LncRNA MALAT1 modified progression of clear cell kidney carcinoma (KIRC) by regulation of miR-194-5p/ACVR2B signaling

Beyond the genome: MALAT1's role in advancing urologic cancer care

Urologic cancers (UCs), which include bladder, kidney, and prostate tumors, account for almost a quarter of all malignancies. Long non-coding RNAs (lncRNAs) are tissue-specific RNAs that influence cell growth, death, and division. LncRNAs are dysregulated in UCs, and their abnormal expression may allow them to be used in cancer detection, outlook, and therapy. With the identification of several novel lncRNAs and significant exploration of their functions in various illnesses, particularly cancer, the study of lncRNAs has evolved into a new obsession. MALAT1 is a flexible tumor regulator implicated in an array of biological activities and disorders, resulting in an important research issue. MALAT1 appears as a hotspot, having been linked to the dysregulation of cell communication, and is intimately linked to cancer genesis, advancement, and response to treatment. MALAT1 additionally operates as a competitive endogenous RNA, binding to microRNAs and resuming downstream mRNA transcription and operation. This regulatory system influences cell growth, apoptosis, motility, penetration, and cell cycle pausing. MALAT1's evaluation and prognosis significance are highlighted, with a thorough review of its manifestation levels in several UC situations and its association with clinicopathological markers. The investigation highlights MALAT1's adaptability as a possible treatment target, providing fresh ways for therapy in UCs as we integrate existing information The article not only gathers current knowledge on MALAT1's activities but also lays the groundwork for revolutionary advances in the treatment of UCs.

Activin receptors in human cancer: Functions, mechanisms, and potential clinical applications

Activins are members of the transforming growth factor-β (TGF-β) superfamily and act as key regulators in various physiological processes, such as follicle and embryonic development, as well as in multiple human diseases, including cancer. They have been established to signal through three type I and two type II serine/threonine kinase receptors, which, upon ligand binding, form a final signal-transducing receptor complex that activates downstream signaling and governs gene expression. Recent research highlighted the dysregulation of the expression or activity of activin receptors in multiple human cancers and their critical involvement in cancer progression. Furthermore, expression levels of activin receptors have been associated with clinicopathological features and patient outcomes across different cancers. However, there is currently a paucity of comprehensive systematic reviews of activin receptors in cancer. Thus, this review aimed to consolidate existing knowledge concerning activin receptors, with a primary emphasis on their signaling cascade and emerging biological functions, regulatory mechanisms, and potential clinical applications in human cancers in order to provide novel perspectives on cancer prognosis and targeted therapy.

A comprehensive database of exosome molecular biomarkers and disease-gene associations

Exosomes play a crucial role in intercellular communication and can be used as biomarkers for diagnostic and therapeutic clinical applications. However, systematic studies in cancer-associated exosomal nucleic acids remain a big challenge. Here, we developed ExMdb, a comprehensive database of exosomal nucleic acid biomarkers and disease-gene associations curated from published literature and high-throughput datasets. We performed a comprehensive curation of exosome properties including 4,586 experimentally supported gene-disease associations, 13,768 diagnostic and therapeutic biomarkers, and 312,049 nucleic acid subcellular locations. To characterize expression variation of exosomal molecules and identify causal factors of complex diseases, we have also collected 164 high-throughput datasets, including bulk and single-cell RNA sequencing (scRNA-seq) data. Based on these datasets, we performed various bioinformatics and statistical analyses to support our conclusions and advance our knowledge of exosome biology. Collectively, our dataset will serve as an essential resource for investigating the regulatory mechanisms of complex diseases and improving the development of diagnostic and therapeutic biomarkers.

CircGNB1 facilitates the malignant phenotype of GSCs by regulating miR-515-5p/miR-582-3p-XPR1 axis

Glioma is the most common and aggressive primary malignant brain tumor. Circular RNAs (circRNAs) and RNA-binding proteins (RBPs) have been verified to mediate diverse biological behaviors in various human cancers. Therefore, the aim of this study was to explore a novel circRNA termed circGNB1 and elucidate relative molecular mechanism in functional phenotypes, which might be a potential prognostic biomarker and therapeutic approach for glioma. CircGNB1 was upregulated in glioma and closely associated with the low poor prognosis. Functional assays demonstrated that circGNB1 overexpression promoted glioma stem cells (GSCs) viability proliferation, invasion, and neurosphere formation. Mechanistically, circGNB1 upregulated the expression of oncogene XPR1 via sponging miR-515-5p and miR-582-3p. The following experiments proved XPR1 could promote the malignant phenotype of GSCs via upregulating IL6 expression and activating JAK2/STAT3 signaling. Moreover, the RNA binding protein IGF2BP3 could bind to and maintain the stability of circGNB1, thus promoting the effects of circGNB1 on GSCs. Our study reveals that circGNB1 plays a crucial role in promoting tumorigenesis and malignant progression in glioma, which provides a promising cancer biomarker.

A New Signature of Sarcoma Based on the Tumor Microenvironment Benefits Prognostic Prediction

Sarcomas are a group of malignant tumors derived from mesenchymal tissues that display complex and variable pathological types. The impact of the immune properties of the tumor microenvironment (TME) on the prognosis, treatment, and management of sarcomas has attracted attention, requiring the exploration of sensitive and accurate signatures. In this study, The Cancer Genome Atlas (TCGA) database was searched to screen for an RNA sequencing dataset, retrieving 263 sarcoma and 2 normal samples with survival data. Genes associated with immune regulation in sarcomas were retrieved from the Tumor Immune Estimation Resource database to estimate tumor purity and immune cell infiltration levels. The samples were then divided into the immune-high and immune-low groups. Then, we screened for differentially expressed genes (DEGs) between the two groups. The intersection between immune-related genes and DEGs was then determined. Univariate Cox and least absolute shrinkage and selection operator analyses were used to select ideal genes for prognostic prediction and subsequent construction of a risk signature. A survival analysis was performed to reveal the dissimilarity in survival between the high- and low-score groups. Finally, a nomogram was generated to verify the accuracy and reliability of the signature. Through Estimation of STromal and Immune cells in MAlignant Tumour tissues using Expression (ESTIMATE) analysis, high ESTIMATE, and low tumor purity were significantly associated with a favorable prognosis. Moreover, a total of 5259 DEGs were retrieved, the majority of which were downregulated. In total, 590 immune-associated genes overlapped with the DEGs, among which nine hub genes were identified. Finally, two candidate genes, ACVR2B and NFYA, were identified, based on which a risk signature was constructed. The risk signature constructed in this study is accurate and reliable for the prognostic prediction and phenotyping of sarcomas.

