Overexpressions of miR-212 are associated with poor prognosis of patients with pancreatic ductal adenocarcinoma

LncRNA ILF3AS1, MMP3, and MMP9 as well as miRNA-212 as emerging novel biomarkers for childhood epilepsy

Background

Globally, approximately 70 million people suffer from epilepsy. Infants constitute a significant percentage of these cases. Hence, there is a significant need for better understanding of the pathophysiology of epilepsy through laboratory and radiological methods for early detection and optimized management. Interleukin enhancer binding factor 3 antisense RNA l (ILF3AS1) is a long non-coding RNA (lncRNA) that enhances the expressions of matrix metalloproteinase 3 (MMP3) and matrix metalloproteinase 9 (MMP9), which are considered to be epileptogenic.

Aim

We aimed to assess the serum expressions of the lncRNAs ILF3AS1, MMP3, and MMP9 along with microRNA-212 (miRNA-212) as predictive biomarkers in children with epilepsy; we also assessed their correlations with magnetic resonance imaging (MRI) findings.

Subjects and Methods

Fifty children with epilepsy and fifty healthy controls were considered in this study. Serum expressions of the lncRNA ILF3AS1 and miRNA-212 were estimated by quantitative real-time polymerase chain reaction (qPCR). Serum concentrations of MMP3 and MMP9 were estimated by enzyme-linked immunosorbent assay (ELISA) in parallel with MRI findings and different baseline biochemical parameters of all the subjects.

Results

The results showed significantly higher levels of lncRNAs ILF3AS1, MMP3, and MMP9 as well as lower levels of miRNA-212 in children with epilepsy compared to the controls. The fold-change of miRNA-212 was a significant negative predictor (odds ratio = 0.153, p = 0.000). The receiver operating characteristic curves (Roc) showed that the areas under the curves for MMP3, MMP9, and lncRNA ILF3AS1 as well as the fold-change for miRNA-212 were 0.659, 0.738, 0.656, and 0.965, respectively. Brain lesions were detected in 15 patients (30%) with epilepsy, whereas the remaining 35 patients (70%) had normal results.

Conclusion

Serum levels of the lncRNA ILF3AS1 among children with epilepsy were higher than those in the control group and were associated with upregulation of both MMP3 and MMP9 as well as downregulation of miRNA-212 expressions, suggesting their predictive utility in monitoring the development of epilepsy; this also means that a treatment plan focusing on the ILF3AS1/miRNA-212/MMP3/MMP9 axis could be an effective strategy for treating epilepsy.

High-Throughput Analysis Reveals miRNA Upregulating α-2,6-Sialic Acid through Direct miRNA-mRNA Interactions

Chemical biology has revealed the importance of sialic acids as a major signal in physiology and disease. The terminal modification α-2,6-sialic acid is controlled by the enzymes ST6GAL1 and ST6GAL2. Dysregulation of this glycan impacts immunological recognition and cancer development. microRNAs (miRNA, miR), noncoding RNAs that downregulate protein expression, are important regulators of glycosylation. Using our recently developed high-throughput fluorescence assay (miRFluR), we comprehensively mapped the miRNA regulatory landscape of α-2,6-sialyltransferases ST6GAL1 and ST6GAL2. We found, contrary to expectations, the majority of miRNAs upregulate ST6GAL1 and α-2,6-sialylation in a variety of cancer cells. In contrast, miRNAs that regulate ST6GAL2 were predominantly downregulatory. Mutational analysis identified direct binding sites in the 3'-untranslated region (UTR) responsible for upregulation, confirming it is a direct effect. The miRNA binding proteins AGO2 and FXR1 were required for upregulation. Our results upend common assumptions surrounding miRNA, arguing that upregulation by these noncoding RNA is common. Indeed, for some proteins, upregulation may be the dominant function of miRNA. Our work also suggests that upregulatory miRNAs enhance overexpression of ST6GAL1 and α-2,6-sialylation, providing another potential pathway to explain the dysregulation observed in cancer and other disease states.

MiR-212 value in prognosis and diagnosis of cancer and its association with patient characteristics: a systematic review and meta-analysis

BACKGROUND

Delayed cancer diagnosis and inefficient cancer prognosis determination are problems faced in cancer diagnosis and treatment. MicroRNAs (miRs), especially miR-212, have shown a promise in cancer diagnosis and prognosis. Herein, we performed a systematic review and meta-analysis to assess the prognostic and diagnostic value of miR-212 level in cancer and evaluated its association with patient characteristics.

