Micro-RNAs miR-29a and miR-330-5p function as tumor suppressors by targeting the MUC1 mucin in pancreatic cancer cells

Discovery of novel microRNA mimic repressors of ribosome biogenesis

While microRNAs and other non-coding RNAs are the next frontier of novel regulators of mammalian ribosome biogenesis (RB), a systematic exploration of microRNA-mediated RB regulation has not yet been undertaken. We carried out a high-content screen in MCF10A cells for changes in nucleolar number using a library of 2603 mature human microRNA mimics. Following a secondary screen for nucleolar rRNA biogenesis inhibition, we identified 72 novel microRNA negative regulators of RB after stringent hit calling. Hits included 27 well-conserved microRNAs present in MirGeneDB, and were enriched for mRNA targets encoding proteins with nucleolar localization or functions in cell cycle regulation. Rigorous selection and validation of a subset of 15 microRNA hits unexpectedly revealed that most of them caused dysregulated pre-rRNA processing, elucidating a novel role for microRNAs in RB regulation. Almost all hits impaired global protein synthesis and upregulated CDKN1A (p21) levels, while causing diverse effects on RNA Polymerase 1 (RNAP1) transcription and TP53 protein levels. We provide evidence that the MIR-28 siblings, hsa-miR-28-5p and hsa-miR-708-5p, potently target the ribosomal protein mRNA RPS28 via tandem primate-specific 3' UTR binding sites, causing a severe pre-18S pre-rRNA processing defect. Our work illuminates novel microRNA attenuators of RB, forging a promising new path for microRNA mimic chemotherapeutics.

Advances in MUC1 resistance to chemotherapy in pancreatic cancer

The incidence of pancreatic cancer (PC), a highly fatal malignancy, is increasing every year. Chemotherapy is an important treatment for it in addition to surgery, yet most patients become resistant to chemotherapeutic agents within a few weeks of treatment initiation.​ MUC1 is a highly glycosylated transmembrane protein, and studies have shown that aberrantly glycosylated overexpression of MUC1 is involved in regulating the biology of chemoresistance in cancer cells. This article summarizes the mechanism of MUC1 in PC chemoresistance and reviews MUC1-based targeted therapies.

Discovery of novel microRNA mimic repressors of ribosome biogenesis

While microRNAs and other non-coding RNAs are the next frontier of novel regulators of mammalian ribosome biogenesis (RB), a systematic exploration of microRNA-mediated RB regulation has not yet been undertaken. We carried out a high-content screen in MCF10A cells for changes in nucleolar number using a library of 2,603 mature human microRNA mimics. Following a secondary screen for nucleolar rRNA biogenesis inhibition, we identified 72 novel microRNA negative regulators of RB after stringent hit calling. Hits included 27 well-conserved microRNAs present in MirGeneDB, and were enriched for mRNA targets encoding proteins with nucleolar localization or functions in cell cycle regulation. Rigorous selection and validation of a subset of 15 microRNA hits unexpectedly revealed that most of them caused dysregulated pre-rRNA processing, elucidating a novel role for microRNAs in RB regulation. Almost all hits impaired global protein synthesis and upregulated CDKN1A ( p21 ) levels, while causing diverse effects on RNA Polymerase 1 (RNAP1) transcription and TP53 protein levels. We discovered that the MIR-28 siblings, hsa-miR-28-5p and hsa-miR-708-5p, directly and potently target the ribosomal protein mRNA RPS28 via tandem primate-specific 3' UTR binding sites, causing a severe pre-18S pre-rRNA processing defect. Our work illuminates novel microRNA attenuators of RB, forging a promising new path for microRNA mimic chemotherapeutics.

The influence of selected microRNAs on the expression profile of genes and proteins related to the tumor necrosis factor-alpha signaling pathways in endometrioid endometrial cancer

PURPOSE

Tumor necrosis factor exerts many adverse biological effects, from cell proliferation to cell death. Accurate diagnosis and treatment are therefore difficult due to many factors influencing tumor necrosis factor-alpha (TNF-α) signaling, including microRNAs (miRNAs), especially in tumors. The aim of the study was to determine the influence of miRNAs on the expression profile of genes and proteins related to TNF-α signaling in endometrial cancer.

METHODS

The material consisted of 45 endometrioid endometrial cancer and 45 normal endometrium tissue samples. Gene expression was determined with microarrays and then validated for TNF-α, tumor necrosis factor receptor 1 (TNFR1) and 2 (TNFR2), caveolin 1 (CAV1), nuclear factor kappa B subunit 1 (NFKB1), and TGF-beta activated kinase 1 (MAP3K7)-binding protein 2 (TAB2) using real-time quantitative reverse transcription reaction (RT-qPCR). The protein concentration was assessed by enzyme-linked immunosorbent assay (ELISA). In addition, differentiating miRNAs were identified using miRNA microarrays and their relationships with TNF-α signaling genes were evaluated using the mirDIP tool.

RESULTS

TNF-α, TNFR1, TNFR2, CAV1, NFKB1, and TAB2 were upregulated both on the mRNA and protein levels. The decrease in the activity of miR-1207-5p, miR-1910-3p, and miR-940 may be related to CAV1 overexpression. Similarly for miR-572 and NFKB1 as well as miR-939-5p and TNF-α. In turn, miR-3178 may partially inhibit TNFR1 activity up to grade 2 cancer.

CONCLUSION

TNF-α signaling, especially the TNF-α/NF-κB axis, is disrupted in endometrial cancer and worsens with disease progression. The observed changes may be the result of miRNAs' activity in the initial stage of endometrial cancer and its gradual loss in later grades.

The multifaceted role of MUC1 in tumor therapy resistance

Tumor therapeutic resistances are frequently linked to the recurrence and poor prognosis of cancers and have been a key bottleneck in clinical tumor treatment. Mucin1 (MUC1), a heterodimeric transmembrane glycoprotein, exhibits abnormally overexpression in a variety of human tumors and has been confirmed to be related to the formation of therapeutic resistance. In this review, the multifaceted roles of MUC1 in tumor therapy resistance are summarized from aspects of pan-cancer principles shared among therapies and individual mechanisms dependent on different therapies. Concretely, the common mechanisms of therapy resistance across cancers include interfering with gene expression, promoting genome instability, modifying tumor microenvironment, enhancing cancer heterogeneity and stemness, and activating evasion and metastasis. Moreover, the individual mechanisms of therapy resistance in chemotherapy, radiotherapy, and biotherapy are introduced. Last but not least, MUC1-involved therapy resistance in different types of cancers and MUC1-related clinical trials are summarized.

Hsa_circ_0040809 and hsa_circ_0000467 promote colorectal cancer cells progression and construction of a circRNA-miRNA-mRNA network

Objective: Circular RNAs (circRNAs) have been demonstrated to be closely involved in colorectal cancer (CRC) pathogenesis and metastasis. More potential biomarkers are needed to be searched for colorectal cancer (CRC) diagnosis and treatment. The objective of this study is to seek differentially expressed circRNAs (DEcircRNAs), test their roles in CRC and construct a potential competing endogenous RNA (ceRNA) network.

Methods: CircRNA microarrays were obtained from Gene Expression Omnibus, and differential expression was analyzed by R software. The relative expressions of DEcircRNAs were confirmed in CRC tissues and cell lines by qRT-PCR. MTs and Transwell experiments were performed for detecting the roles of circRNAs on CRC cell proliferation and migration, respectively. Targeted miRNAs of circRNAs and targeted mRNAs of miRNAs were predicted and screened by bioinformatics methods. A ceRNA network of DEcircRNAs was constructed by Cytoscape. To further verify the potential ceRNA network, the expressions of miRNAs and mRNAs in knockdown of DEcircRNAs CRC cells were detected by qRT-PCR.

Results: Two DEcircRNAs (hsa_circ_0040809 and hsa_circ_0000467) were identified and validated in CRC tissues and cell lines. The results of MTs and Transwell experiments showed that hsa_circ_0040809 and hsa_circ_0000467 promoted CRC proliferation and migration. Bioinformatics analysis screened 3 miRNAs (miR-326, miR-330-5p, and miR-330-3p) and 2 mRNAs (FADS1 and RUNX1), and a ceRNA network was constructed. In knockdown of hsa_circ_0040809 HCT-116 cells, the expression of miR-330-3p was significantly upregulated, while RUNX1 was significantly downregulated. In knockdown of hsa_circ_0000467 HCT-116 cells, the expressions of miR-326 and miR-330-3p were upregulated, while FADS1was downregulated.

