The transcription factor USF1 promotes glioma cell invasion and migration by activating lncRNA HAS2-AS1

E74-like factor 4 promotes the proliferation, invasion, and migration of colorectal cancer cells via long non-coding RNA integrin subunit beta 8 antisense RNA 1-mediated histone H3 lysine 27 trimethylation modification

AIM

Colorectal cancer (CRC) is a common malignancy in the gastrointestinal tract. The main objective of this study is to explore the potential mechanisms of E74-like factor 4 (ELF4) in CRC progression, providing a novel therapeutic target for CRC treatment.

METHODS

CRC cells and normal control cells were cultured. Levels of ELF4/long non-coding RNA integrin subunit beta 8 antisense RNA 1 (LncRNA ITGB8-AS1)/claudin-23 (CLDN23) were detected by real-time quantitative polymerase chain reaction or Western blot assay. ELF4 siRNA, ITGB8-AS1 pcDNA3.1, or CLDN23 siRNA were transfected into cells. Cell proliferation, migration, and invasion were evaluated. The enrichment of ELF4 on the ITGB8-AS1 promoter was detected. Dual-luciferase assay was employed to assess the binding between ELF4 and the ITGB8-AS1 promoter. RNA pull-down and RNA immunoprecipitation assays were conducted to investigate the binding between ITGB8-AS1 and enhancer of zeste homolog 2 (EZH2). The binding of EZH2 and histone H3 lysine 27 trimethylation (H3K27me3) to the CLDN23 promoter was detected.

RESULTS

ELF4 and ITGB8-AS1 were upregulated in CRC cells, while CLDN23 was downregulated. Knockdown of ELF4 inhibited cell proliferation, invasion, and migration. Mechanistically, ELF4 transcriptionally activated ITGB8-AS1 and promoted the binding between ITGB8-AS1 and EZH2. EZH2 catalyzed H3K27me3 modification on the CLDN23 promoter, leading to decreased CLDN23 expression. Overexpression of ITGB8-AS1 or downregulation of CLDN23 could reduce the inhibitory effects of silencing ELF4 on CRC cell proliferation, migration, and invasion.

CONCLUSION

ELF4 accelerates CRC progression through the ITGB8-AS1/CLDN23 axis, providing new therapeutic targets for CRC.

Mef2c- and Nkx2-5-Divergent Transcriptional Regulation of Chick WT1_76127 and Mouse Gm14014 lncRNAs and Their Implication in Epicardial Cell Migration

Cardiac development is a complex developmental process. The early cardiac straight tube is composed of an external myocardial layer and an internal endocardial lining. Soon after rightward looping, the embryonic heart becomes externally covered by a new epithelial lining, the embryonic epicardium. A subset of these embryonic epicardial cells migrate and colonize the embryonic myocardium, contributing to the formation of distinct cell types. In recent years, our understanding of the molecular mechanisms that govern proepicardium and embryonic epicardium formation has greatly increased. We have recently witnessed the discovery of a novel layer of complexity governing gene regulation with the discovery of non-coding RNAs. Our laboratory recently identified three distinct lncRNAs, adjacent to the Wt1, Bmp4 and Fgf8 chicken gene loci, with enhanced expression in the proepicardium that are distinctly regulated by Bmp, Fgf and thymosin β4, providing support for their plausible implication in epicardial formation. The expression of lncRNAs was analyzed in different chicken and mouse tissues as well as their subcellular distribution in chicken proepicardial, epicardial, ventricle explants and in different murine cardiac cell types. lncRNA transcriptional regulation was analyzed by using siRNAs and expression vectors of different transcription factors in chicken and mouse models, whereas antisense oligonucleotides were used to inhibit Gm14014 expression. Furthermore, RT-qPCR, immunocytochemistry, RNA pulldown, Western blot, viability and cell migration assays were conducted to investigate the biological functions of Wt1_76127 and Gm14014. We demonstrated that Wt1_76127 in chicken and its putative conserved homologue Gm14014 in mice are widely distributed in different embryonic and adult tissues and distinctly regulated by cardiac-enriched transcription factors, particularly Mef2c and Nkx2.5. Furthermore, silencing assays demonstrated that mouse Gm14014, but not chicken Wt1_76127, is essential for epicardial, but not endocardial or myocardial, cell migration. Such processes are governed by partnering with Myl9, promoting cytoskeletal remodeling. Our data show that Gm14014 plays a pivotal role in epicardial cell migration essential for heart regeneration under these experimental conditions.