METHODS

A fully electronic literature search using related keywords was performed in PubMed, Scopus, Web of Science, Embase, and ScienceDirect databases by June 6, 2021, with no time or language restriction. Meta-analysis was performed to pool survival prognosis data using hazard ratio (HR), association using odds ratio (OR), and diagnostic data using sensitivity, specificity, and diagnostic odds ratio (DOR). Sub-group analysis and meta-regression were performed as appropriate.

RESULTS

Results of 28 studies on 1880 patients showed a poor cancer prognosis with high levels of miR-212 in pancreatic ductal adenocarcinoma (PDAC, HR = 2.451 [1.447-4.149]), and a poor cancer prognosis with low levels of miR-212 in other cancers (HR = 2.514 [2.162-2.923]). Higher alpha-fetoprotein (AFP) level and Edmondson-Steiner grade were factors associated with miR-212 low level incidence. Diagnostic odds ratio 10.688 (3.644-31.348) and SROC AUC of 0.84 confirmed high diagnostic performance of miR-212.

CONCLUSION

Our systematic review and meta-analysis results confirm miR-212 high value in cancer prognosis and diagnosis. High level of miR-212 showed poor prognosis in PDAC and low level of miR-212 showed poor prognosis in other cancers. in conclusion, miR-212 could be a novel potential biomarker in cancer diagnosis and prognosis.

Novel therapies targeting hypoxia mechanism to treat pancreatic cancer

Pancreatic cancer (PC) is one of the deadliest malignancies. The high mortality rate of PC largely results from delayed diagnosis and early metastasis. Therefore, identifying novel treatment targets for patients with PC is urgently required to improve survival rates. A major barrier to successful treatment of PC is the presence of a hypoxic tumor microenvironment, which is associated with poor prognosis, treatment resistance, increased invasion and metastasis. Recent studies have identified a number of novel molecules and pathways in PC cells that promote cancer cells progression under hypoxic conditions, which may provide new therapy strategies to inhibit the development and metastasis of PC. This review summarizes the latest research of hypoxia in PC and provides an overview of how the current therapies have the capacity to overcome hypoxia and improve PC patient treatment. These findings will eventually provide guidance for future PC management and clinical trials and hopefully improve the survival of patients with PC.

Fisetin inhibits proliferation of pancreatic adenocarcinoma by inducing DNA damage via RFXAP/KDM4A-dependent histone H3K36 demethylation

Pancreatic adenocarcinoma (PDAC) is an extremely malignant tumor that is associated with low survival rates. Fisetin is a natural flavonoid that shows diverse antitumor effects, including DNA damage, in various cancers. Increasing studies have demonstrated that epigenetic modifications play critical roles in DNA-damage response. However, the epigenetic regulation mechanism of fisetin in cancers is hardly studied. RFXAP is a critical transcription factor for MHC II molecules, however, its transcriptional role in PDAC is poorly understood. The anti-PDAC effect of fisetin was measured by CCK-8, flow cytometry, xenograft tumor nude mice model. DNA-damage levels were examined by immunofluorescence. Bioinformatics analysis was used to examine the expression of RFXAP and other genes involved in DNA-damage response. ChIP sequencing was used to explore the transcriptional role of RFXAP. The expression of target gene KDM4A was measured by qRT-PCR and western blots. KDM4A promoter activity was analyzed using dual-luciferase reporter assay. RFXAP overexpressing or silencing of PDAC cells was used to explore the effect of RFXAP in DNA damage induced by fisetin. We found that fisetin inhibited cell proliferation and induced DNA damage and S-phase arrest in PDAC. Expression of RFXAP and other DNA-damage response genes were upregulated by fisetin. We revealed that RFXAP expression was relatively low in PDAC and correlated with tumor stage and poor prognosis. Then we explored the transcriptional role of RFXAP and found that RFXAP targeted KDM4A, a special demethylase specific for tri- and dimethylated histone H3K36. We found that overexpression of RFXAP upregulated KDM4A and attenuated methylation of H3K36, thereby impairing DNA repair and enhancing the DNA damage induced by fisetin, while RFXAP silencing showed the opposite effect. We also found the function of fisetin in enhancing the effect of chemotherapy on pancreatic cancer cells. Our findings revealed that fisetin induced DNA damage via RFXAP/KDM4A-dependent histone H3K36 demethylation, thus causing inhibition of proliferation in PDAC.