Conclusion: We found that hsa_circ_0040809 and hsa_circ_0000467 were upregulated in CRC tissues and cell lines, and promoted CRC cell progression. A circRNA-miRNA-mRNA network based on hsa_circ_0040809 and hsa_circ_0000467 was constructed.

An Exosomal miRNA Biomarker for the Detection of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains a difficult tumor to diagnose and treat. To date, PDAC lacks routine screening with no markers available for early detection. Exosomes are 40-150 nm-sized extracellular vesicles that contain DNA, RNA, and proteins. These exosomes are released by all cell types into circulation and thus can be harvested from patient body fluids, thereby facilitating a non-invasive method for PDAC detection. A bioinformatics analysis was conducted utilizing publicly available miRNA pancreatic cancer expression and genome databases. Through this analysis, we identified 18 miRNA with strong potential for PDAC detection. From this analysis, 10 (MIR31, MIR93, MIR133A1, MIR210, MIR330, MIR339, MIR425, MIR429, MIR1208, and MIR3620) were chosen due to high copy number variation as well as their potential to differentiate patients with chronic pancreatitis, neoplasms, and PDAC. These 10 were examined for their mature miRNA expression patterns, giving rise to 18 mature miRs for further analysis. Exosomal RNA from cell culture media was analyzed via RTqPCR and seven mature miRs exhibited statistical significance (miR-31-5p, miR-31-3p, miR-210-3p, miR-339-5p, miR-425-5p, miR-425-3p, and miR-429). These identified biomarkers can potentially be used for early detection of PDAC.

Roles of Antimicrobial Peptides in Gynecological Cancers

Antimicrobial peptides (AMPs) are essential components of the mucosal barrier of the female reproductive tract (FRT) and are involved in many important physiological processes, including shaping the microbiota and maintaining normal reproduction and pregnancy. Gynecological cancers seriously threaten women's health and bring a heavy burden to society so that new strategies are needed to deal with these diseases. Recent studies have suggested that AMPs also have a complex yet intriguing relationship with gynecological cancers. The expression level of AMPs changes during tumor progression and they may act as promising biomarkers in cancer detection and prognosis prediction. Although AMPs have long been considered as host protective, they actually play a "double-edged sword" role in gynecological cancers, either tumorigenic or antitumor, depending on factors such as AMP and cancer types, as well as AMP concentrations. Moreover, AMPs are associated with chemoresistance and regulation of AMPs' expression may alter sensitivity of cancer cells to chemotherapy. However, more work is needed, especially on the identification of molecular mechanisms of AMPs in the FRT, as well as the clinical application of these AMPs in detection, diagnosis and treatment of gynecological malignancies.

The Role of miR-29s in Human Cancers—An Update

MicroRNAs (miRNAs) are small non-coding RNAs that directly bind to the 3’ untranslated region (3’-UTR) of the target mRNAs to inhibit their expression. The miRNA-29s (miR-29s) are suggested to be either tumor suppressors or oncogenic miRNAs that are strongly dysregulated in various types of cancer. Their dysregulation alters the expression of their target genes, thereby exerting influence on different cellular pathways including cell proliferation, apoptosis, migration, and invasion, thereby contributing to carcinogenesis. In the present review, we aimed to provide an overview of the current knowledge on the miR-29s biological network and its functions in cancer, as well as its current and potential applications as a diagnostic and prognostic biomarker and/or a therapeutic target in major types of human cancer.

Clinical role of MiRNA 29a and MiRNA 335 on breast cancer management: their relevance to MMP2 protein level

BACKGROUND

Circulating miRNAs are novel biomarkers, authors aimed to investigate the expression level of miR-29a and miR-335 and their relevance to CEA, CA15.3, and matrix metalloproteinase-2 (MMP2).

MATERIALS AND METHODS

Breast cancer (BC) patients (n = 44), benign breast lesion patients (n = 25), and healthy individuals (n = 19) were enrolled for detection of miRNA expression levels, MMP2 and biochemical markers using quantitative polymerase chain reaction (PCR) and ELISA, respectively.

RESULTS

Expression of miR-29a and miR-335 were significantly decreased in breast patients as compared to healthy individuals, while biochemical markers were high in BC patients as compared to the other two groups. The diagnostic efficacy for miR-29a, miR-335, and MMP2 were superior to both CEA and CA 15.3 for early detection of BC patients.

CONCLUSIONS

Detection of the miR-29a and miR335 expression levels in serum samples are significant promising biomarkers for BC diagnosis.

Exosome circRNAs and ceRNA network profiles in different ANA sera

Increasing evidences show that circRNAs are associated with some autoimmunity diseases either as a biomarker or therapeutic target. Exosomes containing nucleic acids and proteins are found in sera of series diseases and could serve as either diagnostic or therapeutic target. ANA serves as first common diagnostic test for autoimmunity disease, different ANA staining reflecting different types of autoimmunity disease. Till now, whether different ANA sera exosomes express different circRNAs and relevant ceRNA networks are still shortage of investigation. This study analyzed circRNAs, miRNAs, and their interaction networks in different ANA sera exosomes by high-throughput sequencing. It found no significant difference of total circRNAs and miRNAs amount across different ANA sera exosomes. However, significant differences were found of circRNAs, miRNA constituents, function analysis by KEGG and GO, and their ceRNA networks including miRNA-circRNA and miRNA-mRNA among different ANA sera exosomes, suggesting sera exosome circRNAs as either biomarker or mechanism of autoimmunity diseases.

Expression of specific microRNAs in tissue and plasma in colorectal cancer

BACKGROUND

MicroRNAs (miRNA/miR) play significant roles in the regulation of cell differentiation, cell cycle progression, and apoptosis. They become dysregulated during carcinogenesis and are eventually released into the circulation, enabling their detection in body fluids. Thus, this study compared the miRNA expression in tissue and plasma samples of colorectal cancer (CRC) patients and clinically healthy controls and determined miRNA expression as a potential CRC biomarker.

METHODS

Using quantitative reverse transcription polymerase chain reaction (RT-qPCR), miR-21-5p, miR-29a-3p, miR-92a-3p, miR-135b-5p, miR-196b-5p, and miR-197-3p, expression was analyzed and compared between the malignant (n = 41) and the adjacent neoplasm free mucosal tissues (n = 41) of CRC patients. The findings were validated in plasma samples (n = 36) collected from the same CRC patients prior to surgery or any form of treatment and compared to plasma from their age and sex-matched controls (n = 36).

RESULTS

MiR-21-5p, miR-29a-3p, miR-92a-3p, and miR- 196b-5p were upregulated and miR-135b-5p was downregulated in CRC malignant tissues compared to their expression in adjacent neoplasm-free tissue. This was further observed in the plasma of the same CRC cases compared to controls. MiR-92a-3p showed itself the most sensitive (0.93; p < .001) and most specific (0.95; p < .001) in detecting CRC in tissue. In plasma, miR-196b-5p was the most sensitive (0.97; p < .001) and specific (0.94; p < .001) in detecting CRC. Plasma miR-92a-3p and miR-196b-5p were the most sensitive (0.95; p < .001) and specific (0.94; p < .001) in the early detection of CRC.

CONCLUSIONS

Results show that specific miRNAs dysregulated in malignant tissues are released and can be detected in the circulation, supporting their potential as non-invasive biomarkers of CRC.

Pancreatic cancer and oligonucleotide therapy: Exploring novel therapeutic options and targeting chemoresistance

Pancreatic cancer (PC) represents a malignancy with increased mortality rate, as less than 10% of patients survive for 5 years after diagnosis. Current evolution in basic sciences has revealed promising results by decrypting genetic loci vulnerable to mutations, as potential targets of novel treatment choices. In this regard, the "Oligonucleotide therapeutics", based on synthetic nucleotides, modify the function and expression of their targets. Antisense oligonucleotides (ASOs), small interfering RNA (siRNA), microRNAs (miRNAs), aptamers, CpG oligodeoxynucleotides and decoys comprise the main representatives of this emerging technology, by regulating oncogenes' expression, restoring DNA repairment mechanisms, sensitizing cancer cells in chemotherapy, and inhibiting PC progress. A plethora of genetic treatment molecules and respective targets have been described and are currently studied, thus providing a broad range of probable pharmaceutical options. This narrative review illuminates the main parameters of genetic treatment molecules for PC and underlines their deficiencies, to clarify the upcoming future and trigger further investigation in PC management.

