Identification and development of long non-coding RNA-associated regulatory network in colorectal cancer

Three specific gut bacteria in the occurrence and development of colorectal cancer: a concerted effort

Colorectal cancer (CRC), which develops from the gradual evolution of tubular adenomas and serrated polyps in the colon and rectum, has a poor prognosis and a high mortality rate. In addition to genetics, lifestyle, and chronic diseases, intestinal integrity and microbiota (which facilitate digestion, metabolism, and immune regulation) could promote CRC development. For example, enterotoxigenic Bacteroides fragilis, genotoxic Escherichia coli (pks+ E. coli), and Fusobacterium nucleatum, members of the intestinal microbiota, are highly correlated in CRC. This review describes the roles and mechanisms of these three bacteria in CRC development. Their interaction during CRC initiation and progression has also been proposed. Our view is that in the precancerous stage of colorectal cancer, ETBF causes inflammation, leading to potential changes in intestinal ecology that may provide the basic conditions for pks+ E. coli colonization and induction of oncogenic mutations, when cancerous intestinal epithelial cells can further recruit F. nucleatum to colonise the lesion site and F. nucleatum may contribute to CRC advancement by primarily the development of cancer cells, stemization, and proliferation, which could create new and tailored preventive, screening and therapeutic interventions. However, there is the most dominant microbiota in each stage of CRC development, not neglecting the possibility that two or even all three bacteria could be engaged at any stage of the disease. The relationship between the associated gut microbiota and CRC development may provide important information for therapeutic strategies to assess the potential use of the associated gut microbiota in CRC studies, antibiotic therapy, and prevention strategies.

A review on the role of ADAMTS9-AS2 in different disorders

Recent decade has seen a tremendous progress in identification of the role of different long non-coding RNAs (lncRNAs) in human pathologies. ADAMTS9-AS2 is an example of lncRNAs with different roles in human disorders. It is mostly acknowledged as a tumor suppressor lncRNA in different types of cancers. However, it has been reported to be up-regulated in tongue squamous cell carcinoma, salivary adenoid cystic carcinoma and glioblastoma. Moreover, ADAMTS9-AS2 is possibly involved in the pathoetiology of pulpitis, acute ischemic stroke, type 2 diabetes and its complications. This lncRNA sponges miR-196b-5p, miR-223-3p, miR-130a-5p, miR-600, miR-223-3p, miR-27a-3p, miR-32, miR-143-3p, miR-143-3p and miR-182-5p in order to regulate downstream mRNAs. This review aims at summarization of the role of ADAMTS9-AS2 in different disorders with a particular focus on its diagnostic and prognostic values.

Construction of a Prognostic Model for Hypoxia-Related LncRNAs and Prediction of the Immune Landscape in the Digestive System Pan-Cancer

Digestive system pan-cancer is a general term for digestive system tumors including colorectal carcinoma (CRC), esophageal carcinoma (ESCA), stomach adenocarcinoma (STAD), and liver hepatocellular carcinoma (LIHC). Since the anatomical location, function and metabolism are closely related, there may be similarities in development and progression of these tumors. Hypoxia is the consequence of an imbalance between oxygen demand and supply, and intracellular hypoxia is associated with malignant progression, treatment resistance, and poor prognosis in tumors. Therefore, an urgent and challenging task is to investigate the molecular mechanisms associated with hypoxia in digestive system pan-cancer for the prognosis and treatment of digestive tract tumors. In this study, we identified 18 hypoxia-related lncRNAs (HRlncRNAs) by co-expression analysis between hypoxia genes and lncRNAs from digestive system pan-cancer. Six HRlncRNAs were then obtained using lasso regression and multivariate cox analysis to construct a prognostic model. Next, the Akaike information criterion (AIC) values for 3-year receiver operating curve (ROC) were counted to determine the cut-off point and establish an optimal model to distinguish between high- or low-risk groups among patients with digestive system pan-cancer. To evaluate the stability of the prognosis model, we validated it in terms of survival outcomes, clinicopathological stage, tumor-infiltrating immune cells, immune checkpoint inhibitors (ICIs) and anticancer drugs sensitivity. The results suggested that high- risk group had a worse prognosis and a more positive association with tumor-infiltrating immune cells such as B cells, cancer-associated fibroblasts, endothelial cells, monocytes, macrophages and bone marrow dendritic cells in digestive system pan-cancer. Immune checkpoint inhibitors (ICIs) related biomarkers discovered that high-risk group was positively correlated with high expression of HAVCR2 in digestive system pan-cancer. The anticancer drugs sensitivity analysis showed that the high-risk group was associated with the lower half-inhibitory centration (IC50) of Imatinib in digestive system pan-cancer. In conclusion, the prognostic model of HRlncRNAs showed a promising clinical prediction value and may provide a useful reference for the diagnosis and treatment of the digestive system tumors.

