miR-188-5p Suppresses Gastric Cancer Cell Proliferation and Invasion via Targeting ZFP91

LncRNA EBLN3P Accelerates Cell Proliferation and Invasion of Colon Cancer through Modulating the miR-519d-3p/ZFP91 Axis

Purpose: The study aims to explore the roles and underlying mechanisms of long noncoding RNAs endogenous bornavirus-like nucleoprotein (lncRNA EBLN3P) in colon cancer, emphasizing the potential impact of these insights on advancing colon cancer treatment strategies. By shedding light on lncRNA EBLN3P's involvement, this research could contribute to the development of novel therapeutic approaches, enhancing the efficacy of interventions for colon cancer patients. Methods: We employed quantitative reverse transcription polymerase chain reaction to assess the levels of lncRNA EBLN3P, zinc finger protein (ZFP91), and miR-519d-3p, alongside CCK-8 and EdU assays for cell proliferation, flow cytometry for apoptosis, and Transwell and wound healing assays for migration and invasion. The in vivo function of lncRNA EBLN3P was investigated through a xenograft model, and protein levels were evaluated via Western blot analysis. Results: LncRNA EBLN3P was found to be upregulated in colon cancer tissues and cells, promoting cell proliferation and metastasis while inhibiting apoptosis. Downregulation of lncRNA EBLN3P reduced tumor size, volume, and weight in a mouse model. MiR-519d-3p, which negatively interacts with lncRNA EBLN3P, was found to be downregulated in colon cancer tissues and cell lines. Its upregulation hindered cancer cell proliferation and metastasis while enhancing apoptosis. ZFP91, a binding partner of miR-519d-3p, was upregulated in colon cancer and inversely related to miR-519d-3p levels. Rescue experiments indicated that the effects of lncRNA EBLN3P silencing could be reversed by miR-519d-3p suppression, but were mitigated by ZFP91 downregulation. Conclusion: LncRNA EBLN3P facilitates colon cancer progression via the miR-519d-3p/ZFP91 axis, presenting a novel understanding of lncRNA EBLN3P's role and offering potential therapeutic insights for colon cancer treatment. This study fills a critical gap by linking lncRNA EBLN3P with the miR-519d-3p/ZFP91 axis in the context of colon cancer, thereby broadening our understanding of the molecular mechanisms underlying colon cancer progression.

SALL4 in gastrointestinal tract cancers: upstream and downstream regulatory mechanisms

Effective therapeutic targets and early diagnosis are major challenges in the treatment of gastrointestinal tract (GIT) cancers. SALL4 is a well-known transcription factor that is involved in organogenesis during embryonic development. Previous studies have revealed that SALL4 regulates cell proliferation, survival, and migration and maintains stem cell function in mature cells. Additionally, SALL4 overexpression is associated with tumorigenesis. Despite its characterization as a biomarker in various cancers, the role of SALL4 in GIT cancers and the underlying mechanisms are unclear. We describe the functions of SALL4 in GIT cancers and discuss its upstream/downstream genes and pathways associated with each cancer. We also consider the possibility of targeting these genes or pathways as potential therapeutic options for GIT cancers.

Molecular Insight into Gastric Cancer Invasion-Current Status and Future Directions

Gastric cancer (GC) is one of the most common malignancies worldwide. There has been no efficient therapy for stage IV GC patients due to this disease's heterogeneity and dissemination ability. Despite the rapid advancement of molecular targeted therapies, such as HER2 and immune checkpoint inhibitors, survival of GC patients is still unsatisfactory because the understanding of the mechanism of GC progression is still incomplete. Invasion is the most important feature of GC metastasis, which causes poor mortality in patients. Recently, genomic research has critically deepened our knowledge of which gene products are dysregulated in invasive GC. Furthermore, the study of the interaction of GC cells with the tumor microenvironment has emerged as a principal subject in driving invasion and metastasis. These results are expected to provide a profound knowledge of how biological molecules are implicated in GC development. This review summarizes the advances in our current understanding of the molecular mechanism of GC invasion. We also highlight the future directions of the invasion therapeutics of GC. Compared to conventional therapy using protease or molecular inhibitors alone, multi-therapy targeting invasion plasticity may seem to be an assuring direction for the progression of novel strategies.

miR-188-5p silencing improves cerebral ischemia/reperfusion injury by targeting Lin28a

This report aimed to explore whether miR-188-5p regulated the pathological regulatory network of cerebral ischemia/reperfusion (I/R) injury. We simulated the cerebral I/R injury model with MACO/R and OGD/R treatments. Neuronal viability and apoptosis were assessed. The contents of miR-188-5p and Lin 28a were evaluated. The abundances of apoptosis-related proteins (Bax, Bcl-2, and cleaved caspase-3) and pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) were measured. The interaction of miR-188-5p and Lin28a was confirmed. Lin28a silencing was supplemented to determine the delicate regulation of miR-188-5p. We revealed that miR-188-5p was upregulated and Lin28a was downregulated in I/R rats and OGD/R-induced cells. miR-188-5p silencing remarkably reduced the cerebral infarction volume, neurobehavioral score, brain edema, and Evans blue leakage. miR-188-5p silencing enhanced neuronal viability and alleviated apoptosis. The abundance of Bax and cleaved caspase-3 was reduced by miR-188-5p silencing, while Bcl-2 was augmented. miR-188-5p silencing impeded the contents of TNF-α, IL-1β, and IL-6. miR-188-5p interacted with Lin28a and negatively regulated its expression. Interestingly, extra Lin28a silencing reversed apoptosis and the content of inflammatory cytokines. Our studies confirmed that miR-188-5p silencing alleviated neuronal apoptosis and inflammation by mediating the expression of Lin28a. The crosstalk of miR-188-5p and Lin28a offered a different direction for ischemic stroke therapy.

m6A-related lncRNAs predict prognosis and indicate cell cycle in gastric cancer

Background: N6-methyladenosine (m6A) modification is a common epigenetic methylation modification of RNA, which plays an important role in gastric carcinogenesis and progression by regulating long non-coding RNA (lncRNA). This study is aimed to investigate the potential prognostic signatures of m6A -related lncRNAs in STAD. Methods: The m6A-related lncRNAs with the most significant impact on gastric cancer prognosis in the TCGA database were identified by bioinformatics and machine learning methods. The m6A-related lncRNA prognostic model (m6A-LPS) and nomogram was constructed by Cox regression analysis with the minimum absolute contraction and selection operator (LASSO) algorithm. The functional enrichment analysis of m6A-related lncRNAs was also investigated. The miRTarBase, miRDB and TargetScan databases were utilized to establish a prognosis-related network of competing endogenous RNA (ceRNA) by bioinformatics methods. The correlation of AL391152.1 expressions and cell cycle were experimentally testified by qRT-PCR and flow cytometry. Results: In total, 697 lncRNAs that were identified as m6A-related lncRNAs in GC samples. The survival analysis showed that 18 lncRNAs demonstrated prognostic values. A risk model with 11 lncRNAs was established by Lasso Cox regression, and can predict the prognosis of GC patients. Cox regression analysis and ROC curve indicated that this lncRNA prediction model was an independent risk factor for survival rates. Functional enrichment analysis and ceRNA network revealed that the nomogram was notably associated with cell cycle. qRT-PCR and flow cytometry revealed that downregulation of GC m6A-related lncRNA AL391152.1 could decrease cyclins expression in SGC7901 cells. Conclusion: A m6A-related lncRNAs prognostic model was established in this study, which can be applied to predict prognosis and cell cycle in gastric cancer.

miR-188-5p and Host MALAT1 Regulate RBE Cell Migration, Invasion, and Apoptosis via Up-regulating PSMD10 in Cholangiocarcinoma

