Overexpression of long non-coding RNA LOC400891 promotes tumor progression and poor prognosis in prostate cancer

Molecular Mechanisms of Prostate Cancer Development in the Precision Medicine Era: A Comprehensive Review

The progression of prostate cancer (PCa) relies on the activation of the androgen receptor (AR) by androgens. Despite efforts to block this pathway through androgen deprivation therapy, resistance can occur through several mechanisms, including the abnormal activation of AR, resulting in castration-resistant PCa following the introduction of treatment. Mutations, amplifications, and splicing variants in AR-related genes have garnered attention in this regard. Furthermore, recent large-scale next-generation sequencing analysis has revealed the critical roles of AR and AR-related genes, as well as the DNA repair, PI3K, and cell cycle pathways, in the onset and progression of PCa. Moreover, research on epigenomics and microRNA has increasingly become popular; however, it has not translated into the development of effective therapeutic strategies. Additionally, treatments targeting homologous recombination repair mutations and the PI3K/Akt pathway have been developed and are increasingly accessible, and multiple clinical trials have investigated the efficacy of immune checkpoint inhibitors. In this comprehensive review, we outline the status of PCa research in genomics and briefly explore potential future developments in the field of epigenetic modifications and microRNAs.

Signaling Pathways and Targeted Therapies for Stem Cells in Prostate Cancer

Prostate cancer (PCa) is one of the most frequently occurring cancers among men, and the current statistics show that it is the second leading cause of cancer-related deaths among men. Over the years, research in PCa treatment and therapies has made many advances. Despite these efforts, the standardized therapies such as radiation, chemotherapy, hormonal therapy and surgery are not considered completely effective in treating advanced and metastatic PCa. In most situations, fast-dividing tumor cells are targeted, leaving behind relatively slowly dividing, chemoresistant cells known as cancer stem cells. Therefore, following the seemingly successful treatments, the lingering quiescent cancer stem cells are able to renew themselves, undergo differentiation into mature tumor cells, and sufficiently reinitiate the disease, leading to cancer relapse. Thus, prostate cancer stem cells (PCSCs) have been reported to play a vital role in controlling the dynamics of tumorigenesis, progression, and resistance to therapies in PCa. However, the complete knowledge on the mechanisms regulating the stemness of PCSCs is still unclear. Thus, studying the stemness of PCSCs will allow for the development of more effective cancer therapies due to the durable response, resulting in a reduction in recurrences of cancer. In this Review, we will specifically describe the molecular mechanisms responsible for regulating the stemness of PCSCs. Furthermore, current developments in stem cell-specific therapeutic approaches along with future prospects will also be discussed.

Long non-coding RNAs and their potential impact on diagnosis, prognosis, and therapy in prostate cancer: racial, ethnic, and geographical considerations

INTRODUCTION

Advances in high-throughput sequencing have greatly advanced our understanding of long non-coding RNAs (lncRNAs) in a relatively short period of time. This has expanded our knowledge of cancer, particularly how lncRNAs drive many important cancer phenotypes via their regulation of gene expression.

AREAS COVERED

Men of African descent are disproportionately affected by PC in terms of incidence, morbidity, and mortality. LncRNAs could serve as biomarkers to differentiate low-risk from high-risk diseases. Additionally, they may represent therapeutic targets for advanced and castrate-resistant cancer. We review current research surrounding lncRNAs and their association with PC. We discuss how lncRNAs can provide new insights and diagnostic biomarkers for African American men. Finally, we review advances in computational approaches that predict the regulatory effects of lncRNAs in cancer.

EXPERT OPINION

PC diagnostic biomarkers that offer high specificity and sensitivity are urgently needed. PC specific lncRNAs are compelling as diagnostic biomarkers owing to their high tissue and tumor specificity and presence in bodily fluids. Recent studies indicate that PCA3 clinical utility might be restricted to men of European descent. Further work is required to develop lncRNA biomarkers tailored for men of African descent.

