Long non-coding RNA urothelial carcinoma associated 1 (UCA1) mediates radiation response in prostate cancer

Critical role of the long non-coding RNAs (lncRNAs) in radiotherapy (RT)-resistance of gastrointestinal (GI) cancer: Is there a way to defeat this resistance?

Radiotherapy (RT) is a frequently used treatment for cervical cancer, effectively decreasing the likelihood of the disease returning in the same area and extending the lifespan of individuals with cervical cancer. Nevertheless, the primary reason for treatment failure in cancer patients is the cancer cells' resistance to radiation therapy (RT). Long non-coding RNAs (LncRNAs) are a subset of RNA molecules that do not code for proteins and are longer than 200 nucleotides. They have a significant impact on the regulation of gastrointestinal (GI) cancers biological processes. Recent research has shown that lncRNAs have a significant impact in controlling the responsiveness of GI cancer to radiation. This review provides a concise overview of the composition and operation of lncRNAs as well as the intricate molecular process behind radiosensitivity in GI cancer. Additionally, it compiles a comprehensive list of lncRNAs that are linked to radiosensitivity in such cancers. Furthermore, it delves into the potential practical implementation of these lncRNAs in modulating radiosensitivity in GI cancer.

The SGLT2 inhibitor canagliflozin suppresses growth and enhances prostate cancer response to radiotherapy

Radiotherapy is a non-invasive standard treatment for prostate cancer (PC). However, PC develops radio-resistance, highlighting a need for agents to improve radiotherapy response. Canagliflozin, an inhibitor of sodium-glucose co-transporter-2, is approved for use in diabetes and heart failure, but is also shown to inhibit PC growth. However, whether canagliflozin can improve radiotherapy response in PC remains unknown. Here, we show that well-tolerated doses of canagliflozin suppress proliferation and survival of androgen-sensitive and insensitive human PC cells and tumors and sensitize them to radiotherapy. Canagliflozin blocks mitochondrial respiration, promotes AMPK activity, inhibits the MAPK and mTOR-p70S6k/4EBP1 pathways, activates cell cycle checkpoints, and inhibits proliferation in part through HIF-1α suppression. Canagliflozin mediates transcriptional reprogramming of several metabolic and survival pathways known to be regulated by ETS and E2F family transcription factors. Genes downregulated by canagliflozin are associated with poor PC prognosis. This study lays the groundwork for clinical investigation of canagliflozin in PC prevention and treatment in combination with radiotherapy.

Importance of long non-coding RNAs in the pathogenesis, diagnosis, and treatment of prostate cancer

Long non-coding RNAs (lncRNAs) are regulatory transcripts with essential roles in the pathogenesis of almost all types of cancers, including prostate cancer. They can act as either oncogenic lncRNAs or tumor suppressor ones in prostate cancer. Small nucleolar RNA host genes are among the mostly assessed oncogenic lncRNAs in this cancer. PCA3 is an example of oncogenic lncRNAs that has been approved as a diagnostic marker in prostate cancer. A number of well-known oncogenic lncRNAs in other cancers such as DANCR, MALAT1, CCAT1, PVT1, TUG1 and NEAT1 have also been shown to act as oncogenes in prostate cancer. On the other hand, LINC00893, LINC01679, MIR22HG, RP1-59D14.5, MAGI2-AS3, NXTAR, FGF14-AS2 and ADAMTS9-AS1 are among lncRNAs that act as tumor suppressors in prostate cancer. LncRNAs can contribute to the pathogenesis of prostate cancer via modulation of androgen receptor (AR) signaling, ubiquitin-proteasome degradation process of AR or other important signaling pathways. The current review summarizes the role of lncRNAs in the evolution of prostate cancer with an especial focus on their importance in design of novel biomarker panels and therapeutic targets.

The exciting encounter between lncRNAs and radiosensitivity in IR-induced DNA damage events

Radiation therapy is a commonly used tool in cancer management due to its ability to destroy malignant tumors. Mechanically, the efficacy of radiotherapy mainly depends on the inherent radiosensitivity of cancer cells and surrounding normal tissues, which mostly accounts for molecular dynamics associated with radiation-induced DNA damage. However, the relationship between radiosensitivity and DNA damage mechanism deserves to be further probed. As the well-established RNA regulators or effectors, long noncoding RNAs (lncRNAs) dominate vital roles in modulating ionizing radiation response by targeting crucial molecular pathways, including DNA damage repair. Recently, emerging evidence has constantly confirmed that overexpression or inhibition of lncRNAs can greatly influence the sensitivity of radiotherapy for many kinds of cancers, by driving a diverse array of DNA damage-associated signaling cascades. In conclusion, this review critically summarizes the recent progress in the molecular mechanism of IR-responsive lncRNAs in the context of radiation-induced DNA damage. The different response of lncRNAs when IR exposure. IR exposure can trigger the changes in expression pattern and subcellular localization of lncRNAs that influences the different radiology processes.

18F-DCFPyL (PSMA) PET as a radiotherapy response assessment tool in metastatic prostate cancer

Background

Prostate Specific Membrane Antigen (PSMA) - positron emission tomography (PET) guides metastasis-directed radiotherapy (MDRT) in prostate cancer (PrCa). However, its value as a treatment response assessment tool after MDRT remains unclear. Importantly, there is limited understanding of the potential of radiotherapy (RT) to alter PSMA gene (folate hydrolase 1; FOLH1) expression.

Methodology

We reviewed a series of 11 men with oligo-metastatic PrCa (25 metastasis sites) treated with MDRT before re-staging with ¹⁸F-DCFPyL (PSMA) PET upon secondary recurrence. Acute effects of RT on PSMA protein and mRNA levels were examined with qPCR and immunoblotting in human wild-type androgen-sensitive (LNCap), castrate-resistant (22RV1) and castrate-resistant neuroendocrine (PC3 and DU145) PrCa cell lines. Xenograft tumors were analyzed with immunohistochemistry. Further, we examined PSMA expression in untreated and irradiated radio-resistant (RR) 22RV1 (22RV1-RR) and DU145 (DU145-RR) cells and xenografts selected for survival after high-dose RT.

Results

The majority of MDRT-treated lesions showed lack of PSMA-PET/CT avidity, suggesting treatment response even after low biological effective dose (BED) MDRT. We observed similar high degree of heterogeneity of PSMA expression in both human specimens and in xenograft tumors. PSMA was highly expressed in LNCap and 22RV1 cells and tumors but not in the neuroendocrine PC3 and DU145 models. Single fraction RT caused detectable reduction in PSMA protein but not in mRNA levels in LNCap cells and did not significantly alter PSMA protein or mRNA levels in tissue culture or xenografts of the other cell lines. However, radio-resistant 22RV1-RR cells and tumors demonstrated marked decrease of PSMA transcript and protein expression over their parental counterparts.

Conclusions

PSMA-PET may be a promising tool to assess RT response in oligo-metastatic PrCa. However, future systematic investigation of this concept should recognize the high degree of heterogeneity of PSMA expression within prostate tumors and the risk for loss of PSMA expression in tumor surviving curative courses of RT.

LncRNA weighted gene co-expression network analysis reveals novel biomarkers related to prostate cancer metastasis

BACKGROUND

Most prostate cancer patients die from metastasis and lack accurate efficacious biomarkers to monitor the disease behavior, optimize treatment and assess prognosis. Herein, we aimed to identify meaningful lncRNA biomarkers associated with prostate cancer metastatic progression.

METHODS

By repurposing microarray probes, 11,624 lncRNAs in prostate cancer were obtained from Gene Expression Omnibus  database (GSE46691, N = 545; GSE29079, N = 235; GSE94767, N = 130). Weighted gene co-expression network analysis was applied to determine the co-expression lncRNA network pertinent to metastasis. Hub lncRNAs were screened. RNA-seq and clinical data from the Cancer Genome Atlas prostate cancer (TCGA-PRAD) cohort (N = 531) were analyzed. Transwell assay and bioinformatic analysis were performed for mechanism research.