Potential diagnostic and therapeutic roles of exosomes in pancreatic cancer

Pancreatic cancer (PaCa) is considered an aggressive but still asymptomatic malignancy. Due to the lack of effective diagnostic markers, PaCa is often diagnosed during late metastatic stages. Besides surgical resection, no other treatment appears to be effective during earlier stages of the disease. Exosomes are related to a class of nanovesicles coated by a bilayer lipid membrane and enriched in protein, nucleic acid, and lipid contents. They are widely present in human body fluids, including blood, saliva, and pancreatic duct fluid, with functions in signal transduction and material transport. A large number of studies have suggested for a crucial role for exosomes in PaCa, which may be utilized to improve its future diagnosis and treatment, but the underlying molecular mechanisms as well as their potential clinical applications are largely unknown. By collecting and analyzing the most up-to-date literature, here we summarize the current progress of the clinical applications related to exosomes in PaCa. Therefore, we presently provide some rationale for the potential value of exosomes in PaCa, thereby promoting putative applications in targeted PaCa treatment.

Negative feedback loop of ERK/CREB/miR-212-3p inhibits HBeAg-induced macrophage activation

The activation of liver macrophages is closely related to liver injury after HBV infection. Our previous results demonstrated that HBeAg played a key role in inducing macrophage activation. As we all know, miRNAs are involved in the regulation of multiple immune cell functions. Meanwhile, we have shown that miR‐155 positively regulates HBeAg‐induced macrophage activation and accelerates liver injury. Subsequently, based on our previous miRNA sequencing results, we further evaluated the role of miR‐212‐3p called ‘neurimmiR’ in HBeAg‐induced macrophages in this study. First, miR‐212‐3p expression was significantly elevated in HBeAg‐treated macrophages. Meanwhile, we found up‐regulation of miR‐212‐3p significantly decreased the production of cytokines, whereas knockdown of miR‐212‐3p held the opposite effect by gains and losses of function. Mechanically, although MAPK signal pathway, including ERK, JNK and p38, was activated in HBeAg‐induced macrophages, only ERK promoted the expression of miR‐212‐3p via transcription factor CREB, which was able to bind to the promoter of miR‐212‐3p verified by ChIP assay. Moreover, we further indicated that up‐regulated miR‐212‐3p inhibited HBeAg‐induced inflammatory cytokine production through targeting MAPK1. In conclusion, miR‐212‐3p was augmented in HBeAg‐stimulated macrophages via ERK/CREB signal pathway and the elevated miR‐212‐3p suppressed inflammatory cytokine production induced by HBeAg through targeting MAPK1.

miR-212-5p exerts tumor promoter function by regulating the Id3/PI3K/Akt axis in lung adenocarcinoma cells

microRNAs may function as oncogenes or tumor suppressor genes that play crucial roles in human carcinogenesis and cancer development. Growing evidence revealed that the tumor suppressor Id3 is involved in tumor progression, carcinogenesis, and the tumor microenvironment. We identified miR-212-5p as a negative posttranscriptional modulator of Id3. Dual luciferase reporter assay was used to verify that Id3 is a direct target gene of miR-212-5p. Id3 was lowly expressed and miR-212-5p was highly expressed in non-small-cell lung cancer (NSCLC) tissues and cells. In addition, we found that NSCLC patients having a higher level of miR-212-5p expression had a shorter survival time. Besides this, miR-212-5p could directly target Id3 and reduce its expression. miR-212-5p overexpression significantly accelerated cell proliferation, migration, and invasion by reversing the effects of Id3. Id3 overexpression by silencing miR-212-5p expression suppressed phosphatidylinositol 3 kinase (PI3K)/Akt activity and consequently promoted apoptosis and inhibited cell proliferation in lung cancer cells. Consistent with the in vitro results, a xenograft mouse model was used to validate the fact that miR-212-5p could promote tumorigenesis by targeting Id3 and activate the PI3K/Akt pathway in vivo as well. Taken together, the present results indicated that miR-212-5p may be involved in progression of NSCLC through the PI3K/Akt signaling pathway by targeting Id3.