Construction of a lncRNA-associated competing endogenous RNA regulatory network after traumatic brain injury in mouse

Traumatic brain injury (TBI) is a major public health problem worldwide which causes high mortality and disability. Functioning as microRNA (miRNA) sponges, long non-coding RNA (lncRNA) regulates the expression of protein-coding genes in a competing endogenous RNA (ceRNA) network. However, the lncRNA-associated ceRNA in TBI remains unclear. In this study, we processed the raw SRR files of mice cortex samples of sham injury (n = 3) and TBI groups (n = 3) to count files. Then, the expression profiles of lncRNAs and mRNAs were identified, and 86 differentially expressed (DE) lncRNAs and 1201 DEmRNAs between sham and TBI groups were identified. The DEmRNAs were used to perform enrichment analyses. Next, a lncRNA-miRNA-mRNA regulatory ceRNA network was constructed. The network consisted of 23 mRNAs, 5 miRNAs and 2 lncRNAs. The expression alternations of the 5 miRNAs were validated via qRT-PCR. The subnetwork of hub lncRNA Neat1 was extracted. We identified a potential inflammatory associated regulatory axis: Neat1/miR-31-5p/Myd88 axis. The PPI network based on DEmRNA involved in ceRNA network was constructed PPI networks to identify the hub genes. Finally, DElncRNAs and DEmRNAs were selected randomly and validated by qRT-PCR. In conclusion, with the lncRNA-miRNA-mRNA ceRNA network provided above, we can improve our understanding of the regulatory mechanisms and interaction among lncRNAs, miRNAs and mRNAs in TBI process.

Competing Endogenous RNA in Colorectal Cancer: An Analysis for Colon, Rectum, and Rectosigmoid Junction

BACKGROUND

Colorectal cancer (CRC) is a heterogeneous cancer. Its treatment depends on its anatomical site and distinguishes between colon, rectum, and rectosigmoid junction cancer. This study aimed to identify diagnostic and prognostic biomarkers using networks of CRC-associated transcripts that can be built based on competing endogenous RNAs (ceRNA).

METHODS

RNA expression and clinical information data of patients with colon, rectum, and rectosigmoid junction cancer were obtained from The Cancer Genome Atlas (TCGA). The RNA expression profiles were assessed through bioinformatics analysis, and a ceRNA was constructed for each CRC site. A functional enrichment analysis was performed to assess the functional roles of the ceRNA networks in the prognosis of colon, rectum, and rectosigmoid junction cancer. Finally, to verify the ceRNA impact on prognosis, an overall survival analysis was performed.

RESULTS

The study identified various CRC site-specific prognosis biomarkers: hsa-miR-1271-5p, NRG1, hsa-miR-130a-3p, SNHG16, and hsa-miR-495-3p in the colon; E2F8 in the rectum and DMD and hsa-miR-130b-3p in the rectosigmoid junction. We also identified different biological pathways that highlight differences in CRC behavior at different anatomical sites, thus reinforcing the importance of correctly identifying the tumor site.

