H3K27 acetylation‐induced lncRNA EIF3J‐AS1 improved proliferation and impeded apoptosis of colorectal cancer through miR‐3163/YAP1 axis

The EXO1/Polη/Polι axis as a promising target for miR-3163-mediated attenuation of cancer stem-like cells in non-small cell lung carcinoma

BACKGROUND

Cancer stem-like cells (CSLCs) drive tumour progression and chemoresistance. The concerted efforts of EXO1 and TLS polymerases safeguard DNA integrity against chemotherapeutic drugs. In absence of potential drug targets, non-small cell lung carcinoma (NSCLC) patients have few therapeutic options. In current scenario, microRNAs offer a potential avenue for eradicating CSLCs.

METHODS

EXO1 downregulation impact on CSLCs expansion was assessed via flow cytometry. Co-localisation of EXO1, Polη and Polι was validated through co-immunoprecipitation and confocal-imaging. The effects of co-downregulation of Polη and Polι on CSLC survival, repair synthesis, and mutagenesis were evaluated using flow cytometry and immunohistochemistry in cell lines and xenografts. MicroRNA targeting EXO1 was studied for its role in CSLCs regulation.

RESULTS

EXO1 downregulation in NSCLC CSLCs induces DNA lesions, triggering apoptosis and enhances cisplatin sensitivity. It collaborates with Polη and Polι in DNA repair, contributing to cisplatin resistance in CSLCs. Absence of Polη and Polι impairs repair and reduces cisplatin-induced mutagenesis. Co-downregulation of Polη and Polι in xenografts reduces tumour proliferation significantly. MiR-3163 overexpression sensitises CSLCs to cisplatin via targeting EXO1/Polη/Polι axis, as shown in mechanistic studies.

CONCLUSION

This study unveils a novel regulatory pathway involving EXO1/Polη/Polι axis and miR-3163, providing insights into CSLCs regulation in NSCLC. EXO1/Polη/Polι axis targeted by miR-3163, resulting in the inhibition of cell growth and induction of apoptosis in NSCLC CSLCs.

LINC01232 promotes ARNTL2 transcriptional activation and inhibits ferroptosis of CRC cells through p300/H3K27ac

Aim: This study investigated the role of lncRNA LINC01232 in ferroptosis of colorectal cancer (CRC).Materials & methods: Real time quantitative polymerase chain reaction or western blot experiments were performed to examine relevant mRNAs and proteins expression. The kit assays evaluated malondialdehyde, iron, Fe2+ and glutathione levels. ROS levels were verified by flow cytometry. Chromatin immunoprecipitation and RNA immunoprecipitation analysis monitored the correlation among LINC01232, H3K27ac, p300 and ARNTL2.Results: LINC01232 or ARNTL2 knockdown facilitated erastin-induced ferroptosis. The interaction between LINC01232 and p300 resulted in the enhancement of H3K27ac levels at ARNTL2 promoter to promote ARNTL2 transcriptional activity. ARNTL2 overexpression reversed the promoting effect of LINC01232 knockdown on ferroptosis.Conclusion: LINC01232 inhibited the ferroptosis in CRC by epigenetically upregulating the transcriptional activity of ARNTL2.

LncRNA EIF3J-DT promotes chemoresistance in oral squamous cell carcinoma

OBJECTIVES

This study aimed to screen oral squamous cell carcinoma (OSCC) diagnostic and prognostic candidates and investigate the potential functions and mechanisms of candidates in the chemoresistance of OSCC cell lines.

MATERIALS AND METHODS

Differential expression profiling of lncRNA was performed in a large cohort of OSCC patients from the Cancer Genome Atlas database to identify OSCC diagnostic and prognostic candidates. Taxol resistance in OSCC cell lines was analyzed using MTT assay. OSCC cell lines transfected with EIF3J-DT pcDNA or siRNA were used to determine its regulatory effects on apoptosis, cell cycle distribution and autophagy using flow cytometry and western blot.

RESULTS

We identified EIF3J-DT as a candidate for OSCC diagnosis and prognosis. The expression level of EIF3J-DT in OSCC cell lines correlates with taxol resistance. EIF3J-DT silencing attenuated taxol resistance, and EIF3J-DT overexpression enhanced taxol resistance in OSCC cell lines. Silencing of EIF3J-DT reduced taxol resistance by inducing apoptosis, cell cycle arrest, and ATG14-mediated autophagy inhibition in OSCC cell lines.

CONCLUSIONS

We found that EIF3J-DT induced chemoresistance by regulating apoptosis, cell cycle, and autophagy in OSCC cell lines, which EIF3J-DT might provide a novel therapeutic approach for OSCC as well as a diagnostic and prognostic factor.

