Long non-coding RNA PXN-AS1 suppresses pancreatic cancer progression by acting as a competing endogenous RNA of miR-3064 to upregulate PIP4K2B expression

Engineering CRISPR/Cas9 therapeutics for cancer precision medicine

The discovery of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) technology has revolutionized field of cancer treatment. This review explores usage of CRISPR/Cas9 for editing and investigating genes involved in human carcinogenesis. It provides insights into the development of CRISPR as a genetic tool. Also, it explores recent developments and tools available in designing CRISPR/Cas9 systems for targeting oncogenic genes for cancer treatment. Further, we delve into an overview of cancer biology, highlighting key genetic alterations and signaling pathways whose deletion prevents malignancies. This fundamental knowledge enables a deeper understanding of how CRISPR/Cas9 can be tailored to address specific genetic aberrations and offer personalized therapeutic approaches. In this review, we showcase studies and preclinical trials that show the utility of CRISPR/Cas9 in disrupting oncogenic targets, modulating tumor microenvironment and increasing the efficiency of available anti treatments. It also provides insight into the use of CRISPR high throughput screens for cancer biomarker identifications and CRISPR based screening for drug discovery. In conclusion, this review offers an overview of exciting developments in engineering CRISPR/Cas9 therapeutics for cancer treatment and highlights the transformative potential of CRISPR for innovation and effective cancer treatments.

Long non-coding RNAs and pancreatic cancer: A multifaceted view

Pancreatic cancer (PC) is a highly malignant disease with a 5-year survival rate of only 10%. Families with PC are at greater risk, as are type 2 diabetes, pancreatitis, and other factors. Insufficient early detection methods make this cancer have a poor prognosis. Additionally, the molecular mechanisms underlying PC development remain unclear. Increasing evidence suggests that long non-coding RNAs (lncRNAs) contribute to PC pathology,which may control gene expression by recruiting histone modification complexes to chromatin and interacting with proteins and RNAs. In recent studies, abnormal regulation of lncRNAs has been implicated in PC proliferation, metastasis, invasion, angiogenesis, apoptosis, and chemotherapy resistance suggesting potential clinical implications. The paper reviews the progress of lncRNA research in PC about diabetes mellitus, pancreatitis, cancer metastasis, tumor microenvironment regulation, and chemoresistance. Furthermore, lncRNAs may serve as potential therapeutic targets and biomarkers for PC diagnosis and prognosis. This will help improve PC patients' survival rate from a lncRNA perspective.

Optimization of CRISPR-Cas system for clinical cancer therapy

Cancer is a genetic disease caused by alterations in genome and epigenome and is one of the leading causes for death worldwide. The exploration of disease development and therapeutic strategies at the genetic level have become the key to the treatment of cancer and other genetic diseases. The functional analysis of genes and mutations has been slow and laborious. Therefore, there is an urgent need for alternative approaches to improve the current status of cancer research. Gene editing technologies provide technical support for efficient gene disruption and modification in vivo and in vitro, in particular the use of clustered regularly interspaced short palindromic repeats (CRISPR)-Cas systems. Currently, the applications of CRISPR-Cas systems in cancer rely on different Cas effector proteins and the design of guide RNAs. Furthermore, effective vector delivery must be met for the CRISPR-Cas systems to enter human clinical trials. In this review article, we describe the mechanism of the CRISPR-Cas systems and highlight the applications of class II Cas effector proteins. We also propose a synthetic biology approach to modify the CRISPR-Cas systems, and summarize various delivery approaches facilitating the clinical application of the CRISPR-Cas systems. By modifying the CRISPR-Cas system and optimizing its in vivo delivery, promising and effective treatments for cancers using the CRISPR-Cas system are emerging.

SOX21-AS1 activated by STAT6 promotes pancreatic cancer progression via up-regulation of SOX21

Background

Pancreatic cancer (PC) is a highly malignant tumor which threatens human’s health. Long non-coding RNAs (lncRNAs) are implicated in many cancers, including PC, but their mechanisms in PC have not yet been entirely clarified. We focused on revealing the potential function of lncRNA SOX21-AS1 in PC.

Methods

Functional assays assessed SOX21-AS1 function on PC progression. Bioinformatics analysis, along with mechanism assays were taken to unmask the regulatory mechanism SOX21-AS1 may exert in PC cells.

Results

SOX21-AS1 possessed a high expression level in PC cells. SOX21-AS1 absence suppressed PC cell proliferation, migration, stemness and epithelial-mesenchymal transition (EMT) while elevated cell apoptosis. SOX21-AS1 positively regulated its nearby gene SRY-box transcription factor 21 (SOX21) at post-transcriptional level. Through mechanism assays, we uncovered that SOX21-AS1 sponged SOX21-AS1 to elevate SOX21 mRNA and recruited ubiquitin-specific peptidase 10 (USP10) to deubiquitinate and stabilize SOX21 protein. Moreover, signal transducer and activator of transcription 6 (STAT6) could transcriptionally activate SOX21-AS1 and SOX21 expression.

Conclusions

SOX21-AS1 aggravated the malignant development of PC, which might provide the utility value for PC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03521-5.

Positive feedback regulation of lncRNA TPT1-AS1 and ITGB3 promotes cell growth and metastasis in pancreatic cancer

Emerging evidence has indicated that long noncoding RNAs (lncRNAs) are potential biomarkers and play crucial roles in cancer development. However, the functions and underlying mechanisms of lncRNA TPT1-AS1 in pancreatic ductal adenocarcinoma (PDAC) remain elusive. RNAseq data of PDAC tissues and normal tissues were analyzed, and lncRNAs which were associated with PDAC prognosis were identified. The clinical relevance of TPT1-AS1 for PDAC patients was explored, and the effects of TPT1-AS1 in PDAC progression were investigated in vitro and in vivo. LncRNA TPT1-AS1 was highly expressed in PDAC, and high TPT1-AS1 levels predicted a poor prognosis. Moreover, functional experiments revealed that TPT1-AS1 promoted pancreatic cancer cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) process in vitro and in vivo. Mechanistically, TPT1-AS1 functioned as an endogenous sponge for miR-30a-5p, which increased integrin β3 (ITGB3) level in pancreatic cancer cells. Conversely, our data revealed that ITGB3 could activate the transcription factor signal transducer and activator of transcription 3 (STAT3), which in turn bound directly to the TPT1-AS1 promoter and affected the expression of TPT1-AS1, thus forming a positive feedback loop with TPT1-AS1. Taken together, our results uncovered a reciprocal loop of TPT1-AS1 and ITGB3 which contributed to pancreatic cancer growth and development, and indicated that TPT1-AS1 might serve as a novel potential diagnostic biomarker and therapeutic target for PDAC patients.

The Roles of MicroRNA in Pancreatic Cancer Progression

Pancreatic Ductal Adenocarcinoma (PDAC) has a poor patient survival rate in comparison with other cancer types, even after targeted therapy, chemotherapy, and immunotherapy. Therefore, a great deal needs to be done to gain a better understanding of the biology and identification of prognostic and predictive markers for the development of superior therapies. The microRNAs (miRNAs) belong to small non-coding RNAs that regulate post-transcriptional gene expression. Several shreds of evidence indicate that miRNAs play an important role in the pathogenesis of pancreatic cancer. Here we review the recent developments in miRNAs and their target role in the development, metastasis, migration, and invasion.