CONCLUSIONS

Several potential prognostic markers for colon, rectum, and rectosigmoid junction cancer were found. CeRNA networks could provide better understanding of the differences between, and common factors in, prognosis of colon, rectum, and rectosigmoid junction cancer.

Alternative Splicing Events in Tumor Immune Infiltration in Colorectal Cancer

Despite extensive research, the exact mechanisms involved in colorectal cancer (CRC) etiology and pathogenesis remain unclear. This study aimed to examine the correlation between tumor-associated alternative splicing (AS) events and tumor immune infiltration (TII) in CRC. We analyzed transcriptome profiling and clinical CRC data from The Cancer Genome Atlas (TCGA) database and lists of AS-related and immune-related signatures from the SpliceSeq and Innate databases, respectively to develop and validate a risk model of differential AS events and subsequently a TII risk model. We then conducted a two-factor survival analysis to study the association between TII and AS risk and evaluated the associations between immune signatures and six types of immune cells based on the TIMER database. Subsequently, we studied the distribution of six types of TII cells in high- and low-risk groups for seven AS events and in total. We obtained the profiles of AS events/genes for 484 patients, which included 473 CRC tumor samples and 41 corresponding normal samples, and detected 22581 AS events in 8122 genes. Exon Skip (ES) (8446) and Mutually Exclusive Exons (ME) (74) exhibited the most and fewest AS events, respectively. We then classified the 433 patients with CRC into low-risk (n = 217) and high-risk (n = 216) groups based on the median risk score in different AS events. Compared with patients with low-risk scores (mortality = 11.8%), patients with high-risk scores were associated with poor overall survival (mortality = 27.6%). The risk score, cancer stage, and pathological stage (T, M, and N) were closely correlated with prognosis in patients with CRC (P < 0.001). We identified 6479 differentially expressed genes from the transcriptome profiles of CRC and intersected 468 differential immune-related signatures. High-AS-risk and high-TII-risk predicted a poor prognosis in CRC. Different AS types were associated with different TII risk characteristics. Alternate Acceptor site (AA) and Alternate Promoter (AP) events directly affected the concentration of CD4T cells, and the level of CD8T cells was closely correlated with Alternate Terminator (AT) and Exon Skip (ES) events. Thus, the concentration of CD4T and CD8T cells in the CRC immune microenvironment was not specifically modulated by AS. However, B cell, dendritic cell, macrophage, and neutrophilic cell levels were strongly correlated with AS events. These results indicate adverse associations between AS event risk levels and immune cell infiltration density. Taken together, our findings show a clear association between tumor-associated alternative splicing and immune cell infiltration events and patient outcome and could form a basis for the identification of novel markers and therapeutic targets for CRC and other cancers in the future.

LINC00665 activates Wnt/β-catenin signaling pathway to facilitate tumor progression of colorectal cancer via upregulating CTNNB1

Background LINC00665 is a newly identified oncogene, which has been reported to be oncogene in various cancers. Nevertheless, its role in the progression of colorectal cancer (CRC) remains obscure to the extent. This study aimed at exploring the role and mechanism of LINC00665 in CRC progression. Materials and methods RNA and protein expression were detected via qRT-PCR and western blot. Functional assays were conducted to investigate the role of LINC00665 in the CRC cellular processes. TOP/FOP assay was performed to detect the activity of Wnt/β-catenin signaling pathway. Mechanism investigations were carried out to explore the regulatory relationship among genes. Results LINC00665 was overtly expressed in CRC cell lines at high levels. Functionally, silencing of LINC00665 could curb in vitro CRC cell growth, migration and invasion, while stimulating cell apoptosis. Mechanically, LINC00665 sponged miR-214-3p to up-regulate CTNNB1 expression, consequently activating Wnt/β-catenin signaling pathway. Furthermore, LINC00665 could bind to U2AF2 and enhance the association between U2AF2 and CTNNB1, increasing the stability of CTNNB1. CTNNB1 overexpression could reverse the suppressive effects of LINC00665 downregulation. Conclusion LINC00665 stimulates CRC progression through the activation of Wnt/β-catenin signaling pathway, which hopefully might be a therapeutic target for CRC.

