Prognostic value of abnormally expressed lncRNAs in ovarian carcinoma: a systematic review and meta-analysis

Identification of potential novel N6-methyladenosine effector-related lncRNA biomarkers for serous ovarian carcinoma: a machine learning-based exploration in the framework of 3P medicine

Background

Serous ovarian carcinoma (SOC) is considered the most lethal gynecological malignancy. The current lack of reliable prognostic biomarkers for SOC reduces the efficacy of predictive, preventive, and personalized medicine (PPPM/3PM) in patients with SOC, leading to unsatisfactory therapeutic outcomes. N6-methyladenosine (m6A) modification-associated long noncoding RNAs (lncRNAs) are effective predictors of SOC. In this study, an effective risk prediction model for SOC was constructed based on m6A modification-associated lncRNAs.

Methods

Transcriptomic data and clinical information of patients with SOC were downloaded from The Cancer Genome Atlas. Candidate lncRNAs were identified using univariate and multivariate and least absolute shrinkage and selection operator-penalized Cox regression analyses. The molecular mechanisms of m6A effector-related lncRNAs were explored via Gene Ontology, pathway analysis, gene set enrichment analysis, and gene set variation analysis (GSVA). The extent of immune cell infiltration was assessed using various algorithms, including CIBERSORT, Microenvironment Cell Populations counter, xCell, European Prospective Investigation into Cancer and Nutrition, and GSVA. The calcPhenotype algorithm was used to predict responses to the drugs commonly used in ovarian carcinoma therapy. In vitro experiments, such as migration and invasion Transwell assays, wound healing assays, and dot blot assays, were conducted to elucidate the functional roles of candidate lncRNAs.

Results

Six m6A effector-related lncRNAs that were markedly associated with prognosis were used to establish an m6A effector-related lncRNA risk model (m6A-LRM) for SOC. Immune microenvironment analysis suggested that the high-risk group exhibited a proinflammatory state and displayed increased sensitivity to immunotherapy. A nomogram was constructed with the m6A effector-related lncRNAs to assess the prognostic value of the model. Sixteen drugs potentially targeting m6A effector-related lncRNAs were identified. Furthermore, we developed an online web application for clinicians and researchers (https://leley.shinyapps.io/OC_m6A_lnc/). Overexpression of the lncRNA RP11-508M8.1 promoted SOC cell migration and invasion. METTL3 is an upstream regulator of RP11-508M8.1. The preliminary regulatory axis METTL3/m6A/RP11-508M8.1/hsa-miR-1270/ARSD underlying SOC was identified via a combination of in vitro and bioinformatic analyses.

Conclusion

In this study, we propose an innovative prognostic risk model and provide novel insights into the mechanism underlying the role of m6A-related lncRNAs in SOC. Incorporating the m6A-LRM into PPPM may help identify high-risk patients and personalize treatment as early as possible.

Emerging RNA-Based Therapeutic and Diagnostic Options: Recent Advances and Future Challenges in Genitourinary Cancers

Renal cell carcinoma, bladder cancer, and prostate cancer are the most widespread genitourinary tumors. Their treatment and diagnosis have significantly evolved over recent years, due to an increasing understanding of oncogenic factors and the molecular mechanisms involved. Using sophisticated genome sequencing technologies, the non-coding RNAs, such as microRNAs, long non-coding RNAs, and circular RNAs, have all been implicated in the occurrence and progression of genitourinary cancers. Interestingly, DNA, protein, and RNA interactions with lncRNAs and other biological macromolecules drive some of these cancer phenotypes. Studies on the molecular mechanisms of lncRNAs have identified new functional markers that could be potentially useful as biomarkers for effective diagnosis and/or as targets for therapeutic intervention. This review focuses on the mechanisms underlying abnormal lncRNA expression in genitourinary tumors and discusses their role in diagnostics, prognosis, and treatment.