LOC100996425 acts as a promoter in prostate cancer by mediating hepatocyte nuclear factor 4A and the AMPK/mTOR pathway

The involvement of long non-coding RNAs (lncRNAs), differentially expressed genes and signals in prostate cancer (PCa) continues to be a subject of investigation. This study determined effects of LOC100996425 on human PCa by targeting hepatocyte nuclear factor 4A (HNF4A) via the AMPK/mTOR pathway. PCa and adjacent normal tissues were obtained to characterize expression pattern of LOC100996425, HNF4A and the AMPK/mTOR pathway-related genes. Then, the target gene of LOC100996425 was determined with lncRNA target prediction website and further verification was obtained through luciferase assay and ribonucleoprotein immunoprecipitation. After that, PCa cells were introduced with LOC100996425, HNF4A, siLOC100996425 or siHNF4A to explore the specific significance of LOC100996425 and HNF4A in PCa. The mechanism associated with AMPK/mTOR pathway was investigated using AMPK inhibitor or activator. LOC100996425 was up-regulated, while HNF4A was down-regulated in the PCa tissues. HNF4A was a target gene of LOC100996425. PCa cells transfected with either siLOC100996425 or HNF4A displayed reduced rates of PCa cell proliferation and migration while elevating cell apoptosis. HNF4A overexpression reversed the promotive effect of LOC100996425 overexpression on PCa. The activation of AMPK pathway involved in the cancer progression mediated by LOC100996425. Down-regulation of LOC100996425 retards progression of PCa through HNF4A-mediated AMPK/mTOR pathway.

Functional roles of lncRNAs in the pathogenesis and progression of cancer

Long noncoding RNAs (lncRNAs) act as regulators of gene expression and pivotal transcriptional regulators in cancer cells via diverse mechanisms. lncRNAs involves a variety of pathological and biological activities, such as apoptosis, cell proliferation, metastasis, and invasion. By using microarray and RNA sequencing, it was identified that dysregulation of lncRNAs affects the tumorigenesis process. Taken together, these lncRNAs are putative biomarker and therapeutic target in human malignancies. In this review, I discuss the latest finding regarding the dysregulation of some important lncRNAs and their diverse mechanisms of these lncRNAs in the pathogenesis and progression of certain cancers; also, I summarize the possible roles of lncRNAs in clinical application for diagnosis and prognosis of cancer.

Unraveling the dark matter, long non-coding RNAs, in male reproductive diseases: A narrative review

Recent advances in human transcriptome have revealed the fundamental and functional roles of long non-coding RNA in the susceptibility to diverse diseases and pathological conditions. They participate in wide range of biological processes such as the modulating of chromatin structure, transcription, translation, and post-translation modification. In addition, based on their unique expression profiles and their association with clinical abnormalities such as those of related to male reproductive diseases, they can be used to develop therapeutic methods and biomarkers for screening of the diseases. In this study, we will review the identified lncRNAs and their molecular functions in the pathogenesis of male reproductive diseases such as prostate cancer, benign prostatic hyperplasia, prostatitis, testicular cancer, varicocele, and sperm abnormalities.

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.

A comprehensive review of the role of long non-coding RNAs in organs with an endocrine function

Long non-coding RNAs (lncRNAs) are transcripts with sizes larger than 200 nucleotides and no/ small open reading frame that cannot produce functional proteins. The number of these transcripts surpasses the number of coding genes. LncRNAs regulate many aspects of cell functions such as proliferation, cell cycle transition and differentiation; so their dysregulation has pervasive effects on cell phenotype. Increasing numbers of these transcripts have been shown to participate in the pathogenesis of cancer. In the current review, we summarize recent findings regarding the role of lncRNAs in tumors originated from organs which have an endocrine function. We mostly focused on adrenal, pancreas and pituitary gland as prototypes of these organs. Moreover, we presented the obtained data of the role of lncRNAs in prostate, ovarian and testicular cancers. Recent data highly supports the role of lncRNAs in the pathogenesis of cancers originated from these organs. Moreover, certain genomic loci within lncRNAs have been shown to be associated with risk of these cancers. Diagnostic and prognostic role of some lncRNAs in these cancers have been evaluated recently. Taken together, lncRNAs are putative biomarkers for cancers originated from organs which have an endocrine function.

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.