A Novel Identified Long Intergenic Noncoding RNA, LINC01574, Contributes to Breast Cancer Deterioration via the Regulation of miR-6745/TTYH3 Axis

Objective

Compelling evidence suggested that lncRNAs performed vital functions in the development of breast cancer (BC). The study intended to mine the functional roles of LINC01574 in BC and further excavated its underlying regulatory mechanism.

Methods

The expression and prognosis of LINC01574 in BC were detected by integrating analysis of data mining, bioinformatics, and RT-qPCR. Then, the effect of LINC01574 knockdown on BC cell growth and metastasis was evaluated in vitro and in vivo. Interactions between miR-6745 and LINC01574 or TTYH3 were revealed by both target prediction and dual luciferase reporter assay.

Results

Our data found that LINC01574 was markedly elevated in BC tissues and cells and was an independent prognostic risk factor for patients with BC. Further functional studies revealed that knockdown of LINC01574 remarkably inhibited the growth and metastasis of BC cells in vitro and in vivo. Mechanistically, LINC01574 competitively binds with miR-6745 to prevent the degradation of TTYH3, thereby promoting the development of BC.

Conclusion

Our results unmasked a novel LINC01574/miR-6745/TTYH3 regulatory axis in BC progression and suggested that LINC01574 might be a promising prognostic indicator and therapeutic target for patients with BC.

PLAC8 Overexpression Promotes Lung Cancer Cell Growth via Wnt/β-Catenin Signaling

The PLAC8 expression in lung cancer tissues and in vitro grown lung cancer cells, as well as the involvement of the Wnt/β-Catenin signaling pathway, was investigated in this process. PLAC8 protein expression in human lung cancer tissues and lung tumor cells of different strains was discovered using immunohistochemistry staining and Western blot, respectively. Animal models of PLAC8 overexpression and knockdown were created using lentivirus. The development in tumor tissue was seen both in vitro and vivo. The Wnt/β-Catenin signaling pathway played an important part in this process, as shown by the dual luciferase reporter gene system. PLAC8 expression was elevated in lung cancer tissues and plasma and decreased in plasma after lung tumor resection. PLAC8 upregulation promotes cell proliferation in vivo and in vitro, while PLAC8 downregulation inhibits cell viability and proliferation. The results of the dual luciferase reporter gene system suggest that PLAC8 can significantly activate the Wnt/β-Catenin signaling pathway in cells and can conduct signaling through it. A potential treatment targeting the prognosis of lung cancer patients may be PLAC8 overexpression, which promotes the lung cancer cell proliferation through controlling the Wnt/β-Catenin signaling pathway.

DDX17-regulated alternative splicing that produced an oncogenic isoform of PXN-AS1 to promote HCC metastasis

BACKGROUND AND AIMS

The mechanism underlying HCC metastasis remains unclear, many oncogenes are known to regulate this process. However, the role of alternative splicing (AS) in pro-metastatic HCC is poorly understood.

APPROACH AND RESULTS

By performing RNA sequencing on nine pairs of primary HCC tissues with extrahepatic metastasis (EHMH) and nine pairs of metastasis-free HCC (MFH) tissues, we depicted the AS landscape in HCC and found a higher frequency of AS events in EHMH compared with MFH. Moreover, 28 differentially expressed splicing regulators were identified in EHMH compared with MFH. Among these, DEAD-box RNA helicase 17 (DDX17) was significantly up-regulated in EHMH and was strongly associated with patient outcome. Functional studies indicated that DDX17 knockout inhibited the degradation of the extracellular matrix, and diminished the invasive ability of HCC cells. A significant reduction in lung metastasis induced by DDX17 deficiency was also demonstrated in a diethylnitrosamine-induced DDX17^HKO mouse model. Mechanistically, high DDX17 induced intron 3 retention of PXN-AS1 and produced a transcript (termed PXN-AS1-IR3). The transcript PXN-AS1-IR3 acted as an important promoter of HCC metastasis by inducing MYC transcription activation via recruiting the complex of testis expressed 10 and p300 to the MYC enhancer region, which led to transcriptional activation of several metastasis-associated downstream genes. Finally, the PXN-AS1-IR3 level was significantly higher in serum and HCC tissues with extrahepatic metastasis.

CONCLUSIONS

DDX17 and PXN-AS1-IR3 act as important metastatic promoters by modulating MYC signaling, suggesting that DDX17 and PXN-AS1-IR3 may be potential prognostic markers for metastatic HCC.

Ferroptosis-Related IncRNAs Are Prognostic Biomarker of Overall Survival in Pancreatic Cancer Patients

Pancreatic cancer (PC) is one of the most lethal malignancies, the mortality and morbidity of which have been increasing over the past decade. Ferroptosis, a newly identified iron-dependent cell death pattern, can be induced by iron chelators and small lipophilic antioxidants. Nonetheless, the prognostic significance of ferroptosis-related lncRNAs in PC remains to be clarified. We obtained the lncRNA expression matrix and clinicopathological information of PC patients from The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) datasets in the current study. Firstly, we conducted Pearson correlation analysis to delve into the ferroptosis-related lncRNAs, and univariate Cox analysis was implemented to examine the prognostic values in PC patients. Twenty-three prognostic ferroptosis-related lncRNAs were confirmed and loaded into the least absolute shrinkage and selection operator Cox (LASSO-Cox) analysis, then a ferroptosis-related lncRNA prognostic marker (Fe-LPM) was established in the TCGA dataset. Risk scores of patients were calculated and segregated PC patients into low-risk and high-risk subgroups in each dataset. The prognostic capability of Fe-LPM was also confirmed in the ICGC dataset. Gene set enrichment analysis (GSEA) revealed that several ferroptosis-related pathways were enriched in low-risk subgroups. Furthermore, we adopted a multivariate Cox regression to establish a nomogram based on risk score, age, pathological T stage and primary therapy outcome. A competing endogenous RNA (ceRNA) network was also created relied on four of the twenty-three ferroptosis-related lncRNAs. In conclusion, the eight Fe-LPM can be utilized to anticipate the overall survival (OS) of PC patients, which are meaningful to guiding clinical strategies in PC.

Identification of miR-199-5p and miR-199-3p Target Genes: Paxillin Facilities Cancer Cell Aggressiveness in Head and Neck Squamous Cell Carcinoma

Our previous study revealed that the miR-199 family (miR-199a-5p/-3p and miR-199b-5p/-3p) acts as tumor-suppressive miRNAs in head and neck squamous cell carcinoma (HNSCC). Furthermore, recent studies have indicated that the passenger strands of miRNAs are involved in cancer pathogenesis. The aim of this study was to identify cancer-promoting genes commonly regulated by miR-199-5p and miR-199-3p in HNSCC cells. Our in silico analysis and luciferase reporter assay identified paxillin (PXN) as a direct target of both miR-199-5p and miR-199-3p in HNSCC cells. Analysis of the cancer genome atlas (TCGA) database showed that expression of PXN significantly predicted a worse prognosis (5-year overall survival rate; p = 0.0283). PXN expression was identified as an independent factor predicting patient survival according to multivariate Cox regression analyses (p = 0.0452). Overexpression of PXN was detected in HNSCC clinical specimens by immunostaining. Functional assays in HNSCC cells showed that knockdown of PXN expression attenuated cancer cell migration and invasion, suggesting that aberrant expression of PXN contributed to HNSCC cell aggressiveness. Our miRNA-based approach will provide new insights into the molecular pathogenesis of HNSCC.

