Long noncoding RNA HNF1A-AS1 indicates a poor prognosis of colorectal cancer and promotes carcinogenesis via activation of the Wnt/β-catenin signaling pathway

The closed loop of the circCLIP2/miR-361-3p/STAT2 signaling axis regulates the progression of cervical cancer

BACKGROUND

Circular RNAs (circRNAs) are involved in tumorigenesis and the progression of cancer through various pathways. However, the detailed regulatory mechanisms of circRNAs in cervical cancer are not fully understood. The present study was designed to explore the biological functions and potential mechanisms of circCLIP2 (has_circ_0001717) in cervical cancer.

METHODS

The expression profiles of circRNAs in cancerous and adjacent normal tissues of cervical cancer patients were examined using RNA sequencing. Gain- and loss-of-function experiments were carried out to determine the biological functions of circCLIP2 in the proliferation, invasion, migration and apoptosis of cervical cancer cells. qRT-PCR was also used to evaluate the expression of circCLIP2, miR-361-3p and STAT2 in cervical cancer cells. The protein levels of STAT2 were determined by western blotting.

RESULTS

CircCLIP2 was identified as the most down-regulated molecule in the cancerous tissues of cervical cancer patients compared to the adjacent normal tissues. Moreover, the levels of circCLIP2 was decreased in cervical cancer patients with metastasis and advanced tumour stage, and patients with high-circCLIP2-expression exhibited poorer survival rate. In addition, over-expression of circCLIP2 suppressed the proliferation, invasion and migration of cervical cancer cells, whereas cell apoptosis was enhanced. Moreover, down-regulated circCLIP2 functioned as the sponge of miR-361-3p, which reduced the expression of STAT2. Furthermore, knockdown of STAT2 inhibited the expression of circCLIP2 at the transcriptional level.

CONCLUSION

The circCLIP2/miR-361-3p/STAT2 signalling could mediate the progression of cervical cancer. CircCLIP2 may become a novel target for the diagnosis and treatment of cervical cancer.

Reciprocal interactions between lncRNAs and MYC in colorectal cancer: partners in crime

Proto-oncogenic MYC is frequently dysregulated in colorectal cancer (CRC). In the past decades, long noncoding RNAs (lncRNAs) have emerged as important regulators in cancers, acting as scaffolds, molecular decoys, post-transcriptional regulators, and others. Interestingly, lncRNAs are able to control MYC expression both at transcriptional and post-transcriptional levels. It is suggested that the reciprocal interaction of MYC and lncRNAs often occurs in CRC. MYC can affect the cell fate by promoting or inhibiting the transcription of some lncRNAs. At the same time, some lncRNAs can also affect MYC expression or transcriptional activity, and in turn decide the cell fate. In this review we summarized the current knowledge about the MYC and lncRNA axis, focusing on its mutual regulation, roles in CRC, and proposed potential therapeutic prospects for CRC treatment.

CMYC-initiated HNF1A-AS1 overexpression maintains the stemness of gastric cancer cells

Cancer stem cells (CSCs) are believed to be responsible for cancer metastasis and recurrence due to their self-renewal ability and resistance to treatment. However, the mechanisms that regulate the stemness of CSCs remain poorly understood. Recently, evidence has emerged suggesting that long non-coding RNAs (lncRNAs) play a crucial role in regulating cancer cell function in different types of malignancies, including gastric cancer (GC). However, the specific means by which lncRNAs regulate the function of gastric cancer stem cells (GCSCs) are yet to be fully understood. In this study, we investigated a lncRNA known as HNF1A-AS1, which is highly expressed in GCSC s and serves as a critical regulator of GCSC stemness and tumorigenesis. Our experiments, both in vitro and in vivo, demonstrated that HNF1A-AS1 maintained the stemness of GC cells. Further analysis revealed that HNF1A-AS1, transcriptionally activated by CMYC, functioned as a competing endogenous RNA by binding to miR-150-5p to upregulate β-catenin expression. This in turn facilitated the entry of β-catenin into the nucleus to activate the Wnt/β-catenin pathway and promote CMYC expression, thereby forming a positive feedback loop that sustained the stemness of GCSCs. We also found that blocking the Wnt/β-catenin pathway effectively inhibited the function of HNF1A-AS1, ultimately resulting in the inhibition of GCSC stemness. Taken together, our results demonstrated that HNF1A-AS1 is a regulator of the stemness of GCSCs and could serve as a potential marker for targeted GC therapy.

Prognostic value of CASC15 and LINC01600 as competitive endogenous RNAs in lung adenocarcinoma: An observational study

Long noncoding RNAs (lncRNAs) can directly or indirectly regulate gene expression through interacting with microRNAs (miRNAs). Competitive endogenous RNAs render the roles of lncRNAs more complicated in the process of tumor occurrence and progression. However, the prognostic value of lncRNAs as potential biomarkers and their functional roles as competitive endogenous RNAs have not been clearly described for lung adenocarcinoma (LUAD). In the present study, the aberrant expression profiles of lncRNAs and miRNAs were analyzed at cBioPortal by interrogating LUAD dataset from The Cancer Genome Atlas (TCGA) database with 517 tissue samples. A total of 92 lncRNAs and 125 miRNAs with highly genetic alterations were identified. Further bioinformatics analysis was performed to construct a LUAD-related lncRNA-miRNA-mRNA ceRNA network, which included 24 highly altered lncRNAs, 21 miRNAs and 142 mRNAs. Some key lncRNAs in this network were subsequently identified as LUAD prognosis-related, and of those, CASC15 and LINC01600 both performed the potential prognostic characteristics with LUAD regarding OS and recurrence. Comprehensive analysis indicated that the expression of LINC01600 was significantly associated with KRAS mutation and lymph node metastasis, and CASC15 and LINC01600 were significantly tended towards co-occurrence, which may be due to the similarity of genes co-expressed by these 2 lncRNAs. Our findings provided novel insight into better understanding of ceRNA regulatory mechanisms in the pathogenesis of LUAD and facilitated the identification of potential biomarkers for prognosis.

Colon cancer transcriptome

Over the last four decades, methodological innovations have continuously changed transcriptome profiling. It is now feasible to sequence and quantify the transcriptional outputs of individual cells or thousands of samples using RNA sequencing (RNA-seq). These transcriptomes serve as a connection between cellular behaviors and their underlying molecular mechanisms, such as mutations. This relationship, in the context of cancer, provides a chance to unravel tumor complexity and heterogeneity and uncover novel biomarkers or treatment options. Since colon cancer is one of the most frequent malignancies, its prognosis and diagnosis seem to be critical. The transcriptome technology is developing for an earlier and more accurate diagnosis of cancer which can provide better protectivity and prognostic utility to medical teams and patients. A transcriptome is a whole set of expressed coding and non-coding RNAs in an individual or cell population. The cancer transcriptome includes RNA-based changes. The combined genome and transcriptome of a patient may provide a comprehensive picture of their cancer, and this information is beginning to affect treatment decision-making in real-time. A full assessment of the transcriptome of colon (colorectal) cancer has been assessed in this review paper based on risk factors such as age, obesity, gender, alcohol use, race, and also different stages of cancer, as well as non-coding RNAs like circRNAs, miRNAs, lncRNAs, and siRNAs. Similarly, they have been examined independently in the transcriptome study of colon cancer.