The study is designed to explore the regulatory network that MALAT1 competitively binds with miR-188-5p to up-regulate PSMD10 to facilitate cholangiocarcinoma cell migration and invasion and suppress apoptosis. qRT-PCR and fluorescence in situ hybridization (FISH) were used to examine the expression and positive signal of MALAT1 and miR-188-5p in cholangiocarcinoma tissues and HIBEC, HCCC-9810, RBE, and QBC939 cells. Western blot, qRT-PCR, and immunohistochemistry were selected to detect PSMD10 expression in cholangiocarcinoma tissues and cell lines. Dual luciferase reporter gene assay was adopted to verify that miR-188-5p targeted MALAT1 and PSMD10. qRT-PCR, pull down, and western blot were used to examine the regulation of MALAT1-miR-188-5p-PSMD10 axis. Transwell, wound healing assay, and Tunel cell apoptosis were adopted to respectively detect the regulatory abilities of MALAT1-miR-188-5p-PSMD10 axis on cell invasion, migration, and apoptosis. Western blot was used to detect the regulation mechanism of MALAT1 on Bax, Bcl-2, and caspase-3 proteins. Nude mice subcutaneous xenograft model of cholangiocarcinoma was established to examine the impacts of MALAT1 on subcutaneous tumor growth. Immunohistochemistry was adopted to examine the positive indicator of Ki67 antibodies and SMD10 antibodies in each group. MALAT1 and PSMD10 were highly expressed in cholangiocarcinoma tissues and cell lines, while miR-188-5p was lowly expressed. MALAT1 could competitively bind to miR-188-5p, and miR-188-5p could negatively regulate PSMD10. MALAT1, In-miR-188-5p, and PSMD10 could facilitate cell invasion and migration and inhibit apoptosis, while siMALAT1, miR-188-5p, and siPSMD10 produced an opposite result. MALAT1-miR-188-5p-PSMD10 axis could promote RBE cell invasion and migration and inhibit apoptosis, whereas siMALAT1-In-miR-188-5p-siPSMD10 axis showed an opposite result. On the other hand, it was verified that up-regulation/down-regulation of MALAT1 can inhibit/promote Bax and caspase-3 proteins and promote/inhibit the expression of Bcl-2 protein. MALAT1 could facilitate subcutaneous tumor growth and enhance cell proliferation and positive signal of PSMD10, while miR-188-5p worked in an opposite direction. MALAT1 competitively binds to miR-188-5p to up-regulate mRNA translation and protein expression of PSMD10, thereby facilitating cholangiocarcinoma cell invasion and migration and inhibiting its apoptosis. However, interfering MALAT1-miR-188-5p-PSMD10 axis could inhibit the occurrence and development of cholangiocarcinoma.

The miR-3648/FRAT1-FRAT2/c-Myc negative feedback loop modulates the metastasis and invasion of gastric cancer cells

Although the abnormal expression of miRNAs in cancer cells is a widely accepted phenomenon, the molecular mechanisms underlying miR-3648 progression and metastasis in gastric cancer (GC) remain unclear. miR-3648 expression is downregulated and its ectopic expression in GC cells significantly suppressed cell proliferation and metastasis. Mechanistic analyses indicated that miR-3648 directly targets FRAT1 or FRAT2 and inhibits FRAT1- or FRAT2-mediated invasion and motility in vitro and in vivo. Moreover, FRAT1 physically interacted with FRAT2. Furthermore, FRAT1 overexpression promoted GC cell invasion, whereas siRNA-mediated repression of FRAT2 in FRAT1-overexpressing GC cells reversed its invasive potential. Besides, miR-3648 inactivated the Wnt/β-catenin signalling pathway by downregulating FRAT1 and FRAT2 in GC. Interestingly, c-Myc, a downstream effector of Wnt/β-catenin signalling, was also downregulated by miR-3648 overexpression. In turn, c-Myc negatively regulated miR-3648 expression by binding to the miR-3648 promoter. In addition, miR-3648 expression levels were negatively correlated with c-Myc, FRAT1, and FRAT2 expression in fresh gastric samples. Our studies suggest that miR-3648 acts as a tumour-suppressive miRNA and that the miR-3648/FRAT1-FRAT2/c-Myc negative feedback loop could be a critical regulator of GC progression.

Exosome miRNA Expression in Umbilical Cord Blood of High-Parity Sows Regulates Their Reproductive Potential

The objective of modern pig breeding is to improve the genetic reproduction performance potential of sows, including the litter size and weight of piglets. During the gestation period, the umbilical cord facilitates placenta−fetal communication; thus, it plays an indispensable role in intrauterine embryonic development and fitness. Herein, we analyzed the molecular mechanism in declining reproductive potential in high-parity sows by assessing the changes in the umbilical cord blood. Firstly, we analyzed the reproductive characteristics data of sows, followed by histological analysis of the umbilical cord phenotype. Next, we evaluated the effect of umbilical cord blood exosomes (UCB-EXO) on angiogenesis. Finally, the miRNA expression in UCB-EXO from high-parity sows with poor reproductive performance (OS) and multiparous sows with excellent reproductive performance (MS) was assessed. Overall, the best reproductive performance was at parity 3−7, gradually decreasing after parity 8 and angiogenesis was repressed in OS. However, exosomes derived from MS (Exo-MS) exhibited pro-angiogenesis properties but were diminished in exosomes derived from OS (Exo-OS). Additionally, the angiogenesis of sows was significantly decreased, increasing the risk of disease with the increase in parity, greatly limiting the reproductive potential of the sows. At the same time, miR-188-5p expression in Exo-OS was significantly higher than in Exo-MS (p < 0.01), implying that it may play an important role in regulating the lifespan and reproductive potential of sows. These findings demonstrated that miRNAs in UCB-EXO play a central role in intrauterine development. Further, the findings suggest novel insights on reproductive potential, which provide a reference for increasing the sow reproductive efficiency.

LncRNA GNAS-AS1 knockdown inhibits keloid cells growth by mediating the miR-188-5p/RUNX2 axis

Keloid is a common dermis tumor, occurring repeatedly, affecting the quality of patients' life. Long non-coding RNAs (lncRNAs) have crucial regulatory capacities in skin scarring formation and subsequent scar carcinogenesis. The intention of this study was to investigate the mechanism and function of GNAS antisense-1 (GNAS-AS1) in keloids. Clinical samples were collected to evaluate the expression of GNAS-AS1, RUNX2, and miR-188-5p by qRT-PCR. The proliferation, migration, and invasion of HKF cells were detected by CCK-8, wound healing, and Transwell assays. The expression levels of mRNA and protein were examined through qRT-PCR and Western blot assay. Luciferase reporter assay was used to identify the binding relationship among GNAS-AS1, miR-188-5p, and Runt-related transcription factor 2 (RUNX2). GNAS-AS1 and RUNX2 expressions were remarkably enhanced, and miR-188-5p expression was decreased in keloid clinical tissues and HKF cells. GNAS-AS1 overexpression promoted cells proliferation, migration, and invasion, while GNAS-AS1 knockdown had the opposite trend. Furthermore, overexpression of GNAS-AS1 reversed the inhibitory effect of 5-FU on cell proliferation, migration, and invasion. MiR-188-5p inhibition or RUNX2 overexpression could enhance the proliferation, migration, and invasion of HKF cells. GNAS-AS1 targeted miR-188-5p to regulate RUNX2 expression. In addition, the inhibition effects of GNAS-AS1 knockdown on HKF cells could be reversed by inhibition of miR-188-5p or overexpression of RUNX2, while RUNX2 overexpression eliminated the suppressive efficaciousness of miR-188-5p mimics on HKF cells growth. GNAS-AS1 knockdown could regulate the miR-188-5p/RUNX2 signaling axis to inhibit the growth and migration in keloid cells. It is suggested that GNAS-AS1 may become a new target for the prevention and treatment of keloid.

ETV5-mediated upregulation of lncRNA CTBP1-DT as a ceRNA facilitates HGSOC progression by regulating miR-188-5p/MAP3K3 axis

High-grade serous ovarian cancer (HGSOC) is a common and lethal cancer of the female reproductive system. Long non-coding RNAs (lncRNAs) are aberrantly expressed in various cancers and play crucial roles in tumour progression. However, their function and molecular mechanism in HGSOC remain largely unknown. Based on public databases and bioinformatics analyses, the overexpression of lncRNA CTBP1-DT in HGSOC tissues was detected and validated in a cohort of HGSOC tissues. High expression of lncRNA CTBP1-DT was associated with poor prognosis and was an independent risk factor for survival. Overexpression of lncRNA CTBP1-DT promoted malignant biological behaviour of HGSOC cells, whereas its depletion induced growth arrest of HGSOC cells by vitro and in vivo assays. Mechanistically, lncRNA CTBP1-DT could competitively bind to miR-188-5p to protect MAP3K3 from degradation. Moreover, our results revealed that ETV5 could specifically interact with the promoter of lncRNA CTBP1-DT and activate its transcription. Collectively, these results reveal a novel ETV5/lncRNA CTBP1-DT/miR-188-5p/MAP3K3 pathway for HGSOC progression and suggest that lncRNA CTBP1-DT might be a potential biomarker and therapeutic target for HGSOC.

