lncRNA Prostate Cancer-associated Transcript 6 Research Articles

LncRNA PCAT6 is a predictor of poor prognosis of colorectal cancer.

The long non-coding RNA (lncRNA) prostate cancer-associated transcript 6 (PCAT6) has been studied in many cancers, yet its relationship with colorectal cancer (CRC) remains poorly defined. Here, we conducted an analysis of The Cancer Genome Atlas (TCGA) database to better clarify the role of PCAT6 in this cancer type. Wilcoxon rank-sum tests were utilized to assess relative levels of PCAT6 in CRC tumors and normal tissues, while logistic regression analyses were utilized to compare the relationships between PCAT6 levels and clinicopathological findings. Kaplan-Meier curves and Cox regression analyses were used to gauge correlations between PCAT6 and patient survival outcomes, while the biological roles of this lncRNA were investigated via a gene set enrichment analysis (GSEA) approach. The expression level of PCAT6 in CRC cell lines was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). PCAT6 levels were significantly correlated with CRC patient lymph node metastasis (N) stage [odds ratio (OR) =1.8 for N1 & N2 vs. N0], lymphatic invasion [OR =1.9 for yes vs. no), distant metastasis (M stage) (OR =2.1 for M1 vs. M0), carcinoembryonic antigen (CEA) level (OR =1.9 for >5 vs. ≤5), perineural invasion (OR =1.9 for yes vs. no), pathologic stage (OR =1.9 for stage III/IV vs. stage I/II), and neoplasm type (OR =2.1 for rectal adenocarcinoma vs. colon adenocarcinoma) (all P<0.05). CRC patients expressing higher PCAT6 levels exhibited poorer survival outcomes than those expressing low levels of this lncRNA (P=0.017), and in univariate analyses, higher PCAT6 levels were linked to worse overall survival [hazard ratio (HR) =1.540; 95% confidence interval (CI): 1.079-2.199; P=0.017], with this relationship also being preserved in a multivariate analysis (HR =6.892; 95% CI: 1.713-27.727, P=0.007). GSEA revealed high PCAT6 expression to be linked to differential DNA methylation enrichment, with high PCAT6 levels being associated with changes in base excision repair, cellular senescence, G2/M DNA damage checkpoint, chromatin-modifying enzyme, and gene silencing by RNA activity. The high expression of lncRNA PCAT6 in CRC cell lines was demonstrated by PCR experiments. PCAT6 represents a promising prognostic biomarker of poor CRC patient survival outcomes, with DNA methylation and RNA-mediated gene silencing being potentially promising mechanistic pathways whereby this lncRNA may shape patient outcomes.

Knockdown of lncRNA PCAT6 suppresses the growth of non-small cell lung cancer cells by inhibiting macrophages M2 polarization via miR-326/KLF1 axis

ABSTRACT Non-small cell lung cancer (NSCLC) is the most common malignant tumor of lung, which seriously threatens the life of people. It has been reported that lncRNA prostate cancer-associated transcript 6 (PCAT6) could facilitate the metastasis of NSCLC cells. However, whether lncRNA PCAT6 in NSCLC cells could affect the tumor microenvironment (TME) remains unclear. In the present study, the level of PCAT6 in NSCLC cells was detected using RT-qPCR. The effects of PCAT6 knockdown on the viability and apoptosis in NSCLC cells were detected with CCK-8 and flow cytometry assay. NSCLC cell-derived exosomes were isolated with ultracentrifugation. Next, transwell assay was conducted to assess the migration and invasion of NSCLC cells. Dual-luciferase reporter assay was performed to verify the relationship among PCAT6, miR-326, and KLF1 in A549 cells. In addition, nanoparticle tracking analysis (NTA) was applied to detect the particle size of isolated exosomes. Moreover, ELISA assay was performed to detect the levels of IL-1β and IL-10 in the supernatant of macrophage. We found knockdown of PCAT6 significantly inhibited the viability, migration, and invasion of NSCLC cells. In addition, dual-luciferase reporter assay illustrated that miR-326 was the target of PCAT6 and KLF1 was the target of miR-326 in NSCLC cells. Moreover, NSCLC cells-derived exosomes could promote macrophages M2 polarization by transporting PCAT6. Meanwhile, macrophages M2 polarization was able to promote the metastasis and epithelial-mesenchymal transition (EMT) process of NSCLC cells via regulating PCAT6/miR-326/KLF1 axis. Taken together, knockdown of lncRNA PCAT6 suppressed the growth of NSCLC cells by inhibiting macrophages M2 polarization via miR-326/KLF1 axis.

