and long non-coding RNAs (sncRNA and lncRNA respectively). Over the last decade, there has been an increased interest in lncRNAs and their interaction with cellular components. In this review, we presented the newest information about the human lncRNA interactome. The term lncRNA interactome refers to cellular biomolecules, such as nucleic acids, proteins, and peptides that interact with lncRNA. The lncRNA interactome was characterized in the last decade, however, understanding what role the biomolecules associated with lncRNA play and the nature of these interactions will allow us to better understand lncRNA's biological functions in the cell. We also describe a set of methods currently used for the detection of lncRNA interactome components and the analysis of their interactions. We think that such a holistic and integrated analysis of the lncRNA interactome will help to better understand its potential role in the development of organisms and cancers.

Long noncoding RNA HOTTIP overexpression: A potential prognostic biomarker in prostate cancer

HOXA transcript at the distal tip (HOTTIP) is a long noncoding RNA (lncRNA), which is >200 nucleotides in length. HOTTIP expression has been demonstrated to play a crucial oncogenic role in cancer pathogenesis, and is said to be associated with poor human cancer prognosis. In prostate cancer, HOTTIP has been identified as an oncogene, but its clinicopathologic significance remains unclear. Array-based qRT-PCR was used to investigate lncRNA levels in 10 pairs of prostate cancer tissues and non-neoplastic parenchyma. Tissue microarray (TMA) was constructed using a total of 70 surgically resected prostatic adenocarcinoma tissues obtained from the Korea University Anam Hospital from 2009 to 2013. HOTTIP expression was determined by RNA in situ hybridization(ISH) and was correlated with clinicopathologic features. Increased HOTTIP expression was observed in all available prostate cancer tissue specimens compared with that in paired normal tissue. High HOTTIP expression was positively associated with bad clinicopathologic features, including higher pathologic T stage (p < 0.001), presence of extraprostatic extension (p < 0.001), seminal vesicle invasion (p < 0.001), perineural invasion (p < 0.001), and the tumor involvement of resection margin (p = 0.044). In particular, significantly increased HOTTIP expression was observed in specimens from patients in the high or very high-risk group, according to the 2018 National Comprehensive Cancer Network (NCCN) guidelines (p < 0.001). Also, patients with high HOTTIP expression showed poorer overall survival than those with low expression. In conclusion, we analytically validated the poor prognostic significance of HOTTIP overexpression and its association with bad clinicopathologic features, and present HOTTIP as a potential prognostic biomarker in prostate cancer.

Regulatory effect of miR-216a-5p on XIAP-mediated differentiation, proliferation, and apoptosis of acinar cells in acute pancreatitis

BACKGROUND

Severe acute pancreatitis (AP) is a common critical illness in the digestive system. It is difficult to treat clinically and has a high mortality rate, which seriously endangers patients' lives. In recent years, the differential expression of multiple miRNAs has been found to be closely related to the development, diagnosis, and prognosis of AP. Further exploration of the role of miRNAs in the development, com-plications, and other aspects of AP may provide new clues to the diagnosis and treatment of AP. It has been found that miR-216a-5p can inhibit the invasion of lung cancer cells by down-regulating MMP16; miR-216a-5p can inhibit the proliferation of bladder cancer cells and promote their apoptosis by targeting the PAK2 gene. In addition, miR-216a-5p can inhibit the malignant progression of small cell lung cancer and affect the proliferation, migration, and tumorigenesis of prostate cancer cells. Although it has been found that miR-216a is highly expressed in peripheral blood of patients with AP, the effect and mechanism of miR-216a-5p in the proliferation and apoptosis of AP cells are still unclear.

AIM

To investigate the effects of miR-216a-5p on proliferation and apoptosis of AP acinar cells and the potential mechanism involved.

METHODS

Pancreatic acinar AR42J cells were treated with cerulein to construct an AP model. The cells were then transfected with miR-NC, miR-216a-5p mimic, anti-miR-NC, anti-miR-216a-5p, pcDNA3.1, pcDNA3.1-XIAP, anti-miR-216a-5p + si-NC, and anti-miR-216a-5p + si-XIAP by the liposome method. The expression of miR-216a-5p in AR42J cells was detected by qRT-PCR, and protein expression was detected by Western blot. MTT assay was used to detect cell viability, flow cytometry was used to detect apoptosis, and dual luciferase reporter gene assay was used to detect fluorescence activity.