FOXO3 induces TUG1-mediated miR-375/GATA3 signaling axis to promote the survival of melanocytes in vitiligo

Vitiligo is characterized by the depletion of melanocytes due to the activation of CD8+ T cells. Taurine-upregulated gene 1 (TUG1), a long noncoding RNA, is involved in melanogenesis. This study aimed to explore the role and mechanism of TUG1 in vitiligo. RT-qPCR and western blot analyses demonstrated decreased TUG1 levels and increased miR-375 levels in patients with vitiligo. MTT and transwell assays indicated that TUG1 upregulation facilitated melanocyte survival and inhibited CD8+ T cell migration. Dual luciferase reporter and chromatin immunoprecipitation assays verified that Forkhead box O3 (FOXO3) directly interacted with the TUG1 promoter, leading to the positive regulation of TUG1 expression. In addition, FOXO3 promoted melanocyte survival by enhancing the transcription of TUG1. Luciferase reporter assay and RNA immunoprecipitation assay confirmed that TUG1 upregulated GATA binding protein 3 (GATA3) expression by targeting miR-375. TUG1 facilitated melanocyte survival by regulating the miR-375/GATA3 axis. In vitiligo, melanocyte survival is promoted by the induction of the TUG1-mediated miR-375/GATA3 axis by FOXO3, which offers new therapeutic targets for vitiligo treatment.

Metformin enhances the survival ability of ovarian granulosa cells in polycystic ovary syndrome by promoting LINC00548 to suppress androgen receptor/klotho pathway

BACKGROUND

Metformin (Met) has been reported to play the key role in the pathogenesis of polycystic ovary syndrome (PCOS). However, the precise mechanisms underlying the actions of Met in PCOS remain incompletely understood. This study aimed to confirm the mechanism of Met interacting with a long non-coding RNA LINC00548 in PCOS.

METHODS

Ovarian granulosa cells (OGCs) were incubated 500 nM dihydrotestosterone (DHT) to construct PCOS in vitro model and then were treated 20 μM Met. A series of cell experiments including Cell Counting Kit-8, Terminal uridine nucleotide end labeling, and flow cytometry were performed to confirm the changes of OGC survival ability. Quantitative real-time polymerase chain reaction was conducted to determine the levels of LINC00548, whereas Western blotting was applied to determine the levels of androgen receptor (AR) and klotho.

RESULTS

Met improved the cell viability and suppressed cell apoptosis in DHT-treated OGCs. LINC00548 downregulated in DHT-treated OGCs was upregulated by Met, and its overexpression further enhanced the positive effects of Met on the survival ability of DHT-treated OGCs. In addition, Met could induce the upregulation of LINC00548 to suppress the activation of AR/klotho pathway in DHT-treated OGCs.

CONCLUSION

Overall, this study discovers that Met enhances the survival ability of OGCs in PCOS by elevating LINC00548 expression to suppress AR/klotho pathway.

CREB3 facilitates Donafenib resistance in hepatocellular carcinoma cells via the LSD1/CoREST/p65 axis by transcriptionally activating long noncoding RNA ZFAS1

OBJECTIVE

Drug resistance greatly limits the therapeutic effect of a drug. This study aimed to explore the role of long noncoding RNA ZFAS1 in Donafenib resistance of hepatocellular carcinoma (HCC) cells.

METHODS

The expression of CREB3, ZFAS1, and p65 in HCC cell lines was measured by RT-qPCR and western blotting. After transfection with sh-ZFAS1, sh-CREB3, or sh-CREB3 + oe-p65 in Donafenib-resistent (DR) HCC cell lines, the transfection efficiency was evaluated by RT-qPCR and western blotting. The proliferation and IC50 to Donafenib of HCC cell lines was examined by MTT assay. Cell proliferation and apoptosis were examined by colony formation and flow cytometry assays. Then, the correlation amongst CREB3, ZFAS1, LSD1/CoREST, and p65 was analysed by ChIP, dual-luciferase reporter gene, and RIP assays.

RESULTS

ZFAS1, CREB3, and p65 were upregulated in HepG2-DR and Huh7-DR cells. Silencing of ZFAS1 or CREB3 enhanced the sensitivity of HCC cells to Donafenib, inhibited cell proliferation and IC50, and increased cell apoptosis, which were reversed by p65 overexpression. Mechanistically, CREB3 bound to ZFAS1 promoter to augment ZFAS1 transcriptional expression, and ZFAS1 recruited LSD1/CoREST to the p65 promoter region to decrease H3K4 methylation and elevate p65 transcriptional expression.