RESULTS

The high expression levels of nine hub lncRNAs (FTX, AC005261.1, NORAD, LINC01578, AC004542.2, ZFAS1, EBLN3P, THUMPD3-AS1, GAS5) were significantly associated with Gleason score and increased probability of metastatic progression. Among these lncRNAs, ZFAS1 had the consistent trends of expression in all of the analysis from different cohorts, and the Kaplan-Meier survival analyses showed higher expression of ZFAS1 was associated with shorter relapse free survival. In-vitro studies confirmed that downregulation of ZFAS1 decreased prostate cancer cell migration.

CONCLUSION

We offered some new insights into discovering lncRNA markers correlated with metastatic progression of prostate cancer using the WGCNA. Some may serve as potential prognostic biomarkers and therapeutic targets for advanced metastatic prostate cancer.

Epigenetic regulation of radioresistance: insights from preclinical and clinical studies

INTRODUCTION

Oftentimes, radiation therapy (RT) is ineffective due to the development of radioresistance (RR). However, studies have shown that targeting epigenetic modifiers to enhance radiosensitivity represents a promising direction of clinical investigation.

AREAS COVERED

This review discusses the mechanisms by which epigenetic modifiers alter radiosensitivity through dysregulation of MAPK-ERK and AKT-mTOR signaling. Finally, we discuss the clinical directions for targeting epigenetic modifiers and current radiology techniques used in the clinic.

METHODOLOGY

We searched PubMed and ScienceDirect databases from April 4^th, 2022 to October 18^th, 2022. We examined 226 papers related to radioresistance, epigenetics, MAPK, and PI3K/AKT/mTOR signaling. 194 papers were selected for this review. Keywords used for this search include, 'radioresistance,' 'radiosensitivity,' 'radiation,' 'radiotherapy,' 'particle radiation,' 'photon radiation,' 'epigenetic modifiers,' 'MAPK,' 'AKT,' 'mTOR,' 'cancer,' and 'PI3K.' We examined 41 papers related to clinical trials on the aforementioned topics. Outcomes of interest were safety, overall survival (OS), dose-limiting toxicities (DLT), progression-free survival (PFS), and maximum tolerated dose (MTD).

EXPERT OPINION

Current studies focusing on epigenetic mechanisms of RR strongly support the use of targeting epigenetic modifiers as adjuvants to standard cancer therapies. To further the success of such treatments and their clinical benefit , both preclinical and clinical studies are needed to broaden the scope of known radioresistant mechanisms.

The Involvement of Long Non-Coding RNAs in Glutamine-Metabolic Reprogramming and Therapeutic Resistance in Cancer

Metabolic alterations that support the supply of biosynthetic molecules necessary for rapid and sustained proliferation are characteristic of cancer. Some cancer cells rely on glutamine to maintain their energy requirements for growth. Glutamine is an important metabolite in cells because it not only links to the tricarboxylic acid cycle by producing α-ketoglutarate by glutaminase and glutamate dehydrogenase but also supplies other non-essential amino acids, fatty acids, and components of nucleotide synthesis. Altered glutamine metabolism is associated with cancer cell survival, proliferation, metastasis, and aggression. Furthermore, altered glutamine metabolism is known to be involved in therapeutic resistance. In recent studies, lncRNAs were shown to act on amino acid transporters and glutamine-metabolic enzymes, resulting in the regulation of glutamine metabolism. The lncRNAs involved in the expression of the transporters include the abhydrolase domain containing 11 antisense RNA 1, LINC00857, plasmacytoma variant translocation 1, Myc-induced long non-coding RNA, and opa interacting protein 5 antisense RNA 1, all of which play oncogenic roles. When it comes to the regulation of glutamine-metabolic enzymes, several lncRNAs, including nuclear paraspeckle assembly transcript 1, XLOC_006390, urothelial cancer associated 1, and thymopoietin antisense RNA 1, show oncogenic activities, and others such as antisense lncRNA of glutaminase, lincRNA-p21, and ataxin 8 opposite strand serve as tumor suppressors. In addition, glutamine-dependent cancer cells with lncRNA dysregulation promote cell survival, proliferation, and metastasis by increasing chemo- and radio-resistance. Therefore, understanding the roles of lncRNAs in glutamine metabolism will be helpful for the establishment of therapeutic strategies for glutamine-dependent cancer patients.

Hypofractionated Radiation Versus Conventional Fractionated Radiation: A Network Analysis

Introduction: Conventional fractionation (CF) and hypofractionation (HF) are two radiotherapy methods against cancer, which are applied in medicine. Understanding the efficacy and molecular mechanism of the two methods implies more investigations. In the present study, proteomic findings about the mentioned methods relative to the controls were analyzed via network analysis. Methods: The significant differentially expressed proteins (DEPs) of prostate cancer (PCa) cell line DU145 in response to CF and HF radiation therapy versus controls were extracted from the literature. The protein-protein interaction (PPI) networks were constructed via the STRING database via Cytoscape software. The networks were analyzed by "NetworkAnalyzer" to determine hub DEPs. Results: 126 and 63 significant DEPs were identified for treated DU145 with CF and HF radiation respectively. The PPI networks were constructed by the queried DEPs plus 100 first neighbors. ALB, CD44, THBS1, EPCAM, F2, KRT19, and MCAM were highlighted as common hubs. VTM, OCLN, HSPB1, FLNA, AHSG, and SERPINC1 appeared as the discriminator hub between the studied cells. Conclusion: 70% of the hubs were common between CF and HF conditions, and they induced radio-resistance activity in the survived cells. Six central proteins which discriminate the function of the two groups of the irradiated cells were introduced. On the basis of these findings, it seems that DU145-CF cells, relative to the DU145-UF cells, are more radio-resistant.

LncRNAs as Theragnostic Biomarkers for Predicting Radioresistance in Cancer: A Systematic Review and Meta-Analysis

Background

Radioresistance is the major obstacle after cancer radiotherapy. The dysregulation of long non-coding RNAs (lncRNAs) was closely related the radioresistance response. This meta-analysis was aimed to interpret the relationship between lncRNAs and radiotherapy responses in different cancers.

Method

The studies were selected from databases including PubMed, ISI Web of Science, Embase, Google Scholar, PMC, and CNKI (China National Knowledge Infrastructure). The publication time was limited to before March 20, 2021. The hazard ratios (HRs) and 95% confidence interval were calculated with random-effects models. Subgroup analyses, sensitivity analyses, and publication bias were also conducted.

Result

Twenty-seven lncRNAs in 14 cancer types were investigated, in which 23 lncRNAs were upregulated and four lncRNAs were downregulated. Dysregulation of these lncRNAs were found to be related to radioresistance response. The pooled HR and 95% confidence interval for the combined up-regulated lncRNAs was 1.73 (95% CI=1.50-2.00; P< 0.01) and down-regulated lncRNAs was 2.09 (95% CI= 1.60-2.72; P< 0.01). The HR values of the subgroup analysis for glioma (HR= 2.22, 95% CI= 1.79-2.74; p< 0.01), non-small cell lung cancer (HR=1.48, 95% CI=1.18-1.85; P<0.01), nasopharyngeal carcinoma (HR=4.26; 95% CI= 1.58-11.46; P< 0.01), and breast cancer (HR=1.29; 95% CI= 1.08-1.54; P< 0.01) were obtained. Moreover, the expression of lncRNAs was significantly related to overall survival of patients no matter if the sample size was >50 or not. In addition, the HR values of the subgroup analysis for lncRNA H19 (HR=2.68; 95% CI= 1.92-3.74; P <0.01), lncRNA FAM201A (HR=2.15; 95% CI= 1.15-3.99; P <0.01), and lncRNA HOTAIR (HR=1.22; 95% CI= 0.98-1.54; P =0.08) were also obtained.

Conclusion

LncRNAs can induce cancer radioresistance by regulating cell death-related signaling pathways. Results indicated that lncRNAs, especially lncRNA H19, FAM201A, and HOTAIR, could be considered as a predictive theragnostic biomarker to evaluate radiotherapy response.