Results

The expression of miR-216a-5p was significantly increased after treatment of AR42J cells with cerulein (P < 0.05). Cell viability was significantly increased and the apoptosis rate was significantly decreased by inhibiting the expression of miR-216a-5p and overexpressing XIAP; the expression levels of Cyclin D1 and Bcl-2 proteins were significantly increased, and the expression levels of P21 and Bax proteins were significantly decreased (P < 0.05). MiR-216a-5p negatively regulated the expression of XIAP, and inhibition of XIAP expression reversed the inhibitory effect of miR-216a-5p in proliferation promotion and apoptosis inhibition of cerulein-treated AR42J cells.

Conclusion

Inhibition of miR-216a-5p expression can inhibit the apoptosis of pancreatic acinar cells and promote their proliferation via mechanisms that may be related to the targeted regulation of XIAP. Our findings may provide new targets and new ideas for the diagnosis and treatment of AP.

Downregulation of miR-216a-5p by long noncoding RNA PVT1 suppresses colorectal cancer progression via modulation of YBX1 expression

Purpose

Increasing evidence has demonstrated that microRNAs (miRNAs) are closely related to the occurrence and development of tumors. MiR-216a-5p, located at 2p16.1, has been shown to suppress proliferation of cancerous cells. However, its expression and function in colorectal cancer (CRC) remain unclear.

Materials and methods

The significance of miR-216a-5p in CRC was studied by analyzing miR-216a-5p expression in CRC tissues and its association with clinicopathological parameters. CRC cells, stably overexpressing miR-216a-5p, were evaluated for cell proliferation and metastasis using cell counting kit-8 (CCK-8) and transwell assay methods. Epithelial–mesenchymal transition (EMT) pathway was analyzed by Western blotting. Bioinformatics, quantitative real-time polymerase chain reaction (RT-qPCR), and luciferase reporter assay were performed to define the regulation of PVT1/miR-216a-5p/Y Box Binding Protein 1 (YBX1) axis in CRC.

Results

The expression of miR-216a-5p was found to be significantly downregulated in CRC and was correlated with the various stages and differentiation degree of the tumors. Moreover, the overexpression of miR-216a-5p could significantly inhibit the tumor growth, metastasis, and EMT progression in CRC. Furthermore, the expression of miR-216a-5p was negatively correlated with the expression of PVT1, and PVT1 could reverse tumor suppressive effect of miR-216a-5p in CRC cells. Finally, YBX1 might be the key target of PVT1/miR-216a-5p axis in CRC.

Conclusion

Downregulation of miR-216a-5p by PVT1 could suppress CRC progression via modulating YBX1 expression.

HOTTIP Functions as a Key Candidate Biomarker in Head and Neck Squamous Cell Carcinoma by Integrated Bioinformatic Analysis

Background

Accumulating evidence has demonstrated the pivotal role of long noncoding RNAs (lncRNAs) in competing endogenous RNA (ceRNA) networks for predicting survival and evaluating prognosis in cancer patients. However, the pathogenesis of head and neck squamous cell carcinoma (HNSCC) remains unclear, and prognostic biomarkers for HNSCC are still lacking.

Methods

A total of 546 RNA sequencing profiles of HNSCC patients with clinical outcome data were obtained from the Cancer Genome Atlas (TCGA) database, providing a large sample of RNA sequencing data. From these, 71 Long noncoding RNAs lncRNAs, 8 microRNAs (miRNAs), and 16 messenger RNAs (mRNAs) were identified to construct a HNSCC-specific ceRNA network (fold change >2, P < 0.05). Univariate and multivariate Cox proportional regression models were used to assess independent indicators of prognosis. Then the expression of lncRNAs harboring prognostic value was validated in human HNSCC cell lines and tumor samples from our cohort and another two datasets from GEO (Gene Expression Omnibus) databases.

Results

As a result, a 3-mRNA signature and 6-lncRNA signature were identified. The six-lncRNA signature exhibited the highest prognostic value. Notably, in the six lncRNAs, HOTTIP showed the greatest prognostic value and was significantly correlated with clinical stage and histological grade of HNSCC patients. Furthermore, it was proved that HOTTIP was upregulated in HNSCC cell lines and cancerous tissues compared with corresponding normal cell lines and normal tissues. Functional assessment analysis revealed that HOTTIP might play a key role in the oncogenesis and progression of HNSCC.