Mechanism Analysis of LINC00665 and Its Peptides CIP2A-BP in Hepatocellular Carcinoma

Background: More and more studies show that long non-coding RNAs (lncRNAs) have miniature open reading frames that can be translated into short peptides. Here, we identify the long non-coding gene LINC00665 and its short peptides (CIP2A-BP) in hepatocellular carcinoma (HCC) and explore how they contribute to HCC progression. Materials and methods: First, GSE101728 data were acquired through the Gene Expression Omnibus for identification of differentially expressed genes (DEGs), and gene set enrichment analysis (GSEA) was conducted to find enriched biological pathways. Then, further bioinformatics analysis was carried out on the screened long non-coding genes, and LINC00665 expression was detected in HCC and normal liver samples. The relations between LINC00665 expression, HCC prognosis, and clinical characteristics were studied. Receiver operating characteristic (ROC) analysis was also applied to verify the LINC00665 prediction in HCC prognosis. In addition, pertinent experiments on LINC00665 and CIP2A-BP were also carried out to explore their roles in the progression of HCC. Results: As a result, we screened out 332 DEGs in total, including 130 upregulated and 202 downregulated DEGs. These DEGs were mainly enriched in posttranscriptional regulation of gene expression, RNA processing, nucleolus, and gene silencing biological pathways. In addition, we found that LINC00665 was increased in HCC samples, which substantially indicated its poor prognosis. Compared with normal tissues, LINC00665 had higher expression in the pathological stages III and IV, tumor-free groups, people no more than 60 years old, and stages T3, T4, N0, N1, and M1. ROC curve indicated that the variable INC00665 had certain accuracy in predicting overall survival (OS). Moreover, in functional experiments, LINC00665 knockdown could significantly decrease HCC cell proliferation, migration, and invasion, while overexpressed CIP2A-BP could markedly increase HCC cell proliferation, invasion, and migration. Conclusion: Our findings not only disclose a unique mechanism by which CIP2A-BP encoded by LINC00665 promotes HCC carcinogenesis but suggest that these long non-coding genes and short peptides could be used as biomarkers for HCC diagnosis and prognosis and new targets for HCC therapy.

(In)Distinctive Role of Long Non-Coding RNAs in Common and Rare Ovarian Cancers

Rare ovarian cancers (ROCs) are OCs with an annual incidence of fewer than 6 cases per 100,000 women. They affect women of all ages, but due to their low incidence and the potential clinical inexperience in management, there can be a delay in diagnosis, leading to a poor prognosis. The underlying causes for these tumors are varied, but generally, the tumors arise due to alterations in gene/protein expression in cellular processes that regulate normal proliferation and its checkpoints. Dysregulation of the cellular processes that lead to cancer includes gene mutations, epimutations, non-coding RNA (ncRNA) regulation, posttranscriptional and posttranslational modifications. Long non-coding RNA (lncRNA) are defined as transcribed RNA molecules, more than 200 nucleotides in length which are not translated into proteins. They regulate gene expression through several mechanisms and therefore add another level of complexity to the regulatory mechanisms affecting tumor development. Since few studies have been performed on ROCs, in this review we summarize the mechanisms of action of lncRNA in OC, with an emphasis on ROCs.

Non-coding RNAs in melanoma: Biological functions and potential clinical applications

Malignant melanoma (MM) is a malignant tumor that originates from melanocytes and has a high mortality rate. Therefore, early diagnosis and treatment are very important for survival. So far, the exact molecular mechanism leading to the occurrence of melanoma, especially the molecular metastatic mechanism, remains largely unknown. Non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNA (circRNAs), have been investigated and found to play vital roles in regulating tumor occurrence and development, including melanoma. In this review, we summarize the progress of recent research on the effects of ncRNAs on melanoma and attempt to elucidate the role of ncRNAs as molecular markers or potential targets that will provide promising application perspectives on melanoma.

Comprehensive analysis of lncRNAs as biomarkers for diagnosis, prognosis, and treatment response in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common histological type of renal carcinoma and has a high recurrence rate and poor outcome. Accurate patient risk stratification based on genetic markers can help to identify the high-risk patient for early and further treatments and would promote patient survival. Long non-coding RNAs (lncRNAs) have attracted widespread attention as biomarkers for early diagnosis, treatment, and prognosis because of their high specificity and sensitivity. Here, we performed a systematic search in NCBI PubMed and found 44 lncRNAs as oncogenes, 18 lncRNAs as tumor suppressors, 199 lncRNAs as diagnostic biomarkers, 62 lncRNAs as prognostic biomarkers, and 3 lncRNAs as predictive biomarkers for ccRCC. We also comprehensively discuss the biological functions and molecular regulatory mechanisms of lncRNAs in ccRCC. Overall, the present study is a systemic analysis to assess the expression and clinical value of lncRNAs in ccRCC, and lncRNAs hold promise to be diagnostic, prognostic, and predictive biomarkers.

