Identification of long non-coding RNAs that stimulate cell survival in bladder cancer

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.

Long Noncoding RNA LINC00707 Accelerates Tumorigenesis and Progression of Bladder Cancer via Targeting miR-145/CDCA3 Regulatory Loop

INTRODUCTION

Growing studies reveal that long noncoding RNA is involved in oncogenesis and progression. Previous studies have demonstrated that long intergenic noncoding RNA 00707 (LINC00707) stimulated tumor progress in numerous neoplasm types; however, the function of LINC00707 in bladder cancer (BC) was not yet clear. Our researches aimed to determine whether LINC00707 was dysregulated in BC and further study its biological functions.

METHODS

LINC00707 levels in BC tissues and cells were measured using reverse transcription-PCR (RT-PCR), and the associations between the levels of LINC00707 and clinicopathological features and the months of survival were also examined. Then, Cell Counting Kit-8 assays, flow cytometry, colony formation assays, and Transwell assays were applied for the assessment of the impact of LINC00707 on the abilities of BC cells. The interaction between LINC00707 and miR-145 or cell division cycle associated 3 was determined by luciferase reporter system and RT-PCR. Protein expressions of Wnt/β-catenin signaling were examined using RT-PCR and Western blot.

RESULTS

We found that LINC00707 expressions were notably upregulated in BC samples and cells. Higher expressions of LINC00707 were associated with T stage, grade, and shorter overall survival in BC patients. LINC00707 was also an independent prognostic factor for BC. In vitro assays confirmed that silencing LINC00707 expressions suppressed cell proliferation, colony formation, and metastasis. Mechanistic studies elucidated that LINC00707 was directly targeted to miR-145/CDCA3. Western blot assays revealed that Wnt/β-catenin signaling was inactivated by LINC00707 knockdown.

CONCLUSION

Our work offers new insight into the function of LINC00707 in the tumorigenesis of BC.

LINC00963 Functions as an Oncogene in Bladder Cancer by Regulating the miR-766-3p/MTA1 Axis

Purpose

Long non-coding RNAs have been found to be involved in bladder cancer development. This article studied LINC00963 effects on bladder cancer progression to provide a novel treatment target.

Patients and Methods

Totally 56 bladder cancer patients participated in this research. Bladder cancer cells were transfected. Cell counting kit 8 assay and clone formation experiment were used for cell viability and colony formation detection. Cell migration and invasion were determined by Transwell experiment. LINC00963 distribution was explored by cytoplasmic and nuclear extract isolation and quantitative real-time polymerase chain reaction. Luciferase reporter experiment and RNA pulldown experiment were performed to detect the relationship between these two genes. The cancer genome atlas analysis was used for the detection of metastasis-associated protein 1 (MTA1) expression in bladder cancer.

Results

LINC00963 was seriously up-regulated in bladder cancer patients. High LINC00963 expression indicated high histological grade and low survival. LINC00963 was obviously up-regulated in bladder cancer cells. Knockdown of LINC00963 significantly reduced bladder cancer cells viability, colony formation, migration and invasion. Luciferase reporter experiment and RNA pulldown experiment revealed that LINC00963 promoted MTA1 expression via directly inhibiting miR-766-3p. MTA1 was up-regulated in bladder cancer patients. MTA1 up-regulation reversed the inhibitory effect of LINC00963 knockdown on bladder cancer cell viability, migration and invasion.

Conclusion

LINC00963 functions as an oncogene in bladder cancer by regulating the miR-766-3p/MTA1 axis.