Extracellular Vesicles Long Non-Coding RNA AGAP2-AS1 Contributes to Cervical Cancer Cell Proliferation Through Regulating the miR-3064-5p/SIRT1 Axis

Cervical cancer is one of the most severe and prevalent female malignancies and a global health issue. The molecular mechanisms underlying cervical cancer development are poorly investigated. As a type of extracellular membrane vesicles, EVs from cancer cells are involved in cancer progression by delivering regulatory factors, such as proteins, microRNAs (miRNAs), and long non-coding RNAs (lncRNAs). In this study, we identified an innovative function of extracellular vesicle (EV) lncRNA AGAP2-AS1 in regulating cervical cancer cell proliferation. The EVs were isolated from the cervical cancer cells and were observed by transmission electron microscopy (TEM) and were confirmed by analyzing exosome markers. The depletion of AGAP2-AS1 by siRNA significantly reduced its expression in the exosomes from cervical cancer and in the cervical cancer treated with AGAP2-AS1-knockdown exosomes. The expression of AGAP2-AS1 was elevated in the clinical cervical cancer tissues compared with the adjacent normal tissues. The depletion of EV AGAP2-AS1 reduced cell viabilities and Edu-positive cervical cancer cells, while it enhanced cervical cancer cell apoptosis. Tumorigenicity analysis in nude mice showed that the silencing of EV AGAP2-AS1 attenuated cervical cancer cell growth in vivo. Regarding the mechanism, we identified that AGAP2-AS1 increased SIRT1 expression by sponging miR-3064-5p in cervical cancer cells. The overexpression of SIRT1 or the inhibition of miR-3064-5p reversed EV AGAP2-AS1 depletion-inhibited cancer cell proliferation in vitro. Consequently, we concluded that EV lncRNA AGAP2-AS1 contributed to cervical cancer cell proliferation through regulating the miR-3064-5p/SIRT1 axis. The clinical values of EV lncRNA AGAP2-AS1 and miR-3064-5p deserve to be explored in cervical cancer diagnosis and treatments.

Long non-coding RNA LINC00958 promotes colorectal cancer progression by enhancing the expression of LEM domain containing 1 via microRNA miR-3064-5p

Colorectal cancer is a common cause of cancer-related death worldwide. Thus, there is an urgent need to determine the mechanism of progression of colorectal cancer. In this study, we investigated the function and mechanism of long non-coding RNA LINC00958, providing a new biomarker for colorectal cancer. The expression of LINC00958, miR-3064-5p, and LEM domain containing 1 (LEMD1) in colorectal cancer tissues and cell lines was analyzed using reverse transcription quantitative polymerase chain reaction (RT-qPCR). The interaction between LINC00958, miR-3064-5p, and LEMD1 was assessed using the luciferase assay. The viability, proliferation, migration, invasion, and apoptosis of colorectal cancer cells with silenced LINC00958, miR-3064-5p, and LEMD1 were investigated using the cell counting kit-8 (CCK-8), 5′-Bromo-2′-deoxyuridine (BrdU), flow cytometry, wound healing, and transwell assays. Phosphorylated phosphoinositide 3-kinase (p-PI3K) and phosphorylated protein kinase B (p-AKT) protein levels were measured by western blotting. LINC00958 and LEMD1 were found to have increased, while the expression of miR-3064-5p was decreased in colorectal cancer tissues and cell lines. Silencing of LINC00958 hampered cell viability, proliferation, migration, and invasion, while enhancing the apoptosis in colorectal cancer cells. Notably, LINC00958 inhibited miR-3064-5p and promoted LEMD1; the miR-3064-5p inhibitor abrogated the effect of LINC00958 silencing in colorectal cancer cells. Additionally, LEMD1 knockdown inhibited the activation of PI3K/AKT signaling. Our analyses have shown that LINC00958 could facilitate the progression of colorectal cancer by sponging miR-3064-5p and releasing LEMD1, leading to the activation of the PI3K/AKT pathway. Thus, LINC00958 may be considered as an effective biomarker for the treatment of colorectal cancer.

Application of the CRISPR/Cas9-based gene editing technique in basic research, diagnosis, and therapy of cancer

The 2020 Nobel Prize in Chemistry was awarded to Emmanuelle Charpentier and Jennifer Doudna for the development of the Clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease9 (CRISPR/Cas9) gene editing technology that provided new tools for precise gene editing. It is possible to target any genomic locus virtually using only a complex nuclease protein with short RNA as a site-specific endonuclease. Since cancer is caused by genomic changes in tumor cells, CRISPR/Cas9 can be used in the field of cancer research to edit genomes for exploration of the mechanisms of tumorigenesis and development. In recent years, the CRISPR/Cas9 system has been increasingly used in cancer research and treatment and remarkable results have been achieved. In this review, we introduced the mechanism and development of the CRISPR/Cas9-based gene editing system. Furthermore, we summarized current applications of this technique for basic research, diagnosis and therapy of cancer. Moreover, the potential applications of CRISPR/Cas9 in new emerging hotspots of oncology research were discussed, and the challenges and future directions were highlighted.

A novel long non-coding RNA TTN-AS1/microRNA-589-5p/FOXP1 positive feedback loop increases the proliferation, migration and invasion of pancreatic cancer cell lines

Numerous reports have found that long non-coding (lnc) RNAs were associated with pancreatic cancer (PC) initiation and development. The lncRNA titin antisense RNA 1 (TTN-AS1) was identified as a tumor promoter in certain types of cancer; however, its role and mechanism in PC remain unclear. The aim of the present study was to investigate the role of TTN-AS1 in PC and elucidate the underlying mechanism. Reverse transcription-quantitative PCR analysis was performed to examine the mRNA expression level of TTN-AS1, microRNA(miR)-589-5p and forkhead box protein 1 (FOXP1). Knockdown experiments were performed to examine the effect of TTN-AS1 on PC cell proliferation, migration and invasion. Luciferase reporter assays validated the binding of miR-589-5p to TTN-AS1 and FOXP1. Chromatin immunoprecipitation and luciferase reporter assays confirmed the binding ability of FOXP1 to the TTN-AS1 promoter. As a result, TTN-AS1 and FOXP1 were found to be upregulated in PC cell lines and tissues, while miR-589-5p was expressed at low levels. Knockdown experiments indicated the suppressive effect of TTN-AS1 knockdown on cell proliferation, migration and invasion in PC cell lines. Further mechanistic research uncovered that TTN-AS1 functioned as a molecular sponge for miR-589-5p and its mRNA expression level in PC tissues was inversely associated with that of miR-589-5p. Furthermore, miR-589-5p was confirmed to target FOXP1. Of note, it was discovered that FOXP1 transcriptionally activated TTN-AS1 mRNA expression level. Taken together, the findings of the present study demonstrated that the new TTN-AS1/miR-589-5p/FOXP1 feedback loop may play an important role in PC.