Construction of competitive endogenous RNA network reveals regulatory role of long non-coding RNAs in intracranial aneurysm

BACKGROUND

Rupture of intracranial aneurysm (IA) is the main cause of devastating subarachnoid hemorrhage, which urges our understanding of the pathogenesis and regulatory mechanisms of IA. However, the regulatory roles of long non-coding RNAs (lncRNAs) in IA is less known.

RESULTS

We processed the raw SRR files of 12 superficial temporal artery (STA) samples and 6 IA samples to count files. Then the differentially expressed (DE) mRNAs, miRNAs, and lncRNAs between STAs and IAs were identified. The enrichment analyses were performed using DEmRNAs. Next, a lncRNA-miRNA-mRNA regulatory network was constructed using integrated bioinformatics analysis. In summary, 341 DElncRNAs, 234 DEmiRNAs, and 2914 DEmRNAs between the STA and IA. The lncRNA-miRNA-mRNA regulatory network of IA contains 91 nodes and 146 edges. The subnetwork of hub lncRNA PVT1 was extracted. The expression level of PVT1 was positively correlated with a majority of the mRNAs in its subnetwork. Moreover, we found that several mRNAs (CCND1, HIF1A, E2F1, CDKN1A, VEGFA, COL1A1 and COL5A2) in the PVT1 subnetwork served as essential components in the PI3K-Akt signaling pathway, and that some of the non-coding RNAs (ncRNAs) (PVT1, HOTAIR, hsa-miR-17, hsa-miR-142, hsa-miR-383 and hsa-miR-193b) interacted with these mRNAs.

CONCLUSION

Our annotations noting ncRNA's role in the pathway may uncover novel regulatory mechanisms of ncRNAs and mRNAs in IA. These findings provide significant insights into the lncRNA regulatory network in IA.

Exosome-derived long non-coding RNA ADAMTS9-AS2 suppresses progression of oral submucous fibrosis via AKT signalling pathway

Oral submucosal fibrosis (OSF) is one of the pre‐cancerous lesions of oral squamous cell carcinoma (OSCC). Its malignant rate is increasing, but the mechanism of malignancy is not clear. We previously have elucidated the long non‐coding RNA (lncRNA) expression profile during OSF progression at the genome‐wide level. However, the role of lncRNA ADAMTS9‐AS2 in OSF progression via extracellular communication remains unclear. lncRNA ADAMTS9‐AS2 is down‐regulated in OSCC tissues compared with OSF and normal mucous tissues. Low ADAMTS9‐AS2 expression is associated with poor overall survival. ADAMTS9‐AS2 is frequently methylated in OSCC tissues, but not in normal oral mucous and OSF tissues, suggesting tumour‐specific methylation. Functional studies reveal that exosomal ADAMTS9‐AS2 suppresses OSCC cell growth, migration and invasion in vitro. Mechanistically, exosomal ADAMTS9‐AS2 inhibits AKT signalling pathway and regulates epithelial‐mesenchymal transition markers. Through profiling miRNA expression profile regulated by exosomal ADAMTS9‐AS2, significantly enriched pathways include metabolic pathway, PI3K‐Akt signalling pathway and pathways in cancer, indicating that exosomal ADAMTS9‐AS2 exerts its functions through interacting with miRNAs during OSF progression. Thus, our findings highlight the crucial role of ADAMTS9‐AS2 in the cell microenvironment during OSF carcinogenesis, which is expected to become a marker for early diagnosis of OSCC.

