CRNDE Promotes Malignant Progression of Glioma by Attenuating miR-384/PIWIL4/STAT3 Axis

The prognostic model of low-grade glioma based on m6A-associated immune genes and functional study of FBXO4 in the tumor microenvironment

Background

m6A plays a dual role in regulating the expression of oncogenes and tumor suppressor genes, and is crucial in tumorigenesis and progression. The immune system is closely involved in tumorigenesis and development, playing a key role in tumor therapy and resistance. However, research on m6A-related immune markers in low-grade gliomas is still limited and requires further investigation.

Methods

All data was obtained from the Chinese Glioma Genome Atlas database and The Cancer Genome Atlas. The construction of the prognostic model and the online application of the dynamic nomogram relied on univariate Cox analysis, LASSO regression, and multivariate Cox analysis. Two different clustering analyses were performed on all samples, resulting in high, medium, and low expression groups of m6A regulatory and immune genes, followed by an analysis of the correlations between these scores. Finally, the biological role of FBXO4 in glioma cells was determined through quantitative reverse transcription polymerase chain reaction, cell proliferation assays, and cell migration experiments.

Results

The prognostic model for low-grade glioma demonstrated strong performance, with an AUC over 0.9 in the training group. In the internal validation group, AUC values ranged from 0.831 to 0.894, while in the external validation group, the AUC ranged from 0.623 to 0.813. Additionally, the online application of the dynamic nomogram allowed for relatively accurate predictions of LGG patients' survival time. Further analysis revealed that the high-expression groups of m6A regulatory genes and m6A-related immune genes exhibited higher levels of immune cells and stromal cells, lower tumor purity, and poorer survival rates. GSEA enrichment analysis suggested that these findings might be related to the activation of multiple signaling pathways. This may explain the lower survival rates observed in this group. Furthermore, the m6A score was significantly associated with moderate to high expression of immune genes and high expression of m6A regulatory genes, and it showed a positive correlation with most immune cell types. Finally, in vitro experiments confirmed that silencing FBXO4 significantly inhibited proliferation and migration in glioma cell lines, further supporting the biological relevance of our model.

Conclusion

Based on multi-dimensional clustering analysis and experimental validation, the prognostic model developed in this study can effectively assess the prognosis of LGG patients and their relationship with the immune microenvironment. Furthermore, the correlation analysis between m6A scores and the tumor microenvironment provides a foundation for further exploration of the disease's pathophysiology. Additionally, we suggest that FBXO4 may serve as an important biomarker for the diagnosis and prognosis of LGG.

Long Noncoding RNA CRNDE Promotes Gastric Cancer Progression through Targeting miR-136-5p/MIEN1

Background: Long noncoding RNAs (lncRNAs) contribute to the initiation and progression of gastric cancer (GC). This study examined the potential role of lncRNA colorectal neoplasia differentially expressed (CRNDE) in modulating the expression of migration and invasion enhancer 1 (MIEN1) through the suppression of miR-136-5p in GC. Methods: The biological roles of CRNDE, miR-136-5p, and MIEN1 in GC were assessed both in laboratory settings and through the examination of clinical samples. Results: CRNDE was found to be significantly increased in GC tissues, and this upregulation was associated with an unfavorable prognosis of GC patients. In vitro experiments showed that inhibiting cell growth and migration, along with promoting apoptosis in GC cells, could be achieved by either disabling CRNDE or MIEN1, or by increasing the expression of miR-136-5p. MIEN1 is a specific recipient of miR-136-5p, and the anticancer effects of miR-136-5p can be counteracted by the increased expression of MIEN1. Through the examination of clinical specimens, it has been observed that there is a significant positive correlation between the expression of MIEN1 and CRNDE. In contrast, miR-136-5p expression in GC tissues shows a negative correlation. Conclusion: A previously unexplored therapeutic target for GC involves the CRNDE/miR-136-5p/MIEN1 signal transduction cascade.

Immunological processes of enhancers and suppressors of long non-coding RNAs associated with brain tumors and inflammation

Immunological processes, such as inflammation, can both cause tumor suppression and cancer progression. Moreover, deregulated levels of long non-coding RNA (lncRNA) expression in the brain may cause inflammation and lead to the growth of tumors. Like other biological processes, the immune system's role in cancer is complicated, varies, and can help or hurt the cancer's maintenance. According to research, inflammation and brain cancer are correlated via several signaling pathways. A variety of lncRNAs have recently been revealed to influence cancer by modulating inflammatory pathways. As a result, lncRNAs have the potential to influence carcinogenesis, tumor formation, or tumor suppression via an increase or decrease in inflammation functions. Although the study and targeting of lncRNAs have made great progress in the treatment of cancer, there are definitely limitations and challenges. Using new technologies like nanocarriers and cell-penetrating peptides (CPPs) to target treatments without hurting healthy body tissues has shown to be very effective. In this review article, we have collected significantly related lncRNAs and their inhibitory or stimulating roles in inflammation and brain cancer for the first time. However, there are limitations, such as side effects and damage to normal tissues. With the advancement of new targeting technologies, these lncRNAs may be candidates for the specific targeting therapy of brain cancers by limiting inflammation or stimulating the immune system against them in the future.

Expression of lncRNAs in glioma: A lighthouse for patients with glioma

Glioma is the most common malignant tumour in the central nervous system, accounting for approximately 30 % of the primary tumours of this system. The World Health Organization grades for glioma include: Grade I (pilocytic astrocytoma), Grade II (astrocytoma, oligodastoma, etc.), Grade III (anaplastic astrocytoma, anaplastic oligodastoma, etc.) and Grade IV (glioblastoma). With grade increases, the proliferation, invasion and other malignant biological properties of the glioma are enhanced, and the treatment results are less satisfactory. The overall survival of patients with glioblastoma is less than 15 months. Recent research has focused on the roles of long non-coding RNAs, previously regarded as "transcriptional noise", in diseases, leading to a new understanding of these roles. Therefore, we conducted this review to explore the progress of research regarding the expression and mechanism of long non-coding RNAs in glioma.

LncRNA CRNDE Drives the Progression of Hepatocellular Carcinoma by inducing the Immunosuppressive Niche

As a crucial protumorigenic long noncoding RNA, colorectal tumor differential expression (CRNDE) has been confirmed to facilitate the progression of various cancers. However, its role in the tumor microenvironment (TME) of hepatocellular carcinoma (HCC) is still unclear. Here we determined that CRNDE was upregulated in HCC samples and that CRNDE-positive cells were predominantly enriched in malignant tumor cells. In vivo functional assays revealed that CRNDE-induced tumor cells supported HCC progression, recruited abundant granulocyte myeloid-derived suppressor cells (G-MDSCs) and restricted the infiltration of T cells. In terms of mechanisms, CRNDE bound with Toll-like receptor 3 (TLR3) and activated NF-κB signaling to increase the secretion of c-x-c motif chemokine ligand 3 (CXCL3). CRNDE knockdown could significantly suppress the accumulation of G-MDSCs and enhance the infiltration of T cells in the TME of HCC in vivo. Taken together, our study reveals the CRNDE-NF-κB-CXCL3 axis plays a crucial role in driving the immunosuppressive niche to facilitate HCC progression by recruiting G-MDSCs.

circ_0008285 Regulates Glioma Progression via the miR-384/HMGB1 Axis

Background

Recent studies indicate that circular RNAs (circRNAs) have been implicated in the initiation or progression of a wide spectrum of diseases. In the current study, we explored the potential engagement of circ_0008285 in glioma and investigated the downstream regulators.

Methods

The detection of circ_0008285 level in glioma specimens and cell lines was conducted by quantitative real-time polymerase chain reaction. The chi-squared test was employed to evaluate the relationship between the circ_0008285 level and the clinical features of glioma patients. The roles of circ_0008285 on the proliferation and apoptosis of glioma cells were studied by knockdown experiment. Meanwhile, the regulatory relationship of circ_0008285, miR-384, and high mobility group protein B1 (HMGB1) was explored in glioma cells, and we explored the effects of circ_0008285/miR-384/HMGB1 pathway on glioma cells.

Results

In glioma specimens and cell lines, the expression of circ_0008285 was significantly increased, and a high circ_0008285 level was associated with a larger tumor size and more advanced grading in glioma patients. Furthermore, downregulating circ_0008285 suppressed proliferation and triggered apoptosis of glioma cells, which was associated with a cell cycle arrest at the G1/G0 phase. Mechanism studies indicated that circ_0008285 regulated HMGB1 by sponging miR-384. Functional experiments demonstrated that circ_0008285 promoted the malignant phenotype of glioma cells by miR-384/HMGB1 axis.

Conclusion

Our study revealed circ_0008285 as a novel oncogenic factor in glioma through modulating the miR-384/HMGB1 pathway, suggesting that targeting circ_0008285 could serve as a strategy for glioma management.

