Long non-coding RNA HOXD-AS1 promotes tumor progression and predicts poor prognosis in colorectal cancer

The value of exosome-derived noncoding RNAs in colorectal cancer proliferation, metastasis, and clinical applications

Colorectal cancer (CRC) is the third most common cancer in the world today, and its incidence and mortality rates are increasing every year. The ease of proliferation and metastasis of CRC has long been an important reason for its high mortality rate. Exosomes serve as key mediators that mediate communication between tumor cells and various other cells. Non-coding RNAs (ncRNAs) have been shown to play a key role in apoptosis, immunosuppression and proliferation metastasis in cancer. ncRNAs are loaded on exosomes and initiate the onset of metastasis by promoting epithelial-mesenchymal transition (EMT) at the primary site of the tumor. Meanwhile, exosome-derived ncRNAs construct a pre-metastatic niche (PMN) for CRC metastasis by forming an inflammatory microenvironment in distant organs, immunosuppression, and promoting angiogenesis and remodeling of the extracellular matrix. Here, we summarize the specific mechanisms associated with exosome-derived ncRNAs promoting local invasion and metastasis in CRC. Finally, we focus on their value for clinical application in future CRC diagnosis and treatment.

LncRNAs, the Molecules Involved in Communications With Colorectal Cancer Stem Cells

Colorectal cancer stem cells (CRCSCs) can actively self-renew, as well as having multidirectional differentiation and tumor regeneration abilities. Because the high functional activities of CRCSCs are associated with low cure rates in patients with colorectal cancer, efforts have sought to determine the function and regulatory mechanisms of CRCSCs. To date, however, the potential regulatory mechanisms of CRCSCs remain incompletely understood. Many non-coding genes are involved in tumor invasion and spread through their regulation of CRCSCs, with long non-coding RNAs (lncRNAs) being important non-coding RNAs. LncRNAs may be involved in the colorectal cancer development and drug resistance through their regulation of CRCSCs. This review systematically evaluates the latest research on the ability of lncRNAs to regulate CRCSC signaling pathways and the involvement of these lncRNAs in colorectal cancer promotion and suppression. The regulatory network of lncRNAs in the CRCSC signaling pathway has been determined. Further analysis of the potential clinical applications of lncRNAs as novel clinical diagnostic and prognostic biomarkers and therapeutic targets for colorectal cancer may provide new ideas and protocols for the prevention and treatment of colorectal cancer.

A Novel Autophagy-Related lncRNA Prognostic Signature Associated with Immune Microenvironment and Survival Outcomes of Gastric Cancer Patients

Purpose

Autophagy plays a crucial role in the initiation and progression of gastric cancer (GC). However, the role of autophagy-related lncRNAs in GC remains unknown. This study aimed to investigate the prognostic value of the autophagy-related lncRNA signature and its role in the tumor immune microenvironment (TIME) of GC.

Methods

RNA-sequencing (RNA-seq) and clinical data of GC patients were extracted from The Cancer Genome Atlas (TCGA) database. Univariate and multivariate Cox regression analyses were performed to identify the autophagy-related lncRNA prognostic signature which was validated in the test set and entire set. The survival and predictive performance were analyzed based on the Kaplan–Meier and ROC curves. Furthermore, the CIBERSORT algorithm was applied to explore the relationship between this signature and the immune cell infiltration. To elucidate the potential functions of autophagy-related lncRNAs in GC, we constructed the lncRNA-mRNA co-expression network and performed enrichment analysis. Principal component analysis (PCA) and Gene Set Enrichment Analysis (GSEA) were further performed to compare the different statuses between the high-risk and low-risk groups.

Results

We identified 5 autophagy-related lncRNAs (AL355574.1, AC010768.2, AP000695.2, AC087286.2, and HAGLR) to construct a prognostic signature. This signature could be an independent prognostic indicator for GC patients and had a higher prediction efficiency than other clinicopathological parameters. Furthermore, patients in the high-risk score group had a stronger immunosuppressive microenvironment than the low-risk group. The enrichment analysis for mRNAs co-expressed with these lncRNAs indicated that autophagy-related signaling pathways were remarkably enriched. PCA and GSEA further revealed different autophagy and immune statuses in the high- and low-risk groups.

