Long non-coding RNA LINC00858 promotes cells proliferation, migration and invasion by acting as a ceRNA of miR-22-3p in colorectal cancer

Autophagy-related lncRNAs and exosomal lncRNAs in colorectal cancer: focusing on lncRNA-targeted strategies

Autophagy is a cellular process that involves the degradation and recycling of cellular components, including damaged proteins and organelles. It is an important mechanism for maintaining cellular homeostasis and has been implicated in various diseases, including cancer. Long non-coding RNAs (lncRNAs) are a class of RNA molecules that do not code for proteins but instead play regulatory roles in gene expression. Emerging evidence suggests that lncRNAs can influence autophagy and contribute to the development and progression of colorectal cancer (CRC). Several lncRNAs have been identified as key players in modulating autophagy in CRC. The dysregulation of autophagy and non-coding RNAs (ncRNAs) in CRC suggests a complex interplay between these two factors in the pathogenesis of the disease. Modulating autophagy may sensitize cancer cells to existing therapies or improve the efficacy of new treatment approaches. Additionally, targeting specific lncRNAs involved in autophagy regulation could potentially be used as a therapeutic intervention to inhibit tumor growth, metastasis, and overcome drug resistance in CRC. In this review, a thorough overview is presented, encompassing the functions and underlying mechanisms of autophagy-related lncRNAs in a range of critical areas within tumor biology. These include cell proliferation, apoptosis, migration, invasion, drug resistance, angiogenesis, and radiation resistance.

LINC00858 facilitates the malignant development of Wilms' Tumor by targeting miR-653-5p

BACKGROUND

To uncover the clinical significance of LINC00858 in the development of Wilms' Tumor and the potential molecular mechanism.

METHODS

LINC00858 levels in Wilms' Tumor species and cell lines were determined by quantitative real-time polymerase chain reaction (qRT-PCR). The clinical significance of LINC00858 in influencing pathological features and prognosis in patients with Wilms' Tumor was analyzed. Proliferative and migratory changes in Wilms' Tumor cells with LINC00858 knockdown were assessed. The downstream gene of LINC00858 was verified by luciferase assay, and its involvement in the development of Wilms' Tumor was further explored.

RESULTS

LINC00858 was highly expressed in Wilms' Tumor tissues and cell lines. High level of LINC00858 was correlated to high rate of lymphatic metastasis and poor prognosis in patients with Wilms' Tumor. Knockdown of LINC00858 suppressed proliferative and migratory potentials in HFWT and 17-94 cells. MiR-653-5p was targeted by LINC00858. It was lowly expressed in Wilms' Tumor tissues and negatively regulated by LINC00858. Knockdown of miR-653-5p partially abolished the regulatory effects of LINC00858 on proliferative and migratory potentials in Wilms' Tumor cells.

CONCLUSIONS

LINC00858 is highly expressed in Wilms' Tumor species and correlated to lymphatic metastasis rate and overall survival in patients with Wilms' Tumor. Knockdown of LINC00858 suppresses Wilms' Tumor cells to proliferate and migrate via targeting miR-653-3p.

Competitive endogenous RNA networks: Decoding the role of long non-coding RNAs and circular RNAs in colorectal cancer chemoresistance

Colorectal cancer (CRC) is recognized as one of the most common gastrointestinal malignancies across the globe. Despite significant progress in designing novel treatments for CRC, there is a pressing need for more effective therapeutic approaches. Unfortunately, many patients undergoing chemotherapy develop drug resistance, posing a significant challenge for cancer treatment. Non-coding RNAs (ncRNAs) have been found to play crucial roles in CRC development and its response to chemotherapy. However, there are still gaps in our understanding of interactions among various ncRNAs, such as long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs). These ncRNAs can act as either oncogenes or tumour suppressors, affecting numerous biological functions in different cancers including CRC. A class of ncRNA molecules known as competitive endogenous RNAs (ceRNAs) has emerged as a key player in various cellular processes. These molecules form networks through lncRNA/miRNA/mRNA and circRNA/miRNA/mRNA interactions. In CRC, dysregulation of ceRNA networks has been observed across various cellular processes, including proliferation, apoptosis and angiogenesis. These dysregulations are believed to play a significant role in the progression of CRC and, in certain instances, may contribute to the development of chemoresistance. Enriching our knowledge of these dysregulations holds promise for advancing the field of diagnostic and therapeutic modalities for CRC. In this review, we discuss lncRNA- and circRNA-associated ceRNA networks implicated in the emergence and advancement of drug resistance in colorectal carcinogenesis.

Long noncoding RNA LINC00858 aggravates the progression of esophageal squamous cell carcinoma via regulating the miR-425-5p/ABL2 axis

Esophageal squamous cell carcinoma (ESCC) is one of the most fatal cancers with high morbidity and mortality, which severely affects people's lives. Long intergenic non-protein coding RNA 858 (LINC00858) was confirmed to promote the progression of colorectal cancer and lung cancer. However, the role of lncRNA LINC00858 is still unknown in ESCC. Herein, the main purpose of research was to explore LINC00858 function and its impact on ESCC cell biological behaviors. RT-qPCR was used to test the expression of LINC00858, miR-425-5p and ABL proto-oncogene 2 (ABL2) in ESCC cells. Functional experiments such as EdU assay, CCK-8 assay, transwell assay and Western blot assay were conducted to investigate the biological behaviors of ESCC cells. Luciferase reporter assay and RIP assay were implemented to determine the binding situation among RNAs. LINC00858 expression was abnormally high in ESCC cells and down-regulation of LINC00858 could restrain the proliferation, invasion, migration and EMT process of ESCC cells. Furthermore, miR-425-5p was proved to be sponged by LINC00858 and was down-regulated in ESCC cells. Besides, we discovered that miR-425-5p could target ABL2. Moreover, knockdown of ABL2 reversed the promoting function of miR-425-5p inhibitor on ESCC progression. LINC00858 aggravated ESCC progression via regulating the miR-425-5p/ABL2 axis.

Somatic Copy Number Alterations in Colorectal Cancer Lead to a Differentially Expressed ceRNA Network (ceRNet)

Colorectal cancer (CRC) represents the second deadliest malignancy worldwide. Around 75% of CRC patients exhibit high levels of chromosome instability that result in the accumulation of somatic copy number alterations. These alterations are associated with the amplification of oncogenes and deletion of tumor-ppressor genes and contribute to the tumoral phenotype in different malignancies. Even though this relationship is well known, much remains to be investigated regarding the effect of said alterations in long non-coding RNAs (lncRNAs) and, in turn, the impact these alterations have on the tumor phenotype. The present study aimed to evaluate the role of differentially expressed lncRNAs coded in regions with copy number alterations in colorectal cancer patient samples. We downloaded RNA-seq files of the Colorectal Adenocarcinoma Project from the The Cancer Genome Atlas (TCGA) repository (285 sequenced tumor tissues and 41 non-tumor tissues), evaluated differential expression, and mapped them over genome sequencing data with regions presenting copy number alterations. We obtained 78 differentially expressed (LFC > 1|< -1, padj < 0.05) lncRNAs, 410 miRNAs, and 5028 mRNAs and constructed a competing endogenous RNA (ceRNA) network, predicting significant lncRNA-miRNA-mRNA interactions. Said network consisted of 30 lncRNAs, 19 miRNAs, and 77 mRNAs. To understand the role that our ceRNA network played, we performed KEGG and GO analysis and found several oncogenic and anti-oncogenic processes enriched by the molecular players in our network. Finally, to evaluate the clinical relevance of the lncRNA expression, we performed survival analysis and found that C5orf64, HOTAIR, and RRN3P3 correlated with overall patient survival. Our results showed that lncRNAs coded in regions affected by SCNAs form a complex gene regulatory network in CCR.

Prognostic Biomarkers of Cell Proliferation in Colorectal Cancer (CRC): From Immunohistochemistry to Molecular Biology Techniques

Colorectal cancer (CRC) is one of the most common and severe malignancies worldwide. Recent advances in diagnostic methods allow for more accurate identification and detection of several molecular biomarkers associated with this cancer. Nonetheless, non-invasive and effective prognostic and predictive testing in CRC patients remains challenging. Classical prognostic genetic markers comprise mutations in several genes (e.g., APC, KRAS/BRAF, TGF-β, and TP53). Furthermore, CIN and MSI serve as chromosomal markers, while epigenetic markers include CIMP and many other candidates such as SERP, p14, p16, LINE-1, and RASSF1A. The number of proliferation-related long non-coding RNAs (e.g., SNHG1, SNHG6, MALAT-1, CRNDE) and microRNAs (e.g., miR-20a, miR-21, miR-143, miR-145, miR-181a/b) that could serve as potential CRC markers has also steadily increased in recent years. Among the immunohistochemical (IHC) proliferative markers, the prognostic value regarding the patients' overall survival (OS) or disease-free survival (DFS) has been confirmed for thymidylate synthase (TS), cyclin B1, cyclin D1, proliferating cell nuclear antigen (PCNA), and Ki-67. In most cases, the overexpression of these markers in tissues was related to worse OS and DFS. However, slowly proliferating cells should also be considered in CRC therapy (especially radiotherapy) as they could represent a reservoir from which cells are recruited to replenish the rapidly proliferating population in response to cell-damaging factors. Considering the above, the aim of this article is to review the most common proliferative markers assessed using various methods including IHC and selected molecular biology techniques (e.g., qRT-PCR, in situ hybridization, RNA/DNA sequencing, next-generation sequencing) as prognostic and predictive markers in CRC.