Identification and Development of Long Non-coding RNA Associated Regulatory Network in Pancreatic Adenocarcinoma

Background and Aims

Pancreatic adenocarcinoma (PAAD) is the most lethal cancer type around the world. With the in-depth exploration of the function of long non‐coding RNAs (lncRNAs), the competing endogenous RNA (ceRNA) mechanism has shown its potential to partially reveal the pathogenesis of PAAD. This study aimed to construct a lncRNA‐associated ceRNA network and explore ceRNA regulatory axes with experimental and prognostic value in PAAD.

Methods

First, we applied differential expression analysis in the TCGA_PAAD dataset. Then, interaction analysis and survival analysis in multiple RNA interaction databases were conducted to construct a ceRNA network. Finally, a potential regulatory axis was validated using clinical samples and cell lines by quantitative realtime PCR (qRT‐PCR).

Results

A ceRNA network comprising 13 lncRNAs, 96 miRNAs, and 30 mRNAs was successfully constructed. Survival analysis further narrowed this network to five lncRNAs, three miRNAs, and seven mRNAs, which were significantly associated with patients’ overall survival. A potential regulatory axis CASC8-miR-129-5p-TOB1 was further experimentally validated. The expression of these genes was associated with clinicopathological factors and their expression trend was consistent with ceRNA mechanism. Specifically, knockdown of lncRNA-CASC8 led to the overexpression of miR-129-5p and down-regulation of TOB1, while overexpression of CASC8 showed opposite effects.

Conclusion

This novel ceRNA regulatory network could provide new insight into the pathogenesis of PAAD. The new regulatory axis CASC8-miR-129-5p-TOB1 might serve as a potential therapeutic target for patients.

Transcriptome and Gene Fusion Analysis of Synchronous Lesions Reveals lncMRPS31P5 as a Novel Transcript Involved in Colorectal Cancer

Fusion genes and epigenetic regulators (i.e., miRNAs and long non-coding RNAs) constitute essential pieces of the puzzle of the tumor genomic landscape, in particular in mechanisms behind the adenoma-to-carcinoma progression of colorectal cancer (CRC). In this work, we aimed to identify molecular signatures of the different steps of sporadic CRC development in eleven patients, of which synchronous samples of adenomas, tumors, and normal tissues were analyzed by RNA-Seq. At a functional level, tumors and adenomas were all characterized by increased activity of the cell cycle, cell development, cell growth, and biological proliferation functions. In contrast, organic survival and apoptosis-related functions were inhibited both in tumors and adenomas at different levels. At a molecular level, we found that three individuals shared a tumor-specific fusion named MRPS31-SUGT1, generated through an intra-chromosomal translocation on chromosome 13, whose sequence resulted in being 100% identical to the long non-coding RNA (lncRNA) MRPS31P5. Our analyses suggest that MRPS31P5 could take part to a competitive endogenous (ce)RNA network by acting as a miRNA sponge or/and as an interactor of other mRNAs, and thus it may be an important gene expression regulatory factor and could be used as a potential biomarker for the detection of early CRC events.

LncRNA ADAMTS9-AS2 in osteosarcoma inhibits cell proliferation and enhances paclitaxel sensitivity by suppressing microRNA-130a-5p

Introduction:

Long noncoding RNA ADAMTS9-AS2 (lncRNA ADAMTS9-AS2) has critical function in tumor growth and drug resistance of various cancers. However, the role and mechanism of lncRNA ADAMTS9-AS2 in osteosarcoma (OS) is still unclear.

Methods:

The expression of lncRNA ADAMTS9-AS2 and MicroRNAs-130a-5p (miR-130a-5p) was detected by real-time polymerase chain reaction (RT-qPCR) experiment. In addition, we used the plasmids transfection to construct the lncRNA ADAMTS9-AS2 overexpressed OS cell lines. Subsequently, the cell proliferation ability and the sensitivity to paclitaxel (PTX) in OS cells upon up-regulating lncRNA ADAMTS9-AS2 expression were analyzed via CCK-8 assay, while Western blotting experiment was performed to detect the regulatory mechanism.

