The lncRNA PDIA3P Interacts with miR-185-5p to Modulate Oral Squamous Cell Carcinoma Progression by Targeting Cyclin D2

Silencing of long noncoding RNA UCA1 inhibits colon cancer invasion, migration and epithelial-mesenchymal transition and tumour formation by upregulating miR-185-5p in vitro and in vivo

Colon cancer is the third most common malignancy in the world. Long-chain noncoding RNA urothelial carcinoma-associated 1 (UCA1) was abnormally expressed in colon cancer and participated in colon cancer by regulating multiple miRNAs. This study further explored the molecular mechanism of UCA1 in the development of colon cancer from both in vitro and in vivo. The results showed that UCA1 was highly expressed in colon cancer cells, while miR-185-5p was low expressed. Bioinformatics analysis showed that miR-185-5p was a target of UCA1, while MAPK14 was a target of miR-185-5p. Knockdown of UCA1 with shRNA (sh-UCA1) resulted in a significant increase in miR-185-5p and a significant decrease in MAPK14. In addition, sh-UCA1 inhibited invasion, migration and epithelial-mesenchymal transformation of colon cancer cells. Western blotting also showed that sh-UCA1 inactivated the MAPKAPK2/HSP27 pathway. Furthermore, animal studies have revealed that sh-UCA1 inhibited tumour formation in vivo and improved the survival rate of mice. Collectively, these results suggest that silencing UCA1 may inhibit the carcinogenesis and metastasis of colon cancer in vitro and in vivo by modulating miR-185-5p/MAPK14/MAPKAPK2/HSP27 axis. SIGNIFICANCE OF THE STUDY: Colon cancer is the third largest malignant tumour worldwide. This study elucidated the role of urothelial carcinoma-associated 1 (UCA1) in colon cancer cells and its molecular mechanism. The present study suggests that silencing UCA1 may inhibit the invasion, migration, epithelial-mesenchymal transformation and tumour formation of colon cancer by upregulating miR-185-5p in vitro and in vivo. In summary, this study provides a new strategy for targeted therapy of colon cancer.

lncRNA KLF3-AS1 Suppresses Cell Migration and Invasion in ESCC by Impairing miR-185-5p-Targeted KLF3 Inhibition

Esophageal squamous cell carcinoma (ESCC) is a common cancer occurring in males and females worldwide. Accumulating evidence continues to highlight the crucial roles of long non-coding RNAs (lncRNAs) in the process of tumorigenesis. However, the regulatory mechanism of lncRNAs in ESCC remains unclear. The aim of this study is to elucidate the role of lncRNA Krüppel-like factor 3 antisense RNA 1 (KLF3-AS1) in ESCC by regulating miR-185-5p and KLF3. Initially, ESCC cell spheres with stem cell-like properties were prepared by suspension culture, and subsequently characterized by assessing colony formation ability and stem cell markers. LncRNA KLF3-AS1 was found to be poorly expressed in ESCC and could upregulate the expression of KLF3 by binding to miR-185-5p. lncRNA KLF3-AS1 upregulation was observed to inhibit miR-185-5p, thereby contributing to decreased expression of SOX2 and Oct4 (octamer-binding transcription factor 4). Furthermore, enhancement of lncRNA KLF3-AS1 resulted in reduced colony formation ability, cell invasion and migration, and tumor volume in vivo while promoting cell apoptosis in ESCC through downregulation of miR-185-5p. Collectively, this study indicated that lncRNA KLF3-AS1 inhibited ESCC cell invasion and migration by impairing miR-185-5p-mediated inhibition of KLF3, highlighting a promising novel potential target for ESCC treatment.

The Biomarker TCONS_00016233 Drives Septic AKI by Targeting the miR-22-3p/AIFM1 Signaling Axis

The prediction of mortality for septic acute kidney injury (AKI) has been assessed by a number of potential biomarkers, including long noncoding RNAs (lncRNAs). However, the validation of lncRNAs as biomarkers, particularly for the early stages of septic AKI, is still warranted. Our results indicate that the lncRNA TCONS_00016233 is upregulated in plasma of sepsis-associated non-AKI and AKI patients, but a higher cutoff threshold (9.5 × 10⁵, copy number) provided a sensitivity of 71.9% and specificity of 89.6% for the detection of AKI. The plasma TCONS_00016233 was highly correlated with serum creatinine, tissue inhibitor metalloproteinase-2 (TIMP-2), insulin-like growth factor binding protein-7 (IGFBP7), interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), C-reactive protein (CRP), and urinary TCONS_00016233. Lipopolysaccharide (LPS) induced the expression of lncRNA TCONS_00016233 via the Toll-like receptor 4 (TLR4)/p38 mitogen-activated protein kinase (MAPK) signal pathway in human renal tubular epithelial (HK-2) cells. Furthermore, TCONS_00016233 mediates the LPS-induced HK-2 cell apoptosis and the expression of IL-1β and TNF-α. Mechanistically, TCONS_00016233 acts as a competing endogenous RNA (ceRNA) to prevent microRNA (miR)-22-3p-mediated downregulation of the apoptosis-inducing factor mitochondrion-associated 1 (AIFM1). Finally, overexpression of TCONS_00016233 is capable of aggravating the LPS- and cecal ligation and puncture (CLP)-induced septic AKI by targeting the miR-22-3p/AIFM1 axis. Taken together, our data indicate that TCONS_00016233 may serve as an early diagnosis marker for the septic AKI, possibly acting as a novel therapeutic target for septic AKI.

FOXD2-AS1 Predicts Dismal Prognosis for Oral Squamous Cell Carcinoma and Regulates Cell Proliferation

The roles of long noncoding RNA FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1) in oral squamous cell carcinoma (OSCC) remain largely unknown. Here, the Atlas of Noncoding RNAs in Cancer online database was utilized to analyze the expression and clinical significance of FOXD2-AS1 in OSCC. Then, the cell proliferation of FOXD2-AS1-silenced OSCC cells (CAL-27) was assessed by MTT and clone formation experiments. FOXD2-AS1-coexpressed genes were enriched and analyzed via circlncRNAnet and Metascape tools. Finally, key molecules of the signal pathways of the aforementioned coexpressed genes were verified by western blotting. We found that FOXD2-AS1 was significantly highly expressed in OSCC tissues, and correlated with poor pathological grade and prognosis in patients with OSCC. Cell viability and clone formation ability were significantly inhibited after the knockdown of FOXD2-AS1. A total of 32 coexpressed genes of FOXD2-AS1 were identified, and those genes were enriched in the cell cycle. In conclusion, FOXD2-AS1 may be served as a potential prognostic indicator and therapeutic target for OSCC.

Long non-coding RNA HOXA11-AS upregulates Cyclin D2 to inhibit apoptosis and promote cell cycle progression in nephroblastoma by recruiting forkhead box P2

Long non-coding RNAs (lncRNAs) have been highlighted to play key roles in the gene regulatory network, and the dysregulation of lncRNAs has also been implicated in various malignancies. However, little is known regarding the expression of lncRNA and their functions in the progression of nephroblastoma. Thus, the present study aimed to explore the potential role of homeobox A11 (HOXA11)-AS in nephroblastoma. Microarray-based analysis was initially applied to screen the differentially expressed lncRNAs, and HOXA11-AS was selected as the candidate. The HFWT cells were performed with gain- and loss-of function test to evaluate the role of HOXA11-AS in cell cycle and apoptosis in nephroblastoma using flow cytometry and Western blots. Moreover, the relationship between HOXA11-AS and forkhead box P2 (FOXP2) was verified by Cross-linking RIP, and the direct interaction between HOXA11-AS and Cyclin D2 (CCND2) was detected using a dual luciferase reporter gene assay. Tumor formation in nude mice was used to investigate the effect of HOXA11-AS in vivo. HOXA11-AS was found to be highly expressed in the nephroblastoma. Furthermore, the silencing of HOXA11-AS promoted apoptosis and cell cycle arrest at the G1/S phase in nephroblastoma through the transcription factor FOXP2 to downregulate the expression of CCND2. Consistently, the tumor formation data in nude mice verified the results in vivo. Taken together, silencing of HOXA11-AS promotes apoptosis and inhibits the cell cycle entry in nephroblastoma by recruiting the transcription factor FOXP2 to downregulate the expression of CCND2, highlighting a promising novel direction for future nephroblastoma treatment.

lncRNA XIST attenuates hypoxia-induced H9c2 cardiomyocyte injury by targeting the miR-122-5p/FOXP2 axis

OBJECTIVE

To investigate the effect of lncRNA XIST on apoptosis induced by hypoxia.

