Role of Long Non-coding RNAs on Bladder Cancer

A novel LINC02321 promotes cell proliferation and decreases cisplatin sensitivity in bladder cancer by regulating RUVBL2

Bladder cancer (BC) has a high incidence and is prone to recurrence. In most instances, the low 5-year survival rate of advanced BC patients results from postoperative recurrence and drug resistance. Long noncoding RNAs (lncRNAs) can participate in numerous biological functions by regulating the expression of genes to affect tumorigenesis. Our previous work had demonstrated that a novel lncRNA, LINC02321, was associated with BC prognosis. In this study, A high expression of LINC02321 was found in BC tissues, which was associated with poor prognosis in patients. LINC02321 promoted both proliferation and G1-G0 progression in BC cells, while also inhibited sensitivity to cisplatin. Mechanistically, LINC02321 can bind to RUVBL2 and regulate the expression levels of RUVBL2 protein by affecting its half-life. RUVBL2 is involved in the DNA damage response. The potential of DNA damage repair pathways to exert chemosensitization has been demonstrated in vivo. The rescue experiment demonstrated that RUVBL2 overexpression can markedly abolish the decreased cell proliferation and the increased sensitivity of BC cells to cisplatin caused by LINC02321 knockdown. The results indicate that LINC02321 functions as an oncogene in BC, and may serve as a novel potential target for controlling BC progression and addressing cisplatin resistance in BC therapy.

Non-coding RNA transcripts, incredible modulators of cisplatin chemo-resistance in bladder cancer through operating a broad spectrum of cellular processes and signaling mechanism

Bladder cancer (BC) is a highly frequent neoplasm in correlation with significant rate of morbidity, mortality, and cost. The onset of BC is predominantly triggered by environmental and/or occupational exposures to carcinogens, such as tobacco. There are two distinct pathways by which BC can be developed, including non-muscle-invasive papillary tumors (NMIBC) and non-papillary (or solid) muscle-invasive tumors (MIBC). The Cancer Genome Atlas project has further recognized key genetic drivers of MIBC along with its subtypes with particular properties and therapeutic responses; nonetheless, NMIBC is the predominant BC presentation among the suffering individuals. Radical cystoprostatectomy, radiotherapy, and chemotherapy have been verified to be the common therapeutic interventions in metastatic tumors, among which chemotherapeutics are more conventionally utilized. Although multiple chemo drugs have been broadly administered for BC treatment, cisplatin is reportedly the most effective chemo drug against the corresponding malignancy. Notwithstanding, tumor recurrence is usually occurred following the consumption of cisplatin regimens, particularly due to the progression of chemo-resistant trait. In this framework, non-coding RNAs (ncRNAs), as abundant RNA transcripts arise from the human genome, are introduced to serve as crucial contributors to tumor expansion and cisplatin chemo-resistance in bladder neoplasm. In the current review, we first investigated the best-known ncRNAs, i.e. microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), correlated with cisplatin chemo-resistance in BC cells and tissues. We noticed that these ncRNAs could mediate the BC-related cisplatin-resistant phenotype through diverse cellular processes and signaling mechanisms, reviewed here. Eventually, diagnostic and prognostic potential of ncRNAs, as well as their therapeutic capabilities were highlighted in regard to BC management.

Unveiling therapeutic prospects: targeting MDM-2 in non-muscle invasive bladder cancer

Non-muscle invasive bladder cancer (NMIBC) is considered one of the most costly malignancies, requiring significant surgical and therapeutic measures. However, progression and non-responsiveness to immunotherapy are common outcomes of treatment. In this study, we conducted comparative transcriptomic analysis of non-responders from two distinct populations (Asian and American) and identified six common genes associated with disease prognosis. Among these genes, MDM-2 is a major oncogenic protein linked to seven different types of cancers, as it is involved in the degradation of the tumor suppressor protein p53. To address this, we explored novel therapeutic drugs to block the binding of p53 and MDM-2 using a targeted molecular docking approach. High-throughput screening of 2500 drugs from the FDA-approved drug database led to the identification of three drug compounds: Mol-126, Mol-679, and Mol-768. Subsequently, we evaluated the structural stability and binding of these drugs for the targeted inhibition of the MDM-2 active site (hydrophobic cleft) using molecular dynamics simulations. Analysis of five trajectories, including RMSD, RMSF, hydrogen bond, radius of gyration, coulomb short-range electrostatic spectra, and free binding energy, confirmed that Mol-126 exhibited the highest structural stability compared to the reference drug (Alrizomadlin). Notably, Mol-126 is a derivative of 3-phenoxypropionic acid, which shows promise for the development of alternative therapeutic treatments for non-responsive bladder cancer patients.Communicated by Ramaswamy H. Sarma.