A review on the role of long non-coding RNA and microRNA network in clear cell renal cell carcinoma and its tumor microenvironment

Renal cell carcinoma (RCC) is the second lethal urogenital malignancy with the increasing incidence and mortality in the world. Clear cell renal cell carcinoma (ccRCC) is one major subtype of RCC, which accounts for about 70 to 80% of all RCC cases. Although many innovative therapeutic options have emerged during the last few decades, the efficacy of these treatments for ccRCC patients is very limited. To date, the prognosis of patients with advanced or metastatic ccRCC is still poor. The 5-year survival rate of these patients remains less than 10%, which mainly attributes to the complexity and heterogeneity of the tumor microenvironment (TME). It has been demonstrated that long non-coding RNAs (lncRNAs) perform an indispensable role in the initiation and progression of various tumors. They mostly function as sponges for microRNAs (miRNAs) to regulate the expression of target genes, finally influence the growth, metastasis, apoptosis, drug resistance and TME of tumor cells. However, the role of lncRNA/miRNA/mRNA axis in the TME of ccRCC remains poorly understood. In this review, we summarized the biological function of lncRNA/miRNA/mRNA axis in the pathogenesis of ccRCC, then discussed how lncRNA/miRNA/mRNA axis regulate the TME, finally highlighted their potential application as novel biomarkers and therapeutic targets for ccRCC.

Identification of miRNAs and related hub genes associated with the triple negative breast cancer using integrated bioinformatics analysis and in vitro approach

Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype generally associated with younger women. Due to the lack of suitable drugable targets in TNBC, the microRNAs are considered as a better hope as therapeutic agents for the management of the disease. In this study, we identified differentially expressed miRNAs (DEMs) and associated hub genes in TNBC microarray data (GSE38167, GSE60714, and GSE10833) using bioinformatics tools. The identified miRNAs and genes were validated in the TNBC cell line model (MDA-MB-231) compared with the normal breast cells (MCF-10A) using the qRT-PCR technique. False-positive DEMs were avoided by comparing the DEMs profile of TNBC and triple positive breast cancer (TPBC) cell line model (BT474) compared with the MCF-10A cells data. In addition, we studied the effect of anticancer phytochemicals on the differential expression of miRNAs and genes in MDA-MB-231 cells. Furthermore, target predictions, functional enrichment and KEGG pathway analysis, mutation and copy number alterations, and overall survival analysis of DEMs in TNBC sample was investigated using standard computational tools. The study identifies first time the association of hsa-miR-1250, has-miR-1273, and has-miR-635 with the TNBC. DEMs showed significant association with the Wnt, ErbB, PI3-Akt and cAMP signaling pathways having clinical implications in TNBC tumorigenesis. The DEMs and hub genes (HOXC6 and ACVR2B) showed survival disadvantages in TNBC patients. In summary, the identified miRNAs and hub genes show important implications in TNBC tumorigenesis and patient survival. We recommend further experimental studies on pathophysiological mechanism of the identified miRNAs and hub genes in TNBC.Communicated by Ramaswamy H. Sarma.

Correlation between Genes of the ceRNA Network and Tumor-Infiltrating Immune Cells and Their Biomarker Screening in Kidney Renal Clear Cell Carcinoma

This study aimed to using bioinformatics tools, qPCR, and the immunohistochemical analysis to find out factors related to the early diagnosis and prognosis of kidney renal clear cell carcinoma (KIRC). The expression profiles of lncRNA, miRNA, and mRNA of KIRC were downloaded from The Cancer Genome Atlas database. A ceRNA regulatory network was constructed based on the interaction between these three differentially expressed genes. The CIBERSORT deconvolution algorithm was used to analyze the differential distribution of 22 types of immune cells. The Kaplan–Meier survival and Cox analyses were used to screen genes of the ceRNA network and also immune cell subtypes related to the clinical and prognostic prediction of KIRC. Co-expression regulatory relationships were found among LINC01426, LINC00894, CCNA2, L1 cell adhesion molecule (L1CAM), and T follicular helper cells, which served as potential biomarkers. The results of quantitative reverse transcriptase-polymerase chain reaction showed that LINC01426 was upregulated while L1CAM was downregulated in KIRC, but no difference was found in the expression levels of LINC00894 and CCNA2 in cancer and adjacent samples. The immunohistochemical analysis showed that T follicular helper cells were more concentrated in core tissues and metastases of KIRC. In a word, co-expression relationships were found among LINC01426, L1CAM, and T follicular helper cells, and they may serve as biomarkers for early diagnosis and prognostic evaluation of KIRC.

Emerging role of lncRNAs in drug resistance mechanisms in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) originates in the squamous cell lining the mucosal surfaces of the head and neck region, including the oral cavity, nasopharynx, tonsils, oropharynx, larynx, and hypopharynx. The heterogeneity, anatomical, and functional characteristics of the patient make the HNSCC a complex and difficult-to-treat disease, leading to a poor survival rate and a decreased quality of life due to the loss of important physiologic functions and aggressive surgical injury. Alteration of driver-oncogenic and tumor-suppressing lncRNAs has recently been recently in HNSCC to obtain possible biomarkers for diagnostic, prognostic, and therapeutic approaches. This review provides current knowledge about the implication of lncRNAs in drug resistance mechanisms in HNSCC. Chemotherapy resistance is a major therapeutic challenge in HNSCC in which lncRNAs are implicated. Lately, it has been shown that lncRNAs involved in autophagy induced by chemotherapy and epithelial–mesenchymal transition (EMT) can act as mechanisms of resistance to anticancer drugs. Conversely, lncRNAs involved in mesenchymal–epithelial transition (MET) are related to chemosensitivity and inhibition of invasiveness of drug-resistant cells. In this regard, long non-coding RNAs (lncRNAs) play a pivotal role in both processes and are important for cancer detection, progression, diagnosis, therapy response, and prognostic values. As the involvement of more lncRNAs is elucidated in chemoresistance mechanisms, an improvement in diagnostic and prognostic tools could promote an advance in targeted and specific therapies in precision oncology.