Results:

We found that lncRNA ADAMTS9-AS2 was down-regulated in OS tissues, and the OS patients with lncRNA ADAMTS9-AS2 downexprssion were usually accompanied with a poor prognosis. Subsequently, we discovered that up-regulation of lncRNA ADAMTS9-AS2 inhibited cell proliferation and increased the sensitivity to PTX in OS cells. Interestingly, the Western blot results showed that overexpression of lncRNA ADAMTS9-AS2 could lead to PTEN expression increased, with PI3K and p-AKT expression decreased, indicating that lncRNA ADAMTS9-AS2 could increase the OS cell sensitivity to PTX via regulating PTEN-PI3K/AKT pathway. Furthermore, we identified MicroRNAs-130a-5p (miR-130a-5p) as the downstream target gene of lncRNA ADAMTS9-AS2, which was further confirmed by the luciferase reporter assay. More importantly, our data revealed that miR-130a-5p mimics could partly reverse the influence on cell proliferation and drug sensitivity induced by lncRNA ADAMTS9-AS2 overexpression.

Conclusion:

LncRNA ADAMTS9-AS2 exerts its anti-carcinogenesis function by sponging miR-130a-5p, which might be a new therapeutic target for OS treatment.

Multi-omics analysis to identify driving factors in colorectal cancer

Aim: We aim to identify driving genes of colorectal cancer (CRC) through multi-omics analysis. Materials & methods: We downloaded multi-omics data of CRC from The Cancer Genome Atlas dataset. Integrative analysis of single-nucleotide variants, copy number variations, DNA methylation and differentially expressed genes identified candidate genes that carry CRC risk. Kernal genes were extracted from the weighted gene co-expression network analysis. A competing endogenous RNA network composed of CRC-related genes was constructed. Biological roles of genes were further investigated in vitro. Results: We identified LRRC26 and REP15 as novel prognosis-related driving genes for CRC. LRRC26 hindered tumorigenesis of CRC in vitro. Conclusion: Our study identified novel driving genes and may provide new insights into the molecular mechanisms of CRC.

MicroRNA hsa-mir-3923 serves as a diagnostic and prognostic biomarker for gastric carcinoma

Gastric carcinoma (GC) refers to a common digestive system disease that exhibits a very high incidence. MicroRNA hsa-mir-3923 belongs to a type of miRNA, of which the function has been merely investigated in breast, pancreatic cancers and pre-neoplasic stages of gastric cancer. It has not been studied or reported in gastric carcinoma, so the relationship between gastric hsa-mir-3923 expression and the clinics feature and pathology of GC cases was examined. This study employed data mining for analyzing gastric carcinoma data in The Cancer Genome Atlas database. A Chi squared test was performed for assessing the relations of hsa-mir-3923 expression with clinics-related and pathology-regulated variables. This study conducted the assessment of the role of hsa-mir-3923 in prognostic process using Kaplan-Meier curves, Receiver operating characteristic (ROC) analysis and proportional hazards model (Cox) study. With the use of Gene Expression Omnibus, this study carried out gene set enrichment analysis (GSEA). In the meantime, the common miRNA database was compared to predict potential target genes; as revealed by co-expression analysis, a regulatory network probably existed, containing hsa-mir-3923. For the analysis of the most tightly associated cytological behavior and pathway in GC, this study adopted the databases for Annotation, Visualization and Integrated Discovery (David) and KO-Based Annotation System (KOBAS). Cytoscape, R and STRING were employed for mapping probable regulatory networks displaying relations to hsa-mir-3923. Lastly, we obtained 69 genes most tightly associated with hsa-mir-3923 and described their relationship with Circos plot. As revealed from the results, hsa-mir-3923 displayed up-regulation in gastric carcinoma, and it displayed associations with vital status, N stage and histologic grade when being expressed. The predicted results of miRNA target genes suggested that there may be a close relationship between 66 genes and hsa-mir-3923 in gastric cancer. As indicated from co-expression data, a small regulating network of 4 genes probably existed. Our results elucidated that hsa-mir-3923 high-expression reveals poor prognosis of GC patients.