Intratumor microbiome-derived butyrate promotes lung cancer metastasis

Most recurrences of lung cancer (LC) occur within 3 years after surgery, but the underlying mechanism remains unclear. Here, we collect LC tissues with shorter (<3 years, recurrence group) and longer (>3 years, non-recurrence group) recurrence-free survival. By using 16S sequencing, we find that intratumor microbiome diversity is lower in the recurrence group and butyrate-producing bacteria are enriched in the recurrence group. The intratumor microbiome signature and circulating microbiome DNA can accurately predict LC recurrence. We prove that intratumor injection of butyrate-producing bacteria Roseburia can promote subcutaneous tumor growth. Mechanistically, bacteria-derived butyrate promotes LC metastasis by increasing expression of H19 in tumor cells through inhibiting HDAC2 and increasing H3K27 acetylation at the H19 promoter and inducing M2 macrophage polarization. Depletion of macrophages partially abolishes the metastasis-promoting effect of butyrate. Our results provide evidence for the cross-talk between the intratumor microbiome and LC metastasis and suggest the potential prognostic and therapeutic value of the intratumor microbiome.

Novel histone acetylation-related lncRNA signature for predicting prognosis and tumor microenvironment in esophageal carcinoma

Histone acetylation is one of the most common epigenetic modifications and plays a crucial role in tumorigenesis. However, the prognostic significance of histone acetylation-related lncRNAs (HARlncRNAs) in esophageal carcinoma (ESCA) is not well understood. A total of 653 differentially expressed lncRNAs (DElncRNAs) were identified between 162 ESCA tissues and 11 normal tissues in the TCGA database, and 7 of them were correlated with acetylation regulators. We employed univariate Cox regression analysis, combining it with clinical prognosis information, to select 3 prognostic-related HARlncRNAs for further analysis. Subsequently, we used LASSO regression analysis to construct a risk signature for ESCA and identified C21orf62-AS1 and SSTR5.AS1 as potential biomarkers for the prognosis of ESCA patients. Based on the risk score calculated using the risk signature, we categorized patients into high- and low-risk groups. We identified the risk score as an independent risk factor and validated it in the training, test, and GSE53624 datasets. Additionally, patients categorized by their risk scores exhibited distinct immune statuses, tumor mutation burdens, responses to immunotherapy, and drug sensitivities.

H3K27ac-activated LncRNA NUTM2A-AS1 Facilitated the Progression of Colorectal Cancer Cells via MicroRNA-126-5p/FAM3C Axis

OBJECTIVE

Long non-coding RNAs (lncRNAs) are of great importance in the process of colorectal cancer (CRC) tumorigenesis and progression. However, the functions and underlying molecular mechanisms of the majority of lncRNAs in CRC still lack clarity.

METHODS

A Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect lncRNA NUTM2A-AS1 expression in CRC cell lines. Cell counting kit 8 (CCK-8) assay and flow cytometry were used to examine the biological functions of lncRNA NUTM2A-AS1 in the proliferation and apoptosis of CRC cells. RT-qPCR and western blot were implemented for the detection of cell proliferation-, apoptosis-related proteins, and FAM3C. Bioinformatics analysis and dual- luciferase reporter assays were utilized to identify the mutual regulatory mechanism of ceRNAs.

RESULTS

lncRNA NUTM2A-AS1 notably elevated in CRC cell lines and the silenced of NUTM2A- AS1 declined proliferation and facilitated apoptosis. Mechanistically, NUTM2A-AS1 was transcriptionally activated by histone H3 on lysine 27 acetylation (H3K27ac) enriched at its promoter region, and NUTM2A-AS1 acted as a sponge for miR-126-5p, leading to the upregulation of FAM3C expression in CRC cell lines.

CONCLUSION

Our research proposed NUTM2A-AS1 as an oncogenic lncRNA that facilitates CRC malignancy by upregulating FAM3C expression, which might provide new insight and a promising therapeutic target for the diagnosis and treatment of CRC.

Histone Modification of Colorectal Cancer by Natural Products

Natural products play important roles in the pathogenesis of many human malignancies, including colorectal cancer, and can act as a gene regulator in many cancers. They regulate malignant cell growth through many cellular signal pathways, including Rac family small GTPase 1 (RAC1)/PI3K/AKT (α-serine/threonine-protein kinase), mitogen-activated protein kinase (MAPK), Wnt/β-catenin pathway, transforming growth factor-β (TGF-β), Janus kinase and signal transducer and activator of transcription (JAK-STAT), nuclear factor kappa-B (NF-κB), the Notch pathway, Hippo pathway, and Hedgehog pathway. In this review, we describe the epigenetic roles of several natural products, e.g., platycodin D (PD), ginsenoside Rd, tretinoin, Rutin, curcumin, clove extract, betulinic acid, resveratrol, and curcumin, in colorectal cancer, including their impact on colorectal cancer cell proliferation, apoptosis, invasion, migration, and anti-chemotherapeutic resistance. The aim is to illustrate the epigenetic mechanisms of action of natural products in cancer prevention and treatment, and to provide (1) a theoretical basis for the study of the role of epigenetics in influencing colorectal cancer; (2) new directions for studying the occurrence, development, and prognosis of colorectal cancer; and (3) new targets for treating and preventing colorectal cancer.

