LINC00707 promotes cell proliferation and invasion of colorectal cancer via miR-206/FMNL2 axis

Notch-associated lncRNAs profiling circuiting epigenetic modification in colorectal cancer

Background

Colorectal cancer (CRC) is one of the most prevalent digestive cancers, ranking the 2nd cause of cancer-related fatality worldwide. The worldwide burden of CRC is predicted to rise by 60% by 2030. Environmental factors drive, first, inflammation and hence, cancer incidence increase.

Main

The Notch-signaling system is an evolutionarily conserved cascade, has role in the biological normal developmental processes as well as malignancies. Long non-coding RNAs (LncRNAs) have become major contributors in the advancement of cancer by serving as signal pathways regulators. They can control gene expression through post-translational changes, interactions with micro-RNAs or down-stream effector proteins. Recent emerging evidence has emphasized the role of lncRNAs in controlling Notch-signaling activity, regulating development of several cancers including CRC.

Conclusion

Notch-associated lncRNAs might be useful prognostic biomarkers or promising potential therapeutic targets for CRC treatment.

Therefore, here-in we will focus on the role of “Notch-associated lncRNAs in CRC” highlighting “the impact of Notch-associated lncRNAs as player for cancer induction and/or progression.”

Graphical Abstract

LINC00707 Promotes Cell Proliferation in Cervical Cancer via the miR-374c-5p/SDC4 Axis

Cervical cancer (CC) is the second main reason of cancer-related deaths in women around the world. Long intergenic nonprotein coding RNA 707, which is known as LINC00707, has been elucidated to facilitate the progression of multifarious tumors, but how it may exert functions in CC has not been elucidated yet. By using quantitative real-time RT-PCR (RT-qPCR), we identified the expression pattern LINC00707 may possess in CC. Loss-of-function assays including Cell Counting Kit-8 (CCK-8), colony formation, and transferase-mediated dUTP nick-end labeling (TUNEL) assays were taken to verify the effects of LINC00707 inhibition on CC cell proliferation and apoptosis. The downstream RNAs were selected through bioinformatics prediction, and their interaction with LINC00707 was verified through mechanism assays including the luciferase reporter assay, RNA pull-down assay, and RNA immunoprecipitation (RIP) assay. According to results, LINC00707 was upregulated in CC cells, and LINC00707 insufficiency inhibited cell proliferation while facilitating cell apoptosis. MicroRNA (miRNA) miR-374c-5p interacted with LINC00707, and syndecan-4 (SDC4) was verified to be the downstream target gene. Data of rescue assays proved that LINC00707 could promote CC cell malignancy via the miR-374c-5p/SDC4 axis, which revealed a potential treatment option for CC.

Upregulated Linc01836 in Serum Promisingly Serving as a Diagnostic and Prognostic Biomarker for Colorectal Cancer

Objectives: Colorectal cancer (CRC) is a common carcinoma of the gastrointestinal tract with high incidence and mortality worldwide. Studies have shown that long noncoding RNAs (lncRNAs) play important roles in CRC. Our purpose is to investigate the potential of serum Linc01836 as a diagnostic and prognostic marker in CRC.

Methods: We evaluated the expression of Linc01836 via quantitative real-time polymerase chain reaction (qRT-PCR). The serum CEA, CA19-9, Cyfra21-1, and CA72-4 concentrations were measured by Architect I4000 SR. Receiver operating characteristic (ROC) curves were plotted to estimate the diagnostic value in CRC. Relationship between serum Linc01836 expression and clinicopathological characteristics of CRC cases was analyzed via chi-square test. The underlying mechanism of Linc01836 on the development and prognosis in CRC was predicted by bioinformatic analysis.