Endoplasmic reticulum stress promotes sorafenib resistance via miR-188-5p/hnRNPA2B1-mediated upregulation of PKM2 in hepatocellular carcinoma

Emerging evidence has shown that endoplasmic reticulum (ER) stress promotes sorafenib resistance in hepatocellular carcinoma (HCC). However, the underlying mechanisms are poorly understood. The purpose of this study was to explore the mechanism by which ER stress promotes sorafenib resistance in HCC. We found that pyruvate kinase isoform M2 (PKM2) was highly expressed in human HCC tissues and co-related with worse clinicopathologic features and overall survival. Activation of ER stress positively correlated with PKM2 expression both in HCC tissue samples and tunicamycin (TM)-induced HCC cell lines. PKM2 knockdown increased sorafenib-induced apoptosis and decreased the ability of colony formation, while upregulation of PKM2 reverses this phenomenon. Furthermore, high-throughput sequencing identified that activation of ER stress significantly downregulated the expression of miR-188-5p in HCC cells. According to bioinformatics analysis and dual-luciferase assays, we further confirmed that hnRNPA2B1 is the target gene of miR-188-5p. Downregulating the expression of hnRNPA2B1 with siRNA could decrease the expression of PKM2 and enhance sorafenib-induced apoptosis in HepG2 cells. Our study demonstrated that ER stress could promote sorafenib resistance through upregulating PKM2 via miR-188-5p/hnRNPA2B1. Therefore, targeting the miR-188-5p/hnRNPA2B1/PKM2 pathway and ER stress may prove instrumental in overcoming sorafenib resistance in HCC treatment.

Potentiated lung adenocarcinoma (LUAD) cell growth, migration and invasion by lncRNA DARS-AS1 via miR-188-5p/ KLF12 axis

Lung adenocarcinoma (LUAD) is the most common histological type of non-small cell lung cancer (NSCLC). Due to the nonspecific early symptoms, the majority of the diagnosed LUAD patients are in the middle and late stages, with multiple metastases, and have missed the optimal period for treatment. Current studies have reported lncRNA DARS-AS1 as a cancer-promoting gene that expedites tumorigenesis. This is the first study demonstrating that DARS-AS1 is involved in the mediating process of LUAD. Cell functional experiments revealed that lncRNA DARS-AS1 participated in enhancing LUAD proliferation, invasion, and migration by inhibiting miR-188-5p. The investigation on DARS-AS1/miR-188-5p led to the discovery of KLF12 as a downstream target of miR-188-5p, and the regulatory pathway was established as DARS-AS1/miR-188-5p/KLF12. According to western blot results, DARS-AS1 promoted LUAD cell growth, migration, and invasion via stimulation of the PI3K/AKT pathway, activating the EMT process, and up-regulating the CyclinD1 and Bcl-2 proteins. This was the first report on the DARS-AS1/miR-188-5p/KLF12 axis and offered a novel strategy for early diagnosis, a new therapeutic method, and an improved prognosis for LUAD.

Arf6 regulates energy metabolism in neutrophils

The small GTPase Arf6 regulates many cellular processes, including cytoskeletal remodeling, receptor endocytosis, and pathogen phagocytosis. Arf6 silencing in neutrophil (PMN)-like cells is well-known to inhibit chemotactic peptide-mediated activation of phospholipase D, the oxidative burst, and β2 integrin-dependent adhesion. In conditional knockout (cKO) mice, the migration to inflammatory sites of Arf6-deficient PMNs was diminished and associated with reduced cell surface expression of β2 integrins. In this study we assessed the impact of Arf6 depletion on the functions and gene expression profile of PMNs isolated from the mouse air pouch. Numerous genes involved in response to oxygen levels, erythrocyte and myeloid differentiation, macrophage chemotaxis, response to chemicals, apoptosis, RNA destabilization, endosome organization, and vesicle transport were differentially expressed in PMNs cKO for Arf6. Lpar6 and Lacc-1 were the most up-regulated and down-regulated genes, respectively. The deletion of Arf6 also decreased Lacc-1 protein level in PMNs, and silencing of Arf6 in THP-1 monocytic cells delayed LPS-mediated Lacc-1 expression. We report that fMLP or zymosan-induced glycolysis and oxygen consumption rate were both decreased in air pouch PMNs but not in bone marrow PMNs of Arf6 cKO mice. Reduced oxygen consumption correlated with a decrease in superoxide and ROS production. Deletion of Arf6 in PMNs also reduced phagocytosis and interfered with apoptosis. The data suggest that Arf6 regulates energy metabolism, which may contribute to impaired phagocytosis, ROS production, and apoptosis in PMN-Arf6 cKO. This study provides new information on the functions and the inflammatory pathways influenced by Arf6 in PMNs.

MiR-188-3p and miR-133b Suppress Cell Proliferation in Human Hepatocellular Carcinoma via Post-Transcriptional Suppression of NDRG1

Background:

Previous studies reported that N-myc downstream-regulated gene 1 (NDRG1) was upregulated in various cancer tissues and decreased expression of miR-188-3p and miR-133b could suppress cell proliferation, metastasis, and invasion and induce apoptosis of cancer cells. However, the molecular mechanism of NRDG1 involved in hepatocellular carcinoma (HCC) tumorigenesis is still unknown.

Methods:

The expressions of miR-188-3p, miR-133b, and NRDG1 in HCC tissues and cells were quantified by qRT-PCR and Western blot. MTT assay and transwell invasion assay were performed to evaluate cell growth and cell migration, respectively. Luciferase reporter assay were performed to determine whether miR-188-3p and miR-133b could directly bind to NRDG1 in HCC cells.

Results:

The results showed that NRDG1 was upregulated and these 2 microRNAs were downregulated in HCC tissues. NRDG1 was negatively correlated with miR-188-3p and miR-133b in HCC tissues. MiR-188-3p and miR-133b were demonstrated to directly bind to 3′UTR of NRDG1 and inhibit its expression. Upregulation of miR-188-3p and miR-133b reduced NRDG1 expression in hepatocellular carcinoma cell lines, which consequently inhibited cell growth and cell migration.

Conclusions:

Our finding suggested that miR-188-3p and miR-133b exert a suppressive effect on hepatocellular carcinoma proliferation, invasion, and migration through downregulation of NDRG1.

Validation of MicroRNA-188-5p Inhibition Power on Tumor Cell Proliferation in Papillary Thyroid Carcinoma

Given the crucial role of microRNAs in the cellular proliferation of various types of cancers, we aimed to analyze the expression and function of a cellular proliferation-associated miR-188-5p in papillary thyroid carcinoma (PTC). Here we demonstrate that miR-188-5p is downregulated in PTC tumor tissues compared with the associated noncancerous tissues. We also validate that the miR-188-5p overexpression suppressed the PTC cancer cell proliferation. In addition, fibroblast growth factor 5 (FGF5) is observed to be downregulated in the PTC tumor tissues compared with the associated noncancerous tissues. Subsequently, FGF5 is identified as the direct functional target of miR-188-5p. Moreover, the silencing of FGF5 was found to inhibit PTC cell proliferation, which is the same pattern as miR-188-5p overexpression. These results suggest that miR-188-5p-associated silencing of FGF5 inhibits tumor cell proliferation in PTC. It also highlights the importance of further evaluating miR-188-5p as a potential biomarker and therapy target in PTC.

Circ-PRMT5 enhances the proliferation, migration and glycolysis of hepatoma cells by targeting miR-188-5p/HK2 axis

INTRODUCTION AND OBJECTIVES

Circular RNA (circRNA) has been demonstrated as a critical regulator in human cancer, including hepatocellular carcinoma (HCC). Nevertheless, the role of circ-PRMT5 in HCC remains largely unknown.

PATIENTS OR MATERIALS AND METHODS

The real-time quantitative polymerase chain reaction (RT-qPCR) was performed to assess the expression levels of circ-PRMT5, miR-188-5p and anti-Hexokinase II (HK2) in HCC tissues and cells. The cell proliferation, migration and glycolysis were determined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT), transwell migration assay, and indicated kits, respectively. The interaction relationship between miR-188-5p and circ-PRMT5 or HK2 was analyzed by the bioinformatics database, dual-luciferase reporter assay, and RNA immunoprecipitation (RIP) assay. The western blot assay was used to analyze the expression level of HK2. The functional role of circ-PRMT5 in vivo was assessed by a xenograft experiment.