Deciphering glioma epitranscriptome: focus on RNA modifications

Gliomas are highly malignant tumors accounting for the majority of brain neoplasms. They are characterized by nuclear atypia, high mitotic rate and cellular polymorphism that often contributes to aggressiveness and resistance to standard therapy. They often associate with challenging treatment approaches and poor outcomes. New treatment strategies or regimens to improve the efficacy of glioma treatment require a deeper understanding of glioma occurrence and development as well as elucidation of their molecular biological characteristics. Recent studies have revealed RNA modifications as a key regulatory mechanism involved in tumorigenesis, tumor progression, immune regulation, and response to therapy. The present review discusses research advances on several RNA modifications involved in glioma progression and tumor microenvironment (TME) immunoregulation as well as in the development of adaptive drug resistance, summarizing current progress on major RNA modification targeting strategies.

Insights into the Role of LncRNAs and miRNAs in Glioma Progression and Their Potential as Novel Therapeutic Targets

Accumulating evidence supports that both long non-coding and micro RNAs (lncRNAs and miRNAs) are implicated in glioma tumorigenesis and progression. Poor outcome of gliomas has been linked to late-stage diagnosis and mostly ineffectiveness of conventional treatment due to low knowledge about the early stage of gliomas, which are not possible to observe with conventional diagnostic approaches. The past few years witnessed a revolutionary advance in biotechnology and neuroscience with the understanding of tumor-related molecules, including non-coding RNAs that are involved in the angiogenesis and progression of glioma cells and thus are used as prognostic biomarkers as well as novel therapeutic targets. The emerging research on lncRNAs and miRNAs highlights their crucial role in glioma progression, offering new insights into the disease. These non-coding RNAs hold significant potential as novel therapeutic targets, paving the way for innovative treatment approaches against glioma. This review encompasses a comprehensive discussion about the role of lncRNAs and miRNAs in gene regulation that is responsible for the promotion or the inhibition of glioma progression and collects the existing links between these key cancer-related molecules.

Implications of CRNDE in prognosis, tumor immunity, and therapeutic sensitivity in low grade glioma patients

BACKGROUND

Colorectal tumor differentially expressed (CRNDE) is specifically expressed in human brains and is the most highly expressed lncRNA in gliomas. Nevertheless, its implications in low grade glioma (LGG) are still indistinct. This study presented systematic analyses of CRNDE in LGG biology.

METHODS

We retrospectively retrieved TCGA, CGGC and GSE16011 LGG cohorts. Survival analysis was conducted for evaluating the prognostic significance of CRNDE in LGG. A CRNDE-based nomogram was established, and its predictive performance was verified. Signaling pathways underlying CRNDE were analyzed through ssGSEA and GSEA approaches. The abundance of immune cells and activity of cancer-immunity cycle were estimated with ssGSEA approach. Immune checkpoints, HLAs, chemokines, and immunotherapeutic response indicators (TIDE, and TMB) was quantified. U251 and SW1088 cells were transfected with specific shRNAs of CRNDE, and flow cytometry (apoptosis) and western blot (β-catenin and Wnt5a) assays were conducted.

RESULTS

Up-regulated CRNDE was found in LGG, and was linked to unfavorable clinical outcomes. The CRNDE-based nomogram enabled to accurately predict patients' prognosis. High CRNDE expression was linked to more genomic variations, activity of tumorigenic pathways, tumor immunity (increase in infiltration of immune cells, expression of immune checkpoints, HLAs and chemokines, and cancer-immunity cycle), and therapeutic sensitivity. CRNDE knockdown mitigated malignant phenotypes of LGG cells.

CONCLUSIONS

Our study determined CRNDE as a novel predictor for patient prognosis, tumor immunity and therapeutic response in LGG. Assessment of CRNDE expression is a promising approach for predicting the therapeutic benefits of LGG patients.

LINC01393, a Novel Long Non-Coding RNA, Promotes the Cell Proliferation, Migration and Invasion through MiR-128-3p/NUSAP1 Axis in Glioblastoma

Nucleolar and spindle-associated protein 1 (NUSAP1) is a potential molecular marker and intervention target for glioblastoma (GBM). In this study, we aim to investigate upstream regulatory lncRNAs and miRNAs of NUSAP1 through both experimental and bioinformatic methods. We screened upstream lncRNAs and miRNAs of NUSAP1 through multiple databases based on ceRNA theory. Then, in vitro and in vivo experiments were performed to elucidate the relevant biological significance and regulatory mechanism among them. Finally, the potential downstream mechanism was discussed. LINC01393 and miR-128-3p were screened as upstream regulatory molecules of NUSAP1 by TCGA and ENCORI databases. The negative correlations among them were confirmed in clinical specimens. Biochemical studies revealed that overexpression or knockdown of LINC01393 respectively enhanced or inhibited malignant phenotype of GBM cells. MiR-128-3p inhibitor reversed LINC01393 knockdown-mediated impacts on GBM cells. Then, dual-luciferase reporter assay and RNA immunoprecipitation assay were conducted to validate LINC01393/miR-128-3p/NUSAP1 interactions. In vivo, LINC01393-knockdown decreased tumor growth and improved mice survival, while restoration of NUSAP1 partially reversed these effects. Additionally, enrichment analysis and western blot revealed that the roles of LINC01393 and NUSAP1 in GBM progression were associated with NF-κB activation. Our findings showed that LINC01393 sponged miR-128-3p to upregulate NUSAP1, thereby promoting GBM development and progression via activating NF-κB pathway. This work deepens understanding of GBM mechanisms and provides potential novel therapeutic targets for GBM.

Necroptosis-related lncRNAs: establishment of a gene module and distinction between the cold and hot tumors in glioma

Background

Gliomas are the most common primary tumors of the central nervous system and portend a poor prognosis. The efficacy of emerging and promising immunotherapies varies significantly among individuals. Distinction and transformation of cold and hot tumors may improve the antitumor efficacy of immunotherapy.

Methods and Results

In this study, we constructed a necroptosis-related lncRNA module based on public databases. The association of this module with survival was assessed using the Cox regression, Kaplan-Meier survival analysis, and nomogram, external validation was also conducted in another public database. Furthermore, we performed gene set enrichment analysis (GSEA), immune checkpoint and tumor microenvironment analysis, and in vitro qRT-PCR validation. Finally, we clustered all samples into 2 clusters based on the expression of model lncRNAs and identified cluster 1 as cold tumors with fewer infiltrating T cells.

Conclusions

Identifying cold and hot tumors by necroptosis-related lncRNAs can help available immunotherapeutic strategies to achieve efficacy in the precise treatment of individuals. Prior treatment failure can be overcome by targeting necroptosis-related lncRNAs.

Comprehensive Analysis of the Prognostic Value and Molecular Function of CRNDE in Glioma at Bulk and Single-Cell Levels

Colorectal neoplasia differentially expressed (CRNDE) is an oncogenic long noncoding RNA (lncRNA) overexpressed in diverse malignancies. Here, we comprehensively analyze the prognostic value and molecular function of CRNDE in glioma. Bulk RNA-sequencing data from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA), and single-cell RNA-sequencing data from the Tumor Immune Single-Cell Hub (TISCH) were analyzed. Kaplan-Meier survival analysis was applied to verify the prognostic value of CRNDE. Then, a nomogram based on multivariate Cox regression was established for individualized survival prediction. Subsequently, the expression characteristic and biological function of CRNDE were analyzed at the single-cell level. Lastly, the effects of CRNDE on the proliferation and invasion of glioma cell were explored in vitro. We discovered that CRNDE was a powerful marker for risk stratification of glioma patients. Regardless of the status of IDH and 1p/19q, CRNDE could effectively stratify patients' prognosis. The nomogram that incorporated the CRNDE expression was proved to be a reliable tool for survival prediction. In addition, epithelial-mesenchymal transition may be the most important biological process regulated by CRNDE, which was identified at both the bulk and single-cell levels. Moreover, CRNDE knockdown significantly inhibited the proliferation and invasion of glioma cell. Overall, CRNDE is a vital oncogene and may be a valuable supplement to improve the clinical stratification of glioma.

Particulate Matters Affecting lncRNA Dysregulation and Glioblastoma Invasiveness: In Silico Applications and Current Insights

With a reported rise in global air pollution, more than 50% of the population remains exposed to toxic air pollutants in the form of particulate matters (PMs). PMs, from various sources and of varying sizes, have a significant impact on health as long-time exposure to them has seen a correlation with various health hazards and have also been determined to be carcinogenic. In addition to disrupting known cellular pathways, PMs have also been associated with lncRNA dysregulation-a factor that increases predisposition towards the onset or progression of cancer. lncRNA dysregulation is further seen to mediate glioblastoma multiforme (GBM) progression. The vast array of information regarding cancer types including GBM and its various precursors can easily be obtained via innovative in silico approaches in the form of databases such as GEO and TCGA; however, a need to obtain selective and specific information correlating anthropogenic factors and disease progression-in the case of GBM-can serve as a critical tool to filter down and target specific PMs and lncRNAs responsible for regulating key cancer hallmarks in glioblastoma. The current review article proposes an in silico approach in the form of a database that reviews current updates on correlation of PMs with lncRNA dysregulation leading to GBM progression.