Senescence-Associated miRNAs and Their Role in Pancreatic Cancer

Replicative senescence is irreversible cell proliferation arrest for somatic cells which can be circumvented in cancers. Cellular senescence is a process, which may play two opposite roles. On the one hand, this is a natural protection of somatic cells against unlimited proliferation and malignant transformation. On the other hand, cellular secretion caused by senescence can stimulate inflammation and proliferation of adjacent cells that may promote malignancy. The main genes controlling the senescence pathways are also well known as tumor suppressors. Almost 140 genes regulate both cellular senescence and cancer pathways. About two thirds of these genes (64%) are regulated by microRNAs. Senescence-associated miRNAs can stimulate cancer progression or act as tumor suppressors. Here we review the role playing by senescence-associated miRNAs in development, diagnostics and treatment of pancreatic cancer.

LncRNA BIRF Promotes Brain Ischemic Tolerance Induced By Cerebral Ischemic Preconditioning Through Upregulating GLT-1 via Sponging miR-330-5p

Long noncoding RNAs (lncRNAs) play an important regulatory role in various diseases. However, the role of lncRNAs in brain ischemic tolerance (BIT) induced by cerebral ischemic preconditioning (CIPC) is still unknown. The lncRNA profile of rat cortical astrocytes pretreated with ischemic preconditioning was analyzed by high-throughput sequencing. The results of Cell-Counting Kit-8 (CCK-8) assay showed that a novel lncRNA, NONRATT009133.2, which we referred to as brain ischemia-related factor (BIRF), was highly correlated with BIT. Through bioinformatics analysis, we predicted that BIRF, miR-330-5p, and GLT-1 (also named Slc1a2) might constitute a ceRNA regulatory network in the induction of BIT. We found that BIRF was upregulated by CIPC, which promoted GLT-1 expression and BIT induction. BIRF could directly bind to miR-330-5p. Furthermore, miR-330-5p directly targeted GLT-1, and miR-330-5p inhibited both GLT-1 expression and BIT induction in vitro and in vivo. Moreover, BIRF acts as a molecular sponge to competitively bind to miR-330-5p with GLT-1 mRNA, while the miR-330-5p inhibitor reversed all the effects of BIRF siRNA on GLT-1 expression and neuronal vitality. Taken together, our results demonstrate the important roles of the BIRF/miR-330-5p/GLT-1 axis in the induction of BIT by CIPC. BIRF may be a potentially effective therapeutic strategy against stroke injury.

The circular RNA circFARSA sponges microRNA-330-5p in tumor cells with bladder cancer phenotype

Background

Circular RNAs (circRNAs) modulate gene expression in various malignancies. However, their roles in the occurrence of bladder cancer (BC) and their underlying mechanisms of action are currently unclear.

Methods

We measured levels of the circRNA phenylalanyl-tRNA synthetase subunit alpha (circFARSA) and target microRNAs (miRNAs/miRs) in BC tissues and cell lines using quantitative polymerase chain reactions. The functions of circFARSA in tumor formation were examined in mice with BC xenografts in vivo and in BC cells via determination of their proliferation, activity, apoptosis, metastasis, and invasion in vitro using cell counting kit-8 assays, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, flow cytometry, western blotting, Transwell assays, and cell wound healing assays. Interactions between miR-330 and circFARSA were predicted and confirmed by bioinformatic processing and dual-luciferase reporter gene assays, respectively. Expression profiles of miR-330 targets in BC cells were assessed via western blotting.

Results

circFARSA expression was markedly upregulated in BC tissues and cell lines compared with that in normal bladder samples. Silencing circFARSA expression decreased BC cell proliferation, invasion, and migration but induced their apoptosis in vitro. Downregulating circFARSA expression slowed tumor growth in vivo and directly sponged miR-330 and inhibited its function in BC cells in vitro. Inhibiting miR-330 expression abolished the regulatory effects of circFARSA silencing on the tumor phenotypes of BC cells.

Conclusions

circFARSA expression is upregulated and exerts oncogenic functions in BC by sponging miR-330.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09467-7.

LINC00483 promotes proliferation and metastasis through the miR-19a-3p/TBK1/MAPK axis in pancreatic ductal adenocarcinoma (PDAC)

Background

Long noncoding RNAs (lncRNAs) have been found to promote tumor progression. However, the role of lncRNAs in pancreatic ductal adenocarcinoma (PDAC) requires more investigation.

Methods

In this study, microarray was used to measure lncRNA levels in 3 pairs of PDAC tissues. As the highest upregulated lncRNA, LINC00483 was selected for further investigation to determine its functions in PDAC. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to confirm LINC00483 level in PDAC. PDAC cell lines were transfected with short hairpin RNA (shRNA) or microRNA (miRNA). 5-ethynyl-2'-deoxyuridine (EdU) assay, colony formation assay, wound healing assay, transwell assay, and xenograft mouse models were used to evaluate LINC00483 inhibition in vitro and in vivo. Luciferase reporter assay was performed to confirm binding sites of LINC00483 with miR-19a-3p, and miR-19a-3p with TANK-binding kinase 1 (TBK1). Immunohistochemistry (IHC) was performed to evaluate TBK1 and c-myc expression in PDAC tissues. Western blot was used to elucidate the LINC00483/miR-19a-3p/TBK1/mitogen-activated protein kinase (MAPK) axis.

Results

Our data showed that LINC00483 was significantly upregulated in PDAC compared to normal tissue. High level of LINC00483 was correlated with advanced clinical stage, tumor invasion and metastasis, and adverse prognosis in PDAC patients. LINC00483 suppression inhibited proliferation and invasion in vitro and tumor development in vivo via modulation of miR-19a-3p expression. Subsequently, we found that miR-19a-3p binds to TBK1 in PDAC and LINC00483 could regulate PDAC cell progression by regulating miR-19a-3p via the TBK1/MAPK pathway.

Conclusions

The results of our study suggested that the LINC00483/miR-19a-3p/TBK1/MAPK axis contributed to PDAC progression, which provides a potential therapeutic target for PDAC treatment.

Dysregulated expression and functions of microRNA-330 in cancers: A potential therapeutic target

As small non-coding RNAs, MicroRNAs (miRNAs) bind to the 3' untranslated region (3'-UTR) of mRNA targets to control gene transcription and translation. The gene of miR-330 has two miRNA products, including miR-330-3p and miR-330-5p, which exhibit anti-tumorigenesis and/or pro-tumorigenesis effects in many kinds of malignancies. In cancers, miR-330-3p and miR-330-5p aberrant expression can influence many malignancy-related processes such as cell proliferation, migration, invasion, apoptosis and epithelial-mesenchymal transition, as well as angiogenesis and responsiveness to treatment. In many cancer types (such as lung, prostate, gastric, breast, bladder, ovarian, colorectal, and pancreatic cancer, and osteosarcoma), miR-330-5p acts as an anti-tumor agent. These cancers have low levels of miR-330-5p that leads to the upregulation of the tumor promotor target genes leading to tumor progression. Here, overexpression of miR-330-5p using miRNA inducers can prevent tumor development. Dual roles of miR-330-5p have been also indicated in the thyroid, liver and cervical cancers. Moreover, miR-330-3p exhibits pro-tumorigenesis effects in lung cancer, pancreatic cancer, osteosarcoma, bladder cancer, and cervical cancer. Here, downregulation of miR-330-3p using miRNA inhibitors can prevent tumor development. Demonstrated in breast and liver cancers, miR-330-3p also has dual roles. Importantly, the activities of miR-330-3p and/or miR-330-5p are regulated by upstream regulators long non-coding RNAs (lncRNAs), including circular and linear lncRNAs. This review comprehensively explained miR-330-3p and miR-330-5p role in development of cancers, while highlighting their downstream target genes and upstream regulators as well as possible therapeutic strategies.

Antagonistic Roles of the Tumor Suppressor miR-210-3p and Oncomucin MUC4 Forming a Negative Feedback Loop in Pancreatic Adenocarcinoma

Simple Summary

We aimed at characterizing microRNAs activated downstream of MUC4-associated signaling in pancreatic adenocarcinoma. We investigated the MUC4-miR-210-3p reciprocal regulation and deciphered miR-210-3p biological roles in vitro and in vivo. We showed a MUC4-miR-210-3p negative feedback loop that involves NF-κB in PDAC-derived cells and the miR-210-3p anti-tumoral functions, suggesting a complex balance between antagonistic pro-oncogenic functions of the oncomucin MUC4 and anti-tumoral roles of the miR-210-3p.