Results: The method of qRT-PCR for Linc01836 detection was confirmed with high precision and specificity. Serum Linc01836 expression in CRC patients was significantly higher than that in healthy donors (p < 0.0001) and benign patients (p < 0.0001), and declined after resection (p < 0.01). High expression of Linc01836 was associated with histological stage (p = 0.002) and lymph node metastasis (p = 0.006). In addition, serum Linc01836 could effectively differentiate CRC patients from the healthy folks, with favorable area under the curve (AUC) of 0.809 (95% CI: 0.757–0.861, p < 0.001). What is more, the combination of serum Linc01836, CEA, and Cyfra21-1 could improve diagnostic sensitivity (92.0%). Linc01836 was averagely located in the nucleus and cytoplasm, suggesting that it might participate in CRC progression and prognosis through the crosstalk among lncRNAs, miRNAs, and mRNAs.

Conclusion: Linc01836 may serve as a valuable noninvasive biomarker for population screening, early detection, and clinical surveillance of CRC.

Review of LINC00707: A Novel LncRNA and Promising Biomarker for Human Diseases

Long noncoding RNAs (lncRNAs) are a major type of noncoding RNA greater than 200 nucleotides in length involved in important regulatory processes. Abnormal expression of certain lncRNAs contributes to the pathogenesis of multiple diseases, including cancers. The lncRNA LINC00707 is located on chromosome 10p14 and is abnormally expressed in numerous disease types, and particularly in several types of cancer. High LINC00707 levels mediate a series of biological functions, including cell proliferation, apoptosis, metastasis, invasion, cell cycle arrest, inflammation, and even osteogenic differentiation. In this review, we discuss the main functions and underlying mechanisms of LINC00707 in different diseases and describe promising applications of LINC00707 in clinical settings.

Silencing of LINC00707 suppresses cell proliferation, migration, and invasion of osteosarcoma cells by modulating miR-338-3p/AHSA1 axis

Osteosarcoma is the most common type of primary malignant tumor of the bone, with a high metastatic rate and poor prognosis. Therefore, it is important to further elucidate the molecular mechanisms involved in the development of osteosarcoma and explore new molecular therapeutic targets. Long intergenic nonprotein-coding RNA 707 (LINC00707) is an oncogenic gene in several cancers. In this study, we further clarified its role and regulatory mechanism in osteosarcoma. We found that LINC00707 levels are significantly higher in the osteosarcoma cell lines SW 1353, HOS, U-2 OS, MG-63, and Saos-2 compared to those in human fetal osteoblastic cell line hFOB1.19. LINC00707 silencing suppressed cell proliferation, migration, and invasion of MG-63 and Saos-2 cells. Moreover, LINC00707 can act as a competitive endogenous RNA of miR-338-3p, and miR-338-3p inhibitor and AHSA1 overexpression alleviated the effect of LINC00707 silencing. In conclusion, we demonstrated high expression of LINC00707 in osteosarcoma cell lines and that silencing LINC00707 suppresses cell proliferation, migration, and invasion by targeting the miR-338-3p/AHSA1 axis in MG-63 and Saos-2 cells. These findings suggest that LINC00707 may serve as a potential target for osteosarcoma treatment.

Formin-like protein 2 promotes cell proliferation by a p27-related mechanism in human breast cancer cells

Background

Breast cancer is the leading cause of cancer-related deaths in females worldwide. Formin-like protein 2 (FMNL2) is a member of formin family that governs cytokinesis, cell polarity, morphogenesis and cell division. To our knowledge, the function of FMNL2 in breast cancer proliferation still remains uncovered.

Methods

Tumor immune estimation resource (TIMER) analysis was used to detect the correlation between FMNL2 and Ki67 in breast cancer tissues. Quantitative real-time transcription polymerase chain reaction (qRT-PCR) and western blotting were performed to analyze the expression in human breast cancer cells. Moreover, RNA interference (RNAi) and plasmids were performed to silence and overexpress FMNL2 and p27. The CCK8, MTT, cell counting, colony formation, and 5-ethynyl-2-deoxyuridine (EdU) incorporation assays were used to detect cell proliferation, respectively. Flow cytometry analysis was used to detect cell cycle distribution. Further, the distribution of p27 was examined using immunofluorescence.