Molecular landscape of LncRNAs in bladder cancer: From drug resistance to novel LncRNA-based therapeutic strategies

Bladder cancer (BC) is a common and serious type of cancer that ranks among the top ten most prevalent malignancies worldwide. Due to the high occurrence rate of BC, the aggressive nature of cancer cells, and their resistance to medication, managing this disease has become a growing challenge in clinical care. Long noncoding RNAs (lncRNAs) are a group of RNA transcripts that do not code for proteins and are more than 200 nucleotides in length. They play a significant role in controlling cellular pathways and molecular interactions during the onset, development and progression of different types of cancers. Recent advancements in high-throughput gene sequencing technology have led to the identification of various differentially expressed lncRNAs in BC, which indicate abnormal expression. In this review, we summarize that these lncRNAs have been found to impact several functions related to the development of BC, including proliferation, cell growth, migration, metastasis, apoptosis, epithelial-mesenchymal transition, and chemo- and radio-resistance. Additionally, lncRNAs may improve prognosis prediction for BC patients, indicating a future use for them as prognostic and diagnostic biomarkers for BC patients. This review highlights that genetic tools and anti-tumor agents, such as CRISPR/Cas systems, siRNA, shRNA, antisense oligonucleotides, and vectors, have been created for use in preclinical cancer models. This has led to a growing interest in using lncRNAs based on positive research findings.

LINC01137/miR-186-5p/WWOX: a novel axis identified from WWOX-related RNA interactome in bladder cancer

Introduction: The discovery of non-coding RNA (ncRNA) dates back to the pre-genomics era, but the progress in this field is still dynamic and leverages current post-genomics solutions. WWOX is a global gene expression modulator that is scarcely investigated for its role in regulating cancer-related ncRNAs. In bladder cancer (BLCA), the link between WWOX and ncRNA remains unexplored. The description of AP-2α and AP-2γ transcription factors, known as WWOX-interacting proteins, is more commonplace regarding ncRNA but still merits investigation. Therefore, this in vitro and in silico study aimed to construct an ncRNA-containing network with WWOX/AP-2 and to investigate the most relevant observation in the context of BLCA cell lines and patients. Methods: RT-112, HT-1376, and CAL-29 cell lines were subjected to two stable lentiviral transductions. High-throughput sequencing of cellular variants (deposited in the Gene Expression Omnibus database under the GSE193659 record) enabled the investigation of WWOX/AP-2-dependent differences using various bioinformatics tools (e.g., limma-voom, FactoMineR, multiple Support Vector Machine Recursive Feature Elimination (mSVM-RFE), miRDB, Arena-Idb, ncFANs, RNAhybrid, TargetScan, Protein Annotation Through Evolutionary Relationships (PANTHER), Gene Transcription Regulation Database (GTRD), or Evaluate Cutpoints) and repositories such as The Cancer Genome Atlas (TCGA) and Cancer Cell Line Encyclopedia. The most relevant observations from cap analysis gene expression sequencing (CAGE-seq) were confirmed using real-time PCR, whereas TCGA data were validated using the GSE31684 cohort. Results: The first stage of the whole study justified focusing solely on WWOX rather than on WWOX combined with AP-2α/γ. The most relevant observation of the developed ncRNA-containing network was LINC01137, i.e., long non-coding RNAs (lncRNAs) that unraveled the core network containing UPF1, ZC3H12A, LINC01137, WWOX, and miR-186-5p, the last three being a novel lncRNA/miRNA/mRNA axis. Patients' data confirmed the LINC01137/miR-186-5p/WWOX relationship and provided a set of dependent genes (i.e., KRT18, HES1, VCP, FTH1, IFITM3, RAB34, and CLU). Together with the core network, the gene set was subjected to survival analysis for both TCGA-BLCA and GSE31684 patients, which indicated that the increased expression of WWOX or LINC01137 is favorable, similar to their combination with each other (WWOX↑ and LINC01137↑) or with MIR186 (WWOX↑/LINC01137↑ but MIR186↓). Conclusion: WWOX is implicated in the positive feedback loop with LINC01137 that sponges WWOX-targeting miR-186-5p. This novel WWOX-containing lncRNA/miRNA/mRNA axis should be further investigated to depict its relationships in a broader context, which could contribute to BLCA research and treatment.

An Overview of Angiogenesis in Bladder Cancer

PURPOSE OF THE REVIEW

Angiogenesis plays a key role in bladder cancer (BC) pathogenesis. In the last two decades, an increasing number of publications depicting a multitude of novel angiogenic molecules and pathways have emerged. The growing complexity necessitates an evaluation of the breadth of current knowledge to highlight key findings and guide future research.

