BRM transcriptionally regulates miR-302a-3p to target SOCS5/STAT3 signaling axis to potentiate pancreatic cancer metastasis

PHD finger protein 10 promotes cell proliferation by regulating CD44 transcription in gastric cancer

PHD finger protein 10 (PHF10) plays an important role in the tumorigenesis of gastric cancer (GC). However, clinical significance and underlying molecular mechanisms about PHF10 is unclear. In the article, it suggested that PHF10 involved in tumor progression and metastasis based on the analysis of datasets and 190 cases of tumor tissues in GC. And PHF10 provided the diagnostic value with areas under the receiver operating characteristics curve of 0.71 ± 0.069. Then we established GC cell lines MKN28 with PHF10 overexpression and SGC7901 with PHF10 knockdown. CCK8 assay and tumor xenograft experiment showed that upregulation of PHF10 could promote MKN28 cell proliferation, while PHF10 knockdown would inhibit the proliferation of SGC7901 in vitro and vivo. Nevertheless, PHF10 could upregulate CD44 mRNA expression by acting on its promoter at the level of transcription. This effect could be associated with BRG, BAF155 and SNF5, which were conserved subunits of switch/sucrose non-fermentable (SWI/SNF) complex. In conclusion, PHF10 targeting CD44 plays an essential part during the modulation of proliferation of GC cell and may offer a new therapeutic direction for GC.

Silencing lncRNA-DARS-AS1 suppresses nonsmall cell lung cancer progression by stimulating miR-302a-3p to inhibit ACAT1 expression

Long noncoding RNAs (LncRNAs) have been gaining attention as potential therapeutic targets for lung cancer. In this study, we investigated the expression and biological behavior of lncRNA DARS-AS1, its predicted interacting partner miR-302a-3p, and ACAT1 in nonsmall cell lung cancer (NSCLC). The transcript level of DARS-AS1, miR-302a-3p, and ACAT1 was analyzed using qRT-PCR. Endogenous expression of ACAT1 and the expression of-and changes in-AKT/ERK pathway-related proteins were determined using western blotting. MTS, Transwell, and apoptosis experiments were used to investigate the behavior of cells. The subcellular localization of DARS-AS1 was verified using FISH, and its binding site was verified using dual-luciferase reporter experiments. The binding of DARS-AS1 to miR-302a-3p was verified using RNA co-immunoprecipitation. In vivo experiments were performed using a xenograft model to determine the effect of DARS-AS1 knockout on ACAT1 and NSCLC. lncRNA DARS-AS1 was upregulated in NSCLC cell lines and tissues and the expression of lncRNA DARS-AS1 was negatively correlated with survival of patients with NSCLC. Knockdown of DARS-AS1 inhibited the malignant behaviors of NSCLC via upregulating miR-302a-3p. miR-302a-3p induced suppression of malignancy through regulating oncogene ACAT1. This study demonstrates that the DARS-AS1-miR-302a-3p-ACAT1 pathway plays a key role in NSCLC.

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.

Noncoding RNAs as regulators of STAT3 pathway in gastrointestinal cancers: Roles in cancer progression and therapeutic response

Gastrointestinal (GI) tumors (cancers of the esophagus, gastric, liver, pancreas, colon, and rectum) contribute to a large number of deaths worldwide. STAT3 is an oncogenic transcription factor that promotes the transcription of genes associated with proliferation, antiapoptosis, survival, and metastasis. STAT3 is overactivated in many human malignancies including GI tumors which accelerates tumor progression, metastasis, and drug resistance. Research in recent years demonstrated that noncoding RNAs (ncRNAs) play a major role in the regulation of many signaling pathways including the STAT3 pathway. The major types of endogenous ncRNAs that are being extensively studied in oncology are microRNAs, long noncoding RNAs, and circular RNAs. These ncRNAs can either be tumor-promoters or tumor-suppressors and each one of them imparts their activity via different mechanisms. The STAT3 pathway is also tightly modulated by ncRNAs. In this article, we have elaborated on the tumor-promoting role of STAT3 signaling in GI tumors. Subsequently, we have comprehensively discussed the oncogenic as well as tumor suppressor functions and mechanism of action of ncRNAs that are known to modulate STAT3 signaling in GI cancers.

Mutual Regulation of ncRNAs and Chromatin Remodeling Complexes in Normal and Pathological Conditions

Chromatin remodeling is the one of the main epigenetic mechanisms of gene expression regulation both in normal cells and in pathological conditions. In recent years, a growing number of investigations have confirmed that epigenetic regulators are tightly connected and form a comprehensive network of regulatory pathways and feedback loops. Genes encoding protein subunits of chromatin remodeling complexes are often mutated and change their expression in diseases, as well as non-coding RNAs (ncRNAs). Moreover, different mechanisms of their mutual regulation have already been described. Further understanding of these processes may help apply their clinical potential for establishment of the diagnosis, prognosis, and treatment of the diseases. The therapeutic targeting of the chromatin structure has many limitations because of the complexity of its regulation, with the involvement of a large number of genes, proteins, non-coding transcripts, and other intermediary molecules. However, several successful strategies have been proposed to target subunits of chromatin remodeling complexes and genes encoding them, as well as the ncRNAs that regulate the operation of these complexes and direct them to the target gene regions. In our review, we focus on chromatin remodeling complexes and ncRNAs, their mutual regulation, role in cellular processes and potential clinical application.

