miR-202 Diminishes TGFβ Receptors and Attenuates TGFβ1-Induced EMT in Pancreatic Cancer

Intersecting pathways: The role of hybrid E/M cells and circulating tumor cells in cancer metastasis and drug resistance

Cancer metastasis and therapy resistance are intricately linked with the dynamics of Epithelial-Mesenchymal Transition (EMT) and Circulating Tumor Cells (CTCs). EMT hybrid cells, characterized by a blend of epithelial and mesenchymal traits, have emerged as pivotal in metastasis and demonstrate remarkable plasticity, enabling transitions across cellular states crucial for intravasation, survival in circulation, and extravasation at distal sites. Concurrently, CTCs, which are detached from primary tumors and travel through the bloodstream, are crucial as potential biomarkers for cancer prognosis and therapeutic response. There is a significant interplay between EMT hybrid cells and CTCs, revealing a complex, bidirectional relationship that significantly influences metastatic progression and has a critical role in cancer drug resistance. This resistance is further influenced by the tumor microenvironment, with factors such as tumor-associated macrophages, cancer-associated fibroblasts, and hypoxic conditions driving EMT and contributing to therapeutic resistance. It is important to understand the molecular mechanisms of EMT, characteristics of EMT hybrid cells and CTCs, and their roles in both metastasis and drug resistance. This comprehensive understanding sheds light on the complexities of cancer metastasis and opens avenues for novel diagnostic approaches and targeted therapies and has significant advancements in combating cancer metastasis and overcoming drug resistance.

Transcriptome sequencing reveals non-coding RNAs respond to porcine reproductive and respiratory syndrome virus and Haemophilus parasuis co-infection in Kele piglets

Co-infection with porcine reproductive and respiratory syndrome virus (PRRSV) and Haemophilus parasuis (HPS) has severely restricted the healthy development of pig breeding. Exploring disease resistance of non-coding RNAs in pigs co-infected with PRRSV and HPS is therefore critical to complement and elucidate the molecular mechanisms of disease resistance in Kele piglets and to innovate the use of local pig germplasm resources in China. RNA-seq of lungs from Kele piglets with single-infection of PRRSV or HPS and co-infection of both pathogens was performed. Two hundred and twenty-five differentially expressed long non-coding RNAs (DElncRNAs) and 30 DEmicroRNAs (DEmiRNAs) were identified and characterized in the PRRSV and HPS co-infection (PRRSV-HPS) group. Compared with the single-infection groups, 146 unique DElncRNAs, 17 unique DEmiRNAs, and 206 target differentially expressed genes (DEGs) were identified in the PRRSV-HPS group. The expression patterns of 20 DEmiRNAs and DElncRNAs confirmed by real-time quantitative polymerase chain reaction (RT-qPCR) were consistent with those determined by high-throughput sequencing. In the PRRSV-HPS group, the target DEGs were enriched in eight immune Gene Ontology terms relating to two unique DEmiRNAs and 16 DElncRNAs, and the unique target DEGs participated the host immune response to pathogens infection by affecting 15 immune-related Kyoto Encyclopedia of Genes and Genomes enrichment pathways. Notably, competitive endogenous RNA (ceRNA) networks of different groups were constructed, and the ssc-miR-671-5p miRNA was validated as a potential regulatory factor to regulate DTX4 and AEBP1 genes to achieve innate antiviral effects and inhibit pulmonary fibrosis by dual-luciferase reporter assays. These results provided insight into further study on the molecular mechanisms of resistance to PRRSV and HPS co-infection in Kele piglets.

MicroRNAs as the critical regulators of epithelial mesenchymal transition in pancreatic tumor cells

Pancreatic cancer (PC), as one of the main endocrine and digestive systems malignancies has the highest cancer related mortality in the world. Lack of the evident clinical symptoms and appropriate diagnostic markers in the early stages of tumor progression are the main reasons of the high mortality rate among PC patients. Therefore, it is necessary to investigate the molecular pathways involved in the PC progression, in order to introduce novel early diagnostic methods. Epithelial mesenchymal transition (EMT) is a critical cellular process associated with pancreatic tumor cells invasion and distant metastasis. MicroRNAs (miRNAs) are also important regulators of EMT process. In the present review, we discussed the role of miRNAs in regulation of EMT process during PC progression. It has been reported that the miRNAs mainly regulate the EMT process in pancreatic tumor cells through the regulation of EMT-specific transcription factors and several signaling pathways such as WNT, NOTCH, TGF-β, JAK/STAT, and PI3K/AKT. Considering the high stability of miRNAs in body fluids and their role in regulation of EMT process, they can be introduced as the non-invasive diagnostic markers in the early stages of malignant pancreatic tumors. This review paves the way to introduce a non-invasive EMT based panel marker for the early tumor detection among PC patients.

Fundamental insights and molecular interactions in pancreatic cancer: Pathways to therapeutic approaches

The gastrointestinal tract can be affected by a number of diseases that pancreatic cancer (PC) is a malignant manifestation of them. The prognosis of PC patients is unfavorable and because of their diagnosis at advanced stage, the treatment of this tumor is problematic. Owing to low survival rate, there is much interest towards understanding the molecular profile of PC in an attempt in developing more effective therapeutics. The conventional therapeutics for PC include surgery, chemotherapy and radiotherapy as well as emerging immunotherapy. However, PC is still incurable and more effort should be performed. The molecular landscape of PC is an underlying factor involved in increase in progression of tumor cells. In the presence review, the newest advances in understanding the molecular and biological events in PC are discussed. The dysregulation of molecular pathways including AMPK, MAPK, STAT3, Wnt/β-catenin and non-coding RNA transcripts has been suggested as a factor in development of tumorigenesis in PC. Moreover, cell death mechanisms such as apoptosis, autophagy, ferroptosis and necroptosis demonstrate abnormal levels. The EMT and glycolysis in PC cells enhance to ensure their metastasis and proliferation. Furthermore, such abnormal changes have been used to develop corresponding pharmacological and nanotechnological therapeutics for PC.

Molecular profile of metastasis, cell plasticity and EMT in pancreatic cancer: a pre-clinical connection to aggressiveness and drug resistance

The metastasis is a multistep process in which a small proportion of cancer cells are detached from the colony to enter into blood cells for obtaining a new place for metastasis and proliferation. The metastasis and cell plasticity are considered major causes of cancer-related deaths since they improve the malignancy of cancer cells and provide poor prognosis for patients. Furthermore, enhancement in the aggressiveness of cancer cells has been related to the development of drug resistance. Metastasis of pancreatic cancer (PC) cells has been considered one of the major causes of death in patients and their undesirable prognosis. PC is among the most malignant tumors of the gastrointestinal tract and in addition to lifestyle, smoking, and other factors, genomic changes play a key role in its progression. The stimulation of EMT in PC cells occurs as a result of changes in molecular interaction, and in addition to increasing metastasis, EMT participates in the development of chemoresistance. The epithelial, mesenchymal, and acinar cell plasticity can occur and determines the progression of PC. The major molecular pathways including STAT3, PTEN, PI3K/Akt, and Wnt participate in regulating the metastasis of PC cells. The communication in tumor microenvironment can provide by exosomes in determining PC metastasis. The components of tumor microenvironment including macrophages, neutrophils, and cancer-associated fibroblasts can modulate PC progression and the response of cancer cells to chemotherapy.