Proteomic discovery of non-invasive biomarkers of localized prostate cancer using mass spectrometry

Prostate cancer is the second most frequently diagnosed non-skin cancer in men worldwide. Patient outcomes are remarkably heterogeneous and the best existing clinical prognostic tools such as International Society of Urological Pathology Grade Group, pretreatment serum PSA concentration and T-category, do not accurately predict disease outcome for individual patients. Thus, patients newly diagnosed with prostate cancer are often overtreated or undertreated, reducing quality of life and increasing disease-specific mortality. Biomarkers that can improve the risk stratification of these patients are, therefore, urgently needed. The ideal biomarker in this setting will be non-invasive and affordable, enabling longitudinal evaluation of disease status. Prostatic secretions, urine and blood can be sources of biomarker discovery, validation and clinical implementation, and mass spectrometry can be used to detect and quantify proteins in these fluids. Protein biomarkers currently in use for diagnosis, prognosis and relapse-monitoring of localized prostate cancer in fluids remain centred around PSA and its variants, and opportunities exist for clinically validating novel and complimentary candidate protein biomarkers and deploying them into the clinic.

Autophagy and gastrointestinal cancers: the behind the scenes role of long non-coding RNAs in initiation, progression, and treatment resistance

Gastrointestinal (GI) cancers comprise a heterogeneous group of complex disorders that affect different organs, including esophagus, stomach, gallbladder, liver, biliary tract, pancreas, small intestine, colon, rectum, and anus. Recently, an explosion in nucleic acid-based technologies has led to the discovery of long non-coding RNAs (lncRNAs) that have been found to possess unique regulatory functions. This class of RNAs is >200 nucleotides in length, and is characterized by their lack of protein coding. LncRNAs exert regulatory effects in GI cancer development by affecting different functions such as the proliferation and metastasis of cancer cells, apoptosis, glycolysis and angiogenesis. Over the past few decades, considerable evidence has revealed the important role of autophagy in both GI cancer progression and suppression. In addition, recent studies have confirmed a significant correlation between lncRNAs and the regulation of autophagy. In this review, we summarize how lncRNAs play a behind the scenes role in the pathogenesis of GI cancers through regulation of autophagy.

Targeting long non coding RNA by natural products: Implications for cancer therapy

In spite of achieving substantial progress in its therapeutic strategies, cancer-associated prevalence and mortality are persistently rising globally. However, most malignant cancers either cannot be adequately diagnosed at the primary phase or resist against multiple treatments such as chemotherapy, surgery, radiotherapy as well as targeting therapy. In recent decades, overwhelming evidences have provided more convincing words on the undeniable roles of long non-coding RNAs (lncRNAs) in incidence and development of various cancer types. Recently, phytochemical and nutraceutical compounds have received a great deal of attention due to their inhibitory and stimulatory effects on oncogenic and tumor suppressor lncRNAs respectively that finally may lead to attenuate various processes of cancer cells such as growth, proliferation, metastasis and invasion. Therefore, application of phytochemicals with anticancer characteristics can be considered as an innovative approach for treating cancer and increasing the sensitivity of cancer cells to standard prevailing therapies. The purpose of this review was to investigate the effect of various phytochemicals on regulation of lncRNAs in different human cancer and evaluate their capabilities for cancer treatment and prevention.

Receptor tyrosine kinase ROR1 ameliorates Aβ1-42 induced cytoskeletal instability and is regulated by the miR146a-NEAT1 nexus in Alzheimer's disease

Alzheimer’s disease (AD) involves severe cytoskeletal degradation and microtubule disruption. Here, we studied the altered dynamics of ROR1, a Receptor Tyrosine Kinase (RTK), and how it could counter these abnormalities. We found that in an Aβ_1–42 treated cell model of AD, ROR1 was significantly decreased. Over expressed ROR1 led to the abrogation of cytoskeletal protein degradation, even in the presence of Aβ_1–42, preserved the actin network, altered actin dynamics and promoted neuritogenesis. Bioinformatically predicted miRNAs hsa-miR-146a and 34a were strongly up regulated in the cell model and their over expression repressed ROR1. LncRNA NEAT1, an interactor of these miRNAs, was elevated in mice AD brain and cell model concordantly. RNA Immunoprecipitation confirmed a physical interaction between the miRNAs and NEAT1. Intuitively, a transient knock down of NEAT1 increased their levels. To our knowledge, this is the first instance which implicates ROR1 in AD and proposes its role in preserving the cytoskeleton. The signalling modalities are uniquely analyzed from the regulatory perspectives with miR-146a and miR-34a repressing ROR1 and in turn getting regulated by NEAT1.

Long and short non-coding RNA and radiation response: a review

Once thought of as arising from "junk DNA," noncoding RNAs (ncRNAs) have emerged as key molecules in cellular processes and response to stress. From diseases such as cancer, coronary artery disease, and diabetes to the effects of ionizing radiation (IR), ncRNAs play important roles in disease progression and as biomarkers of damage. Noncoding RNAs regulate cellular processes by competitively binding DNA, mRNA, proteins, and other ncRNAs. Through these interactions, specific ncRNAs can modulate the radiosensitivity of cells and serve as diagnostic and prognostic biomarkers of radiation damage, whether from incidental exposure in radiotherapy or in accidental exposure scenarios. Analysis of RNA expression after radiation exposure has shown alterations not only in mRNAs, but also in ncRNAs (primarily miRNA, circRNA, and lncRNA), implying an important role in cellular stress response. Due to their abundance and stability in serum and other biofluids, ncRNAs also have great potential as minimally invasive biomarkers with advantages over current biodosimetry methods. Several studies have examined changes in ncRNA expression profiles in response to IR and other forms of oxidative stress. Furthermore, some studies have reported modulation of radiosensitivity by altering expression levels of these ncRNAs. This review discusses the roles of ncRNAs in the radiation response and evaluates prior research on ncRNAs as biomarkers of radiation damage. Future directions and applications of ncRNAs in radiation research are introduced, including the potential for a clinical ncRNA assay for assessing radiation damage and for the therapeutic use of RNA interference (RNAi).

A proteomic investigation of isogenic radiation resistant prostate cancer cell lines

To model the problem of radiation resistance in prostate cancer, cell lines mimicking a clinical course of conventionally fractionated or hypofractionated radiotherapy have been generated. Proteomic analysis of radiation resistant and radiosensitive DU145 prostate cancer cells detected 4410 proteins. Over 400 proteins were differentially expressed across both radiation resistant cell lines and pathway analysis revealed enrichment in epithelial to mesenchymal transition, glycolysis and hypoxia. From the radiation resistant protein candidates, the cell surface protein CD44 was identified in the glycolysis and epithelial to mesenchymal transition pathways and may serve as a potential therapeutic target.

Differential CircRNA Expression Signatures May Serve as Potential Novel Biomarkers in Prostate Cancer

Circular RNAs (circRNAs), a recently discovered non-coding RNA, have a number of functions including the regulation of miRNA expression. They have been detected in a number of malignancies including prostate cancer (PCa). The differential expression pattern of circRNAs associated with PCa and androgen receptor (AR) status was investigated in this study. circRNA profiling was performed using a high throughout microarray assay on a panel of prostate cell lines, which consisted of normal, benign, and malignant cells (n = 9). circRNAs were more commonly significantly up-regulated (p < 0.05) than downregulated in malignant cell lines (n = 3,409) vs. benign cell lines (n = 2,949). In a grouped analysis based on AR status, there were 2,127 down-regulated circRNAs in androgen independent cell lines compared to 2,236 in androgen dependent cell lines, thus identifying a potential circRNA signature reflective of androgen dependency. Through a bioinformatics approach, the parental genes associated with the top 10 differentially expressed circRNAs were identified such as hsa_circ_0064644, whose predicted parental gene target is RBMS3, and hsa_circ_0060539, whose predicted gene target is SDC4. Furthermore, we identified three circRNAs associated with the parental gene Caprin1 (hsa_circ_0021652, hsa_circ_0000288, and hsa_circ_0021647). Other studies have shown the importance of Caprin1 in PCa cell survival and drug resistance. Given the modified circRNA expression signatures identified here, these hypothesis generating results suggest that circRNAs may serve as potential putative diagnostic and predictive markers in PCa. However, further validation studies are required to assess the true potential of these markers in the clinical setting.

Long Noncoding RNA UCA1 Is Related to Autophagy and Apoptosis in Endometrial Stromal Cells

Research Question

The expression of the long noncoding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) in embryonic tissues is higher than that in most cancer tissues, such as bladder cancer, indicating that RNA is a carcinoembryonic antigen. However, there are no published reports on the role of UCA1 in endometriosis (EMS). Therefore, to address this gap in knowledge, we assessed the potential role of lncRNA UCA1 in the pathogenesis and progression of EMS.