Targeting lncRNA DDIT4-AS1 Sensitizes Triple Negative Breast Cancer to Chemotherapy via Suppressing of Autophagy

In this study, it is found that the lncRNA, DNA damage inducible transcript 4 antisense RNA1 (DDIT4-AS1), is highly expressed in triple-negative breast cancer (TNBC) cell lines and tissues due to H3K27 acetylation in the promoter region, and promotes the proliferation, migration, and invasion of TNBC cells via activating autophagy. Mechanistically, it is shown that DDIT4-AS1 induces autophagy by stabilizing DDIT4 mRNA via recruiting the RNA binding protein AUF1 and promoting the interaction between DDIT4 mRNA and AUF1, thereby inhibiting mTOR signaling pathway. Furthermore, silencing of DDIT4-AS1 enhances the sensitivity of TNBC cells to chemotherapeutic agents such as paclitaxel both in vitro and in vivo. Using a self-activatable siRNA/drug core-shell nanoparticle system, which effectively deliver both DDIT4-AS1 siRNA and paclitaxel to the tumor-bearing mice, a significantly enhanced antitumor activity is achieved. Importantly, the codelivery nanoparticles exert a stronger antitumor effect on breast cancer patient-derived organoids. These findings indicate that lncRNA DDIT4-AS1-mediated activation of autophagy promotes progression and chemoresistance of TNBC, and targeting of DDIT4-AS1 may be exploited as a new therapeutic approach to enhancing the efficacy of chemotherapy against TNBC.

Metformin suppresses lung adenocarcinoma by downregulating long non-coding RNA (lncRNA) AFAP1-AS1 and secreted phosphoprotein 1 (SPP1) while upregulating miR-3163

AFAP1-AS1 plays a pro-tumor role in lung cancer. However, no investigation has focused on whether it is involved in the anticancer activity of metformin (Met) in the treatment of lung adenocarcinoma (LUAD). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was performed to detect the expression of long non-coding (lnc)RNA AFAP1-AS1, the microRNA (miR)-3163, and secreted phosphoprotein 1 (SPP1) in LUAD tissues, or of A549 and H3122 cells. Cell Counting Kit-8, wound scratch, and cell invasion assays were performed to evaluate the effect of the overexpression of lncRNA AFAP1-AS1, miR-3163, and SPP1 on the malignant behaviors of A549 and H3122 cells. Phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway-related proteins were detected by Western blot analysis. Dual luciferase reporter or RIP assays were used to determine the interplay between AFAP1-AS1 and miR-3163, or of miR-3163 and SPP1. Met inhibits the malignant characteristics of A549 and H3122 cells in vitro. GEPIA database analysis showed that AFAP1-AS1 is a highly expressed lncRNA in LUAD tissues, which was validated by RT-qPCR. Overexpression of AFAP1-AS1 suppressed the met-mediated anti-tumor activity in A549 and H3122 cells, while AFAP1-AS1 silencing promoted it. Met inhibited AFAP1-AS1 expression, which resulted in reduced proliferation, migration, and invasion in A549 and H3122 cells. This led to AFAP1-AS1-mediated suppression of miR-3163 and, subsequently, the upregulation of SPP1. Met exerts its antitumor activities by regulating the AFAP1-AS1/miR-3163/SPP1/PI3K/Akt/mTOR axis. Our findings deepen our understanding of mechanisms underlying anti-tumor effect of Met in LUAD.

Ferroptosis-Related Long Noncoding RNAs as Prognostic Marker for Colon Adenocarcinoma

Background

The incidence of colon adenocarcinoma (COAD) has been increasing over time. Although ferroptosis and long noncoding RNAs (lncRNAs) have been extensively reported to participate in the tumorigenesis and development of COAD, few studies have investigated the role of ferroptosis-related lncRNAs in the prognosis of COAD.

Methods

Gene-sequencing and clinical data for COAD were obtained from The Cancer Genome Atlas database. The coexpression network was constructed using known ferroptosis-related genes. Cox and least absolute shrinkage and selection operator regression were used to screen ferroptosis-related lncRNAs with prognostic value and to identify a predictive model of COAD. Patients with COAD were divided into low- and high-risk groups according to their risk score. Cases of COAD in the International Cancer Genome Consortium database were included as the testing cohort.

Results

In total, nine lncRNAs (LINC02381, AC105219.1, AC009283.1, LINC01011, ELFN1-AS1, EIF3J-DT, NKILA, LINC01063, and SNHG16) were considered prognostic factors for COAD. Then, a risk score model was established. The overall survival rate of COAD patients was negatively associated with the risk score. Kaplan-Meier analyses in the original and testing cohorts showed similar results. The expression of the lncRNAs in tissue was consistent with the risk score, and the relationship with tumor mutation burden, immunity, and drug sensitivity presented a marked link between the signature and COAD. A nomogram was established for clinical applications.

Conclusions

Nine ferroptosis-related lncRNAs and the established signature have a certain predictive value for prognosis of COAD patients and can be used as potential research targets for exploring treatment of COAD.

