LncRNA TUSC7 suppresses pancreatic carcinoma progression by modulating miR-371a-5p expression

Harnessing the ubiquitin proteasome system as a key player in stem cell biology

Intracellular proteins take part in almost every body function; thus, protein homeostasis is of utmost importance. The ubiquitin proteasome system (UPS) has a fundamental role in protein homeostasis. Its main role is to selectively eradicate impaired or misfolded proteins, thus halting any damage that could arise from the accumulation of these malfunctioning proteins. Proteasomes have a critical role in controlling protein homeostasis in all cell types, including stem cells. We will discuss the role of UPS enzymes as well as the 26S proteasome complex in stem cell biology from several angles. First, we shall overview common trends of proteasomal activity and gene expression of different proteasomal subunits and UPS enzymes upon passaging and differentiation of stem cells toward various cell lineages. Second, we shall explore the effect of modulating proteasomal activity in stem cells and navigate through the interrelation between proteasomes' activity and various proteasome-related transcription factors. Third, we will shed light on curated microRNAs and long non-coding RNAs using various bioinformatics tools that might have a possible role in regulating UPS in stem cells and possibly, upon manipulation, can enhance the differentiation process into different lineages and/or delay senescence upon cell passaging. This will help to decipher the role played by individual UPS enzymes and subunits as well as various interrelated molecular mediators in stem cells' maintenance and/or differentiation and open new avenues in stem cell research. This can ultimately provide a leap toward developing novel therapeutic interventions related to proteasome dysregulation.

An Overview for Clinicians on Intraductal Papillary Mucinous Neoplasms (IPMNs) of the Pancreas

Currently, there is no reliable method of discerning between low-risk and high-risk intraductal papillary mucinous neoplasms (IPMNs). Operative resection is utilized in an effort to resect those lesions with high-grade dysplasia (HGD) prior to the development of invasive disease. The current guidelines recommend resection for IPMN that involve the main pancreatic duct. Resecting lesions with HGD before their progression to invasive disease and the avoidance of resection in those patients with low-grade dysplasia is the optimal clinical scenario. Therefore, the importance of developing preoperative models able to discern HGD in IPMN patients cannot be overstated. Low-risk patients should be managed with nonsurgical treatment options (typically MRI surveillance), while high-risk patients would undergo resection, hopefully prior to the formation of invasive disease. Current research is evolving in multiple directions. First, there is an ongoing effort to identify reliable markers for predicting malignant transformation of IPMN, mainly focusing on genomic and transcriptomic data from blood, tissue, and cystic fluid. Also, multimodal models of combining biomarkers with clinical and radiographic data seem promising for providing robust and accurate answers of risk levels for IPMN patients.

The long noncoding RNA MIR4435-2HG enhances the migration, promotion, and glycolysis of nonsmall cell lung cancer cells by targeting the miR-371a-5p/SOX2/PI3K/Akt axis

Background

Nonsmall cell lung cancer is a leading cause of cancer-related death worldwide. The long noncoding RNA MIR4435-2HG has been shown to play a carcinogenic role in various cancers. The purpose of this study was to explore the role and regulatory mechanism of MIR4435-2HG in non-small cell lung cancer.

Methods

Quantitative real-time polymerase chain reaction was used to detect MIR4435-2HG and SRY-box transcription factor 2 in nonsmall cell lung cancer cells. Gain- or loss-of-function assays of MIR4435-2HG and SRY-box transcription factor 2 were subsequently conducted. Cell proliferation, apoptosis, migration, glycolysis, and invasion were tested. A nude mouse tumor model was constructed to determine the role of MIR4435-2HG and SRY-box transcription factor 2 in the growth of tumor cells in vivo. Furthermore, the interactions between MIR4435-2HG, miR-371a-5p and SRY-box transcription factor 2 were analyzed via a dual-luciferase reporter gene assay.

Results

Quantitative real-time polymerase chain reaction revealed that MIR4435-2HG and SRY-box transcription factor 2 were upregulated in nonsmall cell lung cancer cells. Forced MIR4435-2HG overexpression led to increased cell proliferation, migration, invasion, and glycolysis and repressed cell apoptosis. Overexpressing MIR4435-2HG promoted SRY-box transcription factor 2 expression and PI3K/Akt/mTOR pathway activation. Downregulating MIR4435-2HG had antitumor effects both in vitro and in vivo. SRY-box transcription factor 2 overexpression mostly reversed the suppressive effects of MIR4435-2HG downregulation. Mechanistic studies revealed that MIR4435-2HG, a competitive endogenous RNA, directly targeted and inhibited miR-371a-5p. Rescue assays revealed that miR-371a-5p overexpression or SRY-box transcription factor 2 downregulation significantly inhibited MIR4435-2HG-mediated oncogenic effects.