Design

To verify the expression of UCA1 in EMS, quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used. RNA interference (siRNA) was used to study the biological function of UCA1 in EMS in vitro.

Results

qRT-PCR analysis showed that the expression of lncRNA UCA1 in EMS was increased (P<0.01). Knockdown of UCA1 in vitro significantly inhibited the proliferation of endometrial stromal cells (ESCs) and induced autophagy and apoptosis.

Conclusion

UCA1 is highly expressed in EMS and promotes the proliferation of ESCs but suppresses autophagy and apoptosis. In EMS, UCA1 may be a prognostic marker and therapeutic target.

Reciprocal interactions between tumour cell populations enhance growth and reduce radiation sensitivity in prostate cancer

Intratumoural heterogeneity (ITH) contributes to local recurrence following radiotherapy in prostate cancer. Recent studies also show that ecological interactions between heterogeneous tumour cell populations can lead to resistance in chemotherapy. Here, we evaluated whether interactions between heterogenous populations could impact growth and response to radiotherapy in prostate cancer. Using mixed 3D cultures of parental and radioresistant populations from two prostate cancer cell lines and a predator-prey mathematical model to investigate various types of ecological interactions, we show that reciprocal interactions between heterogeneous populations enhance overall growth and reduce radiation sensitivity. The type of interaction influences the time of regrowth after radiation, and, at the population level, alters the survival and cell cycle of each population without eliminating either one. These interactions can arise from oxygen constraints and from cellular cross-talk that alter the tumour microenvironment. These findings suggest that ecological-type interactions are important in radiation response and could be targeted to reduce local recurrence.

Circ_0062020 Knockdown Strengthens the Radiosensitivity of Prostate Cancer Cells

Background

Prostate cancer (PCa) is a major contributor to reduce the life quality of males. Circular RNAs were frequently reported to be associated with cancers. In the case of radiotherapy to PCa, the role of circ_0062020 was still inconclusive, which was further explored in this study.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the expression of circ_0062020, miR-615-5p and thyroid hormone receptor interactor 13 (TRIP13) in PCa tissues and cells, as well as in normal tissues and cell. Meanwhile, the proliferation of PCa cells was evaluated by clone formation assay and cell counting kit 8 (CCK8) assay. Moreover, the metastasis of PCa cells was assessed by transwell and wound healing assays. Furthermore, the apoptosis of PCa cells was determined by flow cytometry assay. Besides, dual-luciferase reporter system was applied to verify the correlation between miR-615-5p and circ_0062020 or TRIP13, which was predicted by online tool CircRNA interactome or TargetScan. In addition, the protein expression of TRIP13 was measured by Western blot in PCa tissues and cells and normal tissues and cells. Finally, xenograft tumor assay was performed to further confirming the function of circ_0062020 in PCa in vivo.

Results

Circ_0062020 and TRIP13 were upregulated, while miR-615-5p was downregulated in PCa tissues and cells. Circ_0062020 knockdown or miR-615-5p overexpression inhibited the proliferation and metastasis, and promoted apoptosis, which could be reversed by miR-615-5p inhibitor or pc-TRIP13 in ionizing radiation (IR)-treated PCa cells. As expected, circ_0062020 sponged miR-615-5p to regulate TRIP13 expression in PCa cells. Circ_0062020 knockdown also suppressed PCa tumor growth in vivo.

Conclusion

Circ_0062020 suppressed the radiosensitivity by miR-615-5p/TRIP13 axis in PCa cells, which might provide insights into the radiotherapy for PCa.

Long non-coding RNAs in prostate tumorigenesis and therapy (Review)

Prostate cancer (PCa) is one of the most frequently diagnosed malignancy. Although there have been many advances in PCa diagnosis and therapy, the concrete mechanism remains unknown. Long non-coding RNAs (lncRNAs) are novel biomarkers associated with PCa, and their dysregulated expression is closely associated with risk stratification, diagnosis and carcinogenesis. Accumulating evidence has suggested that lncRNAs play important roles in prostate tumorigenesis through relevant pathways, such as androgen receptor interaction and PI3K/Akt. The present review systematically summarized the potential clinical utility of lncRNAs and provided a novel guide for their function in PCa.

Long Non-Coding RNA GAS5 Suppresses Tumor Progression and Enhances the Radiosensitivity of Prostate Cancer Through the miR-320a/RAB21 Axis

Background

Long non-coding RNAs (lncRNAs) function as a class of significant mediators in prostate cancer (PCa), and this study mainly discussed the molecular mechanism of lncRNA growth arrest-specific 5 (GAS5) in PCa progression and radiosensitivity.

Materials and Methods

GAS5 and microRNA-320a (miR-320a) levels were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and migration were severally examined through 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) and transwell assays. PCa cells were treated with X-ray irradiation. Cell survival and apoptosis rate were assayed using colony formation assay and flow cytometry, respectively. The apoptosis-related protein and Rab GTPase 21 (RAB21) protein levels were measured by Western blot. The relation between miR-320a and GAS5 or RAB21 was assessed via the dual-luciferase reporter assay. The effect of GAS5 on radiosensitivity of PCa in vivo was evaluated by xenotransplantation assay.

Results

GAS5 was down-regulated in PCa tissues and cells. GAS5 overexpression suppressed cell viability and migration while facilitated radiosensitivity of PCa cells. GAS5 was a molecular sponge of miR-320a. The effects of GAS5 up-regulation on PCa cells were accomplished by sponging miR-320a. MiR-320a targeted RAB21 and GAS5 up-regulated RAB21 expression via targeting miR-320a. RAB21 knockdown reversed the effects of miR-320a inhibition on PCa cells. GAS5 promoted the radiosensitivity of PCa by the miR-320a/RAB21 axis in vivo.

Conclusion

Collectively, GAS5 restrained tumor development and expedited the radiosensitivity in PCa by the miR-320a/RAB21 axis, which provided a molecular regulatory mechanism of GAS5/miR-320a/RAB21 in PCa development and radioresistance.

Linc-RA1 inhibits autophagy and promotes radioresistance by preventing H2Bub1/USP44 combination in glioma cells

Radiotherapy is one of the standard treatments for glioma patients; however, its clinical efficacy is limited by radioresistance. We identified a mechanism of such resistance mediated by linc-RA1 (radioresistance-associated long intergenic noncoding RNA 1). Linc-RA1 was upregulated in radioresistant glioma cells and glioma tissue samples, compared with radiosensitive cells and nontumor tissues. Linc-RA1 was associated with inferior overall survival and advanced clinical stage of glioma. Linc-RA1 promoted glioma radioresistance in vitro and in vivo. Mechanistically, linc-RA1 stabilized the level of H2B K120 monoubiquitination (H2Bub1) by combining with H2B and inhibiting the interaction between H2Bub1 and ubiquitin-specific protease 44 (USP44), which inhibited autophagy, thus contributing to glioma radioresistance. These results reveal that linc-RA1-mediated autophagy is a key mechanism of radioresistance and is an actionable target for improving radiotherapy efficacy in patients with glioma.

Down-regulation of lncRNA UCA1 enhances radiosensitivity in prostate cancer by suppressing EIF4G1 expression via sponging miR-331-3p

BACKGROUND

We aimed to explore the role of long noncoding RNA urothelial carcinoma-associated 1 (lncRNA UCA1) and its underlying mechanism in the radioresistance of prostate cancer (PCa).

METHODS

QRT-PCR was conducted to measure the expression of UCA1, microRNA-331-3p (miR-331-3p) and eukaryotic translation initiation factor 4 gamma 1 (EIF4G1) in PCa tissues and cells. The relative protein level was determined by western blot assay. Cell proliferation and apoptosis were detected by MTT, colony formation assay, and flow cytometry, respectively. The target interaction between miR-331-3p and UCA1 or EIF4G1 was predicted through bioinformatics analysis, and verified by dual-luciferase reporter gene assay system.