Mechanisms of Apoptosis-Related Long Non-coding RNAs in Ovarian Cancer

Ovarian cancer is a health-threatening malignancy of ovary in female reproductive systems and one of the most common gynecological malignancies worldwide. Due to rare early symptoms, ovarian cancers are often diagnosed at advanced stages and exhibit poor prognosis. Thus, efforts have been paid to develop alternative diagnostic and therapeutic strategies for the disease. Recent studies have presented that some long non-coding RNAs (lncRNAs) play roles in apoptosis of ovarian cancer cells through various mechanisms involved in the regulation of transcription factors, histone modification complexes, miRNAs, and protein stability. Because evasion of apoptosis in cancer cells facilitates to promote tumor progression and therapy resistance, apoptosis regulatory mechanisms of lncRNAs may be promising new targets in ovarian cancer. In this review, we introduce the recent findings in regard to the molecular mechanisms of apoptosis-related lncRNAs in ovarian cancer cells.

Development of a novel transcription factors-related prognostic signature for serous ovarian cancer

Growing evidence suggest that transcription factors (TFs) play vital roles in serous ovarian cancer (SOC). In the present study, TFs mRNA expression profiles of 564 SOC subjects in the TCGA database, and 70 SOC subjects in the GEO database were screened. A 17-TFs related prognostic signature was constructed using lasso cox regression and validated in the TCGA and GEO cohorts. Consensus clustering analysis was applied to establish a cluster model. The 17-TFs related prognostic signature, risk score and cluster models were effective at accurately distinguishing the overall survival of SOC. Analysis of genomic alterations were used to elaborate on the association between the 17-TFs related prognostic signature and genomic aberrations. The GSEA assay results suggested that there was a significant difference in the inflammatory and immune response pathways between the high-risk and low-risk score groups. The potential immune infiltration, immunotherapy, and chemotherapy responses were analyzed due to the significant difference in the regulation of lymphocyte migration and T cell-mediated cytotoxicity between the two groups. The results indicated that patients with low-risk score were more likely to respond anti-PD-1, etoposide, paclitaxel, and veliparib but not to gemcitabine, doxorubicin, docetaxel, and cisplatin. Also, the prognostic nomogram model revealed that the risk score was a good prognostic indicator for SOC patients. In conclusion, we explored the prognostic values of TFs in SOC and developed a 17-TFs related prognostic signature to predict the survival of SOC patients.

The role of altered long noncoding RNAs in overall survival of ovarian cancer: A systematic review and meta-analysis

In recent years, tremendous research efforts have been focused on investigating the effect of dysregulation of lncRNAs on cancer progression, most of which confirm a positive link. This inspired us to conduct the present meta-analysis to explore whether aberrant expression of multiple lncRNAs has a role in patients' outcome in ovarian cancer. This comprehensive meta-analysis pertains to the evaluation of association between dysregulated lncRNAs expression level with eventual outcome and clinicopathological characteristics of ovarian cancer patients. We systematically searched PubMed, Web of Science, and Scopus to find all eligible articles. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) for overall survival, disease-free survival and progression-free survival were measured with a fixed or random effects model. A total of 34 studies were included in the meta-analysis. Dysregulation of lncRNAs were contributed to shorter overall survival (34 studies, 1180 patients HR = 2.12, 95% CI: 1.73 ± 2.60, random-effects) in ovarian cancer. Furthermore, altered lncRNAs were also related to decreased progression-free survival (8 studies, 1180 patients HR: 1.88, 95% CI: (1.35-2.62) and disease-free survival (2 studies, 285 patients, HR: 6.07, 95% CI: 1.28-28.78) in this disease. Our analyses supported the robust prognostic significance of altered lncRNAs in ovarian cancer. However, more extended studies are encouraged to evaluate the clinical application potential of these lncRNAs in the prognosis evaluation of ovarian cancer.