LINC00857 expression predicts and mediates the response to platinum-based chemotherapy in muscle-invasive bladder cancer

Approximately 20% of patients with bladder cancer are diagnosed with muscle‐invasive disease (MIBC). The treatment involves radical cystectomy, but almost 50% of patients with MIBC eventually relapse and develop metastasis. The use of platinum‐based chemotherapy in the neoadjuvant setting or for metastatic patients has been shown to improve the overall survival in a subset of patients. Unfortunately, no biomarkers are available to select patients with MIBC who will benefit from chemotherapy or to monitor the efficacy of the treatment. Recently, long noncoding RNAs (lncRNAs) were shown to regulate a variety of processes involved in the development and progression of cancer, including bladder cancer. Moreover, several lncRNAs have been shown to play a role in chemotherapy resistance. Here, we analyzed lncRNA expression associated with response to platinum‐based chemotherapy in metastatic MIBC using data from the MiTranscriptome lncRNA expression database. Expression of the lncRNA,LINC00857, was found to be upregulated in tumors from patients that did not respond to platinum‐based chemotherapy. Moreover, high expression of LINC00857 is correlated with shorter recurrence‐free and overall survival of patients with MIBC. Knockdown of LINC00857 significantly decreased cell viability of bladder cancer cell lines through the induction of apoptosis. Furthermore, LINC00857 knockdown sensitized UM‐UC‐3 and T24 bladder cancer cells to cisplatin, via the negative regulation of the LMAN1 gene. Our data indicate that LINC00857 plays an important role in the regulation of response to platinum‐based chemotherapy. LINC00857 potentially could serve as a novel prognostic and predictive biomarker and might be a therapeutic target to overcome cisplatin resistance in patients with MIBC.

Clinical Values of Long Non-coding RNAs in Bladder Cancer: A Systematic Review

Background: Increasing evidence shows that dysregulated expression of long non-coding RNAs (lncRNAs) can serve as diagnostic or prognostic markers in bladder cancer. The aim of this study was to evaluate the clinical values of dysregulated lncRNAs in bladder cancer.

Methods: Eligible studies were systematically searched in PubMed, Embase, and Web of Science databases from inception to December 2017. Odds ratios (OR) were calculated to investigate the correlation between lncRNAs and clinicopathological parameters. Pooled hazard ratios (HR) and 95% confidence interval (CI) were calculated to explore the prognostic value of lncRNAs in bladder cancer. Pooled diagnostic parameters were also calculated to estimate the performance of lncRNAs in diagnosing bladder cancer. All statistical analyses were performed by using STATA 13.1 program.

Results: A total of 37 relevant studies were included to the present systematic review according to the inclusion and exclusion criteria, including 26 on clinicopathological parameters, 19 on prognosis, and 7 on diagnosis. For clinicopathological parameters, MALAT1 expression was significantly associated with lymph node metastasis (OR = 2.731; 95% CI: 1.409–5.292; p = 0.003), and high-level expression of XIST was related to larger tumor size (OR = 2.473; 95% CI: 1.159–5.276; p = 0.019) and higher TNM stage (OR = 0.400; 95% CI, 0.184–0.868; p = 0.020). For the prognostic values, the most significant association was observed between increased expressions of SPRY4-IT1 and poor overall survival (OS) (HR = 3.716; 95% CI: 2.084–6.719; p < 0.001); high MALAT1 expression was significantly associated with poor OS (HR = 1.611; 95% CI: 1.076–2.412; p = 0.020). For the diagnostic values, UCA1 expression profile achieved a combined AUC of 0.92, with sensitivity of 0.84 and specificity of 0.89 in distinguishing patients with bladder cancer from non-cancerous controls.

Conclusions: In summary, systematic review elaborated that abnormal lncRNAs expression can serve as potential markers for prognostic evaluation in bladder cancer patients. In addition, the diagnostic meta-analysis concluded that abnormally expressed UCA1 can function as potential diagnostic markers for bladder cancer.

mRNA, microRNA and lncRNA as novel bladder tumor markers

Early detection of bladder cancer (BC) is essential for improvement of the patient's prognosis and general survival rates. Current diagnostic methods are still limited, so new specific and cost-effective biomarkers are emerging as the noninvasive tools in treatment decisions in recurrent BC. Gene expression and epigenetic profile can be analysed using quantitative real-time-PCR (qRT-PCR) method in urine, blood and tissue. This review provides an update of recent findings on BC molecular profile as novel markers in diagnosis and prognosis of bladder tumors. We describe mRNA-, microRNA- and lncRNA-based biomarkers involved in the BC detection, diagnosis, prediction of recurrence and monitoring after treatment.