Overexpression LINC01082 suppresses the proliferation, migration and invasion of colon cancer

LncRNA EBLN3P Accelerates Cell Proliferation and Invasion of Colon Cancer through Modulating the miR-519d-3p/ZFP91 Axis

Purpose: The study aims to explore the roles and underlying mechanisms of long noncoding RNAs endogenous bornavirus-like nucleoprotein (lncRNA EBLN3P) in colon cancer, emphasizing the potential impact of these insights on advancing colon cancer treatment strategies. By shedding light on lncRNA EBLN3P's involvement, this research could contribute to the development of novel therapeutic approaches, enhancing the efficacy of interventions for colon cancer patients. Methods: We employed quantitative reverse transcription polymerase chain reaction to assess the levels of lncRNA EBLN3P, zinc finger protein (ZFP91), and miR-519d-3p, alongside CCK-8 and EdU assays for cell proliferation, flow cytometry for apoptosis, and Transwell and wound healing assays for migration and invasion. The in vivo function of lncRNA EBLN3P was investigated through a xenograft model, and protein levels were evaluated via Western blot analysis. Results: LncRNA EBLN3P was found to be upregulated in colon cancer tissues and cells, promoting cell proliferation and metastasis while inhibiting apoptosis. Downregulation of lncRNA EBLN3P reduced tumor size, volume, and weight in a mouse model. MiR-519d-3p, which negatively interacts with lncRNA EBLN3P, was found to be downregulated in colon cancer tissues and cell lines. Its upregulation hindered cancer cell proliferation and metastasis while enhancing apoptosis. ZFP91, a binding partner of miR-519d-3p, was upregulated in colon cancer and inversely related to miR-519d-3p levels. Rescue experiments indicated that the effects of lncRNA EBLN3P silencing could be reversed by miR-519d-3p suppression, but were mitigated by ZFP91 downregulation. Conclusion: LncRNA EBLN3P facilitates colon cancer progression via the miR-519d-3p/ZFP91 axis, presenting a novel understanding of lncRNA EBLN3P's role and offering potential therapeutic insights for colon cancer treatment. This study fills a critical gap by linking lncRNA EBLN3P with the miR-519d-3p/ZFP91 axis in the context of colon cancer, thereby broadening our understanding of the molecular mechanisms underlying colon cancer progression.

EH domain-containing protein 2 (EHD2): Overview, biological function, and therapeutic potential

EH domain-containing protein 2 (EHD2) is a member of the EHD protein family and is mainly located in the plasma membrane, but can also be found in the cytoplasm and endosomes. EHD2 is also a nuclear-cytoplasmic shuttle protein. After entering the cell nuclear, EHD2 acts as a corepressor of transcription to inhibit gene transcription. EHD2 regulates a series of biological processes. As a key regulator of endocytic transport, EHD2 is involved in the formation and maintenance of endosomal tubules and vesicles, which are critical for the intracellular transport of proteins and other substances. The N-terminal of EHD2 is attached to the cell membrane, while its C-terminal binds to the actin-binding protein. After binding, EHD2 connects with the actin cytoskeleton, forming the curvature of the membrane and promoting cell endocytosis. EHD2 is also associated with membrane protein trafficking and receptor signaling, as well as in glucose metabolism and lipid metabolism. In this review, we highlight the recent advances in the function of EHD2 in various cellular processes and its potential implications in human diseases such as cancer and metabolic disease. We also discussed the prospects for the future of EHD2. EHD2 has a broad prospect as a therapeutic target for a variety of diseases. Further research is needed to explore its mechanism, which could pave the way for the development of targeted treatments.

