Diagnostic model of combined ceRNA and DNA methylation related genes in esophageal carcinoma

The short peptide encoded by long non-coding RNA RNF217-AS1 inhibits stomach cancer tumorigenesis, macrophage recruitment, and pro-inflammatory responses

Certain long non-coding RNAs (lncRNAs) have potential peptide-coding abilities. Here, the role and molecular basis of the RNF217-AS1-encoded peptide in stomach cancer (SC) tumorigenesis were explored. Here, lncRNAs associated with SC pathogenesis and macrophage infiltration and lncRNAs with peptide-coding potential were searched by bioinformatics analysis. The gene mRNA and protein levels were examined by RT-qPCR and western blot assays, respectively. Cell viability, migratory, and invasive abilities were measured by CCK-8, Transwell migration, and Transwell invasion assays, respectively. The potential biological processes related to lncRNA RNF217-AS1 were identified by single-gene GSEA analysis. The effect of RNF217-AS1-encoded peptide on SC tumorigenesis was examined by mouse xenograft experiments. The results showed that lncRNA NR2F1-AS1 and RNF217-AS1 were differentially expressed and associated with macrophage infiltration in SC, and they had the ability to translate into short peptides. The RNF217-AS1 ORF-encoded peptide could reduce SC cell viability, inhibit cell migration and invasion, as well as hinder the development of SC xenograft tumors. The RNF217-AS1 ORF-encoded peptide in human SC AGS cells suppressed THP-1 cell migration, triggered the differential expression of CXCL1/CXCL2/CXCL8/CXCL12, and inactivated the TLR4/NF-κB/STAT1 signaling pathways. As a conclusion, the RNF217-AS1 ORF-encoded peptide hindered SC progression in vitro and in vivo and suppressed macrophage recruitment and pro-inflammatory responses in SC.

A novel method to identify and characterize personalized functional driver lncRNAs in cancer samples

Cancer is a highly heterogeneous disease, and different individuals of the same cancer type can display different therapeutic effects and prognosis. Genetic variation of long non-coding RNA is the key factor driving tumor development, and plays an important role in genetic and biological heterogeneity. Therefore, it is of great significance to identify lncRNA as a driving factor in the non-coding region and explain its function in tumors for revealing the pathogenesis of cancer. In this study, we developed an integrated method to identify Personalized Functional Driver lncRNAs (PFD-lncRNAs) by integrating the DNA copy number data, gene expression data, and the biological subpathways information. Then, we applied the method to identify 2695 PFD-lncRNAs in 5334 samples across 19 cancer types. We performed an analysis of the association between PFD-lncRNAs and drug sensitivity, which provides medication guidance in disease therapy and drug discovery in the individual. Our research is of great significance for elucidating the biological roles of lncRNA genetic variation in cancer, revealing the related mechanism of cancer, and providing novel insights for individualized medicine.

Long non-coding RNA BBOX1-antisense RNA 1 enhances cell proliferation and migration and suppresses apoptosis in oral squamous cell carcinoma via the miR-3940-3p/laminin subunit gamma 2 axis

Long non-coding RNAs (lncRNAs) play an essential role in oral squamous cell carcinoma (OSCC). We aimed to demonstrate the effects of lncRNA gamma-butyrobetaine hydroxylase 1 (BBOX1)-antisense RNA 1 (AS1) in OSCC and its regulatory mechanisms. The levels of BBOX1-AS1, microRNA (miR)-3940-3p, and laminin subunit gamma 2 (LAMC2) in OSCC were determined using reverse transcription-quantitative polymerase chain reaction. The correlations among BBOX1-AS1, miR-3940-3p, and LAMC2 were validated using luciferase, pull-down, and RNA immunoprecipitation assays. Cell proliferation, migration, and apoptosis were examined. BBOX1-AS1 and LAMC2 were notably overexpressed in OSCC, while miR-3940-3p showed the opposite trend. BBOX-1-AS1 silencing reduced the cell proliferation and migration, while promoting apoptosis. Mechanistically, BBOX1-AS1 modulates LAMC2 expression by competitively binding to miR-3940-3p. miR-3940-3p inhibition alleviated the inhibitory effects of BBOX1-AS1 deficiency on OSCC development. LAMC2 knockdown reversed these changes. Our results revealed that BBOX1-AS1 promotes the malignant phenotype of OSCC cells via the upregulation of LAMC2 expression by targeting miR-3940-3p, indicating that BBOX1-AS1 may be a novel target for OSCC intervention.

Long non-coding RNA LINC00680 functions as a ceRNA to promote esophageal squamous cell carcinoma progression through the miR-423-5p/PAK6 axis

Background

Esophageal squamous cell carcinoma (ESCC) is a common invasive malignancy worldwide with poor clinical outcomes. Increasing amount of long non-coding RNAs (lncRNAs) have been reported to be involved in cancer development. However, lncRNAs that are functional in ESCC and the underlying molecular mechanisms remain largely unknown.

Methods

Transcriptomic analysis was performed to identify dysregulated lncRNAs in ESCC tissue samples. The high expression of LINC00680 in ESCC was validated by RT-qPCR, and the oncogenic functions of LINC00680 was investigated by cell proliferation, colony formation, migration and invasion assays in ESCC cells in vitro and xenografts derived from ESCC cells in mice. RNA-seq, competitive endogenous RNA (ceRNA) network analysis, and luciferase reporter assays were carried out to identify LINC00680 target genes and the microRNAs (miRNAs) bound to LINC00680. Antisense oligonucleotides (ASOs) were used for in vivo treatment.

Results

Transcriptome profiling revealed that a large number of lncRNAs was dysregulated in ESCC tissues. Notably, LINC00680 was highly expressed, and upregulation of LINC00680 was associated with large tumor size, advanced tumor stage, and poor prognosis. Functionally, knockdown of LINC00680 restrained ESCC cell proliferation, colony formation, migration, and invasion in vitro and inhibited tumor growth in vivo. Mechanistically, LINC00680 was found to act as a ceRNA by sponging miR-423-5p to regulate PAK6 (p21-activated kinase 6) expression in ESCC cells. The cell viability and motility inhibition induced by LINC00680 knockdown was significantly reversed upon PAK6 restoration and miR-423-5p inhibition. Furthermore, ASO targeting LINC00680 substantially suppressed ESCC both in vitro and in vivo.

Conclusions

An oncogenic lncRNA, LINC00680, was identified in ESCC, which functions as a ceRNA by sponging miR-423-5p to promote PAK6 expression and ESCC. LINC00680/miR-423-5p/PAK6 axis may serve as promising diagnostic and prognostic biomarkers and therapeutic targets for ESCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01539-3.

Long non-coding RNA HCP5 in cancer

Cancer remains a major threat to human health worldwide. Long non-coding RNA (lncRNA) comprises a group of single-stranded RNA with lengths longer than 200 bp. LncRNAs are aberrantly expressed and play a variety of roles involving multiple cellular processes in cancer. Histocompatibility leukocyte antigen complex P5 (HCP5), initially reported in 1993, is an important lncRNA located between the MICA and MICB genes in MHC I region. HCP5 is involved many autoimmune diseases as well as malignancies. Abnormal HCP5 expression occurs in many types of cancer and its dysregulation appears closely associated with tumor progression. HCP5 is also involved in anti-tumor drug resistance as well. As such, HCP5 represents a promising biomarker and therapeutic target in cancer. In this review, we summarize recent researches and provide an overview of the role and mechanism of HCP5 in human cancer.