LINC00174 promotes cell proliferation and metastasis in renal clear cell carcinoma by regulating miR-612/FOXM1 axis

BACKGROUND

Kidney renal clear cell carcinoma (KIRC) is the most common pathological subtype of kidney tumor. Reportedly, LINC00174 is a key regulator in cancer progression. This study aims to clarify the role and molecular mechanism of LINC00174 in the progression of KIRC.

METHODS

LINC00174 expression in KIRC and its prognostic value were analyzed by bioinformatics. LINC00174, miR-612 and FOXM1 mRNA expression levels in KIRC clinical samples and cell lines were detected by qRT-PCR. After LINC00174 was overexpressed or knocked down, CCK-8, BrdU and Transwell assays were adopted to evaluate the proliferation and metastatic potential of KIRC cells. Bioinformatics and dual luciferase reporter assays were employed to validate the targeting relationship between miR-612 and LINC00174 or FOXM1 mRNA, respectively. Western blot assay was performed to detect FOXM1 protein expression in KIRC cells.

RESULTS

LINC00174 expression and FOXM1 expression were up-regulated in 42 cases of KIRC tissues (P < 0.001), while miR-612 expression was down-regulated (P < 0.001). LINC00174 overexpression or miR-612 inhibitor promoted the viability and proliferation of KIRC cells (P < 0.01). Migration and invasion of KIRC cells were promoted when the cells were transfected with LINC00174 overexpression or miR-612 inhibitor (P < 0.05). LINC00174 can competitively bind with miR-612 to repress the expression of miR-612, in turn up-regulate the expression of FOXM1 mRNA.

CONCLUSION

LINC00174 facilitates the proliferation and metastatic potential of KIRC cells via regulating the miR-612/FOXM1 axis.

Pan-cancer analysis of microRNA expression profiles highlights microRNAs enriched in normal body cells as effective suppressors of multiple tumor types: A study based on TCGA database

BACKGROUND

MicroRNAs (miRNAs) are frequently deregulated in various types of cancer. While antisense oligonucleotides are used to block oncomiRs, delivery of tumour-suppressive miRNAs holds great potential as a potent anti-cancer strategy. Here, we aim to determine, and functionally analyse, miRNAs that are lowly expressed in various types of tumour but abundantly expressed in multiple normal tissues.

METHODS

The miRNA sequencing data of 14 cancer types were downloaded from the TCGA dataset. Significant differences in miRNA expression between tumor and normal samples were calculated using limma package (R programming). An adjusted p value < 0.05 was used to compare normal versus tumor miRNA expression profiles. The predicted gene targets were obtained using TargetScan, miRanda, and miRDB and then subjected to gene ontology analysis using Enrichr. Only GO terms with an adjusted p < 0.05 were considered statistically significant. All data from wet-lab experiments (cell viability assays and flow cytometry) were expressed as means ± SEM, and their differences were analyzed using GraphPad Prism software (Student's t test, p < 0.05).

RESULTS

By compiling all publicly available miRNA profiling data from The Cancer Genome Atlas (TCGA) Pan-Cancer Project, we reveal a small set of tumour-suppressing miRNAs (which we designate as 'normomiRs') that are highly expressed in 14 types of normal tissues but poorly expressed in corresponding tumour tissues. Interestingly, muscle-enriched miRNAs (e.g. miR-133a/b and miR-206) and miRNAs from DLK1-DIO3 locus (e.g. miR-381 and miR-411) constitute a large fraction of the normomiRs. Moreover, we define that the CCCGU motif is absent in the oncomiRs' seed sequences but present in a fraction of tumour-suppressive miRNAs. Finally, the gain of function of candidate normomiRs across several cancer cell types indicates that miR-206 and miR-381 exert the most potent inhibition on multiple cancer types in vitro.

CONCLUSION

Our results reveal a pan-cancer set of tumour-suppressing miRNAs and highlight the potential of miRNA-replacement therapies for targeting multiple types of tumour.

Identification of Novel Prognostic Signatures for Clear Cell Renal Cell Carcinoma Based on ceRNA Network Construction and Immune Infiltration Analysis

Objective. Clear cell renal cell carcinoma (ccRCC) carries significant morbidity and mortality globally and is often resistant to conventional radiotherapy and chemotherapy. Immune checkpoint blockade (ICB) has received attention in ccRCC patients as a promising anticancer treatment. Furthermore, competitive endogenous RNA (ceRNA) networks are crucial for the occurrence and progression of various tumors. This study was aimed at identifying reliable prognostic signatures and exploring potential mechanisms between ceRNA regulation and immune cell infiltration in ccRCC patients. Methods and Results. Gene expression profiling and clinical information of ccRCC samples were obtained from The Cancer Genome Atlas (TCGA) database. Through comprehensive bioinformatic analyses, differentially expressed mRNAs (DEmRNAs; $n=131$ ), lncRNAs (DElncRNAs; $n=12$ ), and miRNAs (DEmiRNAs; $n=25$ ) were identified to establish ceRNA networks. The CIBERSORT algorithm was applied to calculate the proportion of 22 types of tumor-infiltrating immune cells (TIICs) in ccRCC tissues. Subsequently, univariate Cox, Lasso, and multivariate Cox regression analyses were employed to construct ceRNA-related and TIIC-related prognostic signatures. In addition, we explored the relationship between the crucial genes and TIICs via coexpression analysis, which revealed that the interactions between MALAT1, miR-1271-5p, KIAA1324, and follicular helper T cells might be closely correlated with the progression of ccRCC. Ultimately, we preliminarily validated that the potential MALAT1/miR-1271-5p/KIAA1324 axis was consistent with the ceRNA theory by qRT-PCR in the ccRCC cell lines. Conclusion. On the basis of the ceRNA networks and TIICs, we constructed two prognostic signatures with excellent predictive value and explored possible molecular regulatory mechanisms, which might contribute to the improvement of prognosis and individualized treatment for ccRCC patients.

