Long Noncoding RNA PVT1 as a Novel Predictor of Metastasis, Clinicopathological Characteristics and Prognosis in Human Cancers: a Meta-Analysis

Long non-coding RNA as a potential diagnostic and prognostic biomarker in melanoma: A systematic review and meta-analysis

Recently, long noncoding RNAs (lncRNAs) have been applied as biomarkers for melanoma patients. In this systematic review and meta-analysis, we investigated the diagnostic and prognostic value of lncRNAs. We used the keywords 'lncRNA' and 'melanoma' to search databases for studies published before June 14th, 2023. The specificity, sensitivity and AUC were utilized to assess diagnostic accuracy and the prognostic value was assessed using overall survival, progression-free survival and disease-free survival hazard ratios. After screening 1191 articles, we included seven studies in the diagnostic evaluation section and 17 studies in the prognosis evaluation section. The Reitsma bivariate model estimated a cumulative sensitivity of 0.724 (95% CI: 0.659-0.781, p < 0.001) and specificity of 0.812 (95% CI: 0.752-0.859, p < 0.001). The pooled AUC was 0.780 (95% CI: 0.749-0.811, p < 0.0001). The HR for overall survival was 2.723 (95% CI: 2.259-3.283, p < 0.0001). Two studies reported an HR for overall survival less than one, with an HR of 0.348 (95% CI: 0.200-0.607, p < 0.0002). The HR for progression-free survival was 2.913 (95% CI: 2.050-4.138, p < 0.0001). Four studies reported an HR less than one, with an HR of 0.457 (95% CI: 0.256-0.817). The HR for disease-free survival was 2.760 (95% CI: 2.009-3.792, p < 0.0001). In conclusion, the expression of lncRNAs in melanoma patients affects survival and prognosis. LncRNAs can also be employed as diagnostic biomarkers.

Long non-coding RNA PVT1 promotes the proliferation, migration and EMT process of ovarian cancer cells by regulating CTGF

Ovarian cancer remains one of the most common gynecological malignancies with a poor prognosis. The present study investigated the roles of long non-coding RNA plasmacytoma variant translocation 1 (lncRNA PVT1) in the regulation of the malignant phenotype of ovarian cancer cells, including cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT). SKOV3 and CAOV3 cells were transfected with small interfering RNA (siRNA) targeting lncRNA PVT1 (si-PVT1) or control siRNA and the si-PVT1 transfected cells were co-cultured with recombinant human connective tissue growth factor (rhCTGF). The proliferation, migration and invasion abilities of the cells were examined via Cell Counting Kit-8, colony formation, wound-healing and Transwell assays. The relative expression levels of lncRNA PVT1, CTGF, E-cadherin and vimentin were analyzed using reverse transfection-quantitative polymerase chain reaction, and western blotting was employed to detect the protein levels of CTGF, E-cadherin and vimentin. The expression of lncRNA PVT1 was significantly reduced in SKOV3 and CAOV3 cells following transfection with si-PVT1. In addition, the proliferation, migration and invasion abilities of SKOV3 and CAOV3 cells were repressed following lncRNA PVT1 knockdown. The knockdown of lncRNA PVT1 also reduced the expression of CTGF and vimentin, and increased the expression of E-cadherin. The changes in the proliferation, migration and invasion of the cells induced by transfection with si-PVT1 were partially attenuated in the presence of rhCTGF. Furthermore, co-culture with rhCTGF reversed the si-PVT1-induced changes in the expression of EMT-associated proteins. In conclusion, lncRNA PVT1 promotes the proliferation, migration, invasiveness and EMT process of ovarian cancer cells, and CTGF contributes to the effect of lncRNA PVT1.

Long non-coding RNA PVT1 facilitates cell migration and invasion by regulating miR-148a-3p and ROCK1 in breast cancer

PURPOSE

Breast cancer (BC) is one of the most common malignant tumors for women. The role and potential mechanisms of long non-coding RNA plasmacytoma variant translocation 1 (lncRNA PVT1) were explored in BC cell migration and invasion.

METHODS

PVT1, miR-148a-3p and Rho‑associated, coiled‑coil containing protein kinase 1 (ROCK1) mRNA expressions were detected using real-time fluorescent quantitative polymerase chain reaction (qRT-PCR). The ROCK1 protein expression was detected by Western blotting. The relationship of PVT1, miR-148a-3p and ROCK1 was analyzed by Dual Luciferase activity, RNA immunoprecipitation (RIP) and Spearman correlation analysis. Cell invasion and migration were detected by Transwell assay.