Long non-coding RNA prostate cancer-associated transcript 6 inhibited gefitinib sensitivity of non-small cell lung cancer by serving as a competing endogenous RNA of miR-326 to up-regulate interferon-alpha receptor 2

ABSTRACT The critical roles of lncRNAs in drug resistance of malignancies have been widely recognized. This investigation aims to study the function of lncRNA PCAT6 in the resistance of non-small cell lung cancer (NSCLC) to gefitinib. In our study, we demonstrated that prostate cancer-associated transcript 6 (PCAT6) was upregulated in gefitinib-resistant NSCLC. PCAT6 knockdown inhibited gefitinib resistance of NSCLC, as indicated by decreased IC50 value, proliferation, and metastasis, and increased cell apoptosis. Besides, PCAT6 could directly target miR-326 in gefitinib-resistant NSCLC cells and augment NSCLC resistance to gefitinib by serving as ceRNA of miR-326. Furthermore, interferon-alpha receptor 2 (IFNAR2) was validated as a downstream target of miR-326 and miR-326 reduced resistance to gefitinib by inhibiting IFNAR2 expression. Our investigation identified that PCAT6 enhanced gefitinib resistance of NSCLC via miR-326/IFNAR2 axis, which might offer a new therapeutic strategy against gefitinib resistance of NSCLC patients.

LncRNA PCAT1 might coordinate ZNF217 to promote CRC adhesion and invasion through regulating MTA2/MTA3/Snai1/E-cadherin signaling.

LncRNA prostate cancer-associated transcript 1 (PCAT1) is a well-known oncogene, but the mechanisms of exosomes PCAT1 in colorectal cancer (CRC) remain largely unknown. Thus, the mechanisms of exosomes lncRNA PCAT1 were investigated. The expressions of exosomes lncRNA PCAT1 in tissues from stage 0-I and stage II-III CRC patients, and intestinal epithelial cell line FHC and two CRC cell lines, HT29 and HCT8 were measured by real-time quantitative PCR. The effects of lncRNA PCAT1 on adhesion and invasion of two CRC cell lines were investigated by cell-matrix adhesion and transwell assays. In addition, the target of PCAT1 (ZNF217) was validated using an RNA immune precipitation assay. Finally, the protein levels of MTA2, MTA3, SNAI1, and E-cadherin in normal participants, stage 0-I and stage II-III CRC patients, as well as two cell lines with stable ZNF217 knockdown were investigated by western blotting. The plasma exosomal lncRNA PCAT1 was found to be significantly increased in the CRC tissues and cell lines. In addition, lncRNA PCAT1 knockdown significantly inhibited the adhesion and invasion of HT29 and HCT8 cells. RIP assay results showed lncRNA PCAT1 could target ZNF217, and downregulation of lncRNA PCAT1 could decrease the protein expressions of ZNF217 in two CRC cells lines. Moreover, ZNF217 knockdown significantly decreased MTA2, MTA3, and SNAI1 expressions, but increased E-cadherin expressions in both CRC cells lines. Exosomal lncRNA PCAT1 can promote the adhesion and invasion of CRC cells, and PCAT1 overexpression may lead to ZNF217 upregulation that regulates EMT-related MTA2/MTA3/Snai1/E-cadherin signaling.

LncRNA PCAT6 activated by SP1 facilitates the progression of breast cancer by the miR-326/LRRC8E axis.

Breast cancer is an aggressive malignancy with high morbidity in females worldwide. Extensive studies reveal that long noncoding RNAs (lncRNAs) are abnormally expressed and act as key regulators in various cancers, including breast cancer. In this work, we investigated the role and regulatory mechanism of lncRNA prostate cancer-associated transcript 6 (PCAT6) in breast cancer progression. Our findings revealed that PCAT6 was overexpressed in breast cancer tissues and cell lines. Furthermore, elevation of PCAT6 reflected an adverse prognosis of patients. Functional experiments indicated that PCAT6 knockdown hampered cell proliferation, facilitated apoptosis and cell cycle arrest in vitro, and inhibited tumor growth in vivo. We also found that the transcription factor SP1 could bind to the PCAT6 promoter and promoted its expression. Subsequently, it was verified that PCAT6 was a molecular sponge for microRNA-326 (miR-326), and the leucine-rich repeat containing the eight family member E (LRRC8E) was a direct target of miR-326. Rescue assays revealed that LRRC8E overexpression attenuated the suppressive effect of PCAT6 knockdown on cellular progression of breast cancer. In summary, this study demonstrated that SP1-activated PCAT6 promoted the malignant behaviors of breast cancer cells by regulating the miR-326/LRRC8E axis.