LncRNAs in the Regulation of Genes and Signaling Pathways through miRNA-Mediated and Other Mechanisms in Clear Cell Renal Cell Carcinoma

The fundamental novelty in the pathogenesis of renal cell carcinoma (RCC) was discovered as a result of the recent identification of the role of long non-coding RNAs (lncRNAs). Here, we discuss several mechanisms for the dysregulation of the expression of protein-coding genes initiated by lncRNAs in the most common and aggressive type of kidney cancer-clear cell RCC (ccRCC). A model of competitive endogenous RNA (ceRNA) is considered, in which lncRNA acts on genes through the lncRNA/miRNA/mRNA axis. For the most studied oncogenic lncRNAs, such as HOTAIR, MALAT1, and TUG1, several regulatory axes were identified in ccRCC, demonstrating a number of sites for various miRNAs. Interestingly, the LINC00973/miR-7109/Siglec-15 axis represents a novel agent that can suppress the immune response in patients with ccRCC, serving as a valuable target in addition to the PD1/PD-L1 pathway. Other mechanisms of action of lncRNAs in ccRCC, involving direct binding with proteins, mRNAs, and genes/DNA, are also considered. Our review briefly highlights methods by which various mechanisms of action of lncRNAs were verified. We pay special attention to protein targets and signaling pathways with which lncRNAs are associated in ccRCC. Thus, these new data on the different mechanisms of lncRNA functioning provide a novel basis for understanding the pathogenesis of ccRCC and the identification of new prognostic markers and targets for therapy.

Comprehensive analysis of lncRNAs as biomarkers for diagnosis, prognosis, and treatment response in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common histological type of renal carcinoma and has a high recurrence rate and poor outcome. Accurate patient risk stratification based on genetic markers can help to identify the high-risk patient for early and further treatments and would promote patient survival. Long non-coding RNAs (lncRNAs) have attracted widespread attention as biomarkers for early diagnosis, treatment, and prognosis because of their high specificity and sensitivity. Here, we performed a systematic search in NCBI PubMed and found 44 lncRNAs as oncogenes, 18 lncRNAs as tumor suppressors, 199 lncRNAs as diagnostic biomarkers, 62 lncRNAs as prognostic biomarkers, and 3 lncRNAs as predictive biomarkers for ccRCC. We also comprehensively discuss the biological functions and molecular regulatory mechanisms of lncRNAs in ccRCC. Overall, the present study is a systemic analysis to assess the expression and clinical value of lncRNAs in ccRCC, and lncRNAs hold promise to be diagnostic, prognostic, and predictive biomarkers.

Potential prognostic biomarkers related to immunity in clear cell renal cell carcinoma using bioinformatic strategy

The clear cell renal cell carcinoma (ccRCC) is the main pathological subtype of renal cell carcinoma. Immune system evasion, one hallmark of cancer, contributes to cancer cells in escaping from the attack of immune cells. In order to identify potential prognostic biomarkers in ccRCC patients and immune cells fraction, we collected and downloaded profiles from The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) database. We obtained 2 modules significantly associated with tumor stage and immune cells; functional enrichment analysis showed that genes in the module ‘yellow’ were significantly enriched in proteins targeting to membrane and ribosome, as well as the oxidative phosphorylation pathway, while genes in the module ‘green’ mainly participate in molecular functions associated with immunity like activation of T cells. Four LncRNAs (LINC00472, AL590094.1, AL365203.3, and AC147651.3) and RPL27A and RPL22L1 in the module ‘yellow’ and two lncRNAs (LINC00426 and AC129507.2) and five protein-coding genes (CSF1, NOD2, ITGAE, CD7, and PDCD1) in the module ‘green’ represented independent prognostic values in patients with ccRCC. Expression of LINC0042, NOD2, CD7, and PDCD1 were significantly correlated with ratio of immune cells (like T cells CD8 and resting mast cells). LINC00426, with significant correlation with immune cell fraction, shows potential prognostic value in ccRCC patients. Our findings provide a strategy in exploring biomarkers with prognostic significance and significant association with the fraction of immune cells.

Ferroptosis-Related Gene Signature Accurately Predicts Survival Outcomes in Patients With Clear-Cell Renal Cell Carcinoma

As a type of regulated cell death induced by Ras selective lethal (RSL) compounds such as erasti, ferroptosis is characterized by iron-dependent lipid peroxide accumulation to lethal levels. At present, little is known about the role of ferroptosis-related genes in clear-cell renal cell carcinoma (ccRCC). In the present study, the expression data of ferroptosis-related genes in ccRCC were obtained from the Cancer Genome Atlas (TCGA), and COX regression analysis was performed to construct a risk model of ferroptosis prognostic signature. The GEO database was used to verify the accuracy of the model. The following findings were made: the results reveal that the prognostic signature constructed by 11 ferroptosis genes (CARS, CD44, DPP4, GCLC, HMGCR, HSPB1, NCOA4, SAT1, PHKG2, GOT1, HMOX1) was significantly related to the overall survival (OS) of ccRCC patients based on the lowest Akaike information criterion (AIC); multivariate analysis indicates that ferroptosis-related gene prognostic signature was an independent prognostic factor in ccRCC patients; the calibration curve and c-index value (0.77) demonstrate that the nomogram with the signature could predict the survival of ccRCC patients; and enrichment analysis shows that the high-risk group were enriched in humoral immunity and receptor interaction pathways. The aforementioned findings indicate that the ferroptosis-related gene signature can accurately predict the prognosis of ccRCC patients and provide valuable insights for individualized treatment.