Long noncoding RNA LINC00858 promotes the progression of ovarian cancer via regulating the miR-134-5p/TRIM44 axis

Recent studies have shown that many long noncoding RNAs (lncRNAs) are abnormally expressed in ovarian cancer and involved in the pathological progress of ovarian cancer. In the present study, we aimed to investigate the role of lncRNA LINC00858 and the potential mechanism in ovarian cancer. The qRT-PCR was used to measure the expression levels of LINC00858 and miR-134-5p in ovarian cancer tissue specimens and cell lines. Loss-of-function assays were performed to investigate the role of LINC00858 in ovarian cancer. MTT assay was carried out to measure cell proliferation. Transwell assays were performed to determine cell migration and invasion. Biological information analysis and luciferase report gene assay were used to verify potential downstream genes of LINC00858. The xenograft mouse model was established to analyze tumor growth in vivo. Our results showed that LINC00858 was highly expressed in human ovarian cancer tissues and cell lines. Knockdown of LINC00858 inhibited cell proliferation, migration and invasion of SKOV3 cells, and suppressed tumor growth in mouse xenograft models. Mechanistic studies revealed that LINC00858 acted as a sponge of miR-134-5p and then regulated TRIM44 expression in SKOV3 cells. Furthermore, rescue experiments illustrated that inhibition of miR-134-5p restored the inhibitory effects of LINC00858 knockdown on cell proliferation, migration and invasion. TRIM44 overexpression could counteract the inhibitory effects of miR-134-5p mimics on ovarian cancer cells. In conclusion, these findings demonstrated that LINC00858 exerted oncogenic role in ovarian cancer, which was mediated by miR-134-5p/TRIM44 axis. Thus, LINC00858 might be a therapeutic target for the treatment of ovarian cancer.

lncRNA SNHG22 sponges miR‑128‑3p to promote the progression of colorectal cancer by upregulating E2F3

The long non‑coding RNA (lncRNA) small nucleolar RNA host gene 22 (SNHG22) has been reported as a crucial regulator in several types of human cancer. The present study evaluated the function and mechanism of SNHG22 in colorectal cancer (CRC) progression. SNHG22 expression was detected in colorectal adenoma, CRC tumor tissues (TTs) and adjacent non‑cancerous tissues (ANTs) using reverse transcription‑quantitative PCR (RT‑qPCR). The biological behaviors of SNHG22 in CRC cell lines were explored in vitro using Cell Counting Kit‑8, flow cytometry, wound scratch assay and Transwell assay, and in vivo using a nude mouse xenograft model. The interaction between SNHG22 and microRNA‑128‑3p (miR‑128‑3p), and the target genes of miR‑128‑3p were explored using online tools, RT‑qPCR, western blotting and a dual‑luciferase reporter assay. The present study revealed that SNHG22 expression was most highly expressed in TTs followed by adenoma tissues and ANTs. In addition, high SNHG22 expression levels were significantly associated with advanced clinicopathological factors and worse survival in patients with CRC. SNHG22 knockdown markedly inhibited CRC cell proliferation, apoptosis resistance, migration and invasion in vitro, and hindered tumor growth in vivo. The mechanistic study revealed that SNHG22 bound to miR‑128‑3p and attenuated its inhibitory effects on E2F transcription factor 3 (E2F3) expression levels and activity. Rescue experiments demonstrated that inhibiting miR‑128‑3p or upregulating E2F3 offset the effects of SNHG22 knockdown on CRC cells. The present findings support the existence of an interactive regulatory network involving SNHG22, miR‑128‑3p and E2F3 in CRC cell lines, indicating that the SNHG22/miR‑128‑3p/E2F3 axis may be considered a novel diagnostic and therapeutic target in CRC.

Review of applications of CRISPR-Cas9 gene-editing technology in cancer research

Characterized by multiple complex mutations, including activation by oncogenes and inhibition by tumor suppressors, cancer is one of the leading causes of death. Application of CRISPR-Cas9 gene-editing technology in cancer research has aroused great interest, promoting the exploration of the molecular mechanism of cancer progression and development of precise therapy. CRISPR-Cas9 gene-editing technology provides a solid basis for identifying driver and passenger mutations in cancer genomes, which is of great value in genetic screening and for developing cancer models and treatments. This article reviews the current applications of CRISPR-Cas9 gene-editing technology in various cancer studies, the challenges faced, and the existing solutions, highlighting the potential of this technology for cancer treatment.

DNMT1 Mediated CAHM Repression Promotes Glioma Invasion via SPAK/JNK Pathway

Gliomas are the most common and fatal brain tumors worldwide. Abnormal DNA promoter methylation is an important mechanism for gene loss of tumor suppressors. A long non-coding RNA colorectal adenocarcinoma hypermethylated (CAHM) has been reported to be nearly deleted in glioblastomas (GBMs). Nevertheless, the roles of CAHM in gliomas remain unknown up to now. In the present study, 969 glioma samples downloaded from the CGGA and Gravendeel databases were included. We found that CAHM expression was correlated with glioma grades, molecular subtype, IDH mutation status, and 1q/19p codel status. In glioma cells, CAHM is hypermethylated by DNA methyltransferase1 (DNMT1) and the loss of CAHM expression could be reversed by 5-Aza-2'-deoxycytidine (5-Aza), a specific inhibitor of DNA methyltransferases. Besides, the expression of CAHM was negatively associated with overall survival in both primary and recurrent gliomas. Moreover, the result of Gene Ontology (GO) analysis suggested that CAHM participated in negatively regulating cell development, nervous system development, neurogenesis, and integrin-mediated signaling pathway. Overexpression of CAHM inhibited glioma cell proliferation, clone formation, and invasion. Further exploring results showed that CAHM overexpression suppressed glioma migration and invasion through SPAK/MAPK pathway. Collectively, this study disclosed that CAHM might be a suppressor in gliomas.

Non-coding RNAs in pancreatic ductal adenocarcinoma: New approaches for better diagnosis and therapy

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies with a 5-year survival rate less than 8%, which has remained unchanged over the last 50 years. Early detection is particularly difficult due to the lack of disease-specific symptoms and a reliable biomarker. Multimodality treatment including chemotherapy, radiotherapy (used sparingly) and surgery has become the standard of care for patients with PDAC. Carbohydrate antigen 19-9 (CA 19-9) is the most common diagnostic biomarker; however, it is not specific enough especially for asymptomatic patients. Non-coding RNAs are often deregulated in human malignancies and shown to be involved in cancer-related mechanisms such as cell growth, differentiation, and cell death. Several micro, long non-coding and circular RNAs have been reported to date which are involved in PDAC. Aim of this review is to discuss the roles and functions of non-coding RNAs in diagnosis and treatments of PDAC.

LncRNA LOC146880 promotes esophageal squamous cell carcinoma progression via miR-328-5p/FSCN1/MAPK axis

We investigated the role of long non-coding RNA (lncRNA) LOC146880 in esophageal squamous cell carcinoma (ESCC). LOC146880 was significantly upregulated in ESCC tissues (n = 21) and cell lines compared to the corresponding controls. Higher LOC146880 expression correlated with poorer overall survival (OS) of ESCC patients. Moreover, CREB-binding protein (CBP) and H3K27 acetylation levels were significantly higher in the LOC146880 promoter in ESCC cell lines than in the controls. LOC146880 silencing inhibited in vitro proliferation, invasion, migration, and epithelial-mesenchymal transition of ESCC cells. LOC146880 silencing also induced G1-phase cell cycle arrest and apoptosis in ESCC cells. Bioinformatics analysis, dual luciferase reporter assays, and RNA immunoprecipitation assays showed that LOC146880 regulates FSCN1 expression in ESCC cells by sponging miR-328-5p. Moreover, FSCN1 expression correlated with activation of the MAPK signaling pathway in ESCC cells and tissues. In vivo xenograft tumor volume and liver metastasis were significantly reduced in nude mice injected with LOC146880-silenced ESCC cells as compared to those injected with control shRNA-transfected ESCC cells. These findings show that the LOC146880/miR-328-5p/FSCN1/MAPK axis regulates ESCC progression in vitro and in vivo. LOC146880 is thus a promising prognostic biomarker and potential therapeutic target in ESCC.