M6 A modification of lncRNA PCAT6 promotes bone metastasis in prostate cancer through IGF2BP2-mediated IGF1R mRNA stabilization.

BackgroundBone metastasis is the leading cause of tumor‐related death in prostate cancer (PCa) patients. Long noncoding RNAs (lncRNAs) have been well documented to be involved in the progression of multiple cancers. Nevertheless, the role of lncRNAs in PCa bone metastasis remains largely unclear.MethodsThe expression of prostate cancer‐associated transcripts was analyzed in published datasets and further verified in clinical samples and cell lines by RT‐qPCR and in situ hybridization assays. Colony formation assay, MTT assay, cell cycle analysis, EdU assay, Transwell migration and invasion assays, wound healing assay, and in vivo experiments were carried out to investigate the function of prostate cancer‐associated transcript 6 (PCAT6) in bone metastasis and tumor growth of PCa. Bioinformatic analysis, RNA pull‐down, and RIP assays were conducted to identify the proteins binding to PCAT6 and the potential targets of PCAT6. The therapeutic potential of targeting PCAT6 by antisense oligonucleotides (ASO) was further explored in vivo.Results PCAT6 was upregulated in PCa tissues with bone metastasis and increased PCAT6 expression predicted poor prognosis in PCa patients. Functional experiments found that PCAT6 knockdown significantly inhibited PCa cell invasion, migration, and proliferation in vitro, as well as bone metastasis and tumor growth in vivo. Mechanistically, METTL3‐mediated m6A modification contributed to PCAT6 upregulation in an IGF2BP2‐dependent manner. Furthermore, PCAT6 upregulated IGF1R expression by enhancing IGF1R mRNA stability through the PCAT6/IGF2BP2/IGF1R RNA‐protein three‐dimensional complex. Importantly, PCAT6 inhibition by ASO in vivo showed therapeutic potential against bone metastasis in PCa. Finally, the clinical correlation of METTL3, IGF2BP2, IGF1R, and PCAT6 was further demonstrated in PCa tissues and cells.ConclusionsOur study uncovers a novel molecular mechanism by which the m6A‐induced PCAT6/IGF2BP2/IGF1R axis promotes PCa bone metastasis and tumor growth, suggesting that PCAT6 may serve as a promising prognostic marker and therapeutic target against bone‐metastatic PCa.

LncRNA PCAT6 facilitates cell proliferation and invasion via regulating the miR-326/hnRNPA2B1 axis in liver cancer.

Liver cancer is one of the most common malignant human tumors with the highest morbidity and mortality rates of all cancer types in China. Evidence suggests that long non-coding RNA prostate cancer-associated transcript 6 (PCAT6) plays an essential role in tumor progression. However, the roles and mechanism of PCAT6 in liver cancer remain unclear. The present study showed that the expression of PCAT6 and heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1) was upregulated in liver cancer tissues compared with non-cancerous tissues and were associated with poor overall survival time, whereas microRNA (miR)-326 expression was downregulated. Moreover, knockdown of PCAT6 significantly inhibited the proliferation and invasion of liver cancer cells in vitro and in vivo. A dual-luciferase reporter gene assay demonstrated that PCAT6 could bind to miR-326 and that hnRNPA2B1 was a direct target gene of miR-326. Mechanistically, silenced PCAT6 suppressed the malignant phenotype of liver cancer cells through upregulating the inhibitory effect of miR-326 on hnRNPA2B1 expression. Taken together, these data demonstrated that knockdown of PCAT6 inhibited liver cancer progression through regulation of the miR-326/hnRNPA2B1 axis, suggesting that PCAT6 functions as an oncogene and may be a useful biomarker for the future diagnosis and treatment of liver cancer.

LncRNA PCAT1 Interacts with DKC1 to Regulate Proliferation, Invasion and Apoptosis in NSCLC Cells via the VEGF/AKT/Bcl2/Caspase9 Pathway