METHODS

We analyzed the expression levels of lncRNA XIST and miR-122-5p using RT-qPCR in hypoxia-induced cardiomyocytes. The mechanism by which lncRNA XIST affects myocardial ischemia was investigated using the cell transfection, CCK-8, and dual-luciferase reporter assays, as well as by flowcytometry, western blotting, and RNA immunoprecipitation.

RESULTS

Hypoxic H9c2 cells demonstrated a decrease in their migration and invasion abilities and XIST expression and an increase in the extent of their apoptosis and expression of microRNA-122-5p. Overexpression of XIST significantly increased the H9c2 cell viability, enhanced cell migration and invasion, and decreased cell apoptosis in a hypoxic environment. The luciferase activity of XIST-WT in H9c2 cells co-transfected with XIST-WT and microRNA-122-5p mimics had decreased. The results of RNA immunoprecipitation showed that XIST interacted directly with miRNA-122-5p. Overexpression of XIST decreased the level of miRNA-122-5p significantly. mi-122-5p mimics increased H9c2 cell apoptosis and downregulated FOXP2 expression. Overexpression of FOXP2 upregulated the expression of the Bcl-2 protein in H9c2 cells transfected with microRNA-122-5p mimics and inhibited the expression of HIF-alpha, Bax, and the cleaved-caspase 9 protein.

CONCLUSION

lncRNA XIST could regulate the miR-122-5p/FOXP2 axis to attenuate hypoxia-induced H9c2 cardiomyocyte injury.

Delivery of mesenchymal stem cells-derived extracellular vesicles with enriched miR-185 inhibits progression of OPMD

Oral leukoplakia is one of the most common oral potentially malignant disorders (OPMDs) and its malignant transformation to oral cancer is highly associated with chronic inflammation. Extracellular vesicles (EVs) or exosome-delivered microRNAs modulate inflammatory responses and alleviate irritations that predisposes to cancer. We previously reported that microRNA-185 (miR-185) was significantly decreased in the buccal tissue of patients with oral cancer. In this study, we utilized genetically modified mesenchymal stem cells (MSCs) derived EVs with high expression of miR-185 to pasted MSC-EV-miR-185 on buccal lesions in dimethylbenzanthracene (DMBA) induced OPMD model. We found that treatment with MSC-EV-miR-185 remarkably attenuated inflammation severity and significantly decreased the incidence and the number of dysplasia in the OPMD tissue. Immunohistochemistry showed significantly decreased expression of proliferation marker PCNA and angiogenic marker CD31 in the lesion treated with MSC-EV-miR-185. Furthermore, miR-185 specifically targeted Akt genes by promoting activation of the apoptotic pathway, confirmed by the increased levels of activated caspase-3 and 9. In conclusion, genetically modified MSC-derived EVs enriched with miR-185 alleviate inflammatory response, inhibit cell proliferation and angiogenesis, and induce cell apoptosis, suggesting that their potential role as a novel therapeutic option for OPMD.

KCNQ1OT1 promotes migration and inhibits apoptosis by modulating miR-185-5p/Rab14 axis in oral squamous cell carcinoma

Long non-coding RNAs (lncRNAs) play essential roles in the regulation of gene transcription in carcinogenesis and metastasis via interacting with microRNA. In this study, we explored the expressions and functions of lncRNA KCNQ1OT1 and miR-185-5p in oral squamous cell carcinoma (OSCC) cells. KCNQ1OT1 expression in OSCC tissues and cells was examined by qRT-PCR. Small interfering RNAs against KCNQ1OT1 (si- KCNQ1OT1) were used to knockdown KCNQ1OT1 in OSCC cells. Cell function was assessed by wound healing assay, transwell assay, and apoptosis detection. The binding region between KCNQ1OT1 and miR-185-5p was confirmed by luciferase assays. MiR-185-5p expression was measured by qRT-PCR. Rab14 was confirmed as a downstream target gene of miR-185-5p by measuring luciferase activities. The protein level of Rab14 in OSCC cells transfected with miR-185-5p or si-KCNQ1OT1 was determined by Western blot. The OSCC cell function and Rab14 expression after co-transfection of si-KCNQ1OT1 and miR-185-5p inhibitor were also examined. KCNQ1OT1 was upregulated in OSCC tissues and cells. KCNQ1OT1 silencing suppressed OSCC cell malignancy and downregulated miR-185-5p level, which showed upregulated expression in OSCC samples. Rab14 as a target gene of miR-185-5p was highly expressed in OSCC. KCNQ1OT1 knockdown impaired the invasion capability of OSCC cells, promoted apoptosis, and suppressed Rab14 expression. The inhibition of miR-185-5p in KCNQ1OT1 silencing cells reversed the suppression of Rab14 and restored the cancerous growth of OSCC cells. These results indicated that KCNQ1OT1 promoted OSCC tumorigenesis via the modulation of miR-185-5p/Rab14 axis, which may serve as a therapeutic target for the treatment of OSCC.

PICOT binding to chromatin-associated EED negatively regulates cyclin D2 expression by increasing H3K27me3 at the CCND2 gene promoter

Protein kinase C (PKC)-interacting cousin of thioredoxin (PICOT; also termed glutaredoxin 3 (Grx3; Glrx3)) is a ubiquitous protein that can interact with the embryonic ectoderm development (EED) protein via each of its two C-terminal PICOT/Grx homology domains. Since EED is a Polycomb-Group protein and a core component of the polycomb repressive complex 2 (PRC2), we tested the involvement of PICOT in the regulation of PRC2-mediated H3 lysine 27 trimethylation (H3K27me3), transcription and translation of selected PRC2 target genes. A fraction of the cellular PICOT protein was found in the nuclei of leukemia cell lines, where it was associated with the chromatin. In addition, PICOT coimmunoprecipitated with chromatin-residing EED derived from Jurkat and COS-7 cell nuclei. PICOT knockdown led to a reduced H3K27me3 mark and a decrease in EED and EZH2 at the CCND2 gene promoter. In agreement, PICOT-deficient T cells exhibited a significant increase in CCND2 mRNA and protein expression. Since elevated expression levels of PICOT were reported in several different tumors and correlated in the current studies with decreased transcription and translation of the CCND2 gene, we tested whether this opposite correlation exists in human cancers. Data from the Cancer Genome Atlas (TCGA) database indicated statistically significant negative correlation between PICOT and CCND2 in eight different human tumors where the highest correlation was in lung (p = 8.67E−10) and pancreatic (p = 1.06E−5) adenocarcinoma. Furthermore, high expression of PICOT and low expression of CCND2 correlated with poor patient survival in five different types of human tumors. The results suggest that PICOT binding to chromatin-associated EED modulates the H3K27me3 level at the CCND2 gene promoter which may be one of the potential mechanisms for regulation of cyclin D2 expression in tumors. These findings also indicate that a low PICOT/CCND2 expression ratio might serve as a good predictor of patient survival in selected human cancers.

Long noncoding RNA LINC00958 promotes the oral squamous cell carcinoma by sponging miR-185-5p/YWHAZ

AIM

Increasing evidence has indicated the essential roles of long noncoding RNA (lncRNA) in the oral squamous cell carcinoma (OSCC). However, there are still numerous uncertain mechanisms for the pathophysiological process of OSCC. In this work, we tried to identify the biological function and potential mechanism of lncRNA LINC00958 in the OSCC.

MAIN METHODS

The expressions of RNA and protein were measured by quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting. The tumor behavior was detected using the CCK-8 assay, transwell assay, flow cytometry assay and xenograft in vivo assay. The interaction within LINC00958/miR-185-5p/YWHAZ was identified using the luciferase reporter assay.