Conclusion

MIR4435-2HG promotes nonsmall cell lung cancer cell malignant behaviors and glycolysis by regulating the miR-371a-5p/SOX2 axis.

Endoscopic Ultrasound-Guided Needle-Based Confocal Endomicroscopy as a Diagnostic Imaging Biomarker for Intraductal Papillary Mucinous Neoplasms

Pancreatic cancer is on track to become the second leading cause of cancer-related deaths by 2030, yet there is a lack of accurate diagnostic tests for early detection. Intraductal papillary mucinous neoplasms (IPMNs) are precursors to pancreatic cancer and are increasingly being detected. Despite the development and refinement of multiple guidelines, diagnosing high-grade dysplasia or cancer in IPMNs using clinical, radiologic, endosonographic, and cyst fluid features still falls short in terms of accuracy, leading to both under- and overtreatment. EUS-guided needle-based confocal laser endomicroscopy (nCLE) is a novel technology that allows real-time optical biopsies of pancreatic cystic lesions. Emerging data has demonstrated that EUS-nCLE can diagnose and risk stratify IPMNs more accurately than conventional diagnostic tools. Implementing EUS-nCLE in clinical practice can potentially improve early diagnosis of pancreatic cancer, reduce unnecessary surgeries of IPMNs with low-grade dysplasia, and advance the field of digital pathomics. In this review, we summarize the current evidence that supports using EUS-nCLE as a diagnostic imaging biomarker for diagnosing IPMNs and for risk stratifying their degree of neoplasia. Moreover, we will present emerging data on the role of adding artificial intelligence (AI) algorithms to nCLE and integrating novel fluid biomarkers into nCLE.

Testicular germ cell tumour cells release microRNA-containing extracellular vesicles that induce phenotypic and genotypic changes in cells of the tumour microenvironment

Malignant germ-cell-tumours (GCTs) are characterised by microRNA (miRNA/miR-) dysregulation, with universal over-expression of miR-371~373 and miR-302/367 clusters regardless of patient age, tumour site, or subtype (seminoma/yolk-sac-tumour/embryonal carcinoma). These miRNAs are released into the bloodstream, presumed within extracellular-vesicles (EVs) and represent promising biomarkers. Here, we comprehensively examined the role of EVs, and their miRNA cargo, on (fibroblast/endothelial/macrophage) cells representative of the testicular GCT (TGCT) tumour microenvironment (TME). Small RNA next-generation-sequencing was performed on 34 samples, comprising representative malignant GCT cell lines/EVs and controls (testis fibroblast [Hs1.Tes] cell-line/EVs and testis/ovary samples). TME cells received TGCT co-culture, TGCT-derived EVs, and a miRNA overexpression system (miR-371a-OE) to assess functional relevance. TGCT cells secreted EVs into culture media. MiR-371~373 and miR-302/367 cluster miRNAs were overexpressed in all TGCT cells/subtypes compared with control cells and were highly abundant in TGCT-derived EVs, with miR-371a-3p/miR-371a-5p the most abundant. TGCT co-culture resulted in increased levels of miRNAs from the miR-371~373 and miR-302/367 clusters in TME (fibroblast) cells. Next, fluorescent labelling demonstrated TGCT-derived EVs were internalised by all TME (fibroblast/endothelial/macrophage) cells. TME (fibroblast/endothelial) cell treatment with EVs derived from different TGCT subtypes resulted in increased miR-371~373 and miR-302/367 miRNA levels, and other generic (eg, miR-205-5p/miR-148-3p) and subtype-specific (seminoma, eg, miR-203a-3p; yolk-sac-tumour, eg, miR-375-3p) miRNAs. MiR-371a-OE in TME cells resulted in increased collagen contraction (fibroblasts) and angiogenesis (endothelial cells), via direct mRNA downregulation and alteration of relevant pathways. TGCT cells communicate with nontumour stromal TME cells through release of EVs enriched in oncogenic miRNAs, potentially contributing to tumour progression.

lncRNA TUSC7 regulates oxidative stress level by targeting miR-23b in colorectal cancer and thus inhibits cell proliferation, migration and invasion

OBJECTIVE

Currently, multiple studies have shown that long non-coding ribonucleic acid TUSC7 exerts an anti-tumor effect in a variety of cancers. However, the function and underlying regulatory mechanism of lncRNA TUSC7 in CRC remain unclear.

METHODS

The relative fluorescence intensity of MMP9 in the cancer and in peritoneal tissues was measured by immunofluorescence. Peritoneal macrophages in BALB/c mice were sorted out using flow cytometry. The abdominal circumference of mice was measured. Moreover, the correlation between TUSC7 and miR-23b was detected by diluciferase experiment and the expressions of TUSC7 and miR-23b were analyzed using real-time fluorescence quantitative PCR. Last, the effect of TUSC7 on peritoneal macrophages was detected.