Long intergenic non-protein coding RNA 00858 participates in the occurrence and development of esophageal squamous cell carcinoma through the activation of the FTO-m6A-MYC axis by recruiting ZNF184

OBJECTIVES

We aimed at probing impact of LINC00858 on esophageal squamous cell carcinoma (ESCC) progression via ZNF184-FTO-m⁶A-MYC axis.

METHODS

Expression of related genes (LINC00858, ZNF184, FTO, and MYC) was detected in ESCC tissues or cells and their relationships were assessed. After expression alterations in ESCC cells, cell proliferation, invasion, migration, and apoptosis were detected. Tumor formation in nude mice was conducted.

RESULTS

LINC00858, ZNF184, FTO, and MYC were overexpressed in ESCC tissues and cells. LINC00858 enhanced ZNF184 expression to upregulate FTO, which augmented MYC expression. LINC00858 knockdown diminished ESCC cell proliferative, migratory, and invasive properties while elevating apoptosis, which was negated by FTO overexpression. FTO knockdown exerted similar functions of LINC00858 knockdown on ESCC cell movements, which was annulled by MYC upregulation. Silencing LINC00858 repressed tumor growth and related gene expression in nude mice.

CONCLUSIONS

LINC00858 modulated MYC m⁶A modification via FTO by recruiting ZNF184, thus facilitating ESCC progression.

lncRNA TRPM2-AS Promotes Colorectal Cancer Progression by Regulating miR-22-3p and FSTL1

Background. In recent years, long noncoding RNAs (lncRNAs) relate to many biological processes, which affect the progression of tumors. Transient receptor potential melastatin 2 antisense RNA (TRPM2-AS) is reported to play an oncogene-like role in tumors. TRPM2-AS is highly expressed in colorectal cancer (CRC), but the mechanism of TRPM2-AS is still unclear. The regulatory mechanism of TRPM2-AS in the occurrence of CRC was explored, so as to find new markers and therapeutic targets for CRC. Methods. TRPM2-AS and miR-22-3p expression in CRC cells were measured through reverse-transcription quantitative polymerase chain reaction (RT-qPCR). Then, TRPM2-AS knockdown cell lines were constructed, and cell counting kit-8 (CCK-8), clone formation, wound healing, and invasion assays were used to detect cell malignant behavior. Follistatin-like 1 (FSTL1) protein was detected by western blotting. The interaction between miR-22-3p and TRPM2-AS or FSTL1 was verified by the luciferase reporter and RNA immunoprecipitation (RIP) assay. Subcutaneous xenografts were performed using animal experiments. Results. TRPM2-AS expression in CRC cells was increased, and miR-22-3p expression was decreased in CRC cells. TRPM2-AS inhibition inhibited cell malignant behavior. miR-22-3p has a targeting relationship with TRPM2-AS and FSTL1. In cells, downregulation of TRPM2-AS expression promoted miR-22-3p and inhibited FSTL1 expression, while mimics inhibited FSTL1 expression. miR-22-3p inhibition or FSTL1 overexpression could offset the inhibition of TRPM2-AS downregulation on CRC cells. Conclusions. The TRPM2-AS/miR-22-3p/FSTL1 regulation axis could regulate CRC cell malignant behavior, which may provide a new perspective for interpreting the mechanism of CRC development.

Retracted: Up-regulated Linc00472 suppresses development of lung cancer cell via inhibition of MiR-196b-5p

The role of linc00472 in lung cancer (LC) has been rarely reported. We aimed to study the role of linc00472 in LC progression. Expressions of linc00472 and miR-196b-5p in LC cell lines were measured by qRT-PCR. The targeting relationship between linc00472 and miR-196b-5p was determined by Starbase and dual-luciferase reporter. The viability, migration, invasion, and apoptosis of LC cells were determined using CCK-8 assay, scratch test, transwell assay, and flow cytometry, respectively. The levels of epithelial-to-mesenchymal transition (EMT)-related proteins and apoptosis-related proteins in LC cells were determined by western blot. Down-regulated linc00472 was observed in five LC cell lines. Linc00472 overexpression suppressed viability, migration, invasion and EMT process, but elevated apoptotic rate in LC cells. MiR-196b-5p mimic promoted viability, migration, invasion, and EMT process, but decreased apoptotic rate, which was reversed by up-regulated linc00472. Linc00472 functioned as a cancer suppressor via negatively regulating miR-196b-5p of LC cells.

miR-22 Suppresses EMT by Mediating Metabolic Reprogramming in Colorectal Cancer through Targeting MYC-Associated Factor X

Colorectal cancer (CRC) is one of the most frequent gastrointestinal cancers. MicroRNAs (miRNAs) have been proved to be unusually expressed in CRC progression and thus alter multiple pathological processes in CRC cells. However, the specific roles and mechanisms of miR-22 in CRC have not been clearly reported. MicroRNA-22 (miR-22) and MYC-associated factor X (MAX) expressions were determined by RT-qPCR in CRC tissues and cells. The targeted regulatory effects of miR-22 and MAX were confirmed by luciferase reporter and coimmunoprecipitation assays. Also, gain- and loss-of-function and rescue experiments were used to elucidate the function and mechanism of miR-22 and MAX in CRC cells and the mouse xenograft model. We discovered that miR-22 was hypermethylated and downregulated, while MAX was upregulated in CRC. miR-22 markedly inhibited migration, invasion, glycolysis, and cancer stem cell transcription factors in CRC cells. In addition, it was found that miR-22 can directly target MAX. Additional functional experiments confirmed that MAX overexpression can rescue the effects of miR-22 on the behavior of CRC cells. This study suggested that miR-22, as a cancer suppressor, participates in CRC progression by targeting MAX, which might provide basic information for therapeutic targets for CRC.

Regulatory Roles of Noncoding RNAs in the Progression of Gastrointestinal Cancers and Health Disparities

Annually, more than a million individuals are diagnosed with gastrointestinal (GI) cancers worldwide. With the advancements in radio- and chemotherapy and surgery, the survival rates for GI cancer patients have improved in recent years. However, the prognosis for advanced-stage GI cancers remains poor. Site-specific GI cancers share a few common risk factors; however, they are largely distinct in their etiologies and descriptive epidemiologic profiles. A large number of mutations or copy number changes associated with carcinogenesis are commonly found in noncoding DNA regions, which transcribe several noncoding RNAs (ncRNAs) that are implicated to regulate cancer initiation, metastasis, and drug resistance. In this review, we summarize the regulatory functions of ncRNAs in GI cancer development, progression, chemoresistance, and health disparities. We also highlight the potential roles of ncRNAs as therapeutic targets and biomarkers, mainly focusing on their ethnicity-/race-specific prognostic value, and discuss the prospects of genome-wide association studies (GWAS) to investigate the contribution of ncRNAs in GI tumorigenesis.

The therapeutic effect of exosomes from mesenchymal stem cells on colorectal cancer: Toward cell-free therapy

Colorectal cancer (CRC) is known for its high mortality rate and affects more men than women. The treatment requires invasive surgical interventions, however, the progression of CRC metastasis is difficult to control in most cases. Mesenchymal stem cells (MSCs) with their outstanding characteristics have been widely used in the treatment of degenerative diseases as well as cancers. They affect the tumor microenvironment through either cell-cell interactions or communications with their secretome. While stem cells may represent a dual role in tumor proliferation and progression, exosomes have attracted much attention as a cell-free therapy in CRC treatment. Exosomes derived from native or genetically modified MSCs, as well as exosomal microRNAs (miRNAs), have been evaluated on CRC progression. Moreover, MSC-derived exosomes have been used as a carrier to deliver anticancer agents in colorectal cancer. In this review, we overview and discuss the current knowledge in both stem cell-based and cell-free exosome therapy of CRC.

TP73-AS1 as a predictor of clinicopathological parameters and prognosis in human malignancies: a meta and bioinformatics analysis

Background

Long non-coding RNA P73 antisense RNA 1 T (non-protein coding), also known as Lnc RNA TP73-AS1, is dysregulated in various tumors but the correlation between its expression and clinicopathological parameters and/or prognoses in cancer patients is inconclusive. Here, we performed a meta-analysis to evaluate the prognostic value of Lnc RNA TP73-AS1 for malignancies.

Methods

We systematically searched four online databases including PubMed, the Web of Science, Embase, and the Cochrane Library for eligible articles published up to June 29/2020. Odds ratios (ORs) and Pooled hazard ratios (HRs) with 95% confidence intervals (95% CIs) were used to assess the association of TP73-AS1 expression with prognostic and clinicopathological parameters. We further validated TP73-AS1 expression in various malignancies and its potential prognostic value using the GEPIA online database. We predicted potential biological processes and relevant signal mechanisms through the public databases.