Elevated expression of exosomal microRNA-21 as a potential biomarker for the early diagnosis of pancreatic cancer using a tethered cationic lipoplex nanoparticle biochip

Pancreatic cancer (PC) has a poor prognosis due to the lack of effective molecular biomarkers for early diagnosis. Recent studies have investigated the use of exosomal microRNAs (exmiRs) as diagnostic biomarkers in cancer. The present study examined exmiR-21, exmiR-10b and exmiR-212-3p expression in patients with PC and healthy individuals. The expression levels of exmiR-21, exmiR-10b and exmiR-212-3p were examined in the peripheral blood plasma of 36 patients with PC and 65 healthy controls, using tethered cationic lipoplex nanoparticle biochip. The levels of exmiR-21 in the plasma of 34 mice were also evaluated. The expression levels of exmiR-21 and exmiR-10b were significantly greater in patients with PC compared with the control group. The receiver operating characteristic (ROC) analysis indicated that exmiR-21 had better diagnostic performance (P=0.0003; AUC, 0.7171) compared with the other two exmiRs. The diagnostic value of exmiR-21 improved when combined with exmiR-10b (P<0.0001; AUC, 0.791). Furthermore, exmiR-21 was capable of distinguishing patients with early-stage PC from controls and advanced-stage PC (P<0.05, early stage vs. healthy; P<0.001, early stage vs. advanced stage). The results of the present study revealed that the plasma levels of exmiR-21 and exmiR-10b were upregulated in patients with PC. The ROC analyses indicated that exmiR-21 had the best diagnostic performance among the three exmiRs. Furthermore, exmiR-21 was capable of discriminating patients with early-stage PC from healthy controls. These findings indicate the potential of determining the expression of exmiR-21 from serum using a tethered cationic lipoplex nanoparticle biochip as a novel non-invasive strategy for the early diagnosis of PC.

The functions and targets of miR-212 as a potential biomarker of cancer diagnosis and therapy

Cancer is a major health problem worldwide. An increasing number of researchers are studying the diagnosis, therapy and mechanisms underlying the development and progression of cancer. The study of noncoding RNA has attracted a lot of attention in recent years. It was found that frequent alterations of miRNA expression not only have various functions in cancer but also that miRNAs can act as clinical markers of diagnosis, stage and progression of cancer. MiR-212 is an important example of miRNAs involved in cancer. According to recent studies, miR-212 may serve as an oncogene or tumour suppressor by influencing different targets or pathways during the oncogenesis and the development and metastasis of cancer. Its deregulation may serve as a marker for the diagnosis or prognosis of cancer. In addition, it was recently reported that miR-212 was related to the sensitivity or resistance of cancer cells to chemotherapy or radiotherapy. Here, we summarize the current understanding of miR-212 functions in cancer by describing the relevant signalling pathways and targets. The role of miR-212 as a biomarker and its therapeutic potential in cancer is also described. The aim of this review was to identify new methods for the diagnosis and treatment of human cancers.

MicroRNA‑766 inhibits the malignant biological behaviours of pancreatic ductal adenocarcinoma by directly targeting ETS1

Increasing evidence indicates that numerous microRNAs (miRNAs) are altered in pancreatic ductal adenocarcinoma (PDAC), and their alterations significantly influence the malignant behaviour of PDAC. Therefore, identifying miRNAs associated with PDAC and their biological roles in the disease may provide promising therapeutic opportunities. Alteration of the expression of miRNA‑766 (miR‑766) has been previously reported in several types of human malignancy. However, to the best of our knowledge, whether miR‑766 exhibits different expression patterns in PDAC and its underlying functions in the progression of PDAC remain to be elucidated. In the present study, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was used to detect miR‑766 expression levels in PDAC tissues and cell lines. The effects of miR‑766 upregulation on PDAC cell proliferation and invasion were evaluated using MTT and invasion assays, respectively. The mechanisms underlying the role of miR‑766 in PDAC cells were explored using bioinformatics analysis, luciferase reporter assay, RT‑qPCR and western blot analysis. It was found that miR‑766 was significantly downregulated in PDAC tissues and cell lines. The detailed roles of miR‑766 in the progression of PDAC were characterised using Panc‑1 and Aspc‑1 cell lines. The results revealed that the upregulation of miR‑766 restricted the proliferation and invasion of PDAC cells. Through a series of experiments, it was found that E26 transformation specific‑1 (ETS1) was a direct target of miR‑766 in PDAC cells. Furthermore, ETS1 knockdown simulated the inhibitory effects of the overexpression of miR‑766 on PDAC cells, whereas the effects of miR‑766 restoration on the PDAC cells were reversed by overexpressing ETS1. In conclusion, the findings of the present study demonstrate that miR‑766 offers potential as a therapeutic target for patients with PDAC.

