LINC00472 suppresses oral squamous cell carcinoma growth by targeting miR-455-3p/ELF3 axis

Competing endogenous RNAs in head and neck squamous cell carcinoma: a review

Our understanding of RNA biology has evolved with recent advances in research from it being a non-functional product to molecules of the genome with specific regulatory functions. Competitive endogenous RNA (ceRNA), which has gained prominence over time as an essential part of post-transcriptional regulatory mechanism, is one such example. The ceRNA biology hypothesis states that coding RNA and non-coding RNA co-regulate each other using microRNA (miRNA) response elements. The ceRNA components include long non-coding RNAs, pseudogene and circular RNAs that exert their effect by interacting with miRNA and regulate the expression level of its target genes. Emerging evidence has revealed that the dysregulation of the ceRNA network is attributed to the pathogenesis of various cancers, including the head and neck squamous cell carcinoma (HNSCC). This is the most prevalent cancer developed from the mucosal epithelium in the lip, oral cavity, larynx and pharynx. Although many efforts have been made to comprehend the cause and subsequent treatment of HNSCC, the morbidity and mortality rate remains high. Hence, there is an urgent need to understand the holistic progression of HNSCC, mediated by ceRNA, that can have immense relevance in identifying novel biomarkers with a defined therapeutic intervention. In this review, we have made an effort to highlight the ceRNA biology hypothesis with a focus on its involvement in the progression of HNSCC. For the identification of such ceRNAs, we have additionally highlighted a number of databases and tools.

RUNX1/miR-429 feedback loop promotes growth, metastasis, and epithelial-mesenchymal transition in oral squamous cell carcinoma by targeting ITGB1

This study aimed to explore the role of miR-429 on the progression of oral squamous cell carcinoma (OSCC). OSCC cell lines were transfected with miR-429 mimic, pcDNA3.1-RUNX1, or pcDNA3.1-ITGB1, and their cell viability, apoptosis, migration, and invasion abilities were analyzed by cell counting, terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, wound healing, and transwell assays, respectively. Furthermore, luciferase reporter assay, RNA pull-down, and ChIP were used to assess the regulation of miR-429, RUNX1, and ITGB1 expression in OSCC. Lastly, the biological role of the RUNX1/miR-429 feedback loop was explored in nude mice. The results revealed that miR-429 level was down-regulated, while RUNX1 and ITGB1 levels were up-regulated in OSCC tissues and that miR-429 was negatively correlated with RUNX1 and ITGB1 in OSCC tissues. Transfection of miR-429 mimic suppressed OSCC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). Moreover, we found that miR-429 participated in OSCC progression by directly targeting ITGB1. Additionally, we found that RUNX1 negatively regulated miR-429 expression by binding to its promoter. Our results also revealed that the RUNX1/miR-429 feedback loop regulated ITGB1 expression and that RUNX1 overexpression rescued the inhibitory effects of miR-429 mimic on OSCC cells. In addition, miR-429 mimic significantly suppressed tumor growth, inflammatory cell infiltration, EMT, and ITGB1 expression in vivo, which were inhibited by RUNX1 overexpression. Altogether, these results indicate that the RUNX1/miR-429 feedback loop promoted growth, metastasis, and EMT in OSCC by targeting ITGB1.

LINC00847 drives pancreatic cancer progression by targeting the miR-455-3p/HDAC4 axis

Introduction

Pancreatic cancer (PC) is a common malignant tumor of the digestive system, posing a serious threat to the life of patients. This study aims to investigate the role of LINC00847 and the LINC00847/miR-455-3p/HDAC4 mechanism in PC progression.

Material and methods

The RNA levels of LINC00847, miR-455-3p and HDAC4 were determined by RT-qPCR. HDAC4 protein level was assessed by western blotting. Colony formation and CCK-8 assays were employed to test the proliferation of PC cells. Transwell and scratch assays were conducted to evaluate the cell invasive and migratory abilities, respectively. The effect of LINC00847 silencing on PC cells in vivo was verified using a mouse xenograft model. The correlation among LINC00847, miR-455-3p and HDAC4 was ascertained by dual-luciferase reporter (DLR) assay and Pearson's correlation analysis.