Interplay between LncRNA/miRNA and TGF-β Signaling in the Tumorigenesis of Gynecological Cancer

Gynecologic cancers are among the most common malignancies with aggressive features and poor prognosis. Tumorigenesis in gynecologic cancers is a complicated process that is influenced by multiple factors, including genetic mutations that activate various oncogenic signaling pathways, including the TGF-β pathway. Aberrant activation of TGF-β signaling is correlated with tumor recurrence and metastasis. It has been shown that non-coding RNAs (ncRNAs) have crucial effects on cancer cell proliferation, migration, and metastasis. Upregulation of various ncRNAs, including long non-coding RNAs (lncRNA) and microRNAs (miRNAs), has been reported in several tumors, like cervical, ovarian, and endometrial cancers, but their cellular mechanisms remain to be investigated. Thus, recognizing the role of ncRNAs in regulating the TGF-β pathway may provide novel strategies for better treatment of cancer patients. The present study summarizes recent findings on the role of ncRNAs in regulating the TGF-β signaling involved in tumor progression and metastasis in gynecologic cancers.

Increased renal elimination of endogenous and synthetic pyrimidine nucleosides in concentrative nucleoside transporter 1 deficient mice

Concentrative nucleoside transporters (CNTs) are active nucleoside influx systems, but their in vivo roles are poorly defined. By generating CNT1 knockout (KO) mice, here we identify a role of CNT1 in the renal reabsorption of nucleosides. Deletion of CNT1 in mice increases the urinary excretion of endogenous pyrimidine nucleosides with compensatory alterations in purine nucleoside metabolism. In addition, CNT1 KO mice exhibits high urinary excretion of the nucleoside analog gemcitabine (dFdC), which results in poor tumor growth control in CNT1 KO mice harboring syngeneic pancreatic tumors. Interestingly, increasing the dFdC dose to attain an area under the concentration-time curve level equivalent to that achieved by wild-type (WT) mice rescues antitumor efficacy. The findings provide new insights into how CNT1 regulates reabsorption of endogenous and synthetic nucleosides in murine kidneys and suggest that the functional status of CNTs may account for the optimal action of pyrimidine nucleoside analog therapeutics in humans.

MiR-202-5p Regulates Geese Follicular Selection by Targeting BTBD10 to Regulate Granulosa Cell Proliferation and Apoptosis

The regulation of granulosa cells (GCs) proliferation and apoptosis is the key step in follicular selection which determines the egg production performance of poultry. miR-202-5p has been reported to be involved in regulating the proliferation and apoptosis of mammalian ovarian GCs. However, its role in regulating the proliferation and apoptosis of goose GCs is still unknown. In the present study, the GCs of pre-hierarchical follicles (phGCs, 8-10 mm) and those of hierarchical follicles (hGCs, F2-F4) were used to investigate the role of miR-202-5p in cell proliferation and apoptosis during follicle selection. In phGCs and hGCs cultured in vitro, miR-202-5p was found to negatively regulate cell proliferation and positively regulate cell apoptosis. The results of RNA-seq showed that BTB Domain Containing 10 (BTBD10) is predicted to be a key target gene for miR-202-5p to regulate the proliferation and apoptosis of GCs. Furthermore, it is confirmed that miR-202-5p can inhibit BTBD10 expression by targeting its 3'UTR region, and BTBD10 was revealed to promote the proliferation and inhibit the apoptosis of phGCs and hGCs. Additionally, co-transfection with BTBD10 effectively prevented miR-202-5p mimic-induced cell apoptosis and the inhibition of cell proliferation. Meanwhile, miR-202-5p also remarkably inhibited the expression of Phosphatidylinositol-4,5-Bisphosphate 3-Kinase Catalytic Subunit Beta (PIK3CB) and AKT Serine/Threonine Kinase 1 (AKT1), while it was significantly restored by BTBD10. Overall, miR-202-5p suppresses the proliferation and promotes the apoptosis of GCs through the downregulation of PIK3CB/AKT1 signaling by targeting BTBD10 during follicular selection. Our study provides a theoretical reference for understanding the molecular mechanism of goose follicular selection, as well as a candidate gene for molecular marker-assisted breeding to improve the geese' egg production performance.

miRNA in Molecular Diagnostics

MicroRNAs are a class of small non-coding RNA molecules that regulate gene expression on post-transcriptional level. Their biogenesis consists of a complex series of sequential processes, and they regulate expression of many genes involved in all cellular processes. Their function is essential for maintaining the homeostasis of a single cell; therefore, their aberrant expression contributes to development and progression of many diseases, especially malignant tumors and viral infections. Moreover, they can be associated with certain states of a specific disease, obtained in the least invasive manner for patients and analyzed with basic molecular methods used in clinical laboratories. Because of this, they have a promising potential to become very useful biomarkers and potential tools in personalized medicine approaches. In this review, miRNAs biogenesis, significance in cancer and infectious diseases, and current available test and methods for their detection are summarized.

The microRNA-202 as a Diagnostic Biomarker and a Potential Tumor Suppressor

MicroRNA-202 (miR-202) is a member of the highly conserved let-7 family that was discovered in Caenorhabditis elegans and recently reported to be involved in cell differentiation and tumor biology. In humans, miR-202 was initially identified in the testis where it was suggested to play a role in spermatogenesis. Subsequent research showed that miR-202 is one of the micro-RNAs that are dysregulated in different types of cancer. During the last decade, a large number of investigations has fortified a role for miR-202 in cancer. However, its functions can be double-edged, depending on context they may be tumor suppressive or oncogenic. In this review, we highlight miR-202 as a potential diagnostic biomarker and as a suppressor of tumorigenesis and metastasis in several types of tumors. We link miR-202 expression levels in tumor types to its involved upstream and downstream signaling molecules and highlight its potential roles in carcinogenesis. Three well-known upstream long non-coding-RNAs (lncRNAs); MALAT1, NORAD, and NEAT1 target miR-202 and inhibit its tumor suppressive function thus fueling cancer progression. Studies on the downstream targets of miR-202 revealed PTEN, AKT, and various oncogenes such as metadherin (MTDH), MYCN, Forkhead box protein R2 (FOXR2) and Kirsten rat sarcoma virus (KRAS). Interestingly, an upregulated level of miR-202 was shown by most of the studies that estimated its expression level in blood or serum of cancer patients, especially in breast cancer. Reduced expression levels of miR-202 in tumor tissues were found to be associated with progression of different types of cancer. It seems likely that miR-202 is embedded in a complex regulatory network related to the nature and the sensitivity of the tumor type and therapeutic (pre)treatments. Its variable roles in tumorigenesis are mediated in part thought its oncogene effectors. However, the currently available data suggest that the involved signaling pathways determine the anti- or pro-tumorigenic outcomes of miR-202’s dysregulation and its value as a diagnostic biomarker.

