LncRNA RPSAP52 Upregulates TGF-β1 to Increase Cancer Cell Stemness and Predict Postoperative Survival in Glioblastoma

Shedding light on function of long non-coding RNAs (lncRNAs) in glioblastoma

The brain tumors and especially glioblastoma, are affecting life of many people worldwide and due to their high mortality and morbidity, their treatment is of importance and has gained attention in recent years. The abnormal expression of genes is commonly observed in GBM and long non-coding RNAs (lncRNAs) have demonstrated dysregulation in this tumor. LncRNAs have length more than 200 nucleotides and they have been located in cytoplasm and nucleus. The current review focuses on the role of lncRNAs in GBM. There two types of lncRNAs in GBM including tumor-promoting and tumor-suppressor lncRNAs and overexpression of oncogenic lncRNAs increases progression of GBM. LncRNAs can regulate proliferation, cell cycle arrest and metastasis of GBM cells. Wnt, STAT3 and EZH2 are among the molecular pathways affected by lncRNAs in GBM and for regulating metastasis of GBM cells, these RNA molecules mainly affect EMT mechanism. LncRNAs are involved in drug resistance and can induce resistance of GBM cells to temozolomide chemotherapy. Furthermore, lncRNAs stimulate radio-resistance in GBM cells. LncRNAs increase PD-1 expression to mediate immune evasion. LncRNAs can be considered as diagnostic and prognostic tools in GBM and researchers have developed signature from lncRNAs in GBM.

lncRNA Biomarkers of Glioblastoma Multiforme

Long noncoding RNAs (lncRNAs) are RNA molecules of 200 nucleotides or more in length that are not translated into proteins. Their expression is tissue-specific, with the vast majority involved in the regulation of cellular processes and functions. Many human diseases, including cancer, have been shown to be associated with deregulated lncRNAs, rendering them potential therapeutic targets and biomarkers for differential diagnosis. The expression of lncRNAs in the nervous system varies in different cell types, implicated in mechanisms of neurons and glia, with effects on the development and functioning of the brain. Reports have also shown a link between changes in lncRNA molecules and the etiopathogenesis of brain neoplasia, including glioblastoma multiforme (GBM). GBM is an aggressive variant of brain cancer with an unfavourable prognosis and a median survival of 14-16 months. It is considered a brain-specific disease with the highly invasive malignant cells spreading throughout the neural tissue, impeding the complete resection, and leading to post-surgery recurrences, which are the prime cause of mortality. The early diagnosis of GBM could improve the treatment and extend survival, with the lncRNA profiling of biological fluids promising the detection of neoplastic changes at their initial stages and more effective therapeutic interventions. This review presents a systematic overview of GBM-associated deregulation of lncRNAs with a focus on lncRNA fingerprints in patients' blood.

Role of Non-Coding RNAs in TGF-β Signalling in Glioma

Brain tumours and Gliomas, in particular, are among the primary causes of cancer mortality worldwide. Glioma diagnosis and therapy have not significantly improved despite decades of efforts. Autocrine TGF-β signalling promotes glioma proliferation, invasion, epithelial-to-mesenchymal transition (EMT), and drug resistance. Non-coding RNAs such as miRNA, lncRNA, and circRNAs have emerged as critical transcriptional and post-transcriptional regulators of TGF-β pathway components in glioma. Here, we summarize the complex regulatory network among regulatory ncRNAs and TGF-β pathway during Glioma pathogenesis and discuss their role as potential therapeutic targets for Gliomas.

Biological role and diagnostic utility of ribosomal protein L23a pseudogene 53 in cutaneous melanoma

Background

Skin melanoma is one of the deadliest types of skin cancer and develops from melanocytes. The genetic aberrations in protein-coding genes are well characterized, but little is known about changes in non-coding RNAs (ncRNAs) such as pseudogenes. Ribosomal protein pseudogenes (RPPs) have been described as the largest group of pseudogenes which are dispersed in the human genome.

Materials and methids

We looked deeply at the role of one of them, ribosomal protein L23a pseudogene 53 (RPL23AP53), and its potential diagnostic use. The expression level of RPL23AP53 was profiled in melanoma cell lines using real time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and analyzed based on the Cancer Genome Atlas (TCGA) data depending on BRAF status and clinicopathological parameters. Cellular phenotype, which was associated with RPL23AP53 levels, was described based on the REACTOME pathway browser, Gene Set Enrichment Analysis (GSEA) analysis as well as Immune and ESTIMATE Scores.