SWI/SNF complexes and cancers

Epigenetics refers to the study of genetic changes that can affect gene expression without altering the underlying DNA sequence, including DNA methylation, histone modification, chromatin remodelling, X chromosome inactivation and non-coding RNA regulation. Of these, DNA methylation, histone modification and chromatin remodelling constitute the three classical modes of epigenetic regulation. These three mechanisms alter gene transcription by adjusting chromatin accessibility, thereby affecting cell and tissue phenotypes in the absence of DNA sequence changes. In the presence of ATP hydrolases, chromatin remodelling alters the structure of chromatin and thus changes the transcription level of DNA-guided RNA. To date, four types of ATP-dependent chromatin remodelling complexes have been identified in humans, namely SWI/SNF, ISWI, INO80 and NURD/MI2/CHD. SWI/SNF mutations are prevalent in a wide variety of cancerous tissues and cancer-derived cell lines as discovered by next-generation sequencing technologies.. SWI/SNF can bind to nucleosomes and use the energy of ATP to disrupt DNA and histone interactions, sliding or ejecting histones, altering nucleosome structure, and changing transcriptional and regulatory mechanisms. Furthermore, mutations in the SWI/SNF complex have been observed in approximately 20% of all cancers. Together, these findings suggest that mutations targeting the SWI/SNF complex may have a positive impact on tumorigenesis and cancer progression.

Dexmedetomidine promotes ferroptotic cell death in gastric cancer via hsa_circ_0008035/miR-302a/E2F7 axis

Dexmedetomidine (DEX), a common anesthetic, has significant effects on the biological features of cancer cells. Although numerous studies have been published on the impact of DEX on the biological characteristics of GC cells, the mechanism remains unknown. This study aimed to explore the effect of DEX on the biological properties of GC cells. DEX suppressed the viability and increased the apoptosis of GC cells in vitro and inhibited tumor growth in vivo. Besides, DEX raised the levels of reactive oxygen species (ROS) and iron, but decreased the levels of glutathione (GSH), glutathione peroxidase 4 (GPX4), and solute carrier family 7 member 11 (SLC7A11) in GC cells, which were abolished by Ferrostatin-1 (the inhibitor of ferroptosis) treatment. In addition, the level of circ0008035 and E2F7 were downregulated, but miR-302a level was upregulated in DEX-treated GC cells. Circ0008035 increased the expression of E2F2 by acting as a sponge for miR-302a. Circ0008035 inhibited DEX-induced ferroptotic cell death in GC cells, which was reversed by miR-302a overexpression or E2F7 reduction. Taken together, DEX mediated ferroptotic cell death in GC through regulating the circ0008035/miR-302a/E2F7 axis, suggesting a feasible therapy option for GC.

miR-302a-3p Promotes Radiotherapy Sensitivity of Hepatocellular Carcinoma by Regulating Cell Cycle via MCL1

Background. The relationship between tumor suppressor gene miR-302a-3p and radiotherapy for hepatocellular carcinoma (HCC) remains unclear. This study intended to illustrate the molecular mechanism how miR-302a-3p regulated radiotherapy sensitivity of HCC. Methods. miR-302a-3p expression in HCC tissues and cells was examined by qRT-PCR. The effect of miR-302a-3p on HCC radiotherapy sensitivity were detected by CCK-8, colony formation, and flow cytometry assays. The expression levels of cell cycle-related proteins were detected by Western blot. The influence of miR-302a-3p on radiotherapy sensitivity of HCC was further investigated via cell cycle inhibitor (Caudatin) treatment. The target gene (MCL1) of miR-302a-3p was obtained by bioinformatics analysis, and their binding relationship was confirmed by RNA-binding protein immunoprecipitation assay. The mechanisms of miR-302a-3p regulating cell cycle and affecting radiotherapy sensitivity of HCC cells through MCL1 were further explored through the rescue experiments. Results. miR-302a-3p expression was remarkably reduced in radiotherapy-resistant tissues and cells of HCC. miR-302a-3p overexpression restored sensitivity of radiotherapy-resistant HCC cells to radiotherapy. Treatment with cell cycle inhibitor Caudatin could reverse suppressive effect of miR-302a-3p downregulation on sensitivity of HCC to radiotherapy. Additionally, miR-302a-3p could restrain MCL1 expression. In vitro cell assays further revealed that miR-302a-3p/MCL1 axis could enhance radiotherapy sensitivity of HCC cells by inducing G0/G1 arrest. Conclusions. miR-302a-3p facilitated radiotherapy sensitivity of HCC cells by regulating cell cycle via MCL1, which provided a new underlying target for radiotherapy resistance of HCC patients.