Long noncoding RNAs (lncRNAs) are increasingly recognized as indispensable components of the regulatory network in the progression of various cancers, including nonsmall cell lung cancer (NSCLC). The lncRNA prostate cancer associated transcript 1 (PCAT1) has been involved in tumorigenesis of multiple malignant solid tumors, but it is largely unknown that what is the role of lncRNA-PCAT1 and how it functions in the progression of lung cancer. Herein, we observed that lncRNA PCAT1 expression was upregulated in both human NSCLC tissues and cell lines, which was determined by qualitative polymerase chain reaction analysis. Then, gain-and loss-of-function manipulations were performed in A549 cells by transfection with a specific short interfering RNA against PCAT1 or a pcDNA-PCAT1 expression vector. The results showed that PCAT1 not only promoted NSCLC cell proliferation and invasion but also inhibited cell apoptosis. Bioinformatics and expression correlation analyses revealed that there was a potential interaction between PCAT1 and the dyskerin pseudouridine synthase 1 (DKC1) protein, an RNA-binding protein. Then, RNA pull-down assays with biotinylated probes and transcripts both confirmed that PCAT1 directly bounds with DKC1 that could also promote NSCLC cell proliferation and invasion and inhibit cell apoptosis. Moreover, the effects of PCAT1 and DKC1 on NSCLC functions are synergistic. Furthermore, PCAT1 and DKC1 activated the vascular endothelial growth factor (VEGF)/protein kinase B (AKT)/Bcl-2/caspase9 pathway in NSCLC cells, and inhibition of epidermal growth factor receptor, AKT, or Bcl-2 could eliminate the effect of PCAT1/DKC1 co-overexpression on NSCLC cell behaviors. In conclusion, lncRNA PCAT1 interacts with DKC1 to regulate proliferation, invasion, and apoptosis in NSCLC cells via the VEGF/AKT/Bcl-2/caspase9 pathway.

Long non‑coding RNA PCAT6 promotes the development of osteosarcoma by increasing MDM2 expression.

Osteosarcoma is a severe malignant tumor. Several studies indicated that lncRNA prostate cancer-associated transcript 6 (PCAT6) promoted the development of multiple types of cancers. Studies have also revealed that MDM2 could aggravate tumor symptoms inhibiting P53 expression. However, whether lncRNA PCAT6 could affect the proliferation and metastasis of osteosarcoma cells by regulating P53 expression is unclear. The present study established lncRNA PCAT6-overexpressing osteosarcoma cells. Cell Counting Kit-8, wound healing and Transwell assays were performed to detect the change in proliferation, migration and invasion of these cells, respectively. Subsequently, E3 ubiquitin-protein ligase Mdm2 (MDM2), P53 and P21 expression were determined using western blotting. Finally, MDM2 expression was inhibited and the proliferation, migration and invasion of these cells was determined again. The present study found that the proliferation, migration and invasion of osteosarcoma cells increased following overexpression of lncRNA PCAT6. MDM2 expression was upregulated while the levels of P53 and P21 decreased following overexpression of lncRNA PCAT6. However, the proliferation, migration and invasion of osteosarcoma cells were inhibited following MDM2 knockdown. Additionally, P53 and P21 was rescued following MDM2 knockdown. To conclude, lncRNA PCAT6 promoted the proliferation, migration and invasion of osteosarcoma cells by promoting the expression of MDM2 and suppressing the expression of P53 and P21.

LncRNA PCAT6 aggravates the progression of bladder cancer cells by targeting miR-513a-5p.

Long non-coding RNAs (lncRNAs) have been demonstrated to play critical roles in tumorigenesis of bladder cancer (BC). Our research aimed to explore the underlying mechanisms of lncRNA prostate cancer-associated transcript 6 (PCAT6) in BC. Real Time-quantitative Polymerase Chain reaction (RT-qPCR) was used to measure the levels of PCAT6 and miR-513a in BC tissues and cells. The Kaplan-Meier analysis was utilized to evaluate the overall survival time of BC patients. Besides, cell viability was detected by Cell Counting Kit-8 (CCK-8) assay. Cell migration and invasion were evaluated by wound healing and transwell assays. Furthermore, starBase and Dual-Luciferase reporter assay were used to determine the interaction between PCAT6 and miR-513a in BC cells. PCAT6 expression was upregulated, while miR-513a was downregulated in BC tissues and cell lines. BC patients with high expression of PCAT6 exhibited a shorter overall survival time compared with those patients with low expression of PCAT6. Moreover, PCAT6 knockdown notably suppressed cell progression. In addition, PCAT6 inhibited miR-513a expression through direct interaction, and the silencing of PCAT6 remarkably increased the expression of miR-513a. Finally, the knockdown of miR-513a partly abolished PCAT6 silencing-induced inhibitory effects on BC progression. Our study illustrated that PCAT6 knockdown inhibited cell progression of BC by regulating miR-513a, suggesting that PCAT6 might act as a prognostic biomarker and therapeutic target for BC patients.