The research progress of Wnt/β-catenin signaling pathway in colorectal cancer

The Wnt/β-catenin signaling pathway is highly conservative. β-catenin is the key molecule in this pathway. The β-catenin target genes regulate cell proliferation and apoptosis. Since Wnt pathway proteins are distributed on the cell membrane, cytoplasm, and nucleus, inhibiting or activating these pathway proteins presents a novel target for cancer treatment via the Wnt signaling pathway. Studies have found that this pathway plays a significant role in the formation and progression of cancers, particularly colorectal cancer. We summarised the activation and inhibition of the Wnt signaling pathway in tumors, its relationship with the microenvironment and crosstalk with other pathways, and the effect of targeting abnormal Wnt signaling in the treatment of colorectal cancer. Here is to review future targeted therapeutics in colorectal cancer research and implementation.

RELA promotes the progression of oral squamous cell carcinoma via TFAP2A-Wnt/β-catenin signaling

Oral squamous cell carcinoma (OSCC) has emerged as the most prevailing oral malignancy worldwide, characterized by cervical solid lymph node metastasis and strong local invasiveness. Overexpression of Transcription Factor AP-2 alpha (TFAP2A) is observed in a significant proportion of OSCC cases. In this study, we aimed to elucidate the function of TFAP2A in the progression of OSCC and the related molecular signaling pathways. The role of RELA was predicted using bioinformatics analysis. The mRNA abundances of RELA, TFAP2A, and β-catenin were assessed by Western blot and quantitative real-timePCR. The relationship between RELA, TFAP2A, and β-catenin and their correlation with clinicopathological characteristics of OSCC was evaluated. The target of RELA and TFAP2A was identified by the chromatin immunoprecipitation as well as luciferase reporter assay. The colony formation assay and MTS assay were performed to determine the proliferative level of OSCC cells. OSCC cell motility was determined by Transwell assay and wound-healing assay. The protein expressions of epithelial-mesenchymal transition-associated factors were evaluated by Western blot. The expressions of RELA and TFAP2A were elevated in OSCC, and their expressions displayed a positive correlation. The expression levels of RELA and TFAP2A were found to be associated with TNM staging and lymphatic metastasis of OSCC patients. RELA upregulation promoted OSCC progression, as manifested by increased levels of proliferation, invasion, and migration of OSCC cells. We also demonstrated that RELA was directly bound to the promoter of TFAP2A transcription, which activated multiple malignant and metastatic phenotypes. Furthermore, TFAP2A activated the Wnt/β-catenin signaling by targeting the promoter regions of β-catenin. The study found that RELA is critical for promoting the progression of OSCC via the RELA-TFAP2A-Wnt/β-catenin signaling pathway. The RELA-TFAP2A-Wnt/β-catenin signaling pathway is a potential target for reducing the aggressiveness of OSCC.

Targeting lncRNA/Wnt axis by flavonoids: A promising therapeutic approach for colorectal cancer

Despite the dramatic advances in our understanding of the etiology of colorectal cancer (CRC) in recent decades, effective therapeutic strategies are still urgently needed. Oncogenic mutations in the Wnt/β-Catenin pathway are hallmarks of CRC. Moreover, long non-coding RNAs (lncRNAs) as molecular managers are involved in the initiation, progression, and metastasis of CRC. Therefore, it is important to further explore the interaction between lncRNAs and Wnt/β-Catenin signaling pathway for targeted therapy of CRC. Natural phytochemicals have not toxicity and can target carcinogenesis-related pathways. Growing evidences suggest that flavonoids are inversely associated with CRC risk. These bioactive compounds could target carcinogenesis pathways of CRC and reduced the side effects of anti-cancer drugs. The review systematically summarized the progress of flavonoids targeting lncRNA/Wnt axis in the investigations of CRC, which will provide a promising therapeutic approach for CRC and develop nutrition-oriented preventive strategies for CRC based on epigenetic mechanisms. In the field, more epidemiological and clinical trials are required in the future to verify feasibility of targeting lncRNA/Wnt axis by flavonoids in the therapy and prevention of CRC.

Regulatory Roles of Noncoding RNAs in the Progression of Gastrointestinal Cancers and Health Disparities

Annually, more than a million individuals are diagnosed with gastrointestinal (GI) cancers worldwide. With the advancements in radio- and chemotherapy and surgery, the survival rates for GI cancer patients have improved in recent years. However, the prognosis for advanced-stage GI cancers remains poor. Site-specific GI cancers share a few common risk factors; however, they are largely distinct in their etiologies and descriptive epidemiologic profiles. A large number of mutations or copy number changes associated with carcinogenesis are commonly found in noncoding DNA regions, which transcribe several noncoding RNAs (ncRNAs) that are implicated to regulate cancer initiation, metastasis, and drug resistance. In this review, we summarize the regulatory functions of ncRNAs in GI cancer development, progression, chemoresistance, and health disparities. We also highlight the potential roles of ncRNAs as therapeutic targets and biomarkers, mainly focusing on their ethnicity-/race-specific prognostic value, and discuss the prospects of genome-wide association studies (GWAS) to investigate the contribution of ncRNAs in GI tumorigenesis.

HNF1A-AS1：A tumor-associated long non-coding RNA

BACKGROUND

Hepatocyte nuclear factor 1 homeobox A antisense RNA 1 (HNF1A-AS1) is a Long non-coding RNA（LncRNA）that participates in the occurrence development of lots of tumors and is supposed to be a new biomarker. The text aims to illustrate the biological effect, specific mechanism and clinical significance of HNF1A-AS1 in various tumors.

METHODS

Via consulting the literature, analyze and summarize the relationship between HNF1A-AS1 and all kinds of tumors and the specific mechanism.

RESULTS

This is a review paper about the tumor-associated long non-coding RNA HNF1A-AS1. Many Researches show that LncRNA HNF1A-AS1 is related to the development of tumorous tumors. Its expression is up-regulated in numerous tumors, such as oral squamous cell carcinoma, hepatocellular carcinoma, breast cancer, osteosarcoma， lung cancer, cervical cancer, bladder cancer, colon cancer, colorectal cancer, oesophageal adenocarcinoma and laryngeal squamous cell carcinoma. However, HNF1A-AS1 is down-regulated in gastroenteropancreatic, neuroendocrine neoplasms, oral squamous cell carcinoma. Furthermore, HNF1A-AS1 can affect tumor proliferation, invasion, migration and apoptosis by targeting some microRNAs-miR-661 and miR-124. Or HNF1A-AS1 can also influence the development of tumors by regulating EMT.

CONCLUSION

These studies show that LncRNA-HNF1A-AS1 is closely related to the occurrence development of numerous cancers. Through various molecular mechanisms to regulate tumor growth, HNF1A-AS1 can possibly become the new biological biomarker and therapeutic target for many kinds of tumors.