Long non-coding RNA SUMO1P3 promotes tumour progression by regulating cell proliferation and invasion in glioma

Gliomas account for 50% of primary brain tumours in the central nervous system. Small ubiquitin-like modifier 1 pseudogene 3 (SUMO1P3), a newly identified long non-coding RNA (lncRNA), serves an oncogenic role in various types of cancer. The aim of the present study was to investigate the effect of SUMO1P3 on glioma progression. The results demonstrated that SUMO1P3 expression was upregulated in glioma tissues and cell lines. Furthermore, SUMO1P3 was associated with a poor overall survival of patients with glioma. The results of the in vitro cell proliferation and flow cytometry assays demonstrated that SUMO1P3-knockdown suppressed cell proliferation and cell cycle. The results of the wound healing and Transwell assays demonstrated that SUMO1P3-knockdown significantly repressed cell migration and invasion. In addition, SUMO1P3 promoted glioma by regulating the expression levels of β-catenin, cyclin-D1, N-cadherin and E-cadherin. Overall, the results of the present study suggested that SUMO1P3 may act as an oncogene by regulating cell proliferation, cell cycle, cell migration and invasion in glioma, and may represent a novel diagnostic biomarker and therapeutic target for glioma.

The role of a ceRNA regulatory network based on lncRNA MALAT1 site in cancer progression

As a type of non-coding RNA of more than 200 nucleotides, long non-coding RNAs(lncRNAs) lack protein coding ability and can regulate gene expression. MicroRNAs(miRNAs), which are also non-coding RNAs, are short single-stranded RNAs, usually composed of 18-23 nucleotides. MiRNAs inhibits gene expression by specifically binding to the 3'-UTR of downstream target mRNAs and can function as oncogenes or suppressor oncogenes to regulate the occurrence and development of cancer. LncRNAs can function as competitive endogenous RNAs that bind to miRNAs, resulting in the recovery of downstream mRNA expression and activity. The regulatory network existing between lncRNAs, miRNAs and mRNAs regulates a variety of biological processes, including cell proliferation, apoptosis, migration and invasion as well as cell-cycle arrest. Disruption of the ceRNA network affects cell growth and development and often leads to various diseases, especially cancer. The lncRNA MALAT1, which is located on chromosome 11q13, contains more than 8000 nucleotides and is implicated in the occurrence and development of many cancers. Here, we review the impact of the ceRNA network and the lncRNA MALAT1 in cancer.

lncRNA‑MALAT1 promotes high glucose‑induced H9C2 cardiomyocyte pyroptosis by downregulating miR‑141‑3p expression

Diabetic cardiomyopathy (DCM) is caused by diabetes and can result in heart failure. Long non-coding RNAs (lncRNAs) have been demonstrated to be closely associated with DCM development. The present study aimed to investigate whether lncRNA-metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) altered high glucose (HG)-induced H9C2 cardiomyocyte pyroptosis by targeting microRNA (miR)-141-3p. H9C2 cells were treated with normal glucose (NG) or HG. lncRNA-MALAT1 and miR-141-3p expression levels were determined via reverse transcription-quantitative PCR (RT-qPCR). MALAT1 and miR-141-3p knockdown and overexpression were established and confirmed via RT-qPCR. The association between MALAT1 expression and miR-141-3p expression, as well as the induction of pyroptosis and gasdermin D (GSDMD)-N expression were evaluated by performing dual luciferase reporter, TUNEL staining and immunofluorescence staining assays, respectively. Western blotting was conducted to measure the expression levels of pyroptosis-associated proteins, including apoptosis-associated speck-like protein, GSDMD-N, caspase-1, nucleotide oligomerization domain-like receptor protein 3 and GSDMD. MALAT1 mRNA expression levels were significantly increased, whereas miR-141-3p expression levels were significantly decreased in HG-treated H9C2 cells compared with the NG group. Compared with the HG group, MALAT1 overexpression significantly reduced miR-141-3p expression levels, increased the rate of TUNEL positive cells and upregulated the expression levels of pyroptosis-associated proteins. MALAT1 knockdown displayed the opposite effect on the rate of TUNEL positive cells and the expression levels of pyroptosis-associated proteins. Furthermore, the rate of TUNEL positive cells, and GSDMD-N and pyroptosis-associated protein expression levels were significantly reduced by miR-141-3p overexpression in MALAT1-overexpression H9C2 cells. The results indicated that compared with NG treatment, HG treatment increased MALAT1 expression levels and decreased miR-141-3p expression levels in H9C2 cells. Therefore, the present study suggested that lncRNA-MALAT1 targeted miR-141-3p to promote HG-induced H9C2 cardiomyocyte pyroptosis.

Silencing circ-USP1 protects the renal tubular from kidney injury induced by hypoxia via modulating miR-194-5p/DNMT3A axis in acute renal allografts

Recent studies indicate that circular RNAs are involved in dysregulation of kidney injury. Nevertheless, the underlying mechanisms remain largely unclear. Therefore, this study sought to investigate the role of circ-USP1 in the pathogenesis of early renal allografts. Thirty-two male C57BL/6J mice aged between 6 and 8 weeks were divided into the sham and allograft groups. Thereafter, the association between miR-194-5p, circ-USP1 and DNMT3A was confirmed using a combination of bioinformatics and the luciferase reporter gene assay. Additionally, the expression of circ-USP1, miR-194-5p and DNMT3A mRNA was detected through qPCR. Afterwards, the Western blot assay was performed to examine the expression of DNMT3A protein. Finally, the TUNEL assay was conducted to determine the rate of apoptosis in DNMT3A cells. The expression of circ-USP1 increased, while that of miR-194-5p decreased in renal allografts. Additionally, silencing circ-USP1 reduced kidney injuries caused by renal allografts in mice. Moreover, miR-194-5p was a target for circ-USP1, and DNMT3A was a target of miR-194-5p. Finally, it was shown that silencing circ-USP1 reduced DNMT3A expression in the kidney of mice that received renal allografts. Circ-USP1 functions as a competing endogenous RNA for miR-194-5p. This occurs in order to regulate DNMT3A expression in kidney injury induced by hypoxia in acute renal allografts.