RESULTS

Circ-PRMT5 was elevated in HCC tissues and cells than matched control groups. Furthermore, loss-of-functional experiments revealed that the silencing of circ-PRMT5 could repress proliferation, migration, glycolysis in vitro and tumor growth in vivo. Moreover, we also confirmed that overexpression of circ-PRMT5 abolished the effects on HCC cells induced by upregulating miR-188-5p. In addition, overexpression of miR-188-5p could repress the development of HCC. More importantly, HK2 was a target gene of miR-188-5p, and miR-188-5p regulated proliferation, migration, glycolysis of HCC cells by specifically binding to HK2. Mechanistically, circ-PRMT5 could act as a sponge of miR-188-5p to regulate the expression of HK2.

CONCLUSION

In summary, circ-PRMT5 might play a key role in proliferation, migration, glycolysis of HCC cells via miR-188-5p/HK2 axis, which indicated that circ-PRMT5 might be a potential therapeutic target for HCC treatment.

MicroRNA miR-188-5p as a mediator of long non-coding RNA MALAT1 regulates cell proliferation and apoptosis in multiple myeloma

Multiple myeloma (MM), a malignancy of plasma cells mainly derived from the bone marrow, has remained incurable generally. LncRNA MALAT1 has been reported to be upregulated in the MM cells and knockdown of MALAT1 inhibited MM cell cycle progression and enhanced cell apoptosis. Online target prediction showed that two target sites for MALAT1 existed in miR-188-5p, which has been identified as a tumor suppressor in other types of cancers. However, the role of miR-188-5p in the MM and whether miR-188-5p mediates the MM tumor progression regulated by MALAT1 are still unknown. Herein, four main MM cell lines were adopted to investigate the effects of miR-188-5p on cell proliferation and apoptosis via transfection with miR-188-5p mimic/inhibitor and co-transfection with miR-188-5p inhibitor and MALAT1-shRNA plasmids. Xenograft tumor model was also established to study these effects in vivo. Overexpression of miR-188-5p inhibited cell viability, cell proliferation as well as tumor growth and arrested cell cycle at G1 to S transition, but miR-188-5p knockdown showed opposite effects on the MM cells in vitro and in vivo. Moreover, MALAT1 was shown to be inversely correlated with miR-188-5p expression through direct binding to miR-188-5p, and in turn, miR-188-5p could mediate the MM cell proliferation and apoptosis regulated by MALAT1. These findings indicate that miR-188-5p serves as a tumor suppressor in the progression of the MM and is directly involved in MM cell proliferation and apoptosis regulated by MALAT1, which may provide a potential therapeutic target or prognostic indictor for MM clinical treatment.

miR-188-5p promotes oxaliplatin resistance by targeting RASA1 in colon cancer cells

The efficacy of chemotherapy for colon cancer is limited due to the development of chemoresistance. MicroRNA (miR)-188-5p is downregulated in various types of cancer. The aim of the present study was to explore the molecular role of miR-188 in oxaliplatin (OXA) resistance. An OXA-resistant colon cancer cell line, SW480/OXA, was used to examine the effects of miR-188-5p on the sensitivity of colon cancer cells to OXA. The target of miR-188-5p was identified using a luciferase assay. Cell cycle distribution was also assessed using flow cytometry. The measurement of p21 protein expression, Hoechst 33342 staining and Annexin V/propidium iodide staining was used to evaluate apoptosis. The expression of miR-188-5p significantly increased in SW480/OXA compared with wild-type SW480 cells. The luciferase assay demonstrated that miR-188-5p inhibited Ras GTPase-activating protein 1 (RASA1; also known as p120/RasGAP) luciferase activity by binding to the 3'-untranslated region of RASA1 mRNA, suggesting that miR-188-5p could target RASA1. In addition, miR-188-5p downregulation or RASA1 overexpression promoted the chemosensitivity of SW480/OXA, as evidenced by increased apoptosis and G₁/S cell cycle arrest. Moreover, RASA1 silencing abrogated the increase in cell apoptosis induced by the miR-188-5p inhibitor. The findings of the present study suggested that miR-188-5p could enhance colon cancer cell chemosensitivity by promoting the expression of RASA1.

The clinical application value of miR-1269 as an unfavorable prognostic indicator of lung cancer

BACKGROUND

Thanks to microRNAs (miR), a myriad of outstanding achievements have been made in multiple fields in recent years. miR-1269, a newly discovered miR, presents high expression profiles in lung cancer (LC), but its clinical implications in LC have not been clarified yet.

METHODS

The miR-1269 expressions in the peripheral blood of LC patients, benign pulmonary disease (BPD) patients, and healthy controls were measured using qRT-PCR. Receiver operating characteristic (ROC) curves were employed for the identification of the diagnostic value of miR-1269 in LC, as were Kaplan-Meier (K-M) analyses and a Cox regression model to determine miR-1269's prognostic value in LC.

RESULTS

qRT-PCR revealed higher miR-1269 expressions in the LC patients than in the BPD patients and the controls (P < 0.001). The LC patients with high miR-1269 expressions had advanced tumor stages (III-IV) and an increased probability of lymph node metastasis (LNM) (P < 0.01). Also, evidently elevated miR-1269 levels were observed in the peripheral blood of patients with the advanced tumor stages (III-IV) and LNM. Via ROC curves, we found that miR-1269 is of high clinical significance in the diagnosis of LC and advanced tumor stages. Our K-M survival analysis revealed a lowered 5-year survival rate in patients with high miR-1269 expressions, and our Cox regression analysis found that miR-1269 is an independent prognostic factor for LC.

CONCLUSIONS

miR-1269, with high expression profiles in LC, indicates unfavorable patient prognoses, so it may be a viable diagnostic and prognostic indicator of LC.

SNHG15 facilitated malignant behaviors of oral squamous cell carcinoma through targeting miR-188-5p/DAAM1

BACKGROUND

Long non-coding RNA (lncRNA) small nucleolar RNA host gene 15 (SNHG15) has been discovered and demonstrated to have significant function in multiple cancers. Nevertheless, how it participates in the progression of oral squamous cell carcinoma (OSCC) and its potential regulatory system are still unclear.

METHODS

RT-qPCR detected the expression of SNHG15, miR-188-5p, and DAAM1. RNA pull down, RT-qPCR, and bioinformatics were used for finding and selecting downstream targets of SNHG15.

RESULTS

SNHG15 presented a high expression in OSCC cells. Moreover, inhibition of SNHG15 exhibited repressive influence on proliferative, migrated, and invasive abilities but induce apoptosis of OSCC cells. Through the search of bioinformatics and RNA pull down assays, we confirmed that miR-188-5p was one target of SNHG15 in OSCC cells. Additionally, miR-188-5p could hamper the growth of OSCC cells. Moreover, it was manifested that DAAM1 was down-regulated by miR-188-5p. DAAM1 was up-regulated in OSCC cells. Furthermore, it exerted oncogenic function in the course of OSCC. Eventually, overexpression of DAAM1 offsets the effects of down-regulation of SNHG15 on the development of OSCC.

CONCLUSION

To summarize, our study certified that SNHG15 contributed to the process of OSCC via sponging miR-188-5p to elevate DAAM1 expression. SNHG15 might offer novel sight to improve the results of treatment for OSCC.

LncRNA HCG18 contributes to the progression of hepatocellular carcinoma via miR-214-3p/CENPM axis

Long non-coding RNA (lnc) HCG18 has been reported to contribute progression of a variety of tumours. However, its roles in hepatocellular carcinoma (HCC) remains unknown. In the current study, we intended to uncover the biological functions of HCG18 in HCC. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to detect the expression of HCG18, microRNA-214-3p (miR-214-3p) and centromere protein M (CENPM) messenger RNA (mRNA). The role of HCG18 in the growth and migration were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, colony formation assay, wound healing assay and flow cytometry in vitro and animal experiments in vivo. The results showed that HCG18 was highly expressed in HCC tissues. HCG18 silencing inhibited the proliferation and migration while induced the apoptosis of HCC cells. Besides, miR-214-3p was down-regulated in HCC cells. Further experiments revealed that miR-214-3p could directly bind to HCG18 and exerted an anti-tumour role to counteracted siHCG18-1-mediated influence in HCC cells. Moreover, miR-214-3p could directly interact with CENPM mRNA and down-regulating the expression of CENPM. While HCG18 could up-regulate the expression of CENPM through acting as a sponge of miR-214-3p. Therefore, those results suggested HCG18 functioned as an oncogene to promote the proliferation and migration of HCC cells via miR-214-3p/CENPM axis.

Honokiol antagonizes doxorubicin resistance in human breast cancer via miR-188-5p/FBXW7/c-Myc pathway

BACKGROUND

Honokiol, a natural phenolic compound derived from Magnolia plants, is a promising anti-tumor compound that exerts a wide range of anti-cancer effects. Herein, we investigated the effect of honokiol on doxorubicin resistance in breast cancer.