RESULTS

The relative fluorescence intensity of MMP9 in cancer was significantly stronger than that it in the surrounding tissues. Measurements of abdominal circumference in mice showed that TUSC7 inhibited the metastasis of CRC. The results of dual luciferase assay and RT-qPCR experiment showed that TUSC7 could target and inhibit miR-23b. The expressions of P22, P47, gp91, p-STAT6, p-STAT3, IL-4 and IL-10 were remarkably increased in TUSC7 OE group compared with those in NC group, while the expressions of p-SHP2, MMP2 and MMP9 were evidently reduced in contrast with those in NC group. The viability, proliferation, migration and invasion of CRC cells could be inhibited by TUSC7 OE, which was reversed by TUSC7 KD.

CONCLUSION

LncRNA TUSC7 can regulate the oxidative stress level and promote the M2 polarization of macrophages through targeting miR-23b of peritoneal macrophage in CRC, thus inhibiting cell proliferation, migration and invasion.

Molecular Analysis of Pancreatic Cyst Fluid for the Management of Intraductal Papillary Mucinous Neoplasms

Pancreatic cancer is one of the most lethal human cancers. Early detection and diagnosis of precursor lesions for pancreatic malignancy is essential to improve the morbidity and mortality associated with this diagnosis. Of the cystic precursor lesions, branch duct intraductal papillary mucinous neoplasm (IPMN) is the most frequently identified lesion and has a wide range of malignant potential. Currently, Carcinogenic embryonic antigen (CEA) levels in the cyst fluid and cytology are the two most often utilized tools to diagnose these lesions; however, their diagnostic and risk stratification capabilities are somewhat limited. Within the last decade, the use of endoscopic ultrasound-guided fine-needle aspiration has opened the door for molecular analysis of cystic fluid as an option to enhance both the diagnosis and risk stratification of these lesions. The first step is to differentiate branch duct IPMNs from other lesions. KRAS and GNAS alterations have been shown to be accurate markers for this purpose. Following cyst type identification, mutational analysis, telomere fusion, microRNAs, long non-coding RNA, and DNA methylation have been identified as potential targets for stratifying malignant potential using the cystic fluid. In this review, we will examine the various targets of cyst fluid molecular analysis and their utility in the diagnosis and risk stratification of branch duct IPMNs.

A Proposed TUSC7/miR-211/Nurr1 ceRNET Might Potentially be Disturbed by a cer-SNP rs2615499 in Breast Cancer

Evidence and in silico analyses showed that TUSC7, miR-211, and Nurr1 may be involved in BC pathogenesis by ceRNET signaling axis. This study aimed to investigate the potential role of TUSC7/miR-211/Nurr1 ceRNET and rs2615499 variant as a novel cer-SNP in BC subjects. The expression assays were conducted by qPCR on tumor tissues (n = 50), tumor-adjacent normal tissues (TANTs) (n = 50), and clinically healthy control tissues (n = 50). The expression of TUSC7 and Nurr1 significantly decreased, but the level of miR-211 significantly increased in tumor tissues compared to TANTs and healthy normal tissues. Altered expression of TUSC7 and miR-211 was associated with poor prognosis of patients. The Nurr1 exhibited a double-edged sword-like activity in BC. In addition, TUSC7, Nurr1, and miR-211 expressions were significantly related to a novel BC-associated rs2615499 (A > C) located in the miR-211 binding site on Nurr1 3'-UTR. In the second part of the study, a case-control study was performed on BC patients (n = 100) and matched healthy controls (n = 100). The genomic DNA was isolated and genotyping was performed using Tetra-Primer ARMS PCR. The CC and AC genotypes were associated with higher expression levels of Nurr1 and worse outcomes of the disease. Our findings revealed that TUSC7 functions as a tumor suppressor in BC potentially via miR-211/Nurr1, which might be disturbed by the cer-SNP rs2615499. However, functional studies are needed to validate these results.