KEY FINDINGS

LINC00958 expression was remarkably up-regulated in the OSCC tissue and cell lines. Clinical investigation showed that LINC00958 overexpression was associated with poor prognosis, acting as an independent prognostic factor for OSCC. Loss- and gain-of-function assays indicated that LINC00958 promoted the proliferation, invasion and reduced the apoptosis of OSCC cells in vitro. In vivo, knockdown of LINC00958 repressed the tumor growth. Mechanistically, bioinformatic tools and luciferase reporter assay indicated that miR-185-5p both targeted the 3'-UTR of LINC00958 and YWHAZ, constructing the LINC00958/miR-185-5p/YWHAZ regulatory axis.

SIGNIFICANCE

Taken together, the findings in this research reveal the modulation of LINC00958 for the OSCC tumorigenesis through the miR-185-5p/YWHAZ axis, which might be useful for the mechanical investigation associated with OSCC therapeutic target.

lncRNA PDIA3P regulates cell proliferation and invasion in non-small cell lung cancer

Increasing evidence has shown that long non-coding RNAs (lncRNAs) serve a critical role in tumor progression. The lncRNA protein disulfide isomerase family A member 3 pseudogene 1 (PDIA3P) is associated with the progression of oral squamous cell carcinoma and multiple myeloma. However, the roles of lncRNA PDIA3P in non-small cell lung cancer (NSCLC) remain unknown. In the present study, it was demonstrated that lncRNA PDIAP3 expression was significantly increased in patients with NSCLC, particularly in patients with an advanced Tumor-Node-Metastasis stages and lymph-node metastasis. The Gene Expression Profiling Interactive Analysis database revealed that patients with NSCLC with high lncRNA PDIA3P expression had a poorer disease-free survival rate. Furthermore, functional assays suggested that PDIA3P inhibition significantly suppressed the proliferation and invasion of NSCLC cells in vitro and reduced tumor growth in vivo. In addition, lncRNA PDIA3P enhanced the activity of the Wnt/β-catenin pathway in progression of NSCLC. The present study showed that lncRNA PDIA3P promoted NSCLC progression by regulating Wnt/β-catenin signaling, highlighting a potential therapeutic target for treating patients with NSCLC treatment.

lncRNA FOXD2-AS1 confers cisplatin resistance of non-small-cell lung cancer via regulation of miR185-5p-SIX1 axis

Background: Chemoresistance is a major obstacle for chemotherapy failure in non-small-cell lung cancer (NSCLC). lncRNAs are a class of pivotal regulators in various cancers, and the lncRNA FOXD2-AS1 is implicated in the progression of NSCLC. However, it is still unclear whether it regulates chemosensitivity. Methods: Expression levels of FOXD2-AS1, miR185-5p, and SIX1 mRNA were identified by reverse-transcription qPCR. CCK8 assay was performed to assess cell proliferation and chemosensitivity of cisplatin-resistant A549/DDP and H1299/DDP cells. Colony-forming assay was utilized to detect colony numbers. Cell migration and invasion ability were measured by transwell assay. The protein levels of LRP, Pgp, MRP1, and SIX1 were examined by Western blot assay. The correlation between FOXD2-AS1 and miR185-5p or miR185-5p and SIX1 were validated by bioinformatic, dual-luciferase, and RNA immunoprecipitation assays. Tumor xenografts were constructed to confirm the function and mechanism of FOXD2-AS1 in chemosensitivity of DDP-resistant NSCLC. Results: FOXD2-AS1 and SIX1 were upregulated and miR185-5p downregulated in DDP-resistant NSCLC. Absence of FOXD2-AS1 enhanced drug sensitivity of A549/DDP and H1299/DDP cells, reflected by the reduced colony formation, cell proliferation, migration, invasion, and drug resistance-associated protein expression. FOXD2-AS1 acted as a molecular sponge for miR185-5p and relieved the binding of miR185-5p and its target gene SIX1, leading to the derepression of SIX1 in A549/DDP and H1299/DDP cells. Rescue experiments validated the functional interaction among FOXD2-AS1, miR185-5p, and SIX1. Moreover, FOXD2-AS1 interference receded the growth of DDP-resistant NSCLC tumors in vivo. Conclusion: FOXD2-AS1/miR185-5p/SIX1 regulates the progression and chemosensitivity of DDP-resistant NSCLC, suggesting a potential therapeutic target for cisplatin-resistant NSCLC patients.

Long noncoding RNA OIP5-AS1 promotes the progression of oral squamous cell carcinoma via regulating miR-338-3p/NRP1 axis

Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1), a novel identified long noncoding RNA (lncRNA), has been suggested to serve as oncogene in multiple cancers. However, the functional involvement of OIP5-AS1 in oral squamous cell carcinoma (OSCC) was still unknown. The aims of this study were to investigate the functional role of OIP5-AS1 in OSCC and explore its potential mechanism. We found that OIP5-AS1 was up-regulated in OSCC tissues compared with adjacent non-tumor tissues. Loss-of-function experiments revealed that OIP5-AS1 knockdown significantly inhibited OSCC cell proliferation, migration and invasion in vitro, and retarded tumor growth in vivo. Mechanistically, OIP5-AS1 serves as a competing endogenous RNA of miR-338-3p and modulates the expression of neuropilin1 (NRP1), which has been identified as a downstream target gene of miR-338-3p in OSCC. Moreover, downregulation of miR-338-3p or overexpression of NRP1 partly reversed the inhibitory effect of OIP5-AS1 depletion on cell proliferation, migration and invasion. The current results provide evidences for the role of OIP5-AS1 in promoting OSCC progression by regulating miR-338-3p/NRP1 axis and suggest OIP5-AS1 as a potential therapy target for OSCC.

lncRNA NR_038323 Suppresses Renal Fibrosis in Diabetic Nephropathy by Targeting the miR-324-3p/DUSP1 Axis

Several studies have suggested that long intergenic noncoding RNAs are involved in the progression of diabetic nephropathy (DN). However, the exact role and regulatory mechanism of long noncoding RNA (lncRNA) NR_038323 in diabetic nephropathy (DN) remain largely unclear. In the present study, we found that lncRNA NR_038323 overexpression ameliorated the high glucose (HG)-induced expression levels of collagen I, collagen IV, and fibronectin, whereas lncRNA NR_038323 knockdown exerted the opposite effects. Moreover, the results of bioinformatic prediction, luciferase assay, and fluorescence in situ hybridization (FISH) demonstrated that lncRNA NR_038323 directly interacted with miR-324-3p. Additionally, miR-324-3p mimic aggravated the HG-induced expression levels of collagen I, collagen IV, and fibronectin by dual-specificity protein phosphatase-1 (DUSP1) expression to activate p38 mitogen-activated protein kinase (MAPK) and ERK1/2 pathways. In contrast, overexpression of DUSP1 attenuated the HG-induced expression levels of collagen I, collagen IV, and fibronectin via inactivation of p38 MAPK and ERK1/2 pathways. In addition, lncRNA NR_038323 knockdown increased the expression levels of collagen I, collagen IV, and fibronectin by upregulating DUSP1 expression during HG treatment, which were markedly reversed by miR-324-3p inhibitor. Furthermore, these molecular changes were verified in the human kidney samples of DN patients. Finally, overexpression of lncRNA NR_038323 ameliorated the interstitial fibrosis in STZ-induced diabetic nephrology (DN) rat via miR-324-3p/DUSP1/p38MAPK and ERK1/2 axis. In conclusion, our data indicate that overexpression of lncRNA NR_038323 may suppress HG-induced renal fibrosis via the miR-324-3p/DUSP1/p38MAPK and ERK1/2 axis, which provides new insights into the pathogenesis of DN.

Effects of long non-coding RNA (lncRNA) cancer susceptibility candidate 2c (CASC2c) on proliferation, metastasis and drug resistance of non-small cell lung cancer (NSCLC) cells through ERK1/2 and β-catenin signaling pathways

OBJECTIVES

This study was aimed to investigate the effects of long non-coding RNA (lncRNA) cancer susceptibility candidate 2c (CASC2c) on the proliferation, metastasis and drug resistance of non-small cell lung cancer (NSCLC) cells.