Results

We indicted in vitro changes in RPL23AP53 level depending on a cell line, and based on in silico analysis of TCGA samples demonstrated significant differences in RPL23AP53 expression between primary and metastatic melanoma, as well as correlation between RPL23AP53 and overall survival. No differences depending on BRAF status were observed. RPL23AP53 is associated with several signaling pathways and cellular processes.

Conclusions

This study showed that patients with higher expression of RPL23AP53 displayed changed infiltration of lymphocytes, macrophages, and neutrophils compared to groups with lower expression of RPL23AP53. RPL23AP53 pseudogene is differently expressed in melanoma compared with normal tissue and its expression is associated with cellular proliferation. Thus, it may be considered as an indicator of patients' survival and a marker for the immune profile assessment.

Natural flavonoids alleviate glioblastoma multiforme by regulating long non-coding RNA

Glioblastoma multiforme (GBM) is one of the most common primary malignant brain tumors in adults. Due to the poor prognosis of patients, the median survival time of GBM is often less than 1 year. Therefore, it is very necessary to find novel treatment options with a good prognosis for the treatment or prevention of GBM. In recent years, flavonoids are frequently used to treat cancer. It is a new attractive molecule that may achieve this promising treatment option. Flavonoids have been proved to have many biological functions, such as antioxidation, prevention of angiogenesis, anti-inflammation, inhibition of cancer cell proliferation, and protection of nerve cells. It has also shown the ability to regulate long non-coding RNA (LncRNA). Studies have confirmed that flavonoids can regulate epigenetic modification, transcription, and change microRNA (miRNA) expression of GBM through lncRNA at the gene level. It also found that flavonoids can induce apoptosis and autophagy of GBM cells by regulating lncRNA. Moreover, it can improve the metabolic abnormalities of GBM, interfere with the tumor microenvironment and related signaling pathways, and inhibit the angiogenesis of GBM cells. Eventually, flavonoids can block the tumor initiation, growth, proliferation, differentiation, invasion, and metastasis. In this review, we highlight the role of lncRNA in GBM cancer progression and the influence of flavonoids on lncRNA regulation. And emphasize their expected role in the prevention and treatment of GBM.

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.

The Involvement of Long Non-Coding RNAs in Glioma: From Early Detection to Immunotherapy

Glioma is a brain tumor that arises in the central nervous system and is categorized according to histology and molecular genetic characteristics. Long non-coding RNAs (lncRNAs) are RNAs longer than 200 nucleotides in length. They have been reported to influence significant events such as carcinogenesis, progression, and increased treatment resistance on glioma cells. Long non-coding RNAs promote cell proliferation, migration, epithelial-to-mesenchymal transition and invasion in glioma cells. Various significant advancements in transcriptomic profiling studies have enabled the identification of immune-related long non-coding RNAs as immune cell-specific gene expression regulators that mediates both stimulatory and suppressive immune responses, implying lncRNAs as potential candidates for improving immunotherapy efficacy against tumors and due to the lack of different diagnostic and treatments for glioma, lncRNAs are potential candidates to be used as future diagnostic, prognostic biomarker and treatment tools for glioma. This review’s primary purpose is to concentrate on the role of long non-coding RNAs in early glioma identification, treatment, and immunotherapy.

LncRNA RPSAP52 promotes cell proliferation and inhibits cell apoptosis via modulating miR-665/STAT3 in gastric cancer

LncRNA RPSAP52 is a newly identified functional molecular in several cancers, but its role in gastric cancer (GC) is currently unclear. This study aimed to investigate the biofunction of lncRNA RPSAP52 in GC. Quantitative polymerase-chain reaction (RT-qPCR) was employed to analyze the gene level of lncRNA RPSAP52 and miR-665. Cell proliferation capacity was evaluated via CCK-8 and colony formation assay. Flow cytometry was applied to detect cell cycle and cell apoptosis. Hematoxylin-eosin staining was conducted for histopathological analysis. Immunochemical staining was carried out to detect expression level of ki-67. Subcellular fractionation was performed to explore the position of lncRNA RPSAP52. The binding relationship among lncRNA RPSAP52, miR-665 and STAT3 was verified via luciferase reporter assay. RNA pull down experiments were used to verify the binding relationship between lncRNA RPSAP52 and miR-665. The STAT3 level was evaluated via Western blot. LncRNA RPSAP52 is significantly elevated in GC cells. Deletion of lncRNA RPSAP52 restrained cell proliferation and induced G0-G1 phase arrest, while expediting apoptosis in GC cells. Tumor growth in vivo was suppressed following lncRNA RPSAP52 depletion. MiR-665 was verified as the target of lncRNA RPSAP52. A ceRNA-sponge mechanism of lncRNA RPSAP52 on miR-665 was identified. Meanwhile, miR-665 functions as STAT3 sponge. MiR-665 overexpression and STAT3 depletion served the same functions as lncRNA RPSAP52 depletion in GC cells. LncRNA RPSAP52 exerted anti-cancer effects via modulating miR-665/STAT3 in GC.Abbreviations: Gastric cancer (GC); Quantitative polymerase-chain reaction (RT-qPCR); Helicobacter pylori (H. pylori); Roswell Park Memorial Institute 1640 (RPMI 1640); fetal bovine serum (FBS); glyceraldheyde 3-phosphate dehydrogenase (GAPDH); propidium iodide (PI); Cell counting kit-8 (CCK-8); radioimmunoprecipitation assay (RIPA); sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE); polyvinylidene fluoride (PVDF); enhanced chemiluminescence (ECL); Statistical Product and Service Solutions (SPSS); standard deviation (SD).