Exosomal-long non-coding RNAs journey in colorectal cancer: Evil and goodness faces of key players

Exosomes are nano-vesicles (NVs) secreted by cells and take part in cell-cell communications. Lately, these exosomes were proved to have dual faces in cancer. Actually, they can contribute to carcinogenesis through epithelial-mesenchymal transition (EMT), angiogenesis, metastasis and tumor microenvironment (TME) of various cancers, including colorectal cancer (CRC). On the other hand, they can be potential targets for cancer treatment. CRC is one of the most frequent tumors worldwide, with incidence rates rising in the recent decades. In its early stage, CRC is asymptomatic with poor treatment outcomes. Therefore, finding a non-invasive, early diagnostic biomarker tool and/or suitable defender to combat CRC is mandatory. Exosomes provide enrichment and safe setting for their cargos non-coding RNAs (ncRNAs) and proteins, whose expression levels can be upregulated ordown-regulated in cancer. Hence, exosomes can be used as diagnostic and/or prognostic tools for cancer. Moreover, exosomes can provide a novel potential therapeutic modality for tumors via loading with specific chemotherapeutic agents, with the advantage of possible tumor targeting. In this review, we will try to collect and address recent studies concerned with exosomes and their cargos' implications for CRC diagnosis and/or hopefully, treatment.

Therapeutic strategies targeting Wnt/β‑catenin signaling for colorectal cancer (Review)

Colorectal cancer (CRC) is one of the most common carcinomas. Although great progress has been made in recent years, CRC survival remains unsatisfactory due to high metastasis and recurrence. Understanding the underlying molecular mechanisms of CRC tumorigenesis and metastasis has become increasingly important. Recently, aberrant Wnt/β‑catenin signaling has been reported to be strongly associated with CRC tumorigenesis, metastasis and recurrence. Therefore, the Wnt/β‑catenin signaling pathway has potential value as a therapeutic target for CRC. In the present review, the dysregulation of this pathway in CRC and the promoting or suppressing function of therapeutic targets on CRC were explored. In addition, the interaction between this pathway and epithelial‑mesenchymal transition (EMT), cell stemness, mutations, metastasis‑related genes and tumor angiogenesis in CRC cells were also investigated. Numerous studies on this pathway may help identify the potential diagnostic and prognostic markers and therapeutic targets for CRC.

Association of a novel antisense lncRNA TP73-AS1 polymorphisms and expression with colorectal cancer susceptibility and prognosis

BACKGROUND

TP73-AS1 is a novel antisense long noncoding RNA and plays an important role in cell proliferation and cancer development. However, the link between TP73-AS1 and colorectal cancer (CRC) has not yet been reported.

OBJECTIVE

To explore the association of genetic variants in TP73-AS1 and its expression with CRC susceptibility and prognosis.

METHODS

A case-control study (including 507 CRC cases and 503 controls) and bioinformatics analysis were conducted.

RESULTS

rs9800 polymorphism was significantly related to higher risk in CRC [adjusted odds ratio (AOR) = 1.33, 95% confidence interval (CI) = 1.02-1.75, P = 0.034 in heterozygote codominant model]. There was no difference between TP73-AS1 polymorphisms and different tumor node metastasis (TNM) stages in the adjusted model. Moreover, TP73-AS1 expression level was positively related to different TNM stages. After adjusted for age, gender and TNM, higher TP73-AS1 expression levels were related to shorter recurrence-free survival time [hazard ratio (HR) = 1.66, 95% CI = 1.02-2.71, P = 0.043].

CONCLUSION

TP73-AS1 polymorphisms and expression may be associated with susceptibility and prognosis of CRC.

LINC01559 promotes colorectal cancer via sponging miR-1343-3p to modulate PARP1/PTEN/AKT pathway

BACKGROUND

Colorectal cancer (CRC) is considered as one of the commonest tumors and is the major reason of cancer-related deaths around the world. Plentiful evidences have validated that long non-coding RNAs (lncRNAs) play a significant part in various cancers, including CRC. LINC01559 is implicated in the development of various cancers. However, the detailed function of LINC01559 in CRC has not been illustrated.

METHODS

LINC01559 expression was examined via RT-qPCR, and a series of functional experiments were conducted to explore the role of LINC01559 in CRC progression. Mechanism experiments were carried out to examine the underlying mechanism of LINC01559.

RESULTS

LINC01559 expression was increased in CRC cells and tissues, and LINC01559 depletion restrained the biological behaviors of CRC cells. Also, LINC01559 sponged miR-1343-3p in CRC, and PARP1 was the target of miR-1343-3p. Besides, miR-1343-3p overexpression or PARP1 down-regulation affected the biological behaviors of CRC cells. In addition, up-regulation of PARP1 or adding SC79 (AKT pathway activator) could remedy the repressive effects of LINC01559 silencing on CRC cell biological behaviors.

CONCLUSIONS

LINC01559 promotes CRC through sponging miR-1343-3p to modulate PARP1/PTEN/AKT pathway, which may be conducive to offering a new idea for CRC therapeutic treatment.

TCF-3-mediated transcription of lncRNA HNF1A-AS1 targeting oncostatin M expression inhibits epithelial-mesenchymal transition via TGFβ signaling in gastroenteropancreatic neuroendocrine neoplasms

Long noncoding RNAs play key roles in several cancers, but their potential functions in gastroenteropancreatic neuroendocrine neoplasms remain to be investigated. We performed GeneChip assay to explore differentiated lncRNAs in gastric NENs and peri-cancerous tissues. The regulation of HNF1A-AS1 on biological behavior of GEP-NENs cells and in vivo xenograft model was confirmed by CCK8, colony formation assay, transwell, western blot and qRT-PCR. We next detected the potential transcription factors and the binding sites between them with bioinformatic analysis. qRT-PCR was performed to analyze the exact relationship between them. HNF1A-AS1 expression was decreased in gastric NENs tissues (p < 0.01). Over-expression of HNF1A-AS1 suppressed cellular proliferation, migration and invasion. Knockdown of transcription factor 3 inhibited the expression of HNF1A-AS1 and promoted cellular migration and invasion. Oncostatin M was identified as the downstream target of HNF1A-AS1. Inhibition of transforming growth factor-β activity inhibited HNF1A-AS1/Oncostatin M-mediated epithelial-mesenchymal transition. Our data suggest that transcription factor 3/HNF1A-AS1/Oncostatin M axis inhibits the tumorigenesis and metastasis of gastroenteropancreatic neuroendocrine neoplasms via transforming growth factor-β signaling.

Silencing long non-coding RNA HNF1A-AS1 inhibits growth and resistance to TAM of breast cancer cells via the microRNA-363/SERTAD3 axis

Long non-coding RNAs (lncRNAs) can exert effects on drug resistance of cancer cells. This study investigated the role of lncRNA HNF1A-antisense 1 (HNF1A-AS1) in growth and Tamoxifen (TAM) sensitivity of breast cancer (BC) cells. HNF1A-AS1 expression was promoted in BC cells and tissues. BC cells with HNF1A-AS1 silencing were constructed to detect cell proliferation. TAM resistant cell line with HNF1A-AS1 silencing and parent cell line with overexpressed HNF1A-AS1 were constructed to measure drug resistance. Silencing HNF1A-AS1 reduced proliferation and TAM resistance of BC cells. The downstream microRNAs (miRs) of HNF1A-AS1 and its targets were figured out and their functions in TAM resistance of BC cells were identified. HNF1A-AS1 sponged miR-363 to promote SERTAD3 expression. Downregulation of miR-363 or upregulation of SERTAD3 stimulated TAM resistance of BC cells. The findings in vitro were reproduced in in vivo experiments. It could be concluded that silencing HNF1A-AS1 inhibited growth and drug resistance to TAM of BC cells through the miR-363/SERTAD3 axis and the inactivation of the TGF-β/Smad pathway.