Exosome-mediated lncRNA SNHG11 regulates angiogenesis in pancreatic carcinoma through miR-324-3p/VEGFA axis

Pancreatic carcinoma (PC) is one of the most common and deadly human malignancies worldwide. LncRNAs play significant roles in the occurrence and development of various cancers. LncRNA SNHG11 (SNHG11) has been found to display high expression in serum of PC patients, which implies that dysregulated SNHG11 may be related to the development of PC. However, there is still a knowledge gap concerning the specific function and molecular mechanism of SNHG11 in PC. After conducting experiments with constructed models in vitro or in vivo, we found that exosomal SNHG11 promoted cell proliferation, migration, and angiogenesis but impeded cell apoptosis in PC in vitro, and additionally, it facilitated tumor growth in vivo. Exosome-mediated SNHG11 regulated the expression of VEGFA through sponging miR-324-3p. Rescue assays validated that the inhibitory effect of SNHG11 depletion on cell proliferation, migration, and angiogenesis could be reversed by miR-324-3p downregulation or VEGFA upregulation, and the promoting effect of SNHG11 silence on cell apoptosis could be rescued by transfection of miR-324-3p inhibitor or pcDNA3.1-VEGFA. To conclude, exosomal-mediated SNHG11 could regulate PC progression via miR-324-3p/VEGFA axis. Our findings may provide a novel insight for understanding PC, which might contribute to the development of potential PC biomarker.

Differences in genetics and microenvironment of lung adenocarcinoma patients with or without TP53 mutation

Background

Differences in genetics and microenvironment of LUAD patients with or without TP53 mutation were analyzed to illustrate the role of TP53 mutation within the carcinogenesis of LUAD, which will provide new concepts for the treatment of LUAD.

Methods

In this study, we used genetics and clinical info from the TCGA database, including somatic mutations data, RNA-seq, miRNA-seq, and clinical data. More than one bioinformatics tools were used to analyze the unique genomic pattern of TP53-related LUAD.

Results

According to TP53 gene mutation status, we divided the LUAD patients into two groups, including 265 in the mutant group (MU) and 295 in the wild-type group (WT). 787 significant somatic mutations were detected between the groups, including mutations in titin (TTN), type 2 ryanodine receptor (RYR2) and CUB and Sushi multiple domains 3(CSMD3), which were up-regulated in the MU. However, no significant survival difference was observed. At the RNA level, we obtained 923 significantly differentially expressed genes; in the MU, α-defensin 5(DEFA5), pregnancy-specific glycoprotein 5(PSG5) and neuropeptide Y(NPY) were the most up-regulated genes, glucose-6-phosphatase (G6PC), alpha-fetoprotein (AFP) and carry gametocidal (GC) were the most down-regulated genes. GSVA analysis revealed 30 significant pathways. Compared with the WT, the expression of 12 pathways in the mutant group was up-regulated, most of which pointed to cell division. There were significant differences in tumor immune infiltrating cells, such as Macrophages M1, T cells CD4 memory activated, Mast cells resting, and Dendritic cells resting. In terms of immune genes, a total of 35 immune-related genes were screened, of which VGF (VGF nerve growth factor inducible) and PGC (peroxisome proliferator-activated receptor gamma coactivator) were the most significant up-regulated and down-regulated genes, respectively. Research on the expression pattern of immunomodulators found that 9 immune checkpoint molecules and 6 immune costimulatory molecules were considerably wholly different between the two groups.

Conclusions

Taking the mutant group as a reference, LUAD patients in the mutant group had significant differences in somatic mutations, mRNA-seq, miRNA-seq, immune infiltration, and immunomodulators, indicating that TP53 mutation plays a crucial role in the occurrence and development of LUAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01671-8.

Polymorphism of TUSC7 associated with gastric cancer susceptibility and binding with miR-133a-3p: a population-based case-control study

BACKGROUND

Previous studies have demonstrated that gene polymorphism is associated with cancer susceptibility. Most of these genes are involved in neoplastic processes. Previous studies demonstrated that tumor-suppressor candidate 7 (TUSC7) was a tumor-suppressor gene in various tumors. This study aims to explore the association between lncRNA TUSC7 polymorphism and gastric cancer susceptibility and the potential function.

METHODS

The tagging SNPs of TUSC7 were genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in a Chinese Han population-based case-control study. The relative expression level of TUSC7 in plasma was conducted by quantitative real-time PCR (qRT-PCR). The gene-environment interaction was analyzed by multifactor dimensionality reduction (MDR). The dual luciferase reporter assay was used to examine whether SNP rs12494960 of TUSC7 allele variation affected the binding of lncRNA-TUSC7 and miRNAs miR-133a-3p.

RESULTS

Three tagging SNPs (rs12494960, rs1518338, rs2867837) of TUSC7 were selected to validate in population. The unconditional multiple logistic regression showed that individuals with genotype AA (OR: 1.79, 95% CI: 1.16, 2.70) of rs12494960 and GG (OR: 2.24, 95% CI: 1.12, 4.46) of rs2867837 in TUSC7 had increased risk of GC susceptibility. The qRT-PCR showed that CA and AA genotype of rs12494960 in TUSC7 had significantly lower relative expression level in plasma, compared with CC genotype. The dual luciferase reporter assay showed that TUSC7 and miR-133a-3p had interaction.