Results

A total of 26 studies examining 14 cancers were analyzed to evaluate the relationship between TP73-AS1 expression, clinicopathological features and prognostic indicators. The results indicated that TP73-AS1 expression markedly correlates with TNM stage (OR = 3.27,95% CI:2.43–4.39, P < 0.00001), tumor size (OR = 3.00, 95%CI:2.08–4.35, P < 0.00001), lymph node metastasis (OR = 2.77, 95%CI:1.42–5.38,P < 0.00001) and distant metastasis (OR = 4.50,95%CI:2.

62–7.73,P < 0.00001). No correlation with age (OR = 1.12,95%CI:0.77–1.64, P > 0.05), gender (OR = 1.08, 95%CI:0.84–1.38, P > 0.05) or differentiation (OR = 1.39, 95%CI:0.71–2.70, P = 0.340) was observed. TP73-AS1 overexpression was a biomarker of poor Overall survival(OS)(HR = 1.85,95%CI:1.53–2.22, P < 0.00001) and Disease-Free-Survival (DFS) (HR = 1.57,95%CI:1.03–2.42, P < 0.05). Dysregulated TP73-AS1 expression and its prognostic value in various cancers was validated based on The Cancer Genome Atlas (TCGA). Further biological function predictions indicated that TP73-AS1 was involved in pro-oncogenic signaling.

Conclusions

The upregulation of Lnc RNA TP73-AS1 was related to detrimental clinicopathological parameters and can be considered an indicator of poor prognosis for cancer malignancies.

FAM49B, restrained by miR-22, relieved hepatic ischemia/reperfusion injury by inhibiting TRAF6/IKK signaling pathway in a Rac1-dependent manner

Hepatic ischemia/reperfusion (I/R) injury plays a pivotal pathogenic role in trauma, hepatectomy, and liver transplantation. However, the whole mechanism remains undescribed. The objective of this study is to investigate the internal mechanism by which microRNA-22 (miR-22) targets family with sequence similarity 49 member B (FAM49B), thus aggravating hepatic I/R injury. Here, we found that miR-22 was upregulated while FAM49B was reduced in hepatic I/R injury. Inhibition of miR-22 in vitro was able to intensify expression of FAM49B, thus reducing phosphorylation of inhibitors of nuclear factor kappa-B kinase (IKK) and downstream pro-inflammatory proteins. A dual luciferase reporter assay indicated that miR-22 directly targeted FAM49B. Remission of hepatic pathologic alterations, apoptosis, and release of cytokines derived from constraints of miR-22 were abolished in vivo by repressing FAM49B. Further interference of Ras-related C3 botulinum toxin substrate 1 (Rac1) reversed the function of FAM49B inhibition, thus achieving anti-inflammatory consequences.

Circ-ACAP2 facilitates the progression of colorectal cancer through mediating miR-143-3p/FZD4 axis

BACKGROUND

Circular RNAs (circRNAs) play crucial roles in multiple cancers, including colorectal cancer (CRC). Here, we explored the role of circRNA ArfGAP with coiled-coil, ankyrin repeat and PH domains 2 (circ-ACAP2) in the progression and radioresistance of CRC.

METHODS

Quantitative real-time polymerase chain reaction (qPCR) and Western blot assay were used to detect RNA and protein expression, respectively. The proliferation, apoptosis, migration, invasion and radioresistance of CRC cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, transwell migration assay, transwell invasion assay and colony formation assay. The target interaction between microRNA-143-3p (miR-143-3p) and circ-ACAP2 or frizzled class receptor 4 (FZD4) was verified by dual-luciferase reporter assay. Murine xenograft model was established to explore the role of circ-ACAP2 in vivo.

RESULTS

The expression of circ-ACAP2 was prominently enhanced in CRC tissues and cell lines. Circ-ACAP2 facilitated the proliferation, migration, invasion and radioresistance whereas inhibited the apoptosis of CRC cells. MiR-143-3p was a direct target of circ-ACAP2 in CRC cells. Circ-ACAP2 promoted the progression and radioresistance of CRC partly by sponging miR-143-3p. MiR-143-3p interacted with the 3' untranslated region (3'UTR) of FZD4 in CRC cells, and FZD4 overexpression partly reversed miR-143-3p-mediated effects in CRC cells. Wnt/β-catenin signalling was modulated by circ-ACAP2/miR-143-3p/FZD4 axis in CRC cells.

CONCLUSION

Circ-ACAP2 contributed to the development and radioresistance of CRC partly through targeting miR-143-3p/FZD4 axis, which provided novel potential diagnostic and therapeutic targets for CRC.

LncRNA FGD5-AS1 functions as an oncogene to upregulate GTPBP4 expression by sponging miR-873-5p in hepatocellular carcinoma

The long non-coding FGD5-AS1 (LncFGD5-AS1) has been reported to be a novel carcinogenic gene and participant in regulating tumor progression by sponging microRNAs (miRNAs). However, the pattern of expression and the biological role of FGD5-AS1 in hepatocellular carcinoma (HCC) remains largely unknown. The expression level of FGD5-AS1 in tumor tissues and cell lines was measured by RT-qPCR. CCK-8, EdU, flow cytometry, wound healing and transwell chamber assays were performed to investigate the role of FGD5-AS1 in cell proliferation, apoptosis, migration, and invasion in HCC. Dual luciferase reporter, and RNA pull-down assays were performed to identify the regulatory interactions among FGD5-AS1, miR-873-5p and GTP-binding protein 4 (GTPBP4). We found that the expression of FGD5-AS1 was upregulated in HCC tissues and cell lines. Moreover, the knockdown of FGD5-AS1 suppressed cell proliferation, migration and invasion, and induced apoptosis in HCC cells. Further studies demonstrated that FGD5-AS1 could function as a competitive RNA by sponging miR-873-5p in HCC cells. Moreover, GTPBP4 was identified as direct downstream target of miR-873-5p in HCC cells and FGD5-AS1mediated the effects of GTPBP4 by competitively binding with miR-873-5p. Taken together, this study demonstrated the regulatory role of FGD5-AS1 in the progression of HCC and identified the miR-873-5p/GTPBP4 axis as the direct downstream pathway. It represents a promising novel therapeutic strategy for HCC patients.

Risk Scores Based on Six Survival-Related RNAs in a Competing Endogenous Network Composed of Differentially Expressed RNAs Between Clear Cell Renal Cell Carcinoma Patients Carrying Wild-Type or Mutant Von Hippel-Lindau Serve Well to Predict Malignancy and Prognosis

Clear cell renal cell carcinoma (ccRCC) carrying wild-type Von Hippel–Lindau (VHL) tumor suppressor are more invasive and of high morbidity. Concurrently, competing endogenous RNA (ceRNA) network has been suggested to play an important role in ccRCC malignancy. In order to understand why the patients carrying wild-type VHL gene have high degrees of invasion and morbidity, we applied bioinformatics approaches to identify 861 differentially expressed RNAs (DE-RNAs) between patients carrying wild-type and patients carrying mutant VHL from The Cancer Genome Atlas (TCGA) database, established a ceRNA network including 122 RNAs, and elected six survival-related DE-RNAs including Linc00942, Linc00858, RP13_392I16.1, hsa-miR-182-5p, hsa-miR-183-5p, and PAX3. Examining clinical samples from our hospital revealed that patients carrying wild-type VHL had significantly higher levels of all six RNAs than those carrying mutant VHL. Patients carrying wild-type VHL had significantly higher risk scores, which were calculated based on expression levels of all six RNAs, than those carrying mutant VHL. Patients with higher risk scores had significantly shorter survival times than those with lower risk scores. Therefore, the risk scores serve well to predict malignancy and prognosis.

MicroRNA-22-3p targeted regulating transcription factor 7-like 2 (TCF7L2) constrains the Wnt/β-catenin pathway and malignant behavior in osteosarcoma

Various studies have manifested that microRNAs (miRNAs) are involved in the modulation of the occurrence and development of osteosarcoma (OS). However, whether miR-22-3p is associated with OS growth remains unclear. In the study, the potential molecular mechanisms of miR-22-3p in OS was explored. It was affirmed that miR-22-3p was associated with distant metastasis and tumor size in OS patients, and reduced in OS tissues and cells while transcription factor 7-like 2 (TCF7L2) was elevated. Elevated miR-22-3p repressed OS cell progression, and the Wnt/β-catenin pathway, while elevated TCF7L2 was opposite. MiR-22-3p targeted TCF7L2 in OS. In functional rescue experiments, knockdown of miR-22-3p on OS progression and promotion of Wnt/β-catenin were reversed by simultaneous knockdown of TCF7L2. Transplantation experiments in nude mice showed that elevated miR-22-3p repressed OS tumor growth and decreased TCF7L2, Wnt and β-catenin. Shortly, this study suggest that miR-22-3p refrains the Wnt/β-catenin pathway by targeting TCF7L2 and thereby preventing OS deterioration. MiR-22-3p/TCF7L2 axis is supposed to be a candidate molecular target for future OS treatment.