Long non-coding RNAs in colorectal cancer: Novel oncogenic mechanisms and promising clinical applications

Colorectal cancer (CRC) is the third most common malignancy and ranks as the second leading cause of cancer-related deaths worldwide. Despite the improvements in CRC diagnosis and treatment approaches, a considerable proportion of CRC patients still suffers from poor prognosis due to late disease detections and lack of personalized disease managements. Recent evidences have not only provided important molecular insights into their mechanistic behaviors but also indicated that identification of cancer-specific long non-coding RNAs (LncRNAs) could benefit earlier disease detections and improve treatment outcomes in patients suffering from CRC. LncRNAs have raised extensive attentions as they participate in various hallmarks of CRC. The mechanistic evidence gleaned in the recent decade clearly reveals that lncRNAs exert their oncogenic roles by regulating autophagy, epigenetic modifications, enhancing stem phenotype and modifying tumor microenvironment. In view of their pleiotropic functional roles in malignant progression, and their frequently dysregulated expression in CRC patients, they have great potential to be reliable diagnostic and prognostic biomarkers, as well as therapeutic targets for CRC. In the present review, we will focus on the oncogenic roles of lncRNAs and related mechanisms in CRC as well as discuss their clinical potential in the early diagnosis, prognostic prediction and therapeutic translation in patients with this malignancy.

GATA1-Activated HNF1A-AS1 Facilitates the Progression of Triple-Negative Breast Cancer via Sponging miR-32-5p to Upregulate RNF38

Background

Triple-negative breast cancer (TNBC) is a highly invasive subtype of breast cancer with a high mortality rate. Recently, long non-coding RNAs (lncRNAs) are confirmed to modulate the progression of assorted cancers, including TNBC. However, the functions of lncRNA HNF1 homeobox A antisense RNA 1 (HNF1A-AS1) in TNBC are still unclear.

Aim

We aimed to investigate the function and mechanism of HNF1A-AS1 in TNBC.

Methods

The expression of genes in TNBC cells was tested by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. In vitro loss-of-function assays and in vivo xenograft experiments were conducted for evaluating the impact of HNF1A-AS1 on TNBC progression. RNA pull-down, luciferase reporter and RNA immunoprecipitation (RIP) assays were utilized for assessing the correlations between molecules.

Results

We discovered that HNF1A-AS1 was highly expressed in TNBC tissues and cells. Knockdown of HNF1A-AS1 restrained cell proliferation but accelerated cell apoptosis. Besides, GATA-binding protein 1 (GATA1) activated HNF1A-AS1 transcription in TNBC. MicroRNA-32-5p (miR-32-5p) was slowly expressed in TNBC cells and sponged by HNF1A-AS1, and its overexpression hinders TNBC cell growth. Ring finger protein 38 (RNF38) was verified as the target of miR-32-5p, and HNF1A-AS1 was a competing endogenous RNA (ceRNA) of RNF38 through sponging miR-32-5p. Rescue experiments indicated that upregulation of RNF38 reversed the inhibited impacts of silencing HNF1A-AS1 on TNBC cell growth.

Conclusion

GATA1-activated HNF1A-AS1 facilitated TNBC progression via miR-32-5p/RNF38 axis. The findings may provide new roads for developing targeted therapies of TNBC.

LncRNA-SARCC sensitizes osteosarcoma to cisplatin through the miR-143-mediated glycolysis inhibition by targeting Hexokinase 2

Chemotherapy is one of the primary treatments used against cancer. Cisplatin is a conventional chemotherapy drug used to treat osteosarcoma; however, due to the development of cisplatin resistance, advantageous therapeutic outcomes and prognosis of osteosarcoma remain low. Thus, investigation of the specific targeted therapies to circumvent the anti-chemoresistance of osteosarcoma depends on understanding the molecular mechanisms underlying cisplatin resistance. Tumor cells display an increased utilization of glycolysis rather than oxidative phosphorylation. This phenomenon is called the "Warburg effect," which presents a survival advantage for tumor cells, leading to chemoresistance. To date, the molecular mechanism underlying osteosarcoma cisplatin resistance remains to be fully elucidated. In this study, we reported the significant down-regulation of the long noncoding RNA-Suppressing Androgen Receptor in Renal Cell Carcinoma (lncRNA-SARCC) in the cells of osteosarcoma and in the specimens from osteosarcoma patients. Moreover, we observed a negative correlation between the lncRNA-SARCC and cisplatin resistance in the osteosarcoma tissues. Overexpression of the lncRNA-SARCC sensitizes osteosarcoma cells to cisplatin. From microarray analysis, we screened several miRNAs, which are significantly regulated by the lncRNA-SARCC in osteosarcoma cells, and revealed that lncRNA-SARCC promoted microRNA-43 (miR-143) expression in osteosarcoma. Interestingly, miR-143 showed the same expression pattern with the lncRNA-SARCC in osteosarcoma patient specimens. By establishing a cisplatin-resistant cell line from Sarcoma Osteogenic-2 (Saos-2), we found the cisplatin-resistant cells with down-regulated expressions of the lncRNA-SARCC and miR-143, but with a higher glycolysis rate compared to that in parental cells. We identified the glycolysis key enzyme, Hexokinase 2 (HK2), as a direct target for miR-143 in osteosarcoma. Restoration of the HK2 expression in the lncRNA-SARCC-overexpressing osteosarcoma cells reversed cisplatin resistance, suggesting that lncRNA-SARCC-mediated cisplatin sensitivity may be via glycolysis in the miR-143-inhibited osteosarcoma cells. Finally, results from both in vitro and in vivo xenograft models demonstrated that the lncRNA-SARCC was an effective therapeutic agent for overcoming cisplatin resistance in osteosarcoma. Our findings suggest an essential axis of the lncRNA-SARCC-miR-143-HK2 in regulation of osteosarcoma chemosensitivity, presenting the lncRNA-SARCC as a new therapeutic target against cisplatin-resistant osteosarcoma.

Molecular characteristics of primary pulmonary lymphoepithelioma-like carcinoma based on integrated genomic analyses

Primary pulmonary lymphoepithelioma-like carcinoma (pLELC) is a rare non-small cell lung cancer (NSCLC) subtype. Clinical features have been described in our previous report, but molecular characteristics remain unclear. Herein, pLELC genomic features were explored. Among 41,574 lung cancers, 128 pLELCs and 162 non-pLELC NSCLCs were enrolled. Programmed cell death ligand 1 (PD-L1) and protein 53 (p53) expression was detected in 47 surgically resected pLELC samples by immunohistochemical assays. Multiomics genomic analyses, including whole-genome sequencing (WGS), RNA whole-transcriptome sequencing (RNA-seq), and Epstein-Barr virus (EBV) integration analyses, were performed on eight frozen pLELC tissues and compared with 50 lung adenocarcinomas (LUADs) and 50 lung squamous cell carcinomas (LUSCs) from The Cancer Genome Atlas (TCGA) and another 26 EBV-positive nasopharynx cancers (EBV⁺-NPCs). Progression-free survival (PFS) and overall survival (OS) of pLELC patients were better than those of non-pLELC patients. High PD-L1 or p53 expression was associated with extended disease-free survival (DFS). pLELC had 14 frequently mutated genes (FMGs). Somatically mutated genes and enrichment of genetic lesions were found, which differed from observations in LUAD, LUSC, and EBV⁺-nasopharyngeal carcinoma (NPC). Three tumor-associated genes, zinc finger and BTB domain-containing 16 (ZBTB16), peroxisome proliferator activated receptor gamma (PPARG), and transforming growth factor beta receptor 2 (TGFBR2), were downregulated with copy number variation (CNV) loss. EBV was prone to integrating into intergenic and intronic regions with two upregulated miR-BamH1-A rightward transcripts (BARTs), BART5-3P and BART20-3P. Our findings reveal that pLELC has a distinct genomic signature. Three tumor-associated genes with CNV loss and two miR-BARTs might be involved in pLELC tumorigenesis.