CONCLUSION

The mutant genotype of rs12494960 could increase the susceptibility of gastric cancer and might affect the corresponding mRNA expression of lncRNA TUSC7 in plasma.

LncRNA HCG11/miR-579-3p/MDM2 axis modulates malignant biological properties in pancreatic carcinoma via Notch/Hes1 signaling pathway

BACKGROUND

Increasing reports have revealed that dysregulated expression of long non-coding RNAs (lncRNAs) is involved in pancreatic carcinoma progression. This study intends to explore the function and molecular mechanism of lncRNA HLA complex group 11 (HCG11) in pancreatic carcinoma.

METHODS

The expression profiles of HCG11 in pancreatic carcinoma samples were detected by qPCR. Bioinformatics analysis was applied to detect the associations among HCG11/miR-579-3p/MDM2. The malignant properties of pancreatic carcinoma cells were measured by numerous biological assays. Xenograft model was exploited to detect the effect of HCG11 on tumor growth.

RESULTS

A significant increase of HCG11 was occurred in pancreatic carcinoma samples. Knockdown of HCG11 suppressed the progression of pancreatic carcinoma cells. Bioinformatics analysis revealed that HCG11 upregulated MDM2 expression by competitively targeting miR-579-3p. The rescue assays showed that miR-579-3p reversed cell behaviors caused by HCG11, and MDM2 reversed cell properties induced by miR-579-3p. The Notch1 intracellular domain (NICD) and Hes1 protein levels were increased by overexpression of HCG11/MDM2. The tumor growth was suppressed after depletion of HCG11, followed by suppressing Ki67, PCNA and Vimentin expression, increasing TUNEL-positive cells and E-cadherin expression.

CONCLUSIONS

Our observations highlighted that HCG11 contributed to the progression of pancreatic carcinoma by promoting growth and aggressiveness, and inhibiting apoptosis via miR-579-3p/MDM2/Notch/Hes1 axis.

lncRNA TUSC7 inhibits osteosarcoma progression through the miR‑181a/RASSF6 axis

Osteosarcoma (OS) is one of the most aggressive malignancies, accompanied by an elevated incidence and a decreased rate of healing. Recently, several long non-coding RNAs (lncRNAs) have been reported to be involved in OS progression. Although tumor suppressor candidate 7 (TUSC7) was reported as a novel lncRNA, little is known about its biological functions in OS. The present study was designed to explore whether TUSC7 was involved in the pathological development of OS using various methods, including hematoxylin and eosin staining, Cell Counting Kit-8 assay, colony formation assay and Transwell assay. The present study revealed that TUSC7 expression was downregulated in OS tissues and cell lines compared with in normal tissues and cell lines. Functionally, the current results revealed that overexpression of TUSC7 inhibited OS cell proliferation, migration and invasion, while promoting apoptosis in vitro and in vivo. Next, the subcellular distribution of TUSC7 was examined by nuclear/cytoplasmic RNA fractionation and reverse transcription-quantitative PCR. Mechanistic studies revealed that TUSC7 exerted its role by sponging microRNA (miR)-181a in OS cell lines. Ras association domain family member 6 (RASSF6) was confirmed as a target gene of miR-181a, and the expression levels of RASSF6 were negatively regulated by miR-181a. Additionally, the results of rescue experiments suggested that overexpression of miR-181a neutralized the inhibitory effects of TUSC7 overexpression on OS cells. Overall, the present study demonstrated that the tumor suppressor role of TUSC7 in OS progression was mediated through the miR-181a/RASSF6 axis, which may represent a new therapeutic target for OS.

LncRNA MIR210HG Facilitates Non-Small Cell Lung Cancer Progression Through Directly Regulation of miR-874/STAT3 Axis

BACKGROUND

Long noncoding RNAs are involved in the progression of multiple cancers. However, the expression and mechanism of microRNA (miR)210HG in non-small cell lung cancer (NSCLC) remain unclear.

METHODS

The levels of miR210HG and miR-874 were measured by quantitative real-time polymerase chain reaction in NSCLC tissue samples and cells. Non-small cell lung cancer cell proliferation, migration, and invasion were measured by Cell Counting Kit-8 and transwell assays. Luciferase analysis confirmed the interaction between miR210HG and miR-874.

RESULTS

Here, our data showed that miR210HG was overexpressed in NSCLC tissue samples and cells. In vitro functional assays showed that silencing miR210HG blocked NSCLC cell proliferation, migration, and invasion while promoting NSCLC cell radiosensitivity and chemoresistance. Mechanistically, miR-874 was directly regulated by miR210HG. Furthermore, miR-874 expression was reduced in NSCLC tissues and cells. The miR-874 mimic could mitigate the promoting effect of miR210HG on NSCLC cell progression. The data also showed that miR210HG promoted NSCLC cell progression through miR-181a expression by targeting STAT3.