EMT alterations in the solute carrier landscape uncover SLC22A10/A15 imposed vulnerabilities in pancreatic cancer

The involvement of membrane-bound solute carriers (SLCs) in neoplastic transdifferentiation processes is poorly defined. Here, we examined changes in the SLC landscape during epithelial-mesenchymal transition (EMT) of pancreatic cancer cells. We show that two SLCs from the organic anion/cation transporter family, SLC22A10 and SLC22A15, favor EMT via interferon (IFN) α and γ signaling activation of receptor tyrosine kinase-like orphan receptor 1 (ROR1) expression. In addition, SLC22A10 and SLC22A15 allow tumor cell accumulation of glutathione to support EMT via the IFNα/γ-ROR1 axis. Moreover, a pan-SLC22A inhibitor lesinurad reduces EMT-induced metastasis and gemcitabine chemoresistance to prolong survival in mouse models of pancreatic cancer, thus identifying new vulnerabilities for human PDAC.

Role of non-coding RNAs in tumor progression and metastasis in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of cancer with an overall 5-year survival rate of less than 10%. The 1-year survival rate of patients with locally advanced or metastatic disease is abysmal. The aggressive nature of cancer cells, hypovascularization, extensive desmoplastic stroma, and immunosuppressive tumor microenvironment (TME) endows PDAC tumors with multiple mechanisms of drug resistance. With no obvious genetic mutation(s) driving tumor progression or metastatic transition, the challenges for understanding the biological mechanism(s) of these processes are paramount. A better understanding of the molecular and cellular mechanisms of these processes could lead to new diagnostic tools for patient management and new targets for therapeutic intervention. microRNAs (miRNAs) are an evolutionarily conserved gene class of short non-coding regulatory RNAs. miRNAs are an extensive regulatory layer that controls gene expression at the posttranscriptional level. This review focuses on preclinical models that functionally dissect miRNA activity in tumor progression or metastatic processes in PDAC. Collectively, these studies suggest an influence of miRNAs and RNA-RNA networks in the processes of epithelial to mesenchymal cell transition and cancer cell stemness. At a cell-type level, some miRNAs mainly influence cancer cell–intrinsic processes and pathways, whereas other miRNAs predominantly act in distinct cellular compartments of the TME to regulate fibroblast and immune cell functions and/or influence other cell types’ function via cell-to-cell communications by transfer of extracellular vesicles. At a molecular level, the influence of miRNA-mediated regulation often converges in core signaling pathways, including TGF-β, JAK/STAT, PI3K/AKT, and NF-κB.

Long non-coding RNA NORAD promotes pancreatic cancer stem cell proliferation and self-renewal by blocking microRNA-202-5p-mediated ANP32E inhibition

Background

Cancer stem cells (CSCs) are key regulators in the processes of tumor initiation, progression, and recurrence. The mechanism that maintains their stemness remains enigmatic, although the role of several long noncoding RNAs (lncRNAs) has been highlighted in the pancreatic cancer stem cells (PCSCs). In this study, we first established that PCSCs overexpressing lncRNA NORAD, and then investigated the effects of NORAD on the maintenance of PCSC stemness.

Methods

Expression of lncRNA NORAD, miR-202-5p and ANP32E in PC tissues and cell lines was quantified after RNA isolation. Dual-luciferase reporter assay, RNA pull-down and RIP assays were performed to verify the interactions among NORAD, miR-202-5p and ANP32E. We then carried out gain- and loss-of function of miR-202-5p, ANP32E and NORAD in PANC-1 cell line, followed by measurement of the aldehyde dehydrogenase activity, cell viability, apoptosis, cell cycle distribution, colony formation, self-renewal ability and tumorigenicity of PC cells.

Results

LncRNA NORAD and ANP32E were upregulated in PC tissues and cells, whereas the miR-202-5p level was down-regulated. LncRNA NORAD competitively bound to miR-202-5p, and promoted the expression of the miR-202-5p target gene ANP32E thereby promoting PC cell viability, proliferation, and self-renewal ability in vitro, as well as facilitating tumorigenesis of PCSCs in vivo.

Conclusion

Overall, lncRNA NORAD upregulates ANP32E expression by competitively binding to miR-202-5, which accelerates the proliferation and self-renewal of PCSCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03052-5.

MicroRNA-1252-5p, regulated by Myb, inhibits invasion and epithelial-mesenchymal transition of pancreatic cancer cells by targeting NEDD9

MicroRNAs (miRNAs) are known to be involved in the development and progression of pancreatic cancer (PAC). The expression levels and roles of miR-1252-5p in PAC remain unclear. Quantitative real-time PCR and in situ hybridization were used to detect miR-1252-5p expression in PAC cells and human tissues. We studied the gain and loss of function of miR-1252-5p in the PAC cell lines in vitro and in vivo. The direct targets of miR-1252-5p were analyzed using public databases and a dual-luciferase reporter assay. Expression levels of miR-1252-5p are downregulated in PAC cell lines and tissue samples, and its expression is negatively associated with adverse clinical features and poor prognosis. In vitro and in vivo experiments show that miR-1252-5p overexpression inhibits the proliferation, migration, invasion, and epithelial-mesenchymal transition of PAC cells, and miR-1252-5p knockdown enhances these biological behaviors. MiR-1252-5p negatively regulates neural precursor cell expressed, developmentally downregulated 9 (NEDD9) by directly binding its 3'- untranslated region. Further mechanism research revealed that the SRC/STAT3 pathway is involved in miR-1252-5p/NEDD9 mediation of PAC's biological behaviors. We also verified that Myb inhibited miR-1252-5p by directly binding at its promoter. MiR-1252-5p may act as a tumor-suppressing miRNA in PAC and may be a potential therapeutic target for PAC patients.