REST-repressed lncRNA NPPA-AS1 regulates cervical cancer progression by modulating miR-302e/DKK1/Wnt/β-catenin signaling pathway

Long noncoding RNAs (lncRNAs), a group of transcripts, have been revealed to be critical participants in regulating multiple biological processes of malignant tumors. The knowledge of NPPA-AS1 (a new lncRNA) in cancer research is hardly known. Thus, it is of urgent need to study the underlying role of NPPA antisense RNA 1 (NPPA-AS1) in cervical cancer (CC). In this study, NPPA-AS1 was discovered to be lowly expressed and upregulation of it impaired cell proliferation and migration in CC. Besides, downregulation of it led to opposite results. Molecular mechanism assays uncovered that increased expression of NPPA-AS1 could inactivate Wnt/β-catenin signaling pathway in CC. In addition, NPPA-AS1 was found to negatively interact with miR-302e whereas positively correlate with dickkopf-1 (DKK1, an inhibitor of Wnt pathway) in CC. Besides, loss of function assay illuminated that miR-302e inhibition restrained cell proliferation and migration in CC. Subsequent rescue assays confirmed that NPPA-AS1 acted as a competing endogenous RNA in CC by sponging miR-302e to upregulate DKK1 expression. Finally, the RE-1 silencing transcription factor (REST) was testified to function as a transcription suppressor of NPPA-AS1 in CC. In brief, REST-repressed NPPA-AS1 regulates CC progression by modulating miR-302e/DKK1/Wnt/β-catenin signaling pathway.

Transcriptome analysis uncovers the diagnostic value of miR-192-5p/HNF1A-AS1/VIL1 panel in cervical adenocarcinoma

Despite the fact that the incidence of cervical squamous cell carcinoma has decreased, there is an increase in the incidence of cervical adenocarcinoma. However, our knowledge on cervical adenocarcinoma is largely unclear. Transcriptome sequencing was conducted to compare 4 cervical adenocarcinoma tissue samples with 4 normal cervical tissue samples. mRNA, lncRNA, and miRNA signatures were identified to discriminate cervical adenocarcinoma from normal cervix. The expression of VIL1, HNF1A-AS1, MIR194-2HG, SSTR5-AS1, miR-192-5p, and miR-194-5p in adenocarcinoma were statistically significantly higher than that in normal control samples. The Receiver Operating Characteristic (ROC) curve analysis indicated that combination of miR-192-5p, HNF1A-AS1, and VIL1 yielded a better performance (AUC = 0.911) than any single molecule -and could serve as potential biomarkers for cervical adenocarcinoma. Of note, the combination model also gave better performance than TCT test for cervical adenocarcinoma diagnosis. However, there was no correlation between miR-192-5p or HNF1A-AS1 and HPV16/18 E6 or E7. VIL1 was weakly correlated with HPV18 E7 expression. In summary, our study has identified miR-192-5p/HNF1A-AS1/VIL1 panel that accurately discriminates adenocarcinoma from normal cervix. Detection of this panel may provide considerable clinical value in the diagnosis of cervical adenocarcinoma.

Long Noncoding RNA HNF1A-AS1 Regulates Osteosarcoma Advancement Through Modulating the miR-32-5p/HMGB1 Axis

Background: Osteosarcoma (OS) is a primary malignant tumor in children and adolescents. Long noncoding RNA HNF1A antisense RNA 1 (HNF1A-AS1) is connected with OS development. However, there are few reports on the role and mechanism of HNF1A-AS1 in OS. Materials and Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to assess the expression of HNF1A-AS1, miR-32-5p, and high-mobility group protein B1 (HMGB1). Western blot analysis was performed to detect the protein level of HMGB1. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, transwell, or flow cytometer assays were applied to determine the proliferation, migration, invasion, and apoptosis of OS cells. The interaction between HNF1A-AS1 and miR-32-5p or HMGB1 was predicted by the starBase database and confirmed by dual-luciferase reporter assay. Enzyme-linked immunosorbent assay was employed to analyze levels of HMGB1 in the OS cell supernatant. Results: HNF1A-AS1 and HMGB1 were upregulated, while miR-32-5p was downregulated, in OS tissues and cells. Functionally, HNF1A-AS1 depletion induced apoptosis and impeded proliferation, migration, and invasion of OS cells. Interestingly, HNF1A-AS1 bound to miR-32-5p to regulate the expression of HMGB1. Furthermore, miR-32-5p knockdown overturned the effects of HNF1A-AS1 knockdown on apoptosis, proliferation, migration, and invasion of OS cells. In addition, the effects of HNF1A-AS1 silencing on the malignant behaviors of OS cells were reserved by HMGB1 overexpression. In addition, HNF1A-AS1 regulated the HMGB1 level in the OS cell supernatant through the miR-32-5p/HMGB1 axis. Conclusion: Downregulation of HNF1A-AS1 blocked OS progression through the miR-32-5p/HMGB1 axis, which provides a possible target and prognostic biomarker for treatment of OS.

MYC-activated lncRNA HNF1A-AS1 overexpression facilitates glioma progression via cooperating with miR-32-5p/SOX4 axis

Mounting literatures have revealed the crucial effects of long noncoding RNA (lncRNA) in various cancers, including glioma. HNF1A‐AS1, a novel lncRNA, is reported to modulate tumorigenesis and development of multiple cancers. However, the tumorigenic function of lncRNA HNF1A‐AS1 in glioma remains largely unknown. quantitative reverse transcription and polymerase chain reaction and western blot assays were applied to evaluate the expression of relevant mRNAs and proteins. 5‐Ethynyl‐2’‐ deoxyuridine, terminal deoxynucleotidyl transferase dUTP nick‐end labeling, flow cytometry, and transwell assays were conducted for examining the influence of HNF1A‐AS1 on glioma cell functions. The relationship among RNAs was investigated by mechanical experiments. The results demonstrated that HNF1A‐AS1 was predominantly highly expressed in glioma cell lines compared with nontumor glial epithelial cell, which was associated with the stimulation of transcription factor myelocytomatosis oncogene. Knockdown of HNF1A‐AS1 remarkably inhibited glioma cells proliferation, migration, and invasion, while accelerating cell apoptosis in vitro. Mechanically, HNF1A‐AS1 served as a miR‐32‐5p sponge. Moreover, SOX4 was discovered as a target of miR‐32‐5p. Inhibited miR‐32‐5p or upregulated SOX4 could markedly counteract the inhibitory effects of silencing HNF1A‐AS1 on glioma malignant biological behaviors. HNF1A‐AS1 exerted oncogenic property in glioma progression via upregulating miR‐32‐5p–mediated SOX4 expression, suggesting potential novel therapeutic target for future glioma treatment.