CONCLUSIONS

Our observations suggest that miR210HG is associated with NSCLC cell progression by regulating the miR-874/STAT3 axis.

Long non-coding RNA LINC01963 inhibits progression of pancreatic carcinoma by targeting miR-641/TMEFF2

PURPOSE

The aim of this study was to research the molecular mechanism of lncRNA LINC01963 in pancreatic carcinoma progression.

METHODS

Total 67 pancreatic cancer patients diagnosed and undergoing pancreatic cancer surgery in our hospital from April 2018 to April 2019 were included in this study. Pancreatic cancer cell lines including PANC-1, CFPAC-1, BxPC-3, SW1990 and AsPC1 were used. Based on bioinformatics information, pIRES2-LINC01963 plasmid, siLINC01963, miRNA mimics, miRNA inhibitor or siTMEFF2 were transfected. qRT-PCR and western blot were used to detect the expression of LINC01963, miR-641 and TMEFF2. CCK8 and Colony formation assay were processed for proliferation. Flow Cytometry Assay was processed to detect cell cycle and apoptosis. Transwell experiment was undertaken for invasion and migration. Luciferase assay and RNA Immunoprecipitation assay were used to verify the binding site among LINC01963, miR-641 and TMEFF2. Tumorigenic experiment was processed to confirm the above mechanisms in vivo.

RESULTS

lncRNA LINC01963 was confirmed to be lower expressed in pancreatic carcinoma tissues and cell lines. By up-regulating the expression of lncRNA LINC01963 in pancreatic carcinoma cell lines, colony number, cell cycle, proliferation and invasion were inhibited, while apoptosis was improved. More importantly, shLINC01963 could improve development of tumor in vivo. Besides, lncRNA LINC01963 negatively regulated the expression of miR-641, while miR-641 negatively targeted TMEFF2. Both miR-641 mimic and siTMEFF2 could reverse the effects of lncRNA LINC01963 overexpression in vitro.

CONCLUSIONS

Long non-coding RNA LINC01963 inhibits progression of pancreatic carcinoma by targeting miR-641/TMEFF2.

Inhibition of TUG1/miRNA-299-3p Axis Represses Pancreatic Cancer Malignant Progression via Suppression of the Notch1 Pathway

BACKGROUND AND AIMS

Taurine-upregulated gene 1 (TUG1) is reported to be upregulated and contributes to the progression of Pancreatic cancer (PC) by serving as an oncogene. Our aims were to explore the precise mechanism of TUG1 involved in PC pathogenesis.

METHODS

TUG1 and miR-299-3p expression profiles were measured by qRT-PCR. The direct interaction between TUG1 and miR-299-3p was explored by luciferase reporter assay. MTT assay, flow cytometry analysis, caspase-3 activity assay, Transwell invasion assay and wound healing assay were performed to evaluate cell proliferative ability, apoptosis, caspase-3 activity, invasion and migration, respectively. Western blot was conducted to examine the expressions of Ki67, Bax, Bcl-2, matrix metalloproteinase-2 (MMP-2), MMP-9, E-cadherin, N-cadherin, Snail, Notch1, Survivin, and CyclinD1. In addition, animal experiments were also implemented.

RESULTS

TUG1 was highly expressed, while miR-299-3p was underexpressed in PC tissues and PC cells. Furthermore, the significant increase of TUG1 in PC tissues of advanced patients (stage 3/4) was observed compared to patients (stage 1/2). TUG1 was negatively correlated with miR-299-3p expression in PC tissues. Moreover, TUG1 functioned as a molecular sponge of miR-299-3p to repress its expression. TUG1 knockdown suppressed cell proliferation, invasion, migration, and epithelial-mesenchymal transition (EMT), and induced apoptosis in PC cells, and repressed tumor growth and EMT in PC xenograft models, which were reversed following reintroduction with anti-miR-299-3p. Furthermore, we found that TUG1 silencing inactivated the Notch1 pathway in PC by upregulating miR-299-3p.

CONCLUSIONS

The results reported that inhibition of TUG1/miR-299-3p axis suppressed PC malignant progression via suppression of the Notch1 pathway.

