Amplification and the clinical significance of circulating cell-free DNA of PVT1 in breast cancer

lncRNA PVT1: a novel oncogene in multiple cancers

Long noncoding RNAs are involved in epigenetic gene modification, including binding to the chromatin rearrangement complex in pre-transcriptional regulation and to gene promoters in gene expression regulation, as well as acting as microRNA sponges to control messenger RNA levels in post-transcriptional regulation. An increasing number of studies have found that long noncoding RNA plasmacytoma variant translocation 1 (PVT1) plays an important role in cancer development. In this review of a large number of studies on PVT1, we found that PVT1 is closely related to tumor onset, proliferation, invasion, epithelial–mesenchymal transformation, and apoptosis, as well as poor prognosis and radiotherapy and chemotherapy resistance in some cancers. This review comprehensively describes PVT1 expression in various cancers and presents novel approaches to the diagnosis and treatment of cancer.

PVT1 Expression Is a Predictor for Poor Survival of Prostate Cancer Patients

Objective:

Dysregulation of long noncoding RNA is associated with a variety of cancers and LncRNA has anticancer or carcinogenic activities. PVT1, as a long noncoding RNA, plays an important role in the development of cancer.

Methods:

We use R to download and analyze the data in TCGA database. ROC curve is generated to evaluate the significance of PVT1 expression for the diagnosis of prostate cancer. Chi-square test is used to test correlation between PVT1 expression and clinical pathological features. Survival curve and univariate and multivariate cox regression analysis is performed to compare differences in the effect on the survival rate between PVT1 high expression and low expression.

Results:

The expression of PTV1 in tumor tissues was significantly higher than that in normal tissues(P<2.2e-16). The difference of PTV1 expression was observed according to vital status (P = 0.0051) and Gleason score (P = 0.0012). The expression of PTV1 is significantly associated with T classification (P < 0.0001), N classification (P = 0.0499), PSA (P = 0.0001), Gleason Score (P < 0.0001), targeted molecular therapy (P = 0.0264) and vital status(P = 0.0036). The area under the ROC curve (AUC) was 0.860, which revealed PTV1 expression has excellent diagnostic value in prostate cancer. Patients with high PVT1 expression had a worse prognosis.

Conclusions:

PVT1 expression may be a biomarker for the diagnosis and prognosis of prostate cancer.

The effects of LncRNA PVT1 on clinical characteristics and survival in breast cancer patients: A protocol for systematic review and meta analysis

BACKGROUND

Currently, an increasing number of long noncoding RNAs (LncRNAs) have been reported to be abnormally expressed in human carcinomas and play a vital role in tumourigenesis. Some studies were carried out to investigate the influence of the expression of plasmacytoma variant translocation 1 (PVT1) on prognosis and its clinical significance in patients with breast cancer, while the results were contradictory and uncertain. A meta-analysis was conducted with controversial data to accurately assess the issue.

METHODS

A detailed search of relevant researches was performed in Wanfang, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, Chongqing VIP Chinese Science and Technology Periodical Database, PubMed, Embase, and Web of Science. Two reviewers independently conducted data extraction and literature quality evaluation. Odd ratio and its 95% confidence intervals were applied to evaluate the relationship between PVT1 and clinicopathological characteristics of breast cancer patients. Hazard ratios and its 95% confidence intervals were adopted to assess the prognostic effects of PVT1 on overall survival and disease-free survival. Meta-analysis was conducted with Stata 14.0 software.

RESULTS

This study will provide high-quality evidence-based medical evidence for the correlation between PVT1 expression and overall survival, and disease-free survival and clinicopathological features.

CONCLUSION

The study will provide updated evidence to evaluate whether the expression of PVT1 is in association with poor prognosis in patients with breast cancer.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/C2TYE.