Conclusion

The 5 autophagy-related lncRNA signature has significant clinical implications in prognosis prediction of GC. Meanwhile, our study elucidates the critical role of the autophagy-related lncRNA signature in the TIME of GC.

lncRNA SNHG4 modulates colorectal cancer cell cycle and cell proliferation through regulating miR-590-3p/CDK1 axis

Colorectal cancer (CRC) is a prevalent malignancy worldwide. The development of genome sequencing technology has allowed the discovery that epigenetic regulation might play a critical role in CRC tumorigenesis. In the present study, we found that the long noncoding RNA (lncRNA) SNHG4 was dramatically increased in CRC tissue samples and cell lines based on both publicly available and experimental data. SNHG4 knockdown suppressed the viability and colony formation capacity of CRC cells. The expression of CDK1 was considerably increased in CRC tissue samples and cells and had a positive correlation with the expression of SNHG4 in CRC. SNHG4 silencing not only caused S phase cell cycle arrest but also significantly downregulated the CDK1, cyclin B1, and cyclin A2 protein levels in CRC cells. miR-590-3p simultaneously bound to SNHG4 and CDK1. miR-590-3p functioned to inhibit CDK1 expression. miR-590-3p overexpression exerted the same effects on the CRC cell phenotype as SNHG4 knockdown. The effects of si-SNHG4 on CRC cells were significantly reversed by anti-miR-590-3p, indicating that SNHG4 relieved the miR-590-3p-induced inhibition of CDK1 by acting as a competing endogenous RNA (ceRNA). In vivo, SNHG4 silencing inhibited subcutaneously transplanted tumor growth and decreased cell cycle marker levels, whereas miR-590-3p inhibition exerted the opposite effects. The in vivo effects of SNHG4 silencing were also reversed by miR-590-3p inhibition. The SNHG4/miR-590-3p/CDK1 axis influences the cell cycle to modulate CRC cell proliferation and subcutaneously transplanted tumor growth. Further application of this axis still requires analysis using more animal models and clinical investigations.

The Emerging Landscape of Long Non-Coding RNAs in Colorectal Cancer Metastasis

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers, with extremely high rates of morbidity and mortality. The main cause of death in CRC is distant metastasis; it affects patient prognosis and survival and is one of the key challenges in the treatment of CRC. Long non-coding RNAs (lncRNAs) are a group of non-coding RNA molecules with more than 200 nucleotides. Abnormal lncRNA expression is closely related to the occurrence and progression of several diseases, including cancer. Recent studies have shown that numerous lncRNAs play pivotal roles in the CRC metastasis, and reversing the expression of these lncRNAs through artificial means can reduce the malignant phenotype of metastatic CRC to some extent. This review summarizes the major mechanisms of lncRNAs in CRC metastasis and proposes lncRNAs as potential therapeutic targets for CRC and molecular markers for early diagnosis.

The long noncoding RNA LINC01140/miR-140-5p/FGF9 axis modulates bladder cancer cell aggressiveness and macrophage M2 polarization

MIBC (muscle invasive bladder cancer) only accounts for only a minority of bladder cancers, however, the disease-specific and overall survival rates of patients with MIBC are low. Macrophage M2 polarization has been reported to be associated with poorer prognosis in bladder cancer. Through cancer bioinformatics and experimental analyses, FGF9 was found to be upregulated in MIBC tissues. FGF9 knockdown in T24 cells strongly suppressed the viability, migratory capacity, and invasive capacity of cells; culture with medium from FGF9 knockdown T24 cells (si-FGF9-CM) significantly inhibited macrophage M2 polarization, while promoting M1 polarization. The long noncoding RNA (lncRNA) LINC01140 was positively correlated with FGF9 and was significantly upregulated in MIBC tissues. LINC01140 knockdown inhibited the viability, migratory capacity and invasive capacity of T24 cells; culture in si-LINC01140-CM also inhibited macrophage M2 polarization, while promoting M1 polarization. LINC01140 targeted miR-140-5p, while miR-140-5p targeted FGF9 to form a lncRNA-miRNA-mRNA axis. The effects of miR-140-5p inhibition on bladder cancer aggressiveness and macrophage M2 polarization were opposite to those of LINC01140 or FGF9 knockdown; additionally, miR-140-5p inhibition partially reversed the effects of LINC01140 knockdown on FGF9 protein levels, bladder cancer phenotype, and macrophage M2 polarization. In conclusion, LINC01140, miR-140-5p, and FGF9 form a lncRNA-miRNA-mRNA axis that modulates the bladder cancer phenotype, affects macrophage M2 polarization through the tumor microenvironment, and in turn affects bladder cancer cell aggressiveness.