RESULTS

The high levels of UCA1 and EIF4G1 as well as the low level of miR-331-3p were observed in PCa tissues and cell lines. UCA1 and EIF4G1 expression were significantly upregulated by Gy radiation treatement. UCA1 or EIF4G1 knockdown repressed cell growth and enhanced cell apoptosis in 22RV1 and DU145 cells under radiation. Moreover, overexpression of EIF4G1 abolished UCA1 knockdown-induced effect on 6 Gy irradiated PCa cells. UCA1 sponged miR-331-3p to regulate EIF4G1 expression.

CONCLUSIONS

LncRNA UCA1 deletion suppressed the radioresistance to PCa by suppressing EIF4G1 expression via miR-331-3p. UCA1 acted as a potential regulator of radioresistance of PCa, providing a promising therapeutic target for PCa.

Knockdown of Circ_CCNB2 Sensitizes Prostate Cancer to Radiation Through Repressing Autophagy by the miR-30b-5p/KIF18A Axis

Background: Circular RNAs (circRNAs) have recently emerged as crucial regulatory molecules in prostate cancer (PCa), but few researches focus on the effects of circRNAs on PCa radiosensitivity. The issue will be addressed in this study using circRNA Cyclin B2 (circ_CCNB2) as an object. Materials and Methods: All RNA and protein levels were severally examined using quantitative real-time polymerase chain reaction and Western blot. Colony formation assay and flow cytometry were implemented for detecting cell colony capacity and apoptotic cells, respectively. Cellular migration and invasion abilities were evaluated by transwell assay. The combination between potential target molecules was analyzed by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. The effect of circ_CCNB2 on PCa radiosensitivity in vivo was explored using xenograft models in mice. Results: Circ_CCNB2 was upregulated in irradiation-resistant PCa tissues and cells. Circ_CCNB2 knockdown had promoted effect on the radiosensitivity of irradiation-resistant PCa cells by inhibiting autophagy. Besides, circ_CCNB2 could directly sponge miR-30b-5p, and the promotion of circ_CCNB2 knockdown on PCa radiosensitivity was achieved by elevating miR-30b-5p. MiR-30b-5p enhanced the radiosensitivity of irradiation-resistant PCa cells through repressing the expression of its target kinesin family member 18A (KIF18A). Furthermore, circ_CCNB2 regulated the KIF18A level through targeting miR-30b-5p. Circ_CCNB2 downregulation facilitated PCa radiosensitivity in vivo through inhibiting autophagy by miR-30b-5p/KIF18A. Conclusions: In this study, knockdown of circ_CCNB2 was shown to promote PCa radiosensitivity through autophagy repression by miR-30b-5p/KIF18A axis, developing a molecular resistance mechanism of PCa radiotherapy and a feasible strategy to increase radiosensitivity.

Non-Coding RNAs in Cancer Radiosensitivity: MicroRNAs and lncRNAs as Regulators of Radiation-Induced Signaling Pathways

Radiotherapy is a cancer treatment that applies high doses of ionizing radiation to induce cell death, mainly by triggering DNA double-strand breaks. The outcome of radiotherapy greatly depends on radiosensitivity of cancer cells, which is determined by multiple proteins and cellular processes. In this review, we summarize current knowledge on the role of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), in determining the response to radiation. Non-coding RNAs modulate ionizing radiation response by targeting key signaling pathways, including DNA damage repair, apoptosis, glycolysis, cell cycle arrest, and autophagy. Additionally, we indicate miRNAs and lncRNAs that upon overexpression or inhibition alter cellular radiosensitivity. Current data indicate the potential of using specific non-coding RNAs as modulators of cellular radiosensitivity to improve outcome of radiotherapy.

Identifying Long Non-coding RNA of Prostate Cancer Associated With Radioresponse by Comprehensive Bioinformatics Analysis

Although radiotherapy is greatly successful in the treatment of prostate cancer (PCa), radioresistance is still a major challenge in the treatment. To our knowledge, this study is the first to screen long non-coding RNAs (lncRNAs) associated with radioresponse in PCa by The Cancer Genome Atlas (TCGA). Bioinformatics methods were used to identify the differentially expressed lncRNAs and protein-coding genes (PCGs) between complete response (CR) and non-complete response (non-CR) groups in radiotherapy. Statistical methods were applied to identify the correlation between lncRNAs and radioresponse as well as lncRNAs and PCGs. The correlation between PCGs and radioresponse was analyzed using weighted gene co-expression network analysis (WGCNA). The three online databases were used to predict the potential target miRNAs of lncRNAs and the miRNAs that might regulate PCGs. RT-qPCR was utilized to detect the expression of lncRNAs and PCGs in our PCa patients. A total of 65 differentially expressed lncRNAs and 468 differentially expressed PCGs were found between the two groups of PCa. After the chi-square test, LINC01600 was selected to be highly correlated with radioresponse from the 65 differentially expressed lncRNAs. Pearson correlation analysis found 558 PCGs co-expressed with LINC01600. WGCNA identified the darkred module associated with radioresponse in PCa. After taking the intersection of the darkred module of WGCNA, differentially expressed PCGs between the two groups of PCa, and the PCGs co-expressed with LINC01600, three PCGs, that is, JUND, ZFP36, and ATF3 were identified as the potential target PCGs of LINC01600. More importantly, we detected the expression of LINC01600 and three PCGs using our PCa patients, and finally verified that LINC01600 and JUND were differentially expressed between CR and non-CR groups, excluding ZFP36 and ATF3. Meantime, the potential regulation ability of LINC01600 for JUND in PCa cell lines was initially explored. In addition, we constructed the competing endogenous RNA (ceRNA) network of LINC01600—miRNA—JUND. In conclusion, we initially reveal the association of LINC01600 with radioresponse in PCa and identify its potential target PCGs for further basic and clinical research.

Role of non-coding RNAs and RNA modifiers in cancer therapy resistance

As the standard treatments for cancer, chemotherapy and radiotherapy have been widely applied to clinical practice worldwide. However, the resistance to cancer therapies is a major challenge in clinics and scientific research, resulting in tumor recurrence and metastasis. The mechanisms of therapy resistance are complicated and result from multiple factors. Among them, non-coding RNAs (ncRNAs), along with their modifiers, have been investigated to play key roles in regulating tumor development and mediating therapy resistance within various cancers, such as hepatocellular carcinoma, breast cancer, lung cancer, gastric cancer, etc. In this review, we attempt to elucidate the mechanisms underlying ncRNA/modifier-modulated resistance to chemotherapy and radiotherapy, providing some therapeutic potential points for future cancer treatment.

Long non-coding RNAs in genitourinary malignancies: a whole new world

Long non-coding RNAs (lncRNAs) are regulators of cellular machinery that are commonly dysregulated in genitourinary malignancies. Accordingly, the investigation of lncRNAs is improving our understanding of genitourinary cancers, from development to progression and dissemination. lncRNAs are involved in major oncogenic events in genitourinary malignancies, including androgen receptor (AR) signalling in prostate cancer, hypoxia-inducible factor (HIF) pathway activation in renal cell carcinoma and invasiveness in bladder cancer, as well as multiple other proliferation and survival mechanisms. In line with their putative oncogenic roles, new lncRNA-based classifications are emerging as potent predictors of prognosis. In clinical practice, detection of oncogenic lncRNAs in serum or urine might enable early cancer detection, and lncRNAs might also be promising therapeutic targets for patients with genitourinary cancer. Furthermore, as predictors of sensitivity to anticancer treatments, lncRNAs could be integrated into future precision medicine strategies. Overall, lncRNAs are promising new candidates for molecular studies and for discovery of innovative biomarkers and are putative therapeutic targets in genitourinary oncology.