RECENT FINDINGS

Angiogenesis is a dynamic biologic process that is inherently difficult to assess. Clinical assessment of angiogenesis in BCs is advancing with the integration of image analysis systems and dynamic contrast-enhanced and magnetic resonance imaging (DCE-MRI). Tumour-associated macrophages (TAMs) significantly influence the angiogenic process, and further research is needed to assess their potential as therapeutic targets. A rapidly growing list of non-coding RNAs affect angiogenesis in BCs, partly through modulation of vascular endothelial growth factor (VEGF) activity. Vascular mimicry (VM) has been repeatedly associated with increased tumour aggressiveness in BCs. Standardised assays are needed for appropriate identification and quantification of VM channels. This article demonstrates the dynamic and complex nature of the angiogenic process and asserts the need for further studies to deepen our understanding.

m6A-mediated upregulation of lncRNA RMRP boosts the progression of bladder cancer via epigenetically suppressing SCARA5

Aim: This study aimed to elucidate the relationship between SCARA5 and RMRP in bladder cancer and their underlying mechanism. Methods: Biological functions were evaluated using cell-counting kit 8 assay, 5-ethynyl-2'-deoxyuridine incorporation, wound healing and Transwell assays. RNA immunoprecipitation, RNA pull-down and chromatin immunoprecipitation were employed. A xenograft tumor model in nude mice was also conducted. Results & conclusion: RMRP and SCARA5 exhibited an inverse correlation. Downregulation of RMRP significantly suppressed bladder cancer cell proliferation, migration and invasion, which was reversed by SCARA5 overexpression. RMRP recruited DNA methyltransferases to the promoter region of SCARA5, thereby triggering the methylation of the SCARA5 promoter to epigenetically suppress its expression. Our findings elucidate the machinery by which RMRP, stabilized by METTL3, exerts a promoter role in bladder cancer tumorigenesis by triggering SCARA5 methylation.

Potential roles of lncRNA-XIST/miRNAs/mRNAs in human cancer cells

Long non-coding RNAs (lncRNAs) are non-coding RNAs that contain more than 200 nucleotides but do not code for proteins. In tumorigenesis, lncRNAs can have both oncogenic and tumor-suppressive properties. X inactive-specific transcript (XIST) is a known lncRNA that has been implicated in X chromosome silencing in female cells. Dysregulation of XIST is associated with an increased risk of various cancers. Therefore, XIST can be a beneficial prognostic biomarker for human malignancies. In this review, we attempt to summarize the emerging roles of XIST in human cancers.

Non-coding RNA and autophagy: Finding novel ways to improve the diagnostic management of bladder cancer

Major fraction of the human genome is transcribed in to the RNA but is not translated in to any specific functional protein. These transcribed but not translated RNA molecules are called as non-coding RNA (ncRNA). There are thousands of different non-coding RNAs present inside the cells, each regulating different cellular pathway/pathways. Over the last few decades non-coding RNAs have been found to be involved in various diseases including cancer. Non-coding RNAs are reported to function both as tumor enhancer and/or tumor suppressor in almost each type of cancer. Urothelial carcinoma of the urinary bladder is the second most common urogenital malignancy in the world. Over the last few decades, non-coding RNAs were demonstrated to be linked with bladder cancer progression by modulating different signalling pathways and cellular processes such as autophagy, metastasis, drug resistance and tumor proliferation. Due to the heterogeneity of bladder cancer cells more in-depth molecular characterization is needed to identify new diagnostic and treatment options. This review emphasizes the current findings on non-coding RNAs and their relationship with various oncological processes such as autophagy, and their applicability to the pathophysiology of bladder cancer. This may offer an understanding of evolving non-coding RNA-targeted diagnostic tools and new therapeutic approaches for bladder cancer management in the future.

m6A-induced lncDBET promotes the malignant progression of bladder cancer through FABP5-mediated lipid metabolism

The limited effect of adjuvant therapy for advanced bladder cancer (BCa) leads to a poor prognosis. Increasing evidence has shown that RNA N6-methyladenosine (m⁶A) modification plays important functional roles in tumorigenesis. Nevertheless, the role and mechanism of m6A-modified noncoding RNAs (ncRNAs) in BCa remain largely unknown.

Methods: RT-PCR, western blotting and ONCOMINE dataset were used to determine the dominant m⁶A-related enzyme in BCa. M⁶A-lncRNA epitranscriptomic microarray was used to screen candidate targets of METTL14. RT-PCR, MeRIP and TCGA dataset were carried out to confirm the downstream target of METTL14. CHIRP/MS was conducted to identify the candidate proteins binding to lncDBET. RT-PCR, western blotting, RIP and KEGG analysis were used to confirm the target of lncDBET. The levels of METTL14, lncDBET and FABP5 were tested in vitro and in vivo. CCK-8, EdU, transwell and flow cytometry assays were performed to determine the oncogenic function of METTL14, lncDBET and FABP5, and their regulatory networks.