Long non-coding RNA DIO3OS/let-7d/NF-κB2 axis regulates cells proliferation and metastasis of thyroid cancer cells

Due to the steadily rising morbidity and mortality, thyroid cancer remains the most commonly seen endocrine cancer. The present study attempted to investigate the mechanism from the perspective of long non-coding RNA (lncRNA) regulation. We identified 53 markedly increased lncRNAs in thyroid cancer samples according to TCGA data. Among them, high lncRNA DIO3OS expression was a risk factor for thyroid cancer patients' poorer overall survival. DIO3OS showed to be considerably increased within thyroid cancer tissue samples and cells. Knocking down DIO3OS within thyroid carcinoma cells suppressed cancer cell viability, the capacity of DNA synthesis, cell invasion, as well as cell migration; besides, proliferating markers, ki-67 and PCNA, were decreased by DIO3OS knockdown. Cancer bioinformatics analysis suggested that NF-κB2 might be related to DIO3OS function in thyroid cancer carcinogenesis. NF-κB2 was positively correlated with DIO3OS, and DIO3OS knockdown decreased NF-κB2 protein levels. Knocking down NF-κB2 within thyroid carcinoma cells suppressed cancer cell viability, the capacity of DNA synthesis, cell invasion, cell migration, and the protein levels of proliferating markers. Let-7d directly targeted DIO3OS and NF-κB2; DIO3OS knockdown upregulated let-7d expression. The overexpression of let-7d suppressed cancer cell viability, the capacity of DNA synthesis, cell invasion, cell migration, as well as the protein levels of proliferating markers. Let-7d inhibition remarkably attenuated the functions of DIO3OS knockdown in NF-κB2 expression and thyroid cancer cell phenotype. In conclusion, DIO3OS/let-7d/NF-κB2 axis regulates the viability, DNA synthesis capacity, invasion, and migration of thyroid cancer cells. The clinical application of this axis needs further in vivo and clinical investigation.

SP1-induced HOXD-AS1 promotes malignant progression of cholangiocarcinoma by regulating miR-520c-3p/MYCN

The purpose of this article is to explore the function and mechanism of HOXD-AS1 in cholangiocarcinoma. TCGA, StarBase and JASPAR were applied to predict the differential expression and molecular mechanism. The qRT-PCR was conducted to detect molecular expression. The effect of HOXD-AS1 on tumor proliferation, metastasis and stemness was measured through corresponding experiments. ChIP, luciferase reporter and RIP assays were implemented to explore the regulatory mechanism of HOXD-AS1 in CCA. In this study, HOXD-AS1 expression was significantly upregulated in CCA tissues and cells compared with control groups, respectively. Increased HOXD-AS1 was markedly correlated with lymph node invasion, advanced TNM stage and poor survival of CCA patients. Moreover, HOXD-AS1 was confirmed to be an unfavorable independent prognostic factor for CCA patients. Functionally, gain- and loss-of-function experiments demonstrated that HOXD-AS1 facilitated tumor proliferation, migration, invasion, EMT, stemness and drug resistance in vitro and in vivo. For the mechanism, transcription factor SP1-induced HOXD-AS1 upregulated oncogene MYCN through competitively binding to miR-520c-3p. Furthermore, HOXD-AS1-induced malignant phenotypes were rescued by interfering miR-520c-3p and MYCN, respectively. SP1/HOXD-AS1/miR-520c-3p/MYCN plays a vital role in initiation and progression of CCA, and HOXD-AS1 is expected to be an efficient biomarker and therapeutic target.

Long non-coding RNA (lncRNA) and epithelial-mesenchymal transition (EMT) in colorectal cancer: a systematic review

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer-related death. Epithelial-mesenchymal transition (EMT) is a major process in tumor metastasis development. This systematic review aims to describe the role of long non-coding RNA (lncRNA) in EMT in CRC.

METHODS

The electronic databases, PubMed, Cochrane, and EMBASE, were searched from January1990 to June 2019 to identify studies examining lncRNA and their role in mediating EMT in CRC. Studies examining clinical specimens and/or in vitro experiments were included.

RESULTS

In 61 identified studies, 54 lncRNAs were increased in CRC compared to normal colorectal epithelium. Increased lncRNA expression was frequently associated with worse survival. Many lncRNAs mediate their effect through competitive endogenous RNA or transcription factor regulation. The ZEB1, 2/E-cadherin, Wnt/β-catenin signaling, and chromatin remodeling pathways are discussed in particular.

CONCLUSIONS

lncRNAs are major regulators of EMT and predictor adverse outcome in CRC patients. Future research must focus on delineating lncRNA function prior to potential clinical use.