CD8+ cell somatic mutations in multiple sclerosis patients and controls-Enrichment of mutations in STAT3 and other genes implicated in hematological malignancies

Somatic mutations have a central role in cancer but their role in other diseases such as common autoimmune disorders is not clear. Previously we and others have demonstrated that especially CD8+ T cells in blood can harbor persistent somatic mutations in some patients with multiple sclerosis (MS) and rheumatoid arthritis. Here we concentrated on CD8+ cells in more detail and tested (i) how commonly somatic mutations are detectable, (ii) does the overall mutation load differ between MS patients and controls, and (iii) do the somatic mutations accumulate non-randomly in certain genes? We separated peripheral blood CD8+ cells from newly diagnosed relapsing MS patients (n = 21) as well as matched controls (n = 21) and performed next-generation sequencing of the CD8+ cells' DNA, limiting our search to a custom panel of 2524 immunity and cancer related genes, which enabled us to obtain a median sequencing depth of over 2000x. We discovered nonsynonymous somatic mutations in all MS patients' and controls' CD8+ cell DNA samples, with no significant difference in number between the groups (p = 0.60), at a median allelic fraction of 0.5% (range 0.2-8.6%). The mutations showed statistically significant clustering especially to the STAT3 gene, and also enrichment to the SMARCA2, DNMT3A, SOCS1 and PPP3CA genes. Known activating STAT3 mutations were found both in MS patients and controls and overall 1/5 of the mutations were previously described cancer mutations. The detected clustering suggests a selection advantage of the mutated CD8+ clones and calls for further research on possible phenotypic effects.

MicroRNAs as potential therapeutic targets for pancreatic cancer

ABSTRACT

Pancreatic cancer is one of the most aggressive malignancies. The poor prognosis of pancreatic cancer patients is mainly attributed to low diagnostic rate at the early stage, highly aggressive nature coupled with the inadequate efficacy of current chemotherapeutic regimens. Novel therapeutic strategies are urgently needed for pancreatic cancer. MicroRNAs (miRNAs) play an important regulatory role in key processes of cancer development. The aberrant expression of miRNAs is often involved in the initiation, progression, and metastasis of pancreatic cancer. The discovery of tumor suppressor miRNAs provides prospects for the development of a novel treatment strategy for pancreatic cancer. We reviewed recent progress on the understanding of the role of miRNAs in pancreatic cancer, highlighted the efficient application of miRNAs-based therapies for pancreatic cancer in animal models and clinical trials, and proposed future prospects. This review focuses on the promise of integrating miRNAs into the treatment of pancreatic cancer and provides guidance for the development of precision medicine for pancreatic cancer.

Histone deacetylase 3 (HDAC3) as an important epigenetic regulator of kidney diseases

Development and progression of many kidney diseases are substantially influenced by aberrant protein acetylation modifications of gene expression crucial for kidney functions. Histone deacetylase (HDAC) expression alterations are detected from renal samples of patients and animal models of various kidney diseases, and the administrations of HDAC inhibitors display impressive renal protective effects in vitro and in vivo. However, when the expression alterations of multiple HDACs occur, not all the HDACs causally affect the disease onset or progression. Identification of a single HDAC as a disease-causing factor will allow subtype-targeted intervention with less side effect. HDAC3 is a unique HDAC with distinct structural and subcellular distribution features and co-repressor dependency. HDAC3 is required for kidney development and its aberrations actively participate in many pathological processes, such as cancer, cardiovascular diseases, diabetes, and neurodegenerative disorders, and contribute significantly to the pathogenesis of kidney diseases. This review will discuss the recent studies that investigate the critical roles of HDAC3 aberrations in kidney development, renal aging, renal cell carcinoma, renal fibrosis, chronic kidney disease, polycystic kidney disease, glomerular podocyte injury, and diabetic nephropathy. These studies reveal the distinct characters of HDAC3 aberrations that act on different molecules/signaling pathways under various renal pathological conditions, which might shed lights into the epigenetic mechanisms of renal diseases and the potentially therapeutic strategies.

LncRNA DHRS4-AS1 ameliorates hepatocellular carcinoma by suppressing proliferation and promoting apoptosis via miR-522-3p/SOCS5 axis

Recent years have seen much effect in revealing the pathological association between lncRNA and HCC. Herein, we identified lncRNA DHRS4-AS1 as a potential tumor suppressor in HCC. Firstly, it was discovered that DHRS4-AS1 was significantly down-regulated in HCC tissues compared to normal tissues based on the database TCGA. It was also detected in a lower-than-usual expression quantity in HCC tissues we collected and HCC cell lines. Kaplan-Meier survival analysis revealed that high expression of DHRS4-AS1 contributed to higher overall survival rate of HCC patients.DHRS4-AS1 expression was significantly correlated to tumor size (P = 0.02) and TNM stage (P = 0.045). CCK-8, BrdU and colony-forming assays collectively demonstrated that overexpression of DHRS4-AS1 significantly restrained HCC cell proliferation. In vivo xenograft animal experiment showed that DHRS4-AS1 could efficiently preclude the tumor growth of HCC. Further investigation performed using flow cytometry and western blot showed that DHRS4-AS1 exerted its effects by accelerating cell apoptosis and capturing cell cycle in G0/G1 phase. Our study subsequently lucubrated that miR-522-3p was a negative target of DHRS4-AS1. Increased expression level of miR-522-3p was examined in HCC tissues and cell lines. Similarly, miR-522-3p mimics could reverse the inhibitory effect on HCC brought by DHRS4-AS1. SOCS5 was then discovered as a down-stream target of miR-522-3p, which suggested that SOCS5 participated in DHRS4-AS1/miR-522-3p axis to collectively mediate the development of HCC. Our study provides lncRNA DHRS4-AS1/miR-522-3p/SOCS5 axis as a novel target for HCC therapeutic strategy with potentiality.

