Role Of ANRIL Research Articles

ANRIL promotes the regulation of colorectal cancer on lymphatic endothelial cells via VEGF-C and is the key target for Pien Tze Huang to inhibit cancer metastasis

lncRNA ANRIL is an oncogene, however the role of ANRIL in the regulation of colorectal cancer on human lymphatic endothelial cells (HLECs) is remain elusive. Pien Tze Huang (PZH, PTH) a Tradition Chinese Medicine (TCM) as an adjunctive medication could inhibit the cancer metastasis, however the mechanism still uncovering. We used network pharmacology, subcutaneous and orthotopic transplanted colorectal tumors models to determine the effect of PZH on tumor metastasis. Differential expressions of ANRIL in colorectal cancer cells, and stimulating the regulation of cancer cells on HLECs by culturing HLECs with cancer cells’ supernatants. Network pharmacology, transcriptomics, and rescue experiments were carried out to verify key targets of PZH. We found PZH interfered with 32.2% of disease genes and 76.7% of pathways, and inhibited the growth of colorectal tumors, liver metastasis, and the expression of ANRIL. The overexpression of ANRIL promoted the regulation of cancer cells on HLECs, leading to lymphangiogenesis, via upregulated VEGF-C secretion, and alleviated the effect of PZH on inhibiting the regulation of cancer cells on HLECs. Transcriptomic, network pharmacology and rescue experiments show that PI3K/AKT pathway is the most important pathway for PZH to affect tumor metastasis via ANRIL. In conclusion, PZH inhibits the regulation of colorectal cancer on HLECs to alleviate tumor lymphangiogenesis and metastasis by downregulating ANRIL dependent PI3K/AKT/VEGF-C pathway.

The Role of ANRIL in Atherosclerosis.

There is a huge number of noncoding RNA (ncRNA) transcripts in the cell with important roles in modulation of different mechanisms. ANRIL is a long ncRNA with 3.8 kb length that is transcribed in the opposite direction of the INK4/ARF locus in chromosome 9p21. It was shown that polymorphisms within this locus are associated with vascular disorders, notably coronary artery disease (CAD), which is considered as a risk factor for life-threatening events like myocardial infarction and stroke. ANRIL is subjected to a variety of splicing patterns producing multiple isoforms. Linear isoforms could be further transformed into circular ones by back-splicing. ANRIL regulates genes in atherogenic network in a positive or negative manner. This regulation is implemented both locally and remotely. While CAD is known as a proliferative disorder and cell proliferation plays a crucial role in the progression of atherosclerosis, the functions of ANRIL and CAD development are intertwined remarkably. This makes ANRIL a suitable target for diagnostic, prognostic, and even therapeutic aims. In this review, we tried to present a comprehensive appraisal on different aspects of ANRIL including its location, structure, isoforms, expression, and functions. In each step, the contribution of ANRIL to atherosclerosis is discussed.

Long non-coding RNA ANRIL promotes proliferation, clonogenicity, invasion and migration of laryngeal squamous cell carcinoma by regulating miR-181a/Snai2 axis.

BackgroundLaryngeal squamous cell carcinoma (LSCC) is the common cancer with poor prognosis. Long non-coding RNA (lncRNA) ANRIL has been proven to play an important role in many cancers. However up to now, the role of ANRIL in LSCC is still poorly understood. The present study aimed to investigate the role and underlying mechanisms of ANRIL and miR-181a in LSCC.MethodsExpression of ANRIL, miR-181a and Snai2 in both LSCC tissues and cells was determined by qRT-PCR. CCK-8 assay, colony formation assay, flow cytometry analysis and transwell assay were conducted to detect cell proliferation, clonogenicity, apoptosis, invasion and migration, respectively. The binding between ANRIL and miR-181a, as well miR-181a and Snai2 was confirmed by dual luciferase reporter assay. Western blotting was used to determine the protein levels of Snail, Slug, E-cadherin, N-cadherin and Vimentin.ResultsANRIL was up-regulated while miR-181a was down-regulated in LSCC tissues. ANRIL was negatively correlated with miR-181a and was positively correlated with Snai1 and Snai2. Dual luciferase reporter assay showed ANRIL could directly sponge miR-181a to counteract its suppression on Snai2, serving as a positive regulator of Snai2. Either knockdown of ANRIL or overexpression of miR-181a significantly inhibited the proliferation, clonogenicity, invasion, migration and epithelial mesenchymal transformation (EMT), as well as promoted the apoptosis of LSCC cells, and knockdown of miR-181a reversed the effects.ConclusionInhibition of ANRIL could suppress cell proliferation, clonogenicity, invasion and migration, as well as enhance cell apoptosis of LSCC cells through regulation of miR-181a/Snai2 axis, indicating that ANRIL might be a promising therapeutic target during the treatment of LSCC.

The 9p21 locus as a potential therapeutic target and prognostic marker in colorectal cancer.