CircAPLP2 regulates the proliferation and metastasis of colorectal cancer by targeting miR-101-3p to activate the Notch signalling pathway

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers, and it has a poor prognosis. Emerging evidence shows that circular RNAs (circRNAs) may act as good therapeutic targets for cancers due to their abundance and stability. However, their regulatory role in CRC needs further investigation. This study revealed that circAPLP2 was upregulated and miR-101-3p was downregulated in CRC tissues and cells compared to normal controls. Knockdown of circAPLP2 and overexpression of miR-101-3p inhibited the cell proliferation, migration and invasion and induced the apoptosis of CRC cells. circAPLP2 acted as a miR-101-3p sponge to upregulate its target gene Notch1, which activated cascades of proliferation- and metastasis-related proteins (c-Myc, cyclin D1, MMP-2 and MMP-9). Additionally, knockdown of circAPLP2 suppressed tumour growth and liver metastases of CRC in nude mice. Taken together, these results indicate that circAPLP2 promotes proliferation and metastasis by targeting miR-101-3p to activate the Notch signalling pathway in CRC, which provides new insights into the mechanisms underlying CRC malignancy and suggests a new therapeutic target.

Long non-coding RNA KRT16P2/miR-1294/EGFR axis regulates laryngeal squamous cell carcinoma cell aggressiveness

Laryngeal squamous cell carcinoma (LSCC) is one of the most commonly seen head and neck malignancies. Identifying potent markers and/or targets for early diagnosis and individualized therapies for LSCC remains a considerable challenge. The present study analyzed online data and identified lncRNA KRT16P2 as a significantly upregulated long non-coding RNA (lncRNA) in LSCC. KRT16P2 knockdown in LSCC cells inhibited cancer cell proliferation, invasion, and migration. Similar to KRT16P2, EGFR expression was also significantly upregulated in LSCC. KRT16P2 and EGFR were positively correlated in LSCC tissue samples. EGFR knockdown also dramatically inhibited LSCC cell proliferation and aggressiveness (invasion and migration). Through online data and online tools, miR-1294 was predicted to target KRT16P2 and EGFR 3'UTR simultaneously. KRT16P2 inhibited miR-1294 expression, and miR-1294 inhibited EGFR expression through direct binding. miR-1294 overexpression repressed LSCC cell proliferation and aggressiveness. The effects of KRT16P2 silence on the expression of EGFR, LSCC cell proliferation, invasion, and migration, the protein levels of ki-67, PCNA, and cleaved-Caspase 3, as well as the phosphorylation of AKT, were all significantly reversed by miR-1294 inhibition. In conclusion, we demonstrated a lncRNA KRT16P2/miR-1294/EGFR axis that regulates LSCC cell proliferation, invasion, and migration. The clinical application of this axis needs further in vivo and clinical investigation.

LncRNA HOXD-AS1 promotes the metastasis of human hepatocellular carcinoma via modulating miR-326/SLC27A4

Background

Mounting evidences have indicated that long non-coding RNA (lncRNA) HOXD cluster antisense RNA 1 (HOXD-AS1) is dysregulated and participates into the progression of cancers. This study aims to investigate the biological roles and mechanisms of HOXD-AS1 in the metastasis of hepatocellular carcinoma (HCC).

Methods

The quantitative real-time PCR (qPCR) assay was used to assess the level of miR-326 and HOXD-AS1 in HCC tissues and cell lines. The growth of HCC cell was analyzed by using CCK-8 assay and colony formation assay. The migration and invasion of HCC cell were investigated by using wound healing and transwell invasion analysis. The expressions of SLC27A4, N-cadherin and E-cadherin were determined by western blotting. The growth of HCC cell in vivo was assessed by using xenograft model.

Results

Here, we elaborated that HOXD-AS1 was overexpressed in HCC tissues than that in the adjacent normal tissues and the level of HOXD-AS1 was related with the aggressive phenotypes of HCC. Functionally, downregulation of HOXD-AS1 repressed the proliferation, invasion abilities of HCC cell in vitro and the distant metastasis of HCC cell in vivo. Further investigations demonstrated that HOXD-AS1 directly bound with miR-326 and thereby regulated its endogenous target gene, solute carrier family 27 member 4 (SLC27A4).

Conclusions

All these findings indicated that HOXD-AS1-miR-326-SLC27A4 axis participated into the progression of HCC.