Differential and unique patterns of synaptic miRNA expression in dorsolateral prefrontal cortex of depressed subjects

Altered synaptic plasticity is often associated with major depressive disorder (MDD). Disease-associated changes in synaptic functions are tightly correlated with altered microRNA (miRNA) expression. Here, we examined the role of miRNAs and their functioning at the synapse in MDD by examining miRNA processing machinery at synapse and sequencing miRNAs and analyzing their functions in synaptic and total tissue fractions obtained from dorsolateral prefrontal cortex (dlPFC) of 15 MDD and 15 matched non-psychiatric control subjects. A total of 333 miRNAs were reliably detected in the total tissue fraction. Multiple testing following the Benjamini-Hochberg false discovery rate [FDR] showed that 18 miRNAs were significantly altered (1 downregulated 4 up and 13 downregulated; p < 0.05) in MDD subjects. Out of 351 miRNAs reliably expressed in the synaptic fraction, 24 were uniquely expressed at synapse. In addition, 8 miRNAs (miR-215-5p, miR-192-5p, miR-202-5p, miR-19b-3p, miR-423-5p, miR-219a-2-3p; miR-511-5p, miR-483-5p showed significant (FDR corrected; p < 0.05) differential regulation in the synaptic fraction from dlPFC of MDD subjects. In vitro transfection studies and gene ontology revealed involvement of these altered miRNAs in synaptic plasticity, nervous system development, and neurogenesis. A shift in expression ratios (synaptic vs. total fraction) of miR-19b-3p, miR-376c-3p, miR-455-3p, and miR-337-3p were also noted in the MDD group. Moreover, an inverse relationship between the expression of precursor (pre-miR-19b-1, pre-miR-199a-1 and pre-miR-199a-2) and mature (miR-19b-3p, miR-199a-3p) miRNAs was found. Although not significantly, several miRNA processing enzymes (DROSHA [95%], DICER [17%], TARBP2 [38%]) showed increased expression patterns in MDD subjects. Our findings provide new insights into the understanding of the regulation of miRNAs at the synapse and their possible roles in MDD pathogenesis.

The Impact of Non-coding RNAs in the Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is a course of action that enables a polarized epithelial cell to undertake numerous biochemical alterations that allow it to adopt features of mesenchymal cells such as high migratory ability, invasive properties, resistance to apoptosis, and importantly higher-order formation of extracellular matrix elements. EMT has important roles in implantation and gastrulation of the embryo, inflammatory reactions and fibrosis, and transformation of cancer cells, their invasiveness and metastatic ability. Regarding the importance of EMT in the invasive progression of cancer, this process has been well studies in in this context. Non-coding RNAs (ncRNAs) have been shown to exert critical function in the regulation of cellular processes that are involved in the EMT. These processes include regulation of some transcription factors namely SNAI1 and SNAI2, ZEB1 and ZEB2, Twist, and E12/E47, modulation of chromatin configuration, alternative splicing, and protein stability and subcellular location of proteins. In the present paper, we describe the influence of ncRNAs including microRNAs and long non-coding RNAs in the EMT process and their application as biomarkers for this process and cancer progression and their potential as therapeutic targets.

Intellectual disability: dendritic anomalies and emerging genetic perspectives

Intellectual disability (ID) corresponds to several neurodevelopmental disorders of heterogeneous origin in which cognitive deficits are commonly associated with abnormalities of dendrites and dendritic spines. These histological changes in the brain serve as a proxy for underlying deficits in neuronal network connectivity, mostly a result of genetic factors. Historically, chromosomal abnormalities have been reported by conventional karyotyping, targeted fluorescence in situ hybridization (FISH), and chromosomal microarray analysis. More recently, cytogenomic mapping, whole-exome sequencing, and bioinformatic mining have led to the identification of novel candidate genes, including genes involved in neuritogenesis, dendrite maintenance, and synaptic plasticity. Greater understanding of the roles of these putative ID genes and their functional interactions might boost investigations into determining the plausible link between cellular and behavioral alterations as well as the mechanisms contributing to the cognitive impairment observed in ID. Genetic data combined with histological abnormalities, clinical presentation, and transgenic animal models provide support for the primacy of dysregulation in dendrite structure and function as the basis for the cognitive deficits observed in ID. In this review, we highlight the importance of dendrite pathophysiology in the etiologies of four prototypical ID syndromes, namely Down Syndrome (DS), Rett Syndrome (RTT), Digeorge Syndrome (DGS) and Fragile X Syndrome (FXS). Clinical characteristics of ID have also been reported in individuals with deletions in the long arm of chromosome 10 (the q26.2/q26.3), a region containing the gene for the collapsin response mediator protein 3 (CRMP3), also known as dihydropyrimidinase-related protein-4 (DRP-4, DPYSL4), which is involved in dendritogenesis. Following a discussion of clinical and genetic findings in these syndromes and their preclinical animal models, we lionize CRMP3/DPYSL4 as a novel candidate gene for ID that may be ripe for therapeutic intervention.

MicroRNA-202 suppresses glycolysis of pancreatic cancer by targeting hexokinase 2

Purpose: Various studies have identified miR-202 critically participated in the development of different cancers. However, the potential mechanisms underlying the carcinogenesis of pancreatic cancer (PC) still remains elusive. Methods: In the study, cell proliferation assay, colony formation assay, EdU incorporation assay, Luciferase reporter assay, lactate production, glucose consumption assay, real-time PCR and western blot were used to investigate the mechanism of hexokinase 2 (HK2) regulated by miR-202 in pancreatic cancer in vitro and in vivo. Results: Here we found that miR-202 was decreased in the PC tissues, and its low expression was correlated with a poor prognosis of PC patients. Overexpression of miR-202 in PC cells reduced cell proliferation and tumorigenesis by impairing glycolysis, while downregulation of miR-202 promoted the cells proliferative capacity. Mechanically, we demonstrated that HK2, an enzyme that catalyzes the irreversible rate-limiting step of glycolysis, as the direct target of miR-202. Overexpression of miR-202 suppressed both the mRNA and protein levels of HK2, whereas re-introduction of HK2 abrogated miR-202-mediated glycolytic inhibition. In addition, the expression of miR-202 was negatively associated with HK2 level in a cohort of PC tissues. Conclusion: Our findings validate the mechanism that miR-202 reprograms the metabolic process to promote PC progression, thus providing potential prognostic predictors for PC patients.

LncRNA OIP5-AS1 promotes the malignancy of pancreatic ductal adenocarcinoma via regulating miR-429/FOXD1/ERK pathway

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC), a subtype of pancreatic cancer, is a malignant tumor with unfavorable prognosis. Despite accumulating researches have made efforts on finding novel therapeutic methods for this disease, the underlying mechanism of long non-coding RNAs (lncRNAs) remains elusive. OIP5 antisense RNA 1 (OIP5-AS1) has been reported to play important role in the occurrence and development of multiple human cancers. This study was aimed at unveiling the regulatory role of OIP5-AS1 in PDAC.

METHODS

RT-qPCR analysis revealed the OIP5-AS1 expression in PDAC tissues and adjacent normal ones. Kaplan-Meier method was applied to analyze the overall survival of patients with high or low level of OIP5-AS1. Gain- or loss-of function assays were performed to assess the effects of OIP5-AS1 knockdown on cell functions, including proliferation, migration and EMT process. Mechanism experiments, such as luciferase reporter and RNA pull-down assays proved the interaction between OIP5-AS1 and miR-429 as well as that between miR-429 and FOXD1.