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.

Tumor-derived exosomal miR-19b-3p facilitates M2 macrophage polarization and exosomal LINC00273 secretion to promote lung adenocarcinoma metastasis via Hippo pathway

Numerous reports have elucidated the important participation of exosomes in the communication between tumor cells and other cancer-related cells including tumor-associated macrophages (TAMs) in microenvironment. However, the interchange of exosomes between tumor cells and TAMs in the progression of lung adenocarcinoma (LUAD) remains largely enigmatic. Herein, we discovered that LUAD cells induced the M2 polarization of TAMs and the M2-polarized macrophages facilitated LUAD cell invasion and migration and tumor metastasis in vivo. In detail, LUAD cells secreted exosomes to transport miR-19b-3p into TAMs so that miR-19b-3p targeted PTPRD and inhibited the PTPRD-mediated dephosphorylation of STAT3 in TAMs, leading to STAT3 activation and M2 polarization. Also, the activated STAT3 transcriptionally induced LINC00273 in M2 macrophages and exosomal LINC00273 was transferred into LUAD cells. In LUAD cells, LINC00273 recruited NEDD4 to facilitate LATS2 ubiquitination and degradation, so that the Hippo pathway was inactivated and YAP induced the transcription of RBMX. RBMX bound to miR-19b-3p to facilitate the packaging of miR-19b-3p into LUAD cell-derived exosomes. Collectively, our results revealed the mechanism underlying the interactive communication between LUAD cells and TAMs through elucidating the exchange of exosomal miR-19b-3p and LINC00273 and proved the prometastatic effect of the interchange between two cells. These discoveries opened a new vision for developing LUAD treatment.

MicroRNA-302a-3p induces ferroptosis of non-small cell lung cancer cells via targeting ferroportin

Ferroptosis is a newly described regulated form of cell death that contributes to the progression of non-small cell lung cancers (NSCLCs). MicroRNA-302a-3p (miR-302a-3p) plays critical roles in the tumorigenicity of different cancers; however, its function and underlying mechanism in ferroptosis and NSCLCs remain unclear. Human NSCLCs cells were incubated with miR-302a-3pmimic or inhibitor in the presence or absence of erastin or RSL3. Cell viability, colony numbers, lactate dehydrogenase (LDH) releases, lipid peroxidation and intracellular iron level were measured. Besides, the synergistic effects of cisplatin and paclitaxel with miR-302a-3p were determined. miR-302a-3p level was reduced in human NSCLCs cells and tissues. ThemiR-302a-3p mimic induced lipid peroxidation, iron overload and ferroptosis, thereby inhibiting cell growth and colony formation of NSCLCs cells. Conversely, the miR-302a-3p inhibitor block ederastin- or RSL3-related ferroptosis and tumor suppression. Additionally, we found that miR-302a-3p directly bound to the 3'-untranslational region of ferroportin to decrease its protein expression, and that ferroportin overexpression significantly prevented miR-302a-3p mimic-induced ferroptosis and tumor inhibition. Moreover, the miR-302a-3p mimic sensitized NSCLCs cells to cisplatin and paclitaxel chemotherapy. miR-302a-3p functions as a tumor inhibitor, at least partly, via targeting ferroportin to induce ferroptosis of NSCLCs.

miR-302a-3p suppresses melanoma cell progression via targeting METTL3

The miRNA-302 family plays a critical role in carcinogenesis. As an enzyme that regulates the N6-methyladenosine modification, methyltransferase-like 3 (METTL3) plays important roles in the development and progression of various tumours. However, the upstream regulatory mechanisms of METTL3 in melanoma have not yet been fully investigated. Herein, we investigated the functions of miR-302a-3p and its target RNA METTL3 on proliferation, apoptosis, and invasion of melanoma. Quantitative real-time PCR and immunofluorescence staining were used to measure the expression of METTL3 mRNA and protein level after transfection. miR-302a-3p expression was determined by quantitative reverse transcription-PCR. The cell proliferation, cell cycle progression, apoptosis, colony formation, migration, and cell invasion ability were determined using MTT assay, propidium iodide (PI) staining, Annexin V/PI flow cytometry, plate clone assay, and Transwell migration and invasion assays, respectively. Melanoma cell metastasis was also evaluated using an in vivo model. The effect of METTL3 on the phosphorylation of PI3K and AKT was measured with western blot analysis. Our results showed that miR-302a-3p was significantly downregulated in melanoma and exerted a tumour suppressive role against melanoma progression. We identified METTL3 as a direct target of miR-302a-3p in melanoma cells using bioinformatics analysis and luciferase assay. Furthermore, the enforced overexpression of METTL3 promoted the proliferation, cell cycle progression, cell invasion, migration, expression of epithelial-to-mesenchymal transition markers, and the PI3K-AKT signalling pathway as well as suppressed the apoptosis of melanoma cells. Meanwhile, silencing the expression of METTL3 with specific shRNA demonstrated reverse outcomes of the above phenotypes in melanoma cells. By rescue experiments, we found that the restoration of METTL3 expression in miR-302a-3p-overexpressing melanoma cells successfully recovered the miR-302a-3p-mediated melanoma suppression. The in vivo results also showed that miR-302a-3p substantially inhibited melanoma cell growth and metastasis. In summary, this study demonstrated that miR-302a-3p targets METTL3 and plays tumour suppressive roles in the proliferation, apoptosis, invasion, and migration of melanoma cells.