Construction and Verification of a Novel Pyroptosis-Related lncRNA Signature Associated with Immune Landscape in Gliomas

Gliomas are the most common tumor in the central nervous system with limited prognostic markers making it difficult to research progression. Induction of cellular immunogenic death is a promising treatment for glioma. Pyroptosis is one of the recently discovered programmed immuogenic cell death modes which remains unclear in glioma. We obtained glioma datasets from the CGGA and TCGA websites. Pearson correlation analysis was used to find pyroptosis-related lncRNAs. Subsequently, the univariate, LASSO, and multivariate Cox regression were applied to construct a prognostic signature based on pyroptosis-related lncRNAs. Kaplan-Meier plots, ROC curves, and PCA were utilized for testing the prognostic performance of the signature. We conducted the univariate and multivariate Cox regressions to ascertain if the signature worked as an independent factor for predicting overall survival (OS) for individuals with glioma from other characteristics. For evaluating the immune landscape differences between the subgroups, ESTIMATE, CIBERTSORT, and ssGSEA were adopted. Additionally, biological functions and pathways of DEGs were identified by KEGG and GO. We also screened potential drugs and measured sensitivities of chemotherapeutics between the subgroups by CellMiner and pRRophetic package. Finally, shRNA was conducted to knockdown of COX10-AS1 in U87 cells to determine its relationship with pyroptosis. We successfully created an effective pyroptosis-related lncRNA signature that divided individuals into groups of low- and high-risk, and individuals in the high-risk group were with poor prognosis in comparison to the individuals in the other group. A nomogram including clinical factors and risk scores to predict the OS was built. Furthermore, the two groups appeared to have different immune landscapes; the high-risk group showed greater levels of ESTIMATE scores, immune cell infiltration, and immune checkpoints. Additionally, immune-related pathways and functions were shown to be enriched according to KEGG and GO findings. Knockdown of COX10-AS1 inhibited U87 cell growth, upregulated CASP1 and NLRP3, and released more IL1-β and IL-18 than the negative control. In summary, our study developed an lncRNA signature related to pyroptosis for OS prediction of gliomas and demonstrated its relationship with immune infiltration and drug sensitivity.

The lncRNA CRNDE is regulated by E2F6 and sensitizes gastric cancer cells to chemotherapy by inhibiting autophagy

Chemotherapy is an important treatment for gastric cancer (GC), but the primary and secondary drug resistance of tumours to chemotherapy seriously affects its curative effect. In recent years, the relationship between long noncoding RNAs (lncRNAs) and malignant tumours has received increasing attention. Based on accumulating evidence, lncRNAs are involved in the chemoresistance of GC, but the underlying mechanisms remain unclear. In this study, we identified the lncRNA colorectal neoplasia differentially expressed (CRNDE) as an important regulator of autophagy-associated chemoresistance in GC. Mechanistically, overexpression of CRNDE inhibits autophagy and induces apoptosis, thereby sensitizing GC cells to chemotherapy drugs. Moreover, E2F6, a classical transcriptional inhibitor, is confirmed to be upregulated in GC and represses the expression of CRNDE. The E2F6-CRNDE axis is clinically related to chemoresistant GC and poor outcomes in patients with advanced GC. Our findings suggest that the E2F6-CRNDE axis is a viable therapeutic target to protect against chemoresistance in GC.

Regulation of temozolomide resistance via lncRNAs: Clinical and biological properties of lncRNAs in gliomas (Review)

Gliomas are a primary types of intracranial malignancies and are characterized by a poor prognosis due to aggressive recurrence profiles. Temozolomide (TMZ) is an auxiliary alkylating agent that is extensively used in conjunction with surgical resection and forms the mainstay of clinical treatment strategies for gliomas. However, the frequent occurrence of TMZ resistance in clinical practice limits its therapeutic efficacy. Accumulating evidence has demonstrated that long non‑coding RNAs (lncRNAs) can play key and varied roles in glioma progression. lncRNAs have been reported to inhibit glioma progression by targeting various signaling pathways. In addition, the differential expression of lncRNAs has also been found to mediate the resistance of glioma to several chemotherapeutic agents, particularly to TMZ. The present review article therefore summarizes the findings of previous studies in an aim to report the significance and function of lncRNAs in regulating the chemoresistance of gliomas. The present review may provide further insight into the clinical treatment of gliomas.

A novel signature based on necroptosis-related long non-coding RNAs for predicting prognosis of patients with glioma

Necroptosis is closely related to the occurrence and development of tumors, including glioma. A growing number of studies indicate that targeting necroptosis could be an effective treatment strategy against cancer. Long non-coding RNA (lncRNA) is also believed to play a pivotal role in tumor epigenetics. Therefore, it is necessary to identify the functions of necroptosis-related lncRNAs in glioma. In this study, the transcriptome and clinical characteristic data of glioma patients from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) databases were collected, and the differentially expressed necroptosis-related lncRNAs in TCGA that have an impact on overall survival (OS) were screened out to construct risk score (RS) formula, which was verified in CGGA. A nomogram was constructed to predict the prognosis of glioma patients based on clinical characteristics and RS. In addition, Gene Set Enrichment Analysis (GSEA) was used to analyze the main enrichment functions of these necroptosis-related lncRNAs and the immune microenvironment. A total of nine necroptosis-related lncRNAs have been identified to construct the RS formula, and the Kaplan–Meier (K-M) survival analysis showed significantly poorer outcomes in the high RS group in both TCGA and CGGA databases. Moreover, the receiver operating characteristic (ROC) curve shows that our prediction RS model has good predictability. Regarding the analysis of the immune microenvironment, significant differences were observed in immune function and immune checkpoint between the high RS group and the low RS group. In conclusion, we constructed a necroptosis-related lncRNA RS model that can effectively predict the prognosis of glioma patients and provided the theoretical basis and the potential therapeutic targets for immunotherapy against gliomas.

The long non-coding RNA CRNDE promotes osteosarcoma proliferation and migration by sponging miR-136-5p/MRP9 axis

Background

The long-noncoding RNA colorectal neoplasia differentially expressed (CRNDE) gene has been found to be upregulated in several solid tumors. Whether CRNDE affects osteosarcoma (OS) and its underling mechanism remains unknown.

Methods

Tumor tissues and corresponding normal tissues were collected from 45 patients with OS. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was applied to determine lncRNA CRNDE level in the tissues. Participants were divided into a high CRNDE group and a low CRNDE group according to the median value of lncRNA CRNDE expression detected by in situ hybridization (ISH). The differences between high and low expression of lncRNA CRNDE in patients were compared clinically by chi-square test. Kaplan-Meier survival analysis was applied to analyze the relationship between lncRNA CRNDE expression and patient survival. Subsequently, silencing or overexpression of lncRNA CRNDE were performed in MG63 and 143B cell lines, qRT-PCR was applied to verify the expression of lncRNA CRNDE, miR-136-5p, and MRP9; dual-luciferase reporter assay was used to evaluate the targeting relationship between miR-136-5p, lncRNA CRNDE, and Cell Counting Kit-8 (CCK8), wound-healing, and Transwell assays were used to analyze for cell proliferation, migration, and invasion, respectively, and western blot was used to detect expression in cells.

Results

The expression of CRNDE in OS tissues was higher than that in normal tissues. High lncRNA CRNDE expression was significantly associated with clinical stage, lung metastasis, and poor prognosis in OS patients. Additionally, overexpression of lncRNA CRNDE promoted proliferation and migration of OS cells. Bioinformatics analysis showed that lncRNA CRNDE competitively inhibited miR-136-5p through acting as a competitive endogenous RNA (ceRNA). It was also revealed that miR-136-5p is a binding target gene of lncRNA CRNDE and that MRP9 is involved in this process as a downstream target gene of miR-136-5p.

Conclusions

The lncRNA CRNDE promotes the proliferation and migration of OS cells by regulating the miR-136-5p/MRP9 pathway, and lncRNA CRNDE can be a significant marker of OS prognosis.

CRNDE: A valuable long noncoding RNA for diagnosis and therapy of solid and hematological malignancies

Colorectal neoplasia differentially expressed (CRNDE) is an oncogenic long noncoding RNA (lncRNA). Increased CRNDE expression was initially discovered in colorectal cancer and then in a variety of solid tumors and hematological malignancies. CRNDE participates in multiple biological processes, such as cell proliferation, differentiation, migration, and apoptosis. CRNDE has been shown to modulate target gene expression through multiple mechanisms, including transcriptional regulation, post-transcriptional regulation, and competition for microRNA (miRNA) binding. In this review, we summarize the evidence that supports CRNDE in the diagnosis and prognosis predicting of cancers. The functional roles and molecular mechanisms of CRNDE are further described for major types of solid tumors and hematological malignancies. The therapeutic potential of CRNDE as a target for research and development is also discussed.