METHODS

The expression of CASC2c in NSCLC tissues and cell lines was detected by real-time fluorescence quantitative PCR (RT-qPCR). MTT and Transwell assay were used to determine the proliferation and migration of NSCLC cells in the experimental group and the control group respectively. The drug sensitivity test was used to confirm whether increasing the CASC2c expression level could reverse the resistance of NSCLC cells to the chemotherapy drug cisplatin. The effects of CASC2c on the expression levels of p-ERK1/2 and β-catenin were detected by western blot.

RESULTS

The results of RT-qPCR showed that CASC2c was under-expressed in NSCLC tissues and cells compared with normal adjacent lung tissues cells (p < 0.05). In addition, the CASC2c expression was remarkably correlated with TNM staging, tumor cell differentiation, lymph node metastasis, smoking and other pathological indicators of patients with NSCLC (p < 0.05). MTT and Transwell assay showed that the high-expression of CASC2c significantly reduced the proliferation and migration of NSCLC cells compared to that of the control group (p < 0.05). Western blot assay showed that the high-expressed CASC2c can decrease the expression of phosphorylated-ERK1/2 (p-ERK1/2) and β-catenin.

CONCLUSIONS

CASC2c was low expressed in NSCLC tissues and cells. What's more, it inhibited the proliferation and migration of NSCLC cells by inhibiting the expression of p-ERK1/2 and β-catenin and reversed NSCLC cells' resistance to the chemotherapy drug cisplatin. Therefore, CASC2c may serve as a new biomarker and therapeutic target in the diagnosis and treatment of NSCLC.

LncRNA PLAC2 upregulates p53 to induce hepatocellular carcinoma cell apoptosis

It is known that lncRNA PLAC2 can inhibit glioma. This study explored the function of PLAC2 in hepatocellular carcinoma (HCC). Our data showed that PLAC2 expression in HCC was not affect by HCV and HBV infection, while PLAC2 levels were significantly lower in HCC tissues comparing to non-cancer tissues. Low PLAC2 levels in HCC tissues were associated with low overall 5-year survival rate. P53 mRNA was also downregulated in HCC and positively correlated with PLAC2. PLAC2 overexpression caused upregulated p53 and increase cancer cell apoptosis. P53 overexpression failed to affect PLAC2. In addition, p53 silencing reduced the effects of PLAC2 overexpression. Therefore, PLAC2 upregulated p53 to mediate cancer cell apoptosis.

World Workshop on Oral Medicine VII: Clinical evidence of differential expression of lncRNAs in oral squamous cell carcinoma: A scoping review

BACKGROUND

Long non-coding RNAs (lncRNAs) have important roles in regulating gene expression pertaining to cell proliferation, survival, migration and genomic stability. Dysregulated expression of lncRNAs is implicated in cancer initiation, progression and metastasis.

OBJECTIVES

To explore, map and summarize the extent of evidence from clinical studies investigating the differential expression of lncRNAs in oral/tongue squamous cell carcinoma.

METHODS

PubMed, Scopus and Web of Science were used as search engines. Clinical, full-length, English language studies were included. PRISMA-ScR protocol was used to evaluate and present results. The present scoping review summarizes relationships of the differential expression of lncRNAs with the presence of tumour and with clinicopathological features including survival.

RESULTS

Almost half of the investigated transcripts have been explored in more than one study, yet not always with consistent results. The collected data were also compared to the limited studies investigating oral epithelial dysplasia. Data are not easily comparable, first because of different methods used to define what differential expression is, and second because only a limited number of studies performed multivariate analyses to identify clinicopathological features associated with the differentially expressed lncRNAs.

CONCLUSIONS

Standard methods and more appropriate data analyses are needed in order to achieve reliable results from future studies.

Decreased expression of lncRNA loc285194 as an independent prognostic marker in cancer: A systematic review and meta-analysis

BACKGROUND

Several studies have indicated that lncRNA loc285194 is aberrantly expressed in many types of cancer. This meta-analysis was performed to elucidate the potential role of lncRNA loc285194 as a prognostic marker in malignant tumors.

METHODS

An electronic search of PubMed, Medline, Embase, and Web of Science was performed to identify all eligible papers related to the prognostic impact of lncRNA loc285194 expression in cancer. Hazard ratios (HR) and 95% confidence intervals (CI) were extracted from the included studies to explore the association between lncRNA loc285194 expression and patient overall and disease-free survival (OS & DFS). The odds ratios (ORs) were also calculated to assess the association between lncRNA loc285194 expression and clinicopathological parameters.

RESULTS

A total of 14 eligible articles with 1215 patients were included in this meta-analysis. Meta-results revealed that low expression of lncRNA loc285194 was significantly correlated with poorer overall survival (OS; HR = 2.34; 95% CI, 1.78-3.06; P < 0.001) and disease-free survival (DFS; HR = 2.66; 95% CI, 1.95-3.64; P = 0.001) rates in cancer patients. Low lncRNA loc285194 expression was also found to be significantly associated with lymph node metastasis (LNM; OR = 2.17; 95% CI, 1.23-3.83; P = 0.007), and distant metastasis (DM; OR = 2.49; 95% CI, 1.26-4.91; P = 0.009).

CONCLUSIONS

This study demonstrated that decreased level of lncRNA loc285194 was associated with poor clinical outcomes for patients with different types of cancer, supporting a promising potential biomarker for prognosis and metastasis in human cancers.

Long noncoding RNA PDIA3P promotes breast cancer development by regulating miR-183/ITGB1/FAK/PI3K/AKT/β-catenin signals

Aberrantly expressed long noncoding RNAs (lncRNAs) play crucial roles in the process of breast cancer (BC). This research aims to dig the possible roles and regulatory mechanism of lncRNA protein disulfide isomerase family A member 3 pseudogene 1 (PDIA3P1) in BC. The mRNA level of PDIA3P both in BC tissues and in cells were determined, followed by the investigation of the effects of PDIA3P suppression on cell biological processes including the viability, apoptosis, migration and invasion. Furthermore, whether PDIA3P modulated the expression of integrin β1 (ITGB1) expression by competitively sponging miR-183 and then regulated the activation of FAK/PI3K/AKT/β-catenin pathway was explored. PDIA3P was discovered as up-regulated in BC tissues and cells. PDIA3P suppression markedly decreased cell viability, promoted apoptosis, and inhibited migration and invasion in MCF-7 cells. In addition, PDIA3P was found to be negatively interacting with miR-183, and PDIA3P regulated tumor growth and metastasis through negatively regulating miR-183. Moreover, ITGB1 was targeted by miR-183 and involved in tumor growth and metastasis. Lastly, PDIA3P suppression markedly inhibited the activation of FAK/PI3K/AKT/β-catenin pathway, which was significantly reversed after simultaneous inhibition of miR-183. Our results reveal that PDIA3P may forpromote BC development by sponging miR-183 to regulate ITGB1, thus inducing the activation of FAK/PI3K/AKT/β-catenin signals. PDIA3P may serve as a promising biomarker or target for the detection or treatment of BC.

lncRNA PLAC2 activated by H3K27 acetylation promotes cell proliferation and invasion via the activation of Wnt/β‑catenin pathway in oral squamous cell carcinoma

As a new group of important effector molecules involved in multiple cancer types, including breast cancer, lung cancer and oral squamous cell carcinoma, long noncoding RNAs (lncRNAs) have attracted considerable attention recently. However, the underlying cause that induces the dysregulated lncRNAs in cancer remains poorly understood. In the present study, the regulatory model of the lncRNA placenta‑specific protein 2 (PLAC2) upregulation in oral squamous cell carcinoma (OSCC) was investigated and its biological functions in OSCC malignant progression was identified. A reverse transcription‑quantitative polymerase chain reaction assay identified that PLAC2 is upregulated in OSCC cell lines and primary tissue samples. Furthermore, bioinformatic analysis followed by chromatin immunoprecipitation verified an enriched histone H3 on lysine 27 (H3K27) acetylation (H3K27ac) at the promoter region of the PLAC2 gene. Knockdown of cAMP‑response element binding protein‑binding protein (CBP) significantly reduced the enrichment level of H3K27ac, and thereby induced a decreased expression of PLAC2. Functionally, overexpression of PLAC2 promotes OSCC cell proliferation, migration and invasion, whereas knockdown of PLAC2 exerted an opposite effect. Furthermore, the Wnt/β‑catenin signaling pathway was activated by PLAC2 and mediated the PLAC2‑induced malignant progress of OSCC. In conclusion, the present results indicated that lncRNA PLAC2 is transcriptionally activated by H3K27ac modification at the promoter region in OSCC, and promotes cell growth and metastasis via activating Wnt/β‑catenin signaling pathway. Therefore, PLAC2 may serve as a promising biomarker for OSCC prognosis and therapy.

lnc TINCR induced by NOD1 mediates inflammatory response in 3T3-L1 adipocytes

OBJECTIVE

Investigating the expression of the lnc RNAs screened above between normal and insulin resistant 3T3-L1 adipocytes. Addressing the mechanism underlying the regulation of inflammation response by lnc TINCR.