Long non-coding RNA TDRG1 facilitates cell proliferation, migration and invasion in breast cancer via targeting miR-214-5p/CLIC4 axis

Accumulated studies have revealed the critical role of long non-coding RNAs (lncRNAs) in the carcinogenesis and progression of various cancers. LncRNA TDRG1 has been reported to exhibit oncogenic potential in some cancers. However, its underlying mechanism regulating breast cancer (BC) remains obscure. QRT-PCR was used to measure the relative expression of mRNAs, and western blot was used to detect protein expression levels. CCK8 and CFSE assays were utilized to testify cell proliferation ability. Flow cytometry assay was used for cell apoptosis ability investigation. Transwell and tube formation assays were implemented to test cell migrating and invasive abilities. Relevant mechanism experiments were implemented to determine the molecular mechanism. TDRG1 was remarkably overexpressed in BC cell lines. TDRG1 knockdown suppressed cell proliferation, migration and invasion, but enhanced BC cell apoptosis. Mechanistically, TDRG1 acted as a miR-214-5p sponge to up-regulate CLIC4 expression. MiR-214-5p inhibition or CLIC4 overexpression could revive the tumor-suppressing effects induced by TDRG1 knockdown. TDRG1 promoted cell proliferation, migration, and invasion in BC, suggesting that TDRG1 could promisingly be a therapeutic target for BC.

Direct Effects of Lipopolysaccharide on Human Pancreatic Cancer Cells

OBJECTIVES

Obesity, a risk factor for pancreatic adenocarcinoma (PDAC), is often accompanied by a systemic increase in lipopolysaccharide (LPS; metabolic endotoxemia), which is thought to mediate obesity-associated inflammation. However, the direct effects of LPS on PDAC cells are poorly understood.

METHODS

The expression of toll-like receptor 4, the receptor for LPS, was confirmed in PDAC cell lines. AsPC-1 and PANC-1 cells were exposed to LPS, and differential gene expression was determined by RNA sequencing. The activation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway by LPS in PDAC cells was assessed by Western blotting.

RESULTS

The expression of toll-like receptor 4 was confirmed in all PDAC cell lines. The exposure to LPS led to differential expression of 3083 genes (426 ≥5-fold) in AsPC-1 and 2584 genes (339 ≥5-fold) in PANC-1. A top canonical pathway affected by LPS in both cell lines was PI3K/Akt/mTOR. Western blotting confirmed activation of this pathway as measured by phosphorylation of the ribosomal protein S6 and Akt.

CONCLUSIONS

The exposure of PDAC cells to LPS led to differential gene expression. A top canonical pathway was PI3K/Akt/mTOR, a known oncogenic driver. Our findings provided evidence that LPS can directly induce differential gene expression in PDAC cells.

Identification of MYLIP gene and miRNA-802 involved in the growth and metastasis of cervical cancer cells

BACKGROUND

The dysregulation of microRNA-802 (miR-802) has crucial roles in cancer progression. Nevertheless, the bio-function of miR-802 in cervical cancer remains unclear.

OBJECTIVE

Hence, we illuminated the potential roles of miR-802 in cervical cancer cell growth, migration, and invasion.

METHODS

The levels of miR-802 and myosin regulatory light chain interacting protein (MYLIP) were measured using qRT-PCR assay. The potential effects of miRNA-802 on cervical cancer cell proliferation and metastatic phenotypes were determined using CCK-8, colony formation, wound healing and Transwell invasion assays. MYLIP was validated as a downstream target gene of miRNA-802 using bioinformatics analysis tool and luciferase report gene assay. The impact of miR-802 on the growth of cervical cancer cell in vivo was analyzed using xenograft model. The expression of MYLIP was measured by western blotting and immunohistochemistry (IHC).

RESULTS

MiRNA-802 was distinctly down-regulated in cervical cancer cells as well as clinical cervical cancer samples. Upregulation of miRNA-802 significantly inhibited the growth and aggressiveness of cervical cancer cell. Additional, MYLIP was a functional target of miR-802. MYLIP was ovrerexpressed in cervical cancer and MYLIP level was negatively associated with the level of miR-802. Overexpression of MYLIP eliminated the inhibitory effects of miR-802 on growth and metastatic-related traits of cervical cancer cell. In vivo, miR-802 also markedly reduced the tumor growth of cervical cancer cell and decreased the expression of MYLIP.

CONCLUSIONS

MiR-802 inhibits the growth and metastatic-related phenotypes of cervical cancer cell through targeting MYLIP.

LINC00958 promotes the proliferation of TSCC via miR-211-5p/CENPK axis and activating the JAK/STAT3 signaling pathway

Background

Tongue squamous cell carcinoma (TSCC) is one of the most common oral tumors. Recently, long intergenic noncoding RNA 00958 (LINC00958) has been identified as an oncogene in human cancers. Nevertheless, the role of LINC00958 and its downstream mechanisms in TSCC is still unknown.

Methods

The effect of LINC00958 on TSCC cells proliferation and growth were assessed by CCK-8, colony formation, 5-Ethynyl-2′-deoxyuridline (EdU) assay and flow cytometry assays in vitro and tumor xenograft model in vivo. Bioinformatics analysis was used to predict the target of LINC00958 in TSCC, which was verified by RNA immunoprecipitation and luciferase reporter assays.

Results

LINC00958 was increased in TSCC tissues, and patients with high LINC00958 expression had a shorter overall survival. LINC00958 knockdown significantly decreased the growth rate of TSCC cells both in vitro and in vivo. In mechanism, LINC00958 acted as a ceRNA by competitively sponging miR-211-5p. In addition, we identified CENPK as a direct target gene of miR-211-5p, which was higher in TSCC tissues than that in adjacent normal tissues. Up-regulated miR-211-5p or down-regulated CENPK could abolish LINC00958-induced proliferation promotion in TSCC cells. Furthermore, The overexpression of CENPK promoted the expression of oncogenic cell cycle regulators and activated the JAK/STAT3 signaling.

Conclusions

Our findings suggested that LINC00958 is a potential prognostic biomarker in TSCC.

Alternative splicing of lncRNAs in human diseases

Alternative splicing (AS), a vital post-transcription process for eukaryote gene expression regulating, can efficiently improve gene utilization and increase the variety of RNA transcripts and proteins. However, AS of non-coding RNAs (ncRNAs) has not been paid enough attention to compared with that of protein-coding RNAs (mRNAs) for a long time. In fact, AS of ncRNAs, especially long noncoding RNAs (lncRNAs), also plays a significant regulatory role in the human disease. Recently, some bifunctional genes transcribed into both mRNA and lncRNA transcripts by AS have been observed. Here, we focus on the AS of lncRNAs and bifunctional genes producing lncRNA transcripts and propose a strategy for the future research of lncRNA AS.