Results

We found that FMNL2 expression was positively associated with Ki67 among collected breast cancer tissues and in TCGA database. Compared to lower proliferative cells MCF7 and T47D, FMNL2 was overexpressed in highly proliferative breast cancer cells MDA-MB-231, BT549 and SUM159, accompanied by reduced levels of p27 and p21, and elevated CyclinD1 and Ki67 expression. FMNL2 silencing significantly inhibited the cell proliferation of MDA-MB-231 and BT549 cells. Meanwhile, FMNL2 overexpression distinctly promoted the cell proliferation of MCF7 cells. Furthermore, FMNL2 suppressed the nuclear levels of p27 and promoted p27 proteasomal degradation in human breast cancer cells. The ubiquitination of p27 was inhibited by FMNL2 silencing in BT549 cells. Besides, p27 silencing markedly elevated Ki67 expression and cell viability, which could be blocked by additionally FMNL2 silencing in MDA-MB-231 and BT549 cells. Furthermore, overexpression of p27WT significantly reversed the increased levels of FMNL2 and Ki67, cell viability and cell cycle progression induced by FMNL2 overexpression in MCF7 cells. More importantly, compared to p27WT group, those effects could be significantly reversed by p27△NLS overexpression.

Conclusions

These results demonstrated that FMNL2 promoted cell proliferation partially by reducing p27 nuclear localization and p27 protein stability in human breast cancer cells, suggesting the pivotal role of FMNL2 in breast cancer progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08533-w.

MiR-466 Inhibits the Progression of Severe Hepatocellular Carcinoma via Regulating FMNL2-Mediated Activation of NF-κB and Wnt/β-Catenin Pathways

Hepatocellular carcinoma (HCC) has threatened the health of humans, and some evidence has indicated that miR-466 involves the progressions of some cancers. This study focused on the role of miR-466 in the formation and development of HCC. The expression levels of miR-466 in the tissues of patients and HCC cell lines were measured by qRT-PCR, and CCK-8, transwell assay, and flow cytometry assay were used to observe the functions of miR-466 on the HCC cells. Moreover, the miRNA databases, dual-luciferase reporter assay, and Western blot were used for the investigation of the regulation mechanism of miR-466 on HCC cells. The results showed that miR-466 was significantly downregulated in HCC tissues and cell lines, and inhibited proliferation, invasion, and high apoptosis were found in HCC cells when miR-466 was overexpressed. The results confirmed that FMNL2 was a target of miR-466, and increased FMNL2 could reverse the effects of miR-466 on the phenotype of HCC cells. Besides, it was also found that miR-466 was involved in the regulation of NF-κB and Wnt/β-catenin pathways in HCC cells via targeting FMNL2. In conclusion, the results of this study suggest that miR-466 regulates the activities of NF-κB and Wnt/β-catenin pathways to inhibit the progression of HCC cells via targeting FMNL2.

miRNA Clusters with Down-Regulated Expression in Human Colorectal Cancer and Their Regulation

Regulation of microRNA (miRNA) expression has been extensively studied with respect to colorectal cancer (CRC), since CRC is one of the leading causes of cancer mortality worldwide. Transcriptional control of miRNAs creating clusters can be, to some extent, estimated from cluster position on a chromosome. Levels of miRNAs are also controlled by miRNAs “sponging” by long non-coding RNAs (ncRNAs). Both types of miRNA regulation strongly influence their function. We focused on clusters of miRNAs found to be down-regulated in CRC, containing miR-1, let-7, miR-15, miR-16, miR-99, miR-100, miR-125, miR-133, miR-143, miR-145, miR-192, miR-194, miR-195, miR-206, miR-215, miR-302, miR-367 and miR-497 and analysed their genome position, regulation and functions. Only evidence provided with the use of CRC in vivo and/or in vitro models was taken into consideration. Comprehensive research revealed that down-regulated miRNA clusters in CRC are mostly located in a gene intron and, in a majority of cases, miRNA clusters possess cluster-specific transcriptional regulation. For all selected clusters, regulation mediated by long ncRNA was experimentally demonstrated in CRC, at least in one cluster member. Oncostatic functions were predominantly linked with the reviewed miRNAs, and their high expression was usually associated with better survival. These findings implicate the potential of down-regulated clusters in CRC to become promising multi-targets for therapeutic manipulation.