The LINC01119-SOCS5 axis as a critical theranostic in triple-negative breast cancer

The development of triple-negative breast cancer (TNBC) is critically regulated by certain tumor-microenvironment-associated cells called mesenchymal stem/stromal cells (MSCs), which we and others have shown promote TNBC progression by activating pro-malignant signaling in neighboring cancer cells. Characterization of these cascades would better our understanding of TNBC biology and bring about therapeutics that eliminate the morbidity and mortality associated with advanced disease. Here, we focused on the emerging class of RNAs called long non-coding RNAs or lncRNAs and utilized a MSC-supported TNBC progression model to identify specific family members of functional relevance to TNBC pathogenesis. Indeed, although some have been described to play functional roles in TNBC, activities of lncRNAs as mediators of tumor-microenvironment-driven TNBC development remain to be fully explored. We report that MSCs stimulate robust expression of LINC01119 in TNBC cells, which in turn induces suppressor of cytokine signaling 5 (SOCS5), leading to accelerated cancer cell growth and tumorigenesis. We show that LINC01119 and SOCS5 exhibit tight correlation across multiple breast cancer gene sets and that they are highly enriched in TNBC patient cohorts. Importantly, we present evidence that the LINC01119-SOCS5 axis represents a powerful prognostic indicator of adverse outcomes in TNBC patients, and demonstrate that its repression severely impairs cancer cell growth. Altogether, our findings identify LINC01119 as a major driver of TNBC development and delineate critical non-coding RNA theranostics of potential translational utility in the management of advanced TNBC, a class of tumors in most need of effective and targeted therapy.

Leonurine-Repressed miR-18a-5p/SOCS5/JAK2/STAT3 Axis Activity Disrupts CML malignancy

Leonurine, an active natural alkaloid compound isolated from Herba leonuri, has been reported to exhibit promising anticancer activity in solid tumors. The aim of this study was to explore whether leonurine is able to inhibit chronic myeloid leukemia (CML) malignancy. Here, we found that leonurine dose dependently inhibited the proliferation, migration, colony formation and promoted apoptosis of CML cells. Furthermore, leonurine markedly reduced CML xenograft growth in vivo. Mechanically, leonurine upregulated SOCS5 expression, thus leading JAK2/STAT3 signaling suppression. Silencing of SOCS5 by its siRNA abrogated the effect of leonurine on CML cells, demonstrating that SOCS5 mediates the anti-leukemia effect of leonurine. Notably, we observed that miR-18a-5p was remarkably increased in CML cells. Treating CML cells with leonurine significantly decreased miR-18a-5p expression. Moreover, we found miR-18a-5p repressed SOCS5 by directly targeting its 3′-UTR. miR-18a-5p downregulation induced by leonurine reduced the biological activity of CML cells by relieving miR-18a-5p repression of SOCS5 expression. Taken together, leonurine exerts significant anti-leukemia efficacy in CML by regulating miR-18a-5p/SOCS5/JAK2/STAT3 axis.

Inhibition of Long Noncoding RNA SNHG15 Ameliorates Hypoxia/Ischemia-Induced Neuronal Damage by Regulating miR-302a-3p/STAT1/NF-κB Axis

PURPOSE

Ischemic brain injury results in high mortality and serious neurologic morbidity. Here, we explored the role of SNHG15 in modulating neuronal damage and microglial inflammation after ischemia stroke.

MATERIALS AND METHODS

The hypoxia/ischemia models were induced by middle cerebral artery occlusion in mice and oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro. Quantitative real-time PCR (qRT-PCR) and Western blot were conducted to determine the levels of SNHG15, miR-302a-3p, and STAT1/NF-κB. Moreover, gain- or loss-of functional assays of SNHG15 and miR-302a-3p were conducted. MTT assay was used to evaluate the viability of HT22 cells, and the apoptotic level was determined by flow cytometry. Furthermore, enzyme-linked immunosorbent assay was performed to detect oxidative stress and inflammatory mediators in the ischemia cortex and OGD/R-treated BV2 microglia.

RESULTS

The SNHG15 and STAT1/NF-κB pathways were both distinctly up-regulated, while miR-302a-3p was notably down-regulated in the ischemia cortex. Additionally, overexpressing SNHG15 dramatically enhanced OGD/R-mediated neuronal apoptosis as well as the expression of oxidative stress and inflammation factors from microglia. In contrast, knocking down SNHG15 or overexpressing miR-302a-3p relieved OGD/R-mediated neuronal apoptosis and microglial activation. Moreover, the rescue experiment testified that overexpressing miR-302a-3p also attenuated SNHG15 up-regulation-induced effects. In terms of the mechanisms, SNHG15 sponged miR-302a-3p and activated STAT1/NF-κB as a competitive endogenous RNA, while miR-302a-3p targeted STAT1 and negatively regulated the STAT1/NF-κB pathway.