Long non-coding RNA CERS6-AS1 facilitates the oncogenicity of pancreatic ductal adenocarcinoma by regulating the microRNA-15a-5p/FGFR1 axis

The long non-coding RNA CERS6 antisense RNA 1 (CERS6-AS1) has critical regulatory roles in breast cancer progression. Here, we determined CERS6-AS1 expression in pancreatic ductal adenocarcinoma (PDAC) and the roles of CERS6-AS1 in PDAC carcinogenesis. The mechanisms underlying the regulatory actions of CERS6-AS1 in PDAC cells were elucidated in detail. CERS6-AS1 expression was evidently increased in PDAC tissues and cell lines. Patients with PDAC having high CERS6-AS1 expression had shorter overall survival periods than those having low CERS6-AS1 expression. Functionally, the knockdown of CERS6-AS1 attenuated the proliferation, migration, and invasion and stimulated apoptosis of PDAC cells in vitro. Additionally, CERS6-AS1 depletion decreased PDAC tumor growth in vivo. Mechanistically, CERS6-AS1 could competitively bind to microRNA-15a-5p (miR-15a-5p) and effectively work as a molecular sponge in PDAC cells, resulting in the upregulation of fibroblast growth factor receptor 1 (FGFR1), a direct target of miR-15a-5p. Rescue experiments revealed that miR-15a-5p downregulation or FGFR1 restoration rescued the effects of CERS6-AS1 knockdown on the behaviors of PDAC cells. In conclusion, CERS6-AS1 promoted the oncogenicity of PDAC by serving as a competing endogenous RNA to sequester miR-15a-5p and increase FGFR1 expression, which highlights the potential of the CERS6-AS1/miR-15a-5p/FGFR1 pathway as an effective target for cancer therapy.

Identification of Circulating Serum miRNAs as Novel Biomarkers in Pancreatic Cancer Using a Penalized Algorithm

Pancreatic cancer (PC) is difficult to detect in the early stages; thus, identifying specific and sensitive biomarkers for PC diagnosis is crucial, especially in the case of early-stage tumors. Circulating microRNAs are promising non-invasive biomarkers. Therefore, we aimed to identify non-invasive miRNA biomarkers and build a model for PC diagnosis. For the training model, blood serum samples from 63 PC patients and 63 control subjects were used. We selected 39 miRNA markers using a smoothly clipped absolute deviation-based penalized support vector machine and built a PC diagnosis model. From the double cross-validation, the average test AUC was 0.98. We validated the diagnosis model using independent samples from 25 PC patients and 81 patients with intrahepatic cholangiocarcinoma (ICC) and compared the results with those obtained from the diagnosis using carbohydrate antigen 19-9. For the markers miR-155-5p, miR-4284, miR-346, miR-7145-5p, miR-5100, miR-661, miR-22-3p, miR-4486, let-7b-5p, and miR-4703-5p, we conducted quantitative reverse transcription PCR using samples from 17 independent PC patients, 8 ICC patients, and 8 healthy individuals. Differential expression was observed in samples from PC patients. The diagnosis model based on the identified markers showed high sensitivity and specificity for PC detection and is potentially useful for early PC diagnosis.

Long noncoding RNA LINC00941 promotes pancreatic cancer progression by competitively binding miR-335-5p to regulate ROCK1-mediated LIMK1/Cofilin-1 signaling

An accumulation of evidence indicates that long noncoding RNAs are involved in the tumorigenesis and progression of pancreatic cancer (PC). In this study, we investigated the functions and molecular mechanism of action of LINC00941 in PC. Quantitative PCR was used to examine the expression of LINC00941 and miR-335-5p in PC tissues and cell lines, and to investigate the correlation between LINC00941 expression and clinicopathological features. Plasmid vectors or lentiviruses were used to manipulate the expression of LINC00941, miR-335-5p, and ROCK1 in PC cell lines. Gain or loss-of-function assays and mechanistic assays were employed to verify the roles of LINC00941, miR-335-5p, and ROCK1 in PC cell growth and metastasis, both in vivo and in vitro. LINC00941 and ROCK1 were found to be highly expressed in PC, while miR-335-5p exhibited low expression. High LINC00941 expression was strongly associated with larger tumor size, lymph node metastasis, and poor prognosis. Functional experiments revealed that LINC00941 silencing significantly suppressed PC cell growth, metastasis and epithelial–mesenchymal transition. LINC00941 functioned as a molecular sponge for miR-335-5p, and a competitive endogenous RNA (ceRNA) for ROCK1, promoting ROCK1 upregulation, and LIMK1/Cofilin-1 pathway activation. Our observations lead us to conclude that LINC00941 functions as an oncogene in PC progression, behaving as a ceRNA for miR-335-5p binding. LINC00941 may therefore have potential utility as a diagnostic and treatment target in this disease.

Research progress on long non-coding RNAs and their roles as potential biomarkers for diagnosis and prognosis in pancreatic cancer

Pancreatic cancer is one of the main causes of tumor-related deaths worldwide because of its low morbidity but extremely high mortality, and is therefore colloquially known as the "king of cancer." Sudden onset and lack of early diagnostic biomarkers directly contribute to the extremely high mortality rate of pancreatic cancer patients, and also make it indistinguishable from benign pancreatic diseases and precancerous pancreatic lesions. Additionally, the lack of effective prognostic biomarkers makes it difficult for clinicians to formulate precise follow-up strategies based on the postoperative characteristics of the patients, which results in missed early diagnosis of recurrent pancreatic cancer. Long non-coding RNAs (lncRNAs) can influence cell proliferation, invasion/migration, apoptosis, and even chemoresistance via regulation of various signaling pathways, leading to pro- or anti-cancer outcomes. Given the versatile effects of lncRNAs on tumor progression, using a single lncRNA or combination of several lncRNAs may be an effective method for tumor diagnosis and prognostic predictions. This review will give a comprehensive overview of the most recent research related to lncRNAs in pancreatic cancer progression, as targeted therapies, and as biomarkers for the diagnosis and prognosis of pancreatic cancer.

The implication of long non-coding RNAs in the diagnosis, pathogenesis and drug resistance of pancreatic ductal adenocarcinoma and their possible therapeutic potential

Pancreatic ductal adenocarcinoma (PDAC) is one of the lethal malignancies with the lowest median and overall survival rate among all human malignancies. The major problems with the PDAC are the late diagnosis, metastasis, and acquired resistance to chemotherapeutic agents in the clinic. Over the last decade, the long non-coding RNAs (lncRNAs) have been discovered and occupies a significantly large proportion of the human genome. Recent studies have proved that lncRNAs can play a crucial role in the majority of key cellular processes involved in the maintenance of cellular homeostasis by regulating various molecular mechanisms. The deregulation of lncRNAs has been associated with various chronic diseases including human malignancies. Several lncRNAs have tumor-specific expression making them an ideal and excellent target for designing the novel therapeutic strategies against human malignancies. We have discussed how lncRNA expression can be used for the diagnosis and prognosis of PDAC. The current review discusses the potential role and molecular mechanism of lncRNA in regulating the prominent hallmarks of cancer including abnormal growth, survival, metastasis, and drug-resistance in PDAC. Importantly, we also highlight the possible application of various therapeutic strategies including small interfering RNA, CRISPR-Cas9, antisense oligonucleotides, locked nucleic acid Gapmers, small molecules, aptamers, lncRNA promoter to target the lncRNA as a novel and viable options for treatment of PDAC.

Long noncoding RNA LINC00514 accelerates pancreatic cancer progression by acting as a ceRNA of miR-28-5p to upregulate Rap1b expression

Background

Pancreatic cancer (PC) is one of the most aggressive cancers and has an extremely poor prognosis worldwide. Long noncoding RNA (lncRNA) has been reported to be a potential prognostic biomarker in the initiation and prognosis of PC. Nevertheless, the biological functions and the detailed molecular mechanism of LINC00514 in PC remain unclear.

Methods

We measured the expression level of LINC00514 in PC tissues and cell lines by quantitative real-time PCR. Gain- and loss-of-function experiments were performed to explore the bioeffects of LINC00514 on PC development both in vitro and in vivo. Subcellular fractionation, luciferase reporter assay, RNA immunoprecipitation assay, pull-down assay and western blotting were performed to investigate the oncogenic molecular mechanisms of LINC00514.