Colorectal cancer (CRC) is a major cause of cancer-related-death worldwide. Despite extensive efforts to identify valid biomarkers for the risk stratification of CRC patients, there are few of proven clinical utility. It is recognized that genetic factors play a major role in determining susceptibility to CRC. Recent genome-wide association studies have demonstrated common genetic variants in a region on chromosome 9p21 associated with an increased risk of CRC. Several genetic polymorphisms have been identified in this region that are associated with CRC. Three genes are located at this locus; CDKN2B(encoding-p15ink4b), CDKN2A (encoding-p16ink4a/p14ARF) and 3' end of CDKN2BAS (termed-antisense-noncoding-RNA in the INK4-locus [ANRIL]). ANRIL has a post-transcriptional modulatory activity, which has been shown to perturb the expression of nearby genes. It also plays an important role in coordinating tissue remodeling through regulation of cell proliferation, apoptosis, aging, extra-cellular matrix remodeling and inflammatory response. However, the role of ANRIL is not well understood in CRC. Hypermethylation of the p14ARF and p16INK4a genes is often found in some tumors, including CRC. However, further studies are necessary to explore the clinical utility of these putative markers in risk stratification, and in the assessment of prognosis. In this review, we have summarized the prognostic and therapeutic potential of the p14ARF and p16INK4a genes in patients with colorectal cancer.

The 9p21 locus: A potential therapeutic target and prognostic marker in breast cancer.

Breast cancer is an important cause of cancer related mortality in women. Despite extensive efforts to identify valid biomarkers for risk stratification, there are relatively few with proven clinical utility. It is recognized that genetic factors play a major role in determining susceptibility to breast cancer. Recent genome-wide-association-studies and gene expression analysis have demonstrated that a locus on chromosome 9p21, which contains three genes; CDKN2B (encoding p15ink4b), CDKN2A (encoding p16ink4a and p14ARF) and the 3' end of CDKN2BAS (an antisense noncoding RNA in the INK4 locus [ANRIL]) are associated with an increased risk of this malignancy. ANRIL has a post transcriptional modulatory activity, which has been shown to perturb the expression of nearby genes and may play an important role in coordinating tissue remodeling through regulation of cell proliferation, apoptosis, aging, extra-cellular matrix remodeling, and inflammatory response. However, the role of ANRIL is not well understood in breast cancer. Hypermethylation of the p14ARF and p16INK4a genes is found in some tumor types. Nevertheless, further studies are necessary to confirm the clinical utility of these putative markers in risk stratification, or assessing prognosis. In this review, we have summarized the prognostic and therapeutic potential of the p14ARF and p16INK4a genes in patients with breast cancer.

ANRIL: a pivotal tumor suppressor long non-coding RNA in human cancers.

Long non-coding RNAs (lncRNAs) are a family of non-protein-coding RNAs with length more than 200 nucleotides. LncRNAs played important roles in many biological processes such as cell development, proliferation, invasion and migration. Deregulation of LncRNAs was found in multiple tumors where they can act as a tumor suppressor gene or oncogene. LncRNA ANRIL was identified as an oncogene involved in a number of tumors such as gastric cancer, lung cancer, hepatocellular carcinoma, and esophageal squamous cell carcinoma. Inhibition of ANRIL suppressed the cancer cell proliferation, migration and invasion. Increasing data has showed that ANRIL may act as a diagnostic and prognostic biomarker for some tumors. In our review, we summarize an overview of current knowledge concerning the expression and role of ANRIL in various cancers.

ANRIL regulates the proliferation of human colorectal cancer cells in both two- and three-dimensional culture.

ANRIL is a long noncoding RNA transcribed from the INK4 locus that encodes three tumor suppressor genes, p15, p16, and ARF. Previous studies demonstrated that ANRIL represses p15 and p16, which positively regulate the pRB pathway, leading to repression of cellular senescence of human normal fibroblasts. However, the role of ANRIL in cancer cell proliferation is less well understood. Here we report that ANRIL is involved in the proliferation of colorectal cancer HCT116 cells in two- and three-dimensional culture. Silencing ANRIL by both transfection with small interfering RNA and retrovirally produced small hairpin RNA reduced HCT116 cell proliferation in both two- and three-dimensional culture. HCT116 cells depleted for ANRIL were arrested in the S phase of cell cycle. Notably, silencing ANRIL did not result in the activation of expression of the INK4 locus. These results suggest that ANRIL positively regulates the proliferation of HCT116 cells in two- and three-dimensional culture in a p15/p16-pRB pathway-independent manner.