RESULTS

OIP5-AS1 was up-regulated in PDAC tissues and cell lines, and high level of OIP5-AS1 indicated poor prognosis in PDAC patients. OIP5-AS1 knockdown hindered cell proliferation, migration and epithelial-mesenchymal transition (EMT) process, while overexpression of OIP5-AS1 caused the opposite results. OIP5-AS1 activated ERK pathway through up-regulating forkhead box D1 (FOXD1) expression by sponging miR-429. Furthermore, OIP5-AS1 facilitated cell growth in vivo.

CONCLUSION

OIP5-AS1 exerted oncogenic function in PDAC cells through targeting miR-429/FOXD1/ERK pathway.

Mammalian STE20‑like kinase 1 regulates pancreatic cancer cell survival and migration through Mfn2‑mediated mitophagy

Mammalian STE20-like kinase 1 (MST1) plays an important role in pancreatic cancer progression, but its downstream targets are still unknown. In the present study, our results indicated that MST1 expression was significantly downregulated in pancreatic cancer cell lines (PANC‑1, BxPC‑3 and HPAC) compared with that in the normal ductal epithelial cell line (hTERT‑HPNE). Moreover, MST1 overexpression in PANC‑1 cells led to increased apoptosis as determined by MTT and TUNEL assays and inhibited cellular migration. Mechanistically, upregulation of MST1 expression caused mitochondrial dysfunction, decreased ATP production, and activation of the mitochondrial‑dependent apoptotic pathway via inhibition of mitofusin 2 (Mfn2)‑mediated mitophagy, which ultimately resulted in increased cellular apoptosis and decreased cellular migration. Collectively, the present study demonstrated that MST1 may regulate pancreatic cancer PANC‑1 cell survival, invasion and migration through Mfn2‑mediated mitophagy, laying the foundation for the exploration of novel therapeutic targets for pancreatic cancer.

Epithelial-Mesenchymal Transition: Role in Cancer Progression and the Perspectives of Antitumor Treatment

About 90% of all malignant tumors are of epithelial nature. The epithelial tissue is characterized by a close interconnection between cells through cell-cell interactions, as well as a tight connection with the basement membrane, which is responsible for cell polarity. These interactions strictly determine the location of epithelial cells within the body and are seemingly in conflict with the metastatic potential that many cancers possess (the main criteria for highly malignant tumors). Tumor dissemination into vital organs is one of the primary causes of death in patients with cancer. Tumor dissemination is based on the so-called epithelial-mesenchymal transition (EMT), a process when epithelial cells are transformed into mesenchymal cells possessing high mobility and migration potential. More and more studies elucidating the role of the EMT in metastasis and other aspects of tumor progression are published each year, thus forming a promising field of cancer research. In this review, we examine the most recent data on the intracellular and extracellular molecular mechanisms that activate EMT and the role they play in various aspects of tumor progression, such as metastasis, apoptotic resistance, and immune evasion, aspects that have usually been attributed exclusively to cancer stem cells (CSCs). In conclusion, we provide a detailed review of the approved and promising drugs for cancer therapy that target the components of the EMT signaling pathways.

Pancreatic Ductal Adenocarcinoma: MicroRNAs Affecting Tumor Growth and Metastasis in Preclinical In Vivo Models

Patients with pancreatic ductal adenocarcinoma have a dismall prognosis because at the time of diagnosis, in the vast majority of patients the tumor has already disseminated to distant organs and the therapeutic benefit of approved agents such as gemcitabine is limited. Therefore, the identification and preclinical and clinical validation of therapeutic agents covering new targets is of paramount importance. In this review we have summarized microRNAs and corresponding targets which affect growth and metastasis of pancreatic tumors in preclinical mouse in vivo models. We identified four up-regulated and 16 down-regulated miRs in PDAC in comparison to corresponding normal tissues. Three sub-categories of miRs have emerged: miRs affecting tumor growth and miRs with an impact on both, tumor growth and metastasis or metastasis only. Finally, we discuss technical and therapeutic aspects of miR-related therapeutic agents for the treatment of pancreatic ductal adenocarcinoma.

Transactivation of miR-202-5p by Steroidogenic Factor 1 (SF1) Induces Apoptosis in Goat Granulosa Cells by Targeting TGFβR2

MicroRNAs play key roles during ovary development, with emerging evidence suggesting that miR-202-5p is specifically expressed in female animal gonads. Granulosa cells (GCs) are somatic cells that are closely related to the development of female gametes in mammalian ovaries. However, the biological roles of miR-202-5p in GCs remain unknown. Here, we show that miR-202-5p is specifically expressed in GCs and accumulates in extracellular vesicles (EVs) from large growth follicles in goat ovaries. In vitro assays showed that miR-202-5p induced apoptosis and suppressed the proliferation of goat GCs. We further revealed that miR-202-5p is a functional miRNA that targets the transforming growth factor-beta type II receptor (TGFβR2). MiR-202-5p attenuated TGF-β/SMAD signaling through the degradation of TGFβR2 at both the mRNA and protein level, decreasing p-SMAD3 levels in GCs. Moreover, we verified that steroidogenic factor 1 (SF1) is a transcriptional factor that binds to the promoters of miR-202 and cytochrome P450 family 19 subfamily A member 1 (CYP19A1) through luciferase reporter and chromatin immunoprecipitation (ChIP) assays. That contributed to positive correlation between miR-202-5p and CYP19A1 expression and estradiol (E2) release. Furthermore, SF1 repressed TGFβR2 and p-SMAD3 levels in GCs through the transactivation of miR-202-5p. Taken together, these results suggest a mechanism by which miR-202-5p regulates canonical TGF-β/SMAD signaling through targeting TGFβR2 in GCs. This provides insight into the transcriptional regulation of miR-202 and CYP19A1 during goat ovarian follicular development.

MiR-202-3p Inhibits Foam Cell Formation and is Associated with Coronary Heart Disease Risk in a Chinese Population

A previous study and a gene-annotation enrichment analysis for potential targets of the microRNA miR-202-3p both suggest that this microRNA might be implicated in cardiovascular and metabolic diseases. In the present study, the role of miR-202-3p in the pathogenesis of coronary heart disease (CHD) was explored. We conduct a case-control study to detect the expression levels of miR-202-3p in peripheral blood cells and found that miR-202-3p expression was significantly higher in CHD cases than in controls (P < 0.001). miR-202-3p levels were negatively correlated with platelet distribution width (r = -0.348, P = 0.002) and mean platelet volume (r = -0.29, P = 0.01). Further functional analyses suggested that stimulation with oxidized low-density lipoprotein (ox-LDL) induced miR-202-3p expression, and that this microRNA suppressed the formation of ox-LDL-induced macrophage foam cells derived from THP-1 cells in a feedback manner. In addition, miR-202-3p overexpression modulated the expression of several key genes involved in foam cell formation, including that of ABCG4, NCEH1I, and SCARB2. In summary, miR-202-3p was associated with CHD, exerting a protective role against CHD by feedback suppression of ox-LDL-induced macrophage foam cell formation.

lncRNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 Promotes Proliferation and Invasion of Non-Small Cell Lung Cancer Cells via Down-Regulating miR-202 Expression

Objective

Accumulating evidences indicate that long non-coding RNAs (lncRNAs) play key roles in cancer. This study aims to clarify role of the metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in non-small cell lung cancer (NSCLC) and uncover the underlying mechanisms.