Functional roles of lncRNAs in the pathogenesis and progression of cancer

Long noncoding RNAs (lncRNAs) act as regulators of gene expression and pivotal transcriptional regulators in cancer cells via diverse mechanisms. lncRNAs involves a variety of pathological and biological activities, such as apoptosis, cell proliferation, metastasis, and invasion. By using microarray and RNA sequencing, it was identified that dysregulation of lncRNAs affects the tumorigenesis process. Taken together, these lncRNAs are putative biomarker and therapeutic target in human malignancies. In this review, I discuss the latest finding regarding the dysregulation of some important lncRNAs and their diverse mechanisms of these lncRNAs in the pathogenesis and progression of certain cancers; also, I summarize the possible roles of lncRNAs in clinical application for diagnosis and prognosis of cancer.

Antisense lncRNA LDLRAD4-AS1 promotes metastasis by decreasing the expression of LDLRAD4 and predicts a poor prognosis in colorectal cancer

Long noncoding RNAs (lncRNAs) have been revealed to play critical roles in tumor initiation and progression. The antisense lncRNA LDLRAD4-AS1 is the longest lncRNA of LDLRAD4, and its expression levels, cellular localization, precise function, and mechanism in colorectal cancer (CRC) remain unknown. In this study, we observed that lncRNA LDLRAD4-AS1 was located in the nucleus of CRC cells and that lncRNA LDLRAD4-AS1 was upregulated in most CRC specimens and cell lines. Overexpression of lncRNA LDLRAD4-AS1 was correlated with poor prognosis in CRC patients. LncRNA LDLRAD4-AS1 upregulation enhanced the migration and invasion of CRC cells in vitro and facilitated CRC metastasis in vivo. Mechanistic investigations suggested that lncRNA LDLRAD4-AS1 could decrease the expression of LDLRAD4 by disrupting the stability of LDLRAD4 mRNA, resulting in epithelial-to-mesenchymal transition (EMT) through upregulating Snail, thereby promoting metastasis in CRC. Our results demonstrated a previously unrecognized LDLRAD4-AS1-LDLRAD4-Snail regulatory axis involved in epigenetic and posttranscriptional regulation that contributes to CRC progression and metastasis.

Identification of plasma exosomes long non-coding RNA HAGLR and circulating tumor cells as potential prognosis biomarkers in non-small cell lung cancer

Background

The main purpose of this study was to identify the correlation between the expression of long non-coding RNA (lncRNA) HAGLR in plasma exosomes and the detection rate of circulating tumor cells (CTCs) in patients with non-small cell lung cancer (NSCLC).

Methods

LncRNA HAGLR expression was detected in plasma exosomes of 40 patients with NSCLC and 8 healthy subjects using qRT-PCR. CTCs were enriched and separated using CTC-BIOPSY^® abnormal cell separator. The correlations between lncRNA HAGLR expression in plasma exosomes and CTCs of patients with NSCLC and clinical pathological parameters were also analyzed. Bioinformatics analyses indicated HAGLR was evidently down-regulated in NSCLC tissues when compared to normal controls. The relationship between differential expression of HAGLR with different stages of NSCLC and clinical prognosis were elucidated using corresponding statistical methods.

Results

HAGLR was significantly decreased in NSCLC, and there was obvious correlation with overall survival (P<0.05). CTCs were detected in peripheral blood of patients with NSCLC with the positive rate of 70.0%. In lung squamous cell carcinoma (LUSC), compared with the high expression group of HAGLR, the low expression group had a better overall survival (P<0.05). At the same time, the high expression of HAGLR was positively correlated with the high detection rate of CTCs (P<0.05), suggesting that the disease may have a later tumor stage, and poor prognosis.

Conclusions

lncRNA HAGLR and CTCs could be used as potential biomarkers for NSCLC metastasis risk prediction.

TGF-β-induced long non-coding RNA MIR155HG promotes the progression and EMT of laryngeal squamous cell carcinoma by regulating the miR-155-5p/SOX10 axis