Small Molecule Binds with Lymphocyte Antigen 6K to Induce Cancer Cell Death

Elevated gene expression of Lymphocyte antigen 6K (LY6K) in cancer cells is associated with poor survival outcomes in multiple different cancer types including cervical, breast, ovarian, lung, and head and neck cancer. Since inhibition of LY6K expression inhibits cancer cell growth, we set out to explore whether pharmacological inhibition of LY6K could produce the same effect. We screened small molecule libraries for direct binding to recombinant LY6K protein in a surface plasmon resonance assay. We found that NSC243928 directly binds to the full-length and mature forms of LY6K and inhibits growth of HeLa cells that express LY6K. NSC243928 did not display binding with LY6D or LY6E. Our data demonstrate a first-time proof of principle study that pharmacological inhibition of LY6K using small molecules in cancer cells is a valid approach to developing targeted therapies against LY6K. This approach will be specifically relevant in hard-to-treat cancers where LY6K is highly expressed, such as cervical, pancreatic, ovarian, head and neck, lung, gastric, and triple-negative breast cancers.

Oncogenic Role of PVT1 and Therapeutic Implications

PVT1, a long non-coding RNA has been implicated in a variety of human cancers. Recent advancements have led to increasing discovery of the critical roles of PVT1 in cancer initiation and progression. Novel insight is emerging about PVT1's mechanism of action in different cancers. Identifying and understanding the variety of activities of PVT1 involved in cancers is a necessity for the development of PVT1 as a diagnostic biomarker or therapeutic target in cancers where PVT1 is dysregulated. PVT1's varied activities include overexpression, modulation of miRNA expression, protein interactions, targeting of regulatory genes, formation of fusion genes, functioning as a competing endogenous RNA (ceRNA), and interactions with MYC, among many others. Furthermore, bioinformatic analysis of PVT1 interactions in cancers has aided understanding of the numerous pathways involved in PVT1 contribution to carcinogenesis in a cancer type-specific manner. However, these recent findings show that there is much more to be learned to be able to fully exploit PVT1 for cancer prognostication and therapy. In this review, we summarize some of the latest findings on PVT1's oncogenic activities, signaling networks and how targeting these networks can be a strategy for cancer therapy.

Polymorphisms in the PVT1 Gene and Susceptibility to the Lung Cancer in a Chinese Northeast Population: a Case-control Study

Background: Long non-coding RNA (lncRNA) PVT1 has been identified to be related to risk of a variety of cancers, such as gastric cancer, pancreatic cancer and follicular lymphoma. This study assesses the association between genetic polymorphisms of PVT1 and the susceptibility to lung cancer as well as gene-environmental interaction. Method: A hospital-based case-control study, including 515 lung cancer patients and 582 healthy controls, was carried out in Shenyang, China. Unconditional logistic regression analyses calculated the odds ratios (ORs) and their 95% confidence intervals (CIs) to assess the associations between polymorphisms of rs2608053, rs1561927, rs13254990 and susceptibility to lung cancer. The gene-environment interaction was evaluated by additive model and multiplicative model. Results: There were no statistically significant associations between rs2608053 and rs1561927 polymorphisms in PVT1 and risk of lung cancer in the overall population. The relationship between polymorphism rs13254990 in PVT1 gene and lung adenocarcinoma was significant. Composed with individuals carrying CC genotypes, TT genotype carriers were more likely to develop lung adenocarcinoma (adjusted OR=2.095; 95%CI=1.084-4.047, P=0.028). In the recessive model, it also showed a statistically significant difference (TT vs CT+CC: adjusted OR=2.251, 95%CI=1.174-4.318, P=0.015). In nonsmokers, individuals carrying genotype CT had a lower risk of lung cancer than those with CC genotype (adjusted OR=0.673, 95%CI=0.472-0.959, P=0.028). Comparing with the homozygous CC, the patients with the heterozygous CT had a lower risk of NCSLC in the non-smoking group (adjusted OR =0.685, 95%CI=0.477-0.984, P=0.040). Additionally, gene-environment interaction results were not statistically significant in either additive model or multiplicative model. Conclusion: The polymorphism rs13254990 in PVT1 gene is associated with the risk of lung adenocarcinoma in a Chinese northeast population.