Abstract

Background: Pancreatic adenocarcinoma (PDAC) is a deadly cancer with an extremely poor prognosis. MUC4 membrane-bound mucin is neoexpressed in early pancreatic neoplastic lesions and is associated with PDAC progression and chemoresistance. In cancers, microRNAs (miRNAs, small noncoding RNAs) are crucial regulators of carcinogenesis, chemotherapy response and even metastatic processes. In this study, we aimed at identifying and characterizing miRNAs activated downstream of MUC4-associated signaling in pancreatic adenocarcinoma. MiRnome analysis comparing MUC4-KD versus Mock cancer cells showed that MUC4 inhibition impaired miR-210-3p expression. Therefore, we aimed to better understand the miR-210-3p biological roles. Methods: miR-210-3p expression level was analyzed by RT-qPCR in PDAC-derived cell lines (PANC89 Mock and MUC4-KD, PANC-1 and MiaPACA-2), as well as in mice and patients tissues. The MUC4-miR-210-3p regulation was investigated using luciferase reporter construct and chromatin immunoprecipitation experiments. Stable cell lines expressing miR-210-3p or anti-miR-210-3p were established using CRISPR/Cas9 technology or lentiviral transduction. We evaluated the biological activity of miR-210-3p in vitro by measuring cell proliferation and migration and in vivo using a model of subcutaneous xenograft. Results: miR-210-3p expression is correlated with MUC4 expression in PDAC-derived cells and human samples, and in pancreatic PanIN lesions of Pdx1-Cre; LstopL-KrasG12D mice. MUC4 enhances miR-210-3p expression levels via alteration of the NF-κB signaling pathway. Chromatin immunoprecipitation experiments showed p50 NF-κB subunit binding on miR-210-3p promoter regions. We established a reciprocal regulation since miR-210-3p repressed MUC4 expression via its 3′-UTR. MiR-210-3p transient transfection of PANC89, PANC-1 and MiaPACA-2 cells led to a decrease in cell proliferation and migration. These biological effects were validated in cells overexpressing or knocked-down for miR-210-3p. Finally, we showed that miR-210-3p inhibits pancreatic tumor growth and proliferation in vivo. Conclusion: We identified a MUC4-miR-210-3p negative feedback loop in early-onset PDAC, but also revealed new functions of miR-210-3p in both in vitro and in vivo proliferation and migration of pancreatic cancer cells, suggesting a complex balance between MUC4 pro-oncogenic roles and miR-210-3p anti-tumoral effects.

Downregulation of miR-29c promotes muscle wasting by modulating the activity of leukemia inhibitory factor in lung cancer cachexia

BACKGROUND

Cancer cachexia is a wasting disorder characterized by significant weight loss, and is attributed to skeletal muscle weakness. In the process of cancer development, microRNAs act as oncogenes or tumor suppressors. Moreover, they are implicated in muscle development and wasting. This study sought to explore the mechanisms and correlation between miR-29c and muscle wasting in lung cancer cachexia.

METHODS

Data for expression analysis were retrieved from the Cancer Genome Atlas (TCGA) database. qRT-PCR analyses were performed to explore the expression levels of miR-29c and Leukemia Inhibitory Factor (LIF). Lewis lung carcinoma (LLC) cell line was used to establish a cachexia model to explore the functions of miR-29c and LIF in lung cancer cachexia. Furthermore, in vitro (in C2C12 myotubes) and in vivo (in LLC tumor-bearing mice) experiments were performed to explore the mechanisms of miR-29c and LIF in lung cachexia.

RESULTS

Analysis of the lung cancer cachexia model showed that miR-29c was down-regulated, and its expression was negatively correlated with muscle catabolic activity. Overexpression of miR-29c mitigated the cachectic phenotype. Mechanistic studies showed that LIF was a direct target gene of miR-29c, and LIF was upregulated in vitro and in vivo. Analysis showed that LIF promoted muscle wasting through the JAK/STAT and MAP-kinase pathways.

CONCLUSIONS

The findings indicated that miR-29c was negatively correlated with the cachectic phenotype, and the miR-29c-LIF axis is a potential therapeutic target for cancer cachexia.

MicroRNA miR-29a Inhibits Colon Cancer Progression by Downregulating B7-H3 Expression: Potential Molecular Targets for Colon Cancer Therapy

MiR-29a belongs to one of the subtypes of miRNAs known as non-coding single-stranded RNAs and is preferentially expressed in normal tissues. B7-H3, a member of the B7/CD28 immunoglobulin superfamily, was shown to be overexpressed in several solid malignant tumors, including colon cancer. In addition, it is associated with tumor progression and poor prognosis. We used immunohistochemical and Western blotting to assess B7-H3 protein expression levels in colon cancer and adjacent normal tissues and then compared their relationships with clinicopathological factors. Quantitative real-time reverse-transcription PCR was used to assess B7-H3 and miRNA-29a mRNA expression levels, and then their relationship and clinical significance were evaluated. In addition, colon cancer Caco-2 cells, which constitutively overexpress B7-H3, were transfected with lentivirus particles for miR-29a upregulation. Invasion and migration assays were carried out in vitro along with the establishment of a subcutaneous xenograft model in vivo to determine the role of miRNA-29a in colon cancer progression. The B7-H3 protein showed elevated expression in colon carcinoma and was relevant to TNM staging, lymph node metastasis, and reduced survival. Meanwhile, miR-29a was preferentially expressed in normal colon tissues, while B7-H3 transcript levels had no marked differences between tumor and normal tissue specimens. In vitro, miR-29a upregulation resulted in reduced B7-H3 expression. Furthermore, miR-29a upregulation reduced the invasive and migratory abilities of colon carcinoma cells. In animal models, upregulation of miR-29a slowed down the growth of subcutaneous xenotransplanted tumors and resulted in prolonged survival time. MiR-29a downregulates B7-H3 expression and accordingly inhibits colon cancer progression, invasion, and migration, indicating miR-29a and B7-H3 might represent novel molecular targets for advanced immunotherapy in colon cancer.

A novel circ_0099999/miR-330-5p/FSCN1 ceRNA crosstalk in pancreatic cancer

BACKGROUND

Pancreatic cancer is a lethal malignancy in both sexes throughout the world. Circular RNAs (circRNAs) have been implicated in the development of pancreatic cancer by operating as competing endogenous RNAs (ceRNAs). Here, we explored circ_0099999-mediated ceRNA activity in regulating pancreatic tumorigenesis.

METHODS

Ribonuclease R (RNase R) and subcellular localization assays were utilized to characterize circ_0099999. The levels of circ_0099999, microRNA (miR)-330-5p, and fascin actin-bundling protein 1 (FSCN1) were gauged by quantitative real-time PCR (qRT-PCR) and western blot. Cell proliferation, colony formation, apoptosis, migration, and invasion were evaluated by the Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry, and transwell assays, respectively. The levels of glucose consumption and lactate production were determined using the assay kits. A direct relationship between miR-330-5p and circ_0099999 or FSCN1 was validated by dual-luciferase reporter assay. Tumour xenograft assays were used to analyse the role of circ_0099999 in vivo.

RESULTS

Circ_0099999 was highly up-regulated in pancreatic cancer tissues and cells. Knockdown of circ_0099999 impeded cell proliferation, migration, invasion, glycolysis, and promoted apoptosis in vitro, as well as diminished tumour growth in vivo. Circ_0099999 targeted miR-330-5p, and miR-330-5p was a downstream mediator of circ_0099999 function. FSCN1 was a direct and functional target of miR-330-5p. Furthermore, circ_0099999 operated as a ceRNA for miR-330-5p to modulate FSCN1 expression.

CONCLUSIONS

Our findings established a novel causal mechanism, circ_0099999/miR-330-5p/FSCN1 ceRNA crosstalk, in regulating pancreatic carcinogenesis and provided that inhibition of circ_0099999 might have therapeutic benefits in pancreatic cancer.

Dysregulation of miRNAs Targeting the IGF-1R Pathway in Pancreatic Ductal Adenocarcinoma

Background: Pancreatic ductal adenocarcinoma (PDAC), the most prevalent neoplastic lethal pancreatic disease, has a poor prognosis and an increasing incidence. The insulin-like growth factor-1 receptor (IGF-1R) signaling pathway is considered to be a contributing factor to the progression, metastasis, and therapy resistance of PDAC. Currently available treatment options for PDAC are limited, but microRNAs (miRNAs) may represent a new therapeutic strategy for targeting genes involved in the IGF-1R signaling pathway. Method: We investigated the expression levels of 21 miRNAs involved in the IGF-1R signaling pathway in pancreatic tissue from 38 patients with PDAC and 11 controls (five patients with chronic pancreatitis and six patients with normal pancreatic tissue). Results: We found 19 differentially expressed miRNAs between the PDAC cases and the controls. In particular, miR-100-5p, miR-145-5p, miR-29c-3p, miR-9-5p, and miR-195-5p were exclusively downregulated in PDAC tissue but not in chronic pancreatitis or normal pancreatic tissues; both control types presented similar levels. We also identified miR-29a-3p, miR-29b-3p, and miR-7-5p as downregulated miRNAs in PDAC tissues as compared with normal tissues but not with pancreatitis tissues. Conclusions: We identified a panel of miRNAs that could represent putative therapeutic targets for the development of new miRNA-based therapies for PDAC.