CONCLUSION

SNHG15 was up-regulated in the hypoxia/ischemia mouse or cell model. The inhibition of SNHG15 ameliorates ischemia/hypoxia-induced neuronal damage and microglial inflammation by regulating the miR-302a-3p/STAT1/NF-κB pathway.

Crosstalk between miRNAs and signaling pathways involved in pancreatic cancer and pancreatic ductal adenocarcinoma

Pancreatic cancer (PC) is the seventh leading cause of cancer-related deaths worldwide with 5-year survival rates below 8%. Most patients with PC and pancreatic ductal adenocarcinoma (PDAC) die after relapse and cancer progression as well as resistance to treatment. Pancreatic tumors contain a high desmoplastic stroma that forms a rigid mass and has a potential role in tumor growth and metastasis. PC initiates from intraepithelial neoplasia lesions leading to invasive cancer through various pathways. These lesions harbor particular changes in signaling pathways involved in the tumorigenesis process. These events affect both the epithelial cells, including the tumor and the surrounding stroma, and eventually lead to the formation of complex signaling networks. Genetic studies of PC have revealed common molecular features such as the presence of mutations in KRAS gene in more than 90% of patients, as well as the inactivation or deletion mutations of some tumor suppressor genes including TP53, CDKN2A, and SMAD4. In recent years, studies have also identified different roles of microRNAs in PC pathogenesis as well as their importance in PC diagnosis and treatment, and their involvement in various signaling pathways. In this study, we discussed the most common pathways involved in PC and PDAC as well as their role in tumorigenesis and progression. Furthermore, the miRNAs participating in the regulation of these signaling pathways in PC progression are summarized in this study. Therefore, understanding more about pathways involved in PC can help with the development of new and effective therapies in the future.

Downregulation of lncRNA ZFAS1 inhibits the hallmarks of thyroid carcinoma via the regulation of miR‑302‑3p on cyclin D1

At present, treatment options for thyroid carcinoma remain limited. The present study aimed to investigate the role of ZFAS1 in various major hallmarks of cancer and the underlying mechanisms in thyroid carcinoma cells. The interactions between long non‑coding RNAs (lncRNAs), microRNAs (miRs) and target genes were predicted by bioinformatics and confirmed by performing dual‑luciferase assays. The mRNA and protein expressions were determined by reverse transcription‑quantitative PCR and western blotting. Cell invasion, migration, and viability were evaluated via Transwell, wound‑healing and Cell Counting Kit‑8 assays, respectively. The results demonstrated that lncRNA ZFAS1 expression was upregulated in thyroid carcinoma tissues, TT and SW579 cells, and was associated with the proliferation of these two cell lines. Notably, downregulation ZFAS1 reduced migration and invasion, and reversed the promotive effects of miR‑302a‑3p inhibitor on the proliferation, migration and invasion of TT and SW579 cells. Moreover, cyclin D1 (CCND1) is targeted by miR‑302a‑3p, and was regulated by ZFAS1. In addition, the downregulation of ZFAS1 not only reversed the promotive effects of miR‑302a‑3p inhibitor on CCND1 expression and the epithelial‑mesenchymal transition (EMT) of TT and SW579 cells, but also targeted and increased the expression of miR‑302a‑3p, and further reduced the expression of CCND1, resulting in suppression of the proliferation, migration, invasion and EMT of thyroid carcinoma cells.

SMARCA2 is regulated by NORFA-miR-29c, a novel pathway that controls granulosa cell apoptosis and is related to female fertility

SMARCA2, an evolutionarily conserved catalytic ATPase subunit of SWI/SNF complexes, has been implicated in development and diseases; however, its role in mammalian ovarian function and female fertility is unknown. Here, we identified and characterized the 3'-UTR of the porcine SMARCA2 gene and identified a novel adenylate number variation. Notably, this mutation was significantly associated with sow litter size traits and SMARCA2 levels, due to its influence on the stability of SMARCA2 mRNA in ovarian granulosa cells (GCs). Immunohistochemistry and functional analysis showed that SMARCA2 is involved in the regulation of follicular atresia by inhibiting GC apoptosis. In addition, miR-29c, a pro-apoptotic factor, was identified as a functional miRNA that targets SMARCA2 in GCs and mediates regulation of SMARCA2 expression via the NORFA-SMAD4 axis. Although a potential miR-29c-responsive element was identified within NORFA, negative regulation of miR-29c expression by NORFA was not due to activity as a competing endogenous RNA. In conclusion, our findings demonstrate that SMARCA2 is a candidate gene for sow litter size traits, because it regulates follicular atresia and GC apoptosis. Additionally, we have defined a novel candidate pathway for sow fertility, the NORFA-TGFBR2-SMAD4-miR-29c-SMARCA2 pathway.This article has an associated First Person interview with the first author of the paper.