Non‑coding RNAs, particularly long non‑coding RNAs (lncRNAs), play important roles in tumorigenesis. The miR‑155 host gene (MIR155HG) lncRNA has been found to play a crucial role in tumor progression. However, the role of MIR155HG in laryngeal squamous cell carcinoma (LSCC) remains unclear. Thus, the aim of the present study was to explore the roles and underlying molecular mechanisms of action of MIR155HG and miR‑155‑5p in LSCC, in an effort to provide novel approaches for the antitumor therapy for LSCC. In the present study, the expression levels of miR‑155‑5p and MIR155HG were detected by reverse tran-scription‑quantitative polymerase chain reaction. In addition, the biological functions of MIR155HG and miR‑155‑5p on LSCC were evaluated in vitro by MTS assay, colony formation assay and Transwell assays, and in vivo by tumorigenesis assays. It was revealed that MIR155HG and miR‑155‑5p were significantly upregulated in LSCC tissues, and were associated with the TNM stage, pathological differentiation and lymph node metastasis. Moreover, the knockdown of MIR155HG and miR‑155‑5p inhibited the proliferation, migration and invasion of LSCC cells, whereas their overexpression exerted the opposite effects in vitro and MIR155HG overexpression promoted tumorigenesis in vivo. Furthermore, MIR155HG downregulation reduced the expression level of miR‑155‑5p. The inhibitory effect of MIR155HG knockdown on malignant behavior was abrogated by miR‑155‑5p overexpression. Bioinformatics analysis and luciferase reporter assay confirmed that miR‑155‑5p contributed to the progression of LSCC by directly binding to the 3' untranslated region of SRY‑related‑HMG‑box 10 (SOX10). In addition, MIR155HG and miR‑155‑5p were upregulated by the induction of transforming growth factor‑β (TGF‑β) and promoted the expression of mesenchymal markers synergistically. On the whole, the findings of the present study indicate a novel role of MIR155HG in the TGF‑β‑induced EMT of LSCC cells by regulating EMT markers through the miR‑155/SOX10 axis. The MIR155HG/miR‑155‑5p/SOX10 axis plays an important role in promoting the progression of LSCC and may thus serve as a potential therapeutic target for LSCC treatment.

Nuclear lncRNA HOXD-AS1 suppresses colorectal carcinoma growth and metastasis via inhibiting HOXD3-induced integrin β3 transcriptional activating and MAPK/AKT signalling

Background

Long noncoding RNAs (lncRNAs) have been indicated to play critical roles in cancer development and progression. LncRNA HOXD cluster antisense RNA1 (HOXD-AS1) has recently been found to be dysregulated in several cancers. However, the expression levels, cellular localization, precise function and mechanism of HOXD-AS1 in colorectal carcinoma (CRC) are largely unknown.

Methods

Real-time PCR and in situ hybridization were used to detect the expression of HOXD-AS1 in CRC tissue samples and cell lines. Gain- and loss-of-function experiments were performed to investigate the biological roles of HOXD-AS1 in CRC cell line. RNA pull down, RNA immunoprecipitation and chromatin immunoprecipitation assays were conducted to investigate the mechanisms underlying the functions of HOXD-AS1 in CRC.

Results

We observed that HOXD-AS1 was located in the nucleus of CRC cells and that nuclear HOXD-AS1 was downregulated in most CRC specimens and cell lines. Lower levels of nuclear HOXD-AS1 expression were associated with poor outcomes of CRC patients. HOXD-AS1 downregulation enhanced proliferation and migration of CRC cells in vitro and facilitated CRC tumourigenesis and metastasis in vivo. Mechanistic investigations revealed that HOXD-AS1 could suppress HOXD3 transcription by recruiting PRC2 to induce the accumulation of the repressive marker H3K27me3 at the HOXD3 promoter. Subsequently, HOXD3, as a transcriptional activator, promoted Integrin β3 transcription, thereby activating the MAPK/AKT signalling pathways.

Conclusion

Our results reveal a previously unrecognized HOXD-AS1-HOXD3-Integrin β3 regulatory axis involving in epigenetic and transcriptional regulation constitutes to CRC carcinogenesis and progression.

Electronic supplementary material

The online version of this article (10.1186/s12943-019-0955-9) contains supplementary material, which is available to authorized users.

Long noncoding RNA HOXD-AS1 in various cancers: a meta-analysis and TCGA data review

Background and aims: HOXD antisense growth-associated long noncoding RNA (HOXD-AS1) was reported to be upregulated in various cancers, such as gastric cancer, hepatocellular carcinoma, colorectal cancer, and glioma. Here, we conducted a meta-analysis and The Cancer Genome Atlas data review to investigate the clinicopathologic and prognostic value of HOXD-AS1 in patients with malignant tumors.

Materials and methods: Systematic literatures were searched from PubMed, Medline, Cochrane Library, Web of Science, EMBASE database, Ovid, Chinese CNKI, and the Chinese WanFang database. The role of HOXD-AS1 in cancers was evaluated by pooled ORs and HRs with 95% CIs. The Cancer Genome Atlas dataset was used to explore the prognostic value of HOXD-AS1 in various cancers.