Delivery of miR-212 by chimeric peptide-condensed supramolecular nanoparticles enhances the sensitivity of pancreatic ductal adenocarcinoma to doxorubicin

Pancreatic ductal adenocarcinoma (PDAC) is a destructive cancer with poor prognosis. Both novel therapeutic targets and approaches are needed to improve the overall survival of PDAC patients. MicroRNA-212 (miR-212) has been reported as a tumor suppressor in multiple cancers, but its definitive role and exact mechanism in the progression of pancreatic cancer is unclear. In this study, we developed a new chimeric peptide (PL-1) composed of plectin-1-targeted PDAC-specific and arginine-rich RNA-binding motifs which could condense miRNA to self-assemble supramolecular nanoparticles. These nanoparticles could deliver miR-212 into PDAC cells specifically and efficiently which also showed good stability in RNase and serum. Moreover, we demonstrated that PL-1/miR-212 nanoparticles could dramatically enhance the chemotherapeutic effect of doxorubicin for PDAC both in vitro and in vivo. In terms of mechanism, combined miR-212 intervention by PL-1/miR-212 nanoparticles resulted in obvious decrease of USP9X expression (ubiquitin specific peptidase 9, X-linked, USP9X) and eventually enhanced the doxorubicin induced apoptosis and autophagy of PDAC cells. These findings provide a new promising anti-cancer strategy via PL-1/miR-212 nanoparticles and identify miR-212/USP9X as a new potential target for future systemic therapy against human PDAC.

miR-212 regulated by HIF-1α promotes the progression of pancreatic cancer

MicroRNA-212 (miR-212) is dysregulated in numerous tissues and cancer types and serves a role in the progression of human cancer. However, the function and mechanism of miR-212 in the development of pancreatic ductal adenocarcinoma (PDAC) remain unknown, particularly in a hypoxic microenvironment. In the present study, miR-212 expression was observed to be significantly upregulated in PDAC tissues compared with normal tissues. Clinical data analysis indicated that miR-212 was positively associated with a large tumor size, Tumor-Node-Metastasis stage, lymph node metastasis and vessel invasion, and influenced the overall survival time. Notably, there was a positive association between the expression of hypoxia-inducible factor-1α (HIF-1α) and miR-212 in vivo and in vitro in hypoxic conditions. Mechanistically, HIF-1α bound directly to a hypoxia response element in the miR-212 promoter region and activated miR-212 expression in PDAC cells. Collectively, these results demonstrated that HIF-1α positively regulated miR-212 expression and resulted in PDAC progression.

MicroRNA-212 Targets Mitogen-Activated Protein Kinase 1 to Inhibit Proliferation and Invasion of Prostate Cancer Cells

Prostate cancer (PCa) is the second most commonly diagnosed malignancy and the fifth leading cause of cancer-related deaths in males worldwide. MicroRNAs (miRNAs) may serve as important regulators in PCa occurrence and development. Therefore, understanding the expression and functions of PCa-related miRNAs may be beneficial for the identification of novel therapeutic methods for patients with PCa. In this study, miRNA-212 (miR-212) was evidently downregulated in PCa tissues and several PCa cell lines. Functional assays showed that the resumption of miR-212 expression attenuated cell proliferation and invasion and increased the apoptosis of PCa. In addition, mitogen-activated protein kinase 1 (MAPK1), a well-known oncogene, was identified as a novel target of miR-212 in PCa, as confirmed by bioinformatics, luciferase reporter assay, qRT-PCR, and Western blot analysis. Furthermore, MAPK1 expression was upregulated in PCa tissues and inversely correlated with miR-212 expression. Rescue experiments also demonstrated that restored MAPK1 expression reversed the tumor-suppressing effects of miR-212 on PCa cell proliferation, invasion, and apoptosis. In conclusion, miR-212 may exert tumor-suppressing roles in PCa by regulating MAPK1 and could be a novel therapeutic target for treatment of patients with this malignancy.