Long non-coding RNA PSMA3-AS1 enhances cell proliferation, migration and invasion by regulating miR-302a-3p/RAB22A in glioma

Glioma is the most prevalent solid tumor in the central nervous system (CNS). Recently, it has been indicated that long non-coding RNAs (lncRNAs) substantially adjust the development of a variety of human cancers. In the present study, it was found and verified via microarray analysis that lncRNA PSMA3-AS1 exhibited a high expression in glioma tissues and cell lines. Then CCK-8, 5-Ethynyl-2'-deoxyuridine (EdU) staining, plate clone assay, Transwell assay, Western blotting and nude mouse model were adopted to verify PSMA3-AS1's effects on glioma. Knockdown of PSMA3-AS1 inhibited the migration, proliferation and invasion of glioma cells in vivo and in vitro. Besides, PSMA3-AS1 bound to miR-302a-3p directly reduced the expression of miR-302a-3p, thus functioning as an endogenous sponge confirmed by luciferase reporter assay and bioinformatics analysis. PSMA3-AS1 knockdown remarkably enhanced the role of miR-302a-3p overexpression in cell behaviors in glioma. Moreover, these assays also confirmed that RAB22A was a target of miR-302a-3p. In this research, therefore, the PSMA3-AS1/miR-302a-3p/RAB22A pathway regulatory axis may be revealed in the pathogenesis of glioma, and PSMA3-AS1 can be used as an underlying target for the treatment and prognosis of glioma.

MicroRNA-106a-3p Induces Apatinib Resistance and Activates Janus-Activated Kinase 2 (JAK2)/Signal Transducer and Activator of Transcription 3 (STAT3) by Targeting the SOCS System in Gastric Cancer

Background

MicroRNA (miR)-106a was involved in the tumorigenesis and highly expressed in gastric cancer. Required apatinib resistance greatly limits its efficacy in patients. Thus, the aim of the present study was to investigate the potential role of miR-106a-3p in gastric cancer cells with apatinib-resistance.

Material/Methods

The expression of miR-106a-3p was quantified by real-time quantitative polymerase chain reaction (RT-qPCR). Cell Counting Kit-8 (CCK-8) assay was performed to analyze the sensitivity of gastric cancer cells to apatinib. The expression of relevant drug-resistant proteins was detected by western blot. We searched Targetscan6.2 to find out the target gene of miR-106a-3p. Luciferase reporter assay was used to analyze whether miR-106a-3p bound to relevant gene of SOCS family. The SOCS2, SOCS4, and SOCS5 were qualified by western blot, and their mRNA levels were detected by RT-qPCR. Further, JAK2, STAT3, and their phosphorylation levels were detected by western blot.

Results

The results showed that the expression of miR-106a-3p was increased in apatinib-resistant gastric cancer, while miR-106a-3p inhibitor reduced the drug-resistance of SGC-7901-AP cells to apatinib. Dual luciferase reporter gene assay suggested that SOCS2, SOCS4, and SOCS5 were target genes of miR-106a-3p. The relevant SOCS genes silencing reversed the effects of miR-106a-3p inhibitor on decreasing the apatinib resistance of SGC-7901-AP cells, while the phosphorylation level of JAK and STAT reduced by miR-106a-3p inhibitor were increased.

Conclusions

miR-106a-3p induces apatinib resistance and activates JAK2/STAT3 by targeting SOCS system in gastric cancer. miR-106a-3p/SOCS plays a potent role in gastric cancer cell resistance to apatinib.

The Emerging Roles of ATP-Dependent Chromatin Remodeling Complexes in Pancreatic Cancer

Pancreatic cancer is an aggressive cancer with low survival rates. Genetic and epigenetic dysregulation has been associated with the initiation and progression of pancreatic tumors. Multiple studies have pointed to the involvement of aberrant chromatin modifications in driving tumor behavior. ATP-dependent chromatin remodeling complexes regulate chromatin structure and have critical roles in stem cell maintenance, development, and cancer. Frequent mutations and chromosomal aberrations in the genes associated with subunits of the ATP-dependent chromatin remodeling complexes have been detected in different cancer types. In this review, we summarize the current literature on the genomic alterations and mechanistic studies of the ATP-dependent chromatin remodeling complexes in pancreatic cancer. Our review is focused on the four main subfamilies: SWItch/sucrose non-fermentable (SWI/SNF), imitation SWI (ISWI), chromodomain-helicase DNA-binding protein (CHD), and INOsitol-requiring mutant 80 (INO80). Finally, we discuss potential novel treatment options that use small molecules to target these complexes.

BRM: the core ATPase subunit of SWI/SNF chromatin-remodelling complex-a tumour suppressor or tumour-promoting factor?