MicroRNA in combination with HER2-targeting drugs reduces breast cancer cell viability in vitro

HER2-positive (HER2 +) breast cancer patients that do not respond to targeted treatment have a poor prognosis. The effects of targeted treatment on endogenous microRNA (miRNA) expression levels are unclear. We report that responsive HER2 + breast cancer cell lines had a higher number of miRNAs with altered expression after treatment with trastuzumab and lapatinib compared to poorly responsive cell lines. To evaluate whether miRNAs can sensitize HER2 + cells to treatment, we performed a high-throughput screen of 1626 miRNA mimics and inhibitors in combination with trastuzumab and lapatinib in HER2 + breast cancer cells. We identified eight miRNA mimics sensitizing cells to targeted treatment, miR-101-5p, mir-518a-5p, miR-19b-2-5p, miR-1237-3p, miR-29a-3p, miR-29c-3p, miR-106a-5p, and miR-744-3p. A higher expression of miR-101-5p predicted better prognosis in patients with HER2 + breast cancer (OS: p = 0.039; BCSS: p = 0.012), supporting the tumor-suppressing role of this miRNA. In conclusion, we have identified miRNAs that sensitize HER2 + breast cancer cells to targeted therapy. This indicates the potential of combining targeted drugs with miRNAs to improve current treatments for HER2 + breast cancers.

Mucin expression, epigenetic regulation and patient survival: A toolkit of prognostic biomarkers in epithelial cancers

Twenty mucin genes have been identified and classified in two groups (encoding secreted and membrane-bound proteins). Secreted mucins participate in mucus formation by assembling a 3-dimensional network via oligomerization, whereas membrane-bound mucins are anchored to the outer membrane mediating extracellular interactions and cell signaling. Both groups have been associated with carcinogenesis progression in epithelial cancers, and are therefore considered as potential therapeutic targets. In the present review, we discuss the link between mucin expression patterns and patient survival and propose mucins as prognosis biomarkers of epithelial cancers (esophagus, gastric, pancreatic, colorectal, lung, breast or ovarian cancers). We also investigate the relationship between mucin expression and overall survival in the TCGA dataset. In particular, epigenetic mechanisms regulating mucin gene expression, such as aberrant DNA methylation and histone modification, are interesting as they are also associated with diagnosis or prognosis significance. Indeed, mucin hypomethylation has been shown to be associated with carcinogenesis progression and was linked to prognosis in colon cancer or pancreatic cancer patients. Finally we describe the relationship between mucin expression and non-coding RNAs that also may serve as biomarkers. Altogether the concomitant knowledge of specific mucin-pattern expression and epigenetic regulation could be translated as biomarkers with a better specificity/sensitivity performance in several epithelial cancers.

microRNA Sequencing of CD34+ Sorted Adipose Stem Cells Undergoing Endotheliogenesis

While several microRNAs (miRNAs) that regulate the endotheliogenesis and further promote angiogenesis have been identified in various cancers, the identification of miRNAs that can drive the differentiation of adipose derived stromal/stem cells (ASCs) into the endothelial lineage has been largely unexplored. In this study, CD34+ ASCs sorted using magnetic bead separation were induced to differentiate along the endothelial pathway. miRNA sequencing of ASCs at day 3, 9, and 14 of endothelial differentiation was performed on Ion Proton sequencing system. The data obtained by this high-throughput method were aligned to the human genome HG38, and the differentially expressed miRNAs during endothelial differentiation at various time points (day 3, 9, and 14) were identified. The gene targets of the identified miRNAs were obtained through miRWalk database. The network-pathway analysis of miRNAs and their targets was performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) bioinformatic tools to determine the potential candidate miRNAs that promote endothelial differentiation. Based on these analyses, six upregulated miRNAs (miR-181a-5p, miR-330-5p, miR-335-3p, miR-15b-5p, miR-99a-5p, and miR-199a-5p) and six downregulated miRNAs (miR-145-5p, miR-155-5p, miR-193a-3p, miR-125a-5p, miR-221-5p, and miR-222-3p) were chosen for further studies. In vitro evaluation of these miRNAs to induce endothelial differentiation when transfected into CD34+ sorted ASCs was studied using Von Willebrand Factor (VWF) staining and quantitative real time-polymerase chain reaction (qRT-PCR). Our results suggest that miRNAs: 335-5p, 330-5p, 181a-5p and anti-miRNAs: 125a-5p, 145-5p can likely induce endothelial differentiation in CD34+ sorted ASCs. Further studies are clearly required to elucidate the specific mechanisms on how miRNAs or anti-miRNAs identified through bioinformatics approach can induce the endotheliogenesis in ASCs.

Effect of 7,12-Dimethylbenz(α)anthracene on the Expression of miR-330, miR-29a, miR-9-1, miR-9-3 and the mTORC1 Gene in CBA/Ca Mice

BACKGROUND/AIM

Development of malignant tumors is preceded by molecular biological events. Our aim was to establish an assay panel by using miRNAs and other genes for the rapid screening of potential carcinogens or chemopreventive agents.

MATERIALS AND METHODS

Six male and 6 female CBA/Ca mice received 20 mg/bwkg 7,12-dimethylbenz(α)anthracene (DMBA) intraperitoneally, and 24 h later RNA was isolated from parenchymal organs. Expression of miR-330, miR-29a, miR-9-1, miR-9-3 and mTORC1 was analysed by real time polymerase chain reaction and compared to non-treated controls.

RESULTS

DMBA caused significant alterations in the expression of the studied genes. The most profound changes were the strongly elevated miR-9-3 and mTORC1 expressions in female mice in all organs studied.

CONCLUSION

miR-9-3 and mTORC1 expression in female mice were found to be the most suitable biomarkers for rapid identification of possible carcinogenic effects.

circSFMBT1 promotes pancreatic cancer growth and metastasis via targeting miR-330-5p/PAK1 axis

Pancreatic cancer (PC) is one of the most common and lethal cancers that affects millions of people around the world. The prognosis of PC is poor with very limited effective treatments. Here, we fully investigated the function and underlying mechanism of circSFMBT1 (hsa_circ_0066147) in PC. Real-time quantitative PCR, Western blotting, and immunohistochemistry were used to examine levels of circSFMBT1, miR-330-5p, PAK1 (p21-activated kinase 1), or proliferation/metastasis-related proteins. Colony formation assay, flow cytometry, and transwell assay detected the roles of circSFMBT1 and miR-330-5p in cell apoptosis, proliferation, migration, and invasion of PC cells, respectively. Dual luciferase assay and RNA immunoprecipitation were used to validate the interactions of circSFMBT1/miR-330-5p and miR-330-5p/PAK1. Fluorescence in situ hybridization was performed to examine the subcellular localization of circSFMBT1 and miR-330-5p. Subcutaneous tumor growth was monitored in nude mice and in vivo metastasis was examined as well following injection of PC cells into the tail vein. This study demonstrated that circSFMBT1 and PAK1 were up-regulated in PC tissues and cells, while miR-330-5p was down-regulated. circSFMBT1 directly bound miR-330-5p and inhibited its expression. In addition, circSFMBT1 promoted proliferation, migration, and invasion of PC cells through up-regulating proliferation-related proteins and down-regulating apoptosis-related proteins via miR-330-5p. miR-330-5p directly bound PAK1 mRNA and suppressed proliferation, migration, invasion, and epithelial-mesenchymal transition process via targeting PAK1 in PC cells. Further, knockdown circSFMBT1 increased miR-330-5p level, but decreased PAK1 expression and repressed tumor growth and metastasis in vivo. Taken together, circSFMBT1 promotes proliferation and metastasis of PC via regulating miR-330-5p/PAK1 pathway as a miR-330-5p sponge.