LncRNA EIF3J-AS1 functions as an oncogene by regulating MAFG to promote prostate cancer progression

Long non-coding RNAs (lncRNAs) can modulate various biological processes and behaviors in most human cancers. LncRNA EIF3J-AS1 has been reported as an oncogene in various tumors, but whether it exerts functions in malignant progression and gene expression in prostate cancer (PCa) remains unknown. In this study, we investigated the high level of EIF3J‐AS1 in PCa tissues and cells, and used functional assays to show that knocking down EIF3J‐AS1 inhibited PCa cell proliferation and metastatic ability. A preliminary mechanistic investigation also showed that EIF3J‐AS1 may increase the expression of MAF bZIP transcription Factor G (MAFG) in PCa. The expression correlation between EIF3J‐AS1 and MAFG was found to be positive in PCa tissues. Finally, rescue assays showed that MAFG might be involved in the EIF3J-AS1-mediated malignant phenotype in PCa cells. This study demonstrated that EIF3J-AS1/MAFG may play a key role in facilitating PCa progression.

BPIFB1 inhibits vasculogenic mimicry via downregulation of GLUT1-mediated H3K27 acetylation in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) demonstrates significant regional differences and a high incidence in Southeast Asia and Southern China. Bactericidal/permeability-increasing-fold- containing family B member 1 (BPIFB1) is a relatively specific and highly expressed protein in the nasopharyngeal epithelium. BPIFB1 expression is substantially downregulated in NPC and is significantly associated with poor prognosis in patients with NPC. However, the specific molecular mechanism by which BPIFB1 regulates NPC is not well understood. In this study, we found that BPIFB1 inhibits vasculogenic mimicry by regulating the metabolic reprogramming of NPC. BPIFB1 decreases GLUT1 transcription by downregulating the JNK/AP1 signaling pathway. Altered glycolysis reduces the acetylation level of histone and decreases the expression of vasculogenic mimicry-related genes, VEGFA, VE-cadherin, and MMP2, ultimately leading to the inhibition of vasculogenic mimicry. To our knowledge, this is the first report on the role and specific mechanism of BPIFB1 as a tumor suppressor gene involved in regulating glycolysis and vasculogenic mimicry in NPC. Overall, these results provide a new therapeutic target for NPC diagnosis and treatment.

USP53 activated by H3K27 acetylation regulates cell viability, apoptosis, and metabolism in esophageal carcinoma via the AMPK signaling pathway

Esophageal carcinoma (ESCA) is a leading cause of cancer death worldwide, despite an overall decline in the incidence of new cases. However, knowledge of gene expression signatures for risk and prognosis stratification of ESCA is inadequate. Thus, identifying novel molecular biomarkers and therapeutic targets for ESCA might improve its prognosis and treatment. The current study investigated the role of ubiquitin-specific peptidase 53 (USP53), a member of the USP family that exhibits deubiquitinating activity, in ESCA and showed that USP53 is downregulated in ESCA tissues, indicating poor prognosis. USP53 suppresses the proliferation and growth of ESCA cells in vitro and in vivo, whereas its knockdown exerts opposite effects. AMP-activated protein kinase inhibitor reverses the effects of USP53 knockdown. USP53 also inhibits glycolysis, oxidative metabolism, and mitochondrial dynamics. H3K27 acetylation increases USP53 expression by binding to its promoter region. Our study reveals that USP53 is activated by H3K27 acetylation and suppresses ESCA progression by regulating cell growth and metabolism. USP53 is therefore a promising target for ESCA treatment.

Hsa-mir-3163 and CCNB1 may be potential biomarkers and therapeutic targets for androgen receptor positive triple-negative breast cancer

Breast cancer (BC) is the most common malignancy in female, but the role of androgen receptor (AR) in triple-negative breast cancer (TNBC) is still unclear. This study aimed to exam the performance of innovative biomarkers for AR positive TNBC in diagnosis and therapies. Four datasets (GSE42568, GSE45827, GSE54002 and GSE76124) were analyzed by bioinformatic methods and the differential expression genes (DEGs) between the AR positive TNBC tissues and normal tissues were firstly identified by limma package and Venn diagrams. Next, Gene Ontologies (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to explore the relationship between these DEGs. Then, the Protein-protein interaction (PPI) network was constructed. CytoHubba and bioinformatic approaches including Molecular Complex Detection (MCODE), Gene Expression Profiling Interactive Analysis (GEPIA), the Kaplan–Meier (KM) plotter and The Human Pro-tein Atlas (THPA) were used to identify the hub genes. Lastly, a miRNA-hub-gene regulatory axis was constructed by use of Target Scan database and ENCORI database. As a result, a total of 390 common DEGs were identified, including 250 up-regulated and 140 down-regulated. GO and KEGG enrichment analysis showed that the up-regulated DEGs were mostly enriched in the cell division, mitotic nuclear division, nucleosome, midbody, protein heterodimerization activity, cadherin binding involved in cell−cell adhesion, systemic lupus erythematosus and alcoholism, while the down-regulated DEGs were mainly enriched in carbohydrate metabolic process, extracellular space, extracellular region, zinc ion binding and microRNAs in cancer. Then, 13 hub genes (CCNB2, FOXM1, HMMR, MAD2L1, RRM2, TPX2, TYMS, CEP55, AURKA, CCNB1, CDK1, TOP2A, PBK) were selected. The survival analysis revealed that only CCNB1 was associated with significantly poor survival (P <0.05) in TNBC patients. Finally, we found that hsa-miR-3163 took part in the regulation of CCNB1 and constructed a potential hsa-miR-3163-CCNB1 regulatory axis. The results of current study suggest that CCNB1 and hsa-miR-3163 may serve as highly potential prognostic markers and therapeutic targets for AR positive TNBC. Our findings may make contributions to the diagnosis and therapies of AR positive TNBC.