BRM (BRAHMA) is a core, SWI2/SNF2-type ATPase subunit of SWI/SNF chromatin-remodelling complex (CRC) involved in various important regulatory processes including development. Mutations in SMARCA2, a BRM-encoding gene as well as overexpression or epigenetic silencing were found in various human diseases including cancer. Missense mutations in SMARCA2 gene were recently connected with occurrence of Nicolaides-Baraitser genetics syndrome. By contrast, SMARCA2 duplication rather than mutations is characteristic for Coffin-Siris syndrome. It is believed that BRM usually acts as a tumour suppressor or a tumour susceptibility gene. However, other studies provided evidence that BRM function may differ depending on the cancer type and the disease stage, where BRM may play a role in the disease progression. The existence of alternative splicing forms of SMARCA2 gene, leading to appearance of truncated functional, loss of function or gain-of-function forms of BRM protein suggest a far more complicated mode of BRM-containing SWI/SNF CRCs actions. Therefore, the summary of recent knowledge regarding BRM alteration in various types of cancer and highlighting of differences and commonalities between BRM and BRG1, another SWI2/SNF2 type ATPase, will lead to better understanding of SWI/SNF CRCs function in cancer development/progression. BRM has been recently proposed as an attractive target for various anticancer therapies including the use of small molecule inhibitors, synthetic lethality induction or proteolysis-targeting chimera (PROTAC). However, such attempts have some limitations and may lead to severe side effects given the homology of BRM ATPase domain to other ATPases, as well as due to the tissue-specific appearance of BRM- and BRG1-containing SWI/SNF CRC classes. Thus, a better insight into BRM-containing SWI/SNF CRCs function in human tissues and cancers is clearly required to provide a solid basis for establishment of new safe anticancer therapies.

miR-302a Inhibits Metastasis and Cetuximab Resistance in Colorectal Cancer by Targeting NFIB and CD44

Introduction: Metastasis and drug resistance contribute substantially to the poor prognosis of colorectal cancer (CRC) patients. However, the epigenetic regulatory mechanisms by which CRC develops metastatic and drug-resistant characteristics remain unclear. This study aimed to investigate the role of miR-302a in the metastasis and molecular-targeted drug resistance of CRC and elucidate the underlying molecular mechanisms.

Methods: miR-302a expression in CRC cell lines and patient tissue microarrays was analyzed by qPCR and fluorescence in situ hybridization. The roles of miR-302a in metastasis and cetuximab (CTX) resistance were evaluated both in vitro and in vivo. Bioinformatic prediction algorithms and luciferase reporter assays were performed to identify the miR-302a binding regions in the NFIB and CD44 3'-UTRs. A chromatin immunoprecipitation assay was performed to examine NFIB occupancy in the ITGA6 promoter region. Immunoblotting was performed to identify the EGFR-mediated pathways altered by miR-302a.

Results: miR-302a expression was frequently reduced in CRC cells and tissues, especially in CTX-resistant cells and patient-derived xenografts. The decreased miR-302a levels correlated with poor overall CRC patient survival. miR-302a overexpression inhibited metastasis and restored CTX responsiveness in CRC cells, whereas miR-302a silencing exerted the opposite effects. NFIB and CD44 were identified as novel targets of miR-302a. miR-302a inhibited the metastasis-promoting effect of NFIB that physiologically activates ITGA6 transcription. miR-302a restored CTX responsiveness by suppressing CD44-induced cancer stem cell-like properties and EGFR-mediated MAPK and AKT signaling. These results are consistent with clinical observations indicating that miR-302a expression is inversely correlated with the expression of its targets in CRC specimens.

Conclusions: Our findings show that miR-302a acts as a multifaceted regulator of CRC metastasis and CTX resistance by targeting NFIB and CD44, respectively. Our study implicates miR-302a as a candidate prognostic predictor and a therapeutic agent in CRC.

MiR-151a-3p Promotes Postmenopausal Osteoporosis by Targeting SOCS5 and Activating JAK2/STAT3 Signaling

Postmenopausal osteoporosis, the most common type of primary osteoporosis, poses a significant threat to women's health worldwide. However, detailed molecular mechanism and therapeutic strategy for postmenopausal osteoporosis remain insufficient. Increasing evidence suggests that microRNAs contributed to the pathogenesis of osteoporosis and could be considered as potential therapeutic targets. In this study, we found that miR-151a-3p was upregulated in osteoporosis samples. Experiments in MC3T3-E1 cells indicated that miR-151a-3p significantly inhibited cell viability and promoted lactate dehydrogenase release, as well as increased RANKL/OPG ratio and decreased Runx2 and BMP2 expressions. SOCS5 was identified as a direct target gene of miR-151a-3p, which was confirmed by luciferase reporter assay. Moreover, an inverse correlation between miR-151a-3p and SOCS5 was observed in osteoporosis femurs. In addition, JAK2/STAT3 pathway was found to be involved in the progress of osteoporosis mediated by miR-151a-3p-SOCS5 axis. In vivo, ovariectomized (OVX) rat model was established to simulate postmenopausal osteoporosis. The results revealed that miR-151a-3p significantly decreased the bone mineral density and biomechanical parameters of femurs in OVX rats by targeting SOCS5, and that JAK2/STAT3 pathway is a downstream target of miR-151a-3p-SOCS5 axis in OVX rats. In conclusion, our findings suggested that miR-151a-3p contributed to the pathogenesis of postmenopausal osteoporosis, and promoted its progress by targeting SOCS5 and activating JAK2/STAT3 signaling. Thus, anti-miR-151a-3p could be a potential therapeutic strategy for postmenopausal osteoporosis.