Long non-coding RNAs in recurrent ovarian cancer: Theranostic perspectives

Nearly 70% of ovarian cancer (OC) patients experience recurrence within the first 2 years after initial treatment. Emerging evidence indicates that long non-coding RNAs (lncRNAs) play a pivotal role in the pathogenesis of OC progression, resistance to therapy and recurrent OC (ROC). Transcriptome profiling studies have reported differential expression patterns of lncRNAs in OC which are related to increased cell invasion, metastasis and drug resistance. In this review, we highlighted the roles of lncRNAs in OC progression and outlined the potential molecular mechanisms by which lncRNAs impact on ROC. Recent advances using lncRNAs as potential biomarkers for screening, detection, prediction, response to therapy and as therapeutic targets are discussed.

The Interplay between Long Noncoding RNAs and Proteins of the Epigenetic Machinery in Ovarian Cancer

Comprehensive large-scale sequencing and bioinformatics analyses have uncovered a myriad of cancer-associated long noncoding RNAs (lncRNAs). Aberrant expression of lncRNAs is associated with epigenetic reprogramming during tumor development and progression, mainly due to their ability to interact with DNA, RNA, or proteins to regulate gene expression. LncRNAs participate in the control of gene expression patterns during development and cell differentiation and can be cell and cancer type specific. In this review, we described the potential of lncRNAs for clinical applications in ovarian cancer (OC). OC is a complex and heterogeneous disease characterized by relapse, chemoresistance, and high mortality rates. Despite advances in diagnosis and treatment, no significant improvements in long-term survival were observed in OC patients. A set of lncRNAs was associated with survival and response to therapy in this malignancy. We manually curated databases and used bioinformatics tools to identify lncRNAs implicated in the epigenetic regulation, along with examples of direct interactions between the lncRNAs and proteins of the epigenetic machinery in OC. The resources and mechanisms presented herein can improve the understanding of OC biology and provide the basis for further investigations regarding the selection of novel biomarkers and therapeutic targets.

Back to the Future: Rethinking the Great Potential of lncRNAS for Optimizing Chemotherapeutic Response in Ovarian Cancer

Ovarian cancer (OC) is one of the most fatal cancers in women worldwide. Currently, platinum- and taxane-based chemotherapy is the mainstay for the treatment of OC. Yet, the emergence of chemoresistance results in therapeutic failure and significant relapse despite a consistent rate of primary response. Emerging evidence substantiates the potential role of lncRNAs in determining the response to standard chemotherapy in OC. The objective of this narrative review is to provide an integrated, synthesized overview of the current state of knowledge regarding the role of lncRNAs in the emergence of resistance to platinum- and taxane-based chemotherapy in OC. In addition, we sought to develop conceptual frameworks for harnessing the therapeutic potential of lncRNAs in strategies aimed at enhancing the chemotherapy response of OC. Furthermore, we offered significant new perspectives and insights on the interplay between lncRNAs and the molecular circuitries implicated in chemoresistance to determine their impacts on therapeutic response. Although this review summarizes robust data concerning the involvement of lncRNAs in the emergence of acquired resistance to platinum- and taxane-based chemotherapy in OC, effective approaches for translating these lncRNAs into clinical practice warrant further investigation.

Expression of RRBP1 in epithelial ovarian cancer and its clinical significance

Hematopoietic pre-B cell leukemia transcription factor (PBX)-interacting protein (RRBP1) has been shown to participate in various aspects of malignancies. The clinical significance of RRBP1 and its involvement in the epithelial ovarian cancer have yet to be studied. The aim of the present study was to investigate the expression of RRBP1 in epithelial ovarian cancer (EOC) and its relationship with clinical characteristics and prognosis. We evaluated the mRNA and protein expression levels of RRBP1 by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting (n=45). Immunohistochemistry and data analysis were used to examine the relationship between the expression level of RRBP1 and the clinicopathological features and prognosis of epithelial ovarian cancer. RRBP1 was highly expressed in EOC (P<0.001). The specimens were obtained from 108 patients undergoing surgery to treat epithelial ovarian cancer. RRBP1 expression was obviously related to Federation International of Gynecologie and Obstetrigue (FIGO) stage (P<0.001), histological grade (P=0.021), histological type (P=0.004), and lymph node metastasis (P=0.012) but was not related to patient age (P=0.385) or preoperative carbohydrate antigen125 (CA125) level (P=0.238). Univariate analysis showed that the prognosis of the epithelial ovarian cancer patients was related to the age of the patients, the FIGO stage, and the expression level of RRBP1 (P<0.05). Patients with higher RRBP1 expression had significantly worse overall survival (OS) (P=0.003) and disease-free survival (DFS) (P<0.001). Multivariate survival analysis proved that RRBP1 was an independent predictor of OS (P=0.003) and DFS (P<0.001). RRBP1 plays an important role in predicting the prognosis of EOC. These results show that RRBP1 is a potential target for the treatment of epithelial ovarian cancer.