The long non-coding RNA, urothelial carcinoma associated 1, promotes cell growth, invasion, migration, and chemo-resistance in glioma through Wnt/β-catenin signaling pathway

The long non-coding RNA, urothelial carcinoma associated 1 (UCA1) has been demonstrated to play important roles in various types of cancers. This study investigated the functional role of UCA1 in glioma and explored the underlying molecular mechanisms. UCA1 was found to be highly up-regulated in glioma cells, and knock-down of UCA1 inhibited cell growth, invasion and migration, and also induced apoptosis in glioma cells. On the other hand, overexpression of UCA1 promoted cell proliferation, cell invasion and migration in glioma cells. Knock-down of UCA1 suppressed the activity of Wnt/β-catenin signaling, and treatment with lithium chloride restored the inhibitory effect of UCA1 knock-down on cell invasion and migration. More importantly, the aberrant expression of UCA1 was associated with chemo-resistance to cisplatin and temozolomide in glioma cells via interacting with Wnt/β-catenin signaling. In vivo studies showed that overexpression of UCA1 promoted the in vivo tumor growth of U87 cells in the nude mice. Clinically, UCA1 was found to be up-regulated in glioma tissues and higher expression level of UCA1 was correlated with poor survival in patients with glioma. Taken together, our results showed that UCA1 had a functional role in the regulation of glioma cell growth, invasion and migration, and chemo-resistance possibly via Wnt/β-catenin signaling pathway.

Assessment of biochemical recurrence of prostate cancer (Review)

The assessment of the risk of biochemical recurrence (BCR) is critical in the management of males with prostate cancer (PC). Over the past decades, a comprehensive effort has been focusing on improving risk stratification; a variety of models have been constructed using PC-associated pathological features and molecular alterations occurring at the genome, protein and RNA level. Alterations in RNA expression (lncRNA, miRNA and mRNA) constitute the largest proportion of the biomarkers of BCR. In this article, we systemically review RNA-based BCR biomarkers reported in PubMed according to the PRISMA guidelines. Individual miRNAs, mRNAs, lncRNAs and multi-gene panels, including the commercially available signatures, Oncotype DX and Prolaris, will be discussed; details related to cohort size, hazard ratio and 95% confidence intervals will be provided. Mechanistically, these individual biomarkers affect multiple pathways critical to tumorigenesis and progression, including epithelial-mesenchymal transition (EMT), phosphatase and tensin homolog (PTEN), Wnt, growth factor receptor, cell proliferation, immune checkpoints and others. This variety in the mechanisms involved not only validates their associations with BCR, but also highlights the need for the coverage of multiple pathways in order to effectively stratify the risk of BCR. Updates of novel biomarkers and their mechanistic insights are considered, which suggests new avenues to pursue in the prediction of BCR. Additionally, the management of patients with BCR and the potential utility of the stratification of the risk of BCR in salvage treatment decision making for these patients are briefly covered. Limitations will also be discussed.

UCA1 long non-coding RNA: An update on its roles in malignant behavior of cancers

The lncRNA urothelial carcinoma-associated 1 (UCA1) is a 1.4 kb long transcript which has been firstly recognized in human bladder cancer cell line. Subsequent studies revealed its over-expression in a wide array of human cancer cell lines and patients' samples. In addition to conferring malignant phenotype to cells, it enhances resistance to conventional anti-cancer drugs. Moreover, transcript levels of this lncRNA have been regarded as diagnostic markers in several cancer types including gastric, bladder and liver cancers. The underlying mechanism of its participation in carcinogenesis has been identified in some cancer types. Sponging tumor suppressor miRNAs, interacting with cancer-promoting signaling pathways and enhancing cell cycle progression are among these mechanisms. Although few studies have shown anti-carcinogenic properties for this lncRNA, the bulk of evidence supports its oncogenic roles. In the current study, we have reviewed the current literature on the role of UCA1 in the carcinogenic process based on the results of in vitro studies, investigations in animal models and assessment of UCA1 expression in clinical samples.

Molecular mechanisms of lncRNAs in regulating cancer cell radiosensitivity

Radiotherapy is one of the main modalities of cancer treatment. However, tumor recurrence following radiotherapy occurs in many cancer patients. A key to solving this problem is the optimization of radiosensitivity. In recent years, long non-coding RNAs (lncRNAs), which affect the occurrence and development of tumors through a variety of mechanisms, have become a popular research topic. LncRNAs have been found to influence radiosensitivity by regulating various mechanisms, including DNA damage repair, cell cycle arrest, apoptosis, cancer stem cells regulation, epithelial-mesenchymal transition, and autophagy. LncRNAs are expected to become a potential therapeutic target for radiotherapy in the future. This article reviews recent advances in the role and mechanism of lncRNAs in tumor radiosensitivity.

Long non-coding RNAs in prostate cancer: Functional roles and clinical implications

Long noncoding RNAs (lncRNAs) are defined as RNA transcripts longer than 200 nucleotides that do not encode proteins. LncRNAs have been documented to exhibit aberrant expression in various types of cancer, including prostate cancer. Currently, screening for prostate cancer results in overdiagnosis. The consequent overtreatment of patients with indolent disease in the clinic is due to the lack of appropriately sensitive and specific biomarkers. Thus, the identification of lncRNAs as novel biomarkers and therapeutic targets for prostate cancer is promising. In the present review, we attempt to summarize the current knowledge of lncRNA expression patterns and mechanisms in prostate cancer. In particular, we focus on lncRNAs regulated by the androgen receptor and the specific molecular mechanism of lncRNAs in prostate cancer to provide a potential clinical therapeutic strategy for prostate cancer.

The evolution of long noncoding RNA acceptance in prostate cancer initiation, progression, and its clinical utility in disease management

CONTEXT

It is increasingly evident that non-protein-coding regions of the genome can give rise to transcripts that form functional layers of the cancer genome. One of most abundant classes in these regions is long noncoding RNAs (lncRNAs). They have gained increasing attention in prostate cancer (PCa) and paved the way for a greater understanding of these cryptic regulators in cancer.

OBJECTIVE

To review current research exploring the functional biology of lncRNAs in PCa over the past three decades.

EVIDENCE ACQUISITION

A systematic review was performed using PubMed to search for reports with terms "long noncoding RNA", "prostate", and "cancer" over the past 30 yr (1988-2018).

EVIDENCE SYNTHESIS

We comprehensively surveyed the literature collected and summarise experiments leading to the characterisation of lncRNAs in PCa. A historical timeline of lncRNA identification is described, where each lncRNA is categorised mechanistically and within the primary areas of carcinogenesis: tumour risk and initiation, tumour promotion, tumour suppression, and tumour treatment resistance. We describe select lncRNAs that exemplify these areas. We also review whether these lncRNAs have a clinical utility in PCa diagnosis, prognosis, and prediction, and as therapeutic targets.

CONCLUSIONS

The biology of lncRNA is multifaceted, demonstrating a complex array of molecular and cellular functions. These studies reveal that lncRNAs are involved in every stage of PCa. Their clinical utility for diagnosis, prognosis, and prediction of PCa is well supported, but further evaluation for their therapeutic candidacy is needed. We provide a detailed resource and view inside the lncRNA landscape for other cancer biologists, oncologists, and clinicians.

PATIENT SUMMARY

In this study, we review current knowledge of the non-protein-coding genome in prostate cancer (PCa). We conclude that many of these regions are functional and a source of accurate biomarkers in PCa. With a strong research foundation, they hold promise as future therapeutic targets, yet clinical trials are necessary to determine their intrinsic value to PCa disease management.

The prognostic value and mechanisms of lncRNA UCA1 in human cancer

Long noncoding RNAs (lncRNAs), longer than 200 nucleotides in length, play important roles in the development and progression of various cancers. An increasing number of studies have revealed that lncRNAs function as potential oncogenes or tumor suppressors to influence biological processes, such as cell growth, invasion, migration and apoptosis. Urothelial carcinoma associated 1 (UCA1), an oncogenic lncRNA, was first found in bladder cancer and highly expressed in multiple cancers, including gastric cancer, colorectal cancer, lung cancer and breast cancer. UCA1 promotes tumorigenesis mainly via binding to tumor-suppressive microRNAs (miRNAs), activating several pivotal signaling pathways and alteration of epigenetic and transcriptional regulation. In addition, high expression of UCA1 is related to poor clinicopathological features especially for shorter overall survival, suggesting that UCA1 might be regarded as a prognosis biomarker in human cancers. In the present review, we summarized current studies on UCA1 to explore its prognostic value and underlying regulation mechanisms in the development of multiple cancers in order to provide a glimmer of hope for the prevention and treatment of malignant tumors.

