Long-Noncoding RNA PCAT6 Aggravates Osteosarcoma Tumourigenesis via the MiR-143-3p/ZEB1 Axis

Osteosarcoma in a ceRNET perspective

Osteosarcoma (OS) is the most prevalent and fatal type of bone tumor. It is characterized by great heterogeneity of genomic aberrations, mutated genes, and cell types contribution, making therapy and patients management particularly challenging. A unifying picture of molecular mechanisms underlying the disease could help to transform those challenges into opportunities.This review deeply explores the occurrence in OS of large-scale RNA regulatory networks, denominated "competing endogenous RNA network" (ceRNET), wherein different RNA biotypes, such as long non-coding RNAs, circular RNAs and mRNAs can functionally interact each other by competitively binding to shared microRNAs. Here, we discuss how the unbalancing of any network component can derail the entire circuit, driving OS onset and progression by impacting on cell proliferation, migration, invasion, tumor growth and metastasis, and even chemotherapeutic resistance, as distilled from many studies. Intriguingly, the aberrant expression of the networks components in OS cells can be triggered also by the surroundings, through cytokines and vesicles, with their bioactive cargo of proteins and non-coding RNAs, highlighting the relevance of tumor microenvironment. A comprehensive picture of RNA regulatory networks underlying OS could pave the way for the development of innovative RNA-targeted and RNA-based therapies and new diagnostic tools, also in the perspective of precision oncology.

LncRNA PCAT6 mediates UBFD1 expression via sponging miR-545-3p in breast cancer cells

Background

LncRNA PCAT6 has been shown to involve in carcinogenesis of different tumors. In this study, we investigated underline mechanism by which PCAT6 promoted breast cancer cell progression.

Methods

RIP was used to identify lncRNAs associated with IMP1. Bioinformatics assays were used to predict potential miRNAs that interact with PCAT6 and mRNAs that are targeted by miR-545-3p. RNA-seq and RT-qPCR were used to analyze differential expression of lncRNAs and miRNA-targeted genes. Luciferase reporter and RNA pull-down assays were performed to identify the molecular interactions between PCAT6 and individual miRNAs. The role of PCAT6-mediated cell proliferation and invasion were tested by CCK-8 and transwell assays following loss-of-function and gain-of-function effects.

Results

We identified that PCAT6 is one of the lncRNAs that associated with IMP1. PCAT6 not only binds to IMP1, but also acts as a ceRNA to interact with multiple miRNAs, including miR-545-3p. Binding of IMP1 destabilized PCAT6, while competitive interaction with miR-545-3p allowed PCAT6 to positively regulate UBFD1 expression. Silencing UBFD1 mRNA could effectively rescue PCAT6-induced cell proliferation and invasive abilities.

Conclusions

Our study provided evidence that PCAT6 activates UBFD1 expression via sponging miR-545-3p to increase carcinogenesis of breast cancer cells. Based on the nature of UBFD1 as a polyubiquitin binding protein, our study suggested that ubiquitin pathway might contribute to breast cancer progression.

LncRNA LINC00667 gets involved in clear cell renal cell carcinoma development and chemoresistance by regulating the miR-143-3p/ZEB1 axis

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is identified as a malignant tumor in the urinary tract. The research was an attempt to probe the biological function and molecular mechanism of lncRNA LINC00667 in ccRCC development.

METHODS

qRT-PCR monitored LINC00667, miR-143-3p, and ZEB1 levels. The models of LINC00667, miR-143-3p, and ZEB1 overexpression or knockdown were constructed in ccRCC cells. Cell proliferation, apoptosis, migration, and invasion of the cells were detected. The levels of apoptosis-associated proteins and epithelial-mesenchymal transition (EMT)-related proteins, and ZEB1 were detected by WB. Dual-luciferase reporter assay and RNA pull-down assay identified the binding association between LINC00667 and miR-143-3p, miR-143-3p and ZEB1. Moreover, a xenograft tumor model in nude mice was used for evaluating tumor growth in vivo.