The tumorigenic function of LINC00858 in cancer

Long non-coding RNA (lncRNA) plays an important regulatory role in the occurrence and development of human cancer. LINC00858 is a newly discovered lncRNA with a length of 2685 nucleotides. Existing studies have shown that LINC00858 has abnormally high expression levels in malignant tumors such as colorectal cancer, gastric cancer, hepatocellular carcinoma, lung cancer, non-small cell lung cancer, ovarian cancer, osteosarcoma, retinoblastoma, Wilms tumor, bladder cancer, and cervical cancer. By regulating a variety of microRNAs, LINC00858 can affect tumor cell proliferation, invasion, metastasis, and apoptosis. Related research also found that LINC00858 is related to nuclear transcription factor/protein kinase and gene methylation. The aberrant expression of LINC00858 is related to the prognosis and clinicopathological characteristics of a variety of tumors. Overexpressed LINC00858 is closely related to the clinical stage, lymph node metastasis, and distant metastasis of cancer, including colorectal cancer, gastric cancer, non-small cell lung cancer, ovarian cancer, and Wilms tumor. Also, it is summarized that LINC00858 can regulate MAPK and TGF-β signaling pathways. This review shows that LINC00858 as an important oncogene can promote tumorigenesis and cancer development.

LncRNA MCF2L-AS1 aggravates the malignant development of colorectal cancer via targeting miR-105-5p/RAB22A axis

BACKGROUND

Colorectal cancer (CRC) represents one of the major malignant cancers in the world. It has been demonstrated that long non-coding RNAs (lncRNAs) can cause great influences on various human cancers. Though MCF.2 cell line derived transforming sequence like antisense RNA 1 (MCF2L-AS1) and its carcinogenic effect in CRC has been elucidated by several previous researches, the underlying mechanism remains unknown.

AIM

We aimed at exploring the function and regulatory mechanism of MCF2L-AS1 in CRC.

METHODS

MCF2L-AS1 expression in CRC cells was tested via RT-qPCR assay. The effects of MCF2L-AS1 on the biological properties of CRC cells were testified through functional experiments. The molecular mechanism of MCF2L-AS1 was verified through mechanism experiments.

RESULTS

MCF2L-AS1 was highly expressed in CRC cells, and it could enhance the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) process of CRC cells. MiR-105-5p was sponged by MCF2L-AS1 in CRC cells and Ras-related protein Rab-22A (RAB22A) was verified to be the downstream target of miR-105-5p. It was verified through rescue assays that RAB22A overexpression or miR-105-5p silencing could reverse the repressive impact of MCF2L-AS1 silencing on CRC progression.

CONCLUSION

MCF2L-AS1 accelerated the malignant development of CRC cells by targeting the miR-105-5p/RAB22A axis.

Circ_0007534 Silencing Inhibits the Proliferation, Migration and Invasion and Induces the Apoptosis of Glioma Cells Partly Through Down-Regulating PROX1 Via Elevating miR-22-3p Level

Glioma is a common malignant brain neoplasm. The role and mechanism of circular RNA 0,007,534 (circ_0007534) in glioma progression were investigated in this study. The expression of circ_0007534, microRNA-22-3p (miR-22-3p) and prospero homeobox protein 1 (PROX1) messenger RNA (mRNA) was determined by quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation, migration and invasion abilities were analyzed by colony formation assay, transwell migration assay and transwell invasion assay. Cell apoptosis was assessed through measuring the activity of Caspase-3 using the Caspase-3 kit and the apoptosis rate using flow cytometry. Dual-luciferase reporter assay was used to confirm the target interaction between miR-22-3p and circ_0007534 or PROX1. The protein level of PROX1 was examined by Western blot assay. Animal studies were conducted to analyze the influence of circ_0007534 interference on xenograft tumor growth in vivo. Circ_0007534 was highly expressed in glioma tissues and cell lines relative to that in normal tissues and NHA cell line. Circ_0007534 knockdown suppressed the proliferation and motility while induced the apoptosis of glioma cells. Circ_0007534 negatively regulated miR-22-3p level through targeting it in glioma cells. Circ_0007534 interference-induced influences in glioma cells were partly overturned by the silencing of miR-22-3p. PROX1 was a target of miR-22-3p, and circ_0007534 interference-mediated effects in glioma cells were largely diminished by the overexpression of PROX1. Circ_0007534 interference restrained glioma development in vivo. Circ_0007534 aggravated glioma progression through elevating PROX1 expression via targeting miR-22-3p, which provided new targets for the diagnosis and treatment of glioma.

Long non-coding RNA RP11-490M8.1 inhibits lipopolysaccharide-induced pyroptosis of human umbilical vein endothelial cells via the TLR4/NF-κB pathway

BACKGROUND AND AIMS

Pyroptosis is a relatively newly discovered form of programmed cell death that plays an important role in the development of atherosclerosis. Many studies have reported that lncRNAs participated in the regulation of atherosclerosis development. However, the regulatory mechanism of lncRNAs in pyroptosis must be studied further.

METHODS

In a previous study, microarray analysis was used to detect the lncRNA expression profile in three human advanced atherosclerotic plaques and three normal arterial intimae. In the present research, in vitro assays were performed to investigate the role of lncRNA RP11-490M8.1 on pyroptosis. The relative gene mRNA and lncRNA expression levels were tested by quantitative real-time PCR, and protein levels were evaluated by western blot analysis. The RNA hybrid structure was analyzed using the DINAMelt server.

RESULTS

The lncRNA RP11-490M8.1 was significantly downregulated in atherosclerotic plaques and serum. Lipopolysaccharide (LPS) markedly reduced the expression of lncRNA RP11-490M8.1 and induced pyroptosis by increasingthe mRNA and protein levels of NLRP3, caspase-1, ASC, IL-1β, and IL-18 in HUVECs. The promotion effects ofLPS on pyroptosis were markedly suppressed by overexpression of lncRNA RP11-490M8.1. In addition, LPS increased the mRNA and protein levels ofTLR4 and NF-κB, which was also markedly offsetby overexpression of lncRNA RP11-490M8.1.

CONCLUSIONS

These findings indicated that lncRNA RP11-490M8.1 inhibited LPS-induced pyroptosis via the TLR4/NF-κB pathway. Thus, lncRNA RP11-490M8.1 may provide a therapeutic target to ameliorate atherosclerosis.

Long noncoding RNA LINC00858 promotes the progression of ovarian cancer via regulating the miR-134-5p/TRIM44 axis

Recent studies have shown that many long noncoding RNAs (lncRNAs) are abnormally expressed in ovarian cancer and involved in the pathological progress of ovarian cancer. In the present study, we aimed to investigate the role of lncRNA LINC00858 and the potential mechanism in ovarian cancer. The qRT-PCR was used to measure the expression levels of LINC00858 and miR-134-5p in ovarian cancer tissue specimens and cell lines. Loss-of-function assays were performed to investigate the role of LINC00858 in ovarian cancer. MTT assay was carried out to measure cell proliferation. Transwell assays were performed to determine cell migration and invasion. Biological information analysis and luciferase report gene assay were used to verify potential downstream genes of LINC00858. The xenograft mouse model was established to analyze tumor growth in vivo. Our results showed that LINC00858 was highly expressed in human ovarian cancer tissues and cell lines. Knockdown of LINC00858 inhibited cell proliferation, migration and invasion of SKOV3 cells, and suppressed tumor growth in mouse xenograft models. Mechanistic studies revealed that LINC00858 acted as a sponge of miR-134-5p and then regulated TRIM44 expression in SKOV3 cells. Furthermore, rescue experiments illustrated that inhibition of miR-134-5p restored the inhibitory effects of LINC00858 knockdown on cell proliferation, migration and invasion. TRIM44 overexpression could counteract the inhibitory effects of miR-134-5p mimics on ovarian cancer cells. In conclusion, these findings demonstrated that LINC00858 exerted oncogenic role in ovarian cancer, which was mediated by miR-134-5p/TRIM44 axis. Thus, LINC00858 might be a therapeutic target for the treatment of ovarian cancer.

Exosomes miR-22-3p Derived from Mesenchymal Stem Cells Suppress Colorectal Cancer Cell Proliferation and Invasion by Regulating RAP2B and PI3K/AKT Pathway

Objective

Exosomes (exo) which contain proteins, microRNAs (miRNAs), and other bioactive substances can participate in intercellular signal transduction and material transport. Bone marrow mesenchymal stem cells (BMSCs) have a strong ability to produce exosomes. The purpose of this study was to observe the effect of hBMSCs-derived-exo miR-22-3p on proliferation and invasion of colorectal cancer (CRC) cells and to explore its mechanism.

Methods

miR-22-3p and RAS oncogene family (RAP2B) expression was detected using qRT-PCR or Western blotting. Their interaction was confirmed by dual luciferase activity assay. Effects of miR-22-3p on cell proliferation and invasion were evaluated by CCK-8 and Transwell assay, respectively. Exosomes were extracted by the ultracentrifugation and identified through electron microscopy and Western blotting.

Results

In CRC tissues and cells, downregulation of miR-22-3p and upregulation of RAP2B were observed. According to the analysis of dual luciferase activity, RAP2B was a target gene of miR-22-3p. In addition, miR-22-3p obviously repressed the cells proliferation and invasion via mediating RAP2B/PI3K/AKT pathway. Coculture experiments indicated that miR-22-3p derived from hBMSCs-exo had inhibition effects on SW480 cell proliferation and invasion.