Comprehensive Analysis of Acetylation-Related lncRNAs and Identified AC099850.3 as Prognostic Biomarker in Non-Small Cell Lung Cancer

The present study aimed to analyze the effects of acetylation-related lncRNAs in non-small-cell lung cancer (NSCLC). A total of 399 differentially expressed lncRNAs (DElncRNAs) have been identified between 497 NSCLC tissues and 54 normal tissues in the TCGA database, and 105 of which were correlated with acetylation regulators. By using univariate cox regression analysis and combining it with clinical prognosis information, 12 prognostic-related lncRNAs were selected for the subsequent analysis. The NSCLC patients were divided into two subgroups (cluster 1 and cluster 2) by clustering software, and immunocyte infiltration analysis, microenvironmental analysis, and clinical relevance analysis were performed between the two subgroups. A risk model was also built to further assess the prognosis value of prognostic-related lncRNAs in NSCLC patients. We found that AC099850.3 was significantly higher in both cluster 1 and high-risk subgroups, which may serve as a potential biomarker for the prognosis of NSCLC patients. Then, based on ceRNA competition mechanisms, the pathway enrichment of 105 acetylation-related lncRNAs was conducted by GO and KEGG analyses. We found the acetylation-related lncRNAs were primarily enriched in MAPK and EGFR signaling pathways, which were closely associated with NSCLC development. Finally, we validated the expression levels of AC099850.3 in NSCLC tissues and adjacent non-cancerous tissues and confirmed that AC099850.3 was significantly highly expressed in NSCLC tissues and cells. These results may provide clues for our understanding of the role of acetylation-related lncRNAs and valuable information for future clinical diagnosis and prognosis in NSCLC patients.

Acetylation of H3K27 activated lncRNA NEAT1 and promoted hepatic lipid accumulation in non-alcoholic fatty liver disease via regulating miR-212-5p/GRIA3

Non-alcoholic fatty liver disease (NAFLD) was a world-wide health burden. H3K27 acetylation, long non-coding RNA (lncRNA), and miRNA were all implicated in NAFLD regulation, yet the detailed regulatory mechanism was not well understood. LncRNA NEAT1, miR-212-5p, and GRIA3 expression were detected both in high fatty acid-treated hepatocytes cells and NAFLD patients. Lipid droplets were stained and analyzed by oil red O staining. Expression of fatty acid synthase (FASN), acetyl-CoA carboxylase (ACC), and GRIA3 was detected by qRT-PCR and western blot. RNA level of lncRNA NEAT1 and miR-212-5p was analyzed by qRT-PCR. The binding sequences of lncRNA NEAT1/miR-212-5p and miR-212-5p/GRIA3 were predicted bioinformatically and validated through luciferase assay. ChIP was performed to analyze H3K27 acetylation on the promoter of lncRNA NEAT1. LncRNA NEAT1 and GRIA3 was upregulated, while miR-212-5p was downregulated in NAFLD patients. FFA promoted lncRNA NEAT1 and GRIA3 expression while suppressing miR-212-5p and promoted lipid accumulation as indicated by increased oil red O staining and FAS and ACC expression. ChIP indicated enrichment of H3K27 on NEAT1 promoter. Inhibition of H3K27 acetylation suppressed lncRNA NEAT1 level. Luciferase results indicated direct interaction of NEAT1/miR-212-5p (which was confirmed by RIP) and miR-212-5p/GRIA3. LncRNA NEAT1 knockdown upregulated miR-212-5p level and inhibited FFA-induced lipid accumulation while suppressing GRIA3 expression. Such function was antagonized by miR-212-5p inhibition and GRIA3 knockdown counteracted with miR-212-5p inhibition. H3K27 acetylation was enriched within the promoter of lncRNA NEAT1 and promoted lncRNA NEAT1 transcription. LncRNA NEAT1 could then interact with miR-212-5p and suppress its cellular concentration.

LINC01605, regulated by the EP300-SMYD2 complex, potentiates the binding between METTL3 and SPTBN2 in colorectal cancer

Background

Colorectal cancer (CC) is one of the major contributors to tumor-related death worldwide, and its main cause of death is distant metastasis. Dysregulation of long non-coding RNA (lncRNA) LINC01605 has been implicated in CC. However, its role in metastasis of CC remains elusive. The goal of the study is to uncover the biological function and molecular mechanism of LINC01605 in CC.