Regulatory Mechanisms and Clinical Applications of the Long Non-coding RNA PVT1 in Cancer Treatment

Cancer is the second leading cause of death worldwide, and no obvious decline in incidence and mortality has occurred in recent years. It is imperative to further investigate the mechanisms underlying tumor progression. Long non-coding RNAs have received considerable attention in recent years because of their major regulatory roles in gene expression. Among them, PVT1 is well-studied, and substantial evidence indicates that PVT1 plays critical roles in the onset and development of cancers. Normally, PVT1 acts as an oncogenic factor by promoting cancer cell proliferation, invasion, metastasis, and drug resistance. Herein, we summarize current knowledge regarding the regulatory effects of PVT1 in cancer progression, as well as the related underlying mechanisms, such as interaction with Myc, modulation of miRNAs, and regulation of gene transcription and protein expression. In extracellular fluid, PVT1 mainly promotes cancer initiation, and it normally enhances cellular cancer characteristics in the cytoplasm and cell nucleus. Regarding clinical applications, its role in drug resistance and its potential use as a diagnostic and prognostic marker have received increasing attention. We hope that this review will contribute to a better understanding of the regulatory role of PVT1 in cancer progression, paving the way for the development of PVT1-based therapeutic approaches in cancer treatment.

Pan-Cancer and Single-Cell Modeling of Genomic Alterations Through Gene Expression

Cancer is a disease often characterized by the presence of multiple genomic alterations, which trigger altered transcriptional patterns and gene expression, which in turn sustain the processes of tumorigenesis, tumor progression, and tumor maintenance. The links between genomic alterations and gene expression profiles can be utilized as the basis to build specific molecular tumorigenic relationships. In this study, we perform pan-cancer predictions of the presence of single somatic mutations and copy number variations using machine learning approaches on gene expression profiles. We show that gene expression can be used to predict genomic alterations in every tumor type, where some alterations are more predictable than others. We propose gene aggregation as a tool to improve the accuracy of alteration prediction models from gene expression profiles. Ultimately, we show how this principle can be beneficial in intrinsically noisy datasets, such as those based on single-cell sequencing.

Long noncoding RNA PVT1: A highly dysregulated gene in malignancy

Recent studies have verified the contribution of several long noncoding RNAs (lncRNAs) in the carcinogenesis. Among the highly acknowledged lncRNAs is the human homolog of the plasmacytoma variant translocation gene, which is called PVT1. PVT1 resides near Myc oncogene and regulates the oncogenic process through modulation of several signaling pathways, such as TGF-β, Wnt/ β-catenin, PI3K/AKT, and mTOR pathways. This lncRNA has a circular form as well. Expression analyses and functional studies have appraised the oncogenic roles of PVT1 and circPVT1. Experiments in several cancer cell lines have shown that PVT1 silencing suppresses cancer cell proliferation, whereas its overexpression has the opposite effect. Its silencing has led to the accumulation of cells in the G0/G1 phase and diminished the number of cells in the S phase. Moreover, genome-wide association studies have signified the role of single nucleotide polymorphisms of this lncRNA in conferring risk of lymphoma in different populations. In the current study, we have summarized recent data about the role of PVT1 and circPVT1 in the carcinogenesis process.

Prognostic value of long non-coding RNA plasmacytoma variant translocation1 in human solid tumors: A meta-analysis

Plasmacytoma variant translocation 1 (PVT1) is highly expressed in a variety of cancer tissues and is related to the clinicopathological features and prognosis. However, the prognostic value of PVT1 is still controversial. Therefore, this systematic evaluation and meta-analysis were performed to evaluate the relationship between PVT1 expression and clinicopathological features.PubMed, EMBASE, Web of science, and Cochrane library databases were searched for literature collection according to inclusion criteria and exclusion criteria. The pooled hazard ratios (HRs) or odds ratios (ORs) were used to evaluate the association between PVT1 expression and overall survival, tumor size, tumor-node-metastasis (TNM) stage, lymph node metastasis, and distant metastasis.A total of 39 articles including 3974 patients were included in the study. The results showed that the expression of PVT1 was closely related to the overall survival rate of cancers (HR = 1.64, 95% confidence interval [CI]: 1.50-1.78, P < .000001). Subgroup analysis showed that the high expression of PVT1 was closely related to the low overall survival rate of patients with clear cell renal cell carcinoma, breast cancer, cervical cancer, colon cancer, epithelial ovarian cancer, gastric cancer, lung cancer, and osteosarcoma. In addition, the high expression of PVT1 was positively correlated with tumor size (OR = 1.50, 95% CI: 1.14-1.96, P = .004), TNM stage (OR = 3.39, 95% CI: 2.73-4.20, P < .00001), lymph node metastasis (OR = 2.60, 95% CI: 1.76-3.84, P < .00001), and distant metastasis (OR = 2.94, 95% CI: 1.90-4.56, P < .00001).PVT1 could serve as a marker for the size, TNM stage, metastasis, and prognosis of different type of cancers.