CONCLUSION

CREB3 overexpression contributed to Donafenib resistance in HCC cells by activating the ZFAS1/p65 axis.

USF1 transcriptionally activates USP14 to drive atherosclerosis by promoting EndMT through NLRC5/Smad2/3 axis

BACKGROUND

Endothelial-to-Mesenchymal Transformation (EndMT) plays key roles in endothelial dysfunction during the pathological progression of atherosclerosis; however, its detailed mechanism remains unclear. Herein, we explored the biological function and mechanisms of upstream stimulating factor 1 (USF1) in EndMT during atherosclerosis.

METHODS

The in vivo and in vitro atherosclerotic models were established in high fat diet-fed ApoE-/- mice and ox-LDL-exposed human umbilical vein endothelial cells (HUVECs). The plaque formation, collagen and lipid deposition, and morphological changes in the aortic tissues were evaluated by hematoxylin and eosin (HE), Masson, Oil red O and Verhoeff-Van Gieson (EVG) staining, respectively. EndMT was determined by expression levels of EndMT-related proteins. Target molecule expression was detected by RT-qPCR and Western blotting. The release of pro-inflammatory cytokines was measured by ELISA. Migration of HUVECs was detected by transwell and scratch assays. Molecular mechanism was investigated by dual-luciferase reporter assay, ChIP, and Co-IP assays.

RESULTS

USF1 was up-regulated in atherosclerosis patients. USF1 knockdown inhibited EndMT by up-regulating CD31 and VE-Cadherin, while down-regulating α-SMA and vimentin, thereby repressing inflammation, and migration in ox-LDL-exposed HUVECs. In addition, USF1 transcriptionally activated ubiquitin-specific protease 14 (USP14), which promoted de-ubiquitination and up-regulation of NLR Family CARD Domain Containing 5 (NLRC5) and subsequent Smad2/3 pathway activation. The inhibitory effect of sh-USF1 or sh-USP14 on EndMT was partly reversed by USP14 or NLRC5 overexpression. Finally, USF1 knockdown delayed atherosclerosis progression via inhibiting EndMT in mice.

CONCLUSION

Our findings indicate the contribution of the USF1/USP14/NLRC5 axis to atherosclerosis development via promoting EndMT, which provide effective therapeutic targets.

Bivalent activity of super-enhancer RNA LINC02454 controls 3D chromatin structure and regulates glioma sensitivity to temozolomide

Glioma cell sensitivity to temozolomide (TMZ) is critical for effective treatment and correlates with patient survival, although mechanisms underlying this activity are unclear. Here, we reveal a new mechanism used by glioma cells to modulate TMZ sensitivity via regulation of SORBS2 and DDR1 genes by super-enhancer RNA LINC02454. We report that LINC02454 activity increases glioma cell TMZ sensitivity by maintaining long-range chromatin interactions between SORBS2 and the LINC02454 enhancer. By contrast, LINC02454 activity also decreased glioma cell TMZ sensitivity by promoting DDR1 expression. Our study suggests a bivalent function for super-enhancer RNA LINC02454 in regulating glioma cell sensitivity to TMZ.

Signatures of tumor-associated macrophages correlate with treatment response in ovarian cancer patients

Ovarian cancer (OC) ranks as the second leading cause of death among gynecological cancers. Numerous studies have indicated a correlation between the tumor microenvironment (TME) and the clinical response to treatment in OC patients. Tumor-associated macrophages (TAMs), a crucial component of the TME, exert influence on invasion, metastasis, and recurrence in OC patients. To delve deeper into the role of TAMs in OC, this study conducted an extensive analysis of single-cell data from OC patients. The aim is to develop a new risk score (RS) to characterize the response to treatment in OC patients to inform clinical treatment. We first identified TAM-associated genes (TAMGs) in OC patients and examined the protein and mRNA expression levels of TAMGs by Western blot and PCR experiments. Additionally, a scoring system for TAMGs was constructed, successfully categorizing patients into high and low RS subgroups. Remarkably, significant disparities were observed in immune cell infiltration and immunotherapy response between the high and low RS subgroups. The findings revealed that patients in the high RS group had a poorer prognosis but displayed greater sensitivity to immunotherapy. Another important finding was that patients in the high RS subgroup had a higher IC50 for chemotherapeutic agents. Furthermore, further experimental investigations led to the discovery that THEMIS2 could serve as a potential target in OC patients and is associated with EMT (epithelial-mesenchymal transition). Overall, the TAMGs-based scoring system holds promise for screening patients who would benefit from therapy and provides valuable information for the clinical treatment of OC.