Identification of key lncRNAs in the tumorigenesis of intraductal pancreatic mucinous neoplasm by coexpression network analysis

Intraductal papillary mucinous neoplasm (IPMN) is an intraepithelial precancerous lesion of pancreatic ductal adenocarcinoma (PDAC) that progresses from adenoma to carcinoma, and long noncoding RNAs (lncRNA) might be involved in the tumorigenesis. In this study, we obtained the expression profiles of more than 4000 lncRNAs by probe reannotation of a microarray dataset. As a correlation network‐based systems biology method, weighted gene coexpression network analysis (WGCNA) was used to find clusters of highly correlated lncRNAs in the tumorigenesis of IPMN, which covered four stepwise stages from normal main pancreatic duct to invasive IPMN. In the most relevant module (R² = −0.75 and P = 5E‐05), three hub lncRNAs were identified (HAND2‐AS1, CTD‐2033D15.2, and lncRNA‐TFG). HAND2‐AS1 and CTD‐2033D15.2 were negatively correlated with the tumorigenesis (P in one‐way ANOVA test = 1.45E‐07 and 1.39E‐0.5), while lncRNA‐TFG were positively correlated with the tumorigenesis (P = 3.99E‐08). The validation set reached consistent results (P = 2.66E‐03 in HAND2‐AS1, 1.47E‐04 in CTD‐2033D15.2 and 6.23E‐08 in lncRNA‐TFG). In functional enrichment analysis, the target genes of microRNAs targeting also these lncRNAs were overlapped in multiple biological processes, pathways and malignant diseases including pancreatic cancer. In survival analysis, patients with higher expression of HAND2‐AS1‐targeted and CTD‐2033D15.2‐targeted microRNAs showed a significantly poorer prognosis in PDAC, while high expression of lncRNA‐TFG‐targeted microRNAs demonstrated an obviously better prognosis (log‐rank P < .05). In conclusion, by coexpression network analysis of the lncRNA profiles, three key lncRNAs were identified in association with the tumorigenesis of IPMN, and those lncRNAs might act as early diagnostic biomarkers or therapeutic targets in pancreatic cancer.

The novel long noncoding RNA CRART16 confers cetuximab resistance in colorectal cancer cells by enhancing ERBB3 expression via miR-371a-5p

Background

Long noncoding RNAs (lncRNAs) have been shown to participate in multiple biological processes and confer drug resistance. However, it remains unclear whether lncRNAs are involved in conferring cetuximab resistance in colorectal cancer (CRC) cells.

Methods

Cell Counting Kit-8 (CCK-8) assays were performed to assess the sensitivity of CRC cell lines to cetuximab treatment. We incubated Caco-2 cells, which are partially responsive to cetuximab, with increasing concentrations of cetuximab for approximately 6 months to generate Caco-2 cetuximab-resistant (Caco-2 CR) cells. Microarray analysis comparing Caco-2 CR with Caco-2 cells was used to identify lncRNAs that were potentially related to cetuximab resistance. Caco-2 cells were stably transduced with cetuximab resistance-associated RNA transcript 16 (CRART16) or an empty vector using lentiviral infection; the cells were designated Caco-2-CRART16 and Caco-2-NC, respectively, and were analyzed with RNA sequencing (RNA-seq). Quantitative real-time PCR (qRT-PCR) was performed to investigate RNA expression. Flow cytometry and TUNEL assays were used to assess apoptosis levels induced by cetuximab. The cell cycle, stemness biomarkers and membrane proteins of CRC cells were assessed via flow cytometry. RNA fluorescence in situ hybridization (FISH) was used to examine CRART16 localization and expression. Bioinformatics analysis was performed to predict the potential mechanism of CRART16, which was further validated by a dual-luciferase reporter assay. Differences in measurement data were compared using Student’s t test, one-way ANOVA followed by Dunnett’s test and two-way ANOVA.

Results

The novel lncRNA CRART16 was upregulated in Caco-2 CR cells. CRART16 overexpression reversed the effects of cetuximab on cell viability and reduced cetuximab-induced apoptosis. Meanwhile, CRART16 overexpression led to increases in the proportion of CD44⁺/CD133⁺ cells. In addition, CRART16 acts as a competing endogenous RNA (ceRNA) for miR-371a-5p to regulate V-Erb-B2 Erythroblastic Leukemia Viral Oncogene Homolog 3 (ERBB3) expression. MiR-371a-5p mimics counteracted the cetuximab resistance induced by CRART16 overexpression. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that after CRART16 was overexpressed, the resulting differentially expressed mRNAs were mainly enriched in the MAPK signaling pathway.

Conclusions

CRART16 overexpression may contribute to cetuximab resistance through the miR-371a-5p/ERBB3/MAPK pathway. Additionally, CRART16 contributes to the acquisition of stemness properties.

LSAMP-AS1 binds to microRNA-183-5p to suppress the progression of prostate cancer by up-regulating the tumor suppressor DCN

Background

: Prostate cancer (PCa) is a leading cause of cancer-related death in males. Aberrant expression of long noncoding RNAs (lncRNAs) is frequently reported in human malignancies. This study was performed to explore the role of LSAMP-AS1 in epithelial-mesenchymal transition (EMT), proliferation, migration and invasion of PCa cells.

