MNX1-AS1 accelerates the epithelial-mesenchymal transition in osteosarcoma cells by activating MNX1 as a functional oncogene

Crosstalk of Histone and RNA Modifications Identified a Stromal-Activated Subtype with Poor Survival and Resistance to Immunotherapy in Gastric Cancer

Emerging evidence has revealed the pivotal role of epigenetic modifications in shaping the tumor microenvironment (TME). However, crosstalk between different modification types and their clinical relevance in cancers remain largely unexplored. In this study, using ChIP/MeRIP-seq data of seven human gastric cell lines, we systematically characterized the crosstalk of four epigenetic modification types including H3K4me1, H3K4me3, H3K27ac, and N6-methyladenosine (m6A) and identified a recurrent subtype with high FTO expression and low HDAC1 expression across three independent gastric cancer (GC) cohorts, which we named the epigenetic-modification-dysregulated (EMD) subtype. Patients of the EMD subtype were featured with poor survival, stromal activation, and immune suppression. Extensive relevance to clinical characteristics was observed in the EMD subtype, including the Lauren classification, MSI status, histological grade, TNM stage, the Asian Cancer Research Group classification, and the immune/fibrotic classification. An EMD score was then constructed using WGCNA and ssGSEA algorithms, to precisely recognize the EMD subtype and indicate prognosis and response to immunotherapy in multiple independent GC cohorts. Correlations of the EMD score with tumor mutation burden, tumor purity, aneuploidy score, tumorigenic pathways, TME characteristics, and FTO/HDAC1 ratio were measured. In vitro experiments were performed to demonstrate the correlation between FTO and the epithelial–mesenchymal transition pathway, which suggested FTO as a targetable vulnerability for GC patients with a high EMD score. Altogether, by comprehensively analyzing the epigenetic modification patterns of 1518 GC patients, we identified a novel stromal-activated subtype with poor survival and resistance to immunotherapy, which might benefit from the combined immune checkpoint inhibition therapy with FTO inhibition.

Clinical significance of long noncoding RNA MNX1-AS1 in human cancers: a meta-analysis of cohort studies and bioinformatics analysis based on TCGA datasets

MNX1-AS1 expression has been proposed to be abnormally upregulated in multiple human malignancies and be linked with the survival outcome of patients. However, relevant conclusions were yielded based on the limited samples. Therefore, we herein implemented a meta-analysis of the published cohort studies to further decipher the relationship of MNX1-AS1 level to prognosis and clinicopathological features in various cancers. Additionally, using The Cancer Genome Atlas (TCGA) datasets we carried out a bioinformatics analysis to make a further evaluation on the prognostic value of MNX1-AS1 expression. The results of meta-analysis indicated elevated MNX1-AS1 level closely correlated with poorer overall survival (OS) (HR = 1.97, 95% CI, 1.73-2.24; P < 0.00001), and disease-free survival (DFS) (HR = 2.24, 95% CI, 1.48-3.38; P = 0.0001) in cancers, which was confirmed by the bioinformatics analysis. Besides, it was observed the upregulated MNX1-AS1 level was significantly related to invasion depth, disease stage, tumor metastasis, and differentiation. Collectively, high MNX1-AS1 level correlated with poor survival outcome and aggressive clinicopathological characteristics in various cancers, suggesting that MNX1-AS1 may be applied as a prognostic marker and even a therapeutic target. Nevertheless, more high-quality studies designed with a large sample size should be conducted to further determine the clinical role of MNX1-AS1 in specific cancer types.