USF1-mediated ALKBH5 stabilizes FLII mRNA in an m6A-YTHDF2-dependent manner to repress glycolytic activity in prostate adenocarcinoma

Upstream-stimulating factor 1 (USF1) is a ubiquitously expressed transcription factor implicated in multiple cellular processes, including metabolism and proliferation. This study focused on the function of USF1 in glycolysis and the malignant development of prostate adenocarcinoma (PRAD). Bioinformatics predictions suggested that USF1 is poorly expressed in PRAD. The clinical PRAD samples revealed a low level of USF1, which was correlated with an unfavorable prognosis. Artificial upregulation of USF1 significantly repressed glycolytic activity in PRAD cells and reduced cell growth and metastasis in vitro and in vivo. Potential downstream genes of USF1 were probed by integrated bioinformatics analyses. The chromatin immunoprecipitation and luciferase assays indicated that USF1 bound to the α-ketoglutarate-dependent dioxygenase alkB homolog 5 (ALKBH5) promoter for transcription activation. Flightless I (FLII) was identified as the gene showing the highest degree of correlation with ALKBH5. As an m6A demethylase, ALKBH5 enhanced FLII mRNA stability by inducing m6A demethylation in an m6A-YTH N6-methyladenosine RNA-binding protein F2 (YTHDF2)-dependent manner. Either silencing of ALKBH5 or FLII blocked the role of USF1 in PARD cells and restored glycolysis, cell proliferation, and invasion. This study demonstrates that USF1 activates ALKBH5 to stabilize FLII mRNA in an m6A-YTHDF2-dependent manner, thereby repressing glycolysis processes and the progression of PRAD.

SIX1 induced HULC modulates neuropathic pain and Schwann cell oxidative stress after sciatic nerve injury

Neuropathic pain is a severe and debilitating condition caused by damage to the peripheral nerve or central nervous system. Although several mechanisms have been identified, the underlying pathophysiology of neuropathic pain is still not fully understood. Unfortunately, few effective therapies are available for this condition. Therefore, there is an urgent need to investigate the underlying mechanisms of neuropathic pain to develop more effective treatments. Long non-coding RNAs (lncRNAs) have recently gained attention due to their potential to modulate protein expression through various mechanisms. LncRNAs have been implicated in many diseases, including neuropathic pain. This study aimed to identify a novel lncRNA involved in neuropathic pain progression. The lncRNA microarray analysis showed that lncRNA Upregulated in Liver Cancer (HULC) was significantly upregulated in spinal cord tissue of sciatic nerve injury (SNI) rats. Further experiments confirmed that HULC promoted neuropathic pain progression and aggravated H2O2-induced Schwann cell injury. Mechanistically, Sine Oculis Homeobox 1 (SIX1) regulated the transcriptional expression of HULC, and both SIX1 and HULC were involved in neuropathic pain and Schwann cell injury. The results of our research indicate the existence of a previously unknown SIX1/HULC axis that plays a significant role in the development and progression of neuropathic pain, shedding light on the complex mechanisms that underlie this debilitating condition. These findings offer novel insights into the molecular pathways involved in neuropathic pain. This study underscores the potential of targeting lncRNAs as a viable approach to alleviate the suffering of patients with neuropathic pain.

LncRNA FAM13A-AS1, transcriptionally regulated by PHOX2B, modulates hepatocellular carcinoma chemoresistance via stabilizing PPARγ

Hepatocellular carcinoma (HCC) is a major global public health concern, with approximately 79 million new cases and 75 million HCC-related deaths occurring annually worldwide. Among the drugs, cisplatin (DDP) is considered a cornerstone and has been shown to significantly inhibit cancer progression. However, the mechanism underlying DDP-resistance in HCC remains unclear. This study aimed to identify a novel lncRNA. FAM13A Antisense RNA 1 (FAM13A-AS1), that promotes the proliferation of DDP-resistant HCC cells and to elucidate its downstream and upstream mechanisms in the progression of HCC DDP-resistance. Our results suggest that FAM13A-AS1 interacts directly with Peroxisome Proliferator Activated Receptor γ (PPARγ), stabilizing its protein through de-ubiquitination. Moreover, our findings indicate that Paired Like Homeobox 2B (PHOX2B) transcriptionally regulates the expression of FAM13A-AS1 in HCC cells. These results shed new light on the understanding of the progression of HCC DDP-resistance.