M2 macrophage-induced lncRNA PCAT6 facilitates tumorigenesis and angiogenesis of triple-negative breast cancer through modulation of VEGFR2

As a common female malignancy, triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancers (BC). This study further studied the role of long noncoding RNA (lncRNA) prostate cancer-associated transcript 6 (PCAT6) in TNBC. Functional assays, including EdU, wound healing, transwell, and immunofluorescence staining, revealed the effect of PCAT6 on cell proliferation, migration, and EMT process. The tube-formation assay disclosed the function of PCAT6 on angiogenesis. In vivo assays were also established to explore the impact of PCAT6 on tumor growth and microangiogenesis. The results revealed that PCAT6 boosted TNBC cell proliferation, migration, and angiogenesis both in vitro and in vivo. Then, this study unveiled that M2 macrophage secreted VEGF to stimulate the upregulation of PCAT6, thus promoting angiogenesis in TNBC. Next, through bioinformatics analysis and mechanism assays, we identified that PCAT6 positively regulated VEGFR2 expression via ceRNA pattern and then participated in VEGFR/AKT/mTOR signaling pathway to accelerate angiogenesis. Moreover, PCAT6 bound USP14, a deubiquitinase, to induce the deubiquitination of VEGFR2. On the whole, M2 macrophage-induced upregulation of PCAT6 facilitates TNBC tumorigenesis through modulation of VEGFR2 expression via ceRNA and deubiquitination patterns.

LncRNA PCAT6 promotes the proliferation, migration and invasion of pancreatic ductal adenocarcinoma via regulating miR-185-5p/CBX2 axis

Emerging evidence has revealed markedly roles for long noncoding RNAs (lncRNAs) in various cancer processes. Prostate cancer associated transcript 6 (PCAT6) is a novel lncRNA which displays vital regulatory functions in multiple cancers. However, the functions of PCAT6 in pancreatic ductal adenocarcinoma (PDAC) remain unclear. Our study confirmed that PCAT6 expression was upregulated in PDAC and the expression of PCAT6 was related to TNM stage, lymph node invasion and overall survival of PDAC patients. PCAT6 might act as an effective tumor biomarker for PDAC patients. Moreover, knockdown of PCAT6 inhibited cell proliferation, migration and invasion of PDAC in vitro. For the mechanism, miR-185-5p expression was decreased and chromobox 2 (CBX2) expression was increased in PDAC, and further PCAT6 could upregulated the expression of oncogene CBX2 by sponging miR-185-5p. The results above suggested that PCAT6/miR-185-5p/CBX2 exerted crucial functions in tumorigenesis and progression of PDAC.

Sevoflurane Inhibits Proliferation, Invasion, but Enhances Apoptosis of Lung Cancer Cells by Wnt/β-catenin Signaling via Regulating lncRNA PCAT6/miR-326 Axis.

Sevoflurane was frequently used as a volatile anesthetic in cancer surgery. However, the potential mechanism of sevoflurane on lung cancer remains largely unclear. In this study, lung cancer cell lines (H446 and H1975) were treated by various concentrations of sevoflurane. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assessment and colony formation assay were performed to detect the cell viability and proliferation, separately. Also, transwell assay or flow cytometry assay was applied as well to evaluate the invasive ability or apoptosis in lung cancer cells, respectively. Western blot assay was employed to detect the protein levels of β-catenin and Wnt5a. Moreover, quantitative real-time polymerase chain reaction (qRT-PCR) was used to examine the expression level of prostate cancer-associated transcript 6 (PCAT6) and miR-326 in lung cancer tissues and cells. The target interaction between miR-326 and PCAT6 or Wnt5a was predicted by bioinformatics analysis and verified by the dual-luciferase reporter gene assay. Sevoflurane inhibited the abilities on viability, proliferation, invasion, and activation of Wnt/β-catenin signaling, but promoted apoptosis of H446 and H1975 cells in a dose-dependent manner. The expression of PCAT6 was increased in lung cancer tissues and cells, except for that of miR-326. Besides, sevoflurane could lead to expressed limitation of PCAT6 or improvement of miR-326. This process presented a stepwise manner. Up-regulation of PCAT6 restored the suppression of sevoflurane on abilities of proliferation, invasion, rather than apoptosis, and re-activated the Wnt5a/β-catenin signaling in cells. Moreover, the putative binding sites between miR-326 and PCTA6 or Wnt5a were predicted by starBase v2.0 software online. PCAT6 suppressing effects on cells could be reversed by pre-treatment with miR-326 vector. The promotion of Wnt5a inverted effects led from miR-326 or sevoflurane. Our study indicated that sevoflurane inhibited the proliferation, and invasion, but enhanced the apoptosis in lung cancer cells by regulating the lncRNA PCAT6/miR-326/Wnt5a/β-catenin axis.