Conclusion

The present study deepened our understanding of the ceRNA-related regulatory mechanism in the pathogenesis of HNSCC and identified candidate prognostic biomarkers for clinical outcome prediction in HNSCC. HOTTIP may function as a key candidate biomarker in HNSCC and serve as a prognostic marker for HNSCC patients.

The long noncoding RNA HOTTIP promotes breast cancer cell migration, invasiveness, and epithelial-mesenchymal transition via the Wnt-β-catenin signaling pathway

Long noncoding RNA HOTTIP (HOXA transcript at the distal tip) has recently been reported to have a role in the proliferation of various cancer cells, yet its role in cell migration, invasiveness, and the EMT (epithelial-mesenchymal transition) in breast cancer and the potential mechanisms remain unknown. Breast cancer cell lines MDA-MB-231 and MDA-MB-468 were transfected with shRNA (short hairpin RNA) that specifically targeting HOTTIP. We observed a remarkable decrease in migration and invasiveness in these two breast cancer cell lines after knock-down of HOTTIP by shHOTTIP. We also demonstrated that the EMT of these two breast cell lines was suppressed after HOTTIP knock-down, as evidenced by increased E-cadherin levels, and decreased levels of N-cadherin, Snail, and Twist. Moreover, HOTTIP silencing also suppressed tumor metastasis in nude mice in vivo. In addition, we found that the expression of β-catenin was significantly decreased in breast cancer cells after knock-down of HOTTIP. In a further rescue experiment using overexpression of β-catenin, the rates of cell migration, invasiveness, and EMT of HOTTIP-silenced breast cancer cells were promoted, disclosing a potential role of the Wnt-β-catenin signaling pathway in this process. Overall, we discovered the positive regulatory function of HOTTIP in the migration, invasiveness, and EMT of breast cancer cells, via regulating the Wnt-β-catenin pathway.

miR-216a-5p promotes mesangial cell proliferation by targeting FoxO1 in diabetic nephropathy

BACKGROUND

Diabetic nephropathy (DN) is a leading cause of end-stage renal disease worldwide. microRNAs (miRNAs) have been reported to play essential roles in DN progression. However, the mechanism of miR-216a-5p on DN progression is still unclear.

METHODS

A DN model was established in human mesangial cells (HMC) by high glucose treatment. Cell proliferation was investigated using the cell counting kit-8 (CCK-8) assay. The cell cycle was measured through a propidium iodide (PI) cell cycle kit with flow cytometry. The interaction between miR-216a-5p and forkhead boxO1 (FoxO1) was probed by a bioinformatics analysis and luciferase activity assay. The expression of miR-216a-5p was detected using a quantitative real-time polymerase chain reaction (qRT-PCR). The abundances of FoxO1 and cell cycle-related cyclinD1, cyclin-dependent kinase 4 (CDK4), CDK6 and p27 were examined by qRT-PCR and Western blots (WB).

RESULTS

miR-216a-5p was up-regulated while FoxO1 was down-regulated in DN tissues. Moreover, miR-216a-5p promoted cell proliferation by regulating the cell cycle in high glucose-treated HMC cells. Notably, FoxO1 was a direct target and negatively correlated with miR-216a-5p. In addition, miR-216a induced cyclinD1, CDK4 and CDK6 but inhibited p27 expressions at the mRNA and protein levels. Furthermore, FoxO1 restoration reversed the regulatory effect of miR-216a on the cell cycle by regulating cyclinD1, CDK4, CDK6 and p27 abundances at the mRNA and protein levels.

CONCLUSION

miR-216a-5p is ectopic in DN and it promotes cell proliferation through regulating the cell cycle by targeting FoxO1 in high glucose-stimulated HMC cells, indicating it may serve as a novel biomarker for DN treatment.

lncRNA A1BG-AS1 suppresses proliferation and invasion of hepatocellular carcinoma cells by targeting miR-216a-5p