The HOXD9-mediated PAXIP1-AS1 regulates gastric cancer progression through PABPC1/PAK1 modulation

Long non-coding RNAs (lncRNAs) have been functionally characterised in various diseases. LncRNA PAX-interacting protein 1-antisense RNA 1 (PAXIP1-AS1) has reportedly been associated with cancer development. However, its role in gastric cancer (GC) remains poorly understood. Here, we showed that PAXIP1-AS1 was transcriptionally repressed by homeobox D9 (HOXD9) and was significantly downregulated in GC tissues and cells. Decreased expression of PAXIP1-AS1 was positively correlated with tumour progression, while PAXIP1-AS1 overexpression inhibited cell growth and metastasis both in vitro and in vivo. PAXIP1-AS1 overexpression significantly attenuated HOXD9-enhanced epithelial-to-mesenchymal transition (EMT), invasion and metastasis in GC cells. Poly(A)-binding protein cytoplasmic 1 (PABPC1), an RNA-binding protein, was found to enhance the stability of PAK1 mRNA, leading to EMT progress and GC metastasis. PAXIP1-AS1 was found to directly bind to and destabilise PABPC1, thereby regulating EMT and metastasis of GC cells. In summary, PAXIP1-AS1 suppressed metastasis, and the HOXD9/PAXIP1-AS1/PABPC1/PAK1 signalling axis may be involved in the progression of GC.

Effect of Exosomal lncRNA MALAT1/miR-370-3p/STAT3 Positive Feedback Loop on PI3K/Akt Pathway Mediating Cisplatin Resistance in Cervical Cancer Cells

Background

Exosomes can encapsulate lncRNA to mediate intercellular communication in cancer progression. Our study devoted to research the effect that long noncoding RNA Metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) influence on cervical cancer (CC).

Methods

MALAT1 and miR-370-3p levels in CC was assessed using qRT-PCR. CCK-8 assay and flow cytometry were devoted to confirm the influence on MALAT1 influencing the proliferation in cisplatin-resistant CC cells. Futher more, MALAT1, combined with miR-370-3p was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation assay.

Results

In CC tissues, MALAT1 turned into substantially expressed, cisplatin-resistant cell lines, as well as exosomes. Cell proliferation was restrained and cisplatin-induced apoptosis was promoted by way of Knockout MALAT1. And promoted the miR-370-3p level, MALAT1 targeted miR-370-3p. Promoting effect of MALAT1 on cisplatin resistance of CC was partially reversed through miR-370-3p. In addition, STAT3 may induce up-regulation of MALAT1 expression in cisplatin-resistant CC cells. It was further confirmed that the effect of MALAT1 on cisplatin-resistant CC cells was achieved by activating PI3K/Akt pathway.

Conclusion

The positive feedback loop of exosomal MALAT1/miR-370-3p/STAT3 mediates the cisplatin resistance of cervical cancer cells affecting PI3K/Akt pathway. Exosomal MALAT1 may become a promising therapeutic target for treating cervical cancer.

Identification of lncRNA-miRNA-mRNA networks in circulating exosomes as potential biomarkers for systemic sclerosis

Objective

This study aimed to analyze potential biomarkers for systemic sclerosis (SSc) by constructing lncRNA-miRNA-mRNA networks in circulating exosomes (cirexos).

Materials and methods

Differentially expressed mRNAs (DEmRNAs) and lncRNAs (DElncRNAs) in SSc cirexos were screened using high-throughput sequencing and detected with real-time quantitative PCR (RT-qPCR). Differentially expressed genes (DEGs) were analyzed using the DisGeNET, GeneCards, GSEA4.2.3, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Receiver operating characteristic (ROC) curves, correlation analyses, and a double-luciferase reporter gene detection assay were used to analyze competing endogenous RNA (ceRNA) networks and clinical data.