Knockdown of long non-coding RNA prostate cancer-associated transcript 1 inhibits the proliferation and metastasis of tongue squamous cell carcinoma cells by upregulating p21.

Long non-coding RNA (lncRNA) prostate cancer-associated transcript 1 (PCAT-1) is a long non-coding RNA involved in the development of various cancer types. Tongue squamous cell carcinoma (TSCC) is the most frequently diagnosed type of oral cancer worldwide. The present study aimed to explore the role of lncRNA PCAT-1 in TSCC, and to provide a preliminary assessment of the downstream pathways involved. The expression levels of lncRNA PCAT-1 in TSCC specimens were first assessed. Subsequently, lncRNA PCAT-1 was knocked down in TSCC cell lines and the resulting effect on the proliferation and apoptosis, as well as the metastatic and invasive potential of TSCC cells was investigated. To assess the downstream signaling resulting from lncRNA PCAT-1 inhibition, the expression of p21 was also detected. The results indicated that lncRNA PCAT-1 was upregulated in clinical TSCC compared with peri-tumor tissues. Inhibition of lncRNA PCAT-1 resulted in reduced proliferation and apoptosis of TSCC cells, in addition to the suppression of migration and invasion. Furthermore, the expression of p21 was induced following lncRNA PCAT-1 inhibition. Collectively, the present study demonstrated an oncogenic role for lncRNA PCAT-1 in TSCC; inhibition of lncRNA PCAT-1 reduced the growth, metastasis and invasion of TSCC, at least in part via the induction of p21 signaling.

LncRNA PCAT6 Accelerates the Progression and Chemoresistance of Cervical Cancer Through Up-Regulating ZEB1 by Sponging miR-543.

BackgroundCervical cancer (CC) is a common cancer with a poor prognosis due to the chemoresistance of CC cells to cisplatin. This study aimed to investigate the biological significance of lncRNA prostate cancer-associated transcript 6 (PCAT6) in the carcinogenesis of CC.Materials and MethodsQuantitative real-time polymerase chain reaction (qRT-PCR) was carried out to measure the abundance of PCAT6, miR-543 and zinc finger E-box binding protein 1 (ZEB1) in CC tissues and cells. The combination between miR-543 and lncRNA PCAT6 or ZEB1 was predicted by Starbase and was verified by dual-luciferase reporter assay, RNA-pull down assay and RNA immunoprecipitation (RIP) assay. Cell proliferation and chemoresistance to cisplatin were detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell apoptosis and metastasis were determined by flow cytometry, Western blot and transwell migration and invasion assays.ResultsThe abundance of ZEB1 protein was measured by Western blot assay. Murine xenograft model was established to confirm the function of lncRNA PCAT6 in vivo. The abundance of lncRNA PCAT6 was enhanced in CC tissues and cells compared with that in corresponding normal tissues and normal cervical epithelial cells Ect1/E6E7. MiR-543 was a target of PCAT6 and was negatively regulated by PCAT6. PCAT6 accelerated the proliferation, metastasis and the chemoresistance of CC cells to cisplatin while suppressed the apoptosis of CC cells. The overexpression of PCAT6 reversed the inhibitory effects of miR-543 accumulation on the proliferation, metastasis and chemoresistance of CC cells to cisplatin and the promoting impact on the apoptosis of CC cells. ZEB1 was a direct target of miR-543, and it functioned as the downstream gene of PCAT6/miR-543 to exert its oncogenic role in CC. PCAT6 promoted the growth of murine xenograft tumor through miR-543/ZEB1 axis in vivo.ConclusionLncRNA PCAT6 facilitated the proliferation, metastasis and chemoresistance of CC cells to cisplatin while impeded the apoptosis of CC cells via PCAT6/miR-543/ZEB1 axis. PCAT6/miR-543/ZEB1 axis might be a promising target for CC therapy.