Circular RNAs and glioblastoma multiforme: focus on molecular mechanisms

Glioblastoma multiforme (GBM), as a deadly and almost incurable brain cancer, is the most invasive form of CNS tumors that affects both children and adult population. It accounts for approximately half of all primary brain tumors. Despite the remarkable advances in neurosurgery, radiotherapy, and chemotherapeutic approaches, cell heterogeneity and numerous genetic alterations in cell cycle control, cell growth, apoptosis, and cell invasion, result in an undesirable resistance to therapeutic strategies; thereby, the median survival duration for GBM patients is unfortunately still less than two years. Identifying new therapeutics and employing the combination therapies may be considered as wonderful strategies against the GBM. In this regard, circular RNAs (circRNAs), as tumor inhibiting and/or stimulating RNA molecules, can regulate the cancer-developing processes, including cell proliferation, cell apoptosis, invasion, and chemoresistance. Hereupon, these molecules have been introduced as potentially effective therapeutic targets to defeat GBM. The current study aims to investigate the fundamental molecular and cellular mechanisms in association with circRNAs involved in GBM pathogenesis. Among multiple mechanisms, the PI3K/Akt/mTOR, Wnt/β-catenin, and MAPK signaling, angiogenic processes, and metastatic pathways will be thoroughly discussed to provide a comprehensive understanding of the role of circRNAs in pathophysiology of GBM. Video Abstract.

The World of Pseudogenes: New Diagnostic and Therapeutic Targets in Cancers or Still Mystery Molecules?

Pseudogenes were once considered as “junk DNA”, due to loss of their functions as a result of the accumulation of mutations, such as frameshift and presence of premature stop-codons and relocation of genes to inactive heterochromatin regions of the genome. Pseudogenes are divided into two large groups, processed and unprocessed, according to their primary structure and origin. Only 10% of all pseudogenes are transcribed into RNAs and participate in the regulation of parental gene expression at both transcriptional and translational levels through senseRNA (sRNA) and antisense RNA (asRNA). In this review, about 150 pseudogenes in the different types of cancers were analyzed. Part of these pseudogenes seem to be useful in molecular diagnostics and can be detected in various types of biological material including tissue as well as biological fluids (liquid biopsy) using different detection methods. The number of pseudogenes, as well as their function in the human genome, is still unknown. However, thanks to the development of various technologies and bioinformatic tools, it was revealed so far that pseudogenes are involved in the development and progression of certain diseases, especially in cancer.

USP30-AS1 contributes to mitochondrial quality control in glioblastoma cells

Glioblastoma is the most serious type of brain cancer with poor prognosis. Here, using the publicly available glioma database, we identified that USP30-AS1, an antisense lncRNA locating on the opposite strand of USP30 locus, is upregulated in human gliomas, particularly in high grade glioma. High level of USP30-AS1 is correlated with poor survival in both primary and recurrent glioma patients. USP30-AS1 regulates mitochondrial homeostasis and mitophagy in glioblastoma cells. Knockdown of USP30-AS1 decreases mitochondrial protein expression and mitochondrial mass, promotes mitochondrial uncoupler-induced mitophagy. However, USP30-AS1 does not regulate USP30 expression in a cis-regulatory manner. In summary, this study proposed that USP30-AS1 may serve as a valuable prognostic marker for gliomas. USP3-AS1 is a negative regulator of mitophagy and the regulatory effect is USP30-independent. USP30-AS1 mediated repression of mitophagy may contribute to the loss of mitochondrial homeostasis and tumor development in glioma.