RESULTS

LINC00667 and ZEB1 displayed high expression in ccRCC tissues and cells. miR-143-3p was lowly expressed in ccRCC tissues and cells. LINC00667 targeted and repressed miR-143-3p, which inhibited ZEB1 expression in a targeted manner. Overexpression of LINC00667 facilitated ccRCC cell proliferation, migration, invasion and EMT and retarded apoptosis, whereas LINC00667 knockdown or miR-143-3p overexpression exerted reverse effects. The rescue experiments indicated that overexpressing miR-143-3p dampened LINC00667-mediated oncogenic effects. Overexpressing ZEB1 diminished miR-143-3p-mediated tumor-suppressive effects. In-vivo experiments displayed that overexpression of LINC00667 contributed to the tumor growth of ccRCC cells, in contrast to miR-143-3p overexpression, which restrained the tumor growth.

CONCLUSIONS

LINC00667 is up-regulated in ccRCC and enhances the ZEB1 expression by targeting miR-143-3p, which in turn accelerates ccRCC progression and induces chemoresistance.

MicroRNA-143 expression inhibits the growth and the invasion of osteosarcoma

Background

Osteosarcoma (OS) is a common malignant tumor, which occurs in the metaphysis of the long diaphysis from mesenchymal tissue. Previous studies have indicated that expression of microRNA-143 (miR-143) could affect cancer cell proliferation, migration and invasion. The present research was performed to figure out whethermiR-143 expression inhibits the growth and the invasion of OS.

Methods

We conducted a literature search in the electronic databases of Medline, Embase, Web of Science, and the Cochrane Library, SinoMed, WanFang, China national knowledge infrastructure (CNKI) until January 2022. We used Review Manager 5.3 software to conduct our research.

Results

Twelve eligible articles were included, 5 articles were reported outcomes about mice, 11 articles were reported outcomes about human. The results of mice demonstrated that the miR-143 group had significantly better results in tumor volume, tumor weight and survival rate. The results of human demonstrated that the high level of miR-143 group had significantly better results in the 3-year, 4-year, and 5-year survival rate, lung metastasis and tumor grade.

Conclusions

MiR-143 has potentially important value in the treatment and prognosis of OS. However, more reliable animal and clinical trials are needed before miR-143 based therapies can be transferred from animal studies to human applications.

PCAT6 May Be a Whistler and Checkpoint Target for Precision Therapy in Human Cancers

Simple Summary

Prostate cancer-associated transcript 6 (PCAT6), as a newly discovered carcinogenic long non-coding RNA (lncRNA), is abnormally expressed in multiple diseases. With the accumulation of studies on PCAT6, we have a deeper understanding of its biological functions and mechanisms. Therefore, in this review, the various molecular mechanisms by which PCAT6 promotes multiple tumorigenesis and progression are summarized and discussed. Furthermore, its potential diagnostic, prognostic, and immunotherapeutic values are also clarified.

Abstract

LncRNAs are involved in the occurrence and progressions of multiple cancers. Emerging evidence has shown that PCAT6, a newly discovered carcinogenic lncRNA, is abnormally elevated in various human malignant tumors. Until now, PCAT6 has been found to sponge various miRNAs to activate the signaling pathways, which further affects tumor cell proliferation, migration, invasion, cycle, apoptosis, radioresistance, and chemoresistance. Moreover, PCAT6 has been shown to exert biological functions beyond ceRNAs. In this review, we summarize the biological characteristics of PCAT6 in a variety of human malignancies and describe the biological mechanisms by which PCAT6 can facilitate tumor progression. Finally, we discuss its diagnostic and prognostic values and clinical applications in various human malignancies.

Oncogenic functions of ZEB1 in pediatric solid cancers: interplays with microRNAs and long noncoding RNAs

The transcription factor Zinc finger E-box binding 1 (ZEB1) displays a range of regulatory activities in cell function and embryonic development, including driving epithelial-mesenchymal transition. Several aspects of ZEB1 function can be regulated by its functional interactions with noncoding RNA types, namely microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). Increasing evidence indicates that ZEB1 importantly influences cancer initiation, tumor progression, metastasis, and resistance to treatment. Cancer is the main disease-related cause of death in children and adolescents. Although the role of ZEB1 in pediatric cancer is still poorly understood, emerging findings have shown that it is expressed and regulates childhood solid tumors including osteosarcoma, retinoblastoma, neuroblastoma, and central nervous system tumors. Here, we review the evidence supporting a role for ZEB1, and its interplays with miRNAs and lncRNAs, in pediatric cancers.