Long non-coding RNA DDX11-AS1 promotes the proliferation and migration of glioma cells by combining with HNRNPC

Glioma is a malignant tumor of the central nervous system with complex pathogenesis, difficult operation, and a high postoperative recurrence rate. At present, there is still a lack of effective treatment. Long non-coding RNA DDX11 antisense RNA 1 (DDX11-AS1) has been shown to promote tumor development, such as hepatocellular carcinoma, esophageal cancer, etc. However, its molecular mechanism in glioma is poorly understood. In this study, we found that the expression of DDX11-AS1 was elevated in glioma tissues, and patients with high expression of DDX11-AS1 had poor prognosis. DDX11-AS1 was a potential prognostic marker. Functionally, DDX11-AS1 promoted glioma cell proliferation and migration. Mechanistically, DDX11-AS1 interacted with RNA-binding protein heterogeneous nuclear ribonucleoprotein C (HNRNPC) to promote Wnt/β-catenin and AKT pathways and the epithelial-mesenchymal transition process. In summary, our study manifests that the DDX11-AS1/HNRNPC axis may play a vital part in the occurrence and development of glioma, which provides new ideas and therapeutic targets for the diagnosis, treatment, and prognosis of glioma.

Identification of N6-Methyladenosine-Related lncRNAs as a Prognostic Signature in Glioma

N6-methyladenosine (m6A) modification is the most abundant modification in long noncoding RNAs (lncRNAs). Current studies have shown that the abnormal expression of m6A-related genes is closely associated with the tumorigenesis and progression of glioma. However, the role of m6A-related lncRNAs in glioma development is still unclear. Herein, we screened 566 m6A-related lncRNAs in glioma from The Cancer Genome Atlas (TCGA) database. The expression pattern of these lncRNAs could cluster samples into two groups, in which various classical tumor-related functions and the tumor immune microenvironment were significantly different. Subsequently, a nine-factor m6A-related lncRNA prognostic signature (MLPS) was constructed by using a LASSO regression analysis in the training set and was validated in the test set and independent datasets. The AUC values of the MLPS were 0.881, 0.918 and 0.887 for 1-, 3- and 5-year survival in the training set, respectively, and 0.856, 0.916 and 0.909 for 1-, 3-, and 5-year survival in the test set, respectively. Stratification analyses of the MLPS illustrated its prognostic performance in gliomas with different characteristics. Correlation analyses showed that the infiltrations of monocytes and tumor-associated macrophages (TAMs) were significantly relevant to the risk score in the MLPS. Moreover, we detected the expression of four MLPS factors with defined sequences in glioma and normal cells by using RT-PCR. Afterwards, we investigated the functions of LNCTAM34A (one of the MLPS factors) in glioma cells, which have rarely been reported. Via in vitro experiments, LNCTAM34A was demonstrated to promote the proliferation, migration and epithelial-mesenchymal transition (EMT) of glioma cells. Overall, our study revealed the critical role of m6A-related lncRNAs in glioma and elucidated that LNCTAM34A could promote glioma proliferation, migration and EMT.

Current insights on extracellular vesicle-mediated glioblastoma progression: Implications in drug resistance and epithelial-mesenchymal transition

BACKGROUND

Glioblastoma multiforme (GBM) is one of the most fatal tumors of the central nervous system with high rate of disease progression, diagnosis, prognosis and low survival rate. Therapeutic approaches that relied on surgical resection and chemotherapy have been unable to curb the disease progression and subsequently leading to increase in incidences of GBM reoccurrence.

SCOPE OF THE REVIEW

In the recent times, membrane-bound extracellular vesicles (EVs) have been observed as one of the key reasons for the uncontrolled growth of GBM. EVs are shown to have the potential to contribute to the disease progression via mediating drug resistance and epithelial-mesenchymal transition. The GBM-derived EVs (GDEVs) with its cargo contents act as the biological trojan horse and lead to disease progression after being received by the recipient target cells. This review article highlights the biophysical, biochemical properties of EVs, its cargo contents and its potential role in the growth and progression of GBM by altering tumour microenvironment.

MAJOR CONCLUSIONS

EVs are being explored for serving as novel disease biomarkers in a variety of cancer types such as adenocarcinoma, pancreatic cancer, color rectal cancer, gliomas and glioblastomas. Improvement in the EV isolation protocols, polymer-based separation techniques and transcriptomics, have made EVs a key diagnostic marker to unravel the progression and early GBM diagnosis. GDEVs role in tumour progression is under extensive investigations.

GENERAL SIGNIFICANCE

Attempts have been also made to discuss and compare the usage of EVs as potential therapeutic targets versus existing therapies targeting drug resistance and EMT.

LncRNA SNHG14 Sponges miR-206 to Affect Proliferation, Apoptosis, and Metastasis of Hepatocellular Carcinoma Cells by Regulating SOX9

OBJECTIVE

To explore how lncRNA SNHG14 modulates the biological features of hepatocellular carcinoma (HCC) cells by regulating SOX9 via mediating miR-206.

METHODS

HCC tissues were collected to perform the quantitative reverse transcriptase polymerase chain reaction to determine the expressions of SNHG14, miR-206, and SOX9. HCC cell line SMCC7721 was selected for co-transfection by si-SNHG14/miR-206 inhibitor/si-SOX9, followed by the measurement of cell proliferation using Cell Count Kit-8 (CCK-8) assay and clone formation assay. The migration and invasion were evaluated by wound healing test and Transwell assay. The apoptotic rate was determined by flow cytometry. Levels of the apoptosis-related proteins were measured through Western blotting.

RESULTS

SNHG14 and SOX9 were up-regulated in HCC tumor tissues compared with adjacent normal tissues, with decreased miR-206 expression. Moreover, SNHG14 expression was significantly associated with the TNM stage, lymphatic metastasis, and histological differentiation of HCC patients. Besides, inverse correlations between SNHG14 and miR-206, as well as between miR-206 and SOX9, were noted. The dual luciferase reporter gene assay, RIP, and RNA pull-down experiments also revealed the targeting relationship between SNHG14 and miR-206 or between miR-206 and SOX9. Silencing SNHG14 and SOX9 inhibited the proliferation, invasion, and migration of HCC cells, with increased apoptosis, which was all abolished by silencing miR-206.

CONCLUSION

Inhibition of SNHG14 suppresses SOX9 by up-regulating miR-206, to further inhibit the proliferation, migration, and invasion of HCC cells with the promoted apoptosis, which is a novel target for the treatment of HCC.

LncRNA RBPMS-AS1 promotes NRGN transcription to enhance the radiosensitivity of glioblastoma through the microRNA-301a-3p/CAMTA1 axis

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RBPMS-AS1 and CAMTA1 are lowly expressed in GBM patients.

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RBPMS-AS1 and CAMTA1 enhance the radiosensitivity of GBM.

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miR-301a-3p diminishes the radiosensitivity of GBM.

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RBPMS-AS1 enhances CAMTA1 expression in GBM cells through sponging miR-301a-3p.

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CAMTA1 promotes NRGN transcription.

Objective

Glioblastoma (GBM) is the most frequent brain malignancy with high incidence, and long noncoding RNAs (lncRNAs) exerts functions in GBM. In this research, we focused on the capabilities of lncRNA RBPMS-AS1 in radiosensitivity of GBM.

Methods

RBPMS-AS1 and CAMTA1 expression levels were determined in GBM tissues and cells. StarBase v3.0 database was searched for predicting miRNAs that simultaneously bound to RBPMS-AS1 and CAMTA1. pcDNA3.1-RBPMS-AS1, pcDNA3.1-CAMTA1, miR-301a-3p mimic, or pcDNA3.1-RBPMS-AS1/pcDNA3.1-CAMTA1 and miR-301a-3p mimic were transfected into GBM cells to test radiosensitivity, cell proliferation and apoptosis. The interactions of miR-301a-3p with RBPMS-AS1 and CAMTA1, as well as CAMTA1 and NRGN, were confirmed. In vivo imaging technology was utilized to detect tumor growth in orthotopic xenograft tumors, and Ki67 expression was tested in intracranial tumors.

Results

RBPMS-AS1 and CAMTA1 levels were reduced in GBM tissues and cells. miR-301a-3p had a binding site with both RBPMS-AS1 and CAMTA1 and it was the most significantly-upregulated one. Upregulation of RBPMS-AS1 or CAMTA1 enhanced the radiosensitivity and cell apoptosis while suppressing proliferation of GBM cells. Conversely, miR-301a-3p overexpression diminished the radiosensitivity and cell apoptosis while inducing proliferation of GBM cells. Overexpression of RBPMS-AS1 or CAMTA1 reversed the effects of overexpressed miR-301a-3p in GBM cells. Mechanistically, RBPMS-AS1 enhanced CAMTA1 expression in GBM cells through sponging miR-301a-3p, and CAMTA1 promoted NRGN expression. In animal experiments, overexpressed RBPMS-AS1 inhibited tumor growth and the positive expression of Ki67 both before and after radiation therapy.