Materials and Methods

In this experimental study, MALAT1 and miR-202 expression in tissues and cell lines were detected using quantitative real time polymerase chain reaction (qRT-PCR) assay. Cell transfection was conducted using Lipofectamine 3000. Cell proliferation was determined with CCK-8 assay. MMP2 and MMP9 expressions were measured with Western blot. Cell invasive ability was evaluated by Transwell assay. Starbase 2.0 tool was used to predict targets of MALAT1. Dual luciferase reporter assay, RNA-binding protein immunoprecipitation assay and RNA pull-down assay were conducted to confirm the potential direct interaction between MALAT1 and miR-202.

Results

MALAT1 was overexpressed in NSCLC samples and cell lines. High expression of MALAT1 was related to large tumor size (>3 cm), poor histological grade, advanced cancer and tumor metastasis in NSCLC. In vitro assays exhibited that knockdown of MALAT1 remarkably decreased A549 cell growth and invasion capacity, while overexpression of MALAT1 significantly enhanced NCI-H292 cell proliferation and invasion ability. Next, we verified that MALAT1 could act as a competing endogenous RNA (ceRNA) by sponging miR-202 in NSCLC and there is a negative correlation between MALAT1 and miR-202. Besides, overexpression of miR-202 inhibited cell proliferation and invasive ability in MALAT1-overexpressed cells.

Conclusion

This study demonstrated that lncRNA-MALAT1 gets involved in NSCLC progression by targeting miR- 202, indicating that MALAT1 may serve as a novel therapeutic target for NSCLC treatment.

Prognostic value of transforming growth factor beta receptor 1 polymorphisms in patients with oral cancer

OBJECTIVE

To investigate possible associations between disease-specific survival (DSS) of oral cancer and single nucleotide polymorphisms (SNPs) in transforming growth factor beta receptor 1 (TGFBR1).

METHODS

Using iPLEX Sequenom MassARRAY platform, three SNPs in TGFBR1 gene were genotyped in 356 newly diagnosed patients with histologically confirmed primary oral cancer. Demographic and clinical information of all cases were obtained from face-to-face interviews and electronic medical records, and telephone interviews were carried out every 6 months to timely gain follow-up data. Univariate and multivariate Cox proportional hazards model were used to assess the association between the polymorphisms of tagging loci and DSS of oral cancer.

RESULTS

TGFBR1 rs33438 polymorphism was protective against death of oral cancer in codominant (AG vs AA: HR = 0.55, 95% CI = 0.35-0.88) and dominant (GG + AG vs AA: HR = 0.57, 95% CI = 0.38-0.87) models. Moreover, better DSS was particularly significant in radiotherapy patients who carrying GG + AG genotype. There also existed a positive multiplicative interaction on DSS between the polymorphism of TGFBR1 rs334348 and radiotherapy (P = .001). Not any associations between TGFBR1 rs334354 or rs3739798 polymorphism and DSS were observed.

CONCLUSIONS

This preliminary prospective study suggests that polymorphism of TGFBR1 rs334348 may act as a potentially independent factor and novel genetic biomarker to predict oral cancer DSS especially for patients with radiotherapy. A much more extensive investigation will need to confirm our findings.

ssc-miR-204 regulates porcine preadipocyte differentiation and apoptosis by targeting TGFBR1 and TGFBR2

MicroRNAs (miRNAs) take part in a variety of biological processes by regulating target genes. Transforming growth factor β receptor 1 (TGFBR1) and TGFBR2 are crucial members of the TGF-β family and are serine/threonine kinase receptors. The aim of this study was to explore the functions of ssc-miR-204 in porcine preadipocyte differentiation and apoptosis with regard to the TGFβ/Smad pathway. We identified miRNAs predicted to target TGFBR1 and TGFBR2 using a database and selected ssc-miR-204 as a candidate miRNA. ssc-miR-204 overexpression dramatically reduced the levels of TGFBR1 and TGFBR2. However, after transfection with ssc-miR-204 inhibitor, TGFBR1 and TGFBR2 levels were dramatically increased. ssc-miR-204 overexpression dramatically promoted porcine preadipocyte differentiation and apoptosis. After transfection with ssc-miR-204 inhibitor, porcine preadipocyte differentiation and apoptosis were dramatically inhibited. After transfection with ssc-miR-204 mimics, Smad2, Smad3, Smad4, p-Smad2, and p-Smad3 protein levels significantly decreased, and adipogenesis was regulated by inhibiting the TGF-β/Smad3 signaling pathway. Taken together, these results verified that ssc-miR-204 regulates porcine preadipocyte differentiation and apoptosis by targeting TGFBR1 and TGFBR2.

MiR-202 inhibits the proliferation and invasion of colorectal cancer by targeting UHRF1

The purpose of this study was to investigate the expression of microRNA-202 (miR-202) and its role in colorectal cancer (CRC) in vivo and in vitro. We examined the expression of miR-202 in CRC tissues by quantitative real-time PCR (qRT-PCR) assay. Lentiviral vectors were constructed to overexpress or inhibit the expression of miR-202 in the CRC cell lines HCT116 and SW480 to determine its effects on cell invasion and proliferation. We found that overexpression of miR-202 significantly inhibited the proliferation and invasion of HCT116 cells. MiRNA target gene prediction, dual luciferase assay, and western blot analysis demonstrated that miR-202 regulated ubiquitin-like with PHD and RING finger domain 1 (UHRF1) expression in both cell lines. The effect of miR-202 on cell proliferation and invasion was partially reversed by activating the expression of UHRF1. Furthermore, miR-202 induced tumor formation in HCT116 xenograft BALB/c nude mice. Mice vaccinated with miR-202-overexpressing cells had smaller tumors and lower UHRF1 expression than the control group. These results indicate the possibility that miR-202 is under-expressed in CRC tissues, and that miR-202 inhibits the proliferation and invasion of CRC via targeting UHRF1. MiR-202 is a potential therapeutic target for CRC.