MicroRNA-29a functions as a tumor suppressor through targeting STAT3 in laryngeal squamous cell carcinoma

Laryngeal squamous cell carcinoma (LSCC) is a common head and neck cancer with high mortality in developing countries. A comprehensive understanding of the molecular mechanisms of tumor progression in laryngeal cancer is needed for new treatment strategies. MicroRNA-29a has been emerged as a critical miRNA in various cancers, and shown to regulate multiple oncogenic processes. In this study, we investigated the tumor suppressive role of miRNA-29a in laryngeal squamous cell carcinoma. We performed cell-based functional analysis after overexpression of miR-29a in AMC-HN-8 and HEP2 cells in vitro. It turned out that ectopic expression of miR-29a significantly inhibited cell proliferation, invasion, and migration in two LSCC cell lines (AMC-HN-8 and Hep2) in vitro. Further downstream target analysis by western blotting and luciferease reporter assay showed that overexpression of miR-29a significantly downregulated expression of STAT3, and STAT3 is a putative direct target of miR-29a in LSCC. In addition, the tumor suppressive function of miR-29a can be abrogated by forced expression of STAT3. Taken together, our data suggest that miR-29a functions as a tumor suppressor through targeting STAT3 in laryngeal squamous cell carcinoma.

miR-330 Regulates Colorectal Cancer Oncogenesis by Targeting BACH1

Purpose: Based on WHO report, colorectal cancer (CRC) is the second cause of death among patients with cancer worldwide. Dysregulation of miRNAs expressions has been demonstrated in different human cancers, especially CRC. Studies have shown that miR-330 could act as both TS-miR and/or oncomiR in different types of cancers. BACH1 is also identified as a transcription factor, which is involved in ontogenesis. In this study, we evaluated the CRC suppression via silencing of BACH1 by small silencer molecule called miR-330.

Methods: Firstly, we analyzed the BACH1, miR-330-3p and miR-330-5p expressions according to the colon adenocarcinoma (COAD) and rectal adenocarcinoma (READ) project established from a patient of the colon and rectal cancer patients in The Cancer Genome Atlas (TCGA) database. The targeting of BACH1 via miR-330 in human CRC cells was evaluated by Vejnar bioinformatics methods, and confirmed by qRT-PCR and western blot analysis. Proliferation was performed by MTT assay. The MMP9, CXCR4, and VEGFR proteins were measured by western blotting.

Results: The analysis of BACH1, miR-330-3p, and miR-330-5p expressions according to the COAD and READ projects showed that BACH1 was overexpressed, but miR-330-3p and miR330-5p were reduced in CRC tumors compared to normal controls. The miR-330 induction prevented proliferation of CRC cell by targeting BACH1 mRNA, which represses MMP9, C-X-C chemokine receptor type 4 (CXCR4), and vascular endothelial growth factor receptor (VEGFR) proteins expressions.

Conclusion: Our results suggested that BACH1 is a potential target for miR-330 in CRC cells. The miR-330 induction inhibits CRC cells proliferation by suppressing BACH1 expression in posttranscriptional level. It was suggested that targeting of BACH1 via miRNA such as miR-330 could be a valid strategy in the field of CRC targeted therapy via modulating the oncogenic signaling pathway.

Elevation of microRNA-512-5p inhibits MUC1 to reduce radioresistance in cervical cancer

Researches about the role of several microRNAs (miRNAs) in cervical cancer were performed by previous studies, but the function of miR-512-5p in cervical cancer is rare to see. Thus, we aimed to investigate the effect and mechanism of miR-512-5p on radiosensitivity in cervical cancer by regulating MUC1 expression. First, 111 patients with cervical cancer were divided into radiotherapy sensitive group and radiotherapy resistant group. After that, miR-512-5p expression in cancer tissues from two groups was detected. Next, RT-qPCR was used to detect miR-512-5p expression in radiotherapy resistant cervical cancer cells SiHa and radiotherapy sensitive cervical cancer cells Me180. Moreover, SiHa and Me180 cells were treated with miR-512-5p overexpression and MUC1 poor expression plasmids. With 0 Gy, 2 Gy, 4 Gy, 6 Gy and 8 Gy irradiation, proliferation, colony formation ability and apoptosis of cervical cancer cells were determined. Also, cell lines that overexpressed miR-512-5p and overexpressed MUC1 were then constructed to observe the changes in cell radiosensitivity. MiR-512-5p was down-regulated and MUC1 was up-regulated in radiotherapy resistant cervical cancer tissues and cells. Overexpression of miR-512-5p and down-regulation of MUC1 increased the apoptosis and reduced cell survival rate of cervical cancer cells after radiotherapy. Overexpression of miR-512-5p reversed the effect of MUC1 overexpression on decreasing cell apoptosis and elevating cell survival rate of cervical cancer cells. Our study provides evidence that elevation of miR-512-5p contributes to the reduction of radioresistance in cervical cancer cells by inhibiting MUC1 expression.

miR-29a Promotes the Neurite Outgrowth of Rat Neural Stem Cells by Targeting Extracellular Matrix to Repair Brain Injury

Neural stem cells (NSCs) can generate new neurons to repair brain injury and central nervous system disease by promoting neural regeneration. MicroRNAs (miRNAs) involve in neural development, brain damage, and neurological diseases repair. Recent reports show that several miRNAs express in NSCs and are important to neurogenesis. Neurites play a key role in NSC-related neurogenesis. However, the mechanism of NSC neurite generation is rarely studied. We surprisingly noticed that the neurites increased after bone morphogenetic protein (BMP) treatment in rat NSCs. This process was accompanied by the dynamic change of miRNA-29. Then we discovered that miR-29a regulated neural neurites in rat hippocampus NSCs. Overexpression of miR-29a reduced the cell soma area and promoted the neurite outgrowth of NSCs. Cell soma area became small, whereas the number of neurite increased. Moreover, neurite complexity increased dramatically, with more primary and secondary branches after miR-29a overexpression. In addition, miR-29a overexpression still maintained the stemness of NSCs. Besides, we identified that miR-29a can promote the neurite outgrowth by targeting extracellular matrix-related genes like Fibrillin 1 (Fbn1), Follistatin-like 1 (Fstl1), and laminin subunit gamma 2 (Lamc2). These findings may provide a novel role of miR-29a to regulate neurite outgrowth and development of NSCs. We also offered a possible theoretical basis to the migration mechanism of NSCs in brain development and damage repair.

Mucin glycoproteins block apoptosis; promote invasion, proliferation, and migration; and cause chemoresistance through diverse pathways in epithelial cancers

Overexpression of mucin glycoproteins has been demonstrated in many epithelial-derived cancers. The significance of this overexpression remains uncertain. The aim of this paper was to define the association of mucin glycoproteins with apoptosis, cell growth, invasion, migration, adhesion, and clonogenicity in vitro as well as tumor growth, tumorigenicity, and metastasis in vivo in epithelial-derived cancers by performing a systematic review of all published data. A systematic review of PubMed, Embase, and the Cochrane Central Register of Controlled Trials was performed to identify all papers that evaluated the association between mucin glycoproteins with apoptosis, cell growth, invasion, migration, adhesion, and clonogenicity in vitro as well as tumor growth, tumorigenicity, and metastasis in vivo in epithelial-derived cancers. PRISMA guidelines were adhered to. Results of individual studies were extracted and pooled together based on the organ in which the cancer was derived from. The initial search revealed 2031 papers, of which 90 were deemed eligible for inclusion in the study. The studies included details on MUC1, MUC2, MUC4, MUC5AC, MUC5B, MUC13, and MUC16. The majority of studies evaluated MUC1. MUC1 overexpression was consistently associated with resistance to apoptosis and resistance to chemotherapy. There was also evidence that overexpression of MUC2, MUC4, MUC5AC, MUC5B, MUC13, and MUC16 conferred resistance to apoptosis in epithelial-derived cancers. The overexpression of mucin glycoproteins is associated with resistance to apoptosis in numerous epithelial cancers. They cause resistance through diverse signaling pathways. Targeting the expression of mucin glycoproteins represents a potential therapeutic target in the treatment of epithelial-derived cancers.

Overexpression of miR-939-3p predicts poor prognosis and promotes progression in lung cancer

BACKGROUND

Lung cancer is the main cancer-related deaths worldwide. In this study, we explored the clinical prognostic significance and functional role of miR-939-3p in lung cancer.

METHODS

We analyzed the expression of miR-939-3p in lung cancer tissues and cells by qRT-PCR. The prognostic significance of miR-939-3p was investigated using the Kaplan-Meier survival and Cox regression analyses. The CCK-8 assay was used to determine the role of miR-939-3p in cell proliferation. Transwell assays were used to determine the effects of miR-939-3p on cell migration and invasion abilities.

RESULTS

The expression of miR-939-3p was upregulated in cancer tissues and cell lines compared with adjacent normal tissues and normal cells, respectively. The upregulated miR-939-3p was significantly associated with lymph node metastasis, TNM stage and poor prognosis of lung cancer patients. After the transfection of miR-939 mimic, overexpression of miR-939-3p promoted lung cancer cell proliferation, migration, and invasion.