Conclusions

Collectively, miR-22-3p from hBMSCs-exo might impede CRC progression, which emphasized the potential of hBMSCs-exo-miR-22-3p as CRC treatment in the future.

Long non‑coding RNA 00858 knockdown alleviates bladder cancer via regulation of the miR‑3064‑5p/CTGF axis

The long non-coding RNA 00858 (LINC00858) has been reported to be an oncogene for various cancer diseases, including osteosarcoma and colorectal cancer. However, the expression pattern and function of LINC00858 in bladder cancer remain largely unknown. The expression level of LINC00858 was measured in tumor tissues and cell lines by RT-qPCR. The role of LINC00858 in bladder cancer cells were studied by gain- and loss-of-function strategies in vitro. Cell proliferation, migration and invasion were assessed by CCK-8, colony formation, wound healing and Transwell chamber assays. At the molecular level, dual luciferase reporter and RNA RIP assays were performed to identify the interaction among LINC00858, microRNA (miR)-3064-5p and cellular communication network factor 2 (CTGF). The results revealed that the expression level of LINC00858 was upregulated in bladder cancer tissues and cell lines including T24, J82 and 5637. Moreover, knockdown of LINC00858 suppressed cell proliferation, migration and invasion in vitro. Mechanistically, LINC00858 functioned as a competitive RNA to increase the expression level of oncogene CTGF by sequestering miR-3064-5p. In conclusion, LINC00858 knockdown inhibited the proliferation, migration and invasion of bladder cancer cells via regulation of the miR-3064-5p/CTGF axis.

SP1-induced lncRNA DANCR contributes to proliferation and invasion of ovarian cancer

Transcription factor SP1 could manipulate pathways involved in ovarian cancer progression. LncRNAs are involved in SP1-mediated tumorigenesis. LncRNA DANCR could promote metastasis of ovarian cancer. However, the regulatory function and involvement of SP1-induced lncRNA DANCR in ovarian cancer remain elusive. Data from this study showed that SP1 was up-regulated in ovarian cancer tissues and cells (CAOV3, SKOV3, A2780), and SP1 could bind to the promoter region of DANCR through chromatin immunoprecipitation and leuciferase activity assays. Therefore, DANCR was transcriptionally induced by SP1 in ovarian cancer tissues and cells (CAOV3, SKOV3, A2780). Functionally, reduced expression of DANCR suppressed cell viability, migration and invasion of CAOV3, while enhanced DANCR expression contributed to SKOV3 growth. Over-expression of SP1 reversed the suppressive effects of DANCR interference on ovarian cancer progression. In conclusion, SP1-induced DANCR contributed to oncogenic potential of ovarian cancer, suggesting a promising therapeutic target for ovarian cancer.

The Emerging Landscape of Long Non-Coding RNAs in Colorectal Cancer Metastasis

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers, with extremely high rates of morbidity and mortality. The main cause of death in CRC is distant metastasis; it affects patient prognosis and survival and is one of the key challenges in the treatment of CRC. Long non-coding RNAs (lncRNAs) are a group of non-coding RNA molecules with more than 200 nucleotides. Abnormal lncRNA expression is closely related to the occurrence and progression of several diseases, including cancer. Recent studies have shown that numerous lncRNAs play pivotal roles in the CRC metastasis, and reversing the expression of these lncRNAs through artificial means can reduce the malignant phenotype of metastatic CRC to some extent. This review summarizes the major mechanisms of lncRNAs in CRC metastasis and proposes lncRNAs as potential therapeutic targets for CRC and molecular markers for early diagnosis.

TRPM2-AS Promotes Bladder Cancer by Targeting miR-22-3p and Regulating GINS2 mRNA Expression

Background

Bladder cancer (BLCA) refers to the malignancy growth that spreads from the bladder linings to the bladder muscles. However, the impact of miR-22-3p and lncRNA TRPM2-AS on this tumor has generated divergent views in the literature. This research aimed to study the effects of lncRNA TRPM2-AS on BLCA and its interaction with miR-22-3p and GINS2 mRNA.

Methods

qRT-PCR was employed to measure the expression of TRPM2-AS, miR-22-3p and GINS2 mRNA in bladder tissues and cells. The subcellular localization of TRPM2-AS in T24 and 5637 cell lines was identified using a cell fractionation system. Luciferase assay, RIP assay and RNA pull-down assay were later performed to validate the direct binding relationship between TRPM2-AS, miR-22-3p and GINS2 mRNA. Several experiments were conducted to determine the viability, proliferation, colony formation and apoptosis of the cell lines.

Results

Findings indicated that TRPM2-AS was significantly upregulated in BLCA tissues and cell lines. Apart from that, it was observed that TRPM2-AS knockdown significantly inhibited the viability, proliferation and colony formation of BCLA cells, but it promoted the apoptosis of the BCLA cells. A significant downstream target of TRPM2-AS, miR-22-3p was found to show a lower expression level in BLCA tissues and cell lines. However, the inhibition of miR-22-3p considerably enhanced BLCA cell phenotypes. As well as discovering that GINS2 mRNA was a downstream target of miR-22-3p and was significantly upregulated in BLCA, experimental results also indicated that the knockdown of GINS2 suppressed BLCA cell phenotypes.

Conclusion

This research confirmed that TRPM2-AS could promote BCLA by binding to miR-22-3p to increase GINS2 expression. This novel interactome in BLCA cell lines might provide more insights into BLCA therapy.

MicroRNAs differential expression profile in metastatic colorectal cancer: A pilot study with literature review

BACKGROUND AND OBJECTIVES

Colorectal cancer is still one of the leading causes of cancer-related deaths worldwide and specific tools to improve disease assessment and treatment response are advocated. The aim of this study was to analyze miRNAs expression in metastatic and non-metastatic colorectal cancer, in order to identify reliable biomarkers suitable for prognosis, treatment and patient's monitoring.

MATERIAL AND METHODS

Among 25 patients (mean age 71 ± 12 years; Female/Male: 12/13) submitted to laparoscopic colorectal resection between August 2017 and February 2019, miRNAs were extracted from fresh frozen tissues of solid tumors. Gene expression's analysis arising from microarray technology was performed.

RESULTS

Pathological evaluation identified 15 metastatic patients (8 presenting with stage III and 7 with stage IV cancers) and 10 non-metastatic patients (4 presenting with stage I and 6 stage II cancers). Bioinformatic analysis of solid biopsies revealed 16 miRNAs (11 upregulated and 5 downregulated) differently expressed between metastatic and non-metastatic groups, with three miRNAs (miR-7515, miR-7109-5p and miR-6831-5p) never linked to colorectal cancer before.

CONCLUSIONS

Our study showed an association between miRNAs and metastatic colorectal cancer, suggesting their potential role as biomarkers for tumor management, if confirmed by further studies.

Long non-coding RNA LINC00858 aggravates the oncogenic phenotypes of ovarian cancer cells through miR-134-5p/RAD18 signaling

PURPOSE

Ovarian cancer is a common gynecological cancer. Herein, we focused on the function and probable mechanisms of LINC00858 in ovarian cancer.

METHODS

Real-time quantitative polymerase chain reaction (RT-qPCR) was employed for detecting the expression of LINC00858, miR-134-5p and RAD18 E3 ubiquitin protein ligase (RAD18). Cell proliferation, migration, invasion, epithelial-mesenchymal transition (EMT) and apoptosis were detected by cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), transwell, terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) and western bolt experiments, as appropriate. Interplays between LINC00858, miR-134-5p and RAD18 were detected by RNA immunoprecipitation (RIP), RNA pull down and luciferase reporter assays.

RESULTS

LINC00858 were up-regulated in ovarian cancer tissues and cells, and its expression was elevated in advanced samples compared to early ones. Knocking down LINC00858 inhibited cell proliferation, motility and EMT, but accelerated cell apoptosis in ovarian cancer. Moreover, could be sponged by LINC00858 sponged miR-134-5p to enhance RAD18 expression in ovarian cancer. Also, silenced RAD18 could also restrain oncogenic behaviors of ovarian cancer cells. Rescue experiments showed that overexpressing RAD18 reversed the effects caused by knocking down LINC00858 on cellular processes.

CONCLUSION

LINC00858 sequestered miR-134-5p to elevate RAD18 expression, resulting in aggravated development of ovarian cancer. This might provide promising targets for treating patients with ovarian cancer.

The circ-AMOTL1/ENO1 Axis Implicated in the Tumorigenesis of OLP-Associated Oral Squamous Cell Carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) may develop from a variety of oral potentially malignant disorders, but the mechanism of malignant transformation is still unknown. Among them, oral lichen planus (OLP) has a high prevalence. Previous studies have shown that α-enolase (ENO1) can promote cell proliferation and play an important role in tumorigenesis. In this study, we aim to explore the mechanism of ENO1 regulation in the process of OSCC tumorigenesis from OLP.

METHODS

ENO1 expression in tissues was determined by real-time quantitative PCR and immunohistochemistry. ENO1 was knocked down in cal-27 to observe the change in cell proliferation. Then, RNA-seq and bioinformatics analyses were conducted between OLP and OSCC samples. The expression of circ-AMOTL1, miRNA-22-3p, and miRNA-1294 was assessed using the real-time quantitative PCR. With knockdown and overexpression of circ-AMOTL1 in vitro, the change of ENO1 in the mRNA level was also assessed.