Results

In this study, LINC00514 was shown to be upregulated in PC tissues and cell lines. Increased LINC00514 expression was significantly associated with the clinical progression and prognosis of PC patients. In addition, silencing LINC00514 inhibited PC cell proliferation, migration and invasion, while LINC00514 overexpression promoted these processes. Moreover, LINC00514 knockdown remarkably inhibited PC development and metastasis in vivo. Deeper investigations indicated that LINC00514 acted as a sponge for microRNA-28-5p (miR-28-5p) in PC and that Rap1b was a downstream target of miR-28-5p. Furthermore, the positive correlation of LINC00514 and Rap1b and the negative correlation between miR-28-5p and LINC00514 (or Rap1b) were revealed. Based on the rescue assays, Rap1b inhibition partially suppressed the oncogenic effect of LINC00514 overexpression on PC cell proliferation, migration and invasion.

Conclusions

This study is the first to characterize the oncogenic function of the long noncoding RNA LINC00514 in pancreatic cancer progression by acting as a competing endogenous RNA (ceRNA) of miR-28-5p to upregulate Rap1b expression. Understanding this molecular mechanism might contribute to further discoveries of better diagnostic and therapeutic options for pancreatic cancer.

Long noncoding RNA PVT1 promotes tumor cell proliferation, invasion, migration and inhibits apoptosis in oral squamous cell carcinoma by regulating miR‑150‑5p/GLUT‑1

Oral squamous cell carcinoma (OSCC) is a cancer with high morbidity and mortality. Research has demonstrated that long non-coding RNAs (lncRNAs) are critical for tumor initiation and development. In the present study, we aimed to ascertain the functions and potential mechanisms of lncRNA plasmacytoma variant translocation 1 (PVT1) in OSCC. Firstly, we found that the expression of PVT1 was increased in human OSCC tumor tissues and it was related to reduced survival of the patients. Furthermore, miR-150-5p expression was downregulated in OSCC tumor tissues and it was negatively related with PVT1. Moreover, GLUT-1 protein expression was upregulated in human OSCC tumor tissues. In addition, cell proliferation capacity was measured by CCK-8 assay and cell invasion and migration were measured by Transwell assay. PVT1 overexpression promoted cell proliferation, invasion and migration, while these effects were abrogated by PVT1 downregulation. In addition, luciferase gene reporter assay verified the miR-150-5p directly binds with PVT1, which regulates the biological functions of OSCC. Additionally, luciferase gene reporter assay confirmed that GLUT-1 was a target for miR-150-5p. The promotion of cell proliferation, invasion and migration in LV-PVT1-transfected cells was eliminated following miR-150-5p overexpression. Finally, in vivo nude mouse xenograft model further verified that PVT1 knockdown inhibited tumor growth, formation, invasion and migration. According to the results, PVT1 is increased in human OSCC tumor tissues, and is related to the poor prognosis of human OSCC patients. We uncovered a previously unappreciated PVT1/miR-150-5p/GLUT-1 signaling axis that promotes cell proliferation, invasion, migration and inhibits apoptosis in OSCC cell lines and in vivo, which suggests that this axis could be a target for the treatment of OSCC.

Long noncoding RNA LINC01559 promotes pancreatic cancer progression by acting as a competing endogenous RNA of miR-1343-3p to upregulate RAF1 expression

Background: An increasing number of studies have shown that lncRNAs are involved in the biological processes of pancreatic cancer (PC). Hence, we investigated the role of a novel noncoding RNA, LINC01559, involved in PC progression.

Results: LINC01559 and RAF1 were highly expressed in PC, while miR-1343-3p had low expression. High expression of LINC01559 was significantly associated with large tumors, lymph node metastasis, and poor prognosis. Functional experiment results revealed that silencing of LINC01559 significantly suppressed PC cell proliferation and metastasis. Meanwhile, LINC01559 could act as a ceRNA to competitively sponge miR-1343-3p to up-regulate RAF1 and activate its downstream ERK pathway

Conclusions: LINC01559 functions as an oncogene in PC progression through acting as a ceRNA of miR-1343-3p. Hence, LINC01559 is a potential diagnostic and therapeutic target.

Methods: RT-qPCR was performed to determine the expression of LINC01559 and miR-1343-3p in PC. Individual patient data were collected to investigate the correlation between clinicopathological features and LINC01559 expression. Subsequently, the expression of LINC01559, miR-1343-3p, and RAF1 was altered using transfection of vectors or inhibitors. Gain- and loss-of-function assays and mechanistic assays were applied to verify the effects of LINC01559, miR-1343-3p, and RAF1 on PC cell proliferation and metastasis in vivo and in vitro.

SOX9-activated PXN-AS1 promotes the tumorigenesis of glioblastoma by EZH2-mediated methylation of DKK1

Increasing evidence has validated the essential regulation of long non-coding RNAs (lncRNAs) in the biological process of tumours. LncRNA PXN-AS1 has been discovered to be as a tumour suppressor in pancreatic cancer; however, its function and mechanism remain greatly unknown in glioblastoma (GBM). Our present study indicated that PXN-AS1 was highly expressed in GBM tissues and cells. Besides, the knock-down of PXN-AS1 was closely associated with the inhibitory proliferation and inducing apoptosis of GBM cells. PXN-AS1 inhibition was also found to restrain GBM tumour growth. Importantly, SOX9 functioned as a transcription factor and activated PXN-AS1 expression, and overexpressed PXN-AS1 rescued the inhibitory role of down-regulated SOX9 in GBM cell growth. Subsequently, it was discovered that PXN-AS1 activated Wnt/β-catenin pathway. DKK1 was widely known as an inhibitor gene of Wnt/β-catenin pathway, and its expression was negatively associated with PXN-AS1 and SOX9. Interestingly, we found that PXN-AS1 could recruit EZH2 to mediate the H3K27me3 level of DKK1 promoter. Restoration experiments manifested that DKK1 knock-down counteracted PXN-AS1 depletion-mediated repression in GBM cell growth. All facts pointed out that PXN-AS1 might be of importance in exploring the therapeutic strategies of GBM.

Correction to: Long non-coding RNA PXN-AS1 suppresses pancreatic cancer progression by acting as a competing endogenous RNA of miR-3064 to upregulate PIP4K2B expression

In the original publication of this manuscript [1], there are errors in Fig. 3. The authors declare that the identified errors do not change the results or conclusions of this paper.

Downregulation of miR-486-5p Enhances the Anti-Tumor Effect of 5-Fluorouracil on Pancreatic Cancer Cells

Background

5-Fluorouracil (5-Fu) has been applied to treat pancreatic cancer, which is one of the most common types of digestive system tumors. Evidence has shown that miR-486-5p could promote the proliferation of pancreatic cancer cells. Therefore, this study aimed to investigate whether downregulation of miR-486-5p could enhance the anti-tumor effect of 5-Fu on pancreatic cancer cells.

Methods

Cell Counting Kit 8 assay, flow cytometry and wound healing assays were used to detect proliferation, apoptosis and migration in PANC-1 cells. The expressions of Bcl-2, Bax, cleaved caspase 3, PTEN, p-Akt and p-ERK in PANC-1 cells were detected with Western blot assay.