METHODS

Doxorubicin-sensitive (MCF-7 and MDA-MB-231) and doxorubicin-resistant (MCF-7/ADR and MDA-MB-231/ADR) breast cancer cell lines were treated with doxorubicin in the absence or presence of honokiol; then, the following tests were performed: flow cytometry for cell apoptosis, WST-1 assay for cell viability, qPCR and western blot for the expression of miR-188-5p, FBXW7, and c-Myc. MiR-188-5p mimic, miR-188-5p inhibitor, siFBXW7, and c-Myc plasmids were transfected into cancer cells to evaluate whether miR-188-5p and FBXW7/c-Myc signaling are involved in the effect of honokiol on doxorubicin resistance in breast cancer. A dual luciferase reporter system was used to study the direct interaction between miR-188-5p and FBXW7.

RESULTS

Honokiol sensitized doxorubicin-resistant breast cancer cells to doxorubicin-induced apoptosis. Mechanically, upregulation of miR-188-5p was associated with doxorubicin resistance, and honokiol enhanced doxorubicin sensitivity by downregulating miR-188-5p. FBXW7 was confirmed to be a direct target gene of miR-188-5p. FBXW7/c-Myc signaling was involved in the chemosensitization effect of honokiol. Honokiol induced apoptosis in MCF-7/ADR and MDA-MB-231/ADR cells. However, FBXW7 silencing or c-Myc transfection resulted in resistance to the honokiol-induced apoptotic effect.

CONCLUSION

These findings suggest that downregulation of miR-188-5p by honokiol enhances doxorubicin sensitivity through FBXW7/c-Myc signaling in human breast cancer. Our study finds an important role of miR-188-5p in the development of doxorubicin resistance in breast cancer, and enriches our understanding of the mechanism of action of honokiol in cancer therapy.

miR-188-5p inhibits proliferation, migration, and invasion in gallbladder carcinoma by targeting Wnt2b and Smad2

Gallbladder carcinoma (GBC) commonly occurs in gastrointestinal malignancy and has the fifth highest mortality rate among gastrointestinal malignancy. Recently, miR-188-5p, a small noncoding RNA, has been implicated in various types of cancer such as nasopharyngeal carcinoma, oral squamous cell carcinoma, liver cancer, and prostate cancer. However, the effect of miR-188-5p on GBC remains unclear. Here, we demonstrated that miR-188-5p was downregulated in GBC tissues, and downregulation of miR-188-5p correlated with larger tumor size, lymph node metastasis, and extensive metastasis. In addition, the overall survival time of patients with higher miR-188-5p expression was significantly longer than that of patients with low-miR-188-5p expression. Moreover, downregulation of miR-188-5p promoted the proliferation, migration, and invasion of GBC cells, while its overexpression inhibited cell invasion and induced cell apoptosis, and arrested GBC growth in vivo. Importantly, miR-188-5p-dependent tumorigenesis was correlated with Wnt/β-catenin signaling and p-38/JNK signaling. In conclusion, miR-188-5p plays a direct role in GBC tumorigenesis. Our study suggests that miR-188-5p could serve as a novel diagnosis marker and therapeutic target in GBC.

Up-Regulation of miR-26a-5p Inhibits E2F7 to Regulate the Progression of Renal Carcinoma Cells

Background

Metastasis is the main cause of renal cell carcinoma (RCC) tumor death, and effective inhibition of RCC metastasis is an essential means to meliorate the prognosis of RCC patients. MicroRNAs (miRs) have been proved to be stable and important biomarkers for several malignancies. This study is therefore set out to explore the metastasis-related miR and its mechanism in RCC.

Methods

The expression of miR- 26a -5p in RCC was analyzed using the expression profile in the Cancer Genome Atlas (TCGA). MiR-26a-5p and E2F transcription factor 7 (E2F7) in RCC patients were detected by qRT-PCR. Cell Counting Kit-8 (CCK-8) was adopted to assess cell proliferation, Transwell was utilized to evaluate migration and invasion, and flow cytometry (FC) was used to determine apoptosis. Mouse cell-derived and patient-derived xenotransplantation models were established to evaluate the effect of miR-26a-5p on tumor growth and metastasis in vivo. The molecular mechanism of miR-26a-5p was analyzed by dual-luciferase reporter (DLR) gene analysis, qRT-PCR, and Western blot (WB) both in vivo and in vitro.

Results

MiR-26a-5p was reduced in renal carcinoma cells and may serve as a biomarker for renal cancer metastasis and prognosis. MiR-26a-5p up-regulation inhibited migration and invasion in renal cell lines and tumor metastasis in vivo. Bioinformatics target prediction and RNA-seq results showed that E2F7 was among the targets of miR-26a-5p and was significantly inhibited by miR-26a-5p in vivo and in vitro.

Conclusion

MiR-26a-5p presents low expression in RCC and promotes RCC cell apoptosis and prevents cells from proliferating and invading by targeting E2F7, which is a promising therapeutic target for RCC.

DARS-AS1 Knockdown Inhibits the Growth of Cervical Cancer Cells via Downregulating HMGB1 via Sponging miR-188-5p

Background:

Evidence has been shown that long noncoding RNAs (lncRNAs) play an important role in the development of cervical cancer. Recently, lncRNA DARS-AS1 was shown to be dysregulated in several cancer types, but the role of DARS-AS1 in cervical cancer remains unclear.

Methods:

Immunofluorescence staining, flow cytometry and transwell invasion assays were used to determine proliferation, apoptosis and invasion in cervical cancer cells, respectively. The dual luciferase reporter system assay was performed to assess the interaction between DARS-AS1, miR-188-5p, and high mobility group box 1 (HMGB1) in cervical cancer cells.

Results:

Downregulation of DARS-AS1 markedly inhibited the proliferation and invasion of cervical cancer cells. Moreover, DARS-AS1 knockdown obviously induced the apoptosis of SiHa and HeLa cells. Meanwhile, luciferase reporter assay identified that miR-188-5p was the potential miRNA binding of DARS-AS1, and HMGB1 was the potential binding target of miR-188-5p. Mechanistic analysis indicated that downregulation of DARS-AS1 decreased the expression of HMGB1 by acting as a competitive “sponge” of miR-188-5p.

Conclusion:

In this study, we found that DARS-AS1 knockdown suppressed the growth of cervical cancer cells via downregulating HMGB1 via sponging miR-188-5p. Therefore, DARS-AS1 might serve as a potential target for the treatment of cervical cancer.

MMP1 3'UTR facilitates the proliferation and migration of human oral squamous cell carcinoma by sponging miR-188-5p to up-regulate SOX4 and CDK4

Growing evidence indicates that the non-coding 3'-untranslated region (3'UTR) of genes acts as competing endogenous RNAs (ceRNAs) to exert their roles in a number of diseases, including cancer. In the present study, MMP1 messenger RNA was identified to be significantly up-regulated in oral squamous cell carcinoma (OSCC) tissues, and both MMP1 and its 3'UTR promoted tumor growth and cell motility. Further mechanism investigations indicated that MMP1 3'UTR was able to antagonize miR-188-5p; in addition, overexpression of MMP1 3'UTR up-regulated the expression level of SOX4 and CDK4, target genes of miR-188-5p, which have also been identified as oncogenic driver genes in OSCC. Therefore, a ceRNA regulatory network among MMP1, SOX4, and CDK4 mediated via competing for binding to miR-188-5p was proved. Taken together, the present study demonstrates for the first time that MMP1 mRNA participates in the development of OSCC via ceRNA regulatory mechanism and genes involved in the ceRNA network may provide a novel avenue for target therapy.

Circ-PTK2 promotes the proliferation and suppressed the apoptosis of acute myeloid leukemia cells through targeting miR-330-5p/FOXM1 axis

BACKGROUND

Acute myeloid leukemia (AML) is characterized by malignant clonal disorder of blood cells with high relapse rate and low survival rate. Circular RNAs (circRNAs) have shown their important regulatory roles in AML progression. Here, we intended to disclose the role of circular RNA protein tyrosine kinase 2 (circ-PTK2) in the progression of AML and illustrate the potential working mechanisms.

METHODS

3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and colony formation assay were conducted to analyze cell proliferation ability, and the apoptosis rate was assessed by flow cytometry. Dual-luciferase reporter assay was used to validate the direct interaction between microRNA-330-5p (miR-330-5p) and circ-PTK2 or forkhead box M1 (FOXM1).