Methods

: Initially, the differentially expressed lncRNAs in PCa were screened out by microarray analysis. The clinicopathological and prognostic significance of LSAMP-AS1 was evaluated. LSAMP-AS1 was over-expressed or silenced to investigate the roles in EMT, proliferation, migration and invasion of PCa cells. Moreover, the relationships between LSAMP-AS1 and miR-183–5p, as well as miR-183–5p and decorin (DCN) were characterized. The tumorigenicity of PCa cells was verified in nude mice.

Results

: LSAMP-AS1 was poorly expressed in PCa tissues and cells. Low expression of LSAMP-AS1 was indicative of poor overall survival and disease-free survival, and related to Gleason score, TNM stage, and risk stratification. Over-expressed LSAMP-AS1 inhibited EMT, proliferation, migration and invasion of PCa cells, as well as tumor growth in nude mice. Meanwhile, over-expression of LSAMP-AS1 resulted in up-regulation of E-cadherin and down-regulation of Vimentin, N-cadherin, Ki67, PCNA, MMP-2, MMP-9, Ezrin and Fascin. Notably, LSAMP-AS1 competitively bound to miR-183–5p which directly targets DCN. It was confirmed that the inhibitory effect of LSAMP-AS1 on PCa cells was achieved by binding to miR-183–5p, thus promoting the expression of DCN.

Conclusion

: LSAMP-AS1 up-regulates the DCN gene by competitively binding to miR-183–5p, thus inhibiting EMT, proliferation, migration and invasion of PCa cells.

Long non-coding RNA MACC1-AS1 promoted pancreatic carcinoma progression through activation of PAX8/NOTCH1 signaling pathway

BACKGROUND

Accumulated evidences have demonstrated that long non-coding RNAs (lncRNAs) are dysregulated and correlate with the pathophysiological basis of malignant tumors. The objective of this research is to uncover the possible molecular mechanism of MACC1-AS1 regarding the regulation of pancreatic carcinoma (PC) metastasis.

METHODS

lncRNA microarray and qRT-PCR were applied to identify differentially expressed lncRNA profile in PC. The function and role of MACC1-AS1 in PC were assessed via in vitro as well as in vivo assays. Luciferase analyses, RNA immunoprecipitation, and RNA pull-down were performed to determined the underlying MACC1-AS1 mechanisms.

RESULTS

Numbers of differentially expressed lncRNAs in PC were identified via lncRNA microarrays, among which MACC1-AS1 was revealed as the most abundant lncRNA. The upregulation of MACC1-AS1 in PC was further confirmed in two expanded PC cohorts, which showed that MACC1-AS1 expression was upregulated in those PC patients with poor survival. Functionally, knockdown of MACC1-AS1 inhibited the proliferation as well as metastasis of PC cells. Meanwhile, MACC1-AS1 upregulated the expression of PAX8 protein, which promoted aerobic glycolysis and activated NOTCH1 signaling. Additionally, PAX8 was upregulated in PC tissues, which was correlated with the expression of MACC1-AS1 and the overall survival of PC patients.

CONCLUSIONS

Together, our findings indicate a critical role of MACC1-AS1/PAX8/NOTCH1 signaling, which may be an alternative treatment target in PC therapy.

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 and Epithelial Mesenchymal Transition in Cancer

Epithelial-mesenchymal transition (EMT) is a multistep process that allows epithelial cells to acquire mesenchymal properties. Fundamental in the early stages of embryonic development, this process is aberrantly activated in aggressive cancerous cells to gain motility and invasion capacity, thus promoting metastatic phenotypes. For this reason, EMT is a central topic in cancer research and its regulation by a plethora of mechanisms has been reported. Recently, genomic sequencing and functional genomic studies deepened our knowledge on the fundamental regulatory role of noncoding DNA. A large part of the genome is transcribed in an impressive number of noncoding RNAs. Among these, long noncoding RNAs (lncRNAs) have been reported to control several biological processes affecting gene expression at multiple levels from transcription to protein localization and stability. Up to now, more than 8000 lncRNAs were discovered as selectively expressed in cancer cells. Their elevated number and high expression specificity candidate these molecules as a valuable source of biomarkers and potential therapeutic targets. Rising evidence currently highlights a relevant function of lncRNAs on EMT regulation defining a new layer of involvement of these molecules in cancer biology. In this review we aim to summarize the findings on the role of lncRNAs on EMT regulation and to discuss their prospective potential value as biomarkers and therapeutic targets in cancer.