Two precision medicine predictive tools for six malignant solid tumors: from gene-based research to clinical application

Background

The current study aimed to construct competing endogenous RNA (ceRNA) regulation network and develop two precision medicine predictive tools for colorectal cancer (CRC).

Methods

Differentially expressed (DE) analyses were performed between CRC tissues and normal tissues. A ceRNA regulation network was constructed based on DElncRNAs, DEmiRNAs, and DEmRNAs.

Results

Fifteen mRNAs (ENDOU, MFN2, FASLG, SHOC2, VEGFA, ZFPM2, HOXC6, KLK10, DDIT4, LPGAT1, BEX4, DENND5B, PHF20L1, HSP90B1, and PSPC1) were identified as prognostic biomarkers for CRC by multivariate Cox regression. Then a Fifteen-mRNA signature was developed to predict overall survival for CRC patients. Concordance indexes were 0.817, 0.838, and 0.825 for 1-, 2- and 3-year overall survival. Patients with high risk scores have worse OS compared with patients with low risk scores.

Conclusion

The current study provided deeper understanding of prognosis-related ceRNA regulatory network for CRC. Two precision medicine predictive tools named Smart Cancer Survival Predictive System and Gene Survival Analysis Screen System were constructed for CRC. These two precision medicine predictive tools can provide valuable precious individual mortality risk prediction before surgery and improve the individualized treatment decision-making.

Exosomal lncRNA HNF1A-AS1 affects cisplatin resistance in cervical cancer cells through regulating microRNA-34b/TUFT1 axis

Background

There is growing evidence of the role of long non-coding RNAs (lncRNAs) in cervical cancer (CC). The objective was to discuss whether exosomal lncRNA HNF1A-AS1 impacted drug resistance in CC via binding to microRNA-34b (miR-34b) and regulating TUFT1 expression.

Methods

The expression of HNF1A-AS1 in normal cervical epithelial cells, cisplatin (DDP)-sensitive cell line (HeLa/S) and DDP-resistant cell line (HeLa/DDP) cells were detected. HeLa/S and HeLa/DDP cells were interfered with HNF1A-AS1 to determine IC₅₀, proliferation, colony formation and apoptosis of CC cells. The exosomes were isolated and identified. Subcellular localization of HNF1A-AS1, expression of miR-34b and TUFT1 in receptor cells were also verified. The binding site between HNF1A-AS1 and miR-34b, together with miR-34b and TUFT1 were confirmed. Tumorigenic ability of cells in nude mice was also detected.

Results

HNF1A-AS1 was upregulated in DDP-resistant cell line HeLa/DDP. Silencing HNF1A-AS1 suppressed CC cell proliferation and promoted its apoptosis. HNF1A-AS1 was found to act as a competing endogenous RNA (ceRNA) of miR-34b to promote the expression of TUFT1. Exosomes shuttled HNF1A-AS1 promoted the proliferation and drug resistance of CC cells and inhibited their apoptosis by upregulating the expression of TUFT1 and downregulating miR-34b. Furthermore, suppressed exosomal HNF1A-AS1 in combination with DDP inhibited tumor growth in nude mice.

Conclusion

Our study provides evidence that CC-secreted exosomes carrying HNF1A-AS1 as a ceRNA of miR-34b to promote the expression of TUFT1, thereby promoting the DDP resistance in CC cells.