Results

In this study, the inhibitory effects of 5-Fu on the proliferation, migration and invasion of PANC-1 cells were significantly enhanced following transfection with miR-486-5p antagonist. In addition, downregulation of miR-486-5p markedly enhanced the pro-apoptosis effect of 5-Fu on PANC-1 cells. Moreover, bioinformatics analysis and luciferase reporter assay identified that PTEN was the directly binding target of miR-486-5p. Meanwhile, downregulation of miR-486-5p markedly enhanced the anti-tumor effect of 5-Fu in PANC-1 cells via upregulation of the level of PTEN, and downregulation of the expressions of p-ERK and p-Akt. In vivo experiments confirmed that knockdown of miR-486-5p could enhance the anti-tumor effect of 5-Fu in PANC-1 xenograft model.

Conclusion

We found that the downregulation of miR-486-5p could enhance the anti-tumor effect of 5-Fu on pancreatic cancer cells. Therefore, miR-486-5p antagonist plus 5-Fu might be considered as a potential therapeutic strategy for the treatment of pancreatic cancer.

miR-6089/MYH9/β-catenin/c-Jun negative feedback loop inhibits ovarian cancer carcinogenesis and progression

The pathogenesis of ovarian cancer remains to be elucidated. Our previous study demonstrated that myosin heavy chain 9 (MYH9) overexpression was associated with poor prognosis of epithelial ovarian cancer. However, the mechanism of MYH9 and its regulation by microRNA (miR) is not clear. The results of the present study demonstrated that miR-6089 was one of the microRNAs targeting MYH9, and miR-6089 overexpression suppressed ovarian cancer cell proliferation, migration, invasion and metastasis in vivo and in vitro. Mechanistic studies confirmed that miR-6089 directly targeted MYH9 to inactivate the Wnt/β-catenin signalling pathway and its downstream epithelial-to-mesenchymal transition (EMT), cell-cycle factors and c-Jun, whereas overexpression of MYH9 reversed the inhibitory effects of miR-6089 overexpression in ovarian cancer cells by upregulating the Wnt/β-catenin and its downstream EMT, cell-cycle factors and c-Jun. Interestingly, miR-6089 was transcriptionally inhibited by c-Jun, a transcription factor which could be induced by MYH9 via the Wnt/β-catenin pathway. Thus miR-6089/MYH9/β-catenin/c-Jun formed a negative feedback loop in ovarian cancer. In clinical samples, miR-6089 negatively correlated with MYH9 expression. Our study is the first to demonstrate that miR-6089 serves as a tumor-suppressive miRNA, and miR-6089/MYH9/β-catenin/c-Jun negative feedback loop inhibits ovarian cancer carcinogenesis and progression.

Long Noncoding RNA ZFPM2-AS1 Enhances the Malignancy of Cervical Cancer by Functioning as a Molecular Sponge of microRNA-511-3p and Consequently Increasing FGFR2 Expression

Purpose

A long noncoding RNA called ZFPM2 antisense RNA 1 (ZFPM2-AS1) has been verified as a key modulator in multiple human cancer types. Nonetheless, the expression and functions of ZFPM2-AS1 in cervical cancer remain poorly understood. Therefore, our purpose was to characterize the expression pattern, clinical value, and detailed roles of ZFPM2-AS1 in cervical cancer.

Methods

Reverse-transcription quantitative PCR was carried out to measure ZFPM2-AS1 expression in cervical cancer. A Cell Counting Kit-8 assay, flow cytometry, Transwell migration and invasion assays, and a tumor xenograft experiment were conducted to determine the influence of ZFPM2-AS1 on cervical cancer cell proliferation, apoptosis, migration, and invasion in vitro and on tumor growth in vivo, respectively.

Results

ZFPM2-AS1 was found to be aberrantly upregulated in cervical cancer, and its upregulation was associated with unfavorable values of clinical parameters. A ZFPM2-AS1 knockdown significantly reduced cervical cancer cell proliferation, migration, and invasion and increased apoptosis in vitro. The ZFPM2-AS1 knockdown decelerated tumor growth of cervical cancer cells in vivo. Molecular investigation indicated that ZFPM2-AS1 acts as a molecular sponge of microRNA-511-3p (miR-511-3p) in cervical cancer cells. Fibroblast growth factor receptor 2 (FGFR2) mRNA was validated as a direct target of miR-511-3p in cervical cancer, and its expression was positively modulated by ZFPM2-AS1. The effects of the ZFPM2-AS1 knockdown on malignant characteristics of cervical cancer cells were greatly attenuated by miR-511-3p inhibition.

Conclusion

ZFPM2-AS1 promotes cervical cancer progression through upregulation of miR-511-3p–FGFR2 axis output, thereby pointing to possible diagnostics and therapeutics based on the ZFPM2-AS1–miR-511-3p–FGFR2 pathway.

LncRNA-ATB Promotes the Tumorigenesis of Ovarian Cancer via Targeting miR-204-3p

Background

Ovarian cancer ranks fifth among the most prevalent cancer type in females all over the world. It is the second most frequent malignant tumor which accounts for 3% of cancer in females. Therefore, to explore the mechanism of carcinogenesis in ovarian cancer is important to develop new treatment methods. It has been previously found that lncRNA-ATB could promote the tumorigenesis of malignant tumors. However, the role of lncRNA-ATB during the progression of ovarian cancer remains unclear.

Methods

Gene expressions in tissues or cells were detected by using qRT-PCR. Western blot was performed to investigate the protein expressions in ovarian cancer cells. Cell apoptosis was tested by flow cytometry. Moreover, the correction between lncRNA-ATB and miR-204-3p was examined by Dual-luciferase reporter assay and RNA pulldown. Cell proliferation and invasion were detected by CCK-8, Ki-67 staining and transwell assay, respectively. Finally, xenograft mice model was established to confirm the result of in vitro experiments.

Results

LncRNA-ATB silencing significantly inhibited the proliferation and induced apoptosis of ovarian cancer cells. In addition, luciferase activity suggested that lncRNA-ATB negatively regulated miR-204-3p in ovarian cancer. Besides, Nidogen 1 (NID1) was the direct target of miR-204-3p. Overexpression of NID1 could notably reverse the inhibitory effect of lncRNA-ATB knockdown on the progression of ovarian cancer. Finally, lncRNA-ATB silencing notably attenuated the severity of ovarian cancer in vivo.

Conclusion

Downregulation of lncRNA-ATB significantly inhibited the tumorigenesis of ovarian cancer in vitro and in vivo, which may serve as a potential novel target for the treatment of ovarian cancer.

LncRNA NEAT1 facilitates pancreatic cancer growth and metastasis through stabilizing ELF3 mRNA

Recently, increasing evidence has revealed that long noncoding RNAs (lncRNAs) play important roles in the pathogenesis of multiple cancers. Although the oncogenic effects of lncRNA nuclear-enriched abundant transcript 1 (NEAT1) in some cancers have been reported, the functional significance and molecular mechanism of NEAT1 in pancreatic cancer (PC) progression remains elusive. In this study, our findings showed that NEAT1 expression was upregulated in PC tissues and cell lines; high NEAT1 expression was associated with tumor size, TNM stage, lymph node and distant metastasis, and also predicted poor prognosis. Functional experiments demonstrated that NEAT1 could promote PC cell proliferation and metastasis both in vitro and in vivo. Mechanistically, NEAT1 could associate with E74 like ETS transcription factor 3 (ELF3) mRNA and enhance the combination of Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) and ELF3 mRNA, subsequently suppressing the degradation of ELF3 mRNA. Overall, our research indicates that NEAT1 might be a potential therapeutic target for patients with PC.