Conclusion

RBPMS-AS1 promotes NRGN transcription through the miR-301a-3p/CAMTA1 axis and enhances the radiosensitivity of GBM.

SP1-upregulated LBX2-AS1 promotes the progression of glioma by targeting the miR-491-5p/LIF axis

Background: Mounting evidences have shown the importance of lncRNAs in carcinogenesis and cancer progression. LBX2-AS1 is identified as an oncogenic lncRNA that is abnormally expressed in gastric cancer and lung cancer samples. This study aims to explore the potential role of LBX2-AS1 in regulating proliferation and EMT in glioma, and the underlying mechanism. Methods: Relative levels of LBX2-AS1 in glioma samples and cell lines were detected by qRT-PCR and FISH. In vivo and in vitro regulatory effects of LBX2-AS1 on proliferation and EMT were examined in the xenograft glioma model and glioma cells. The interaction between SP1 and LBX2-AS1 was assessed by ChIP. Through bioinformatic analyses, dual-luciferase reporter assay, RIP and Western blot, the regulation of LBX2-AS1 and miR-491-5p on the target gene LIF was identified. Results: LBX2-AS1 was upregulated in glioma samples and cell lines, and its transcription was promoted by binding to the transcription factor SP1. As a lncRNA mainly distributed in the cytoplasm, LBX2-AS1 sponge miR-491-5p to further upregulate LIF. The subsequent activated LIF/STAT3 signaling was responsible for promoting proliferation and EMT in glioma. Conclusion: LBX2-AS1 is upregulated by SP1 in glioma, which promotes the progression of glioma by targeting the miR-491-5p/LIF axis. In view of this, LBX2-AS1 is suggested as a novel diagnostic biomarker and therapeutic target of glioma.

CRNDE/ETS1/GPR17 Facilitates the Proliferation, Migration, and Invasion of Glioma

BACKGROUND

Numerous lncRNAs were found as regulatory factors for occurrence and progression of various tumors, but there is still less research on the role of lncRNAs in malignant progression of glioma.

METHODS

Bioinformatics analysis analyzed differential genes (DEGs) in the TCGA database. MTT, flow cytometry, and Transwell assays were performed to test the proliferation, apoptosis, migration, and invasion of cells. qRT-PCR and western blot were conducted to detect RNA and protein expressions of each gene, respectively. CHIP assay verified the binding relationship between genes. FISH assayed subcellar location of CRNDE, and xenograft in nude mice was performed for in vivo verification.

RESULTS

CRNDE was upregulated in glioma cells, and overexpression of CRNDE facilitated malignant progression of glioma cells. CRNDE regulated occurrence and development of glioma through the CRNDE-ETS1-GPR17 axis. ETS1 was proved to target promoter region of GPR17. Overexpression of CRNDE promoted the binding between ETS1 and the promoter region of GPR17, thus, promoting the transcription of GPR17, while silencing of GPR17 inhibited promotion of CRNDE on proliferation, migration, and invasion of glioma cells.

CONCLUSIONS

These results demonstrated that CRNDE regulated GPR17 expression by binding ETS1, a transcription factor, thereby affecting glioma development. The results also indicated that CRNDE could serve as a possible therapeutic target and prognostic biomarker for glioma.

Regulatory role of miR-129 and miR-384-5p on apoptosis induced by oxygen and glucose deprivation in PC12 cell

This study aimed to establish the role of miR-129 and miR-384-5p in cerebral ischemia-induced apoptosis. Using PC12 cells transfected with miR-129 or miR-384-5p mimics or inhibitors, oxygen glucose deprivation (OGD) conditions were applied for 4 h to simulate transient cerebral ischemia. Apoptotic phenotypes were assessed via lactate dehydrogenase (LDH) assay, MTT cell metabolism assay, and fluorescence-activated cell sorting (FACS). The effect of miR overexpression and inhibition was evaluated by protein and mRNA detection of bcl-2 and caspase-3, critical apoptosis factors. Finally, the direct relationship of miR-129 and bcl-2 and miR-384-5p and caspase-3 was measured by luciferase reporter assay. The overexpression of miR-384-5p and miR-129 deficiency significantly enhanced cell viability, reduced LDH release, and inhibited apoptosis. By contrast, overexpression of miR-129 and miR-384-5p deficiency aggravated hypoxia-induced apoptosis and cell injury. miR-129 overexpression significantly reduced mRNA and protein levels of bcl-2 and miR-129 inhibition significantly increased mRNA and protein levels of bcl-2 in hypoxic cells.miR-384-5p overexpression significantly reduced protein levels of caspase-3 while miR-384-5p deficiency significantly increased protein levels of caspase-3. However, no changes were observed in caspase-3 mRNA in either transfection paradigm. Finally, luciferase reporter assay confirmed caspase-3 to be a direct target of miR-384-5p; however, no binding activity was detected between bcl-2 and miR-129.Transient cerebral ischemia induces differential expression of miR-129 and miR-384-5p which influences apoptosis by regulating apoptotic factors caspase-3 and bcl-2, thereby participating in the pathological mechanism of cerebral ischemia, and becoming potential targets for the treatment of ischemic cerebral injury in the future.

Knockdown of long noncoding RNA colorectal neoplasia differentially expressed inhibits hepatocellular carcinoma progression by mediating the expression of nuclear autoantigenic sperm protein

Long noncoding RNAs (lncRNAs) play critical roles in the tumorigenesis and progression of hepatocellular carcinoma (HCC). As the most common malignant cancer type in humans, HCC poses a great threat to human health. However, the function of lncRNA colorectal neoplasia differentially expressed (CRNDE) in HCC has not been extensively studied. The chief aim of the present study was to reveal the potential role of CRNDE in HCC. Expression levels of CRNDE in HCC tissues and cell lines were detected by reverse transcription‑quantitative (RT‑q) PCR, and Cell Counting kit 8, wound‑healing and Transwell assays were used to evaluate the influences of CRNDE on in vitro cellular proliferation, migration and invasiveness, respectively. The interaction between CRNDE and microRNA (miR)‑29c‑3p was determined by dual‑luciferase reporter assay, and rescue experiments were conducted to evaluate the interactive relationships between CRNDE and miR‑29c‑3p or nuclear autoantigenic sperm protein (NASP). CRNDE was found to be upregulated in HCC tissues and cells, and to be positively associated with the poor prognosis of patients with HCC. Furthermore, CRNDE‑knockdown suppressed cell proliferation, migration and invasion abilities. Bioinformatics and RT‑qPCR analysis indicated miR‑29c‑3p as a potential target of CRNDE. In line with previous reports, as a tumor suppressor, downregulated expression of miR‑29c‑3p was observed in HCC. In addition, the present study revealed that miR‑29c‑3p directly targeted NASP. NASP expression was markedly elevated following transfection with an miR‑29c‑3p inhibitor, while knocking down CRNDE inhibited NASP expression. Moreover, the effects of CRNDE and NASP on HCC cells were reversed by miR‑29c‑3p. Collectively, the results of the present study revealed that CRNDE was upregulated and exerted an oncogenic role in HCC by targeting miR‑29c‑3p, and that the upregulation of CRNDE also promoted NASP expression. These findings indicate a novel role for CRNDE in the progression of HCC.

LncRNA CRNDE exacerbates neuropathic pain in chronic constriction injury-induced(CCI) rats through regulating miR-146a-5p/WNT5A pathway

Neuropathic pain (NP) originating from a dysfunction in the nervous system is often intractable and chronic. Many studies have implicated long noncoding RNAs (lncRNAs) in the physiological and pathological development of NP. The lncRNA colorectal neoplasia differentially expressed gene (CRNDE) has been shown to mediate NP progression. However, further investigations are needed to gain deeper understanding of the specific mechanisms governing CRNDE in NP etiopathology. In this study, we successfully used chronic constrictive injury (CCI)-induced rats to establish an NP model with intrathecal injection, and confirmed the upregulation of CRNDE in CCI-induced rats. Moreover, silencing of CRNDE relieved mechanical allodynia, thermal hyperalgesia, and neuroinflammation in the NP model. Bioinformatics analysis predicted that miR-146a-5p binds to CRNDE. Our findings validated that miR-146a-5p was a target of CRNDE and that the expression of miR-146a-5p was decreased in CCI rats. Furthermore, miR-151A-3p was found to exert a negative regulatory effect on WNT5A. In addition, knockdown of WNT5A alleviated the pain-related behavior and inflammatory response of NP in vivo. Finally, we demonstrated that CRNDE contributed to the progression of CCI-induced NP via competitive binding to miR-146a-5p to upregulate WNT5A. The present study offers novel insights that may be translated into improved therapies for NP.

LncRNA RP1-86C11.7 exacerbates the glioma progression and oncogenicity by hsa-miR-144-3p/TFRC signaling

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High level of TFRC promotes the glioma development.

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Hsa-miR-144-3p inhibitor glioma growth by targeting TFRC.

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LncRNA RP1-86C11.7 exacerbates glioma progression through sponging to hsa-miR-144-3p, resulting in TFRC upregulation.