Low Expression of Protocadherin-8 Promotes the Progression of Ovarian Cancer

OBJECTIVE

Ovarian cancer (OC) is the second most lethal gynecological cancer among women throughout the world. Protocadherin-8 (PCDH8) could function as a candidate tumor suppressor. However, the link between PCDH8 and OC development is poorly understood.

MATERIALS AND METHODS

A total of 68 OC patients were retrospectively enrolled. Clinical information was collected and cancer tissues were used for tissue microarray. The PCDH8 expression was determined on tissue microarray by immunohistochemical staining, and PCDH8 protein was detected in cancer tissues and adjacent tissue by western blotting. Human OC cell lines (SKOV-3 and OVCAR-3) were used to assess the effects of PCDH8 overexpression by western blot and real-time PCR analysis. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell proliferation assay, wound healing migration assay, colony formation assay and invasion assays were performed to assess the influence of PCDH8 on cell function. Cells with Luc-nonspecific Lentiviral or Luc-Lentiviral with PCDH8 gene were subcutaneously injected into nude mice to observe the effect of PCDH8 gene on tumor growth. Bioluminescence imaging was used to observe tumor volume.

RESULTS

We found a low expression of PCDH8 in OC tissues versus the corresponding adjacent tissue. The PCDH8 expression, International Federation of Gynecology and Obstetrics stage, metastasis and recurrence were the independent prognostic factors for over-all survival by multivariate analyses. Furthermore, the patients with recurrence presented a low level of PCDH8 in OC tissues, and patients with advanced tumor stage also had a low PCDH8 expression. Importantly, the low expression of PCDH8 in OC tissues had a poor prognosis with a low overall survival rate. Overexpression of PCDH8 could inhibit OC cell growth/proliferation, migration, invasion, and colony formation in vitro. In vivo experiments also proved that overexpression of PCDH8 could inhibit OC cell growth/proliferation.

CONCLUSIONS

Protocadherin-8 might be considered as a candidate tumor suppressor and play a crucial role in the progression of OC.

BC200 RNA: An Emerging Therapeutic Target and Diagnostic Marker for Human Cancer

One of the most interesting findings from genome-wide expression analysis is that a considerable amount of noncoding RNA (ncRNA) is present in the cell. Recent studies have identified diverse biological functions of ncRNAs, which are expressed in a much wider array of forms than proteins. Certain ncRNAs associated with diseases, in particular, have attracted research attention as novel therapeutic targets and diagnostic markers. BC200 RNA, a 200-nucleotide ncRNA originally identified as a neuron-specific transcript, is abnormally over-expressed in several types of cancer tissue. A number of recent studies have suggested mechanisms by which abnormal expression of BC200 RNA contributes to the development of cancer. In this article, we first provide a brief review of a recent progress in identifying functions of BC200 RNA in cancer cells, and then offer examples of other ncRNAs as new therapeutic targets and diagnostic markers for human cancer. Finally, we discuss future directions of studies on BC200 RNA for new cancer treatments.

Prediction of candidate RNA signatures for recurrent ovarian cancer prognosis by the construction of an integrated competing endogenous RNA network