Expression of prostate cancer-associated transcript 6 in serum of patients with liver cancer and the effect of its interference on biological function of liver cancer cells

Objective To investigate the expression of prostate cancer-associated transcript 6 (PCAT6) in the serum of hepatocarcinoma patients and its effect on the proliferation, migration, invasion and apoptosis of Hep3B cells. Methods The qPCR method was used to detect the level of long non-coding RNA (lncRNA) PCAT6 in serum and THLE-3, Hep3B and HepG2 cells. The Hep3B cells were randomly divided into blank control group (NC group), negative empty vector transfection group (si-con group) and lncRNA PCAT6 silencing group (si-PCAT6 group). Western blotting was used to detect the expression of matrix metalloproteinase (MMP)-2, MMP-9, cleaved cysteinyl aspartate-specific protease (Caspase)-3, cleaved Caspase-9, phosphatidylinositol 3 kinase (PI3K), phosphorylated-PI3K (p-PI3K), protein kinase B (Akt), and phosphorylated Akt (p-Akt) proteins. The cell proliferation was measured by methyl thiazol tetrazolium (MTT) assay. The apoptosis was examined by flow cytometry, and the migration and invasion was tested detected by Transwell chamber method. The SPSS 21.0 software was used for statistical analysis, and the measurement data were expressed as mean±standard deviation (SD). Results The expression level of lncRNA PCAT6 in patients with moderate or high differentiation (60.94%) was significantly higher than that in patients with low differentiation (6.25%) (χ2=22.968, P<0.01). The percentage of patients with high expression of lncRNA PCAT6 in T-stage Ⅱ-Ⅳ (57.81%) was significantly higher than that in stage Ⅰ (9.38%) (χ2=8.529, P<0.01). The expression of lncRNA PCAT6 in Hep3B cells (3.72±0.67) and HepG2 cells (3.38±0.53) was significantly higher than that in THLE-3 cells (1.03±0.14) (t=9.322 and 8.144, P<0.05). The expression of lncRNA PCAT6 (0.21±0.11) in si-PCAT6 group was significantly lower than that in si-CON group (0.96±0.15) (t=9.915, P<0.05), and the cell viability was significantly reduced at 24 h, 48 h and 72 h (t=3.280, 6.144 and 6.373, P<0.05). Western blotting showed that the expression of cleaved Caspase-3, cleaved Caspase-9, p-pi3k and p-Akt increased significantly (t=11.408, 14.628, 8.683 and 9.585, P<0.01), and the expression of MMP-2 and MMP-9 decreased significantly in si-PCAT6 group (t=10.568 and 10.814, P<0.01). The apoptosis rate of Hep3B cells increased significantly (t=21.075, P<0.01), and the migration and invasion of Transwell cells decreased significantly (t=12.816 and 12.707, P<0.01). Conclusion The serum lncRNA PCAT6 is highly expressed in HCC patients, which is related to the degree of HCC differentiation and T stage. Silencing lncRNA PCAT6 can inhibit the biological behaviors of HCC probably by inhibiting the Akt signaling pathway activation. Key words: Long non-coding RNA; Prostate cancer-associated transcript 6; Liver cancer; Biological function

LncRNA PCAT-1 Promoted ESCC Progression via Regulating ANXA10 Expression by Sponging miR-508-3p.

BackgroundGiven the poor prognosis of metastatic esophageal squamous cell carcinoma (ESCC) patients, molecular mechanisms underlying the progression and metastasis of ESCC are highly desired in the scientific community. Prostate cancer associated transcript-1 (PCAT-1) is a lncRNA up-regulated in major types of cancers and is associated with the poor prognosis of cancer patients. This study aimed to understand the expression and role of PCAT-1 in the progression and metastasis of ESCC and to identify the potential lncRNA-miRNA interactions and signaling pathways underlying the mechanisms of action of PCAT-1 in ESCC.Materials and MethodsGene expression levels were determined by qRT-PCR; protein levels were determined by Western blot assay; cell proliferation, invasion and migration were determined by CCK-8, Transwell invasion and wound healing assays, respectively; in vivo tumor growth was evaluated by xenograft nude mice model.ResultsOur data showed the up-regulation of PCAT-1 in different human ESCC cell lines and in clinical ESCC tissues. Knockdown of PCAT-1 in ESCC cells significantly inhibited the proliferation, invasion and migration of the cancer cells. Moreover, we showed the interactions between PCAT-1 and miR-508-3p and demonstrated that PCAT-1 was able to repress miR-508-3p expression in ESCC cells via acting as a competing endogenous RNA. Besides, Annexin A10 (ANXA10) was identified to be the downstream target of the PCAT-1 and miR-508-3p interactions.ConclusionThis study demonstrated the functional role of PCAT-1 in promoting the proliferation, invasion and migration of ESCC cells. We also identified a PCAT-1/miR-508-3p/ANXA10 axis in mediating the promoting role of PCAT-1 in the progression of ESCC. The findings provide experimental evidence to support lncRNA PCAT-1 as a potential therapeutic target of ESCC.