Acetyl-11-keto-β-boswellic Acid Inhibits Precancerous Breast Lesion MCF-10AT Cells via Regulation of LINC00707/miR-206 that Reduces Estrogen Receptor-α

Purpose

Acetyl-11-keto-β-boswellic acid (AKBA) has therapeutic effects on a range of diseases, including tumours. lncRNAs, as competing endogenous RNAs (ceRNAs), can interact with miRNAs to regulate the expression of target genes, which can affect the development of tumors. Here, we examined the effects of AKBA on breast precancerous lesions MCF-10AT cells.

Methods

The expression profiles of breast cancer (BC) tissue were collated from The Cancer Genome Atlas (TCGA), and the lncRNA-miRNA-mRNA ceRNA network was constructed. AKBA targets were predicted by network pharmacology. The expression of long intergenic nonprotein-coding RNA 707 (LINC00707), miR-206 and ER-α was determined by qRT-PCR. Cell viability, apoptosis and cycle were assessed by CCK-8 and flow cytometry. Protein levels were measured by Western blotting.

Results

A total of 3205 differentially expressed mRNAs, 104 miRNAs, and 605 lncRNAs were identified. The ceRNA network consisting of 9 lncRNAs, 15 miRNAs and 82 mRNAs was constructed. We found that LINC00707 was up-regulated and miR-206 was down-regulated in MCF-10AT cells. Transfected si-LINC00707 could inhibit cell proliferation, induce cell apoptosis and cycle arrest of MCF-10AT cells. In addition, network pharmacology predicted that AKBA may regulate the ESR1 in the treatment of BC. Our research demonstrated that AKBA could induce cell apoptosis and G1-phase arrest and inhibit ER-α expression via LINC00707/miR-206 in MCF-10AT cells.

Conclusion

AKBA inhibited MCF-10AT cells via regulation of LINC00707/miR-206 that reduces ER-α.

Long non-coding RNA LINC00707 acts as a competing endogenous RNA to enhance cell proliferation in colorectal cancer

Long non-coding RNAs (lncRNAs) have been indicated to serve critical roles in cancer development and progression. Long intergenic non-protein coding RNA 70 (LINC00707) was recently reported to be an oncogene involved in the tumorigenesis of several types of human cancer. However, the clinical role, biological functions and molecular mechanism of LINC00707 in colorectal cancer (CRC) remain unclear. The aim of the present study was to investigate the biological effects and mechanism of LINC00707 in CRC. Reverse transcription-quantitative PCR was used to detect the expression levels of LINC00707 in 65 CRC tissue samples and CRC cell lines (HCT116, HT29 and SW480). Cell Counting Kit-8 and colony formation assays were performed to investigate the effects of LINC00707 on CRC cell proliferation. A dual-luciferase reporter assay was conducted to investigate the mechanisms of LINC00707 in CRC. The upregulation of LINC00707 expression was significantly associated with tumor size, stage and poor survival in patients with CRC. LINC00707 also acted as an independent prognostic factor for CRC. Functional analyses revealed that the knockdown of LINC00707 could inhibit CRC cell proliferation. Furthermore, bioinformatics analysis demonstrated that microRNA (miR)-485-5p could directly bind to LINC00707, which was confirmed by a dual-luciferase reporter assay. In conclusion, the upregulation of LINC00707 is associated with a shorter survival time in patients with CRC. Knockdown of LINC00707 may inhibit the proliferation of CRC cells by binding with miR-485-5p.