Silencing LY6D Expression Inhibits Colon Cancer in Xenograft Mice and Regulates Colon Cancer Stem Cells' Proliferation, Stemness, Invasion, and Apoptosis via the MAPK Pathway

This study explored the role of lymphocyte antigen 6 family member D (LY6D) in colon cancer stem cells' (CCSCs) proliferation and invasion. LY6D was knocked down using siRNA, and the down-regulation of LY6D was verified using Western blotting. After LY6D knockdown, CCSCs' proliferation, stemness, and invasion were suppressed, whereas apoptosis was increased. Gene Ontology (GO) enrichment analysis revealed that the differentially expressed genes (DEGs) between siLY6D and the negative control groups were significantly enriched in the cell-substrate adherens junction, focal adhesion, and cell-substrate junction terms. Meanwhile, the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that the DEGs were significantly enriched in the MAPK pathway. In addition, Western blotting results showed that pBRAF and pERK1/2, cascade kinases of the MAPK pathway, were significantly down-regulated after LY6D knockdown. In addition, nude mice xenograft experiments showed that the siLY6D treatment decreased tumor sizes and weights and improved tumor-bearing mice survival rates compared with the control group. In conclusion, these findings indicate that LY6D, which is highly expressed in CCSCs, is a key factor involved in tumor growth and development and might be a potential cancer marker and therapeutic target for colon cancer.

LINC01082 Inhibits Non-Small Cell Lung Cancer by Targeting the miR-543/TNRC6A Axis

Non-small cell lung cancer (NSCLC) accounts for over 80% of lung cancer cases and have poor clinical outcomes. Increasing number of lncRNAs are reported to be implicated in the carcinogenesis of NSCLC. Previous lncRNA-seq results showed that LINC01082 was under-expressed in several cancer types. In the current study, we focused on the role of LINC01082 in NSCLC development. An online bioinformatics tool was utilized to assess the expression profile of LINC01082, miR-543, and TNRC6A in NSCLC samples. RT-qPCR analysis was performed for evaluating LINC01082, TNRC6A and miR-543 expression in cells (NSCLC cells vs. normal lung cells). Impact of LINC01082 upregulation on cell proliferation in vitro was investigated by MTT and EdU experiments. Transwell assay was applied to analyze the migration and invasion of NSCLC cells. The cell apoptosis after plasmid transfection was detected by flow cytometry. The interactions among LINC01082, miR-543 and TNRC6A were measured by RNA pulldown and luciferase reporter assays. We showed that LINC01082 levels were downregulated in NSCLC samples and NSCLC cells. Overexpression of LINC01082 inhibited NSCLC cell proliferation, migration and invasion and strengthened cell apoptosis. LINC01082 directly bound to miR-543, and miR-543 targeted TNRC6A. TNRC6A was downregulated and miR-543 was overexpressed in NSCLC cells. miR-543 inhibition suppressed malignant cellular behaviors. TNRC6A knockdown reversed the effects of LINC01082 on the malignant character of NSCLC cells. In conclusion, LINC01082 exerts an antioncogenic role in NSCLC via interaction with miR-543 to regulate TNRC6A expression.

WNT5A: a double-edged sword in colorectal cancer progression

The Wnt signaling pathway is known to play a crucial role in cancer, and WNT5A is a member of this pathway that binds to the Frizzled (FZD) and Receptor Tyrosine Kinase-Like Orphan Receptor (ROR) family members to activate non-canonical Wnt signaling pathways. The WNT5A pathway is involved in various cellular processes, such as proliferation, differentiation, migration, adhesion, and polarization. In the case of colorectal cancer (CRC), abnormal activation or inhibition of WNT5A signaling can lead to both oncogenic and antitumor effects. Moreover, WNT5A is associated with inflammation, metastasis, and altered metabolism in cancer cells. This article aims to discuss the molecular mechanisms and dual roles of WNT5A in CRC.

Long non-coding RNA CCL14-AS suppresses invasiveness and lymph node metastasis of colorectal cancer cells by regulating MEP1A

BACKGROUND

Long non-coding RNAs (lncRNAs) play important roles in the biology of colorectal cancer (CRC). There are several lncRNAs associated with invasion and metastasis have been characterized in CRC. However, studies focusing on the precise molecular mechanisms by which lncRNAs function in lymph node (LN) metastasis in CRC are still limited.