lncRNA RPSAP52 induced the development of tongue squamous cell carcinomas via miR-423-5p/MYBL2

Growing lncRNAs have been noted to involve in the initiation and development of several tumours including tongue squamous cell carcinomas (TSCCs). However, the biological role and mechanism of lncRNA RPSAP52 were not well‐explained. We indicated that RPSAP52 was higher in TSCC samples compared with that in control samples. The higher expression of RPSAP52 was positively correlated with higher T stage and TNM stage. Ectopic expression of RPSAP52 induced TSCC cell growth and cycle and induced cytokine secretion including IFN‐γ, IL‐1β and IL‐6, IL‐8, IL‐10 and TGF‐β. We found that the overexpression of RPSAP52 suppressed miR‐423‐5p expression in SCC‐4 cell. miR‐423‐5p was lower in TSCC samples compared with that in control samples, and miR‐423‐5p level was negatively correlated with higher T stage and TNM stage. Pearson's correlation indicated that miR‐423‐5p was negatively associated with that of RPSAP52 in TSCC tissues. Furthermore, MYBL2 was one direct gene of miR‐423‐5p and elevated expression of miR‐423‐5p suppressed MYBL2 expression and ectopic expression of RPSAP52 increased MYBL2 expression in SCC‐4 cell. Finally, we illustrated that RPSAP52 overexpression promoted TSCC cell growth and cycle and induced cytokine secretion including IFN‐γ, IL‐1β and IL‐6, IL‐8, IL‐10 and TGF‐β via modulating MYBL2. These data provided new insight into RPSAP52, which may be one potential treatment target for TSCC.

Long Non-Coding RNA KCNQ1OT1 Promotes Progression of Hepatocellular Carcinoma by miR-148a-3p/IGF1R Axis

Accumulating evidence have suggested that long non-coding RNAs (lncRNAs) act as a critical regulator in tumorgenesis. LncRNA KCNQ1OT1 (KCNQ1OT1) has been recently shown to be dysregulated in many cancers. This study was aimed to explore the biological role of KCNQ1OT1 in hepatocellular carcinoma (HCC). In our study, we first observed the expression level of KCNQ1OT1 was distinctly up-regulated in HCC tissues and cell lines compared with adjacent non-cancer tissues and normal liver cell line. And clinical results indicated that higher expression of KCNQ1OT1 was correlated with poor prognosis of patients with HCC. Next, functional studies revealed that knockdown of KCNQ1OT1 induced apoptosis and repressed proliferation, migration and invasion of HCC cells. In addition, knockdown of KCNQ1OT1 suppressed xenograft tumor growth in vivo. Mechanically, we found that KCNQ1OT1 can promote the expression of IGF1R by functioning as a competing endogenous RNA of miR-148a-3p. In conclusion, our results shown the oncogenic role of KCNQ1OT1 in HCC by regulating the miR-148a-3p/IGF1R axis and may provide a new insight and a potential therapeutic target for HCC.

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

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

Linc01094 Accelerates the Growth and Metastatic-Related Traits of Glioblastoma by Sponging miR-126-5p

Background

Long intergenic non-coding RNAs (lincRNAs) are associated with the progression of glioblastoma (GBM). However, how linc01094 contributes to the growth and metastatic phenotypes of GBM remains not fully studied.

Methods

The expression levels of linc01094 and miR-126-5p in GBM tissues and cell lines were analyzed using qRT-PCR. Loss-of-function experiments were performed to detect the biological activity of linc01094 in GBM. Glioblastoma tumor model was constructed to explore the impact of linc01094 on GBM cell growth in vivo. Linc01094-sponged miR-126-5p was certified by luciferase reporter assay and RNA immunoprecipitation (RIP). The protein expression of miRNA target gene, dynactin subunit 4 (DCTN4) was detected using Western blotting assay.

Results

Herein, we observed that the level of linc01094 was higher in GBM tissues. Silencing of linc01094 restrained the growth and invasive abilities of GBM cell. Moreover, linc01094 level was negatively associated with miR-126-5p level in GBM and linc01094 acted as a “sponge” for miR-126-5p. Reintroduction of linc01094 reversed the tumor-inhibiting effects of miR-126-5p in GBM.

Conclusion

Altogether, linc01094 promoted the tumorigenesis and metastatic phenotypes of GBM cell by modulating of miR-1126-5p/DCTN4 signaling axis.