RESULTS

Upregulation of PVT1 and ROCK1, and downregulation of miR-148a-3p were observed in BC tissues and cell lines. According to the analysis of Dual Luciferase activity, RIP and Spearman correlation analysis, miR-148a-3p directly binds to PVT1, and ROCK1 is a target of miR-148a-3p. In addition, PVT1 regulated the cells migration and invasion by regulating miR-148a-3p and ROCK1 expression.

CONCLUSION

These data demonstrated that PVT1 was upregulated and facilitated to the cell migration and invasion of BC by the regulation of miR-148a-3p and ROCK1, indicating that PVT1 may be a potential biomarker of BC diagnosis and treatment.

Long non-coding RNA MIR31HG as a prognostic predictor for malignant cancers: A meta- and bioinformatics analysis

Background

The possible regulatory mechanism of MIR31HG in human cancers remains unclear, and reported results of the prognostic significance of MIR31HG expression are inconsistent.

Methods

The meta‐analysis and related bioinformatics analysis were conducted to evaluate the role of MIR31HG in tumor progression.

Results

The result showed that high MIR31HG expression was not related to prognosis. However, in the stratified analysis, we found that the overexpression of MIR31HG resulted in worse OS, advanced TNM stage, and tumor differentiation in respiratory system cancers. Moreover, our results also found that MIR31HG overexpression was related to shorter OS in cervical cancer patients and head and neck tumors. In contrast, the MIR31HG was lower in digestive system tumors which contributed to shorter overall survival, advanced TNM stage, and distant metastasis. Furthermore, the bioinformatics analysis showed that MIR31HG was highly expressed in normal urinary bladder, small intestine, esophagus, stomach, and duodenum and low in colon, lung, and ovary. The results obtained from FireBrowse indicated that MIR31HG was highly expressed in LUSC, CESC, HNSC, and LUAD and low in STAD and BLCA. Gene Ontology analysis showed that the co‐expressed genes of MIR31HG were most enriched in the biological processes of peptide metabolism and KEGG pathways were most enriched in Ras, Rap1, and PI3K‐Akt signaling pathway.

Conclusion

MIR31HG may serve as a potential biomarker in human cancers.

Long Noncoding RNA PVT1 Is Regulated by Bromodomain Protein BRD4 in Multiple Myeloma and Is Associated with Disease Progression

Long noncoding RNAs (lncRNAs) are deregulated in human cancers and are associated with disease progression. Plasmacytoma Variant Translocation 1 (PVT1), a lncRNA, is located adjacent to the gene MYC, which has been linked to multiple myeloma (MM). PVT1 is expressed in MM and is associated with carcinogenesis. However, its role and regulation remain uncertain. We examined PVT1/MYC expression using real-time PCR in plasma cells purified from 59 monoclonal gammopathy of undetermined significance (MGUS) and 140 MM patients. The MM cell lines KMS11, KMS12PE, OPM2, and RPMI8226 were treated with JQ1, an MYC super-enhancer inhibitor, or MYC inhibitor 10058-F4. The expression levels of PVT1 and MYC were significantly higher in MM than in MGUS (p < 0.0001) and were positively correlated with disease progression (r = 0.394, p < 0.0001). JQ1 inhibited cell proliferation and decreased the expression levels of MYC and PVT1. However, 10054-F4 did not alter the expression level of PVT1. The positive correlation between MYC and PVT1 in patients, the synchronous downregulation of MYC and PVT1 by JQ1, and the lack of effect of the MYC inhibitor on PVT1 expression suggest that the expression of these two genes is co-regulated by a super-enhancer. Cooperative effects between these two genes may contribute to MM pathogenesis and progression.

Unleash multifunctional role of long noncoding RNAs biomarker panel in breast cancer: a predictor classification model

Aim: We aimed to explore the circulating expression profile of nine lncRNAs (MALAT1, HOTAIR, PVT1, H19, ROR, GAS5, ANRIL, BANCR, MIAT) in breast cancer (BC) patients relative to normal and risky individuals. Methods: Serum relative expressions of the specified long non-coding RNAs were quantified in 155 consecutive women, using quantitative reverse-transcription PCR. Random Forest (RF) and decision tree were also applied. Results: Significant MALAT1 upregulation and GAS5 downregulation could discriminate risky women from healthy controls. Overexpression of the other genes showed good diagnostic performances. Lower GAS5 levels were associated with metastasis and recurrence. RF model revealed a better performance when combining gene expression patterns with risk factors. Conclusion: The studied panel could be utilized as diagnostic/prognostic biomarkers in BC, providing promising epigenetic-based therapeutic targets.