CONCLUSION

These findings suggested that miR-939-3p acts as an oncogene and promotes cell proliferation, migration, and invasion in lung cancer. miR-939-3p may be a potential independent prognostic biomarker in lung cancer.

Silencing Long Non-coding RNA LINC01224 Inhibits Hepatocellular Carcinoma Progression via MicroRNA-330-5p-Induced Inhibition of CHEK1

Hepatocellular carcinoma (HCC) accounts for approximately 85%–90% of primary liver cancers. Based on in silico analysis, differentially expressed long non-coding RNA (lncRNA) LINC01224 in HCC, the downstream microRNA (miRNA) miR-330-5p, and its target gene checkpoint kinase 1 (CHEK1) were selected as research subjects. Herein, this study was designed to evaluate their interaction effects on the malignant phenotypes of HCC cells. LINC01224 and CHEK1 were upregulated and miR-330-5p was downregulated in HCC cells. miR-330-5p shared negative correlations with LINC01224 and CHEK1, and LINC01224 shared a positive correlation with CHEK1. Notably, LINC01224 could specifically bind to miR-330-5p, and CHEK1 was identified as a target gene of miR-330-5p. When LINC01224 was silenced or miR-330-5p was elevated, the sphere and colony formation abilities and proliferative, migrative, and invasive potentials of HCC cells were diminished, while cell cycle arrest and apoptosis were enhanced. Moreover, LINC01224 induced HCC progression in vitro and accelerated tumor formation in nude mice by increasing CHEK1 expression. The key findings of the present study demonstrated that silencing LINC01224 could downregulate the expression of CHEK1 by competitively binding to miR-330-5p, thus inhibiting HCC progression. This result highlights the LINC01224/miR-330-5p/CHEK1 axis as a novel molecular mechanism involved in the pathology of HCC.

MiR-140-5p inhibits cell proliferation and metastasis by regulating MUC1 via BCL2A1/MAPK pathway in triple negative breast cancer

Noncoding RNAs play important roles in the progression of malignant tumors, including triple negative breast cancer (TNBC). Accumulating evidence supported the involvement of the oncogenic MUC1 in tumor metastasis. Our study aimed to explore the roles of miR-140-5p and MUC1 in TNBC and identify the potential underlying mechanisms. In the present study, we found that miR-140-5p expression was significantly decreased in TNBC tissues and associated with advanced clinical features and poor prognosis. MiR-140-5p overexpression suppressed TNBC cells proliferation, invasion ability in vitro and reduced tumor growth in vivo. Subsequently, MUC1 was verified to be a direct target of miR-140-5p in TNBC. Furthermore, we revealed that MUC1 could regulate MAPK pathway through regulating BCL2A1 expression in TNBC. Thus, our study indicated that miR-140-5p might regulate MUC1 to suppress TNBC cells proliferation and metastasis by regulating BCL2A1/MAPK pathway, suggesting miR-140-5p could serve as a potential therapeutic target for TNBC.

MicroRNA‑330‑5p inhibits osteosarcoma cell growth and invasion by targeting the proto‑oncogene survivin

Increasing evidence has suggested the crucial role of the dysregulation of microRNAs (miRNAs) in osteosarcoma (OS) progression. MicroRNA (miR)-330-5p has been reported to exert tumor suppressive effects in various types of human cancer. However, the role of miR-330-5p in the development of OS and the underlying mechanism remain to be clarified. In the present study, miR-330-5p expression was found to be significantly decreased in OS tissues and cell lines. In addition, low miR-330-5p expression was highly correlated with the overall survival and clinical stage of OS. Overexpression of miR-330-5p inhibited the viability, migration and invasion, and promoted the apoptosis of OS cells, as well as induced cell cycle arrest at the G₂/M phase. Subsequently, the proto-oncogene survivin was identified as a functional target of miR-330-5p, and this was validated using a luciferase reporter assay. It was also demonstrated that survivin expression was markedly increased in OS tissues, and that it was negatively correlated with the expression of miR-330-5p. Furthermore, overexpression of survivin significantly abrogated the tumor-suppressive effect induced by miR-330-5p on OS cells. In conclusion, these results revealed that the miR-330-5p/survivin axis has a significant tumor-suppressive effect on OS, and may serve as a diagnostic and therapeutic target for the treatment of OS.

miR-330 suppresses EMT and induces apoptosis by downregulating HMGA2 in human colorectal cancer

MicroRNAs (miRNAs) are important molecular regulatorsof cellular signaling and behavior. They alter gene expression by targeting messenger RNAs, including those encoding transcriptional regulators, such as HMGA2. While HMGA2 is oncogenic in various tumors, miRNAs may be oncogenic or tumor suppressive. Here, we investigate the expression of HMGA2 and the miRNA miR-330 in a patient with colorectal cancer (CRC) samples and their effects on oncogenic cellular phenotypes. We found that HMGA2 expression is increased and miR-330 expression is decreased in CRCs and each predicts poor long-term patient survival. Stably increased miR-330 expression in human colorectal cancer cells (HCT116) and SW480 CRC cell lines downregulate the oncogenic expression of HMGA2, a predicted miR-330 target. Additionally, this promotes apoptosis and decreases cell migration and viability. Consistently, it also decreases protein-level expression of markers for epithelial-to-mesenchymal-transition (Snail-1, E-cadherin, and Vascular endothelial growth factor receptors) and transforming growth factor β signaling (SMAD3), as well as phospho- Protein kinase B (AKT) and phospho-STAT3 levels. We conclude that miR-330 acts as a tumor suppressor miRNA in CRC by suppressing HMGA2 expression and reducing cell survival, proliferation, and migration. Thus, we identify miR-330 as a promising candidate for miRNA replacement therapy for patients with CRC.

mTOR/miR-145-regulated exosomal GOLM1 promotes hepatocellular carcinoma through augmented GSK-3β/MMPs

Golgi membrane protein 1 (GOLM1/GP73) is a serum marker of hepatocellular carcinoma (HCC). We have previously shown that mTOR promoted tumorigenesis of HCC through stimulating GOLM1 expression. In this study, we demonstrated that the mammalian target of rapamycin (mTOR) was a negative regulator of microRNA-145 (miR-145) expression. miR-145 inhibited GOLM1 expression by targeting a coding sequence of GOLM1 gene. GOLM1 and miR-145 were inversely correlated in human HCC tissues. GOLM1-enriched exosomes activated the glycogen synthase kinase-3β/matrix metalloproteinases (GSK-3β/MMPs) signaling axis of recipient cells and accelerated cell proliferation and migration. In contrast, miR-145 suppressed tumorigenesis and metastasis. We suggest that mTOR/miR-145/GOLM1 signaling pathway should be targeted for HCC treatment.

Skp2 Expression Is Inhibited by Arsenic Trioxide through the Upregulation of miRNA-330-5p in Pancreatic Cancer Cells

Arsenic trioxide (ATO) has been found to exert its anti-cancer activity in various human malignancies. In our previous report, we have shown that ATO inhibited cell growth and invasion via downregulation of Skp2 in pancreatic cancer (PC) cells. It has been extensively demonstrated that microRNAs (miRNAs) play a pivotal role in tumorigenesis. ATO might induce PC cell apoptosis and regulate Skp2 downregulation through the regulation of miRNAs. One study has demonstrated that miR-330-5p exerts a tumor-suppressive function in PC cell lines. Here, we investigated the role of miRNA-330-5p in ATO-mediated anti-tumor activity and explored whether ATO could regulate miR-330-5p in PC cells. We found that ATO treatment upregulated the expression of miR-330-5p. Moreover, miR-330-5p inhibitor rescued the ATO-mediated tumor-suppressive function. The combination of miR-330-5p mimic with ATO reduced cell growth, motility, and invasion, and enhanced apoptosis to a greater degree in PC cells. This study suggests that the combination of miR-330-5p mimic with ATO may be a potential therapeutic strategy for the treatment of PC.

Functional polymorphisms in LncRNA HOTAIR contribute to susceptibility of pancreatic cancer

Background

Pancreatic cancer (PC) remains one of the most aggressive cancers worldwide. However, genetic factors underlying PC susceptibility remain largely unclear. Long noncoding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) acts as an oncogene and its genetic variation has been linked to many cancers. However, the associations between genetic variants in HOTAIR gene and PC risk has not yet been reported.

Methods

A two-stage, case–control study was conducted to investigate the associations between HOTAIR SNPs and the PC risk. Dual luciferase reporter assay and real-time -PCR (RT-PCR) was conducted to evaluate the potential regulatory function of HOTAIR rs4759314 and rs200349340.