METHODS

In this study, by analyzing TCGA dataset, we identified that AC244100.2 (termed CCL14-AS), a novel lncRNA enriched in the cytoplasm, was negatively correlated with LN metastasis and unfavorable prognosis of CRC. In situ hybridization was used to examine CCL14-AS expression in clinical CRC tissues. Various functional experiments including migration assay and wound-healing assay were used to investigate the effects of CCL14-AS on CRC cells migration. The nude mice popliteal lymph node metastasis model assay further confirmed the effects of CCL14-AS in vivo.

RESULTS

CCL14-AS expression was significantly downregulated in CRC tissues compared to adjacent normal tissues. In addition, low CCL14-AS expression was correlated with advanced T classification, LN metastasis, distant metastasis, and shorter disease-free survival of CRC patients. Functionally, CCL14-AS overexpression inhibited the invasiveness of CRC cells in vitro and LN metastasis in nude mice. On the contrary, knockdown of CCL14-AS promoted the invasiveness and LN metastasis abilities of CRC cells. Mechanistically, CCL14-AS downregulated the expression of MEP1A via interacting with MEP1A mRNA and reduced its stability. Overexpression of MEP1A rescued the invasiveness and LN metastasis abilities in CCL14-AS-overexpressing CRC cells. Moreover, the expression levels of CCL14-AS was negatively correlated with that of MEP1A in CRC tissues.

CONCLUSIONS

We identified a novel lncRNA, CCL14-AS, as a potential tumor suppressor in CRC. Our findings supported a model in which the CCL14-AS/MEP1A axis serves as critical regulator in CRC progression, suggesting a novel biomarker and therapeutic target in advanced CRC.

Predicting prognosis and immunotherapy response among colorectal cancer patients based on a tumor immune microenvironment-related lncRNA signature

Long non-coding RNAs (lncRNAs) remodel the tumor immune microenvironment (TIME) by regulating the functions of tumor-infiltrating immune cells. It remains uncertain the way that TIME-related lncRNAs (TRLs) influence the prognosis and immunotherapy response of colorectal cancer (CRC). Aiming at providing survival and immunotherapy response predictions, a CRC TIME-related lncRNA signature (TRLs signature) was developed and the related potential regulatory mechanisms were explored with a comprehensive analysis on gene expression profiles from 97 immune cell lines, 61 CRC cell lines and 1807 CRC patients. Stratifying CRC patients with the TRLs signature, prolonged survival was observed in the low-risk group, while the patients in the high-risk group had significantly higher pro-tumor immune cells infiltration and higher immunotherapy response rate. Through the complex TRLs-mRNA regulation network, immunoregulation pathways and immunotherapy response pathways were found to be differently activated between the groups. In conclusion, the CRC TRLs signature is capable of making prognosis and immunotherapy response predictions, which may find application in stratifying patients for immunotherapy in the bedside.

Circ_0085315 promotes cell proliferation, invasion, and migration in colon cancer through miR-1200/MAP3K1 signaling pathway