Results

The result showed that LINC00847 mainly localized in the cytoplasm was upregulated in PC cells and tissues. Downregulating LINC00847 hindered migration, proliferation, and invasion of PC cells in vitro. Moreover, it also suppressed tumor growth in an in vivo xenograft model. LINC00847 was found to directly target miR-455-3p. miR-455-3p overexpression inhibited cell proliferation and invasion. In addition, HDAC4 was confirmed to be a target gene of miR-455-3p, and HDAC4 overexpression overturned the impact of LINC00847 knockdown on PC cell progression.

Conclusions

Our findings reveal that LINC00847 potentially plays a key role in the carcinogenesis of PC progression. This effect may be mediated via regulating the miR-455-3p/HDAC4 axis. This study provides insights into the intricate molecular mechanisms underlying PC and opens avenues for potential therapeutic interventions.

Novel genome-wide DNA methylation profiling reveals distinct epigenetic landscape, prognostic model and cellular composition of early-stage lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) has been a leading cause of cancer-related mortality worldwide. Early intervention can significantly improve prognosis. DNA methylation could occur in the early stage of tumor. Comprehensive understanding the epigenetic landscape of early-stage LUAD is crucial in understanding tumorigenesis.

METHODS

Enzymatic methyl sequencing (EM-seq) was performed on 23 tumors and paired normal tissue to reveal distinct epigenetic landscape, for compared with The Cancer Genome Atlas (TCGA) 450K methylation microarray data. Then, an integrative analysis was performed combined with TCGA LUAD RNA-seq data to identify significant differential methylated and expressed genes. Subsequently, the prognostic risk model was constructed and cellular composition was analyzed.

RESULTS

Methylome analysis of EM-seq comparing tumor and normal tissues identified 25 million cytosine-phosphate-guanine (CpG) sites and 30,187 differentially methylated regions (DMR) with a greater number of untraditional types. EM-seq identified a significantly higher number of CpG sites and DMRs compared to the 450K microarray. By integrating the differentially methylated genes (DMGs) with LUAD-related differentially expressed genes (DEGs) from the TCGA database, we constructed prognostic model based on six differentially methylated-expressed genes (MEGs) and verified our prognostic model in GSE13213 and GSE42127 dataset. Finally, cell deconvolution based on the in-house EM-seq methylation profile was used to estimate cellular composition of early-stage LUAD.

CONCLUSIONS

This study firstly delves into novel pattern of epigenomic DNA methylation and provides a multidimensional analysis of the role of DNA methylation revealed by EM-seq in early-stage LUAD, providing distinctive insights into its potential epigenetic mechanisms.

Luteolin impacts deoxyribonucleic acid repair by modulating the mitogen-activated protein kinase pathway in colorectal cancer

This study aimed to investigate the effects of luteolin on colorectal cancer (CRC) and explore its underlying mechanism. HCT-116 and HT-29 cells were treated with luteolin, cisplatin, or selumetinib. The cell survival, cell proliferation, apoptosis and cell cycle distribution, and DNA damage were detected using Cell Counting Kit-8, colony formation, flow cytometry, and immunofluorescence staining analysis, respectively. Western blotting was used to detect the expression of apoptosis-related, cycle-related, DNA-damage-related, and mitogen-activated protein kinase (MAPK) pathway-related proteins. Luteolin showed inhibitory effects on cellular growth by reducing cell survival and proliferation, inducing apoptosis and DNA damage, and arresting the cell cycle in a concentration-dependent manner in HCT-116 and HT-29 cells. Meanwhile, luteolin increased the expression of pro-apoptotic proteins, p-CHK1 (central to the induction of cell cycle arrest), and DNA excision repair protein and decreased anti-apoptotic proteins, G2-M phase-related proteins, and DNA repair proteins. The combination of cisplatin and luteolin significantly decreased cell survival and increased the apoptosis rate of HCT-116 and HT-29 cells compared with cisplatin alone. Bioinformatic analysis using the Comparative Toxicogenomics Database and STITCH and MalaCards databases showed that the MAPK pathway is involved in the pharmacology of luteolin. Furthermore, western blotting demonstrated that luteolin plays an inhibitory role by suppressing the MAPK signaling pathway in CRC, which is enhanced when combined with selumetinib. Luteolin can also prevent tumourigenesis in CRC in vivo. In conclusion, luteolin suppressed cell proliferation, blocked the cell cycle, and induced DNA damage and apoptosis progression in CRC cells by mediating the MAPK pathway