Methods

The differentially expressed lncRNAs were first screened from GSE97300, GSE84983, GSE110715, GSE70880, and GSE75970 microarrays. The correlation between the expression of LINC01605 and the clinical phenotypes of enrolled CC patients (n = 134) was subsequently analyzed. The upstream and downstream regulatory mechanisms of LINC01605 in CC were identified through bioinformatics and RNA-seq analyses. Finally, the effects of related factors on CC cell growth and metastasis were confirmed through functional validation experiments.

Results

LINC01605, significantly highly expressed in CC, was a prognostic factor for patients with CC. Functional experiments revealed that LINC01605 knockdown inhibited the proliferatory and metastatic potential of CC cells in vitro and in vivo. Moreover, LINC01605 was regulated by SMYD2-EP300-mediated modifications of histone H3K4me3 as well as H3K27ac. LINC01605 was found to bind to METTL3 and promote the m6A modification of SPTBN2 mRNA, thereby facilitating the translation of SPTBN2.

Conclusions

Overexpression of LINC01605, regulated by SMYD2-EP300-mediated H3K27ac and H3K4me3 modifications, bound to METTL3 protein to promote m6A modification of SPTBN2 mRNA, leading to the development of CC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02180-8.

H3K27ac-induced FOXC2-AS1 accelerates tongue squamous cell carcinoma by upregulating E2F3

BACKGROUND

The important roles of lncRNAs have been reported in cancers, including tongue squamous cell carcinoma (TSCC). Here, we investigated the functional role and molecular mechanisms of lncRNA FOXC2-AS1 in TSCC.

METHODS

The expression level of FOXC2-AS1 in TSCC was determined by RT-qPCR. Its biological role was evaluated through colony formation assay, flow cytometry, wound healing, transwell, and Western blot analyses. The interactions among gene were tested by mechanistic investigations.

RESULTS

FOXC2-AS1 expression was high in TSCC tissues and cells. Functional assays in vitro showed that silencing FOXC2-AS1 restrained cell proliferation, cell cycle, migration, invasion, and EMT. In the mechanism, it was verified that H3K27 acetylation (H3K27ac) triggered an increase in FOXC2-AS1 expression. Furthermore, FOXC2-AS1 was identified as a cytoplasmic lncRNA and served as a ceRNA to upregulate E2F3 expression via sponging miR-6868-5p.

CONCLUSION

H3K27ac-induced FOXC2-AS1 exhibits carcinogenic property in TSCC by the miR-6868-5p/E2F3 axis.

Distinct expression of select and transcriptome-wide isolated 3'UTRs suggests critical roles in development and transition states

Mature mRNA molecules are expected to be comprised of a 5'UTR, a 3'UTR and a coding region (CDS). Unexpectedly, however, there have been multiple recent reports of widespread differential expression of mRNA 3'UTRs and their cognate coding regions (CDS), reflecting the expression of isolated 3'UTRs (i3'UTRs); these i3'UTRs can be highly expressed, often in reciprocal patterns to their cognate CDS. As with other long non-coding (lncRNAs), isolated 3'UTRs are likely to play an important role in gene regulation, but little is known about the contexts in which they are deployed. To illuminate the functions of i3'UTRs, here we carry out in vitro, in vivo and in silico analyses of differential 3'UTR/CDS mRNA ratio usage across tissues, development and cell state changes both for a select list of developmentally important genes as well as by unbiased transcriptome-wide analyses. Across two developmental paradigms we find a distinct switch from high i3'UTR expression for stem cell related genes in proliferating cells to high CDS for these genes in newly differentiated cells. Unbiased transcriptome analysis across multiple gene sets shows that regardless of tissue, genes with high 3'UTR to CDS ratios belong predominantly to gene ontology categories related to cell-type specific functions. In contrast, the gene ontology categories of genes with low 3'UTR to CDS ratios are similar across tissues and relate to common cellular functions. We further show that, at least for some genes, traditional transcriptional start site genomic elements correspond to identified RNAseq 3'UTR peak regions, suggesting that some i3'UTRs may be generated by de novo transcription. Our results provide critical information from which detailed hypotheses for individual i3'UTRs can be tested, with a common theme that i3'UTRs appear poised to regulate cell-specific gene expression and state.

Long noncoding RNA (lncRNA) EIF3J-DT induces chemoresistance of gastric cancer via autophagy activation