Colon cancer (CC) is a common malignant tumor of the digestive tract. Circular RNAs (circRNAs) play important roles in the progression of CC. This study aimed to explore the role and mechanism of circRNA_0085315 in CC. In this study, we used qRT-PCR and Western blot assays to analyze the expressions of circRNA, miRNA, and mRNA as well as the expression of the related proteins. Luciferase reporter, RNA pull-down, and qRT-PCR assays were used to prove the relationship among circRNA, miRNA, and mRNA. CCK-8, colony formation, and transwell assays were used to perform the analysis of cell proliferation, migration, and invasion. Our results showed that the higher circRNA_0085315 expression led to the poorer prognosis of CC patients. The function of circRNA_0085315 as a ceRNA in competing with MAP3K1 mRNA to sponge miR-1200. CircRNA_0085315 sponged miR-1200 to promote cell proliferation, migration, and invasion and affected the expression of Ki67, MMP2, E-cadherin, and N-cadherin, but not circRNA_0085315-mut without the binding site of miR-1200. MAP3K1-overexpression or miR-1200 mimics prevented the suppression on the enhanced cell proliferation, migration, and invasion caused by circRNA_0085315-overexpression. circRNA_0085315 increased the phosphorylation levels of JNK, p38, and ERK1/2 by stimulating MAP3K1 up-regulation caused by miR-1200 inhibition. In conclusion, circRNA_0085315 serves as a ceRNA and promotes CC progression through the activation of the MAPK signaling pathway mediated via the miR-1200/MAP3K1 axis, suggesting that circRNA_0085315 may be a promising diagnostic and therapeutic target for CC.

The long non-coding RNA T cell leukemia homeobox 1 neighbor enhances signal transducer and activator of transcription 5A phosphorylation to promote colon cancer cell invasion, migration, and metastasis

Colon cancer is among the most prevalent gastrointestinal tumor types. The long noncoding RNA (lncRNA) T cell leukemia homeobox 1 neighbor (TLX1NB) is up-regulated in colorectal cancer (CRC). However, the functional role of this lncRNA in colon cancer remains unknown. In our study, we investigated the clinical significance of TLX1NB in colon cancer through bioinformatics analysis and explored its role in migration, invasion and metastasis of colon cancer cell with a series of experiments. Firstly, TLX1NB was up-regulated in colon cancer tissues and increased TLX1NB expression was significantly associated with advanced N stages. In wound healing assays and transwell assays, TLX1NB overexpression promoted HCT116 cell migration and invasion while TLX1NB knockdown inhibited SW620 cell migration and invasion. In vivo, TLX1NB knockdown suppressed pulmonary metastasis of SW620 cell and vimentin expression but increased E-cadherin expression. Then, TLX1NB overexpression enhanced signal transducer and activator of transcription 5A (STAT5A) phosphorylation and TLX1NB knockdown suppressed STAT5A phosphorylation. Moreover, the inhibition of STAT5A phosphorylation reversed TLX1NB overexpression-associated increase in HCT116 cell migratory and invasive activity. In conclusion, TLX1NB enhances STAT5A phosphorylation to promote colon cancer cell invasion, migration, and metastasis.

A novel immune-related lncRNA pair signature for prognostic prediction and immune response evaluation in gastric cancer: a bioinformatics and biological validation study

Background

Gastric cancer (GC), the most commonly diagnosed cancer worldwide with poor 5-year survival rate in advanced stages. Although immune-related and survival-related biomarkers, which typically comprise aberrantly expressed long non-coding RNAs (lncRNAs) and genes, have been identified, there are no reports of immune-related lncRNA pair (IRLP) signatures for GC.

Methods

In this study, we acquired lncRNA expression profiles from The Cancer Genome Atlas (TCGA) and used the least absolute shrinkage and selection operator (LASSO) Cox proportional hazards model (iteration = 1000) to develop a IRLP prognostic signature. The area under curve (AUC) was used to assess the prognosis predictive power. The multivariate Cox regression analysis was performed to identify whether this signature was an independent prognostic factor. The immune cell infiltration analysis was performed between the two risk groups. Last, molecular experiments were performed to explore LINC01082 is involved in the development of GC.

Results

We acquired lncRNA expression profiles and used the LASSO Cox model to develop an 18-IRLP signature with a strong prognostic predictive power. The 5-year AUC values of the training, validation, and overall TCGA datasets were 0.77, 0.86, and 0.80, respectively. The different prognostic outcomes between the high- and low-risk groups were determined using our 18-IRLP signature. Moreover, our 18-IRLP signature was an independent prognostic factor as per the multivariate Cox regression analysis, and showed better prognostic evaluation than the traditional TNM staging system as well as other clinical features. We also found differences in cancer-associated fibroblast and macrophage M2 infiltration and the expression of PD-L1, CTLA4, LAG3, and HLA were also observed between the two risk groups (P < 0.05). Analysis of biological functions revealed that target genes of the lncRNAs in the IRLP signature were enriched in focal adhesion and regulation of actin cytoskeleton. Finally, as one of significant candidates of IRLP signature, overexpression of LINC01082 suppressed the invasion ability of GC cells as well as PD-L1 expression profiles.