The Roles of Long Noncoding RNAs HNF1α-AS1 and HNF4α-AS1 in Drug Metabolism and Human Diseases

Long noncoding RNAs (lncRNAs) are RNAs with a length of over 200 nucleotides that do not have protein-coding abilities. Recent studies suggest that lncRNAs are highly involved in physiological functions and diseases. lncRNAs HNF1α-AS1 and HNF4α-AS1 are transcripts of lncRNA genes HNF1α-AS1 and HNF4α-AS1, which are antisense lncRNA genes located in the neighborhood regions of the transcription factor (TF) genes HNF1α and HNF4α, respectively. HNF1α-AS1 and HNF4α-AS1 have been reported to be involved in several important functions in human physiological activities and diseases. In the liver, HNF1α-AS1 and HNF4α-AS1 regulate the expression and function of several drug-metabolizing cytochrome P450 (P450) enzymes, which also further impact P450-mediated drug metabolism and drug toxicity. In addition, HNF1α-AS1 and HNF4α-AS1 also play important roles in the tumorigenesis, progression, invasion, and treatment outcome of several cancers. Through interacting with different molecules, including miRNAs and proteins, HNF1α-AS1 and HNF4α-AS1 can regulate their target genes in several different mechanisms including miRNA sponge, decoy, or scaffold. The purpose of the current review is to summarize the identified functions and mechanisms of HNF1α-AS1 and HNF4α-AS1 and to discuss the future directions of research of these two lncRNAs.

Activator of thyroid and retinoid receptor increases sorafenib resistance in hepatocellular carcinoma by facilitating the Warburg effect

Sorafenib resistance is a major challenge in the therapy for advanced hepatocellular carcinoma (HCC). However, the underlying molecular mechanisms of HCC resistance to sorafenib remain unclear. Activator of thyroid and retinoid receptor (ACTR, also known as SRC‐3), overexpressed in HCC patients, plays an important oncogenic role in HCC; however, the link between ACTR and sorafenib resistance in HCC is unknown. Our study demonstrated that ACTR was one of the most upregulated genes in sorafenib‐resistant HCC xenografts. ACTR increases sorafenib resistance through regulation of the Warburg effect. ACTR promotes glycolysis through upregulation of glucose uptake, ATP and lactate production, and reduction of the extracellular acidification and the oxygen consumption rates. Glycolysis regulated by ACTR is vital for the susceptibility of HCC to sorafenib in vitro and in vivo. Mechanistically, ACTR knockout or knockdown decreases the expression of glycolytic enzymes. In HCC patients, ACTR expression is positively correlated with glycolytic gene expression and is associated with poorer outcome. Furthermore, ACTR interacts with the central regulator of the Warburg effect, c‐Myc, and promotes its recruitment to glycolytic gene promoters. Our findings provide new clues regarding the role of ACTR as a prospective sensitizing target for sorafenib therapy in HCC.

Deletion of HNF1A-AS1 Suppresses the Malignant Phenotypes of Breast Cancer Cells In Vitro and In Vivo Through Targeting miRNA-20a-5p/TRIM32 Axis

Background: Hepatocyte nuclear factor 1 homeobox A-antisense RNA 1 (HNF1A-AS1) is a long noncoding RNA and controls human tumor development and progression. However, its expression and role in breast cancer, the most overwhelmingly occurring malignancy in women globally, remain poorly illuminated. Materials and Methods: Expression of HNF1A-AS1, miRNA (miR)-20a-5p, and tripartite motif containing 32 (TRIM32) was detected using quantitative real-time polymerase chain reaction and Western blotting. Cell proliferation, apoptosis, migration, and invasion were measured by cellTiter 96 AQueous one solution cell proliferation assay kit, flow cytometry, and transwell assays, respectively. Epithelial-mesenchymal transition (EMT) was evaluated by Western blotting, analyzing E-cadherin, N-cadherin, and vimentin expression. Mice xenograft model was generated to investigate tumor growth in vivo. The target binding among miR-20a-5p, HNF1A-AS1, and TRIM32 was confirmed by dual-luciferase reporter assay. Results: Expression of HNF1A-AS1 and TRIM32 was upregulated and miR-20a-5p was downregulated in breast cancer tumors and cell lines. Deletion of HNF1A-AS1 induced cell apoptosis rate, but suppressed cell proliferation, EMT, migration, and invasion in MDA-MB-231 and MCF-7 cells. Furthermore, HNF1A-AS1 downregulation impeded tumor growth in vivo. Interestingly, miR-20a-5p overexpression elicited the similar suppressive effects in MDA-MB-231 and MCF-7 cells, which was partially reversed by TRIM32 upregulation; besides, miR-20a-5p silencing could abolish the antitumor role of HNF1A-AS1 deletion. Notably, HNF1A-AS1 positively modulated TRIM32 expression through acting as a molecular "sponge" for miR-20a-5p. Conclusions: Knockdown of HNF1A-AS1 suppressed breast carcinogenesis presumably through targeting miR-20a-5p/TRIM32 axis, suggesting that HNF1A-AS1 might be a promising therapy target for breast cancer.

Long non-coding RNA HANR as a biomarker for the diagnosis and prognosis of colorectal cancer

Previous work suggests that the long noncoding RNA HCC associated long non-coding RNA (HANR) is associated with hepatocellular carcinoma (HCC) progression, but its significance in the context of colorectal cancer (CRC) remains to be determined. Therefore, in this study we assessed the prognostic and diagnostic value of HANR in patients suffering from CRC.The HANR expression in 165 pairs of CRC cancer and adjacent non-cancerous prostate tissues was measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. Student t test was conducted for intergroup comparison. Pearson correlation test was used for correlation analysis. Survival curves were carried out by the Kaplan-Meier method and evaluated using the log-rank test. Multivariable Cox proportional hazard risk regression model was performed to screen the independent factor affected the prognosis of CRC patients.In this study, levels of HANR were significantly higher in CRC tumor samples relative to adjacent normal tissue samples (P < .001). A ROC analysis suggested HANR expression could be reliably used to differentiate between normal and CRC tumor tissue. In addition, elevated HANR expression was positively correlated with more advanced and aggressive CRC features, such as a larger tumor size (P = .003), increased invasion depth (P = .012), and more advanced TNM stage (P = .011). Survival analyses revealed that elevated HANR expression was correlated with worse overall survival (P = .002) and disease-free survival (P = .003). A multivariate analysis further confirmed the relevance of HANR as an independent predictor of CRC patient outcomes.In summary, these results indicate that the lncRNA HANR is a promising prognostic indicator in CRC patients.

Prognostic and clinical significance of long non-coding RNA HNF1A-AS1 in solid cancers: A systematic review and meta-analysis

BACKGROUND

LncRNA HNF1A Antisense RNA 1 (HNF1A-AS1) is often dysregulated in cancer. We performed this meta-analysis to clarify the usefulness of HNF1A-AS1 as a prognostic marker in malignant tumors.

METHODS

The PubMed, OVID, and Web of Science databases were searched from inception to January 11, 2018. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to explore the relationship between HNF1A-AS1 expression and survival. Odds ratios (OR) were calculated to assess the association between HNF1A-AS1 expression and pathological parameters.