High amplification of PVT1 and MYC predict favorable prognosis in early ovarian carcinoma

INTRODUCTION

The objective of this study was to evaluate the status of MYC and PVT1, which are frequently amplified in malignant tumors, and to assess their biological features according to histological subtypes in early-stage epithelial ovarian cancer (EOC).

METHODS

Formalin-fixed and paraffin-embedded (FFPE) samples of 64 EOC tissues in International Federation of Gynecology and Obstetrics stages I-II and 20 normal ovarian tissues were analyzed for copy number and mRNA expression of MYC and PVT1 by qPCR and for MYC protein expression by immunohistochemistry. MYC protein expression was assessed by western blotting in a PVT1 siRNA-transfected ovarian cancer cell line. MYC and PVT1 was assessed as a prognostic factor using Kaplan-Meier analysis. The median follow-up period was 49.9 months and 17 cases in 64 of EOC recurred during follow-up.

RESULTS

Copy number variations showed significantly higher MYC and PVT1 in EOC than in normal ovaries. The copy number of PVT1 was significantly higher in serous carcinoma than in the other histological types. The mRNA of MYC and PVT1 was also higher in cancer tissues and showed a strong correlation in all histological subtypes. Immunohistochemistry revealed a positive association between the phosphorylated MYC (pMYC) index and high expression of proliferation markers, such as Ki-67 index, and a negative correlation between pMYC protein and the PVT1 copy number. Knockdown of PVT1 in ovarian cancer cell lines resulted in upregulation of MYC protein and pMYC. Kaplan-Meier survival analysis showed that low copy numbers of both MYC and PVT1 were associated with a statistically significantly poor prognosis.

CONCLUSION

Expression of pMYC and the Ki-67 index were affected by the PVT1 copy number but not mRNA. A high PVT1 copy number in FFPE samples might suggest favorable prognosis in early ovarian cancers.

Hypoxia induces the activation of hepatic stellate cells through the PVT1-miR-152-ATG14 signaling pathway

Increasing studies have indicated that hypoxia serves as a pivotal microenvironmental factor that facilitates activation of hepatic stellate cells (HSCs). However, the mechanism by which hypoxia activates HSCs is not clear. Here, we demonstrated that plasmacytoma variant translocation 1 (PVT1) and autophagy were overexpressed in liver fibrotic specimens. In primary mouse HSCs, both PVT1 and autophagy were induced by hypoxia. Further study showed that hypoxia-induced autophagy depended on expression of PVT1 and miR-152 in HSCs. Luciferase reporter assay indicated that autophagy-related gene 14 (ATG14) was a direct target of miR-152. In addition, inhibition of autophagy by 3-methyladenine and Beclin-1 siRNA impeded activation of HSCs cultured in 1% O₂. Taken together, autophagy induction via the PVT1-miR-152-ATG14 signaling pathway contributes to activation of HSCs under hypoxia condition.

Long non-coding RNA PVT1 interacts with MYC and its downstream molecules to synergistically promote tumorigenesis

Numerous studies have shown that non-coding RNAs play crucial roles in the development and progression of various tumor cells. Plasmacytoma variant translocation 1 (PVT1) mainly encodes a long non-coding RNA (lncRNA) and is located on chromosome 8q24.21, which constitutes a fragile site for genetic aberrations. PVT1 is well-known for its interaction with its neighbor MYC, which is a qualified oncogene that plays a vital role in tumorigenesis. In the past several decades, increasing attention has been paid to the interaction mechanism between PVT1 and MYC, which will benefit the clinical treatment and prognosis of patients. In this review, we summarize the coamplification of PVT1 and MYC in cancer, the positive feedback mechanism, and the latest promoter competition mechanism of PVT1 and MYC, as well as how PVT1 participates in the downstream signaling pathway of c-Myc by regulating key molecules. We also briefly describe the treatment prospects and research directions of PVT1 and MYC.

Long noncoding RNA HOXD-AS1 in various cancers: a meta-analysis and TCGA data review

Background and aims: HOXD antisense growth-associated long noncoding RNA (HOXD-AS1) was reported to be upregulated in various cancers, such as gastric cancer, hepatocellular carcinoma, colorectal cancer, and glioma. Here, we conducted a meta-analysis and The Cancer Genome Atlas data review to investigate the clinicopathologic and prognostic value of HOXD-AS1 in patients with malignant tumors.

Materials and methods: Systematic literatures were searched from PubMed, Medline, Cochrane Library, Web of Science, EMBASE database, Ovid, Chinese CNKI, and the Chinese WanFang database. The role of HOXD-AS1 in cancers was evaluated by pooled ORs and HRs with 95% CIs. The Cancer Genome Atlas dataset was used to explore the prognostic value of HOXD-AS1 in various cancers.