Conclusions

Our novel 18-IRLP signature provides new insights regarding immunological biomarkers, imparts a better understanding of the tumor immune microenvironment, and can be used for predicting prognosis and evaluating immune response in GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02493-2.

lncRNA FOXD3-AS1 promotes the progression of non-small cell lung cancer by regulating the miR-135a-5p/CDK6 axis

Long non-coding RNA (lncRNA) is essential to the development and progression of malignant human cancer. Growing evidence suggests that the lncRNA forkhead box D3 antisense 1 (FOXD3-AS1) is a crucial regulatory effector for multiple cancer types and is closely associated with poor prognosis. However, in most cases, the molecular mechanism underlying the role of FOXD3-AS1 in cancer development has not yet been fully elucidated. The present study focused on non-small cell lung cancer (NSCLC) in order to gain insight into how FOXD3-AS1 drives cancer progression. First, FOXD3-AS1 expression in NSCLC tissue samples was detected using reverse transcription-quantitative (RT-qPCR). Moreover, cell proliferation and apoptosis were determined using Cell Counting Kit-8 assays and flow cytometry, respectively. A luciferase reporter assay was then performed to determine whether there was a direct binding association between FOXD3-AS1 and microRNA (miR)-135a-5p. Lastly, a tumor subcutaneous xenograft model was established to examine the role of FOXD3-AS1 in tumor growth. FOXD3-AS1 was significantly overexpressed in NSCLC tissue samples and cell lines compared with normal tissue samples and cells. FOXD3-AS1 silencing expression significantly inhibited A549 and H1229 cell proliferation while inducing apoptosis compared with sh-NC group. The luciferase reporter assay demonstrated the direct binding interaction between FOXD3-AS1 and miR-135a-5p. Moreover, FOXD3-AS1 silencing led to the upregulation of miR-135a-5p in A549 and H1229 cells compared with sh-NC group. It was also demonstrated that miR-135a-5p could bind to the 3′ untranslated region of cyclin-dependent kinase 6 (CDK6) and negatively modulate its transcription. miR-135a-5p knockdown or CDK6 overexpression reversed the inhibition on cell proliferation and apoptosis following FOXD3-AS1 knockdown. Altogether, the present study suggests that FOXD3-AS1 sponges miR-135a-5p to promote cell proliferation and concomitantly inhibit apoptosis by regulating CDK6 expression in NSCLC cells.

Long non-coding RNA profile study identifies a metabolism-related signature for colorectal cancer

BACKGROUND

Heterogeneity in colorectal cancer (CRC) patients provides novel strategies in clinical decision-making. Identifying distinctive subgroups in patients can improve the screening of CRC and reduce the cost of tests. Metabolism-related long non-coding RNA (lncRNA) can help detection of tumorigenesis and development for CRC patients.

METHODS

RNA sequencing and clinical data of CRC patients which extracted and integrated from public databases including The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) were set as training cohort and validation cohort. Metabolism-related genes were acquired from Kyoto Encyclopedia of Genes and Genomes (KEGG) and the metabolism-related lncRNAs were filtered using correlation analysis. The risk score was calculated based on lncRNAs with prognostic value and verified through survival curve, receiver operating characteristic (ROC) curve and risk curve. Prognostic factors of CRC patients were also analyzed. Nomogram was constructed based on the results of cox regression analyses. The different immune status was observed in the single sample Gene Set Enrichment Analysis (ssGSEA).