LncRNA PCAT-1 upregulates RAP1A through modulating miR-324-5p and promotes survival in lung cancer.

IntroductionLung cancer is the malignant tumor with the fastest increase in morbidity and mortality and the greatest threat to human health and life. Long non-coding RNA (lncRNA) is emerging as an important regulator in many cancers. Recently, it was found that lncRNA prostate cancer associated transcript 1 (PCAT-1) was up-regulated in lung cancer, playing oncogenic roles. However, the underlying regulatory mechanism of PCAT-1 remains unknown.Material and methodsThe expression levels of PCAT-1 and miR-324-5p were analyzed by real-time PCR, and RAP1A expression was determined by western blotting. RNA pull-down, luciferase and western blotting assays were used to examine the target relationship between PCAT-1 and miR-324-5p or that between miR-324-5p and RAP1A. The functional effects of PCAT-1 and miR-324-5p were examined using cell viability and cell apoptosis assays.ResultsPCAT-1 overexpression remarkably promoted cell proliferation and suppressed cell apoptosis. Mechanistic investigations demonstrated that PCAT-1 can interact with miR-324-5p and repress its expression, thereby increasing the expression of its target RAP1A. Additionally, rescue experiments revealed that PCAT-1 served as an oncogene partly through sponging miR-324-5p and upregulating RAP1A in lung cancer cells.ConclusionsOur findings demonstrate that on account of the dual function of pro-proliferation and anti-apoptosis, PCAT-1/miR-324-5p/RAP1A may be novel candidates for application in the diagnosis, prognosis and therapy of lung cancer.

Biological and Clinical Relevance of Long Non-Coding RNA PCAT-1 in Cancer, A Systematic Review and Meta-Analysis

Long non-coding RNA (lncRNA) prostate cancer associated transcript 1 (PCAT-1) has been identified as a potential biomarker for the diagnosis and prognosis of various cancers. We performed this systematic review and meta-analysis to evaluate the role of dysregulation as well as the biological and clinical significance of lnc-PCAT-1 for predicting the malignancy status in several cancers. Two independent reviewers conducted an extensive search in electronic databases of Medline, Embase, Scopus, Web of Science and PubMed until the December of 2017. Five articles investigating the clinical significance of lncRNA PCAT-1, including 996 patients, were analyzed. Our results revealed that the increased PCAT-1 expression was related to overall survival (OS) (HR = 1.9, 95% CI: 1.13-3.18, P=0.015). Also, pooled results of the diagnostic data analysis demonstrated that PCAT-1 has a sensitivity of 0.59 and specificity of 0.66 for cancer diagnosis. Moreover, pooled area under curve was 0.62 (95% CI: 0.58–0.69). This meta-analysis revealed that lncRNA PCAT-1 could be served as a potential diagnostic and prognostic biomarker in various solid tumors.

LncRNA PCAT6 promotes non-small cell lung cancer cell proliferation, migration and invasion through regulating miR-330-5p.

BackgroundInvestigating the roles of lncRNA prostate cancer-associated transcript 6 (PCAT6) in modulating the growth and aggressiveness of non-small-cell lung carcinoma (NSCLC) cell.MethodThe levels of PCAT6 in NSCLC tissues and cell lines were determined by quantitative real-time PCR assay. MTT as well as colony formation assays were applied to explore the effect of PCAT6 on the growth of NSCLC cell in vitro. Wound healing and Transwell assays were utilized to analyze the impact of PCAT6 on the migration and invasion of NSCLC cell. Bioinformatics analysis and luciferase reporter assay were used to prove that miR-330-5p was the target of PCAT6. Colony formation, wound healing, and Transwell invasion assays were applied to demonstrate that PCAT6 promoted NSCLC cell growth, migration, and invasion through binding miR-330-5p. Finally, xenograft model was used to explore the role of PCAT6 in the tumor growth of NSCLC cell in vivo.ResultsPCAT6 was highly overexpressed in NSCLC tissues and cells compared with normal tissues and non-tumorigenic bronchial epithelial cell line, BEAS-2B. Downregulation of PCAT6 markedly reduced the proliferation, migration, and invasion of NSCLC cell. Moreover, down-expression of PCAT6 significantly increased the level of miR-330-5p in NSCLC cell. Further functional experiments indicated that down-expression of miR-330-5p reversed the inhibitory effect of PCAT6 on NSCLC cell growth, migration, and invasion.ConclusionOur results reveal that lncRNA PCAT6 facilitates the proliferation, migration, and invasion of NSCLC cell via competitively binding to miR-330-5p.