The Role of lncRNA PCAT6 in Cancers

Long non-coding RNA (lncRNA) PCAT6 is a member of the Prostate Cancer Associated Transcripts family of molecules. In this review, we focus on the latest studies involving PCAT6 in the diagnosis, treatment, and prognosis of malignant tumors of the digestive, respiratory, urinary, reproductive, motion, and nervous systems. PCAT6 was found to be highly expressed in gastric cancer, colon cancer, hepatocellular carcinoma, lung cancer, bladder cancer, ovarian cancer, breast cancer, cervical cancer, osteosarcoma, glioblastoma, and other tumors. PCAT6 can promote the development and progression of different types of malignant tumors through various mechanisms. Overall, these findings suggest that PCAT6 may play an increasingly vital role in the clinical assessment of these malignant tumors. It can function as an oncogene and may be used as a potential new prognostic biomarker of these tumors.

PCAT6 may be a new prognostic biomarker in various cancers: a meta-analysis and bioinformatics analysis

Background

LncRNA prostate cancer-associated transcript 6 (PCAT6) has been reported to be dysregulated in several cancers and is associated with tumor progression. Here, we have performed a meta-analysis to assess the general prognostic role of PCAT6 in malignancies.

Methods

Four public databases (Embase, Pubmed, Web of Science, Cochrane Library) were used to identify eligible studies, then data was extracted and associations between prognostic indicators and clinical characteristics were combined to estimate hazard ratio (HR) or odds ratio (OR) with a 95% confidence interval (CI). Publication bias was measured using the Begg's test, and the stability of the combined results was measured using sensitivity analysis. Subsequently, results were validated using Gene Expression Profiling Interactive Analysis (GEPIA) and the National Genomics Data Center (NGDC).

Results

Ten studies were considered eligible for inclusion. In total, 937 patients and eight types of cancer were included. Our results revealed that overexpression of PCAT6 was significantly associated with a shorter OS (HR = 1.82; 95% CI, [1.40, 2.38]; P < 0.0001) and progression-free survival (PFS) (HR = 1.66; 95% CI, [1.22, 2.25]; P < 0.0001) in cancer patients, and that PCAT6 overexpression was significantly associated with individual tumor clinicopathological parameters, including TNM stage (OR = 0.29; 95% CI, [0.09, 0.94]; P = 0.04), gender (OR = 1.84; 95% CI, [1.31, 2.59]; P = 0.0005), and whether the tumor was metastatic (OR = 5.02; 95% CI, [1.36, 18.57]; P = 0.02). However, PCAT6 overexpression was not correlated with patient age and tumor differentiation. PCAT6 expression was significantly up-regulated in four types of cancer, which was validated using the GEPIA cohort. Combining OS and disease-free survival (DFS) of these four types of cancer revealed a shorter OS and DFS in patients with PCAT6 overexpression. PCAT6 expression in various types of cancer was also validated in NGDC. A total of eight cancers were analyzed and PCAT6 was highly expressed in all eight cancers. Further functional predictions suggest that PCAT6 is correlated with tumor prognosis, and that PCAT6 may be useful as a new tumor-specific marker.

Conclusions

LncRNA PCAT6 is highly expressed in multiple cancer types and its upregulation was significantly associated with patient prognosis and poorer clinical features, thereby suggesting that PCAT6 may be a novel prognostic factor in multiple cancer types.

A five metastasis-related long noncoding RNA risk signature for osteosarcoma survival prediction

Background

Osteosarcoma is a highly malignant and common bone tumour with an aggressive disease course and a poor prognosis. Previous studies have demonstrated the relationship between long noncoding RNAs (lncRNAs) and tumorigenesis, metastasis, and progression.

Methods

We utilized a large cohort from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database osteosarcoma project to identify potential lncRNAs related to the overall survival of patients with osteosarcoma by using univariate and multivariate Cox proportional hazards regression analyses. Kaplan–Meier curves were generated to evaluate the overall survival difference between patients in the high-risk group and the low-risk group. A time-dependent receiver operating characteristic curve (ROC) was employed, and the area under the curve (AUC) of ROC was measured to assess the sensitivity and specificity of the multi-lncRNA signature.