Tumor recurrence hinders treatment of ovarian cancer. The present study aimed to identify potential biomarkers for ovarian cancer recurrence prognosis and explore relevant mechanisms. RNA-sequencing of data from the TCGA database and GSE17260 dataset was carried out. Samples of the data were grouped according to tumor recurrence information. Following data normalization, differentially expressed genes/micro RNAs (miRNAs)/long non-coding (lncRNAs) (DEGs/DEMs/DELs) were selected between recurrent and non-recurrent samples. Their correlations with clinical information were analyzed to identify prognostic RNAs. A support vector machine classifier was used to find the optimal gene set with feature genes that could conclusively distinguish different samples. A protein-protein interaction (PPI) network was established for DEGs using relevant protein databases. An integrated ‘lncRNA/miRNA/mRNA’ competing endogenous RNA (ceRNA) network was constructed to reveal potential regulatory relationships among different RNAs. We identified 36 feature genes (e.g. TP53 and RBPMS) for the classification of recurrent and non-recurrent ovarian cancer samples. Prediction with this gene set had a high accuracy (91.8%). Three DELs (WT1-AS, NBR2 and ZNF883) were highly associated with the prognosis of recurrent ovarian cancer. Predominant DEMs with their targets were hsa-miR-375 (target: RBPMS), hsa-miR-141 (target: RBPMS), and hsa-miR-27b (target: TP53). Highlighted interactions in the ceRNA network were ‘WT1-AS-hsa-miR-375-RBPMS’ and ‘WT1-AS-hsa-miR-27b-TP53’. TP53, RBPMS, hsa-miR-375, hsa-miR-141, hsa-miR-27b, and WT1-AS may be biomarkers for recurrent ovarian cancer. The interactions of ‘WT1-AS-hsa-miR-375-RBPMS’ and ‘WT1-AS-hsa-miR-27b-TP53’ may be potential regulatory mechanisms during cancer recurrence.

Altered long noncoding RNAs and survival outcomes in ovarian cancer: A systematic review and meta-analysis (PRISMA Compliant)

BACKGROUND

Previous studies investigating the association between altered long noncoding RNAs (lncRNAs) and survival outcomes in ovarian cancer have obtained controversial results. To comprehensively evaluate the association, we conducted a systematic review and meta-analysis of the studies published on the subject.

METHODS

We performed a systematic search using the databases of the Cochrane Central Register of Controlled Trials, PubMed, and Embase to find all relevant articles from inception to May 7, 2017. Studies that evaluated the association between 1 specific lncRNA and survival outcomes in ovarian cancer were included. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) for overall survival, progression-free survival, and disease-free survival were calculated with a fixed-effects or random-effects model.

RESULTS

A total of 15 studies involving 1333 patients with ovarian cancer were included in this meta-analysis. Altered lncRNAs were associated with decreased overall survival (HR: 2.29, 95% CI: 1.92-2.75) without heterogeneity (I = 0.0%) in ovarian cancer. Altered lncRNAs were also associated with decreased progression-free survival (HR: 2.77, 95% CI: 1.00-7.62, I = 76.6%) and disease-free survival (HR: 2.59, 95% CI: 0.89-7.57, I = 62.9%) in ovarian cancer.

CONCLUSION

Our results supported the strong prognostic value of altered lncRNAs in ovarian cancer. Further large-scale studies should be carried out to verify the clinical applications of altered lncRNAs in the prognosis assessment of ovarian cancer.

The Impact of lncRNA Dysregulation on Clinicopathology and Survival of Breast Cancer: A Systematic Review and Meta-analysis

Dysregulation of multiple long non-coding RNAs (lncRNAs) was reported to play major roles in breast cancer (BC). Here we aimed to collect most of the relevant literature to assess the prognostic value of lncRNAs in BC. To this end, we systematically searched PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure (CNKI), and Wanfang to identify published articles on the associations of lncRNAs with clinicopathology and/or survival of BC. Via this searching, we identified 70 articles involving 9,307 BC patients and regarding 48 lncRNAs. The expression of 41 lncRNAs was related to one or more clinicopathological parameters of BC, including tumor size; lymph node metastasis; histological grade; TNM stage; and estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2) statuses (p < 0.05). Dysregulation of 28 lncRNAs was associated with overall survival, and abnormal expression of 9 lncRNAs was linked to disease-free survival. Furthermore, the expression level of 3 lncRNAs was correlated with metastasis-free survival, 3 lncRNAs with relapse-free survival, and 3 lncRNAs with progression-free survival. Our analysis showed that multiple lncRNAs were significantly associated with BC clinicopathology and survival. A large-scale study is needed to verify the prognostic value of these lncRNAs in BC.

The prognostic significance of long noncoding RNAs in bladder cancer: A meta-analysis

Introduction

Bladder cancer (BC) is one of the most common urologic malignancies and it is urgently needed to identify novel potential prognostic biomarkers for predicting prognosis and progression of patients with BC in clinical practice. Previous research has revealed that long noncoding RNAs (lncRNAs) played critical roles in BC, and may serve as novel potential prognostic biomarkers in patients with BC. Therefore, we conducted this meta-analysis to clarify the prognostic potential of lncRNAs in BC patients.