NCK1-AS1 promotes the progression of lung squamous cell carcinoma through transcriptionally upregulating NCK1 via interacting with MYC

Lung squamous cell carcinoma (LUSC) is a prevalent subtype of nonsmall cell lung cancer (NSCLC). Dysregulated long noncoding RNAs (lncRNAs) are increasingly identified as pivotal modulators in cancer progression. NCK1 divergent transcript (NCK1-AS1) is a lncRNA that has been proven to be oncogenic in different types of human cancers. However, whether it exerts similar functions in LUSC remains to be elusive. The present study focused on investigating the influence of NCK1-AS1 on the cellular process in LUSC and exploring its underlying mechanism. Through online bioinformatics analysis, we obtained a high NCK1-AS1 level in LUSC tissues. Meanwhile, we confirmed that NCK1-AS1 was upregulated in LUSC cells. Gain- or loss-of-function assays suggested that NCK1-AS1 prompted cell proliferation and migration, whilst impeded cell apoptosis in LUSC. Mechanistically, we revealed that NCK1-AS1 induced the upregulation of its nearby gene NCK adaptor protein 1 (NCK1) at the transcriptional level by interacting with the transcription factor MYC proto-oncogene (MYC). Rescue assays indicated that NCK1 participated in the regulation of NCK1-AS1 on LUSC progression. In conclusion, we firstly demonstrated the oncogenic role of NCK1-AS1 in LUSC and illustrated its downstream molecular mechanism.

FAM83A and FAM83A-AS1 both play oncogenic roles in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer. Nevertheless, the detailed molecular mechanisms of the progression of LUAD remain largely unknown. The present bioinformatics analysis reported that FAM83A and FAM83A-AS1 were upregulated in LUAD tissues and associated with prognosis in patients with LUAD. The purpose of the current study was to investigate the role of FAM83A and its antisense long non-coding (lnc)RNA FAM83A-AS1 in LUAD. Gene Expression Profiling Interactive Analysis was used to screen for potential oncogenes in LUAD and to analyze the clinical significance of FAM83A and FAM83A-AS1. Small interfering RNAs were constructed and transfected into LUAD cells to knock down the expression of FAM83A and FAM83A-AS1. EdU, Cell Counting Kit-8, Transwell and Matrigel assays were performed to detect the proliferation, migration and invasion of LUAD cells. The interaction between FAM83A-AS1, microRNA (miR)-495-3p and FAM83A was explored using a luciferase reporter assay. FAM83A and FAM83A-AS1 were both overexpressed in LUAD tissues compared with adjacent normal tissues. High expression of FAM83A and FAM83A-AS1 predicted worse survival and more advanced clinical stage. Knockdown of FAM83A or FAM83A-AS1 could inhibit the proliferation, migration and invasion of LUAD cells. Moreover, lncRNA FAM83A-AS1 regulated the expression of FAM83A by functioning as competing endogenous RNA for miR-495-3p. These results implicated that FAM83A and FAM83A-AS1 both played oncogenic roles in LUAD and FAM83A-AS1 could regulate the expression of FAM83A by sponging miR-495-3p. The study revealed a novel regulatory mechanism of tumor development in LUAD and FAM83A and FAM83A-AS1 may be novel biomarkers and therapeutic targets for LUAD.

LncRNA MNX1-AS1 promotes progression of intrahepatic cholangiocarcinoma through the MNX1/Hippo axis

Long non-coding RNAs (lncRNAs) have extremely complex roles in the progression of intrahepatic cholangiocarcinoma (ICC) and remain to be elucidated. By cytological and animal model experiments, this study demonstrated that the expression of lncRNA MNX1-AS1 was remarkably elevated in ICC cell lines and tissues, and was highly and positively correlated with motor neuron and pancreas homeobox protein 1 (MNX1) expression. MNX1-AS1 significantly facilitated the proliferation, migration, invasion, and angiogenesis in ICC cells in vitro, and remarkably promoted tumor growth and metastasis in vivo. Further study revealed that MNX1-AS1 promoted the expression of MNX1 via recruiting transcription factors c-Myc and myc-associated zinc finger protein (MAZ). Furthermore, MNX1 upregulated the expression of Ajuba protein via binding to its promoter region, and subsequently, Ajuba protein suppressed the Hippo signaling pathway. Taken together, our results uncovered that MNX1-AS1 can facilitate ICC progression via MNX1-AS1/c-Myc and MAZ/MNX1/Ajuba/Hippo pathway, suggesting that MNX1-AS1 may be able to serve as a potential target for ICC treatment.