RESULTS

Eight studies with a total of 802 patients were included in the study. The pooled hazard ratio (HR) suggested high HNF1A-AS1 expression correlated with poor overall survival (OS) (HR = 4.85, 95% confidence interval (CI): 2.43-9.68), and disease-free survival (DFS) (HR = 6.34, 95% CI: 1.03-39.12) in cancer patients. High HNF1A-AS1 expression also correlated with poor histological grade (OR = 1.88, 95% CI: 1.27-2.79), high tumor stage (OR = 4.04, 95% CI: 2.53-6.47), lymph node metastasis (LNM) (OR = 4.53, 95% CI: 2.30-8.92), and distant metastasis (OR = 5.99, 95% CI: 2.88-12.48). Begg funnel plot did not show any evidence of obvious asymmetry for high tumor stage (Pr > |z| = 0.368) and LNM (Pr > |z| = 1.000).

CONCLUSIONS

Thus high HNF1A-AS1 expression is predictive of poor OS, DFS, lymph node metastasis, distant metastasis, histological grade, and larger tumor stage, which suggests high HNF1A-AS1 expression may serve as a novel biomarker of poor prognosis in cancer.

LINC00365 promotes colorectal cancer cell progression through the Wnt/β-catenin signaling pathway

In the past decade, substantial evidence established that long noncoding RNAs are serious about mediating the evolution of malignancies. In previous studies, LINC00365, which has not been reported in colorectal cancer (CRC), was selected using the bioinformatics analysis in GSE109454 and GSE41655 data sets. However, the function and mechanism of LINC00365 are still obscure. In our study, LINC00365 was found upregulated in CRC specimens and intimately connected with the prognosis of patients with CRC. In addition, LINC00365 overexpression enhances the cell abilities of proliferation, migration, and invasion in vitro. Meanwhile, mechanistic studies showed that LINC00365 might involve in CRC cell progression by mediating the Wnt/β-catenin pathway. Furthermore, LINC00365 upregulation increased CDK1 protein expression. In conclusion, this study suggests that LINC00365 acts as a vital part in facilitating CRC progression and might play as a therapeutic target for patients with CRC.

Regulation Mechanism of Long Noncoding RNAs in Colon Cancer Development and Progression

Colorectal cancer (CRC) is the second most common cause of cancer-related death worldwide, and its high rates of relapse and metastasis are associated with a poor prognosis. Despite extensive research, the underlying regulatory mechanisms of CRC remain unclear. Long noncoding RNAs (lncRNAs) are a major type of noncoding RNAs that have received increasing attention in the past few years, and studies have shown that they play a role in many biological processes in CRC. Here, we summarize recent studies on lncRNAs associated with CRC and the signaling pathways and mechanisms underlying this association. We show that dysregulated lncRNAs may be new prognostic and diagnostic biomarkers or therapeutic targets for clinical application. This review contributes not only to our understanding of CRC, but also suggests novel signaling pathways associated with lncRNAs that can be targeted to block or eradicate CRC.

The HNF1α-Regulated LncRNA HNF1α-AS1 Is Involved in the Regulation of Cytochrome P450 Expression in Human Liver Tissues and Huh7 Cells

Expression of cytochrome P450s (P450s) is regulated by epigenetic factors, such as DNA methylation, histone modifications, and noncoding RNAs through different mechanisms. Among these factors, long noncoding RNAs (lncRNAs) have been shown to play important roles in the regulation of gene expression; however, little is known about the effects of lncRNAs on the regulation of P450 expression. The aim of this study was to explore the role of lncRNAs in the regulation of P450 expression by using human liver tissues and hepatoma Huh7 cells. Through lncRNA microarray analysis and quantitative polymerase chain reaction in human liver tissues, we found that the lncRNA hepatocyte nuclear factor 1 alpha antisense 1 (HNF1α-AS1), an antisense RNA of HNF1α, is positively correlated with the mRNA expression of CYP2C8, 2C9, 2C19, 2D6, 2E1, and 3A4 as well as pregnane X receptor (PXR) and constitutive androstane receptor (CAR). Gain- and loss-of-function studies in Huh7 cells transfected with small interfering RNAs or overexpression plasmids showed that HNF1α not only regulated the expression of HNF1α-AS1 and P450s, but also regulated the expression of CAR, PXR, and aryl hydrocarbon receptor (AhR). In turn, HNF1α-AS1 regulated the expression of PXR and most P450s without affecting the expression of HNF1α, AhR, and CAR. Moreover, the rifampicin-induced expression of P450s was also affected by HNF1α and HNF1α-AS1. In summary, the results of this study suggested that HNF1α-AS1 is involved in the HNF1α-mediated regulation of P450s in the liver at both basal and drug-induced levels.

STAT3-induced upregulation of long noncoding RNA HNF1A-AS1 promotes the progression of oral squamous cell carcinoma via activating Notch signaling pathway

Long non-coding RNAs (lncRNAs) are a group of biomarkers which can regulate the biological processes of various human cancers. LncRNA HNF1A-AS1 has been reported in human cancers for its oncogenic role. This study focused on the biological function and molecular mechanism of HNF1A-AS1 in oral squamous cell carcinoma (OSCC). The high expression of HNF1A-AS1 was examined in OSCC tissues and cell lines. Kaplan Meier method revealed that high expression of HNF1A-AS1 predicted poor prognosis for patients with OSCC. Results of loss-of-function assays demonstrated that silenced HNF1A-AS1 inhibited the proliferation, migration and epithelial-mesenchymal transition (EMT) of OSCC cells. Mechanically, HNF1A-AS1 was positively regulated by the transcription factor STAT3. Recently, Notch signaling pathway has been reported in human malignancies. In this study, we analyzed the correlation between HNF1A-AS1 and Notch signaling pathway. It was uncovered that the expression of Notch1 and Hes1 (the core factors of Notch signaling pathway) was negatively regulated by HNF1A-AS1 knockdown. Rescue assays further demonstrated the positive regulatory effects of HNF1A-AS1 on Notch signaling pathway in OSCC. In conclusion, upregulation of HNF1A-SA1 induced by transcription factor STAT3 promotes OSCC progression by activating Notch signaling pathway.

The roles of Wnt/β-catenin signaling pathway related lncRNAs in cancer

Long noncoding RNAs (lncRNAs), with length of more than 200 nucleotides, are not translated into proteins but involved in multiple diverse diseases, especially tumorigenesis. The dysregulation of lncRNAs greatly contributes to the progression of various tumors through specific signaling pathways, including Wnt/β-catenin signaling pathway, which is associated with malignant features of tumors. The interactions between lncRNAs, which have specific expression characteristics in diverse cancer tissues, and Wnt/β-catenin signaling pathway, exhibit potential as novel biomarkers and therapeutic targets. In this review, we aim to present research findings on the roles of Wnt pathway-related lncRNAs and their effects on Wnt/β-catenin signaling to regulate tumorigenesis in different cancer types. Results may be used as basis to develop or improve strategies for treatment of different carcinomas.