A novel androgen-reduced prostate-specific lncRNA, PSLNR, inhibits prostate-cancer progression in part by regulating the p53-dependent pathway

BACKGROUND

Prostate cancer (PCa) is one of the most common cancers in males in China. Long noncoding RNAs (lncRNAs) reportedly play crucial roles in human cancer progression in many studies. However, the molecular mechanisms underlying PCa progression remain unclear.

MATERIALS AND METHODS

We investigated the lncRNA transcriptome using publicly available RNA-sequencing data to identify prostate-specific lncRNAs. Then, the chromatin immunoprecipitation (ChIP) assay identified lncRNA with a direct binding to androgen receptor (AR), hereafter denoted as PSLNR. Quantitative real-time polymerase chain reaction analysis and Western blot analysis were performed to detect the expression of p53 signaling-related genes after overexpression PSLNR. The effects of overexpression of PSLNR on cell proliferation, cell cycle, and cell apoptosis were assessed by using CCK-8 and flow cytometric analysis. We then detected the expression of PSLNR in tissues.

RESULT

We reported a novel androgen-reduced prostate-specific lncRNA, PSLNR, that inhibited PCa progression via the p53-dependent pathway. By analyzing the NOCODE data set, we reported that PSLNR was specifically expressed in the prostate, suggesting the potential of PSLNR as a biomarker for PCa treatment. The AR pathway was also confirmed to be an upstream regulation signaling pathway of PSLNR by transcriptionally regulating its expression in androgen-dependent PCa cells. PSLNR also significantly inhibited PCa proliferation by inducing cell apoptosis in a p53-dependent manner. Thus, PSLNR may be a candidate diagnosis and therapeutic target for PCa.

CONCLUSIONS

Our study revealed for the first time a novel androgen-reduced prostate-specific lncRNA, PSLNR, which inhibited PCa progression via the p53-dependent pathway, suggesting that PSLNR may be a candidate diagnosis and therapeutic target for PCa.

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.

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.

Carcinogenesis in prostate cancer: The role of long non-coding RNAs

LncRNAs appear to play a considerable role in tumourigenesis through regulating key processes in cancer cells such as proliferative signalling, replicative immortality, invasion and metastasis, evasion of growth suppressors, induction of angiogenesis and resistance to apoptosis. LncRNAs have been reported to play a role in prostate cancer, particularly in regulating the androgen receptor signalling pathway. In this review article, we summarise the role of 34 lncRNAs in prostate cancer with a particular focus on their role in the androgen receptor signalling pathway and the epithelial to mesenchymal transition pathway.

The gain and loss of long noncoding RNA associated-competing endogenous RNAs in prostate cancer

Prostate cancer (PC) is one of the most common solid tumors in men. However, the molecular mechanism of PC remains unclear. Numerous studies have demonstrated that long noncoding RNA (lncRNA) can act as microRNA (miRNA) sponge, one type of competing endogenous RNAs (ceRNAs), which offers a novel viewpoint to elucidate the mechanisms of PC. Here, we proposed an integrative systems biology approach to infer the gain and loss of ceRNAs in PC. First, we re-annotated exon microarray data to obtain lncRNA expression profiles of PC. Second, by integrating mRNA and miRNA expression, as well as miRNA targets, we constructed lncRNA-miRNA-mRNA ceRNA networks in cancer and normal samples. The lncRNAs in these two ceRNA networks tended to have a longer transcript length and cover more exons than the lncRNAs not involved in ceRNA networks. Next, we further extracted the gain and loss ceRNA networks in PC. We found that the gain ceRNAs in PC participated in cell cycle, and the loss ceRNAs in PC were associated with metabolism. We also identified potential prognostic ceRNA pairs such as MALAT1-EGR2 and MEG3-AQP3. Finally, we inferred a novel mechanism of known drugs, such as cisplatin, for the treatment of PC through gain and loss ceRNA networks. The potential drugs such as 1,2,6-tri-O-galloyl-beta-D-glucopyranose (TGGP) could modulate lncRNA-mRNA competing relationships, which may uncover new strategy for treating PC. In summary, we systematically investigated the gain and loss of ceRNAs in PC, which may prove useful for identifying potential biomarkers and therapeutics for PC.