Abstract 157: LncRNA ANRIL indicates a potential prognostic biomarker in gastric cancer and promotes tumor growth by silencing of miR-99a/miR-449a

Abstract Long noncoding RNAs are involved in several kinds of cancers. Here, we reported that ANRIL (CDKN2B-AS1), a 3.8-kb long noncoding RNA, recruiting and binding to PRC2, was generally upregulated in human gastric cancer (GC) tissues. In a cohort of 120 GC patients, the higher expression of ANRIL was significantly correlated with higher TNM stages (P = 0.041) and larger tumor sizes (P = 0.001). Multivariate analyses revealed that ANRIL expression served as an independent predictor for overall survival (OS) (P = 0.036). Further experiments revealed that the knockdown of ANRIL significantly repressed the proliferation of GC cell lines both in vitro and in vivo. We also showed that E2F1 could induce ANRIL and ANRIL-mediated growth promotion is partly due to epigenetic repression of miR-99a/miR-449a in Trans (controlling the targets_mTOR and CDK6/E2F1 pathway) by binding to PRC2, thus forming a positive feedback loop, continuing to promote GC cell proliferation. To our knowledge, this is the first report which showed that the role of ANRIL in the progression of GC and ANRIL could crosstalk with microRNAs in epigenetic level. Our results suggest that ANRIL, as a growth regulator, may serve as a potential prognostic biomarker and target for new therapies in human GC. Citation Format: Zhi Xu, Jinfei Chen, John M. Luk, Wei De. LncRNA ANRIL indicates a potential prognostic biomarker in gastric cancer and promotes tumor growth by silencing of miR-99a/miR-449a. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 157. doi:10.1158/1538-7445.AM2015-157

Long noncoding RNA ANRIL indicates a poor prognosis of gastric cancer and promotes tumor growth by epigenetically silencing of miR-99a/miR-449a.

Long noncoding RNAs are involved in diseases including cancer. Here, we reported that ANRIL (CDKN2B-AS1), a 3.8-kb long noncoding RNA, recruiting and binding to PRC2, was generally upregulated in human gastric cancer (GC) tissues. In a cohort of 120 GC patients, the higher expression of ANRIL was significantly correlated with a higher TNM stage (P=0.041) and tumor size (P=0.001). Multivariate analyses revealed that ANRIL expression served as an independent predictor for overall survival (P=0.036). Further experiments revealed that ANRIL knockdown significantly repressed the proliferation both in vitro and in vivo. We also showed that E2F1 could induce ANRIL and ANRIL-mediated growth promotion is in part due to epigenetic repression of miR-99a/miR-449a in Trans (controlling the targets--mTOR and CDK6/E2F1 pathway) by binding to PRC2, thus forming a positive feedback loop, continuing to promote GC cell proliferation. To our knowledge, this is the first report showed that the role of ANRIL in the progression of GC and ANRIL could crosstalk with microRNAs in epigenetic level. Our results suggest that ANRIL, as a growth regulator, may serve as a candidate prognostic biomarker and target for new therapies in human gastric cancer.

C Modulation of anril expression may mediate the association between chromosome 9p21 variants and coronary atherosclerosis risk

<h3>Introduction</h3> Single nucleotide polymorphisms (SNPs) on chromosome 9p21 are associated with coronary artery disease, stroke, diabetes and several cancers. The mechanisms mediating these associations are unknown, but risk variants are mainly non-coding and may act through regulation of gene expression in cis. We investigated whether 9p21 SNPs were associated with total and allelic expression of the three nearest genes; the cell-cycle inhibitors CDKN2A/CDKN2B, and a non-coding RNA of unknown function, ANRIL. <h3>Methods</h3> We genotyped 56 SNPs, selected to tag the common variation in the region and include SNPs with reported functional effects. We studied peripheral blood expression in two populations of healthy volunteers: 177 British Caucasians and 310 mixed-ancestry South Africans. Total expression was measured using TaqMan real-time PCR. Allelic expression was quantified by mass spectrometry (Sequenom) and analysed by novel methodology using data from two transcribed SNPs per gene. Association between mapping SNPs and expression was assessed using likelihood ratio tests. <h3>Results</h3> Total expression of CDKN2A, CDKN2B and ANRIL was correlated (p&lt;0.05), suggesting that they are co-regulated. Allelic expression was also correlated (p&lt;0.05), suggesting that transcription is influenced by shared cis acting elements. SNP associations mapped by total and allelic expression were similar (r=0.96, p=2×10⁻⁹²), but the power to detect effects was greater for allelic expression, indicating the presence of substantial trans-acting effects on expression. The proportion of expression variance attributable to cis-acting effects was 8% for CDKN2A, 5% for CDKN2B, and 20% for ANRIL. SNP associations were similar in the two populations (r=0.94, p=1×10⁻⁷²) which permitted analysis of the combined dataset (Abstract C figure 1). Multiple SNPs were independently associated with expression of each gene (p&lt;0.01), suggesting that several sites may modulate disease susceptibility. Risk SNPs for coronary disease and stroke were all highly associated with allelic expression of ANRIL (all p&lt;1×10⁻⁷), whilst association with the other two genes was only detectable for some. Risk alleles all correlated with ANRIL under-expression (up to 1.9-fold). Individual SNPs were associated with opposite effects on ANRIL and CDKN2B expression, suggesting a possible role of ANRIL in CDKN2B regulation. <h3>Conclusions</h3> Multiple independent cis-acting SNPs influence CDKN2A, CDKN2B and ANRIL expression. Risk SNPs correlate with reduced ANRIL expression, suggesting that ANRIL down-regulation mediates susceptibility to atherosclerosis; this pathway may be an important target for future therapies. Allelic expression has greater power than total expression for mapping cis-acting effects; this has implications for future studies investigating SNP effects on gene expression at other loci.