RESULTS

Circ-PTK2 was highly expressed in AML. Circ-PTK2 interference suppressed the proliferation and triggered the apoptosis of AML cells. Circ-PTK2 directly bound to miR-330-5p. Si-circ-PTK2-mediated inhibition on the malignant behaviors of AML cells was partly counteracted by the addition of anti-miR-330-5p. MiR-330-5p directly interacted with FOXM1 messenger RNA (mRNA), and FOXM1 overexpression partly reversed miR-330-5p-induced influence in AML cells. Circ-PTK2 up-regulated FOXM1 expression through sponging miR-330-5p in AML cells.

CONCLUSION

Circ-PTK2 promoted the proliferation and hampered the apoptosis of AML cells through targeting miR-330-5p/FOXM1 axis.

MiR-422a in gastric cancer cells directly targets CDC40 and modulates cell proliferation

MicroRNAs have been shown to be involved in a variety of different human cancers, including gastric cancer, functioning as post-transcriptional regulators of oncogenes or tumor suppressors. This study aimed to clarify the role of miR-422a in gastric cancer and further elucidate the pathogenesis thereof. To this end, miR-422a expression was initially determined in gastric cancer tissues and cells. Our results showed decreased miR-422a and increased cell division cycle 40 (CDC40) expression in gastric cancer. Dual-luciferase reporter assay further confirmed that miR-422a targeted CDC40. Altogether, this study showed that miR-422a downregulated CDC40, thereby affecting cell cycle progression. Moreover, restoration of miR-422a inhibited gastric cancer cell proliferation. In summary, this study has been the first to show that miR-422a was associated with CDC40 levels in human gastric cancer cells and that disease development may be attributed to CDC40.

MicroRNA‑188‑5p inhibits the progression of breast cancer by targeting zinc finger protein 91

Breast cancer (BC) is the most commonly diagnosed malignant cancer in women. BC is the main cause of cancer-related death in women and seriously threatens the life and health of women worldwide. MicroRNAs (miRNAs/miRs) have been reported to regulate the development and progression of different types of cancer. However, the regulatory functions of miR-188-5p in BC have not been thoroughly demonstrated. In this present research, we identified that miR-188-5p was downregulated in BC tissues and several BC cell lines. Downregulation of miR-188-5p was significantly associated with advanced TNM stage. Moreover, we identified that miR-188-5p mimics significantly inhibited proliferation using CCK-8 assay, colony formation and xenograft animal model, suppressed invasion and migration detected by Transwell invasion assay, and increased the cellular apoptosis of BC cells as determined by cell apoptosis assay. Moreover miR-188-5p mimics also reduced the expression of NF-κB p65(Rel). To further investigate its regulatory mechanism, transcription factor zinc finger protein 91 (ZFP91) was predicted as the targeted protein of miR-188-5p by bioinformatic method. We confirmed their specific binding by dual luciferase (DLR) assay. We demonstrated that the overexpression of miR-188-5p significantly inhibited the expression of ZFP91 in BC cell lines and reduced the expression of NF-κB p65(Rel). An inverse correlation was found between the expression of miR-188-5p and ZFP91 in BC tissues. Importantly, we demonstrated that the restoration of ZFP91 was able to block the effect of miR-188-5p on the progression of MDA-MB-231 cells. Therefore, our study showed that miR-188-5p may be one of the important indicators and could inhibit the progression of human BC via targeting the ZFP91/NF-κB p65(Rel) signaling pathway, suggesting that miR-188-5p may be a promising future target for BC treatment.

MicroRNAs in cancer therapy: Their involvement in oxaliplatin sensitivity/resistance of cancer cells with a focus on colorectal cancer

The resistance of cancer cells into chemotherapy has restricted the efficiency of anti-tumor drugs. Oxaliplatin (OX) being an anti-tumor agent/drug is extensively used in the treatment of various cancer diseases. However, its frequent application has led to chemoresistance. As a consequence, studies have focused in finding underlying molecular pathways involved in OX resistance. MicroRNAs (miRs) are short endogenous non-coding RNAs that are able to regulate vital biological mechanisms such as cell proliferation and cell growth. The abnormal expression of miRs occurs in pathological events, particularly cancer. In the present review, we describe the involvement of miRs in OX resistance and sensitivity. The miRs are able to induce the oncogene factors and mechanisms, resulting in stimulation OX chemoresistance. Also, onco-suppressor miRs can enhance the sensitivity of cancer cells into OX chemotherapy and trigger apoptosis and cell cycle arrest, leading to reduced viability and progression of cancer cells. MiRs can also enhance the efficacy of OX chemotherapy. It is worth mentioning that miRs affect various down-stream targets in OX resistance/sensitivity such as STAT3, TGF-β, ATG4B, FOXO1, LATS2, NF-κB and so on. By identification of these miRs and their upstream and down-stream mediators, further studies can focus on targeting them to sensitize cancer cells into OX chemotherapy and induce apoptotic cell death.

lncRNA MALAT1 modulates oxaliplatin resistance of gastric cancer via sponging miR-22-3p

Objective

Various regulatory mechanisms have been demonstrated to be associated with cancer progression. ncRNA and mRNA play important roles in gastric cancer (GC) cell growth and drug resistance, respectively. However, the regulatory network of ncRNA and mRNA in GC oxaliplatin (OXA) resistance has not been fully clarified.

Methods

The expression of miR-22-3p, MALAT1, and zinc finger protein 91 (ZFP91) was detected in tissues and cells using quantitative real-time PCR. The protein level of ZFP91 was measured by Western blot analysis. Luciferase reporter, pull-down, and RNA immunoprecipitation assays were used to determine the relationship between MALAT1, miR-22-3p, and ZFP91. MTT assay was applied to measure cell survival and proliferation. Cell apoptosis was detected using flow cytometry. Tumor xenograft assay was used to detect the function of miR-22-3p in vivo.

Results

In this study, we found that MALAT1 and ZFP91 expression was upregulated while the expression of miR-22-3p was downregulated in GC/OXA tissues and cells. Additionally, miR-22-3p was a target miRNA of MALAT1 and ZFP91 was a target mRNA of miR-22-3p. Functional studies showed that the knockdown of MALAT1 or overexpression of miR-22-3p inhibited GC/OXA cell survival, proliferation, and drug resistance as well as induced apoptosis, which could be reversed by the inhibition of miR-22-3p or overexpression of ZFP91.

Conclusion

We observed a new regulatory network for MALAT1 in drug resistance of GC. MALAT1 modulates ZFP91 to promote GC cells OXA resistance via sponging miR-22-3p.

Novel replisome-associated proteins at cellular replication forks in EBV-transformed B lymphocytes

Epstein-Barr virus (EBV) is an oncogenic herpesvirus and WHO class 1 carcinogen that resides in B lymphocytes of nearly all humans. While silent in most, EBV can cause endemic Burkitt lymphoma in children and post-transplant lymphoproliferative disorders/lymphomas in immunocompromised hosts. The pathogenesis of such lymphomas is multifactorial but to a large extent depends on EBV’s ability to aggressively drive cellular DNA replication and B cell proliferation despite cell-intrinsic barriers to replication. One such barrier is oncogenic replication stress which hinders the progression of DNA replication forks. To understand how EBV successfully overcomes replication stress, we examined cellular replication forks in EBV-transformed B cells using iPOND (isolation of Proteins on Nascent DNA)-mass spectrometry and identified several cellular proteins that had not previously been linked to DNA replication. Of eight candidate replisome-associated proteins that we validated at forks in EBV-transformed cells and Burkitt lymphoma-derived cells, three zinc finger proteins (ZFPs) were upregulated early in B cells newly-infected with EBV in culture as well as expressed at high levels in EBV-infected B blasts in the blood of immunocompromised transplant recipients. Expressed highly in S- and G2-phase cells, knockdown of each ZFP resulted in stalling of proliferating cells in the S-phase, cleavage of caspase 3, and cell death. These proteins, newly-identified at replication forks of EBV-transformed and Burkitt lymphoma cells therefore contribute to cell survival and cell cycle progression, and represent novel targets for intervention of EBV-lymphomas while simultaneously offering a window into how the replication machinery may be similarly modified in other cancers.