Proposal of a Panel of Genes Identified by miRNA Profiling as Candidate Prognostic Biomarkers in Lung Carcinoids

AIM

To validate the prognostic role of a panel of genes previously uncovered by our group to be specific targets of miRNAs differentially expressed in lung carcinoids with aggressive pathological features.

METHODS

Four genes, namely, cyclic AMP response element binding protein-1 (CREBP1), activin A receptor type 2B (ACVR2B), LIM homeobox 2 (LHX2), and Krüppel-like factor 12 (KLF12), were identified in a previous study by our group using in silico analysis to be regulated by 3 miRNAs (miR-409-3p, miR-409-5p, and miR-431-5p) that were shown to be downregulated in aggressive lung carcinoids. These genes were analyzed using real-time PCR in a cohort of 102 lung carcinoids. Fifty high-grade lung carcinomas served as control group. Their expression was correlated with the expression of miR-409-3p, miR-409-5p, and miR-431-5p and with clinical pathological parameters and disease-free survival.

RESULTS

The expression of all but CREBP1 gene was significantly different between lung carcinoids and high-grade neuroendocrine carcinomas. ACVR2B and LHX2 were significantly inversely correlated with miR-409-3p and miR-409-5p. High levels of ACVR2B and LHX2 were significantly associated with atypical histotype, high tumor grade, and higher proliferation Ki-67 index (all p < 0.05). Low levels of KLF12 were significantly associated with the presence of necrosis and positive nodal status (all p < 0.05). Finally, low KLF12 expression was associated with shorter disease-free survival in lung carcinoids as a whole and in atypical carcinoids, only (all p < 0.001).

CONCLUSIONS

ACVR2B, LHX2, and KFL12 are novel potential biomarkers associated with aggressive features in lung carcinoids.

LncRNA PVT1 accelerates malignant phenotypes of bladder cancer cells by modulating miR-194-5p/BCLAF1 axis as a ceRNA

Background: Numerous studies proved that long non-coding RNA (lncRNA) is involved in the progression of multifarious diseases, especially in some carcinomas. As a potential tumor biomarker, plasmacytoma variant translocation 1 gene (PVT1) is involved in the development and progression of multifarious cancers. Nevertheless, the intrinsic and concrete molecular mechanism of PVT1 in bladder cancer still remained unclear, which is also the dilemma faced in many non-coding RNA studies.

Results: Our research revealed that PVT1 was significantly higher expression in bladder carcinoma specimens and cell lines. Further experiments indicated that knockdown or overexpression of PVT1 restrained or promoted the malignant phenotype and WNT/β-catenin signaling in bladder cancer cells. Meanwhile miR-194-5p was in contrast and miR-194-5p could partially reverse the function of PVT1 in malignant bladder tumor cells. As a microRNA sponge, PVT1 actively promotes the expression of b-cells lymphoma-2-associated transcription factor 1 (BCLAF1) to sponge miR-194-5p and subsequently increases malignant phenotypes of bladder cancer cells. Therefore, it performs a carcinogenic effect and miR-194-5p as the opposite function, and serves as an antioncogene in the bladder carcinomas pathogenesis.

Conclusion: PVT1-miR-194-5p-BCLAF1 axis is involved in the malignant progression and development of bladder carcinomas. Experiments revealed that PVT1 has a significant regulatory effect on bladder cancer (BC) and can be used as a clinical diagnostic marker and a therapeutic molecular marker for patients suffering from BC.

Methods: In urothelial bladder carcinoma specimens and cell lines, the relative expression levels of PVT1 and miR-194-5p were detected by quantitative reverse transcription PCR (RT-qPCR). Through experiments such as loss-function and over-expression, the biological effects of PVT1 and miR-194-5p on the proliferation, migration, apoptosis and tumorigenicity were explored in bladder cancer cells. Co-immunoprecipitation, proteomics experiments, dual luciferase reporter gene analysis, western blot and other methods were adopted to investigate the PVT1 potential mechanism in bladder carcinomas.

Functional mechanisms of miR-192 family in cancer

By growing research on the mechanisms and functions of microRNAs (miRNAs, miRs), the role of these noncoding RNAs gained more attention in healthcare. Due to the remarkable regulatory role of miRNAs, any dysregulation in their expression causes cellular functional impairment. In recent years, it has become increasingly apparent that these small molecules contribute to development, cell differentiation, proliferation, apoptosis, and tumor growth. In many studies, the miR-192 family has been suggested as a potential prognostic and diagnostic biomarker and even as a possible therapeutic target for several cancers. However, the mechanistic effects of the miR-192 family on cancer cells are still controversial. Here, we have reviewed each family member of the miR-192 including miR-192, miR-194, and miR-215, and discussed their mechanistic roles in various cancers.

MiR-194 targets Runx1/Akt pathway to reduce renal fibrosis in mice with unilateral ureteral obstruction

PURPOSE

Chronic kidney disease (CKD) has become a global public health problem and accompanied by renal fibrosis. MiR-194, a tumor suppressor gene, has been previously reported to be associated with the pathogenesis of tissue fibrosis. However, the role of miR-194 in the pathogenesis of renal fibrosis remains unknown.

METHODS

A renal fibrosis model was constructed by unilateral ureteral obstruction (UUO) in male C57BL/6 mice. HE and MASSON stainings were used for histological analysis. The expression level of miR-194 was detected by RT-qPCR. The protein expression was detected by western blotting. The levels of inflammatory cytokines were detected by ELISA. The relationship between miR-194 and Runx1 was further verified by dual luciferase reporter assay.

RESULTS

The results showed that miR-194 level was downregulated in kidney tissue of UUO mice, accompanied by significantly pathological damage and renal fibrosis. MiR-194 mimics significantly reduced pathological damage and alleviated renal fibrosis that caused by UOO, and inhibited the expression levels of α-SMA and collagen I. In addition, miR-194 mimics also reduced the expression level of serum inflammatory factors. Moreover, in vitro analysis indicated that Runx1 was a downstream target gene of miR-194. Furthermore, mechanism analysis indicated that miR-194 reduced mouse renal fibrosis by inhibiting the Runx1/AKT pathway in vivo and in vitro.