Glioblastoma (GBM) remains the most common and malignant tumor of the human central nervous system. Increasing evidence has highlighted that tumor cells with high transferrin receptor (TFRC) expression show advantages in growth. Long noncoding RNAs (lncRNAs) are related to glioma progression by mediating microRNAs (miRNAs). However, the underlying mechanism among TFRC, miRNA and lncRNA in GBM is limited. In the current study, we identified a new lncRNA-induced signaling mechanism that regulates the TFRC levels in GBM. The TFRC level was higher in glioma cell lines, and elevated TFRC expression promoted the proliferation and survival of glioma cells. Further study showed that hsa-miR-144a-3p bound to the 3′-UTR of TFRC mRNA and inhibited its expression, preventing the malignant properties of glioma cells, such as proliferation and survival. We also found that the lncRNA RP1-86C11.7 sponges hsa-miR-144-3p to suppress its protective role in glioma. RP1-86C11.7 overexpression in glioma cells elevated TFRC expression, increased the intracellular free iron level, and deteriorated oncogenicity, with a significant reduction in hsa-miR-144-3p. By contrast, silencing RP1-86C11.7 upregulated the hsa-miR-144-3p level, resulting in decreased TFRC expression and repressed glioma progression. However, the effect of silencing RP1-86C11.7 was reversed with simultaneous hsa-miR-144-3p inhibitor treatment: the TFRC level, intracellular iron level and proliferation in glioma cells increased. Mechanistically, our data indicated that RP1-86C11.7 exacerbates the malignant behavior of glioma through the hsa-miR-144-3p/TFRC axis. RP1-86C11.7 may be a potential biomarker or target to treat glioma in the future.

Knockdown lncRNA CRNDE enhances temozolomide chemosensitivity by regulating autophagy in glioblastoma

Background

The regulatory roles of long non-coding RNA (lncRNA) CRNDE in temozolomide (TMZ) chemoresistance to glioblastoma multiforme (GBM) are still poorly understood. Therefore, the function, characteristics, and possible mechanism of CRNDE in TMZ-induced chemoresistance to GBM were explored.

Methods

Firstly, the expression level of CRNDE in 58 cases of glioma tissue specimens and 30 cases of normal brain tissues were tested by qRT-PCR. Meanwhile, the correlation between CRNDE expression level, the clinicopathological characteristics, and survival time of patients with glioma were analyzed. Then, the CRNDE expression in various glioma cell lines was detected, and CRNDE knockdown cell models were constructed. Subsequently, to explore the effect of CRNDE on chemosensitivity to TMZ, cell viability was detected by the CCK-8 assay and IC₅₀ values, and cell proliferation was detected by cell clone assay and EdU assay, as well as cell survival was detected by apoptosis with flow cytometry under TMZ treatment. Further, the expression of drug-resistance protein ABCG2, autophagy related proteins, and PI3K/Akt/mTOR pathway were measured by western blot or qRT-PCR in TMZ-treated glioma cells. Finally, the mouse tumor xenograft model was established and the tumor volume and weight were measured, and ABCG2 expression was conducted by immunohistochemistry assay.

Results

The integrated results demonstrated lncRNA CRNDE was a poor prognosis factor for GBM patient, which was upregulated in patients who were resistant to TMZ, and closely associated with chemotherapeutic response status to TMZ treatment. Further, functional assays revealed that knockdown of CRNDE could notably reduce glioma cell viability and proliferation, and elevate cell apoptosis to enhance the chemosensitivity to TMZ in vitro and in vivo. Mechanistically, the depression of CRNDE could diminish the expression of LC3 II/I, Beclin1 and Atg5 and increase the p62 expression level to inhibit autophagy due to the activation of PI3K/Akt/mTOR pathway as well as highly correlated with ABCG2 expression.

Conclusions

Overall, the study provided that lncRNA CRNDE is a reliable clinical predictor of outcome and prognosis and a potential biomarker for predicting TMZ treatment response in GBM by modulating the autophagy through PI3K/Akt/mTOR pathway and ABCG2 expression which may be a novel therapeutic target for regulating TMZ sensitivity to GBM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02153-x.

Noncoding RNAs involved in the STAT3 pathway in glioma

Glioma is the most common malignant primary brain tumour in adults. Despite improvements in neurosurgery and radiotherapy, the prognosis of glioma patients remains poor. One of the main limitations is that there are no proper clinical therapeutic targets for glioma. Therefore, it is crucial to find one or more effective targets. Signal transducer and activator of transcription 3 (STAT3) is a member of the STAT family of genes. Abnormal expression of STAT3 is involved in the process of cell proliferation, migration, invasion, immunosuppression, angiogenesis, dryness maintenance, and resistance to radiotherapy and chemotherapy in glioma. Therefore, STAT3 has been considered an ideal therapeutic target in glioma. Noncoding RNAs (ncRNAs) are a group of genes with limited or no protein-coding capacity that can regulate gene expression at the epigenetic, transcriptional and posttranscriptional level. In this review, we summarized the ncRNAs that are correlated with the ectopic expression of STAT3 in glioma.

CRNDE enhances the expression of MCM5 and proliferation in acute myeloid leukemia KG-1a cells by sponging miR-136-5p

The long-noncoding RNA colorectal neoplasia differentially expressed (CRNDE) gene has been considered to be crucial in tumor malignancy. Although CRNDE is highly expressed in acute myeloid leukemia (AML), its mechanism of action remains unknown. In this study, GEPIA and qRT-PCR were performed to confirm the expression of CRNDE in AML samples and cell lines, respectively. CRNDE shRNA vectors were transfected to explore the biological functions of CRNDE. The cell proliferation was assessed by the CCK8 assay, while apoptosis and cell cycle distribution were measured by flow cytometry and Western blotting. The results showed that CRNDE was overexpressed in both AML samples and cell lines. CRNDE silencing inhibited proliferation and increased apoptotic rate and cell cycle arrest of KG-1a cells. The luciferase reporter assay coupled with RIP assay revealed that CRNDE act as a ceRNA. Rescue assays demonstrated that the effects of CRNDE silencing could be reversed by miR-136-5p inhibitors. In conclusion, our results expound that the CRNDE/miR-136-5p/MCM5 axis modulates cell progression and provide a new regulatory network of CRNDE in KG-1a cells.

Vitamin D affects the Warburg effect and stemness maintenance of non-small-cell lung cancer cells by regulating PI3K/AKT/mTOR signaling pathway

BACKGROUND

Non-small-cell lung cancer (NSCLC) is the most prevalent form of lung cancer, accounting for approximately 85% of all lung cancer cases and resulting in high morbidity and mortality. Previous studies have demonstrated that 1,25-dihydroxy-vitamin-D3 (vitamin D) exhibited anti-cancer activity against breast and prostate cancer.

OBJECTIVES

The aim of the current study is to investigate the effect of vitamin D on NSCLC and its underlying mechanism.

METHODS

The effects of vitamin D on stemness maintenance and the Warburg effect in NSCLC cells were investigated both in vitro and in vivo.

RESULTS & DISCUSSION

In vitro experiments revealed that vitamin D inhibited glycolysis and stemness maintenance in A549 and NCI-H1975 cells. Both in vitro and in vivo experiments indicated that vitamin D attenuated the expression of metabolism-related enzymes associated with the Warburg effect (GLUT1, LDHA, HK2, and PKM2). In addition, vitamin D down-regulated the expression of stemness-related genes (Oct-4, SOX-2, and Nanog) and the expression of PI3K, AKT, and mTOR.

CONCLUSION

Overall, these findings suggest that vitamin D suppresses the Warburg effect and stemness maintenance in NSCLC cells via the inactivation of PI3K/AKT/mTOR signaling, thereby inhibiting the progression of NSCLC. The current study indicates that vitamin D is a potential candidate in therapeutic strategies against NSCLC.

Role of mammalian long non-coding RNAs in normal and neuro oncological disorders

Long non-coding RNAs (lncRNAs) are expressed at lower levels than protein-coding genes but have a crucial role in gene regulation. LncRNA is distinct, they are being transcribed using RNA polymerase II, and their functionality depends on subcellular localization. Depending on their niche, they specifically interact with DNA, RNA, and proteins and modify chromatin function, regulate transcription at various stages, forms nuclear condensation bodies and nucleolar organization. lncRNAs may also change the stability and translation of cytoplasmic mRNAs and hamper signaling pathways. Thus, lncRNAs affect the physio-pathological states and lead to the development of various disorders, immune responses, and cancer. To date, ~40% of lncRNAs have been reported in the nervous system (NS) and are involved in the early development/differentiation of the NS to synaptogenesis. LncRNA expression patterns in the most common adult and pediatric tumor suggest them as potential biomarkers and provide a rationale for targeting them pharmaceutically. Here, we discuss the mechanisms of lncRNA synthesis, localization, and functions in transcriptional, post-transcriptional, and other forms of gene regulation, methods of lncRNA identification, and their potential therapeutic applications in neuro oncological disorders as explained by molecular mechanisms in other malignant disorders.