RESULTS

ENO1 was enhanced in the OSCC samples in comparison with OLP. Immunohistochemistry and real-time quantitative PCR results showed that ENO1 was significantly higher in OSCC tissue than in the OLP group, with a statistically significant difference (p<0.05). When ENO1 was knocked down in cal-27, cell proliferation was inhibited (p<0.05). The expression of miR-22-3p and miR-1294 was decreased in OSCC tissues, whereas ENO1 and circ-AMOTL1 increased. In an in vitro study, knockdown of circ-AMOTL1 resulted in a decrease of ENO1, while overexpression of circ-AMOTL1 led to an increase of ENO1 in the mRNA level.

CONCLUSION

We confirmed that ENO1 expression was elevated in OSCC and increased cell proliferation. In an in vitro study, ENO1 expression was promoted by circ-AMOTL1. ENO1 may play a role as a tumor-promoting gene in OSCC through the circ-AMOTL1/miR-22-3p/miR-1294 network. These novel findings may shed further light on the pathogenesis from OLP to OSCC and the potential precursor markers.

LINC00665/miR-9-5p/ATF1 is a novel axis involved in the progression of colorectal cancer

Long noncoding RNAs (lncRNAs) are abnormally expressed in many malignant tumors and involved in regulating the malignant phenotypes of cancer cells. However, the role of LINC00665 in colorectal cancer (CRC) and its regulatory mechanism remain unclear. In this study, real-time polymerase chain reaction (RT-PCR) was used to detect the expressions of LINC00665, miR-9-5p and activating transcription factor 1 (ATF1) mRNA in CRC tissues. The expression of ATF1 in CRC tissues was also detected by immunohistochemistry and Western blot. CCK-8 and colony formation assays were employed to detect cell proliferation. Cell cycle and apoptosis were detected by flow cytometry analysis. Scratch healing assay and Transwell test were exploited to detect cell migration and invasion. The targeting relationships between LINC00665 and miR-9-5p, and miR-9-5p and ATF1 were validated by dual luciferase reporter assay. We found that LINC00665 was significantly overexpressed in CRC tissues, and it was also negatively correlated with the expression of miR-9-5p and positively associated with the expression of ATF1. Besides, LINC00665 promoted the proliferation, migration and invasion of CRC cells, and inhibited cell apoptosis by sponging miR-9-5p. ATF1 was proved to be the downstream target of miR-9-5p and was indirectly regulated by LINC00665. Collectively, it is concluded that LINC00665 contributes to the progression of CRC by regulating miR-9-5p/ATF1 axis.

Long non-coding RNA LINC00858 inhibits colon cancer cell apoptosis, autophagy, and senescence by activating WNK2 promoter methylation

Accumulating evidence shows the involvement of long non-coding RNAs (lncRNAs) in tumorigenesis of many types of human cancers. However, the role of LINC00858 in colon cancer has not been fully elucidated. Therefore, we investigated the involvement of LINC00858 in the progression of colon cancer and identified its downstream targets. After examining the expression of LINC00858 in colon cancer tissues and cell lines, we then identified the possible interaction between LINC00858 and WNK lysine deficient protein kinase 2 (WNK2) by fluorescence in situ hybridization, RNA immunoprecipitation, chromatin immunoprecipitation, and RNA pull-down assays. Next, the role of the LINC00858/WNK2 axis was explored by evaluating the apoptosis, autophagy, and senescence of colon cancer cells in vitro after ectopic expression and depletion experiments in HCT116 cells. Moreover, a mouse xenograft model of HCT116 cells was established to verify the function of the LINC00858/WNK2 axis in vivo. There was high expression of LINC00858 and low expression of WNK2 in colon cancer tissues and cell lines. Silencing of LINC00858 promoted apoptosis, senescence, and autophagy in colon cancer cells. Additionally, the enrichment of WNK2 was promoted when LINC00858 bound to DNA methyltransferases. Furthermore, in vivo assays demonstrated that silencing of LINC00858 resulted in inhibited tumor growth by upregulating WNK2. In summary, LINC00858 acts as a tumor-promoting lncRNA in colon cancer by downregulating WNK2. Our results may provide novel targets for the treatment for colon cancer.

MicroRNAs in cancer therapy: Their involvement in oxaliplatin sensitivity/resistance of cancer cells with a focus on colorectal cancer

The resistance of cancer cells into chemotherapy has restricted the efficiency of anti-tumor drugs. Oxaliplatin (OX) being an anti-tumor agent/drug is extensively used in the treatment of various cancer diseases. However, its frequent application has led to chemoresistance. As a consequence, studies have focused in finding underlying molecular pathways involved in OX resistance. MicroRNAs (miRs) are short endogenous non-coding RNAs that are able to regulate vital biological mechanisms such as cell proliferation and cell growth. The abnormal expression of miRs occurs in pathological events, particularly cancer. In the present review, we describe the involvement of miRs in OX resistance and sensitivity. The miRs are able to induce the oncogene factors and mechanisms, resulting in stimulation OX chemoresistance. Also, onco-suppressor miRs can enhance the sensitivity of cancer cells into OX chemotherapy and trigger apoptosis and cell cycle arrest, leading to reduced viability and progression of cancer cells. MiRs can also enhance the efficacy of OX chemotherapy. It is worth mentioning that miRs affect various down-stream targets in OX resistance/sensitivity such as STAT3, TGF-β, ATG4B, FOXO1, LATS2, NF-κB and so on. By identification of these miRs and their upstream and down-stream mediators, further studies can focus on targeting them to sensitize cancer cells into OX chemotherapy and induce apoptotic cell death.

LINC00858 knockdown inhibits gastric cancer cell growth and induces apoptosis through reducing WNK2 promoter methylation

BACKGROUND

Emerging evidence indicates a regulatory role of long non-coding RNAs (lncRNAs) in the development of gastric cancer (GC), but the mechanisms underlying their function have remained largely unknown. Recent microarray-based expression profiling has led to the identification of a novel differentially expressed lncRNA, LINC00858, in GC. Subsequently, LINC00858 was found to be highly expressed in GC tissues and cells. This study was designed to clarify the functional role of LINC00858 in GC, including its effect on methylation of the WNK2 gene promoter and its downstream MAPK signaling pathway.

METHODS

After exogenous over-expression and knockdown of LINC00858 and the addition of a MAPK pathway inhibitor in GC cells, we explored the effects of LINC00858 and the MAPK signaling pathway on GC cell behavior using various in vitro and in vivo assays.

RESULTS

LINC00858 was found to negatively regulate WNK2 expression by enhancing its promoter methylation and to activate the MAPK signaling pathway. Moreover, we found that knockdown of LINC00858 or inhibition of the MAPK signaling pathway resulted in decreased GC cell growth, migration and invasion, as well as decreased cell cycle progression, along with increased apoptosis and decreased tumorigenicity.

CONCLUSIONS

Together, these findings indicate that silencing of LINC00858 increases WNK2 expression and inhibits the MAPK signaling pathway, thereby inhibiting GC growth and development. Our data highlight LINC00858 as a potential target in GC therapy.

Integrated analysis of lymphocyte infiltration-associated lncRNA for ovarian cancer via TCGA, GTEx and GEO datasets

Background

Abnormal expression of long non-coding RNAs (lncRNA) play a significant role in the incidence and progression of high-grade serous ovarian cancer (HGSOC), which is a leading cause of mortality among gynecologic malignant tumor patients. In this study, our aim is to identify lncRNA-associated competing endogenous RNA (ceRNA ) axes that could define more reliable prognostic parameters of HGSOC, and to investigate the lncRNAs’ potential mechanism of in lymphocyte infiltration.

Methods

The RNA-seq and miRNA expression profiles were downloaded from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) database; while for obtaining the differentially expressed lncRNAs (DELs), miRNAs (DEMs), and genes (DEGs), we used edgeR, limma and DESeq2. After validating the RNA, miRNA and gene expressions, using integrated three RNA expression profiles (GSE18520, GSE27651, GSE54388) and miRNA profile (GSE47841) from the Gene Expression Omnibus (GEO) database, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway analyses through ClusterProfiler. The prognostic value of these genes was determined with Kaplan–Meier survival analysis and Cox regression analysis. The ceRNA network was constructed using Cytoscape. The correlation between lncRNAs in ceRNA network and immune infiltrating cells was analyzed by using Tumor IMmune Estimation Resource (TIMER), and gene markers of tumor-infiltrating immune cells were identified using Spearman’s correlation after removing the influence of tumor purity.

Results

A total of 33 DELs (25 upregulated and eight downregulated), 134 DEMs (76 upregulated and 58 downregulated), and 1,612 DEGs (949 upregulated and 663 downregulated) were detected that could be positively correlated with overall survival (OS) of HGSOC. With the 1,612 analyzed genes, we constructed a ceRNA network, which indicated a pre-dominant involvement of the immune-related pathways. Furthermore, our data revealed that LINC00665 influenced the infiltration level of macrophages and dendritic cells (DCs). On the other hand, FTX and LINC00665, which may play their possible roles through the ceRNA axis, demonstrated a potential to inhibit Tregs and prevent T-cell exhaustion.