CONCLUSION

The present findings suggested that miR-194 targets Runx1/Akt pathway to reduce renal fibrosis in UOO-induced mice. This study provides a novel strategy for the prevention and treatment of renal fibrosis.

DARS-AS1 promotes clear cell renal cell carcinoma by sequestering miR-194-5p to up-regulate DARS

Clear cell renal cell carcinoma (ccRCC), the most frequent subtype of renal cell carcinoma (RCC), is characterized by high relapse rate and mortality. Long non-coding RNAs (lncRNAs) are critical participants during cancer development. LncRNA DARS antisense RNA 1 (DARS-AS1), a newly-found lncRNA, is not specifically reported in ccRCC. However, Gene Expression Profiling Interactive Analysis (GEPIA) and starBase databases revealed the up-regulation of DARS-AS1 in ccRCC. Current study investigated the function and mechanism of DARS-AS1 in ccRCC. Functional assays including colony formation assay, EdU assay, caspase-3 activity detection, flow cytometry analysis and JC-1 assay were implemented to identify the role of DARS-AS1 in ccRCC. As a result, silencing of DARS-AS1 retarded proliferation and facilitated apoptosis in ccRCC cells. Moreover, mainly a cytoplasmic localization of lncRNA DARS-AS1 was verified in ccRCC cells. Then, we demonstrated that DARS-AS1 positively regulated its nearby gene, aspartyl-tRNA synthetase (DARS), by sequestering miR-194-5p. Moreover, DARS was testified as the oncogene in ccRCC and DARS-AS1 worked as a tumor-facilitator in ccRCC through miR-194-5p/DARS signaling. In a summary, this study firstly uncovered that DARS-AS1 boosted DARS expression via absorbing miR-194-5p, therefore contributing to malignancy in ccRCC. Our findings may be helpful for opening new strategies for ccRCC treatment.

Down-regulation of lncRNA NEAT1 regulated by miR-194-5p/DNMT3A facilitates acute myeloid leukemia

OBJECTIVE

miR-194-5p and NEAT1 have been reported to be associated with multiple malignancies, but their roles in acute myeloid leukemia (AML) remains not fully understood.

METHODS

Bone marrow samples were collected for monocyte separation. qRT-PCR assay was performed to investigate the expression patterns of NEAT1 and miR-194-5p in AML. CCK-8, soft agar colony formation, flow cytometry and transwell assays were employed to explore the biological functions of NEAT1 or miR-194-5p. Methylation PCR was performed to monitor the methylation of NEAT1. Luciferase reporter assay was subjected to verify the relationship between miR-194-5p and DNMT3A. Immunofluorescence and western blotting were performed to detect the alterations of protein expression.

RESULTS

NEAT1 and miR-194-5p were both down-regulated in AML. Overexpression of either NEAT1 or miR-194-5p repressed proliferation, induced apoptosis and restrained migration and invasion of AML cells. There was a negative correlation between NEAT1 and DNMT3A in AML. Knockdown of DNMT3A dramatically decreased the methylation of NEAT1. Moreover, DNMT3A was identified as a downstream target of miR-194-5p. Furthermore, down-regulation of DNMT3A rescued the impacts on the malignant phenotypes of NEAT1 inhibition by miR-194-5p inhibitor.

CONCLUSION

Altogether, down-regulation of NEAT1 mediated by miR-194-5p/DNMT3A axis promotes AML progression, which might provide therapeutic targets in AML treatment.

lncRNA MSC-AS1 activates Wnt/β-catenin signaling pathway to modulate cell proliferation and migration in kidney renal clear cell carcinoma via miR-3924/WNT5A

Kidney renal clear cell carcinoma (KIRC) is the most general subtype of renal cell carcinoma, which composes about 1/20 of adult malignancies. The anomaly of long noncoding RNAs (lncRNAs) expression is proved to mediate cancer progression of various types. The function and mediation mechanism of MSC-AS1 has rarely been detected in KIRC before. This study started with the mediation of MSC-AS1 on cell function. In this study, MSC-AS1 was dramatically upregulated in KIRC and correlated with dismal prognosis of KIRC patients. Knockdown of MSC-AS1 would suppress the proliferative and migratory properties of KIRC cells. MSC-AS1 was found to directly downregulate miR-3924 expression while miR-3924 directly downregulated WNT5A expression. Meanwhile, MSC-AS1 could promote the expression of WNT5A, indicating the existence of MSC-AS1/miR-3924/WNT5A. Further assays indicated that MSC-AS1 could enhance Wnt/β-catenin pathway. By means of rescue assays, the mediation of MSC-AS1/miR-3924/WNT5A/β-catenin axis on KIRC cell proliferation, migration and migration was verified. This study revealed that MSC-AS1 regulates KIRC cell proliferation and migration via miR-3924/WNT5A/β-catenin axis. MSC-AS1 might contribute to new strategies for KIRC treatment.

MiR-194-5p inhibited metastasis and EMT of nephroblastoma cells through targeting Crk

Wilms tumor (WT) is the most common solid childhood tumors all over the world. MicroRNAs (miRs) contribute to tumorigenesis of various cancers through targeting gene. The present study investigated the vital role of miR-194-5p and its underlying mechanism in the progression of WT. Immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR) assay indicated downregulation of miR194-5p and upregulation of Crk, in WT tissues compared to adjacent normal tissues. Transfection with miR-194-5p mimics into nephroblastoma cells showed a significant decline in cell migration and invasion, which was detected by Transwell assay. Luciferase assay confirmed that Crk was a direct target gene of miR-194-5p. More important, the mesenchymal to epithelial transition (EMT) biomarkers containing E-cadherin, N-cadherin and Zeb1 were examined by Western blot, and revealed that miR-194-5p mimics decreased the levels of N-cadherin and Zeb1 but increased E-cadherin, which suggested that miR-194-5p inhibited EMT. Crk knockdown could reverse the increased nephroblastoma cell invasion, migration and EMT caused by miR-194-5p inhibitor. Interestingly, qRT-PCR and Western blot analysis showed that overexpression of miR-194-5p deactivated HGF/c-Met/Scr signaling pathway via targeting Crk. In conclusion, miR-194-5p inhibited nephroblastoma cell metastasis and EMT in the progression of WT by targeting Crk. Thus, miR-194-5p might be a potential target in WT particularly for the prevention of metastasis and EMT.