Extensive evidence indicate that long noncoding RNAs (lncRNAs) regulates the tumorigenesis and progression of hepatocellular carcinoma (HCC). However, the expression and biological function of lncRNA A1BG antisense RNA 1 (A1BG-AS1) were poorly known in HCC. Here, we found the underexpression of A1BG-AS1 in HCC via analysis of The Cancer Genome Atlas database. Further analyses confirmed that A1BG-AS1 expression in HCC was markedly lower than that in noncancerous tissues based on our HCC cohort. Clinical association analysis revealed that low A1BG-AS1 expression correlated with poor prognostic features, such as microvascular invasion, high tumor grade, and advanced tumor stage. Follow-up data indicated that low A1BG-AS1 level evidently correlated with poor clinical outcomes of HCC patients. Moreover, forced expression of A1BG-AS1 repressed proliferation, migration, and invasion of HCC cells in vitro. Conversely, A1BG-AS1 knockdown promoted these malignant behaviors in HepG2 cells. Mechanistically, A1BG-AS1 functioned as a competing endogenous RNA by directly sponging miR-216a-5p in HCC cells. Notably, miR-216a-5p restoration rescued A1BG-AS1 attenuated proliferation, migration and invasion of HCCLM3 cells. A1BG-AS1 positively regulated the levels of phosphatase and tensin homolog and SMAD family member 7, which were reduced by miR-216a-5p in HCC cells. Altogether, we conclude that A1BG-AS1 exerts a tumor suppressive role in HCC progression.

DANCR contributed to hepatocellular carcinoma malignancy via sponging miR-216a-5p and modulating KLF12

Long noncoding RNA (lncRNA) differentiation antagonizing nonprotein coding RNA (DANCR) has been identified as an oncogene in several cancers. However, the biological function and role of DANCR in hepatocellular carcinoma (HCC) remain unclear. Our current study aimed to investigate the detailed mechanism of DANCR in HCC. We found that DANCR was significantly upregulated in HCC cell lines in comparison to LO2 cells. Then, we observed that knockdown of DANCR could greatly inhibit Huh7 and HepG2 cell proliferation. In addition, HCC cell apoptosis was increased by silence of DANCR and meanwhile, cell cycle progression was blocked in G1 phase. Apart from these, downregulation of DANCR repressed HCC cell migration and invasion ability obviously. As predicted by the bioinformatics analysis, microRNA-216a-5p (miR-216a-5p) could serve as a direct target of DANCR. MiR-216a-5p has been reported to be involved in many cancers. Here, the correlation between miR-216a-5p and DANCR was confirmed using dual-luciferase reporter assay and radioimmunoprecipitation assay. Subsequently, Kruppel-like factor 12 (KLF12) exerts an important role in different tumor types. KLF12 can function as a downstream target of miR-216a-5p. Finally, the in vivo experiments were used and the data proved that DANCR also strongly suppressed HCC tumor growth in vivo via targeting miR-216a-5p and KLF12. In conclusion, our study indicated that DANCR might provide a new perspective for HCC treatment.

Knockdown of HOXA transcript at the distal tip suppresses the growth and invasion and induces apoptosis of oral tongue squamous carcinoma cells

Background

Oral tongue squamous cell carcinoma (OTSCC) is an aggressive cancer which has high mortality rates. HOXA transcript at the distal tip (HOTTIP) is a lncRNA that can be used as a prognostic marker in multiple carcinomas. The expression of HOTTIP is found to be elevated in OTSCC tissues, and such elevation is correlated with poor prognosis. However, its functional role in regulating the growth and metastasis of OTSCC cells remains elusive and requires further investigation.

Methods

HOTTIP-silenced OTSCC cells were established by inhibiting HOTTIP expression via its exclusive shRNA. Whether HOTTIP knockdown affected the aggressive tumor behaviors of OTSCC cells was investigated in vitro and in vivo.

Results

We found that HOTTIP shRNA restrained the cell proliferation and arrested the cell cycle at G1 phase in TSCCA and TCA8113 cells. The expression levels of cyclins B, D1, and E were downregulated in HOTTIP-silenced cells. HOTTIP silencing suppressed the growth of xenograft tumors. Moreover, the silencing of HOTTIP triggered apoptosis in TSCCA and TCA8113 cells and altered the expression of a group of apoptosis-related molecules: downregulated Bcl-2, upregulated Bax, and enhanced the cleavage of caspase 3 and PARP. Knockdown of HOTTIP also suppressed the migration, invasion, and epithelial-mesenchymal transition (EMT) of both TSCCA and TCA8113 cell lines.

Conclusion

Our findings suggest that HOTTIP is required by the OTSCC cells to maintain their growth and metastasis in vitro. It may serve as a promising potential candidate for OTSCC therapy.