Epithelial-Mesenchymal Plasticity in Organotropism Metastasis and Tumor Immune Escape

Most cancer deaths are due to metastasis, and almost all cancers have their preferential metastatic organs, known as “organotropism metastasis”. Epithelial-mesenchymal plasticity has been described as heterogeneous and dynamic cellular differentiation states, supported by emerging experimental evidence from both molecular and morphological levels. Many molecular factors regulating epithelial-mesenchymal plasticity have tissue-specific and non-redundant properties. Reciprocally, cellular epithelial-mesenchymal plasticity contributes to shaping organ-specific pre-metastatic niche (PMN) including distinct local immune landscapes, mainly through secreted bioactive molecular factors. Here, we summarize recent progress on the involvement of tumor epithelial-mesenchymal plasticity in driving organotropic metastasis and regulating the function of different immune cells in organ-specific metastasis.

YY1 regulates cancer cell immune resistance by modulating PD-L1 expression

Recent advances in the treatment of various cancers have resulted in the adaptation of several novel immunotherapeutic strategies. Notably, the recent intervention through immune checkpoint inhibitors has resulted in significant clinical responses and prolongation of survival in patients with several therapy-resistant cancers (melanoma, lung, bladder, etc.). This intervention was mediated by various antibodies directed against inhibitory receptors expressed on cytotoxic T-cells or against corresponding ligands expressed on tumor cells and other cells in the tumor microenvironment (TME). However, the clinical responses were only observed in a subset of the treated patients; it was not clear why the remaining patients did not respond to checkpoint inhibitor therapies. One hypothesis stated that the levels of PD-L1 expression correlated with poor clinical responses to cell-mediated anti-tumor immunotherapy. Hence, exploring the underlying mechanisms that regulate PD-L1 expression on tumor cells is one approach to target such mechanisms to reduce PD-L1 expression and, therefore, sensitize the resistant tumor cells to respond to PD-1/PD-L1 antibody treatments. Various investigations revealed that the overexpression of the transcription factor Yin Yang 1 (YY1) in most cancers is involved in the regulation of tumor cells' resistance to cell-mediated immunotherapies. We, therefore, hypothesized that the role of YY1 in cancer immune resistance may be correlated with PD-L1 overexpression on cancer cells. This hypothesis was investigated and analysis of the reported literature revealed that several signaling crosstalk pathways exist between the regulations of both YY1 and PD-L1 expressions. Such pathways include p53, miR34a, STAT3, NF-kB, PI3K/AKT/mTOR, c-Myc, and COX-2. Noteworthy, many clinical and pre-clinical drugs have been utilized to target these above pathways in various cancers independent of their roles in the regulation of PD-L1 expression. Therefore, the direct inhibition of YY1 and/or the use of the above targeted drugs in combination with checkpoint inhibitors should result in enhancing the cell-mediated anti-tumor cell response and also reverse the resistance observed with the use of checkpoint inhibitors alone.

DANCR-mediated microRNA-665 regulates proliferation and metastasis of cervical cancer through the ERK/SMAD pathway

Emerging evidence has indicated that microRNAs (miRNAs) play an important role in cervical cancer (CC). However, the role of miRNA (miR)-665 in cervical cancer remains unclear. The aim of the present study was to investigate the potential functions of miR-665 in CC and to identify the underlying mechanisms of action. Herein, we show that miR-665 was downregulated in CC tissues and cell lines, which is negatively correlated with tumor size, distant metastasis, advanced TNM stage and poor prognosis. Functionally, miR-665 inhibited cell proliferation, migration and invasion and resistance of cisplatin for CC cells, as well as tumor growth. We validated that transforming growth factor beta receptor 1 (TGFBR1) was a direct target of miR-665 and mediated the ERK/SMAD pathway. In addition, we identified miR-665 as the competing endogenous RNA for long noncoding (lnc)-DANCR. These observations suggested that lnc-DANCR-mediated miR-665 downregulation regulates the malignant phenotype of CC cells by targeting TGFBR1 through the ERK/SMAD pathway, which may present a pathway for novel therapeutic stratagems for CC therapy.

Interplay between epigenetic abnormalities and deregulated expression of microRNAs in cancer

Epigenetic abnormalities and aberrant expression of non-coding RNAs are two emerging features of cancer cells, both of which are responsible for deregulated gene expression. In this review, we describe the interplay between the two. Specific themes include epigenetic silencing of tumor suppressor miRNAs, epigenetic activation of oncogenic miRNAs, epigenetic aberrations caused by miRNAs, and naturally occurring compounds which modulate miRNA expression through epigenetic mechanisms.

Epigenomics of Pancreatic Cancer: A Critical Role for Epigenome-Wide Studies

Several challenges present themselves when discussing current approaches to the prevention or treatment of pancreatic cancer. Up to 45% of the risk of pancreatic cancer is attributed to unknown causes, making effective prevention programs difficult to design. The most common type of pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC), is generally diagnosed at a late stage, leading to a poor prognosis and 5-year survival estimate. PDAC tumors are heterogeneous, leading to many identified cell subtypes within one patient’s primary tumor. This explains why there is a high frequency of tumors that are resistant to standard treatments, leading to high relapse rates. This review will discuss how epigenetic technologies and epigenome-wide association studies have been used to address some of these challenges and the future promises these approaches hold.

MiR-106a-5p promotes 5-FU resistance and the metastasis of colorectal cancer by targeting TGFβR2

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths. 5-Fluorouracil (5-FU)-based chemotherapy has always been the first-line treatment. However, development of 5-FU resistance seriously affects its curative effect. The aim of this study was to elucidate the molecular mechanisms of 5-FU resistance through miR-106a-5p in CRC.

METHODS

Colorectal cancer tissues were collected to analyze miR-106a-5p and TGFβR2 expressions by qPCR. Functional experiments for evaluating cell survival and metastasis were conducted to observe the biological effects of miR-106a-5p and TGFβR2. The cell survival rate was calculated using an MTT assay; the metastasis was confirmed with a Transwell invasion assay and Western blotting, which we used to measure the expression levels of the epithelial-mesenchymal transition (EMT) markers E-cadherin and vimentin. The combination of miR-106a to TGFβR2 was predicted using Targetscan, and confirmed through the construction of the luciferase reporter plasmid pGL3-basic. The interplay between miR-106a-5p and TGFβR2 was tested with qPCR and Western blotting. A Spearman rank analysis was employed to verify the correlation of miR-106a-5p and TGFβR2 expressions.

RESULTS

MiR-106a-5p was up-regulated and TGFβR2 was down-regulated in 5-FU resistant CRC tissues and HT-29 cells. MiR-106a-5p promoted cell survival and suppressed the apoptosis rate and caspase 3 activity. Additionally, cell invasion was promoted by miR-106a-5p overexpression in the HT-29 cells and was inhibited by miR-106a-5p knockdown in the 5-FU resistant HT-29 cells; miR-106a-5p overexpression contributed to migration by increasing vimentin expression and by decreasing E-cadherin expression in the HT-29 cells; miR-106a-5p functioned by directly binding to TGFβR2. The TGFβR2 knockdown conferred chemoresistance of 5-FU and metastasis in 5-FU resistant HT-29 cells, and TGFβR2 overexpression reduced cell survival, invasion numbers, vimentin expression, and increased the cell apoptosis rate and caspase 3 activity in 5-FU resistant HT-29 cells. Also, miR-106a-5p negatively regulated TGFβR2 in a linear correlation way in the CRC tissues.