Conclusion

We defined several prognostic biomarkers for the incidence and progression of HGSOC and constructed a network for ceRNA axes; among which three were indicated to have a positive correlation with lymphocyte infiltration, namely: FTX-hsa-miR-150-5p-STK11, LINC00665-hsa-miR449b-5p-VAV3 and LINC00665-hsa-miR449b-5p-RRAGD.

Up-regulation of long noncoding RNA LINC00858 is associated with poor prognosis in gastric cancer

BACKGROUND

The present study aimed to investigated the expression pattern of long noncoding RNA LINC00858 (LINC00858) in gastric cancer (GC) patients and its feasibility as a new prognostic biomarker.

METHODS

We examined LINC00858 expression in GC tissues and matched normal tissues from 189 patients using a quantitative reverse transcription-polymerase chain reaction. The correlations of LINC00858 levels in GC patients with clinicopathologic features were analyzed using a chi-squared test. The influence of LINC00858 on the overall survival rate of GC patients was precisely calculated using Kaplan-Meier methods (log rank tests). Multivariate Cox regression assays were carried out for the identification of the independent risk factors for GC.

RESULTS

We observed that LINC00858 was distinctly up-regulated in GC tissues compared to adjacent non-tumor specimens (p < 0.01). Higher expression of LINC00858 in GC was found to be associated with TNM stage (p = 0.003) and lymphatic metastasis (p = 0.007). Using Kaplan-Meier assays, we found that patients with high expression levels of LINC00858 had a distinctly poor overall survival and disease-free survival compared to those with low expression levels of LINC00858 (p = 0.0102). Multivariate analyses confirmed that LINC00858 (p < 0.05) was an independent prognosis factor for GC patients.

CONCLUSIONS

The data obtained in our study indicate that LINC00858 may be used as a novel prognostic indicator in GC patients.

Long non‑coding RNA LINC00858 promotes TP53‑wild‑type colorectal cancer progression by regulating the microRNA‑25‑3p/SMAD7 axis

Long non-coding RNAs (lncRNAs) are involved in colorectal cancer (CRC) progression, however the mechanisms remain largely unknown. The present study aimed to reveal the role and possible molecular mechanisms of a new LNCRNA, LINC00858, in CRC. LINC00858 was increased in CRC tumor tissues, and patients with high LINC00858 expression had a shorter survival time. Knockdown of LINC00858 expression suppressed cell proliferation and induced G₀/G₁ cell cycle arrest and apoptosis in TP53-wild-type CRC cells. Subsequently, using Starbase v2.0 database, miR-25-3p was confirmed to interact with LINC00858 and was downregulated by LINC00858. Reduction of miR-25-3p expression with an inhibitor significantly attenuated the biological effects of LINC00858 knockdown in CRC cells. Furthermore, using TargetScan, SMAD7 was validated to interact with miR-25-3p and was downregulated by miR-25-3p. Lastly, the ectopic overexpression of SMAD7 rescued the suppressive effects of LINC00858 knockdown in CRC cells. Collectively, the results from the present study, to the best of our knowledge, firstly demonstrated a novel LINC00858/miR-25-3p/SMAD7 regulatory axis that promoted CRC progression, indicating LINC00858 as a promising therapeutic target for CRC.

Long non-coding RNA AGER-1 inhibits colorectal cancer progression through sponging miR-182

OBJECTIVE

Abundant evidence has illustrated that long non-coding RNA (lncRNA) plays a vital role in the regulation of tumor development and progression. Ectopic expression of a novel lncRNA, termed lnc-AGER-1, has been discovered in cancers, and this lncRNA was reported to exert an anti-tumor effect. However, its biological mechanism remains unelucidated in colorectal cancer.

METHODS

A total of 159 paired colorectal cancer specimens and adjacent tissues was applied to detect the expression of lnc-AGER-1 by the quantitative Real-time PCR (qRT-PCR), and a series of functional assays was executed to uncover the role of this lncRNA on colorectal cancer.

RESULTS

We found that the expression of lnc-AGER-1 in the tumor tissues was significantly down-regulated, while compared with adjacent normal tissues (0.0115 ± 0.0718 vs. 0.0347 ± 0.157; P < 0.0001). Also, lnc-AGER-1 was observably associated with clinical T status (r = -0.184, P = 0.024). Patients with advanced T status exerted a significantly lower level of lnc-AGER-1 than those with early T status (20.0% vs. 40.7%, P = 0.021). Over-expression of lnc-AGER-1 inhibited cell proliferation and migration efficiency, and induced cell cycle arrest at the G0/G1 phase, and promoted cell apoptosis. Further research proved that lnc-AGER-1 altered the expression of its neighbor gene, AGER, through acting as a competing endogenous RNA for miR-182 in colorectal cancer.

CONCLUSION

lnc-AGER-1 has a suppressive role in colorectal cancer development via modulating AGER, which may serve as a target for colorectal cancer diagnosis and treatment.

Comprehensive RNA Sequencing in Adenoma-Cancer Transition Identified Predictive Biomarkers and Therapeutic Targets of Human CRC

Specific molecular biomarkers for predicting the transition from colorectal adenoma to cancer have been identified, however, circular RNA (circRNA)-related signatures remain to be clarified. We carried out high-throughput RNA sequencing to determine the expression profiles of circRNAs, microRNAs (miRNAs), and mRNAs in human colorectal cancer (CRC), adenoma, and adjacent normal tissues. We identified 84 circRNAs, 41 miRNAs, and 398 mRNAs that were commonly differentially expressed in CRC and adenoma tissues compared with normal tissues. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and protein-protein interaction (PPI) analyses identified numerous cancer-related hub genes that might serve as potential therapeutic targets in CRC. Competing endogenous RNA (ceRNA) networks, including three circRNAs, three miRNAs, and 28 mRNAs were constructed, suggesting their potential role in cancer progression. Representative differentially expressed RNAs were validated by the Cancer Genome Atlas (TCGA) database and real-time PCR experiments. Receiver operating characteristic (ROC) curve analysis identified three circRNAs (hsa_circ_0049487, hsa_circ_0066875, and hsa_circ_0007444) as possible novel biomarkers predicting the transition from colonic adenoma to cancer. Overall, our findings may provide novel perspectives to clarify the mechanisms of the transition from premalignant adenoma to cancer and identify specific circRNA-related signatures with possible applications for the early diagnosis of and as potential therapeutic targets in CRC.

The role of YWHAZ in cancer: A maze of opportunities and challenges

YWHAZ (also named 14-3-3ζ) is a central hub protein for many signal transduction pathways and plays a significant role in tumor progression. Accumulating evidences have demonstrated that YWHAZ is frequently up-regulated in multiple types of cancers and acts as an oncogene in a wide range of cell activities including cell growth, cell cycle, apoptosis, migration, and invasion. Moreover, YWHAZ was reported to be regulated by microRNAs (miRNAs) or long non-coding RNAs and exerted its malignant functions by targeting downstream molecules like protein kinase, apoptosis proteins, and metastasis-related molecules. Additionally, YWHAZ may be a potential biomarker of diagnosis, prognosis and chemoresistance in several cancers. Targeting YWHAZ by siRNA, shRNA or miRNA was reported to have great help in suppressing malignant properties of cancer cells. In this review, we perform literature and bioinformatics analysis to reveal the oncogenic role and molecular mechanism of YWHAZ in cancer, and discuss the potential clinical applications of YWHAZ concerning diagnosis, prognosis, and therapy in malignant tumors.

LncRNA NNT-AS1 promotes non-small cell lung cancer progression through regulating miR-22-3p/YAP1 axis

Background

Lung cancer is the leading cause of cancer‐related mortality worldwide. Studies have demonstrated that long noncoding RNA nicotinamide nucleotide transhydrogenase‐antisense RNA1 (NNT‐AS1) functioned as an oncogene in most malignancies, including non‐small cell lung cancer (NSCLC). This study aimed to investigate the underlying mechanisms of NNT‐AS1 in NSCLC progression.

Methods

The levels of NNT‐AS1, miR‐22‐3p and Yes‐associated protein (YAP1) were detected by qRT‐PCR in NSCLC tissues and cells. Kaplan‐Meier analysis was conducted to analyze the correlation between NNT‐AS1 expression and overall survival of NSCLC patients. Cell proliferation was evaluated by MTT assay. Cell migration and invasion were assessed using transwell assay. The protein levels of YAP1 and EMT‐related proteins were detected by western blot. The molecular mechanism was predicted by starBase2.0 and validated by dual‐luciferase reporter assay or RNA pull‐down assay. Xenograft analysis was carried out to analyze tumor growth in vivo.

Results

We found that the levels of NNT‐AS1 and YAP1 were enhanced, while miR‐22‐3p expression was decreased in NSCLC tissues and cells. High NNT‐AS1 expression was correlated with poor prognosis. NNT‐AS1 knockdown impeded proliferation, migration, invasion and EMT of NSCLC cells. NNT‐AS1 targeted miR‐22‐3p, and YAP1 was a target of miR‐22‐3p in NSCLC cells. Furthermore, NNT‐AS1 facilitated the progression of NSCLC by regulating miR‐22‐3p/YAP1 axis. NNT‐AS1 knockdown repressed tumor growth in vivo.