Results

We found the minor alleles of rs4759314 (OR = 1.76; 95 CI 1.37–2.25; P = 0.001) and rs200349340 (OR = 1.32; 95 CI 1.12–1.56; P = 0.001) were significantly associated with PC susceptibility. In functional experiments, we found subjects carrying the minor alleles of rs4759314 and rs200349340 had significantly higher HOTAIR RNA levels (mean ± SD) than those carrying the major alleles in PC tissues. For rs4759314, cells transfected with rs4759314 -G allele construct showed higher relative luciferase activity; while for rs200349340, cells transfected with rs200349340 -G allele construct showed more sensitive change of the relative luciferase activity.

Conclusion

Our studies revealed that functional SNP rs4759314 and rs200349340 of HOTAIR had strong associations with PC susceptibility. These findings elucidate that functional genetic variants influencing lncRNA expression may explain a portion of PC genetic basis.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0761-x) contains supplementary material, which is available to authorized users.

miR-29a contributes to breast cancer cells epithelial-mesenchymal transition, migration, and invasion via down-regulating histone H4K20 trimethylation through directly targeting SUV420H2

Breast cancer is the most prevalent cancer in women worldwide, which remains incurable once metastatic. Breast cancer stem cells (BCSCs) are a small subset of breast cancer cells which are essential in tumor formation, metastasis, and drug resistance. microRNAs (miRNAs) play important roles in the breast cancer cells and BCSCs by regulating specific genes. In this study, we found that miR-29a was up-regulated in BCSCs, in aggressive breast cancer cell line and in breast cancer tissues. We also confirmed suppressor of variegation 4–20 homolog 2 (SUV420H2), which is a histone methyltransferase that specifically trimethylates Lys-20 of histone H4 (H4K20), as the target of miR-29a. Both miR-29a overexpression and SUV420H2 knockdown in breast cancer cells promoted their migration and invasion in vitro and in vivo. Furthermore, we discovered that SUV420H2-targeting miR-29a attenuated the repression of connective tissue growth factor (CTGF) and growth response protein-1 (EGR1) by H4K20 trimethylation and promoted the EMT progress of breast cancer cells. Taken together, our findings reveal that miR-29a plays critical roles in the EMT and metastasis of breast cancer cells through targeting SUV420H2. These findings may provide new insights into novel molecular therapeutic targets for breast cancer.

MiRNA detection in cervical exfoliated cells for missed high-grade lesions in women with LSIL/CIN1 diagnosis after colposcopy-guided biopsy

Background

Low-grade squamous intraepithelial lesion/cervical intraepithelial neoplasia grade 1 (LSIL/CIN1) preceded by colposcopy guided biopsy is recommended conservative follow-up, although some of these lesions are actually high-grade lesions, which are missed on an initial colposcopy. Therefore, in this work, we evaluate the potential role of miRNA detection in cervical exfoliated cells in a clinic-based population for predicting missed high-grade lesions in women diagnosed with LSIL/CIN1 after colposcopy-guided biopsy.

Methods

A total number of 177 women with a diagnosis of LSIL/CIN1 obtained by colposcopy-guided biopsy were grouped into two categories according to the histology of the conization specimens: consistent LSIL/CIN1 group (surgical pathology consistent with colposcopic diagnosis) and missed high-grade lesion group (surgical pathology found high-grade lesion). The expression of eight miRNAs, such as miRNA195, miRNA424, miRNA375, miRNA218, miRNA34a, miRNA29a, miRNA16–2, and miRNA20a was detected by real time-quantitative polymerase chain reaction (RT-qPCR) in cervical exfoliated cells of the 177 patients. Pearson Chi-Square was used to compare the performance efficiency of patients’ characteristics. Nonparametric Man-Whitney U test was used to assess differences in miRNA expression. The receiver operating characteristic (ROC) curve was used to assess the performance of miRNA evaluation in detecting missed high-grade lesions.

Results

Among the 177 women with biopsy-confirmed CIN1, 15.3% (27/177) had CIN2+ in the conization specimen (missed high-grade lesion group) and 84.7% (150/177) had CIN1-(consistent LSIL/CIN1 group). The relative expression of miRNA-195 and miRNA-29a in the missed high-grade lesion group was significantly lower than that in the consistent LSIL/CIN1 group. The relative expression of miRNA16–2 and miRNA20a in the missed high-grade lesion group was significantly higher than that in the consistent LSIL/CIN1 group. No significant difference was observed between these two groups regarding the other four miRNAs. Of these significant miRNAs, miRNA29a detection achieved the highest Youden index (0.733), sensitivity (92.6%), positive predictive value (46.2%), negative predictive value (98.3%) and higher specificity (80.7%) when identifying missed high-grade lesions.

Conclusions

Detection of miRNA might provide a new triage for identifying a group at higher risk of missed high-grade lesions in women with colposcopy diagnosis of LSIL/CIN1.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5311-3) contains supplementary material, which is available to authorized users.

Silencing of long noncoding RNA LINC00958 prevents tumor initiation of pancreatic cancer by acting as a sponge of microRNA-330-5p to down-regulate PAX8

Pancreatic cancer (PC) represents a relatively rare but severe malignancy worldwide. Accumulated studies have emphasized the potential of long noncoding RNA (lncRNA) as therapeutic strategies for several human cancers. Thus, we aimed to investigate whether a novel non-coding RNA regulatory circuitry involved in PC. Aberrantly expressed lncRNAs and mRNAs were screened out of microarray database. Following the determination of RNA expression, PANC-1 and BxPC-3 PC cells were adopted, after which the expression of miR-330-5p, PAX8 and LINC00958 were subsequently altered. RNA crosstalk was validated by dual-luciferase reporter gene assay. In order to detect whether LINC00958 could act as ceRNA to competitively sponge miR-330-5p and regulate PAX8, subcellular location of LINC00958 and interaction between LINC00958 and miR-330-5p were measured by FISH and RNA pull down respectively. The epithelial mesenchymal transition (EMT) process, cell invasion, and tumor growth were determined in vitro and in vivo. LINC00958 and PAX8 were up-regulated, while miR-330-5p was down-regulated during PC. LINC00958 mainly expressed in the cytoplasm and LINC00958 competitively sponged miR-330-5p. Upregulated miR-330-5p or downregulated PAX8 inhibited the EMT process as well as the invasion and metastasis ability of the PC cells. Moreover, the results indicated that miR-330-5p negatively targeted PAX8, and LINC00958 ultimately showcasing its ability to bind to miR-330-5p through its interaction with AGO2. Therefore, silencing of LINC00958 may bind to miR-330-5p to inhibit PAX8 in a competitive fashion, thereby preventing the progression of PC.

Circular RNA circRHOT1 is upregulated and promotes cell proliferation and invasion in pancreatic cancer

Aim: We aimed to identify the roles of circRHOT1 in pancreatic cancer. Materials & methods: The circRHOT1 was acquired from our previous study followed by quantitative real-time PCR and fluorescence in situ hybridization validation in pancreatic cancer. We used siRNA and shRNA to explore the function of circRHOT1 in pancreatic cancer cells. Bioinformatic analyses were applied to study the potential mechanism of circRHOT1. Results: The circRHOT1 was upregulated in pancreatic cancer and predominantly located in the cytoplasm. Reducing the circRHOT1 expression may inhibit the pancreatic cancer cell proliferation, invasion and migration. The circRHOT1 may play a role in pancreatic cancer through binding miR-26b, miR-125a, miR-330 and miR-382 to regulate multiple tumor-associated pathways. Conclusion: This study demonstrated that circRHOT1 may serve as an oncogenic circRNA that promotes tumor progression.

A Systematic Review of miR-29 in Cancer

MicroRNAs (miRNA) are small non-coding RNAs (∼22 nt in length) that are known as potent master regulators of eukaryotic gene expression. miRNAs have been shown to play a critical role in cancer pathogenesis, and the misregulation of miRNAs is a well-known feature of cancer. In recent years, miR-29 has emerged as a critical miRNA in various cancers, and it has been shown to regulate multiple oncogenic processes, including epigenetics, proteostasis, metabolism, proliferation, apoptosis, metastasis, fibrosis, angiogenesis, and immunomodulation. Although miR-29 has been thoroughly documented as a tumor suppressor in the majority of studies, some controversy remains with conflicting reports of miR-29 as an oncogene. In this review, we provide a systematic overview of miR-29's functional role in various mechanisms of cancer and introspection on the contradictory roles of miR-29.