CONCLUSION

The up-regulation of miR-106a-5p contributes to the pathomechanism of colorectal cancer by promoting 5-FU resistance and metastasis via inhibiting target TGFβR2. Our findings provide new promising ways for the clinical application of the TGFβR2-miR-106a axis in clinical chemotherapy for 5-FU resistant colorectal cancer.

MicroRNA-98-5p inhibits proliferation and metastasis in non-small cell lung cancer by targeting TGFBR1

MicroRNAs (miRNAs or miRs) have recently emerged as key regulators of various types of cancer, including non‑small cell lung cancer (NSCLC). The disrupted expression of miRNAs is associated with tumorigenesis and metastasis; however, the underlying mechanisms remain unclear. In this study, we demonstrate that miR‑98‑5p is downregulated in NSCLC and that miR‑98‑5p deficiency is associated with an advanced clinical stage and metastasis. A dual‑luciferase reporter assay was performed to confirm that transforming growth factor beta receptor 1 (TGFBR1), a key stimulator of tumor proliferation and metastasis, was a direct target of miR‑98‑5p. miR‑98‑5p overexpression resulted in the downregulation of TGFBR1 and the suppression of the viability, proliferation, migration and invasion of A549 and H1299 cells. Furthermore, miR‑98‑5p was demonstrated to be an efficient suppressor of tumor growth in an A549 subcutaneous xenograft tumor mouse model. Finally, miR‑98‑5p overexpression exerted a significant anti‑metastatic effect in a mouse model of pulmonary metastasis. On the whole, the results of the present study suggest that miR‑98‑5p/TGFBR1 may serve as promising targets for NSCLC therapy.

miR-202 acts as a potential tumor suppressor in breast cancer

Breast cancer affects ~10% of women worldwide and is responsible for ~12% of all cancer-associated mortalities. Breast cancer is more prone to metastasis compared with other types of cancer. Up to 5% of patients with breast cancer present with incurable metastasis and an additional 10-15% of patients develop metastases within 3 years of their initial diagnosis. MicroRNAs (miRNAs) are short RNAs, 21-25 nucleotides in length, that have been shown to significantly affect gene expression. In total >2,000 miRNAs have been identified and specific miRNAs have been revealed to be associated with cancer. In the present study, we observed that the majority of breast cancer specimens collected expressed low levels of miR-202 compared with adjacent tissues and normal cell lines. Mechanistic investigations identified KRAS as a potential target gene of miR-202 and it was demonstrated that miR-202 exerted its tumor-suppressive effects by regulating the expression of KRAS in breast cancer cells. Functional assays revealed that miR-202 significantly reduced cell proliferation, migration and invasion in vitro. In summary, these results indicate the function of miR-202 in breast cancer progression and suggest that its use within breast cancer therapy is promising.

lncRNA NORAD Contributes to Colorectal Cancer Progression by Inhibition of miR-202-5p

Previous study indicates that long noncoding RNA NORAD could serve as a competing endogenous RNA to pancreatic cancer metastasis. However, its role in colorectal cancer (CRC) needs to be investigated. In the present study, we found that the expression of NORAD was significantly upregulated in CRC tissues. Furthermore, the expression of NORAD was positively related with CRC metastasis and patients’ poor prognosis. Knockdown of NORAD markedly inhibited CRC cell proliferation, migration, and invasion but induced cell apoptosis in vitro. In vivo experiments also indicated an inhibitory effect of NORAD on tumor growth. Mechanistically, we found that NORAD served as a competing endogenous RNA for miR-202-5p. We found that there was an inverse relationship between the expression of NORAD and miR-202-5p in CRC tissues. Moreover, overexpression of miR-202-5p in SW480 and HCT116 cells significantly inhibited cellular proliferation, migration, and invasion. Taken together, our study demonstrated that the NORAD/miR-202-5p axis plays a pivotal function on CRC progression.

miR-206 Inhibits Cell Proliferation, Migration, and Invasion by Targeting BAG3 in Human Cervical Cancer

miR-206 and Bcl-2-associated athanogene 3 (BAG3) have been suggested as important regulators in various cancer types. However, the biological role of miR-206 and BAG3 in cervical cancer (CC) remains unclear. We investigated the expressions and mechanisms of miR-206 and BAG3 in CC using in vitro and in vivo assays. In the present study, miR-206 expression was expressed at a lower level in CC tissues and cells than adjacent normal tissues and NEECs. By contrast, BAG3 mRNA and protein were expressed at higher levels in CC tissues and cells. Furthermore, miR-206 overexpression repressed cell proliferation, migration, and invasion in vitro, and the 3′-untranslated region (3′-UTR) of BAG3 was a direct target of miR-206. miR-206 overexpression also inhibited EGFR, Bcl-2, and MMP2/9 protein expression, but promoted Bax protein expression. Besides, BAG3 overexpression partially abrogated miR-206-inhibited cell proliferation and invasion, while BAG3 silencing enhanced miR-206-mediated inhibition. In vivo assay revealed that miR-206 repressed tumor growth in nude mice xenograft model. In conclusion, miR-206 inhibits cell proliferation, migration, and invasion by targeting BAG3 in human CC. Thus, miR-206-BAG3 can be used as a useful target for CC.

Unveiling massive numbers of cancer-related urinary-microRNA candidates via nanowires

Analyzing microRNAs (miRNAs) within urine extracellular vesicles (EVs) is important for realizing miRNA-based, simple, and noninvasive early disease diagnoses and timely medical checkups. However, the inherent difficulty in collecting dilute concentrations of EVs (<0.01 volume %) from urine has hindered the development of these diagnoses and medical checkups. We propose a device composed of nanowires anchored into a microfluidic substrate. This device enables EV collections at high efficiency and in situ extractions of various miRNAs of different sequences (around 1000 types) that significantly exceed the number of species being extracted by the conventional ultracentrifugation method. The mechanical stability of nanowires anchored into substrates during buffer flow and the electrostatic collection of EVs onto the nanowires are the two key mechanisms that ensure the success of the proposed device. In addition, we use our methodology to identify urinary miRNAs that could potentially serve as biomarkers for cancer not only for urologic malignancies (bladder and prostate) but also for nonurologic ones (lung, pancreas, and liver). The present device concept will provide a foundation for work toward the long-term goal of urine-based early diagnoses and medical checkups for cancer.