Long Non-coding RNAs in Prostate Cancer with Emphasis on Second Chromosome Locus Associated with Prostate-1 Expression

Long non-coding RNAs (lncRNAs) are a class of RNA with transcripts longer than 200 nucleotides that lack functional open reading frames. They play various roles in human carcinoma, such as dysregulating gene expression in prostate cancer (PCa), which results in cancer initiation, development, and progression. The non-coding RNA SChLAP1 (second chromosome locus associated with prostate-1) is highly expressed in approximately 25% of PCas with higher prevalence in metastatic compared to localized PCa. Its expression is detectable non-invasively in PCa patient urine samples. Experimental data suggest that targeting SChLAP1 may represent a novel therapeutic application in PCa. This contribution focuses on the role of lncRNAs SChLAP1 expression in PCa diagnosis and prognosis.

The prognostic value of abnormally expressed lncRNAs in prostatic carcinoma: A systematic review and meta-analysis

BACKGROUND

Several long noncoding RNAs (lncRNAs) are abnormally expressed in prostate cancer (PCa), suggesting that they could serve as novel prognostic markers. The current meta-analysis was undertaken to better define the prognostic value of various lncRNAs in PCa.

METHODS

The PubMed, Embase, Medline, and Cochrane Library databases were systematically searched up to February 19, 2017, to retrieve eligible articles. Outcomes analyzed were biochemical recurrence-free survival (BRFS), overall survival (OS), metastasis-free survival (MFS), and prostate cancer-specific survival (PCSS). Pooled hazard ratios (HRs) and 95% confidence intervals (95%CIs) were calculated using fixed-effects or random-effects models.

RESULTS

A total of 10 studies, evaluating 11 PCa-related lncRNAs, were included in the meta-analysis. Pooled results indicate that the abnormal expression of candidate lncRNAs in PCa samples predicted poor BRFS (HR: 1.67, 95%CI: 1.37-2.04, P < .05), without significant heterogeneity among studies (I = 44%, P = .06). Low PCAT14 expression was negatively associated with OS (HR: 0.66, 95%CI: 0.54-0.79, P < .05), MFS (HR: 0.59, 95%CI: 0.48-0.72, P < .05), and PCSS (HR: 0.50, 95%CI: 0.38-0.66, P < .05). Again, there was no significant heterogeneity among studies. The robustness of our results was confirmed by sensitivity and publication bias analyses.

CONCLUSION

We conclude that expression analysis of selected lncRNAs may be of prognostic value in PCa patients.

The long non-coding RNA AK023948 enhances tumor progression in hepatocellular carcinoma

The long non-coding RNAs (lncRNAs) have been demonstrated to play pivotal roles in a broad range of processes including tumor biology. However, the exact contributions of lncRNAs to hepatocellular carcinoma (HCC) remain poorly defined. In current study, we have unraveled a novel function of AK023948 in HCC. We found that AK023948 was substantially upregulated in tumor tissues. Meanwhile, higher AK023948 expression correlated with poor survival. Upregulation of AK023948 expression can promote HepG2 and Hep3B proliferation and invasion in in vitro experiments. Furthermore, AK023948 also decreased tumor growth in vivo. The tumorigenic role of AK023948 was partially ascribed to PI3K/Akt/mTOR signaling and AK023948 knockdown decreased pathway activation and tumor growth. These data collectively suggest an oncogenic role for AK023948 and may provide potential insight into therapeutic intervention.

The prognostic value of long noncoding RNAs in prostate cancer: a systematic review and meta-analysis