METHODS

3T3-L1 preadipocytes were induced to differentiate into mature adipocytes. Oil red O staining was used to find the fat droplets in mature adipocytes. Mature adipocytes were randomized to normal control group and Tri-DAP (NOD1 ligand) group. After the establishment of insulin resistance model, we used deep RNA sequencing(RNA-Seq) to identify lncRNAs that are regulated during NODI activation in mouse adipocytes. Real-time PCR was used to analyze the expression of lnc TINCR, proinflammatory IL-6, TNF-α, Cxcl1 and RIPK2 in the presence or absence of Tri-DAP(10 μg/ml). We employed siRNA against lnc TINCR to confirm its effects in inflammatory response.

RESULTS

Deep RNA sequencing identified 81 lncRNAs and 167 coding genes that were significantly up-related while 78 lncRNAs and 82 coding genes that were significantly down-related greater than twofold during NOD1 activation in adipocytes. We discovered that lnc TINCR, termed lnc TINCR(Tri-DAP-inducible non-protein coding RNA) is greatly upregulated in Tri-DAP activated adipocytes. Moreover knockdown of lnc TINCR dampens the proinflammatory response (P < 0.05; in adipocytes).

CONCLUSIONS

lnc TINCR is a positive regulator of inflammation-induced insulin resistance presumably via activation of NOD1 signaling pathways.

LncRNA H19 interacted with miR-130a-3p and miR-17-5p to modify radio-resistance and chemo-sensitivity of cardiac carcinoma cells

The current investigation explored the synthetic contribution of lncRNA H19, miR-130a-3p, and miR-17-5p to radio-resistance and chemo-sensitivity of cardiac cancer cells. Totally 284 human cardiac cancer tissues were gathered, and they have been pathologically diagnosed. The cardiac cancer cells were isolated with utilization of the mechanic method. Moreover, cisplatin, adriamycin, mitomycin, and 5-fluorouracil were designated as the chemotherapies, and single-dose X-rays were managed as the radiotherapy for cardiac cancer cells. We also performed luciferase reporter gene assay to verify the targeted relationship between H19 and miR-130a-3p, as well as between H19 and miR-17-5p. Finally, mice models were established to examine the functions of H19, miR-130a-3p, and miR-17-5p on the development of cardiac cancer. The study results indicated that H19, miR-130a-3p, and miR-17-5p expressions within cardiac cancer tissues were significantly beyond those within adjacent nontumor tissues (P < 0.05), and H19 expression was positively correlated with both miR-130a-3p (r_s  = 0.43) and miR-17-5p (r_s  = 0.49) expressions. The half maximal inhibitory concentrations (IC50) of cisplatin, adriamycin, mitomycin, and 5-fluorouracil for cardiac cancer cells were, respectively, determined as 2.01 μg/mL, 8.35 μg/mL, 24.44 μg/mL, and 166.42 μg/mL. The overexpressed H19, miR-130a-3p, and miR-17-5p appeared to improve the survival rate and viability of cardiac cancer cells that were exposed to chemotherapies and X-rays (all P < 0.05). It was also drawn from luciferase reporter gene assay that H19 could directly target miR-130a-3p and miR-17-5p, thereby modifying the sensitivity of cardiac cancer cells to drugs and X-rays (P < 0.05). Finally, the mice models also produced larger tumor size and higher tumor weight, when H19, miR-130a-3p, or miR-17-5p expressions were up-regulated within them (P < 0.05). In conclusion, H19 could act on miR-130a-3p or miR-17-5p to alter the radio- and chemo-sensitivities of cardiac cancer cells, helping to improve the radio-/chemotherapies for cardiac cancer.

MiR-326/Sp1/KLF3: A novel regulatory axis in lung cancer progression

OBJECTIVES

To investigate the function and regulatory mechanism of Krüppel-like factor 3 (KLF3) in lung cancer.

MATERIALS AND METHODS

KLF3 expression was analysed by qRT-PCR and Western blot assays. The proliferation, migration, invasion, cycle and apoptosis were measured by CCK-8 and EdU, wound-healing and Transwell, and flow cytometry assays. The tumour growth was detected by nude mouse tumorigenesis assay. In addition, the interaction between KLF3 and Sp1 was accessed by luciferase reporter, EMSA and ChIP assay. JAK2, STAT3, PI3K and p-AKT levels were evaluated by Western blot and IHC assays.

RESULTS

The results indicated that KLF3 expression was elevated in lung cancer tissues. Knockdown of KLF3 inhibited lung cancer cell proliferation, migration and invasion, and induced cell cycle arrest and apoptosis. In addition, the downregulation of KLF3 suppressed tumour growth in vivo. KLF3 was transcriptionally activated by Sp1. miR-326 could bind to 3'UTR of Sp1 but not KLF3 and decreased the accumulation of Sp1, which further indirectly reduced KLF3 expression and inactivated JAK2/STAT3 and PI3K/AKT signaling pathways in vitro and in vivo.

CONCLUSIONS

Our data demonstrate that miR-326/Sp1/KLF3 regulatory axis is involved in the development of lung cancer, which hints the potential target for the further therapeutic strategy against lung cancer.

Upregulation of lncRNA NR_046683 Serves as a Prognostic Biomarker and Potential Drug Target for Multiple Myeloma

Aim: To investigate the prognostic value of lncRNA NR_046683 in multiple myeloma (MM).

Methods: High-throughput lncRNA array was combined with bioinformatics techniques to screen differentially expressed lncRNA in MM. qRT-PCR was adopted to determine the expression of target lncRNAs in MM patients and controls.

Results: It was found for the first time that lncRNA NR_046683 is closely related to the prognosis of MM. It was also detected in tumor cell lines KM3, U266, especially in drug-resistant cell lines KM3/BTZ and MM1R. The NR_046683 expression differed significantly in patients of different MM subtypes and staging. Moreover, the overexpression of NR-046683 is closely related to β₂-microglobulin. We also found that the overexpression of NR-046683 correlates to chromosomal aberrations, such as del(13q14), gain 1q21, and t(4;14).

Conclusion: lncRNA NR_046683 can serve as a novel biomarker for potential drug target and prognostic prediction in MM.