The Role of lncRNAs in the Distant Metastasis of Breast Cancer

Breast cancer (BC) remains the most frequently diagnosed cancer worldwide. Among breast cancer patients, distant metastasis and invasion is the leading cause of BC related death. Recently, long non-coding RNAs (lncRNAs), which used to be considered a genetic byproduct (owing to their unknown biological function), have been reported to be highly implicated in the development and progression of BC. In this review, we produce a summary of the functions and mechanisms of lncRNAs implicated in the different distant metastases of BC. The functions of lncRNAs have been divided into two types: oncogenic type and tumor suppressor. Furthermore, the majority of them exert their roles through the regulation of invasion, migration, epithelial-mesenchymal transition (EMT), and the metastasis process. In the final part, we briefly addressed future research prospects of lncRNAs, especially the testing methods through which to detect lncRNAs in the clinical work, and introduced several different tools with which to detect lncRNAs more conveniently. Although lncRNA research is still in the initial stages, it is a promising prognosticator and a novel therapeutic target for BC metastasis, which requires more research in the future.

Autophagy-Modulating Long Non-coding RNAs (LncRNAs) and Their Molecular Events in Cancer

Cancer is a global threat of health. Cancer incidence and death is also increasing continuously because of poor understanding of diseases. Although, traditional treatments (surgery, radiotherapy, and chemotherapy) are effective against primary tumors, death rate is increasing because of metastasis development where traditional treatments have failed. Autophagy is a conserved regulatory process of eliminating proteins and damaged organelles. Numerous research revealed that autophagy has dual sword mechanisms including cancer progressions and suppressions. In most of the cases, it maintains homeostasis of cancer microenvironment by providing nutritional supplement under starvation and hypoxic conditions. Over the past few decades, stunning research evidence disclosed significant roles of long non-coding RNAs (lncRNAs) in the regulation of autophagy. LncRNAs are RNA containing more than 200 nucleotides, which have no protein-coding ability but they are found to be expressed in most of the cancers. It is also proved that, autophagy-modulating lncRNAs have significant impacts on pro-survival or pro-death roles in cancers. In this review, we highlighted the recently identified autophagy-modulating lncRNAs, their signaling transduction in cancer and mechanism in cancer. This review will explore newly emerging knowledge of cancer genetics and it may provide novel targets for cancer therapy.

Long Non-coding RNA PVT1 Promotes Cell Proliferation and Migration by Silencing ANGPTL4 Expression in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is the most common biliary tract malignancy, with a low survival rate and limited treatment options. Long non-coding RNAs (lncRNAs) have recently been verified to have significant regulatory functions in many kinds of human cancers. It was discovered in this study that the lncRNA PVT1, whose expression is significantly elevated in CCA, could be a molecular marker of CCA. Experiments indicated that PVT1 knockdown greatly inhibited cell migration and proliferation in vitro and in vivo. According to RNA sequencing (RNA-seq) analysis, PVT1 knockdown dramatically influenced target genes associated with cell angiogenesis, cell proliferation, and the apoptotic process. RNA immunoprecipitation (RIP) analysis demonstrated that, by binding to epigenetic modification complexes (PRC2), PVT1 could adjust the histone methylation of the promoter of ANGPTL4 (angiopoietin-like 4) and, thus, promote cell growth, migration, and apoptosis progression. The data verified the significant functions of PVT1 in CCA oncogenesis, and they suggested that PVT1 could be a target for CCA intervention.