Long non-coding RNA NEAT1 promotes colorectal cancer progression by competitively binding miR-34a with SIRT1 and enhancing the Wnt/β-catenin signaling pathway

In recent years, accumulating evidence has indicated that long non-coding RNAs (lncRNAs) are powerful factors influencing the progression of multiple malignancies. Although a relationship between the lncRNA NEAT1 (nuclear enriched abundant transcript 1) and colorectal cancer has previously been reported, the functional mechanism underlying the involvement of NEAT1 in colorectal cancer remains unknown. In this study, we report that NEAT1 expression is up-regulated in colorectal cancer tissues, which correlates with advanced clinical features, poor overall survival and disease free survival. Up-regulated NEAT1 promotes cell proliferation and metastasis of colorectal cancer both in vitro and in vivo. Moreover, NEAT1 functions as an oncogene influencing cell viability and invasion in part by serving as a competing endogenous RNA (ceRNAs) modulating miRNA-34a expression, leading to subsequent repression of the miR-34a/SIRT1 axis and activation of the Wnt/β-catenin signaling pathway. Taken together, our study demonstrates that the lncRNA NEAT1 may serve as a prognostic biomarker and a potential therapeutic target in colorectal cancer.

Long noncoding RNA DGCR5 represses hepatocellular carcinoma progression by inactivating Wnt signaling pathway

Increasing studies have indicated that long noncoding RNAs (lncRNAs) exert important roles in hepatocellular carcinoma (HCC). Therefore, it is of great significance to identify the dysregulated lncRNAs in HCC. According to the previous reports, it has been suggested that DiGeorge syndrome critical region gene 5 (DGCR5) might participate in HCC and can serve as potential biomarker for HCC. In our current study, we concentrated on the biological function and roles of lncRNA-DGCR5 in HCC. It was indicated that DGCR5 was decreased in HCC tissues and HCC cells including HepG2, Hep3B, MHCC-97L, SNU-449, and SNU-182 cells compared with the normal human liver cell line LO2. Overexpression of DGCR5 was able to restrain HCC growth, migration, and invasion capacity in HepG2 and SNU-449 cells. In addition, whether lncRNA-DGCR5 can regulate Wnt/β-catenin pathway during HCC progression is unclear. In our study, it was found that upregulation of DGCR5 inactivated Wnt signaling pathway through inhibiting β-catenin, cyclin D1 and increasing GSK-3β levels. Subsequently, in vivo tumor xenografts were established using HepG2 cells to investigate the function of DGCR5 in HCC development. Inconsistent with the in vitro findings, increase of DGCR5 dramatically suppressed HCC tumor progression in vivo. Taken these together, it was uncovered in our research that DGCR5 could play tumor suppressive role by targeting Wnt signaling in HCC progression.

EGR1-Mediated Transcription of lncRNA-HNF1A-AS1 Promotes Cell-Cycle Progression in Gastric Cancer

Long noncoding RNAs (lncRNA) are dysregulated in various human cancers and control tumor development and progression. However, the upstream mechanisms underlying their dysregulation remain unclear. Here, we demonstrate that the expression of hepatocyte nuclear factor 1 homeobox A antisense RNA 1 (HNF1A-AS1) is significantly upregulated in gastric cancer tissues. Overexpression of HNF1A-AS1 enhanced cell proliferation and promoted cell-cycle progression, whereas knockdown of HNF1A-AS1 elicited the opposite effects. Early growth response protein 1 (EGR1) directly bound the HNF1A-AS1 promoter region and activated its transcription. Overexpression of EGR1 enhanced cell proliferation and promoted cell-cycle promotion, similar to the function of HNF1A-AS1. HNF1A-AS1 functioned as competing endogenous RNA (ceRNA) by binding to miR-661, upregulating the expression of cell division cycle 34 (CDC34), which is a direct target of miR-661. EGR1 and HNF1A-AS1 enhanced the expression of cyclin-dependent kinase 2 (CDK2), CDK4, and cyclin E1 but inhibited the expression of p21 by promoting CDC34-mediated ubiquitination and degradation of p21. Taken together, these findings suggest that EGR1-activated HNF1A-AS1 regulates various pro- and antigrowth factors to promote the development of gastric cancer, implicating it as a possible target for therapeutic intervention in this disease.Significance: This study provides novel insights into mechanisms by which the noncoding RNA HNF1A-AS1 contributes to gastric cancer progression through modulation of the cell cycle. Cancer Res; 78(20); 5877-90. ©2018 AACR.

Prognostic role of long non-coding RNA HNF1A-AS1 in Chinese cancer patients: a meta-analysis

Background

Long non-coding RNAs (LncRNAs) play important roles in tumorigenesis and progression. Recent studies have demonstrated that LncRNA HNF1A antisense RNA 1 (HNF1A-AS1) is aberrantly expressed in several types of cancers and is associated with poor outcomes. This meta-analysis was conducted to investigate the relationship between HNF1A-AS1 expression and clinical outcomes in cancer patients.

Methods

We searched PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wan Fang databases (updated until December 31, 2017) for literature. A total of eight studies with 789 cancer patients were finally included in the present meta-analysis.

Results

The results showed that high expression of HNF1A-AS1 significantly predicted poor overall survival (HR=3.10, 95% CI: 1.58-6.11, P=0.001), which was further validated using The Cancer Genome Atlas (TCGA) dataset. Moreover, high HNF1A-AS1 expression was also associated with advanced TNM stage (OR=3.32, 95% CI: 2.28-4.83, P<0.001), lymph node metastasis (OR=3.08, 95% CI: 1.95-4.85, P<0.001), and distant metastasis (OR=5.53, 95% CI: 1.94-15.77, P=0.001).

Conclusion

Our results suggested that elevated HNF1A-AS1 was associated with poor clinical outcomes and might serve as a potential prognostic biomarker of cancer.

A Transcriptional Regulatory Network Containing Nuclear Receptors and Long Noncoding RNAs Controls Basal and Drug-Induced Expression of Cytochrome P450s in HepaRG Cells

Cytochrome P450 (P450) enzymes are responsible for metabolizing drugs. Expression of P450s can directly affect drug metabolism, resulting in various outcomes in therapeutic efficacy and adverse effects. Several nuclear receptors are transcription factors that can regulate expression of P450s at both basal and drug-induced levels. Some long noncoding RNAs (lncRNAs) near a transcription factor are found to participate in the regulatory functions of the transcription factors. The aim of this study is to determine whether there is a transcriptional regulatory network containing nuclear receptors and lncRNAs controlling both basal and drug-induced expression of P450s in HepaRG cells. Small interfering RNAs or small hairpin RNAs were applied to knock down four nuclear receptors [hepatocyte nuclear factor 1α (HNF1α), hepatocyte nuclear factor 4α (HNF4α), pregnane X receptor (PXR), and constitutive androstane receptor (CAR)] as well as two lncRNAs [HNF1α antisense RNA 1 (HNF1α-AS1) and HNF4α antisense RNA 1 (HNF4α-AS1)] in HepaRG cells with or without treatment of phenobarbital or rifampicin. Expression of eight P450 enzymes was examined in both basal and drug-induced levels. CAR and PXR mainly regulated expression of specific P450s. HNF1α and HNF4α affected expression of a wide range of P450s as well as other transcription factors. HNF1α and HNF4α controlled the expression of their neighborhood lncRNAs, HNF1α-AS1 and HNF4α-AS1, respectively. HNF1α-AS1 and HNF4α-AS1 was also involved in the regulation of P450s and transcription factors in diverse manners. Altogether, our study concludes that a transcription regulatory network containing the nuclear receptors and lncRNAs controls both basal and drug-induced expression of P450s in HepaRG cells.

MiR-320d suppresses the progression of breast cancervialncRNA HNF1A-AS1 regulation and SOX4 inhibition

MicroRNA-320d (miR-320d) is a novel cancer-related miRNA and functions as a tumor suppressor in human cancers.