Cancer cells must overcome chronic replication stress, a central barrier to DNA replication. This is true also for cancers caused by Epstein-Barr virus (EBV). To understand how EBV overcomes this barrier to successfully drive cell proliferation, we isolated proteins associated with the cellular replication machinery in EBV-transformed B lymphocytes and identified several cellular proteins that had not previously been linked to DNA replication in cancer or healthy cells. Three of these were zinc finger proteins enriched at the replication machinery in EBV-transformed and EBV-positive Burkitt lymphoma-derived cells, upregulated in newly-infected B cells, and expressed at high levels in infected B cells from transplant recipients. These zinc finger proteins also contributed towards cell proliferation, survival, and cell cycle progression. While these proteins may also contribute to DNA replication in other cancers, they simultaneously represent potential targets in EBV-cancers, some of which are difficult to treat.

miR-188-5p suppresses cellular proliferation and migration via IL6ST: A potential noninvasive diagnostic biomarker for breast cancer

Previously, serum miR-188-5p is differentially expressed in breast cancer, but the diagnostic potential of circulating miR-188-5p as well as its regulatory mechanism in breast cancer remain uncertain. Herein, serum miR-188-5p was detected by real-time polymerase chain reaction in patients with breast cancer, breast fibroadenoma, and healthy subjects. Circulating miR-188-5p was abnormally elevated in patients with breast cancer as compared with these other two groups, and was reduced in patients with breast cancer following surgical treatment. Increased serum miR-188-5p corresponded to lymph node metastasis status and TNM stages of breast cancer. A receiver operating characteristic curve analysis of the ability to circulate miR-188-5p to distinguish between patients with breast cancer and either noncancerous patients or patients with breast fibroadenoma yielded corresponding areas under the curve of 0.894 and 8.814. miR-188-5p was downregulated in the highly malignant cancer line MDA-MB-231 relative to the less malignant MCF-7 cells. In vitro, functional analyses conducted via transfecting cells with mimics and inhibitors revealed miR-188-5p to suppress breast cancer cell proliferation and migration, which was mediated by its downstream target IL6ST. Comparison of intracellular and exosomal miR-188-5p levels indicated that miR-188-5p was selectively sorted into exosomes derived from MDA-MB-231 cells rather than those from MCF-7 cells. However, exosomal miR-188-5p levels in the serum of patients with breast cancer were reduced compared to healthy controls and did not differ relative to patients with breast fibroadenoma. In summary, miR-188-5p acts in a tumor-suppressive manner in breast cancer progression and may serve as a noninvasive early diagnostic biomarker and therapeutic target in breast cancer.

MicroRNA-188-5p promotes apoptosis and inhibits cell proliferation of breast cancer cells via the MAPK signaling pathway by targeting Rap2c

Breast cancer is a common malignancy that is highly lethal with poor survival rates and immature therapeutics that urgently needs more effective and efficient therapies. MicroRNAs are intrinsically involved in different cancer remedies, but their mechanism in breast cancer has not been elucidated for prospective treatment. The function and mechanism of microRNA-188-5p (miR-188) have not been thoroughly investigated in breast cancer. In our study, we found that the expression of miR-188 in breast cancer tissues was obviously reduced. Our findings also revealed the abnormal overexpression of miR-188 in 4T1 and MCF-7 cells significantly suppressed cell proliferation and migration and also enhanced apoptosis. miR-188 induced cell cycle arrest in the G1 phase. To illuminate the molecular mechanism of miR-188, Rap2c was screened as a single target gene by bioinformatics database analysis and was further confirmed by dual-luciferase assay. Moreover, Rap2c was found to be a vital molecular switch for the mitogen-activated protein kinase signaling pathway in tumor progression by decreasing apoptosis and promoting proliferation and migration. In conclusion, our results revealed that miR-188 is a cancer progression suppressor and a promising future target for breast cancer therapy.

Long noncoding RNA SBF2-AS1 act as a ceRNA to modulate cell proliferation via binding with miR-188-5p in acute myeloid leukemia

LncRNA SBF2-AS1 has been reported to be implicated in the deterioration of multiple human cancers. However, the roles and underlying mechanisms of SBF2-AS1 in acute myeloid leukemia (AML) are still unclear. In the present study, the online GEPIA database showed that SBF2-AS1 expression was significantly increased in AML samples. QRT-PCR results showed that SBF2-AS1 expression was upregulated in AML cells. CCK-8 assay revealed that SBF2-AS1 inhibition decreased AML cells proliferation ability in vitro. Flow cytometry assays showed that SBF2-AS1 inhibition induced AML cells apoptosis and arrested AML cells in G0/G1 phase. Mechanistically, miR-188-5p was identified as a direct target of SBF2-AS1. SBF2-AS1 upregulated the expression level of ZFP91 by sponging miR-188-5p. And the effects of SBF2-AS1 suppression on AML cells progression could be abolished by miR-188-5p inhibitors. Moreover, we found that SBF2-AS1 inhibition reduced tumor growth in vivo. Taken together, our findings elucidated that SBF2-AS1 could act as a miRNA sponge in AML progression, and provided a potential therapeutic strategy for AML treatment.

MiR-188-5p and MiR-141-3p influence prognosis of bladder cancer and promote bladder cancer synergistically

MicroRNA (miRNA) plays a significant role in suppressing the occurrence and development of tumor by inhibiting the translation of target proteins. Although previous researches have verified many miRNAs' functions in bladder cancer (BC), the function of miR-188-5p and miR-141-3p in BC still remains unknown. Our experiment manifested that miR-188-5p and miR-141-3p were highly expressed in BC tissues and cells, which indicated a poor prognosis. In vitro functional assays suggested that down-regulated miR-188-5p and miR-141-3p inhibited the proliferation, migration and invasion of BC cells, while a combination of half dose down-regulated miR-188-5p and half dose down-regulated miR-141-3p demonstrated a more obvious inhibition effect. All results indicated that miR-188-5p and miR-141-3p promoted BC respectively and synergistically. Therefore, miR-188-5p and miR-141-3p will not only assist the diagnosis of BC, but also serve as more effective joint markers to predict the progression of BC.

MicroRNA-188 inhibits proliferation migration and invasion of prostate carcinoma by targeting at MARCKS

Recent evidences suggested that miRNAs process key roles in the biological behaviors and the development of prostate carcinoma (PC). However, its molecular mechanism in PC is still remained largely unclear. In this study, the expression level of miR-188 and the protein expression of MARCKS were detected by RT-PCR and western blot, respectively. Moreover, we determined the oncogene or anti-oncogene role of miR-188 in the PC through gain and loss function assay of miR-188 using transfection of miR-188 mimics and inhibitor. Meanwhile, luciferase reporter vectors with miR-188 mimics were constructed and transfected into PC cells. Our data indicated that the expression of miR-188 was dramatically reduced in human PC tissues and cell lines and the increased miR-188 levels obviously inhibited the proliferation, migration and invasion of PC cells and negatively regulative with MARCKS. Together, our findings proved that miR-188 plays an inhibitive role in PC of proliferation, migration and invasion at least in part via suppressing MARCKS expression, which could be regarded as a promising therapeutic target in PC.

Aberrantly expressed miR-188-5p promotes gastric cancer metastasis by activating Wnt/β-catenin signaling

Background

Gastric cancer (GC) is one of the most common human cancers with the high rate of recurrence, metastasis and mortality. Aberrantly expressed microRNAs (miRNAs) are associated with invasion and metastasis in various human cancers. Recently, miR-188-5p has been indicated as an oncogene in GC since it promotes GC cell growth and metastasis. However, the underlying molecular mechanism remains to be fully defined.

Methods

Using Significance Analysis of Microarrays (SAM) screening, we identified that miR-188-5p is associated with overall survival and lymph node metastasis in patients with GC. The functional impact of miR-188-5p on GC metastasis was validated using in vitro and in vivo assays. The regulatory function of miR-188-5p on Wnt/β-catenin signaling activation through directly targeting PTEN was proven using quantitative real-time PCR, western blot analysis, a dual-luciferase assay, a Transwell assay, and immunofluorescence. Immunohistochemical analyses further confirmed the clinical significance of miR-188-5p in GC.

Results

MiR-188-5p diminishes tumor suppressor PTEN expression, and further increases phospho-Ser9 of GSK3β to activate Wnt/β-catenin signaling in GC. Consequently, miR-188-5p enhanced the migration and invasion of GC cells in vitro and tumor metastasis in vivo, whereas inhibition of miR-188-5p had the opposite effects. Moreover, miR-188-5p was negatively correlated with PTEN expression but positively correlated with nuclear β-catenin staining in GC samples.