Conclusion

NNT‐AS1 facilitated proliferation, migration, invasion and EMT of NSCLC cells by sponging miR‐22‐3p and regulating YAP1 expression, which might provide a potential biomarker and therapeutic target for NSCLC.

LINC00858 promotes colorectal cancer by sponging miR-4766-5p to regulate PAK2

OBJECTIVES

LncRNAs (long noncoding RNAs) have been reported to critically regulate colorectal cancer (CRC). We prospectively investigated effects and mechanisms of lncRNA LINC00858 on regulation of CRC progression.

METHODS

Expression of LINC00858 and its target were analyzed by quantitative real-time polymerase chain reaction and in situ hybridization. MTT and bromodeoxyuridine/5-bromo-2'-deoxyuridine (BrdU) staining to assess cell proliferation ability. Flow cytometry, wound healing, and transwell assays were conducted to evaluate cell apoptosis, migration, and invasion, respectively. Interaction between LINC00858 and its target was confirmed by luciferase activity assay and RNA immunoprecipitation. Subcutaneous xenotransplanted tumor model was established and employed to detect tumorigenic functions of LINC00858, and further evaluated by qRT-PCR, western blot, immunohistochemistry, and hematoxylin and eosin staining.

RESULTS

With a predicted poor prognosis, LINC00858 was upregulated in CRC patients. LINC00858 knockdown suppressed cell proliferation, invasion, and migration abilities, meanwhile induced cell apoptosis. Moreover, LINC00858 could target and inhibit the miR-4766-5p expression, thus promoting CRC progression. miR-4766-5p further suppressed serine/threonine kinase PAK2. Interestingly, interference of LINC00858 suppressed tumorigenic ability of CRC in vivo by downregulating PAK2.

CONCLUSIONS

LINC00858 promoted CRC progression by sponging miR-4766 to upregulate PAK2, shedding lights on LINC00858 as a potential therapeutic target candidate in CRC treatment from bench to clinic.

Long non-coding RNA LINC00858 exerts a tumor-promoting role in colon cancer via HNF4α and WNK2 regulation

BACKGROUND

Long non-coding RNAs (lncRNAs) are known to be frequently dysregulated in many types of human cancer. As yet, however, their roles in colon carcinogenesis have not been fully elucidated. In the current study, we assessed whether lncRNA LINC00858 may be involved in the progression of colon cancer and, in addition, investigated its downstream targets.

METHODS

LINC00858 expression in patient-derived colon cancer tissues and in colon cancer cell lines was determined using RT-qPCR. Also, relationships between LINC00858 expression and various clinicopathological characteristics were analyzed. The subcellular localization of LINC00858 was determined using fluorescence in situ hybridization. Interactions between LINC00858 and its downstream targets were first predicted by bioinformatic analysis and, subsequently, confirmed by RNA pull-down, RNA immunoprecipitation, chromatin immunoprecipitation and dual luciferase reporter assays. After in vitro upregulation of LINC00858 and/or silencing of WNK2 and hepatocyte nuclear factor 4α (HNF4α), the biological behavior of colon cancer cells was assessed using 5-ethynyl-2'-deoxyuridine (EdU) incorporation, Transwell invasion and tube formation assays. In vivo cancer growth was evaluated in nude mice.

RESULTS

We found that LINC00858 was highly expressed in primary colon cancer tissues and colon cancer cell lines, and was mainly located in the nucleus. High LINC00858 expression was found to correlate with a poor differentiation, advanced TNM stages and lymph node metastasis. Exogenous overexpression of LINC00858 promoted cell proliferation, invasion and migration of colon cancer cells, and facilitated angiogenesis and tumor growth. In addition, we found that LINC00858 can bind to and upregulate the nuclear transcription factor HNF4α, leading to WNK2 expression downregulation. This, in turn, resulted in the promotion of colon cancer cell growth.

CONCLUSIONS

From our data we conclude that LINC00858 acts as a tumor-promoting lncRNA in colon cancer by upregulating HNF4α and downregulating WNK2. Our results may provide novel targets for the treatment for colon cancer.

LINC00858 promotes retinoblastoma cell proliferation, migration and invasion by inhibiting miR-3182

The aim of the present study was to determine the role of long intergenic non-protein coding RNA 858 (LINC00858) in retinoblastoma (RB) and investigate the underlying molecular mechanisms. RB tissues and paracancerous tissues of 27 RB cases were obtained. RB cell lines (SO-RB50, Y79, HXO-RB44 and WERI-Rb1) and a normal retinal epithelial cell line (ARPE-19) were cultured for in vitro experiments. Batches of SO-RB50 and Y79 cells were assigned to groups transfected with small interfering RNA targeting LINC00858 (si-LINC00858 group), microRNA (miR)-3182 mimics or inhibitor, or the respective controls. A Cell Counting Kit-8 and Transwell assays were performed to assess the effect of the transfections on the proliferation, migration and invasion of SO-RB50 and Y79 cells. A luciferase reporter assay was performed using SO-RB50 cells to demonstrate the direct binding of LINC00858 and miR-3182. Reverse transcription-quantitative PCR was employed to detect LINC00858 and miR-3182 expression. Pearson correlation analysis was used to assess the correlation between the expression of LINC00858 and miR-3182. The results indicated that RB tissues and cells exhibited aberrantly elevated LINC00858 expression (P<0.05). Compared with those in the control-transfected group, SO-RB50 and Y79 cells of the si-LINC00858 group had a lower cell proliferation, as well as a lower number of migrated and invaded cells (all P<0.05). miR-3182 was proven to be a target gene of LINC00858, to be abnormally downregulated in RB tissues and cells (P<0.05) and to be negatively correlated with LINC00858 expression. Compared with those in the si-LINC00858 + inhibitor-negative control group, SO-RB50 and Y79 cells of the si-LINC00858 + miR-3182 inhibitor group exhibited a significantly higher relative proliferation, migration and invasion (all P<0.05). In conclusion, LINC00858 promoted RB cell proliferation, migration and invasion, at least partially by inhibiting miR-3182.

Long Noncoding RNA (lncRNA)-Mediated Competing Endogenous RNA Networks Provide Novel Potential Biomarkers and Therapeutic Targets for Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and has a high metastasis and reoccurrence rate. Long noncoding RNAs (lncRNAs) play an important role in CRC growth and metastasis. Recent studies revealed that lncRNAs participate in CRC progression by coordinating with microRNAs (miRNAs) and protein-coding mRNAs. LncRNAs function as competitive endogenous RNAs (ceRNAs) by competitively occupying the shared binding sequences of miRNAs, thus sequestering the miRNAs and changing the expression of their downstream target genes. Such ceRNA networks formed by lncRNA/miRNA/mRNA interactions have been found in a broad spectrum of biological processes in CRC, including liver metastasis, epithelial to mesenchymal transition (EMT), inflammation formation, and chemo-/radioresistance. In this review, we summarize typical paradigms of lncRNA-associated ceRNA networks, which are involved in the underlying molecular mechanisms of CRC initiation and progression. We comprehensively discuss the competitive crosstalk among RNA transcripts and the novel targets for CRC prognosis and therapy.

Identifying prognostic biomarkers in endometrial carcinoma based on ceRNA network

PURPOSE

Endometrial carcinoma (EC), a common gynecological malignancy with high incidence, affects the mental and physical health of women. Mounting evidence shows that long noncoding RNAs (lncRNAs), messenger RNAs (mRNAs), and microRNAs (miRNAs) have instrumental roles in various biological processes associated with the pathogenesis of EC. In this research, we intend to further study the mechanism of EC and the potential predictive markers of EC.

METHODS

First, we obtained original data of EC RNA transcripts from The Cancer Genome Atlas database and performed differential analysis. Subsequently, according to the miRcode online software, relationship pairs of lncRNA-miRNA were constructed, and miRNA-mRNA pairs were established based on miRDB, TargetScan, and miRTarBase. Then, we constructed the competing endogenous RNA (ceRNA) network based on lncRNA-miRNA and miRNA-mRNA pairs. To further explain the function of the ceRNA network and explore the potential prognostic markers, functional enrichment analysis, and survival analysis were carried out.

RESULTS

The research showed that there were 744 differential expression lncRNAs (DElncRNAs), 164 differential expression miRNAs (DEmiRNAs), and 2447 differential expression mRNAs (DEmRNAs) between EC tissues and normal tissues. Subsequently, we built 103 DEmiRNA-DEmRNA interaction pairs and 369 DElncRNA-DEmiRNA pairs. Then, we established the ceRNA network of EC, including 62 DElncRNAs, 26 DEmiRNAs, and 70 DEmRNAs. Moreover, 10 of 62 lncRNAs, 19 of 70 mRNAs, and 4 of 26 miRNAs that closely related to the survival of EC with P < .05 were obtained. Notably, based on this network, it was found that LINC00261-hsa-mir-31 pair and LINC00261-hsa-mir-211 target pairs could be used as the potential prognostic markers of EC.

CONCLUSION

This research recommended an available basis for the molecular mechanism of EC and prognosis prediction, which could help guide the subsequent treatments and predict the prognosis for patients with EC.