RESULTS

The training cohort and the validation cohort enrolled 432 and 547 CRC patients respectively. A total of 23 metabolism-related lncRNAs with prognostic value were screened out and 10 of which were significantly differentially expressed between tumour and normal tissues. Finally, 8 lncRNAs were used to establish a risk score (DICER1-AS1, PCAT6, GAS5, PRR7-AS1, MCM3AP-AS1, GAS6-AS1, LINC01082 and ADIRF-AS1). Patients were divided into high-risk and low-risk groups according to the median of risk scores in training cohort and the survival curves indicated that the survival prognosis was significantly different. The area under curve (AUC) of the ROC curve in two cohorts were both greater than 0.6. The age, tumour stage and risk score were selected as independent factors and used to construct a nomogram to predict CRC patients' survival rate with the c-index of 0.806. The ssGSEA indicated that the risk score was associated with immune cells and functions.

CONCLUSIONS

Our systematic study established a metabolism-related lncRNA signature to predict outcomes of CRC patients which may contribute to individual prevention and treatment.

LncRNA ACTA2-AS1 suppress colon adenocarcinoma progression by sponging miR-4428 upregulation BCL2L11

BACKGROUND

Long non-coding RNA is considered to be essential to modulate the development and progression of human malignant cancers. And long non-coding RNA can act as crucial modulators by sponging the corresponding microRNA in tumorigenesis. We aimed to elucidate the function of ACTA2-AS1 and its molecular mechanism in colon adenocarcinoma.

MATERIALS AND METHODS

The expression of ACTA2-AS1, miR-4428 and BCL2L11 in colon adenocarcinoma tissues were detected via qRT-PCR. SW480 and HT29 cells were transfected with shRNA ACTA2-AS1, OE ACTA2-AS1, miRNA mimics of miR-4428, miR-4428 inhibitor, si-BCL2L11 and over-expression of si-BCL2L11. Cell proliferation, colony formation and apoptosis were respectively assessed using CCK-8 assay, colony assay and flow cytometry. Luciferase reporter assay was performed to verify the targets of ACTA2-AS1 and miR-4428. Tumor subcutaneous xenograft mode was constructed to explore tumor growth in vivo.

RESULTS

ACTA2-AS1 was obviously downregulated in human colon adenocarcinoma tissues and colon adenocarcinoma cell lines. Silence or over-expression of ACTA2-AS1 promoted or inhibited cell proliferation and colony formation abilities, and regulated apoptosis. The silence of ACTA2-AS1 resulted in the decrease of Bax and increase of Bal2, while restored in OE ACTA2-AS1 group when compared with the control transfected cells. In addition, luciferase reporter assay revealed that ACTA2-AS1 interacted with miR-4428 and suppressed its expression. miR-4428 could bind to 3' untranslated region of BCL2L11 and modulated the expression of BCL2L11 negatively. Knockdown of ACTA2-AS1 and over-expression of BCL2L11 reversed the biological function that ACTA2-AS1 mediated by knockdown ACTA2-AS1 alone.

CONCLUSION

Our data demonstrated that ACTA2-AS1 could suppress colon adenocarcinoma progression via sponging miR-4428 to regulate BCL2L11 expression.

Long noncoding RNAs: functions and mechanisms in colon cancer

Evidence indicates that long non-coding RNAs (lncRNAs) play a crucial role in the carcinogenesis and progression of a wide variety of human malignancies including colon cancer. In this review, we describe the functions and mechanisms of lncRNAs involved in colon oncogenesis, such as HOTAIR, PVT1, H19, MALAT1, SNHG1, SNHG7, SNHG15, TUG1, XIST, ROR and ZEB1-AS1. We summarize the roles of lncRNAs in regulating cell proliferation, cell apoptotic death, the cell cycle, cell migrative and invasive ability, epithelial-mesenchymal transition (EMT), cancer stem cells and drug resistance in colon cancer. In addition, we briefly highlight the functions of circRNAs in colon tumorigenesis and progression, including circPPP1R12A, circPIP5K1A, circCTIC1, circ_0001313, circRNA_104916 and circRNA-ACAP2. This review provides the rationale for anticancer therapy via modulation of lncRNAs and circular RNAs (circRNAs) in colon carcinoma.