Hypoxia-sensitive LINC01436 is regulated by E2F6 and acts as an oncogene by targeting miR-30a-3p in non-small cell lung cancer

Dysregulation of long noncoding RNA (lncRNA) is known to be involved in numerous human diseases, including lung cancer. However, the precise biological functions of most lncRNA remain to be elucidated. Here, we identified a novel up‐regulated lncRNA, LINC01436 (RefSeq: NR_110419.1), in non‐small cell lung cancer (NSCLC). High expression of LINC01436 was significantly associated with poor overall survival. Notably, LINC01436 expression was transcriptionally repressed by E2F6 under normoxia, and the inhibitory effect was relieved in a hypoxic microenvironment. Gain‐ and loss‐of‐function studies revealed that LINC01436 acted as a proto‐oncogene by promoting lung cancer cell growth, migration and invasion in vitro. Xenograft tumor assays in nude mice confirmed that LINC01436 promoted tumor growth and metastasis in vivo. Mechanistically, LINC01436 exerted biological functions by acting as a microRNA (miR)‐30a‐3p sponge to regulate the expression of its target gene EPAS1. Our findings characterize LINC01436 as a new hypoxia‐sensitive lncRNA with oncogenic function in NSCLC, suggesting that LINC01436 may be a potential biomarker for prognosis and a potential target for treatment.

miR-15b-5p targeting amyloid precursor protein is involved in the anti-amyloid eflect of curcumin in swAPP695-HEK293 cells

Curcumin exerts a neuroprotective effect on Alzheimer's disease; however, it is not known whether microRNAs are involved in this protective effect. This study was conducted using swAPP695-HEK293 cells as an Alzheimer's disease cell model. swAPP695-HEK293 cells were treated with 0, 0.5, 1, 2, 5, and 10 μM curcumin for 24 hours. The changes in miR-15b-5p, miR-19a-3p, miR-195-5p, miR-101-3p, miR-216b-5p, miR-16-5p and miR-185-5p expression were assessed by real-time quantitative polymerase chain reaction. The mRNA and protein levels of amyloid precursor protein, amyloid-β40 and amyloid-β42 were evaluated by quantitative real-time polymerase chain reaction, western blot assays and enzyme-linked immunosorbent assays. swAPP695-HEK293 cells were transfected with miR-15b-5p mimic, or treated with 1 μM curcumin 24 hours before miR-15b-5p inhibitor transfection. The effects of curcumin on amyloid precursor protein, amyloid-β40 and amyloid-β42 levels were evaluated by western blot assays and enzyme-linked immunosorbent assay. Luciferase assays were used to analyze the interaction between miR-15b-5p and the 3'-untranslated region of amyloid precursor protein. The results show that amyloid precursor protein and amyloid-β expression were enhanced in swAPP695-HEK293 cells compared with HEK293 parental cells. Curcumin suppressed the expression of amyloid precursor protein and amyloid-β and up-regulated the expression of miR-15b-5p in swAPP695-HEK293 cells. In addition, we found a negative association of miR-15b-5p expression with amyloid precursor protein and amyloid-β levels in the curcumin-treated cells. Luciferase assays revealed that miR-15b-5p impaired the luciferase activity of the plasmid harboring the 3'-untranslated region of amyloid precursor protein. These findings indicate that curcumin down-regulates the expression of amyloid precursor protein and amyloid-β in swAPP695-HEK293 cells, which was partially mediated by miR-15b-5p via targeting of the 3'-untranslated region of amyloid precursor protein.

Long intergenic noncoding RNA-p21 inhibits apoptosis by decreasing PUMA expression in non-small cell lung cancer

OBJECTIVE

Long noncoding RNAs (lncRNAs) are important mediators in tumor progression. Long intergenic noncoding RNA-p21 (lincRNA-p21) participates in multiple biological processes. This study explored the role of lincRNA-p21 in human non-small cell lung cancer (NSCLC) progression and potential regulatory mechanisms.

METHODS

LincRNA-p21 expression in NSCLC tissues and cell lines (A549, H1299, H1650, and NCI-H2087) was determined by quantitative real-time PCR. LincRNA-p21 overexpressing and sh-lincRNA-p21 lentiviral were respectively transfected into H1299 and A549 cells. Flow cytometry was used to measure apoptosis. Microarray analysis and RNA pull-down assay were used to predict the target genes of lincRNA-p21. Finally, PUMA siRNA and overexpressing PUMA were transfected into NSCLC cells, and the extent of cell apoptosis was measured. The protein expression levels of the relative genes were confirmed by western blot analysis.

RESULTS

LincRNA-p21 was significantly upregulated in NSCLC tissues and cells. The upregulation of lincRNA-p21 considerably inhibited cell apoptosis while the downregulation of lincRNA-p21 showed the opposite effect. PUMA was a direct target gene of lincRNA-p21 and was negatively correlated with lincRNA-p21 in NSCLC specimens. The anti-apoptotic effect of lincRNA-p21 can be effectively attenuated by the upregulation of PUMA.

CONCLUSION

LincRNA-p21 is aberrantly upregulated in NSCLC and inhibits cell apoptosis by decreasing PUMA expression.

microRNA-181b suppresses the metastasis of lung cancer cells by targeting sex determining region Y-related high mobility group-box 6 (Sox6)

BACKGROUND

The aim of the study was to measure the expression of microRNA (miR)-181b in patients with lung cancer, investigate its biological function and elucidate the underlying mechanisms associated with the development of lung cancer.

METHODS

miR-181b expression in tissues was measured via RT-qPCR. After A549 cells were transfected with miR-181b mimic or si-Sox6, the proliferation, migration and cell cycle distribution of A549 were evaluated using cell counting kit-8 assay, transwell assay and flow cytometry. The levels of cell cycle-related proteins and Sox6 were analyzed by western blotting. Gene targets of miR-181b were predicted via bioinformatics analysis and verified using a dual-luciferase reporter gene assay.

RESULTS

Expression of miR-181b was significantly downregulated in lung cancer tissues (P < 0.05), and was inversely correlated with the degree of cell differentiation and clinical stages of lung cancer (both P < 0.05). Additionally, the expression of miR-181b was significantly lower in adenocarcinoma compared with squamous cell carcinoma in the lungs (P < 0.05). Overexpression of miR-181b significantly decreased the protein level of Sox6 and significantly suppressed the cell proliferation and metastasis (both P < 0.05); this effect was also observed in A549 cells transfected with si-Sox6. The luciferase activity of a Sox6 3'-untranslated region-based reporter construct was significantly lower when transfected with miR-181b (P < 0.05), which suggests that Sox6 is a direct target of miR-181b.

CONCLUSION

The results of the present study suggest that miR-181b may function as a tumor inhibitor in the development of lung cancer via targeting Sox6 to decrease the proliferation and metastasis of lung cancer cells.

Long noncoding RNA FOXD2-AS1 promotes glioma malignancy and tumorigenesis via targeting miR-185-5p/CCND2 axis

Glioma is the most aggressive malignant tumor in the adult central nervous system. Abnormal long noncoding RNA (lncRNA) FOXD2-AS1 expression was associated with tumor development. However, the possible role of FOXD2-AS1 in the progression of glioma is not known. In the present study, we used in vitro and in vivo assays to investigate the effect of abnormal expression of FOXD2-AS1 on glioma progression and to explore the mechanisms. FOXD2-AS1 was upregulated in glioma tissue, cells, and sphere subpopulation. Upregulation of FOXD2-AS1 was correlated with poor prognosis of glioma. Downregulation of FOXD2-AS1 decreased cell proliferation, migration, invasion, stemness, and epithelial-mesenchymal transition (EMT) in glioma cells and inhibited tumor growth in transplanted tumor. We also revealed that FOXD2-AS1 was mainly located in cytoplasm and microRNA (miR)-185-5p both targeted FOXD2-AS1 and CCND2 messenger RNA (mRNA) 3'-untranslated region (3'-UTR). miR-185-5p was downregulated in glioma tissue, cells, and sphere subpopulation. Downregulation of miR-185-5p was closely correlated with poor prognosis of glioma patients. In addition, miR-185-5p mimics decreased cell proliferation, migration, invasion, stemness, and EMT in glioma cells. CCND2 was upregulated in glioma tissue, cells, and sphere subpopulation. Upregulation of CCND2 was closely correlated with poor prognosis of glioma patients. CCND2 knockdown decreased cell proliferation, migration, invasion, and EMT in glioma cells. In glioma tissues, CCND2 expression was negatively associated with miR-185-5p, but positively correlated with FOXD2-AS1. FOXD2-AS1 knockdown and miR-185-5p mimics decreased CCND2 expression. Inhibition of miR-185-5p suppressed FOXD2-AS1 knockdown-induced decrease of CCND2 expression. Overexpression of CCND2 suppressed FOXD2-AS1 knockdown-induced inhibition of glioma malignancy. Taken together, our findings highlight the FOXD2-AS1/miR-185-5p/CCND2 axis in the glioma development.

Circ_0078767 suppresses non-small-cell lung cancer by protecting RASSF1A expression via sponging miR-330-3p

Objectives

This study was designed to investigate the role of circ_0078767/miR‐330‐3p/RASSF1A in non‐small‐cell lung cancer (NSCLC). Bioinformatic analysis was performed to screen for the differentially expressed genes in NSCLC tissues from adjacent lung tissues.