Methods

A comprehensive search was performed in PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI). According to the predefined exclusion and inclusion criteria, a total of 9 recently published articles comprising 13 lncRNAs and 666 BC patients were included into this meta-analysis. We analyzed the hazard ratios (HRs) and 95% confidence intervals (CIs) to determine the relationship between lncRNAs expression and survival outcomes. We also analyzed the odds ratio (ORs) and 95% confidence intervals (CIs) to assess the association between lncRNAs expression and clinicopathological characteristics, including histological grade, gender, multifocality, tumor size, and tumor stage.

Results

Our results revealed that high lncRNAs expression was associated with shorter overall survival in Asian BC patients (pooled HR = 2.32, 95% CI: 1.35–4.00, P = 0.002, random-effect). High lncRNAs expression levels were significantly associated with histological grade (G2-G3 vs. G1: OR = 3.857, 95%CI: 1.293–11.502, P = 0.015, random-effect).

Conclusions

In summary, this meta-analysis has demonstrated that lncRNAs could be used as potential prognostic markers for BC and high lncRNAs expression could predict poor prognosis among Asian BC patients.

Eukaryotic elongation factors 2 promotes tumor cell proliferation and correlates with poor prognosis in ovarian cancer

Eukaryotic elongation factors 2 (eEF2) plays an essential role in the GTP-dependent translocation of the ribosome along mRNA. Previous studies have shown that eEF2 is overexpressed in various tumors. However, little is known about the role of eEF2 in ovarian cancer. The aim of the present study is to examine the effect of eEF2 on ovarian cancer proliferation. We first measured eEF2 protein expression by western blot using six fresh ovarian cancer tissues from G1 to G3. The results showed that eEF2 expression gradually increased from G1 to G3. Additionally, eEF2 expression correlated significantly with grade (P = 0.045), FIGO stage (P = 0.035) and Ki67 (P < 0.05). Additionally, there was a significant positive association between eEF2 expression and Ki67 (r = 0.855). Cox's proportional hazards model also showed that eEF2 (P = 0.004) and Ki67 (P < 0.001) were an independent prognostic factor of overall survival in ovarian cancer patients. In vitro, after the release of ovarian cancer cell line (HO8910) from serum starvation, the expression of eEF2, cyclinD1 and PCNA was up-regulated. Moreover, silencing eEF2 in HO8910 cells decreased cell proliferation. Finally, we hypothesize that eEF2 may be activated in a positive feedback cycle through inactivation of eEF2K via the PI3K/Akt/mTOR pathway. These data provide novel insights into developing experimental therapies for ovarian cancer.

Non-coding RNAs: long non-coding RNAs and microRNAs in endocrine-related cancers

The human genome is 'pervasively transcribed' leading to a complex array of non-coding RNAs (ncRNAs) that far outnumber coding mRNAs. ncRNAs have regulatory roles in transcription and post-transcriptional processes as well numerous cellular functions that remain to be fully described. Best characterized of the 'expanding universe' of ncRNAs are the ~22 nucleotide microRNAs (miRNAs) that base-pair to target mRNA's 3' untranslated region within the RNA-induced silencing complex (RISC) and block translation and may stimulate mRNA transcript degradation. Long non-coding RNAs (lncRNAs) are classified as >200 nucleotides in length, but range up to several kb and are heterogeneous in genomic origin and function. lncRNAs fold into structures that interact with DNA, RNA and proteins to regulate chromatin dynamics, protein complex assembly, transcription, telomere biology and splicing. Some lncRNAs act as sponges for miRNAs and decoys for proteins. Nuclear-encoded lncRNAs can be taken up by mitochondria and lncRNAs are transcribed from mtDNA. Both miRNAs and lncRNAs are dysregulated in endocrine cancers. This review provides an overview on the current understanding of the regulation and function of selected lncRNAs and miRNAs, and their interaction, in endocrine-related cancers: breast, prostate, endometrial and thyroid.