Exploring the Roles of lncRNAs in GBM Pathophysiology and Their Therapeutic Potential

Glioblastoma (GBM) remains the most devastating primary central nervous system malignancy with a median survival of around 15 months. The past decades of research have not yielded significant advancements in the treatment of GBM. In that same time, a novel class of molecules, long non-coding RNAs (lncRNAs), has been found to play a multitude of roles in cancer and normal biology. The increased accessibility of next generation sequencing technologies and the advent of lncRNA-specific microarrays have facilitated the study of lncRNA etiology. Molecular and computational methods can be applied to predict lncRNA function. LncRNAs can serve as molecular decoys, scaffolds, super-enhancers, or repressors. These molecules can serve as phenotypic switches for GBM cells at the expression and/or epigenetic levels. LncRNAs can affect stemness/differentiation, proliferation, invasion, survival, DNA damage response, and chromatin dynamics. Aberrant expression of these transcripts may facilitate therapy resistance, leading to tumor recurrence. LncRNAs could serve as novel theragnostic or prognostic biomarkers in GBM and other cancers. RNA-based therapeutics may also be employed to target lncRNAs as a novel route of treatment for primary or recurrent GBM. In this review, we explore the roles of lncRNAs in GBM pathophysiology and posit their novel therapeutic potential for GBM.

LncRNA DSCAM-AS1 Promotes Colon Cancer Cells Proliferation and Migration via Regulating the miR-204/SOX4 Axis

Introduction

Long non-coding RNA (lncRNA) DSCAM-AS1 was reported to be aberrantly expressed and play pivotal roles in various human cancers. The aim of the present study was to investigate the expression and roles of DSCAM-AS1 in colon cancer (CC).

Methods

Quantitative real-time PCR (qRT-PCR) was used to detect the expression of DSCAM-AS1, miR-204 and the mRNA level of SOX4. Cell proliferation and cell cycle were analyzed by MTT assay and flow cytometry, respectively. Transwell assay was used for migration capacity detection. Luciferase activity assay was conducted to verify the direct binding of DSCAM-AS1 and miR-204 or miR-204 and SOX4. The protein expression of SOX4 was determined by Western blot. Kaplan–Meier curves were calculated and the Log rank test was performed for the survival data analysis.

Results

DSCAM-AS1 was significantly upregulated in CC and high expression of DSCAM-AS1 was associated with poor prognosis in patients with colon cancer. Knockdown of DSCAM-AS1 significantly suppressed CC cells proliferation and migration. In addition, DSCAM-AS acted as a molecular sponge for miR-204 and SOX4 was identified as a direct target of miR-204 in CC. Moreover, the rescue assay revealed that miR-204 inhibition partly abolished the effects of DSCAM-AS1 knockdown on CC cells proliferation, migration and SOX4 expression.

Discussion

The present study demonstrated that DSCAM-AS1 acted as an oncogenic lncRNA in CC progression by regulating miR-204/SOX4 axis and DSCAM-AS1 may serve as a novel therapeutic target in the treatment of colon cancer.

Long Noncoding RNA MALAT1 Promotes the Development of Colon Cancer by Regulating miR-101-3p/STC1 Axis

Purpose

Colon cancer (CC) is a leading cause of cancer-related deaths worldwide. This study aimed to clarify the effect of long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on CC progression and the potential mechanism.