Materials and Methods

qRT‐PCR was used to detect the RNA expression of genes in cells and tissues, and Western blot was conducted to determine the protein levels of RASSF1A in tissues and cells. A miRanda algorithm was used to predict the targeted relationship among RNAs. A dual‐luciferase reporter gene assay was conducted to verify the targeted relationship. Flow cytometry was performed to investigate the effects of circ_0078767/miR‐330‐3p/RASSF1A on cell cycle progression and apoptosis. A CCK‐8 assay was conducted to explore the effects of circ_0078767/miR‐330‐3p/RASSF1A on cell proliferation. A transwell invasion assay was completed to study the effects of circ_0078767/miR‐330‐3p/RASSF1A on cell invasion. Lastly, an in vivo assay was conducted to investigate the effects of circ_0078767/miR‐330‐3p/RASSF1A on tumour development.

Results

Circ_0078767 and RASSF1A were downregulated, while miR‐330‐3p was upregulated in NSCLC tissues than that in adjacent tissues. miR‐330‐3p had a binding relationship with circ_0078767 and RASSF1A. The overexpression of circ_0078767 and RASSF1A or the underexpression of miR‐330‐3p significantly suppressed NSCLC cell viability, cell cycle progression and invasion while also significantly promoting cell apoptosis. Additionally, these modulations significantly suppressed in vivo tumour growth.

Conclusions

Circ_0078767 could suppress NSCLC progression by inhibiting miR‐330‐3p, which thereby increased RASSF1 levels.

FGFR1 is an independent prognostic factor and can be regulated by miR-497 in gastric cancer progression

Fibroblast growth factor receptor 1 (FGFR1) has been reported in gastric cancer to be a prognostic factor. However, miR-497-targeted FGFR1 has not been explored in the carcinogenesis of gastric cancer. The present study intended to revalidate the prognostic significance of FGFR1 in patients with gastric cancer, and the mechanism of miR-497-regulated FGFR1 was investigated in gastric cancer cell proliferation and apoptosis. The messenger RNA (mRNA) and protein levels were assayed by RT-qPCR and western blotting, respectively. The targeted genes were predicted by a bioinformatics algorithm and confirmed by a dual luciferase reporter assay. Cell proliferation was analyzed by CCK-8 assay. Annexin V-FITC/PI staining was used to evaluate the apoptosis in AGS and SGC-7901 cells. FGFR1 was frequently up-regulated in gastric cancer tissues and associated with poor overall survival in patients with gastric cancer. Interestingly, FGFR1 loss-of-function resulted in a significant growth inhibition and apoptosis in AGS and SGC-7901 cells. In addition, we found that miR-497 was inhibited in gastric cancer tissues and cell lines, while overexpression of miR-497 could suppress proliferation and induce apoptosis in AGS and SGC-7901 cells. Importantly, bioinformatics analysis and experimental data suggested that FGFR1 was a direct target of miR-497, which could inhibit FGFR1 expression when transfected with miR-497 mimics. Furthermore, we found that overexpression of FGFR1 reversed the growth inhibition and apoptosis of miR-497 mimics in AGS and SGC-7901 cells. These findings suggested that overexpression of miR-497 inhibited proliferation and induced apoptosis in gastric cancer through the suppression of FGFR1.

LINC00210 as a miR-328-5p sponge promotes nasopharyngeal carcinoma tumorigenesis by activating NOTCH3 pathway

As a kind of essential regulators, long noncoding RNAs (lncRNAs) have attracted a lot of attention in recent years. Nevertheless, the function of lncRNA in nasopharyngeal carcinoma (NPC) remains poorly understood. In the present study, we explained the role and mechanism of LINC00210 in NPC progression. We found that LINC00210 expression was up-regulated in NPC samples. Besides, its overexpression was positively correlated with NPC metastasis while predicting poor prognosis. Based on functional experiments, we revealed that LINC00210 contributed to NPC cell proliferation and invasion in vitro, and promotes tumor growth in vivo. Mechanistically, we identified that LINC00210 was located in the cytoplasm of NPC cells and served as the miR-328-5p sponge. Furthermore, we showed that miR-328-5p targets the 3′ untranslated region (3′-UTR) of NOTCH3. Through inhibiting miR-328-5p activity, LINC00210 promoted NOTCH3 expression in NPC, leading to activation of NOTCH3 signaling pathway. In conclusion, our study indicates LINC00210 promotes NPC progression through modulating proliferation and invasion.

Long non-coding RNA SNHG20 promotes the tumorigenesis of oral squamous cell carcinoma via targeting miR-197/LIN28 axis

Long non‐coding RNA (lncRNA) has been verified to participate in the tumour regulation, including oral squamous cell carcinoma (OSCC). Nevertheless, the role of lncRNA SNHG20 on OSCC still remains elusive. Here, we investigate the physiopathologic functions of lncRNA SNHG20 in OSCC tumorigenesis and explore its potential mechanism. LncRNA SNHG20 was up‐regulated in OSCC tissue compared with adjacent non‐tumour tissue. Meanwhile, SNHG20 was overexpressed in cancer stem‐like cells. In vitro and in vivo, loss‐of‐function experiments showed that lncRNA SNHG20 knockdown inhibited proliferative ability, mammosphere‐forming ability, ALDH1 expression, stem factors (LIN28, Nanog, Oct4, SOX2) and tumour growth. Bioinformatics and luciferase reporter assay revealed that miR‐197 targeted the 3′‐untranslated regions of SNHG20 and LIN28 by complementary binding. Validation experiments confirmed the associated functions of SNHG20/miR‐197/LIN28 axis on OSCC proliferation and stemness. In summary, our results reveal the important function of SNHG20/miR‐197/LIN28 axis in the oncogenesis and stemness of OSCC, suggesting the vital role of SNHG20 in OSCC tumorigenesis.

SF3B4 is regulated by microRNA-133b and promotes cell proliferation and metastasis in hepatocellular carcinoma

BACKGROUND

Splicing factor 3b subunit 4 (SF3B4) is a splicing factor and potential oncogene in hepatocellular carcinoma (HCC); however, its regulatory mechanism is yet unclear. We aimed to determine the role of SF3B4 in HCC and the underlying mechanism.

METHODS

To investigate the association between alternative splicing events and miRNAs, putative miRNAs were screened using TargetScan. Expression levels of and prognostic information for SF3B4 and miRNAs were determined based on public genomic data and clinical samples. Then, we examined the possible roles of SF3B4 and miRNA-133b in HCC cells and a xenograft mouse model. Pearson correlation analysis and in vitro experiments verified SF3B4 as a miRNA-133b target. Protein levels of key targets from the SF3B4 signaling pathway were estimated using western blotting.

FINDINGS

The expression of SF3B4 was upregulated in HCC tissues and cell lines whereas, the expression of miRNA-133b was downregulated. MiRNA-133b negatively regulated the expression of SF3B4. Effects of SF3B4 overexpression were partially abolished by miRNA-133b mimics, confirming that SF3B4 is a target of miRNA-133b. Moreover, molecules associated with SF3B4, including KLF4, KIP1, and SNAI2, were also modulated by miRNA-133b.

INTERPRETATION

SF3B4 plays a crucial role in HCC and is negatively regulated by miRNA-133b. The miRNA-133b/ SF3B4 axis may serve as a new therapeutic target for HCC treatment. FUND: China National Funds for Distinguished Young Scientists (No.81425019), the State Key Program of National Natural Science Foundation of China (No.81730076), Shanghai Science and Technology Committee Program (No.18XD1405300) and Specially-Appointed Professor Fund of Shanghai (GZ2015009). China National Funds for National Natural Science Fund (No.81672899).