The abnormally expressed LncRNAs played irreplaceable roles in the prognosis of prostate cancer (PCa). Therefore, we conducted this systematic review and meta-analysis to summarize the association between the expression of LncRNAs, prognosis and clinicopathology of PCa. 18 eligible studies were recruited into our analysis, including 18 on prognosis and 9 on clinicopathological features. Results indicated that aberrant expression of LncRNAs was significantly associated with biochemical recurrence-free survival (BCR-FS) (HR = 1.55, 95%CI: 1.01-2.37, P < 0.05), recurrence free survival (RSF) (HR = 3.07, 95%CI: 1.07-8.86, P < 0.05) and progression free survival (PFS) (HR = 2.34, 95%CI: 1.94-2.83, P < 0.001) in PCa patients. LncRNAs expression level was correlated with several vital clinical features, like tumor size (HR = 0.52, 95%CI: 0.28-0.95, P = 0.03), distance metastasis (HR = 4.55, 95%CI: 2.26-9.15, P < 0.0001) and histological grade (HR = 6.23, 95% CI: 3.29-11.82, P < 0.00001). Besides, down-regulation of PCAT14 was associated with the prognosis of PCa [over survival (HR = 0.77, 95%CI: 0.63-0.95, P = 0.01), BCR-FS (HR = 0.61, 95%CI: 0.48-0.79, P = 0.0001), prostate cancer-specific survival (HR = 0.64, 95%CI: 0.48-0.85, P = 0.002) and metastasis-free survival (HR = 0.61, 95%CI: 0.50-0.74, P < 0.00001)]. And, the increased SChLAP1 expression could imply the worse BCR-FS (HR = 2.54, 95%CI: 1.82-3.56, P < 0.00001) and correlate with Gleason score (< 7 vs ≥ 7) (OR = 4.11, 95% CI: 1.94-8.70, P = 0.0002). Conclusively, our present work demonstrated that LncRNAs transcription level might be potential prognostic markers in PCa.

Long noncoding RNA LINC01296 is associated with poor prognosis in prostate cancer and promotes cancer-cell proliferation and metastasis

Background/purpose

Long noncoding RNAs (lncRNAs) have emerged as important regulators and biomarkers of tumor development and progression. This study investigated the clinical significance, biological functions, and underlying mechanisms of long intergenic non-protein-coding RNA 1296 (LINC01296) in prostate cancer.

Materials and methods

LINC01296 expression in prostate cancer tissues and cell lines was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The correlation between LINC01296 expression and clinicopathologic characteristics of prostate cancer was analyzed using Kaplan–Meier analysis and the Cox proportional-hazard model. Small interfering RNA was used to suppress LINC01296, and knockdown efficiency was examined by qRT-PCR. Cell Counting Kit 8 assay, colony-formation assay, migration and invasion assays, and Western blot assay were used to explore the role of LINC01296 in tumor progression further.

Results

LINC01296-expression level was higher in prostate cancer tissues and prostate cancer cells than in adjacent nontumor tissues and immortalized normal prostate stromal WPMY1 cells. LINC01296 expression was correlated with preoperative prostate specific antigen (P=0.002), lymph-node metastasis (P=0.035), Gleason score (P<0.001), and tumor stage (P=0.036). Patients with higher LINC01296 expression displayed advanced clinical features and shorter biochemical recurrence-free survival time than those with lower LINC01296 expression. Multivariate analysis showed that LINC01296 expression was an independent predictor of biochemical recurrence-free survival in prostate cancer. Additionally, LINC01296 knockdown inhibited prostate cancer-cell proliferation, migration, and invasion, demonstrated in an in vitro study involving regulation of PI3K–Akt–mTOR signaling and epithelial–mesenchymal transition.

Conclusion

The results demonstrated that LINC01296 is a novel molecule involved in prostate cancer development and progression, and thus is a potential biomarker of prognosis.

Long Non-Coding RNA as Potential Biomarker for Prostate Cancer: Is It Making a Difference?

Whole genome transcriptomic analyses have identified numerous long non-coding RNA (lncRNA) transcripts that are increasingly implicated in cancer biology. LncRNAs are found to promote essential cancer cell functions such as proliferation, invasion, and metastasis, with the potential to serve as novel biomarkers of various cancers and to further reveal uncharacterized aspects of tumor biology. However, the biological and molecular mechanisms as well as the clinical applications of lncRNAs in diverse diseases are not completely understood, and remain to be fully explored. LncRNAs may be critical players and regulators in prostate cancer carcinogenesis and progression, and could serve as potential biomarkers for prostate cancer. This review focuses on lncRNA biomarkers that are already available for clinical use and provides an overview of lncRNA biomarkers that are under investigation for clinical development in prostate cancer.