Chemotherapy is currently the main treatment for unresectable or advanced postoperative gastric cancers. However, its efficacy is negatively affected by the occurrence of chemoresistance, which severely affects patient prognosis. Recently, dysregulation in autophagy has been suggested as a potential mechanism for chemoresistence, and long noncoding RNA (lncRNA) also shows its regulatory role in cancer drug resistance. Using RNA sequencing, we found that lncRNA EIF3J-DT was highly expressed in drug-resistant gastric cancer cells. In-vitro and in-vivo experiments showed that EIF3J-DT activated autophagy and induced drug resistance in gastric cancer cells by targeting ATG14. Bioinformatics and experimental results showed that EIF3J-DT regulated the expression of ATG14 through direct binding to enhance stabilization of ATG14 mRNA and via blocking the degradation of ATG14 mRNA through competitively binding with microRNA (miRNA) MIR188-3p. Therefore, EIF3J-DT increased the expression of ATG14, contributing to activation of autophagy and chemoresistance. Furthermore, it was confirmed that EIF3J-DT and ATG14 were highly expressed in gastric cancer patients resistant to chemotherapy, and this was closely associated with patient prognosis. In conclusion, EIF3J-DT is involved in the regulation of autophagy and chemoresistance in gastric cancer cells by targeting ATG14. It may be a suitable new target for enhancing chemosensitivity and improving prognosis.Abbreviations: 3-MA: 3-methyladenine; 5-Fu: 5-fluorouracil; ATG: autophagy related; C-CASP3: cleaved caspase 3; C-CASP7: cleaved caspase 7; C-PARP: cleaved PARP; CQ: chloroquine; CR: complete response; DIG: digoxigenin; ESR1: estrogen receptor 1; FBS: fetal bovine serum; FISH: fluorescence in situ hybridization; IHC: immunohistochemistry; ISH: in situ hybridization; lncRNA: long noncoding RNA; miRNA: microRNA; MUT: mutant; NC: negative control; OXA: oxaliplatin; PBS: phosphate-buffered saline; PD: progressive disease; PFA: paraformaldehyde; PR: partial response; qPCR: quantitative polymerase chain reaction; RAPA: rapamycin; SD: stable disease; TEM: transmission electron microscopy; WT: wild type.

The role of cigarette smoke-induced pulmonary vascular endothelial cell apoptosis in COPD

Chronic obstructive pulmonary disease (COPD) is one of the most common chronic respiratory diseases with high morbidity and mortality. It has become the fifth most burdened and the third most deadly disease in the global economy and increases year by year. The prevention and treatment of COPD are urgent. Smoking is the main and most common risk factor for COPD. Cigarette smoke (CS) contains a large number of toxic substances, can cause a series of changes in the trachea, lung tissue, pulmonary blood vessels, and promotes the occurrence and development of COPD. In recent years, the development of epigenetics and molecular biology have provided new guidance for revealing the pathogenesis, diagnosis, and treatment of diseases. The latest research indicates that pulmonary vascular endothelial cell apoptosis initiates and participates in the pathogenesis of COPD. In this review, we summarize the current research on the epigenetic mechanisms and molecular biology of CS-induced pulmonary vascular endothelial cell apoptosis in COPD, providing a new research direction for pathogenesis of COPD and a new target for the diagnosis, treatment, and prevention of COPD.

EIF3J-AS1 promotes glioma cell growth via up-regulating ANXA11 through sponging miR-1343-3p

Background

Glioma is one prevalent malignant tumor originates from the central nervous system. Dysregulation of long non-coding RNAs (lncRNAs) has been found to be a molecular signature behind the pathology of a variety of cancers, including glioma. EIF3J antisense RNA 1 (EIF3J-AS1) is a novel lncRNA, whose performance in carcinogenesis has been unfolded. Nevertheless, the role of EIF3J-AS1 has never been investigated in glioma.

Methods

qRT-PCR analysis was adopted to evaluate the relative levels of RNAs. In vitro functional assays, including colony formation, EdU, TUNEL and caspase-3/8/9 activity assays were conducted to study the impacts of EIF3J-AS1 on glioma. Dual-luciferase activity assays, RNA pull down assay and RIP assay were performed to elucidate molecular interplay among genes.

Results

EIF3J-AS1 was overexpressed in glioma cell lines. Knockdown of EIF3J-AS1 hampered glioma malignant phenotypes. MiR-1343-3p could bind to EIF3J-AS1. Moreover, miR-1343-3p targeted Annexin A11 (ANXA11) in its 3′UTR region. Mechanistically, EIF3J-AS1 relieved ANXA11 from miR-1343-3p silencing in the EIF3J-AS1/miR-1343-3p/ANXA11 RNA induced silencing complex (RISC), thus eliciting promoting effects on glioma progression. MiR-1343-3p inhibitor and ANXA11 overexpression offset the inhibitory impacts of EIF3J-AS1 silencing on glioma development.

Conclusion

EIF3J-AS1/miR-1343-3p/ANXA11 axis significantly affected biological behaviors in glioma, suggesting new therapeutic target for glioma treatment.