Long non-coding RNA THOR promotes liver cancer stem cells expansion via β-catenin pathway

Hepatocellular carcinoma (HCC) is a highly aggressive liver tumor containing cancer stem cells (CSCs), which participate in tumor invasion, therapeutic resistance, and tumor relapse leading to poor outcome and limited therapeutic options. Recently, a novel lncRNA, THOR (testis-associated highly conserved oncogenic long non-coding RNA), was characterized in human cancers and shown to exhibit an oncogenic role. However, the role of THOR in liver cancer stem cells (CSCs) remains obscure. Herein, we observed high expression of THOR in chemoresistant hepatocellular carcinomas (HCCs). A remarkable increase of THOR expression in OV6 or EpCAM-positive liver CSCs as well as in CSC-enriched hepatoma spheres. Interference THOR suppressed liver CSC expansion by inhibiting the dedifferentiation of hepatoma cells and decreasing the self-renewal ability of liver CSCs. Mechanistically, we found β-catenin as the downstream of THOR in HCC cells. The special β-catenin inhibitor FH535 abolished the discrepancy in liver CSC proportion and the self-renewal capacity between THOR knockdown HCC cells and control cells, which further confirmed that β-catenin was required in THOR promoted liver CSCs expansion. Moreover, interference THOR hepatoma cells were more sensitive to sorafenib treatment, indicates that HCC patients with low THOR expression may benefit from sorafenib treatment. Collectively, THOR was upregulated in liver CSCs and could promote HCC cells dedifferentiation and liver CSCs expansion by targeting β-catenin signaling.

MicroRNA-202-5p functions as a tumor suppressor in colorectal carcinoma by directly targeting SMARCC1

Recently, microRNAs (miRNAs) have been emerged as critical regulators for human diseases and as prognostic markers in several tumors, including colorectal carcinoma (CRC). Herein, we identified a tumor-suppressive miRNA, miR-202-5p, which may suppress CRC tumorigenesis. SWI/SNF related, matrix associated, actin dependent regulator of chromatin subfamily c member 1 (SMARCC1) is a susceptibility gene in CRC. However, the role of SMARCC1 in CRC tumorigenesis has not been elucidated. In our present study, we demonstrated that miR-202-5p was a tumor-suppressive miRNA in CRC progression. We found that expression of miR-202-5p was obviously decreased in CRC tissues. Down-regulation of miR-202-5p was associated with postoperative survival. Overexpression of miR-202-5p inhibited the growth and metastasis of CRC cells. The SMARCC1 was a direct target of miR-202-5p and promoted the growth and metastasis of CRC cells. Further study showed that SMARCC1 could reverse the inhibitory effect of miR-202-5p on growth and metastasis of CRC cells. In conclusion, our data highlight the key role of miR-202-5p in the progression of CRC. Thus, miR-202-5p may be a potential prognostic marker and of treatment relevance for CRC progression intervention.

A novel long non-coding RNA, AC012456.4, as a valuable and independent prognostic biomarker of survival in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a major malignant cancer of the head and neck. Long non-coding RNAs (lncRNAs) have emerged as critical regulators during the development and progression of cancers. This study aimed to identify a lncRNA-related signature with prognostic value for evaluating survival outcomes and to explore the underlying molecular mechanisms of OSCC. Associations between overall survival (OS), disease-free survival (DFS) and candidate lncRNAs were evaluated by Kaplan–Meier survival analysis and univariate and multivariate Cox proportional hazards regression analyses. The robustness of the prognostic significance was shown via the Gene Expression Omnibus (GEO) database. A total of 2,493 lncRNAs were differentially expressed between OSCC and control samples (fold change >2, p < 0.05). We used Kaplan–Meier survival analysis to identify 21 lncRNAs for which the expression levels were associated with OS and DFS of OSCC patients (p < 0.05) and found that down-expression of lncRNA AC012456.4 especially contributed to poor DFS (p = 0.00828) and OS (p = 0.00987). Furthermore, decreased expression of AC012456.4 was identified as an independent prognostic risk factor through multivariate Cox proportional hazards regression analyses (DFS: p = 0.004, hazard ratio (HR) = 0.600, 95% confidence interval(CI) [0.423–0.851]; OS: p = 0.002, HR = 0.672, 95% CI [0.523–0.863). Gene Set Enrichment Analysis (GSEA) indicated that lncRNA AC012456.4 were significantly enriched in critical biological functions and pathways and was correlated with tumorigenesis, such as regulation of cell activation, and the JAK-STAT and MAPK signal pathway. Overall, these findings were the first to evidence that AC012456.4 may be an important novel molecular target with great clinical value as a diagnostic, therapeutic and prognostic biomarker for OSCC patients.

LncRNA GACAT3 acts as a competing endogenous RNA of HMGA1 and alleviates cucurbitacin B-induced apoptosis of gastric cancer cells

Long non-coding RNAs (lncRNAs) have been demonstrated to perform important roles in cancer development. Previously, we have shown that lncRNA gastric cancer-associated transcript 3 (GACAT3) is overexpressed in gastric cancer and acts as a downstream target of interleukin 6/signal transducer and activator of transcription 3 (IL-6/STAT3) signaling. However, the role of GACAT3 in regulating gastric cancer cell growth remains unclear. In this study, we demonstrate that GACAT3 acts as a competing endogenous RNA of high mobility group A1 (HMGA1), a typical oncogene that is overexpressed in most types of cancer, based on a search for common miRNA-binding sites and on experiments involving in vitro cell transfection with synthesized miRNA mimics. Furthermore, knockdown of GACAT3 by its specific siRNA resulted in significantly decreased cell proliferation in gastric cancer cells, similar to the effect of an HMGA1 knockdown. Moreover, GACAT3 overexpression alleviated the apoptosis induced by cucurbitacin B, which is a widely used anticancer drug. Mechanistically, GACAT3 amplified STAT3 expression and decreased the level of the apoptosis gene bcl-2-associated X protein (BAX). Thus, our study provides fundamental information regarding GACAT3, which could be a valuable target for gastric cancer therapy.

Long non-coding RNA THOR promotes cell proliferation and metastasis in hepatocellular carcinoma

Long non-coding RNAs (lncRNAs) have been demonstrated to be involved in the development and progression of multiple cancers by previous studies. Recently, a novel lncRNA, THOR (testis-associated highly conserved oncogenic long non-coding RNA), was characterized in human cancers and shown to exhibit an oncogenic role. However, the role of THOR in hepatocellular carcinoma (HCC) is still unclear. In this study, we found that THOR was relatively highly expressed in human HCC tissues and cell lines. Notably, high THOR expression was associated with worse prognosis. THOR depletion resulted in significant inhibition of the growth and metastasis of HCC cells. Mechanistically, THOR drives HCC cell progression via the PTEN/AKT pathway. Moreover, the specific PI3-K inhibitor LY294002 abolished the discrepancy in the growth and metastatic capacity between THOR-silenced HCC cells and control cells, which further confirmed that AKT was required in THOR-driven HCC cell growth and metastasis. Taken together, our results suggest that THOR could promote HCC cell growth and metastasis by amplifying PTEN/AKT signaling and may be a new therapeutic target and predictive factor for HCC.

lncRNA ZEB1-AS1 Was Suppressed by p53 for Renal Fibrosis in Diabetic Nephropathy

The role of p53 in renal fibrosis is still controversial, and its underlying mechanisms remain not clear. Here, we showed that the pharmacological inhibition and genetic deletion of p53 in proximal tubular cells can attenuate renal dysfunction, tubular epithelial disruption, and interstitial fibrosis in db/db and STZ-induced diabetic nephrology (DN) mice. In human renal proximal tubule (human kidney 2 [HK-2]) cells, inhibition of p53 by PIF reduced the high glucose (HG)-induced extracellular matrix (ECM) accumulation and reversed the inhibitory effect of HG on mRNA expression levels of lncRNA zinc finger E-box binding homeobox1-antisense RNA 1 (ZEB1-AS1) and ZEB1. Interestingly, our results demonstrated that both lncRNA ZEB1-AS1 and ZEB1 exhibited an anti-fibrotic role, while ZEB1 is positively regulated by lncRNA ZEB1-AS1 during HG treatment. Mechanistically, lnc ZEB1-AS1 bound directly to H3K4 methyltransferase myeloid and lymphoid or mixed-lineage leukemia 1 (MLL1) and promoted H3K4me3 histone modification on ZEB1 promoter, which was reduced by HG treatment. ChIP analysis indicated the binding of p53 to the promoter region of lnc ZEB1-AS1. Furthermore, the findings were verified by the kidney biopsy samples from patients with DN. Taken all together, our results suggest that p53 may be a therapeutic target for renal fibrosis in DN.