A cluster of long non-coding RNAs exhibit diagnostic and prognostic values in renal cell carcinoma

Kidney cancer ranked in the top 10 for both men and women in the estimated numbers of new cancer cases in the United States in 2018. Targeted therapies have recently been administered to patients with clear cell renal cell carcinoma (ccRCC), but the overall survival of patients at the terminal stage of the disease has not been as good as expected. It is therefore necessary to uncover efficient biomarkers for early diagnosis, and to clarify the molecular mechanisms underlying ccRCC progression and metastasis. Increased evidence has shown that long non-coding RNAs (lncRNAs) play important roles during tumor progression. In this study, 10 candidate lncRNAs with diagnostic and prognostic values in ccRCC were identified: IGFL2-AS1, AC023043.1, AP000439.2, AC124854.1, AL355102.4, TMEM246-AS1, AL133467.3, ZNF582-AS1, LINC01510 and PSMG3-AS1. Enrichment analysis revealed metabolic and functional pathways, which may be closely associated with kidney cancer tumorigenesis. Six representative processes were summarized, namely glycolysis, amino acid metabolism, lipid synthesis, reductive carboxylation, nucleotide metabolism, transmembrane transport and signal transduction. In combination, the present results provided prognostic and diagnostic biomarkers for ccRCC and might pave the way for targeted intervention and molecular therapies in the future.

Investigation of the Clinical Significance and Prognostic Value of the lncRNA ACVR2B-As1 in Liver Cancer

A refined liver cancer staging system and effective prognostic prediction can help clinicians make optimized treatment decisions, which is essential in our fight against cancer and for improving the unsatisfying survival rate of liver cancer globally. The prognosis of liver cancer is not only related to tumor status, it is also affected by the patients' liver functions and the chosen treatment. Currently, several staging systems are being tested. Herein, we analyzed RNA-seq data from the TCGA database and identified a newly annotated lncRNA, ACVR2B-AS1, whose expression is upregulated in liver cancer. Higher ACVR2B-AS1 expression is an independent adverse prognostic factor for overall survival (OS) and relapse-free survival (RFS) in liver cancer patients. Our work suggests that the lncRNA ACVR2B-AS1 could be a candidate biomarker for liver cancer prognosis. Furthermore, ACVR2B-AS1 might serve as a potential therapeutic target, which is a possibility that is worthy of further study.

The role of PEG3 in the occurrence and prognosis of colon cancer

Purpose

Imprinted genes are often identified as key players in the etiology and prognosis of many tumors; however, the role they play in colon cancer remains unclear. Along with the development of big data analysis came the discovery of a wealth of genetic prognostic factors, like microsatellite instability for colon cancer, which need to be taken into consideration when evaluating new biomarkers for the disease.

Methods

We systematically mined public databases to find recurrence free survival (RFS)-related imprinted genes for colon cancer patients on the mRNA level by univariate and multivariate survival analyses. We then investigated the association of methylation status and microRNA expression of the targeted imprinted genes with survival rate of colon cancer patients. Lastly, in a clinical study we used qRT-PCR and immunohistochemistry to quantify mRNA and protein expression of the imprinted genes that related to RFS in our bioinformatics screening, respectively, in 20 tumor tissues compared to paired adjacent tissues.

Results

The results show that paternally expressed gene 3 (PEG3) is the only imprinted gene related to colon cancer patient prognosis on the mRNA level in our datasets, and high mRNA expression of PEG3 is associated with a poor prognosis. Furthermore, the methylation beta value of cg13960339, as well as the expression of 4 microRNAs, negatively correlated with PEG3 mRNA level and were correlated with the prognosis of colon cancer patients. Moreover, the expression of PEG3 mRNA in colon cancer is significantly lower, but PEG3 protein expression is significantly higher compared to that in normal tissues.

Conclusion

PEG3 is likely associated with the progression and prognosis of colon cancer.

miR-135b-5p enhances doxorubicin-sensitivity of breast cancer cells through targeting anterior gradient 2

BACKGROUND

The pro-oncogenic anterior gradient 2 (AGR2) is involved in tumor growth and drug resistance of breast cancer. Mechanisms that regulate expression of AGR2 still need to be elucidated.

METHODS

In this study, expression levels of AGR2 and miR-135b-5p were analyzed in different breast cancer cell lines as well as in clinical breast cancer tissues. The in vitro and in vivo functional effect of AGR2 and miR-135b-5p were also investigated. A luciferase reporter assay was applied to confirm the interaction between miR-135b-5p and AGR2 mRNA.

RESULTS

We identified AGR2 as a target of miR-135b-5p. Expression of AGR2 was up-regulated in doxorubicin-resistant breast cancer cells. AGR2 mediated doxorubicin-sensitivity of breast cancer cells both in vitro and in vivo. miR-135b-5p negatively regulated AGR2-expression of breast cancer cells increasing doxorubicin-sensitivity. However, miR-135b-5p was down-regulated in doxorubicin-resistant breast cancer cells as well as during treatment with doxorubicin, which might be a probable reason for over-expression of AGR2. Up-regulation of miR-135b-5p increased doxorubicin-sensitivity of breast cancer cells in vivo. In addition, levels of AGR2 negatively correlated with levels of miR-135b-5p in clinical breast cancer tissue samples.

CONCLUSION

Our results highlight the potential of miR-135b-5p as a target for treating AGR2-expressing breast cancer with doxorubicin-resistance.