Developing a genetic signature to predict drug response in ovarian cancer

There is a lack of personalized treatment options for women with recurrent platinum-resistant ovarian cancer. Outside of bevacizumab and a group of poly ADP-ribose polymerase inhibitors, few options are available to women that relapse. We propose that efficacious drug combinations can be determined via molecular characterization of ovarian tumors along with pre-established pharmacogenomic profiles of repurposed compounds. To that end, we selectively performed multiple two-drug combination treatments in ovarian cancer cell lines that included reactive oxygen species inducers and HSP90 inhibitors. This allowed us to select cell lines that exhibit disparate phenotypes of proliferative inhibition to a specific drug combination of auranofin and AUY922. We profiled altered mechanistic responses from these agents in both reactive oxygen species and HSP90 pathways, as well as investigated PRKCI and lncRNA expression in ovarian cancer cell line models. Generation of dual multi-gene panels implicated in resistance or sensitivity to this drug combination was produced using RNA sequencing data and the validity of the resistant signature was examined using high-density RT-qPCR. Finally, data mining for the prevalence of these signatures in a large-scale clinical study alluded to the prevalence of resistant genes in ovarian tumor biology. Our results demonstrate that high-throughput viability screens paired with reliable in silico data can promote the discovery of effective, personalized therapeutic options for a currently untreatable disease.

Expression of the long non-coding RNA HOTAIR as a prognostic factor in squamous cell carcinoma of the head and neck: a systematic review and meta-analysis

Introduction

Long noncoding RNAs (lncRNAs) are often dysregulated in cancer tissue and seem to play an important role in neoplastic processes. Recent studies have shown that the HOX transcript antisense intergenic RNA (HOTAIR) may play a role as a marker of prognosis in squamous cell carcinoma of the head and neck (SCCHN). The aim of this study was to perform a meta-analysis of studies focused on the prognostic role of HOTAIR in SCCHN.

Results

At the end of the selection process, four studies were considered eligible for inclusion in the meta-analysis, comprising a total of 271 patients. Meta-analysis revealed that high expression of HOTAIR was associated with poor overall survival (HR, 1.90; 95% CI: [1.42, 2.53]; p < 0,0001), advanced tumor stage (OR, 3.44; 95% CI: [1.84, 6.43]; p < 0,001) and lymph-node metastasis (OR, 3.31; 95% CI: [1.24, 8.79]; p = 0,02).

Materials and Methods

The literature search was performed in the following databases: PUBMED, SCOPUS, EMBASE and Web of Science, in order to find studies that met the inclusion criteria.

Conclusions

Findings from this systematic review and meta-analysis revealed that HOTAIR represents a potential biomarker of prognosis in patients with squamous cell carcinoma of the head and neck.

Prognostic role of long non-coding RNA TUG1 expression in various cancers: a meta-analysis

Several studies were conducted to explore the prognostic role of long non-coding RNA taurine upregulated gene 1 (lncRNA TUG1) expression in various cancers, with contradictory. This study aims to summarize the prognostic role of lncRNA TUG1 expression in various cancers. Embase, PubMed and Cochrane Library were completely retrieved. The cohort studies focusing on the prognostic role of lncRNA TUG1 expression in various cancers were eligible. The endpoints were overall survival (OS) and clinicopathological parameters. 9 studies involving a total of 1,078 patients were identified. The results showed that high lncRNA TUG1 expression was obviously associated with worse OS when compared to the low lncRNA TUG1 expression (HR = 1.37, 95% CI = 1.07–1.76, P = 0.01; I² = 85%). However, No distinct relationship was observed between the lncRNA TUG1 expression and age (OR = 0.99, 95% CI = 0.76–1.28, P = 0.92; I2 = 4%), gender (OR = 0.92, 95% CI = 0.70–1.22, P = 0.57; I² = 0%), diameter (OR = 0.83, 95% CI = 0.34–2.01, P = 0.67; I² = 85%), smoking (OR = 1.09, 95% CI = 0.37–3.21, P = 0.87; I² = 73%), TNM stage (OR = 0.60, 95% CI = 0.25–1.43, P = 0.25; I² = 86%) and lymph node metastasis (OR = 1.07, 95% CI = 0.47–2.45, P = 0.87; I² = 86%). In conclusion, it was revealed that high lncRNA TUG1 expression is an unfavorable predictor of OS in patients with cancers, and lncRNA TUG1 expression is a promising prognostic biomarker for various cancers.