LncRNA PART1 regulates colorectal cancer via targeting miR-150-5p/miR-520h/CTNNB1 and activating Wnt/β-catenin pathway

Numerous studies have reported that lncRNAs could play a significant role in carcinogenesis. PART1, as an identified lncRNA, was an oncogene in several cancers. However, the underling mechanism of PART1 regulating colorectal cancer remains unknown. qRT-PCR was used to measure relevant RNAs expression. CCK8 and colony formation were combined to evaluate cell proliferation. Tunel and flow cytometry were performed to access cell apoptosis. Wound healing and Transwell assay testified cell invasion and migration ability. Relevant protein expression level was measured via Western blot assay. TOP/FOP luciferase assay determined the activity of Wnt/β-catenin pathway. According to experiment findings, PART1 was up-regulated in CRC tissues and cell lines. Inhibition of PART1 hindered CRC cell proliferation, invasion and migration, while promoting CRC cell apoptosis. Experiments in vivo also validated this result. Mechanistically, PART1 sponged miR-150-5p/miR-520 h to up-regulate CTNNB1, thus activating Wnt/β-catenin pathway in CRC. In summary, PART1 could up-regulate CTNNB1 via sponging miR-150-5p/miR-520 h.

Prognostic lncRNAs, miRNAs, and mRNAs Form a Competing Endogenous RNA Network in Colon Cancer

Purpose: To develop a multi-RNA-based model to provide survival risk prediction for colon cancer by constructing a competing endogenous RNAs (ceRNAs) network.

Methods: The prognostic information and expression of the lncRNAs, miRNAs, and mRNAs in colon cancer specimens from The Cancer Genome Atlas (TCGA) were assessed. Constructing prognostic models used the differentially expressed RNAs. Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses and Gene Ontology were used to identify the functional role of the ceRNA network in the prognosis of colon cancer.

Results: Five lncRNAs (AC007384.1, AC002511.1, AC012640.1, C17orf82, and AP001619.1), 8 miRNAs (hsa-mir-141, hsa-mir-150, hsa-mir-375, hsa-mir-96, hsa-mir-107, hsa-mir-106a, hsa-mir-200a, and hsa-mir-1271), and 5 mRNAs (BDNF, KLF4, SESN2, SMOC1, and TRIB3) were highly correlated with tumor status and tumor stage. Three prognostic models based on the 5 lncRNAs, 8 miRNAs, and 5 mRNAs were constructed. The prognostic ability was 0.850 for the lncRNA-based model, 0.811 for the miRNA-based model, and 0.770 for the mRNA-based model. Patients with high-risk scores revealed worse overall survival. The KEGG pathways were significantly enriched in the “neuroactive ligand-receptor interaction.”

Conclusion: This study identified several potential prognostic biomarkers to construct a multi-RNA-based prognostic model for colon cancer.

Identification and development of long non-coding RNA-associated regulatory network in colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer‐associated death globally. Long non‐coding RNAs (lncRNAs) have been identified as micro RNA (miRNA) sponges in a competing endogenous RNA (ceRNA) network and are involved in the regulation of mRNA expression. This study aims to construct a lncRNA‐associated ceRNA network and investigate the prognostic biomarkers in CRC. A total of 38 differentially expressed (DE) lncRNAs, 23 DEmiRNAs and 27 DEmRNAs were identified by analysing the expression profiles of CRC obtained from The Cancer Genome Atlas (TCGA). These RNAs were chosen to develop a ceRNA regulatory network of CRC, which comprised 125 edges. Survival analysis showed that four lncRNAs, six miRNAs and five mRNAs were significantly associated with overall survival. A potential regulatory axis of ADAMTS9‐AS2/miR‐32/PHLPP2 was identified from the network. Experimental validation was performed using clinical samples by quantitative real‐time PCR (qRT‐PCR), which showed that expression of the genes in the axis was associated with clinicopathological features and the correlation among them perfectly conformed to the ‘ceRNA theory’. Overexpression of ADAMTS9‐AS2 in colon cancer cell lines significantly inhibited the miR‐32 expression and promoted PHLPP2 expression, while ADAMTS9‐AS2 knockdown had the opposite effects. The constructed novel ceRNA network may provide a comprehensive understanding of the mechanisms of CRC carcinogenesis. The ADAMTS9‐AS2/miR‐32/PHLPP2 regulatory axis may serve as a potential therapeutic target for CRC.