Methods

CC cell lines HCT116 and HT29 were selected for functional analysis. The expression of MALAT1, microRNA (miR)-101-3p, and stanniocalcin 1 (STC1) in CC tissues and cells were measured by quantitative reverse transcription PCR (qRT-PCR). Cell proliferation, apoptosis, migration and invasion were measured by Cell Counting Kit-8 (CCK-8), flow cytometry, wound scratch and transwell assay, respectively. The target relationships (MALAT1 and miR-101-3p, miR-101-3p and STC1) were validated by dual-luciferase reporter and RNA pull-down assay.

Results

The expression of MALAT1 was elevated in CC tissues compared with adjacent normal tissues and was associated with lymph node metastasis, depth of invasion and tumor-node-metastasis (TNM) stage. Up-regulation of MALAT1 promoted the proliferation, migration, and invasion and inhibited the apoptosis of CC cells; while MALAT1 knockdown exhibited opposite results. MiR-101-3p was a target of MALAT1, which was negatively regulated by MALAT1. Silencing of miR-101-3p reverses the anti-tumor effect of MALAT1 knockdown on CC cells. STC1 was a target of miR-101-3p, which was negatively regulated by miR-101-3p. Silencing of STC1 reverses the tumor promoting effects of MALAT1 up-regulation and miR-101-3p down-regulation on CC cells.

Conclusion

MALAT1 may function as an oncogene in CC progression by affecting the miR-101-3p/STC1 axis, providing a hopeful therapeutic option for CC.

LncRNA LINC00662 promotes colon cancer tumor growth and metastasis by competitively binding with miR-340-5p to regulate CLDN8/IL22 co-expression and activating ERK signaling pathway

BACKGROUND

LncRNA LINC00662 is closely related to the occurrence and development of cancer. This study aims to explore the effect of LINC00662 on colon cancer tumor growth and metastasis and its molecular mechanism.

METHODS

CCK8, colony formation, transwell, scratch wound, TUNEL, flow cytometry, RT-PCR, western blotting and immunohistochemistry assays were used to detect the proliferation, apoptosis, invasion and migration of colon cancer cell and mRNA and protein expressions. Luciferase reporter and RNA pull down assays were used to detect the combination of LINC00662 and miR-340-5p or IL22 and the combination of miR-340-5p and CLDN8/IL22. Co-immunoprecipitation were used to detect the co-expression of CLDN8 and IL22 in colon cell lines. The targets of LINC00662 were predicated by Starbase v2.0. The target genes of miR-340-5p were predicated by miRDB and TargetScan. GO and KEGG enrichment analysis were performed by DAVID website.

RESULTS

LINC00662 was up-regulation in colon cancer tissues and cell lines. Univariate Cox regression analysis showed that the LINC00662 expression level was related to the poor prognosis. LINC00662-WT and miR-340-5p mimics co-transfection depressed luciferase activity and IL22/CLDN8-WT and miR-340-5p inhibitors co-transfection memorably motivated luciferase activity. LINC00662 overexpression promoted cell proliferation, invasion and migration, and inhibited cell apoptosis in colon cancer. In vivo xenograft studies in nude mice manifested that LINC00662 overexpression prominently accelerate tumor growth. There was an opposite reaction in the biological functions of colon cells and tumor growth between LINC00662 overexpression and LINC00662 inhibition in vitro and in vivo. The functions of miR-340-5p mimics regulating the biological functions of colon cells and tumor growth were consistent with those of LINC00662 inhibition. CLDN8 and IL22, as target genes of miR-340-5p, reversed the functions of LINC00662 affecting the biological functions of colon cells and the protein levels of Bax, Bcl-2, XIAP, VEGF, MMP-2, E-cadherin and N-cadherin. Co-immunoprecipitation experiments indicated that CLDN8 directly interact with IL22 in colon cell lines. LINC00662 regulated CLDN8 and IL22 expressions and the activation of ERK signaling pathway via targeting miR-340-5p.

CONCLUSION

LINC00662 overexpression promoted the occurrence and development of colon cancer by competitively binding with miR-340-5p to regulate CLDN8/IL22 co-expression and activating ERK signaling pathway.