Development of Prognostic Indicator Based on Autophagy-Related lncRNA Analysis in Colon Adenocarcinoma

There were no systematic researches about autophagy-related long noncoding RNA (lncRNA) signatures to predict the survival of patients with colon adenocarcinoma. It was necessary to set up corresponding autophagy-related lncRNA signatures. The expression profiles of lncRNAs which contained 480 colon adenocarcinoma samples were obtained from The Cancer Genome Atlas (TCGA) database. The coexpression network of lncRNAs and autophagy-related genes was utilized to select autophagy-related lncRNAs. The lncRNAs were further screened using univariate Cox regression. In addition, Lasso regression and multivariate Cox regression were used to develop an autophagy-related lncRNA signature. A risk score based on the signature was established, and Cox regression was used to test whether it was an independent prognostic factor. The functional enrichment of autophagy-related lncRNAs was visualized using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. Ten prognostic autophagy-related lncRNAs (AC027307.2, AC068580.3, AL138756.1, CD27-AS1, EIF3J-DT, LINC01011, LINC01063, LINC02381, AC073896.3, and SNHG16) were identified to be significantly different, which made up an autophagy-related lncRNA signature. The signature divided patients with colon adenocarcinoma into the low-risk group and the high-risk group. A risk score based on the signature was a significantly independent factor for the patients with colon adenocarcinoma (HR = 1.088, 95%CI = 1.057 - 1.120; P < 0.001). Additionally, the ten lncRNAs were significantly enriched in autophagy process, metabolism, and tumor classical pathways. In conclusion, the ten autophagy-related lncRNAs and their signature might be molecular biomarkers and therapeutic targets for the patients with colon adenocarcinoma.

LncRNA EIF3J-AS1 enhanced esophageal cancer invasion via regulating AKT1 expression through sponging miR-373-3p

Esophageal cancer (ECa) remains a major cause of mortality across the globe. The expression of EIF3J-AS1 is altered in a plethora of tumors, but its role in ECa development and progression are undefined. Here, we show that EIF3J-AS1 is up-regulated in ECa and that its expression correlates with advanced TNM stage (P = 0.014), invasion depth (P = 0.001), positive lymph node metastasis (P < 0.001) and poor survival (OS: P = 0.0059; DFS: P = 0.0037) in ECa. Functional experiments showed that knockdown EIF3J-AS1 inhibited ECa growth and metastasis through in vitro and in vivo experiments. Regarding the mechanism, EIF3J-AS1/miR-373-3p/AKT1 established the ceRNA network involved in the modulation of cell progression of ECa cells. Overall, EIF3J-AS1 may exhibit an oncogenic function in ECa via acting as a sponge for miR-373-3p to up-regulate AKT1 mRNA level, and may serve as a potential therapeutic target and a prognostic biomarker for ECa patients.

Long non‑coding RNA NR2F1‑AS1 facilitates the osteosarcoma cell malignant phenotype via the miR‑485‑5p/miR‑218‑5p/BIRC5 axis

Long non-coding RNA (lncRNA) NR2F1 antisense RNA 1 (NR2F1-AS1) has been reported to be an oncogene in several cancer types, including osteosarcoma (OS). However, the underlying fundamental molecular mechanism of NR2F1-AS1 in OS remains largely unknown, which the present study aimed to elucidate. The present study demonstrated that NR2F1-AS1 expression is markedly increased in OS, and NR2F1-AS1 was shown to exert oncogenic functions in OS. Further molecular mechanistic studies revealed that microRNA (miR)-485-5p and miR-218-5p were direct targets of NR2F1-AS1. More importantly, miR-485-5p and miR-218-5p exhibited low expression levels and were negatively correlated with NR2F1-AS1 expression in OS tissues. It was then identified that baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5) was a direct target of miR-485-5p and miR-218-5p in OS cells. Furthermore, a series of experiments suggested that NR2F1-AS1 affects the proliferation, migration, invasion and apoptosis of OS cells by regulating BIRC5. Finally, it was revealed that silencing of NR2F1-AS1 repressed the OS cell malignant phenotype by binding with miR-485-5p and miR-218-5p, and then downregulating BIRC5 expression, which suggests that the NR2F1-AS1/miR-485-5p/miR-218-5p/BIRC5 axis could be a potential target for treating OS.

Effect of Different Expression of Immune-Related lncRNA on Colon Adenocarcinoma and Its Relation to Prognosis

Objective

To explore the expression of immune-related lncRNAs in colon adenocarcinoma and find out the effect on how these lncRNAs influence the development and prognosis of colon adenocarcinoma.

Method

Transcriptome data of colon adenocarcinoma from The Cancer Genome Atlas (TCGA) were downloaded, and gene sets “IMMUNE RESPONSE” and “IMMUNE SYSTEM PROCESS” were sought from the Molecular Signatures Database (MSigDB). The expression of immune-related genes was extracted that were immune-related mRNAs. Then, the immune-related lncRNAs were sought out by utilizing of the above data. Clinical traits were combined with immune-related lncRNAs, so that prognostic-related lncRNAs were identified by Cox regression. Multivariate Cox regression was built to calculate risk scores. Relationships between clinical traits and immune-related lncRNAs were also calculated.

Result

A total of 480 colorectal adenocarcinoma patients and 41 normal control patients' transcriptome sequencing data of tissue samples were obtained from TCGA database. 918 immune-related lncRNAs were screened. Cox regression showed that 34 immune-related lncRNAs were associated with colon adenocarcinoma prognosis. Seven lncRNAs were independent risk factors.

Conclusion

This study revealed that some lncRNAs can affect the development and prognosis of colon adenocarcinoma. It may provide new theory evidence of molecular mechanism for the future research and molecular targeted therapy of colon adenocarcinoma.