Competing Endogenous RNA and Coexpression Network Analysis for Identification of Potential Biomarkers and Therapeutics in association with Metastasis Risk and Progression of Prostate Cancer

Prostate cancer (PCa) is the most frequently diagnosed malignant neoplasm in men. Despite the high incidence, the underlying pathogenic mechanisms of PCa are still largely unknown, which limits the therapeutic options and leads to poor prognosis. Herein, based on the expression profiles from The Cancer Genome Atlas (TCGA) database, we investigated the interactions between long noncoding RNA (lncRNA) and mRNA by constructing a competing endogenous RNA network. Several competing endogenous RNAs could participate in the tumorigenesis of PCa. Six lncRNA signatures were identified as potential candidates associated with stage progression by the Kolmogorov-Smirnov test. In addition, 32 signatures from the coexpression network had potential diagnostic value for PCa lymphatic metastasis using machine learning algorithms. By targeting the coexpression network, the antifungal compound econazole was screened out for PCa treatment. Econazole could induce growth restraint, arrest the cell cycle, lead to apoptosis, inhibit migration, invasion, and adhesion in PC3 and DU145 cell lines, and inhibit the growth of prostate xenografts in nude mice. This systematic characterization of lncRNAs, microRNAs, and mRNAs in the risk of metastasis and progression of PCa will aid in the identification of candidate prognostic biomarkers and potential therapeutic drugs.

Upregulated lncRNA-UCA1 contributes to metastasis of bile duct carcinoma through regulation of miR-122/CLIC1 and activation of the ERK/MAPK signaling pathway

In the present study, we aimed to identify specific lncRNAs and miRNAs, as well as mRNAs, involved in bile duct carcinoma (BDC) and to further explore the way in which lncRNA UCA1 regulates cell metastasis ability. Differentially expressed RNAs were screened out from the TCGA database. In in vitro experiments, qRT-PCR was used to measure lncRNA UCA1, miR-122 and CLIC1 expression. We performed a dual luciferase assay to validate the target relationships among UCA1, CLIC1 and miR-122. The cell migration ability was measured by a wound healing assay, and Transwell assays were applied to detect cell invasive ability. Western blot analysis was employed to detect the expression of related proteins in the MAPK signaling pathway. According to the bioinformatics analysis, lncRNA UCA1 and CLIC1 were both significantly upregulated in BDC, while the expression of miR-122 declined compared with the normal group. The target relationship among UCA1, CLIC1 and miR-122 was verified. UCA1 promoted BDC cell migration and invasiveness, while miR-122 inhibited their progression. CLIC1 served as the downstream target gene of miR-122 and had opposite effects. The ERK/MAPK signaling pathway was activated after upregulating UCA1. LncRNA-UCA1 promoted the metastasis of BDC cells by regulating the expression of miR-122 and its downstream gene mRNA CLIC1 and promoted the activation of the ERK/MAPK pathway, which expanded the horizons of targeted therapy of cholangiocarcinoma.

LncRNA UCA1 promotes tumor metastasis by inducing miR-203/ZEB2 axis in gastric cancer

Increasing studies showed that long-noncoding RNAs (lncRNAs) play important roles in the biological processes, including cancer initiation and progression. However, little is known about the exact role and regulation mechanism of lncRNA UCA1 during the progression of gastric cancer (GC). In this study, we found that UCA1 was aberrantly elevated in gastric cancer tissues, and was significantly associated with lymph node metastasis and TNM stage. In vivo and in vitro, enforced UCA1 level promoted cell migration and invasion of GC cell. Depleted UCA1 expression level attenuated the ability of cell migration and invasion in GC. And then, we detected that expression level of ZEB2, a transcription factor related to tumor metastasis, was regulated by UCA1 in GC cells. miR-203 targets and suppresses to ZEB2 expression. Furthermore, we found that UCA1 could directly interact with miR-203 and lead to the release of miR-203-targeted transcripts ZEB2. Herein, we revealed the novel mechanism of UCA1 on regulating metastasis-related gene by sponge regulatory axis during GC metastasis. Our findings indicated that UCA1 plays a critical role in metastatic GC by mediating sponge regulatory axis miR-203/ZEB2. To explore function of UCA1-miR-203-ZEB2 axis may provide an informative biomarker of malignancy and a highly selective anti-GC therapeutic target.

Inhibition of long non-coding RNA HOTAIR enhances radiosensitivity via regulating autophagy in pancreatic cancer

Background

Resistance to radiation therapy is still a challenge for treatment of pancreatic cancer(PC). Long non-coding RNAs (lncRNA) HOTAIR has been found to play a oncogenic role in several cancers. However, the correlation between HOTAIR and radiotherapy in PC is still unclear.

Methods

TCGA data was collected to analyze the expression of HOTAIR and its relationship with PC progression. A series of functional experiments were conducted to explore the role of HOTAIR in PC radiosensitivity and its underlying molecular mechanisms.

Results

By the analysis of the TCGA data, we found HOTAIR expression in PC tissues was significantly higher than normal tissues and associated with tumor progression. The function analysis showed HOTAIR was enriched in biological regulation and response to stimulus. And in vitro study, the expression of HOTAIR was increased in PANC-1 and AsPC-1 cells after radiation. We identified that HOTAIR knockdown could enhance radiosensitivity and influence autophagy by up-regulating ATG7 expression in PC cells. By futher rescue experiments using rapamycin, activation of autophagy could reversed the the inhibition of cell proliferation and colony formation, as well as promotion of apoptosis mediated by HOTAIR knockdown, indicating that HOTAIR knockdown promoted radiosensitivity of PC cells by regulating autophagy.

Conclusion

Our finding revealed the the regulatory role of HOTAIR in radiosensitivity and provided a a new sight to improve radiotherapy effciency in PC.

Knockdown of long noncoding RNA urothelial carcinoma associated 1 inhibits colorectal cancer cell proliferation and promotes apoptosis via modulating autophagy

Long noncoding RNA urothelial carcinoma associated 1 (UCA1) has been implicated in the growth and metastasis of colorectal cancer (CRC), and autophagy contributes to tumorigenesis and cancer cell survival. However, the regulatory role of UCA1 in CRC cell viability by modulating autophagy remains unclear. In the present study, a significant positive correlation was observed between UCA1 and microtubule-associated protein 1 light chain 3 (LC3) levels, and the elevated UCA1 was negatively correlated with the PKB/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway in 293T cells. Downregulation of UCA1 inhibited autophagy activation and cell proliferation, whereas the apoptosis was increased and the cell cycle was arrested in G2 stage. The next results showed that UCA1 was markedly upregulated in Caco-2 cells. Knockdown of UCA1 significantly decreased the LC3-II and autophagy-related gene 5 (ATG5) protein levels and resulted in an increase in p62 expression. Conversely, the autophagy activator rapamycin (RAPA) reversed the effects. Furthermore, downregulated UCA1 decreased Caco-2 cells population in the G1 phase and increased the cells number in G2 phage. The cell proliferation was inhibited, and apoptosis rate was promoted. More important, RAPA could also abrogate the changes induced by knockdown of UCA1. Collectively, these data demonstrated that downregulated UCA1 induced autophagy inhibition, resulting in suppressing cell proliferation and promoting apoptosis, which suggested that UCA1 might serve as a potential new oncogene to regulate CRC cells viability by modulating autophagy.

Knockdown of lncRNA UCA1 inhibits proliferation and invasion of papillary thyroid carcinoma through regulating miR-204/IGFBP5 axis

Background

Long noncoding RNA (LncRNA) UCA1 has been reported to function as an oncogene in multiple cancers. However, the biological roles and underlying mechanism of UCA1 in papillary thyroid carcinoma (PTC) remain unclear. This study aimed to investigate the underlying function of UCA1 on thyroid cancer progression.

Materials and methods

A series of experiments involving Cell Counting Kit-8, wound-healing, and transwell invasion assays were conducted to determine the cellular capabilities of proliferation, migration, and invasion, respectively. Binding sites between UCA1 and miR-204 were identified using a luciferase reporter system, whereas mRNA and protein expression of target genes were determined by real-time quantitative reverse transcription-PCR (qRT-PCR) and Western blot, respectively.