Long Non-Coding RNAs in Diagnosis, Treatment, Prognosis, and Progression of Glioma: A State-of-the-Art Review

Glioma is the most common malignant central nervous system tumor with significant mortality and morbidity. Despite considerable advances, the exact molecular pathways involved in tumor progression are not fully elucidated, and patients commonly face a poor prognosis. Long non-coding RNAs (lncRNAs) have recently drawn extra attention for their potential roles in different types of cancer as well as non-malignant diseases. More than 200 lncRNAs have been reported to be associated with glioma. We aimed to assess the roles of the most investigated lncRNAs in different stages of tumor progression and the mediating molecular pathways in addition to their clinical applications. lncRNAs are involved in different stages of tumor formation, invasion, and progression, including regulating the cell cycle, apoptosis, autophagy, epithelial-to-mesenchymal transition, tumor stemness, angiogenesis, the integrity of the blood-tumor-brain barrier, tumor metabolism, and immunological responses. The well-known oncogenic lncRNAs, which are upregulated in glioma, are H19, HOTAIR, PVT1, UCA1, XIST, CRNDE, FOXD2-AS1, ANRIL, HOXA11-AS, TP73-AS1, and DANCR. On the other hand, MEG3, GAS5, CCASC2, and TUSC7 are tumor suppressor lncRNAs, which are downregulated. While most studies reported oncogenic effects for MALAT1, TUG1, and NEAT1, there are some controversies regarding these lncRNAs. Expression levels of lncRNAs can be associated with tumor grade, survival, treatment response (chemotherapy drugs or radiotherapy), and overall prognosis. Moreover, circulatory levels of lncRNAs, such as MALAT1, H19, HOTAIR, NEAT1, TUG1, GAS5, LINK-A, and TUSC7, can provide non-invasive diagnostic and prognostic tools. Modulation of expression of lncRNAs using antisense oligonucleotides can lead to novel therapeutics. Notably, a profound understanding of the underlying molecular pathways involved in the function of lncRNAs is required to develop novel therapeutic targets. More investigations with large sample sizes and increased focus on in-vivo models are required to expand our understanding of the potential roles and application of lncRNAs in glioma.

Large-Scale Transcriptomics-Driven Approach Revealed Overexpression of CRNDE as a Poor Survival Prognosis Biomarker in Glioblastoma

Glioblastoma is the most common and malignant brain malignancy worldwide, with a 10-year survival of only 0.7%. Aggressive multimodal treatment is not enough to increase life expectancy and provide good quality of life for glioblastoma patients. In addition, despite decades of research, there are no established biomarkers for early disease diagnosis and monitoring of patient response to treatment. High throughput sequencing technologies allow for the identification of unique molecules from large clinically annotated datasets. Thus, the aim of our study was to identify significant molecular changes between short- and long-term glioblastoma survivors by transcriptome RNA sequencing profiling, followed by differential pathway-activation-level analysis. We used data from the publicly available repositories The Cancer Genome Atlas (TCGA; number of annotated cases = 135) and Chinese Glioma Genome Atlas (CGGA; number of annotated cases = 218), and experimental clinically annotated glioblastoma tissue samples from the Institute of Pathology, Faculty of Medicine in Ljubljana corresponding to 2-58 months overall survival (n = 16). We found one differential gene for long noncoding RNA CRNDE whose overexpression showed correlation to poor patient OS. Moreover, we identified overlapping sets of congruently regulated differential genes involved in cell growth, division, and migration, structure and dynamics of extracellular matrix, DNA methylation, and regulation through noncoding RNAs. Gene ontology analysis can provide additional information about the function of protein- and nonprotein-coding genes of interest and the processes in which they are involved. In the future, this can shape the design of more targeted therapeutic approaches.

The Effect and Mechanism of LINC00663 on the Biological Behavior of Glioma

Glioma is the most frequent primary malignant brain tumor, which is characterized by high incidence and mortality, with a poor prognosis. Numerous studies have revealed the abnormal expression of long non-coding RNAs in gliomas. This study explored the effects and potential mechanism of LINC00663 in glioma. The LINC00663 levels and their prognostic values were analyzed from the GEO databases using bioinformatics. Also, LINC00663 expression in tissue samples and cell lines was measured using qRT-PCR. The roles of LINC00663 in glioma were confirmed using CCK8, EdU assay as well as Transwell tests. Moreover, the influences of LINC00663 on the AKT/mTOR signal cascades were detected using western blotting assay. LINC00663 expression was higher in both glioma tissues and cell lines than that in the normal brain tissues and human astrocytes. High expression of LINC00663 led to the low overall survival rate of patients with glioma. LINC00663 knockdown notably restrained cell proliferation, migration, and invasion abilities by decreasing the activation of AKT and mTOR. This study indicated that LINC00663 might have a cancer-promoting role in accelerating glioma development and progression through regulating AKT/mTOR pathway.

CRNDE-h transcript/miR-136-5p axis regulates interleukin enhancer binding factor 2 expression to promote hepatocellular carcinoma cell proliferation

AIMS

Hepatocellular carcinoma (HCC) is a primary malignancy of the hepatocyte. Interleukin enhancer binding factor 2 (ILF2) plays a role in the development of HCC. However, the regulatory mechanisms of ILF2 expression in HCC remain unclear. In this study, we aimed to identify ILF2-targeting microRNAs (miRNAs) and to explore how they affect ILF2 expression in HCC.

MAIN METHODS

The tissue specimens were collected from 25 HCC patients. The underlying regulatory mechanism of ILF2 expression in HCC progression was determined using luciferase reporter assay, quantitative real-time PCR, Western blotting, and BrdU incorporation assay.

KEY FINDINGS

Of predicted miRNA candidates (miR-122-5p, miR-425-5p, miR-136-5p, miR-7-5p, miR-421 and miR-543), a statistically significant inverse correlation by linear correlation analysis was observed between miR-136-5p and ILF2 mRNA expressions in patients with HCC (r = -0.627, P < 0.001). Further analysis demonstrated that ILF2 was directly regulated by miR-136-5p. In addition, we showed that long noncoding RNA colorectal neoplasia differentially expressed-h (lncRNA CRNDE-h) transcript expression was significantly up-regulated in HCC, and a miR-136-5p binding site was newly found in the lncRNA CRNDE-h transcript sequence using IntaRNA tool. In terms of mechanism, highly-expressed lncRNA CRNDE-h transcript can sponge miR-136-5p, thereby preventing it from interacting with target ILF2 mRNA while promoting the proliferation of HCC cells.

SIGNIFICANCE

The lncRNA CRNDE-h/miR-136-5p/ILF2 axis plays a significant regulatory role in HCC progression, which may partly explain the pathogenic mechanisms of HCC and may provide promising potential targets for the diagnosis, treatment, and prognosis of HCC.

Long non-coding RNAs mediate cerebral vascular pathologies after CNS injuries

Central nervous system (CNS) injuries are one of the leading causes of morbidity and mortality worldwide, accompanied with high medical costs and a decreased quality of life. Brain vascular disorders are involved in the pathological processes of CNS injuries and might play key roles for their recovery and prognosis. Recently, increasing evidence has shown that long non-coding RNAs (lncRNAs), which comprise a very heterogeneous group of non-protein-coding RNAs greater than 200 nucleotides, have emerged as functional mediators in the regulation of vascular homeostasis under pathophysiological conditions. Remarkably, lncRNAs can regulate gene transcription and translation, thus interfering with gene expression and signaling pathways by different mechanisms. Hence, a deeper insight into the function and regulatory mechanisms of lncRNAs following CNS injury, especially cerebrovascular-related lncRNAs, could help in establishing potential therapeutic strategies to improve or inhibit neurological disorders. In this review, we highlight recent advancements in understanding of the role of lncRNAs and their application in mediating cerebrovascular pathologies after CNS injury.

Circular RNA circHECTD1 prevents Diosbulbin-B-sensitivity via miR-137/PBX3 axis in gastric cancer

Backgrounds

Gastric cancer (GC) is general disease in human digestive system with malignancy. Emerging findings indicated that hsa_circ_0031452 (circHECTD1) was strictly associated with carcinogenesis. Nevertheless, the role of circHECTD1 in drug-resistance still needed to be explained.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to examine the expression profiles of circHECTD1, microRNA (miR)-137, and pre-leukemia transcription factor 3 (PBX3). The function of circHECTD1 in tumorigenesis was evaluated via xenograft tumor model. The IC₅₀ of Diosbulbin-B (DB) was detected using Cell Counting Kit-8 (CCK8). Cell-cycle and apoptosis were reckoned by flow cytometry. Besides, western blot was administrated to reckon the levels of PBX3 and cell apoptotic indicators. Moreover, the interrelation between miR-137 and circHECTD1 or PBX3 was expounded by dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull down assays.