Results: We identified that the m⁶A level of total RNA was elevated and that METTL14 was the dominant m6A-related enzyme in BCa. m⁶A modification mediated by METTL14 promoted the malignant progression of BCa by promoting the expression of lncDBET. Upregulated lncDBET activated the PPAR signalling pathway to promote the lipid metabolism of cancer cells through direct interaction with FABP5, thus promoting the malignant progression of BCa in vitro and in vivo.

Conclusions: Our study establishes METTL14/lncDBET/FABP5 as a critical oncogenic axis in BCa.

Genome-wide Exploration of a Pyroptosis-Related Long Non-Coding RNA Signature Associated With the Prognosis and Immune Response in Patients With Bladder Cancer

Background: Bladder cancer (BLCA) is a malignant tumor with a complex molecular mechanism and high recurrence rate in the urinary system. Studies have shown that pyroptosis regulates tumor cell proliferation and metastasis and affects the prognosis of cancer patients. However, the role of pyroptosis-related (PR) genes or long non-coding RNAs (lncRNAs) in BLCA development is not fully understood.

Methods: We comprehensively analyzed the molecular biological characteristics of PR genes in BLCA, including copy number variation, mutations, expression and prognostic value based on TCGA database. We then identified PR lncRNAs with prognostic value based on the expression of PR genes and performed a consistent clustering analysis of 407 BLCA patients according to the expression of prognosis-related PR lncRNAs and identified two clusters. The least absolute shrinkage and selection operator (LASSO) regression was used to establish a PR lncRNA signature and calculate the risk score associated with the prognosis of patients with BLCA. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA) were used to evaluate the possible functions of PR lncRNA signature. We also evaluated the relationship between the risk score and tumor immune microenvironment (TIME).

Results: A total of 33 PR genes were obtained in our study and 194 prognosis-related PR lncRNAs were identified. We also constructed a signature consisting of eight-PR-lncRNAs and divided patients into high- and low-risk groups. The overall survival rate of patients with a high risk was significantly lower than patients with a low risk. The risk score was significantly correlated with the degree of infiltration of multiple immune cell subtypes and positively correlated with multiple immune checkpoint genes expression in BLCA. Enrichment analyses showed that these lncRNAs are involved in human immune regulatory functions and immune-related pathways.

Conclusion: Our study comprehensively studied the molecular biological characteristics of PR genes BLCA, and the eight-PR-lncRNA signature we identified might play a crucial role in tumor immunity and may be able to predict the prognosis of BLCA patients, providing a theoretical basis for an in-depth study of the relationship between the prognosis and TIME.

Urinary Exosomal Long Noncoding RNA TERC as a Noninvasive Diagnostic and Prognostic Biomarker for Bladder Urothelial Carcinoma

Purpose

Bladder cancer is one of the most common urological malignancies worldwide, and approximately 90% of bladder cancer cases are histologically typed as bladder urothelial carcinoma (BLCA). Exosomes are 30 to 200 nm extracellular vesicles that transport microRNAs, long noncoding RNAs (lncRNAs), mRNAs, circular RNAs, and proteins across tissues and through circulation. Urinary exosomes may contain genetic information from tumor cells. Herein, we explored the clinical significance of urinary exosomal lncRNA telomerase RNA component (TERC) levels to provide an urgently needed diagnostic and prognostic biomarker for BLCA.

Materials and Methods

In this study, we used RNA-sequencing of samples from four BLCA patients and three healthy controls to identify that TERC was differentially expressed in urinary exosomes. We then used quantitative PCR in different types of clinical samples to validate the biomarker and analyzed results using receiver operating characteristic curves.

Results

We found that TERC was significantly upregulated in urinary exosomes from BLCA patients compared with those from healthy controls (P < 0.0001). Urinary exosomal TERC showed higher sensitivity (78.65%) and accuracy (77.78%) than existing indicators including nuclear matrix protein-22 and urine cytometry. Using the cut-off value 4.302, the area under the curve for urinary exosomal TERC was 0.836 (95% confidence interval: 0.768–0.891, P < 0.0001). Furthermore, this noninvasive assay could distinguish low-grade and high-grade tumors (P = 0.0153).

Conclusions

TERC is enriched in urinary exosomes from BLCA patients. Urinary exosomal TERC could become a diagnostic and prognostic biomarker for BLCA that allows clinicians to realize noninvasive detection of BLCA.