Results

Five lncRNAs (RP11-128N14.5, RP11-231|13.2, RP5-894D12.4, LAMA5-AS1, RP11-346L1.2) were identified, and a five-lncRNA signature was constructed. The AUC for predicting 5-year survival was 0.745, which suggested good performance of the five-lncRNA signature. In addition, functional enrichment analysis of the five-lncRNA-correlated protein-coding genes (PCGs) was performed to show the biological function of the five lncRNAs. Additionally, PPI network suggested RTP1 is a potential biomarker that regulates the prognosis of osteosarcoma.

Conclusions

We developed a five-lncRNA signature as a potential prognostic indicator for osteosarcoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-021-00972-5.

Promising role of long non-coding RNA PCAT6 in malignancies

Long non-coding RNAs (lncRNAs), a newly identified class of non-coding RNA (ncRNA), are defined as RNA molecules at least 200 nucleotides in length that are not translated into proteins. LncRNAs contribute to a wide range of biological processes and are master regulators of disease occurrence, development, and response to therapy in human malignancies. The lncRNA prostate cancer‑associated transcript 6 (PCAT6) is upregulated in various human malignancies, including lung cancer, hepatocellular carcinoma, cervical cancer, osteosarcoma, glioblastoma, colorectal cancer, breast cancer, gastric cancer, gastrointestinal stromal tumors, and pancreatic ductal adenocarcinoma. High expression of PCAT6 is closely correlated with aggressive clinicopathological characteristics and poor prognosis in cancer patients, suggesting it is an oncogenic lncRNA. PCAT6 overexpression also facilitates cell proliferation, invasion, and migration while attenuating apoptosis, indicating that it might serve as a new prognostic biomarker and therapeutic target for malignancies. Here, we discuss the molecular mechanisms, regulatory functions, and potential clinical applications of PCAT6 in cancer.

LncRNA PCAT6 regulates the progression of pituitary adenomas by regulating the miR-139-3p/BRD4 axis

BACKGROUND

Dysregulated lncRNA PCAT6 was discovered in many cancers excluding pituitary adenomas (PA). Therefore, we explored the role of PCAT6 in PA in this research.

METHODS

Abnormally expressed miRNAs were analyzed by bioinformatics and RT-qPCR. The target and regulator of miR-139-3p were determined by bioinformatics, dual-luciferase reporter assay, or RIP. The correlation among PCAT6, miR-139-3p, and BRD4 was further analyzed. The viability, apoptosis, cell cycle distribution of PA cells, as well as their ability to invade, migrate, and proliferate, were tested after transfection through CCK-8, flow cytometry, transwell, wound healing, and colony formation assays. After construction of transplanted-tumor model in nude mice, cell apoptosis in the tumor was detected by TUNEL. The expressions of PCAT6, BRD4, miR-139-3p, and apoptosis-related factors in PA tissues, cells, or tumor tissues were detected by RT-qPCR, Western blot, or IHC.

RESULTS

PCAT6 and BRD4 were high-expressed but miR-139-3p was low-expressed in PA. Both the 3'-untranslated regions of PCAT6 and BRD4 mRNAs were demonstrated to contain a potential binding site for miR-139-3p. PCAT6 was positively correlated to BRD4, and miR-139-3p was negatively correlated to PCAT6 and BRD4. MiR-139-3p mimic, shPCAT6 and siBRD4 inhibited the viability, migration, invasion, and proliferation of PA cells while inducing apoptosis. MiR-139-3p mimic and shPCAT6 inhibited the cell cycle progression of PA cells, decreased the weight and volume of the xenotransplanted tumor, and reduced the levels of Bcl-2 and BRD4 while enhancing the levels of Bax, miR-139-3p, and Cleaved caspase-3. MiR-139-3p inhibitor caused the opposite effect of miR-139-3p mimic and further reversed the effect of shPCAT6 on on PA cells.

CONCLUSION

PCAT6 regulated the progression of PA via modulating the miR-139-3p/BRD4 axis, which might provide a novel biomarker for the prevention, diagnosis, and treatment of PA.