Results

We uncovered that circHECTD1 was ectopically up-regulated in GC tissues and cells. CircHECTD1 deficiency sensitized DB-treatment in DB-evoked AGS and HGC-27 cells. In vivo assay, circHECTD1 silencing led to the tumor reduction. Also, circHECTD1 served as miR-137 sponge in a sequence-complementary manner. Furthermore, transfection of miR-137 inhibitor markedly eliminated circHECTD1 absence-mediated promotion of DB-sensitivity in GC cells. Moreover, PBX3, a target of miR-137, play a DB-resistant role in GC cells. Fascinatingly, the deletion of PBX3 reversed the impact of miR-137 repression and circHECTD1 knockdown on DB-sensitivity in vitro.

Conclusions

CircHECTD1 served as an oncogene by a novel miR-137/PBX3 axis, which might supply an underlying biomarker for the diagnosis and prognosis of GC management.

Long non-coding RNAs in brain tumors: roles and potential as therapeutic targets

Brain tumors are associated with adverse outcomes despite improvements in radiation therapy, chemotherapy, and photodynamic therapy. However, treatment approaches are evolving, and new biological phenomena are being explored to identify the appropriate treatment of brain tumors. Long non-coding RNAs (lncRNAs), a type of non-coding RNA longer than 200 nucleotides, regulate gene expression at the transcriptional, post-transcriptional, and epigenetic levels and are involved in a variety of biological functions. Recent studies on lncRNAs have revealed their aberrant expression in various cancers, with distinct expression patterns associated with their instrumental roles in cancer. Abnormal expression of lncRNAs has also been identified in brain tumors. Here, we review the potential roles of lncRNAs and their biological functions in the context of brain tumors. We also summarize the current understanding of the molecular mechanisms and signaling pathways related to lncRNAs that may guide clinical trials for brain tumor therapy.

LINC02308 promotes the progression of glioma through activating mTOR/AKT-signaling pathway by targeting miR-30e-3p/TM4SF1 axis

BACKGROUND

Glioma is a common brain malignancy, and the purpose of this study is to investigate the function of LINC02308 in glioma.

METHODS

The differentially expressed lncRNAs were screened by microarray. The expression of LINC02308 in glioma tissues and cells was evaluated. The interaction among LINC02308, miR-30e-3p, and TM4SF1 was determined. Cell proliferation and apoptosis were evaluated. The expression of mTOR/AKT-signaling and apoptosis-related markers was detected by Western blot. A xenograft tumor mouse model was constructed to investigate the roles of LINC02308.

RESULTS

LINC02308 was significantly overexpressed in glioma, and a high LINC02308 level was correlated with a poor prognosis. LINC02308 silencing markedly inhibited proliferation and reduced apoptosis of glioma cells and also suppressed tumor growth in the xenograft tumor mouse model. Finally, we demonstrated that LINC02308 played its oncogenic role through binding to miR-30e-3p so as to relieve miR-30e-3p-induced suppression of TM4SF1.

CONCLUSIONS

LINC02308 promoted glioma tumorigenesis as a sponge of miR-30e-3p to upregulate TM4SF1 and activate AKT/mTOR pathway. Graphical Abstract Hypothesis diagram illustrates the function and mechanism of LINC02308 in glioma. A schematic representation of the functional mechanism of LINC02308 in glioma.

Propofol prevents the aggressive progression of oral squamous cell carcinoma via regulating circ_0005623/miR-195-5p/HOXB7 axis

Oral squamous cell carcinoma (OSCC) is a general oral disease with high mortality. This study aimed to investigate the effects and underlying mechanism of propofol in OSCC. Propofol treatment inhibited cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT), but promoted apoptosis and induced cell cycle arrest in OSCC cells. miR-195-5p was a target of circ_0005623 and directly targeted to HOXB7. Circ_0005623 and HOXB7 were upregulated, while miR-195-5p was downregulated in OSCC tissues and cells. Overexpression of circ_0005623 partly reversed the effects of propofol on cell proliferation, migration invasion, EMT, cell cycle progression, and apoptosis in SCC-9 and CAL-27 cells. Meanwhile, further investigation uncovered that circ_0005623 could act as a sponge for miR-195-5p to regulate HOXB7 expression, thereby mediating the suppression effects of propofol on OSCC cells. In vivo assay suggested that overexpression of circ_0005623 promoted tumor growth, which was inhibited by propofol treatment. Taken together, propofol regulated aggressive progression of OSCC via the circ_0005623/miR-195-5p/HOXB7 axis, providing the new train of thoughts for diagnosis and therapy of human OSCC.

LncRNAs associated with glioblastoma: From transcriptional noise to novel regulators with a promising role in therapeutics

Glioblastoma multiforme (GBM) is the most widespread and aggressive subtype of glioma in adult patients. Numerous long non-coding RNAs (lncRNAs) are deregulated or differentially expressed in GBM. These lncRNAs possess unique regulatory functions in GBM cells, ranging from high invasion/migration to recurrence. This review outlines the present status of specific involvement of lncRNAs in GBM pathogenesis, with a focus on their association with key molecular and cellular regulatory mechanisms. Also, we highlighted the potential of different novel RNA-based strategies that may be beneficial for therapeutic purposes.

Knockdown of LncRNA CRNDE suppresses proliferation and P-glycoprotein-mediated multidrug resistance in acute myelocytic leukemia through the Wnt/β-catenin pathway

Mechanisms involved in non-coding RNAs have been implicated in multidrug resistance (MDR) of acute myeloid leukemia (AML). Long non-coding RNA (lncRNAs) colorectal neoplasia differentially expressed (CRNDE) is reported to be involved in the malignant progression in AML. The purpose of the present study is to explore the roles and potential molecular mechanism of CRNDE in the MDR in AML. In our study, we confirmed that the expression of CRNDE was significantly up-regulated in patients with AML, especially in AML patients after adriamycin (ADR)-based chemotherapy. Spearman correlation analysis showed a positive correlation between the levels of CRNDE and MDR1 in AML patients after ADR-based chemotherapy. Moreover, CRNDE was up-regulated in AML cells, especially in ADR-resistant AML cells. Multidrug resistance protein 1 (MDR1)/p-glycoprotein (P-gp) levels were significantly increased in ADR-resistant AML cells, compared with parental AML cells. CRNDE down-regulation inhibited cell proliferation, promoted apoptosis, reduced Ki67 expression and enhanced cleaved caspase-3 expression in AML and ADR-resistant AML cells. In addition, CRNDE knockdown led to down-regulation of P-gp/MDR1, β-catenin, c-Myc and cyclinD1 expression, and enhanced the drug sensitivity to ADR in ADR-resistant AML cells. In conclusion, knockdown of CRNDE suppresses proliferation and P-gp-mediated MDR in ADR-resistant AML cells via inhibiting the Wnt/β-catenin pathway, suggesting that repression of CRNDE might be a therapeutic target to reverse MDR of ADR-resistant AML cells.

Noncoding RNAs in Glioblastoma: Emerging Biological Concepts and Potential Therapeutic Implications

Simple Summary

Since the completion of the Human Genome Project, noncoding RNAs (ncRNAs) have emerged as an important class of genetic regulators. Several classes of ncRNAs, which include microRNAs (miRNAs), long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and piwi-interacting RNAs (piRNAs), have been shown to play important roles in controlling developmental and disease processes. In this article, we discuss the potential roles of ncRNAs in regulating glioblastoma (GBM) formation and progression as well as potential strategies to exploit the diagnostic and therapeutic potential of ncRNAs in GBM.

Abstract

Noncoding RNAs (ncRNAs) have emerged as a novel class of genomic regulators, ushering in a new era in molecular biology. With the advent of advanced genetic sequencing technology, several different classes of ncRNAs have been uncovered, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and piwi-interacting RNAs (piRNAs), which have been linked to many important developmental and disease processes and are being pursued as clinical and therapeutic targets. Molecular phenotyping studies of glioblastoma (GBM), the most common and lethal cancer of the adult brain, revealed that several ncRNAs are frequently dysregulated in its pathogenesis. Additionally, ncRNAs regulate many important aspects of glioma biology including tumour cell proliferation, migration, invasion, apoptosis, angiogenesis, and self-renewal. Here, we present an overview of the biogenesis of the different classes of ncRNAs, discuss their biological roles, as well as their relevance to gliomagenesis. We conclude by discussing potential approaches to therapeutically target the ncRNAs in clinic.

Long Non-Coding RNAs in Multidrug Resistance of Glioblastoma

Glioblastoma, also known as glioblastoma multiforme, is the most aggressive brain tumor in adults. Despite the huge advance in developing novel therapeutic strategies for patients with glioblastoma, the appearance of multidrug resistance (MDR) against the common chemotherapeutic agents, including temozolomide, is considered as one of the important causes for the failure of glioblastoma treatment. On the other hand, recent studies have demonstrated the critical roles of long non-coding RNAs (lncRNAs), particularly in the development of MDR in glioblastoma. Therefore, this article aimed to review lncRNA's contribution to the regulation of MDR and elucidate the underlying mechanisms in glioblastoma, which will open up new lines of inquiry in the treatment of glioblastoma.