Results

The results revealed that UCA1 was upregulated in PTC tissue and cell lines. UCA1 knockdown significantly suppressed the cell proliferation, migration, and invasion of TPC-1 cells. Bioinformatics analysis and luciferase reporter assay verified the complementary binding within UCA1 and miR-204 at the 3′-UTR. Moreover, miR-204 inhibition reversed the UCA1 knockdown-mediated inhibitory effect on cell proliferation, migration, and invasion. We also found that UCA1 could regulate expression of IGFBP5, a direct target of miR-204 in PTC.

Conclusion

Our study demonstrated that UCA1 exerts activity of oncogenes in PTC through regulating miR-204/IGFBP5 axis.

Pathological bases and clinical impact of long noncoding RNAs in prostate cancer: a new budding star

Long non-coding RNAs (lncRNAs) are functional RNAs longer than 200 nucleotides. Recent advances in the non-protein coding part of human genome analysis have discovered extensive transcription of large RNA transcripts that lack coding protein function, termed non-coding RNA (ncRNA). It is becoming evident that lncRNAs may be an important class of pervasive genes involved in carcinogenesis and metastasis. However, the biological and molecular mechanisms of lncRNAs in diverse diseases are not yet fully understood. Thus, it is anticipated that more efforts should be made to clarify the lncRNA world. Moreover, accumulating evidence has demonstrated that many lncRNAs are dysregulated in prostate cancer (PC) and closely related to tumorigenesis, metastasis, and prognosis or diagnosis. In this review, we will briefly outline the regulation and functional role of lncRNAs in PC. Finally, we discussed the potential of lncRNAs as prospective novel targets in PC treatment and biomarkers for PC diagnosis.

Long non‑coding RNA urothelial cancer associated 1 regulates radioresistance via the hexokinase 2/glycolytic pathway in cervical cancer

Cervical cancer is one of the most common types of female malignant tumor. It is well established that radiotherapy (RT) is the first‑line treatment of cervical cancer; however, radioresistance is a substantial obstacle to cervical cancer RT. At present, the mechanism underlying radioresistance remains unclear. Emerging evidence has demonstrated that long non‑coding RNAs (lncRNAs) function as crucial regulators of diverse cancers. Aerobic glycolysis, which is a common phenomenon in cancer cells, is associated with various biological functions, including radioresistance. To the best of our knowledge, the present study is the first to explore the role of the lncRNA urothelial cancer associated 1 (UCA1) in cervical cancer radioresistance. In the present study, irradiation was used to establish irradiation‑resistant (IRR) cells, after which a clonogenic survival assay was used to validate radioresistance, reverse transcription‑quantitative polymerase chain reaction was used to evaluate the expression levels of UCA1 and western blotting was conducted to detect the expression levels of glycolysis‑related proteins. In addition, a glucose/lactate assay kit was used to evaluate glucose/lactate concentrations and cells were transfected with small interfering RNA/pcDNA to regulate the expression of UCA1. Following the establishment of IRR cell lines (SiHa‑IRR and HeLa‑IRR), it was demonstrated that SiHa‑IRR and HeLa‑IRR cells exhibited increased expression levels of UCA1 and enhanced glycolysis. Dysregulation of UCA1 and inhibition of glycolysis affected radioresistance of cervical cancer cells. In addition, the results indicated that UCA1 promoted radioresistance‑associated glycolysis in SiHa‑IRR and HeLa‑IRR cells, with the enzyme hexokinase 2 (HK2) acting as a significant regulator in this process. Inhibiting glycolysis by 2‑DG reversed the effects of UCA1 overexpression on HK2 protein expression and radioresistance in SiHa and HeLa cells. Taken together, these findings suggested that UCA1 may have an important role in regulating radioresistance through the HK2/glycolytic pathway, providing novel potential targets to improve cervical cancer RT.

Differentiation of Normal and Radioresistant Prostate Cancer Xenografts Using Magnetization Transfer-Prepared MRI

The ability of MRI to differentiate between normal and radioresistant cancer was investigated in prostate tumour xenografts in mice. Specifically, the process of magnetization exchange between water and other molecules was studied. It was found that magnetization transfer from semisolid macromolecules (MT) and chemical exchange saturation transfer (CEST) combined were significantly different between groups (p < 0.01). Further, the T₂ relaxation of the semisolid macromolecular pool (T_2,B), a parameter specific to MT, was found to be significantly different (p < 0.01). Also significantly different were the rNOE contributions associated with methine groups at -0.9 ppm with a saturation B₁ of 0.5 µT (p < 0.01) and with other aliphatic groups at -3.3 ppm with 0.5 and 2 µT (both p < 0.05). Independently, using a live-cell metabolic assay, normal cells were found to have a greater metabolic rate than radioresistant ones. Thus, MRI provides a novel, in vivo method to quantify the metabolic rate of tumours and predict their radiosensitivity.

Long non-coding RNA XIST predicts worse prognosis in digestive system tumors: a systemic review and meta-analysis

Increasing studies are indicating that long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is associated with the prognosis of cancer patients. However, the results have been disputed. Therefore, we aimed to further explore the prognostic value and clinical significance of XIST in various types of cancers. Then, we focussed our research on the comparison of the predictive value of XIST between digestive system tumors and non-digestive system tumors. We performed a systematic search by looking up PubMed, Embase, Cochrane Library, Web of Science, and Medline (up to 3 January 2018). Fifteen studies which matched our inclusion criteria with a total of 920 patients for overall survival and 867 patients for clinicopathological characteristics were included in this meta-analysis. Pooled hazard ratios (HR) and odds ratios (ORs) with their corresponding 95% confidence intervals (95% CIs) were calculated to summarize the effects. Our results suggested that high expression levels of XIST were associated with unfavorable overall survival in cancer patients (pooled HR = 1.81, 95% CI: 1.45-2.26). Additionally, we found that XIST was more valuable in digestive system tumors (pooled HR = 2.24, 95% CI: 1.73-2.92) than in non-digestive system tumors (pooled HR = 1.22, 95% CI: 0.60-2.45). Furthermore, elevated expression levels of XIST were connected with distant metastasis and tumor stage. XIST was correlated with poor prognosis, which suggested that XIST might serve as a novel predictive biomarker for cancer patients, especially for patients of digestive system tumors.

The use of long non-coding RNAs as prognostic biomarkers and therapeutic targets in prostate cancer

Prostate cancer is the most common cancer in men and the second leading cause of cancer-related deaths. The most used biomarker to detect prostate cancer is Prostate Specific Antigen (PSA), whose levels are measured in serum. However, it has been recently established that molecular markers of cancer should not be based solely on genes and proteins but should also reflect other genomic traits; long non-coding RNAs (lncRNAs) serve this purpose. lncRNAs are transcripts of >200 bases that do not encode proteins and that have been shown to display abnormal expression profiles in different types of cancer. Experimental studies have highlighted lncRNAs as potential biomarkers for prognoses and treatments in patients with different types of cancer, including prostate cancer, where the PCA3 lncRNA is currently used as a diagnostic tool and management strategy. With the development of genomic technologies, particularly next-generation sequencing (NGS), several other lncRNAs have been linked to prostate cancer and are currently under validation for their medical use. In this review, we will discuss different strategies for the discovery of novel lncRNAs that can be evaluated as prognostic biomarkers, the clinical impact of these lncRNAs and how lncRNAs can be used as potential therapeutic targets.

LncRNAs regulate the cytoskeleton and related Rho/ROCK signaling in cancer metastasis

Some of the key steps in cancer metastasis are the migration and invasion of tumor cells; these processes require rearrangement of the cytoskeleton. Actin filaments, microtubules, and intermediate filaments involved in the formation of cytoskeletal structures, such as stress fibers and pseudopodia, promote the invasion and metastasis of tumor cells. Therefore, it is important to explore the mechanisms underlying cytoskeletal regulation. The ras homolog family (Rho) and Rho-associated coiled-coil containing protein serine/threonine kinase (ROCK) signaling pathway is involved in the regulation of the cytoskeleton. Moreover, long noncoding RNAs (lncRNAs) have essential roles in tumor migration and guide gene regulation during cancer progression. LncRNAs can regulate the cytoskeleton directly or may influence the cytoskeleton via Rho/ROCK signaling during tumor migration. In this review, we focus on the regulatory association between lncRNAs and the cytoskeleton and discuss the pathways and mechanisms involved in the regulation of cancer metastasis.