Conclusions

Our findings revealed a model of the miR-188-5p-PTEN-β-catenin axis in GC, which mediates the constitutive activation of Wnt/β-catenin signaling and promotes tumor metastasis, inferring that miR-188-5p is a potential therapeutic target to treat GC.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5731-0) contains supplementary material, which is available to authorized users.

miR-188-5p emerges as an oncomiRNA to promote gastric cancer cell proliferation and migration via upregulation of SALL4

MicroRNAs (miRNAs) play pivotal roles in modulating key biological processes in gastric cancer (GC). As a newly identified miRNA, the function and potential mechanism of miR-188-5p in GC has not been thoroughly elucidated. Here, quantitative real-time polymerase chain reaction detection showed abnormally higher expression of miR-188-5p in GC cells and tissues. Gain-of-function analysis in vitro showed that miR-188-5p promoted GC cell proliferation and migration, while loss-of-function studies showed the reverse. Targetscan has predicted that phosphatase and tensin homolog (PTEN) was a potential target gene of miR-188-5p. miR-188-5p suppressed PTEN messenger RNA and protein expression and activated downstream AKT/mTOR signaling in GC cells, but luciferase reporter analysis showed that PTEN was not regulated by miR-188-5p via the 3' untranslated region. Furthermore, we observed that miR-188-5p overexpression promoted Sal-like protein 4 (SALL4) protein expression, cellular nuclear translocation, and transcription. Knockdown of SALL4 eliminated the effect of miR-188-5p in GC cells as well as suppression of PTEN. Taken together, our results demonstrate that miR-188-5p promotes GC cell proliferation and migration while suppressing tumor suppressor gene PTEN expression via transcriptional upregulation of oncogene SALL4. We conclude that miR-188-5p acts as an oncomiRNA in GC and may be a promising therapeutic target for GC.

TMED3 promotes cell proliferation and motility in breast cancer and is negatively modulated by miR-188-3p

BACKGROUND

The role of TMED3 involved in cancers has been seldom described, let alone in breast cancer. To explore the clinicopathological significance of TMED3 expression and the biological roles involved in breast cancer cells, we undertook the study.

METHODS

Immunohistochemistry was performed to observe the pattern of TMED3 expression in breast cancer tissues, totaling 224 cases; followed by detailed statistical analysis between TMED3 expression versus clinicopathological information available. To explore the role of TMED3 involved in the malignant behaviors of breast cancer cells, wound-healing and Transwell assays were conducted to evaluate the variation of migration and invasion of MCF-7 and MDA-MB-231 cells whose TMED3 has been stably silenced using lenti-viral based short hairpin RNA (shRNA) vectors. MTT, clonogenic assay and xenograft nude mice model were undertaken to observe the variation of proliferation both in vitro and in vivo.

RESULTS

It was shown that elevated TMED3 markedly correlated with ER, PR, Her-2 status, and lymph nodes metastases in addition to significant association with poor overall prognosis. In vitro, TMED3 was shown to promote proliferation, migration and invasion of breast cancer cells. Moreover, miR-188-3p was identified as a novel negative regulator of TMED3 in breast cancer, which can slow down the proliferation, migration and invasion of MCF-7 cells. Results from in vivo xenograft nude mice models showed that lenti-viral based miR-188-3p re-expression can markedly impair the tumor growth.

CONCLUSIONS

Our data define and bolster the oncogenic role of TMED3 in breast cancer.

LncRNA PAPAS promotes hepatocellular carcinoma by interacting with miR-188-5p

It has been observed that long noncoding RNA (lncRNA) PAPAS regulates rRNA synthesis, but its role in human diseases is unclear. Our study was carried out to investigate the role of PAPAS in hepatocellular carcinoma (HCC). In the present study, we found that PAPAS was upregulated both in plasma from patients with HCC and tumors compared with plasma from healthy people and tumor-adjacent healthy tissues. Expression levels of PAPAS in tumor tissues and plasma of patients with HCC were significantly and positively correlated. Plasma levels of PAPAS effectively distinguished stage I patients from healthy controls. MicroRNA (miR)-188-5p was downregulated in tumor tissues than in tumor-adjacent healthy tissues of patients with HCC, and was inversely correlated with PAPAS in tumor tissues but not in adjacent healthy tissues. PAPAS and miR-188-5p downregulated each other. PAPAS overexpression promoted, while miR-188-5p overexpression inhibited the HCC cell proliferation. Rescue experiment showed that miR-34a overexpression attenuated the effects of PAPAS overexpression. However, PAPAS overexpression failed to affect significantly cancer cell migration and invasion. Therefore, lncRNA PAPAS promotes HCC by interacting with miR-188-5p.

miR-188-5p regulates proliferation and invasion via PI3K/Akt/MMP-2/9 signaling in keloids

Keloids (KDs) and hypertrophic scars (HSs), two forms of pathological scars, seriously affect the physical and psychological health of patients. Despite many similarities with HSs, KDs are characterized by invasion and a high rate of recurrence after surgery, features they share in common with tumors. The underlying molecular mechanisms of this phenomenon have not been fully elucidated. In this study, we used microRNA (miRNA) array analysis to search for invasion-associated miRNAs in KDs. The expression of miR-188-5p in KDs, HSs, normal skin (NS) tissues, and cell lines was measured by quantitative real-time polymerase chain reaction. Furthermore, cell proliferation, migration, and invasion were detected in KD fibroblasts (KFs) and HS fibroblasts (HSFs), and interrelated proteins were ascertained by western blot analysis. It was found that miR-188-5p was significantly decreased in KD tissue compared with HS and NS tissues. Upregulated expression of miR-188-5p suppressed KF proliferation, migration, and invasion; and decreased expression of miR-188-5p also promoted HSF proliferation, migration, and invasion. The protein levels of MMP-2, MMP-9, PI3K, and p-Akt in miR-188-5p mimic-transfected KFs were repressed. In contrast, after transfection with miR-188-5p inhibitor, the protein levels of MMP-2, MMP-9, PI3K, and p-Akt were higher than the control in HSFs. Treatment with PI3K/Akt inhibitor LY294002 in KFs with miR-188-5p inhibitor did not further reduce their proliferation, migration, and invasion. The upregulation of MMP-2 and MMP-9 by miR-188-5p inhibitor could be abolished by LY294002. These findings together demonstrate a tumor-suppressive role of miR-188-5p in KD proliferation and invasion via PI3K/Akt/MMP-2/9 signaling, indicating that miR-188-5p may be a potential prognostic marker and therapeutic target for KDs.

MicroRNA‑509 targets PAX6 to inhibit cell proliferation and invasion in papillary thyroid carcinoma

MicroRNAs (miRNAs/miRs) negatively regulate the expression of numerous genes and therefore contribute to the occurrence and development of papillary thyroid carcinoma (PTC). Hence, further investigation into the specific roles of miRNAs in PTC is valuable for developing effective therapeutic methods for patients with this disease. MiRNA‑509 is dysregulated and serves pivotal roles in several types of human cancer; however, the expression and roles of miR‑509 in PTC and its underlying mechanism require further investigation. In the present study, the expression of miR‑509 in PTC tissues and cell lines was detected and the specific functions of miR‑509 in the progression of PTC were investigated. Additionally, the molecular mechanisms underlying the action of miR‑509 in PTC were determined. The present study demonstrated that miR‑509 was significantly downregulated in PTC tissues and cell lines. MiR‑509 upregulation inhibited the PTC cell proliferation and invasion. Mechanistically, paired box 6 (PAX6) was identified as a novel target of miR‑509 in PTC cells. In clinical PTC samples, miR‑509 was significantly overexpressed and inversely correlated with PAX6 expression. PAX6 restoration effectively reversed the inhibitory effects of miR‑509 overexpression on PTC cell proliferation and invasion. These results demonstrated that miR‑509 may act as a tumor suppressor in PTC by directly targeting PAX6. Thus, miR‑509 may be a potential therapeutic target for the treatment of patients with PTC.

MicroRNAs as Potential Biomarkers in Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a rare and aggressive type of skin cancer associated with a poor prognosis. This carcinoma was named after its presumed cell of origin, the Merkel cell, which is a mechanoreceptor cell located in the basal epidermal layer of the skin. Merkel cell polyomavirus seems to be the major causal factor for MCC because approximately 80% of all MCCs are positive for viral DNAs. UV exposure is the predominant etiological factor for virus-negative MCCs. Intracellular microRNA analysis between virus-positive and virus-negative MCC cell lines and tumor samples have identified differentially expressed microRNAs. Comparative microRNA profiling has also been performed between MCCs and other non-MCC tumors, but not between normal Merkel cells and malignant Merkel cells. Finally, Merkel cell polyomavirus encodes one microRNA, but its expression in virus-positive MCCs is low, or non-detectable or absent, jeopardizing its biological relevance in tumorigenesis. Here, we review the results of microRNA studies in MCCs and discuss the potential application of microRNAs as biomarkers for the diagnosis, progression and prognosis, and treatment of MCC.