Results

In this study, 286 DEmRNAs and 192 DElncRNAs were screened, of which 18 DEGs were the same as the SSc-related genes. The main SSc-related pathways included extracellular matrix (ECM) receptor interaction, local adhesion, platelet activation, and IgA production by the intestinal immune network. A hub gene, COL1A1, was obtained by a protein-protein interaction (PPI) network. Four ceRNA networks were predicted through Cytoscape. The relative expression levels of COL1A1, ENST0000313807, and NON-HSAT194388.1 were significantly higher in SSc, while the relative expression levels of hsa-miR-29a-3p, hsa-miR-29b-3p, and hsa-miR-29c-3p were significantly lower in SSc (P < 0.05). The ROC curve showed that the ENST00000313807-hsa-miR-29a-3p-COL1A1 network as a combined biomarker of SSc is more valuable than independent diagnosis, and that it is correlated with high-resolution CT (HRCT), Scl-70, C-reactive protein (CRP), Ro-52, IL-10, IgM, lymphocyte percentage, neutrophil percentage, albumin divided by globulin, urea, and RDW-SD (P < 0.05). Double-luciferase reporter gene detection showed that ENST00000313807 interacts with hsa-miR-29a-3p, which interacts with COL1A1.

Conclusion

The ENST00000313807-hsa-miR-29a-3p-COL1A1 network in plasma cirexos represents a potential combined biomarker for the clinical diagnosis and treatment of SSc.

USF1-CHCHD4 axis promotes lung adenocarcinoma progression partially via activating the MYC pathway

BACKGROUND

This study aimed to identify genes related to lung adenocarcinoma (LUAD) and investigate the effects and molecular mechanisms of coiled-coil-helix-coiled-coil-helix domain containing 4 (CHCHD4) in the progression of LUAD.

METHODS

The GEPIA database was used to evaluate the differential expression of CHCHD4 and the survival data of LUAD patients compared to controls. TCGA-LUAD database, JASPAR website, and GSEA were used to analyse the relationship between CHCHD4 and the upstream stimulating factor 1 (USF1) or MYC pathways. The proliferation, apoptosis, migration, and invasion of LUAD cells were evaluated using cell counting kit-8, 5-ethynyl-2'-deoxyuridine, colony formation, flow cytometry, wound healing, and transwell assays. qRT-PCR, western blotting, and immunohistochemistry were used to detect the mRNA and protein expression, respectively. Furthermore, xenograft tumours from nude mice were used to verify the effect of CHCHD4 on LUAD in vivo.

RESULTS

CHCHD4 overexpression was found in LUAD tumor tissues and cells, and high CHCHD4 was associated with a poor prognosis. Interestingly, CHCHD4 knockdown suppressed the malignant phenotype of the LUAD cells. Moreover, we found that USF1 upregulated CHCHD4 and promoted LUAD progression. CHCHD4 knockdown also inhibited the progression of LUAD. In addition, CHCHD4 knockdown suppressed xenograft tumour growth.

CONCLUSION

USF1-CHCHD4 axis can promote LUAD progress, which may be through activating MYC pathway.

MITF-Mediated lncRNA CCDC183-As1 Promotes the Tumorigenic Properties and Aerobic Glycolysis of Bladder Cancer via Upregulating TCF7L2

As a primary malignancy tumor of the urology system, bladder cancer (BC) is characterized by its high recurrence and metastasis characteristics. Despite the great improvement in clinical interventions over the past decades, the outcomes of BC patients are still unsatisfactory. Novel molecular mechanisms for developing effective diagnostic and therapeutic strategies are urgently needed; therefore, we screened the lncRNA expression profile in four pairs of BC tissues, showing that CCDC183-AS1 was the most upregulated lncRNA. Subsequently, results of CCK-8, EdU, Transwell, and aerobic glycolysis detection showed that CCDC183-AS1 plays an oncogene role in BC progression. Furthermore, an investigation of the downstream and upstream factors of CCDC183-AS1 identified a novel MITF/CCDC183-AS1/miR-4731-5p/TCF7L2 axis in BC progression, which might furnish novel insights for developing effective diagnostic and therapeutic strategies for BC.

Long non-coding RNA NRSN2-AS1, transcribed by SOX2, promotes progression of esophageal squamous cell carcinoma by regulating the ubiquitin-degradation of PGK1

Aberrant expression of long non-coding RNAs (lncRNAs) plays pivotal roles in tumorigenesis of human malignant cancers, including esophageal squamous cell carcinoma (ESCC). However, the specific role of lncRNA NRSN2-AS1 in ESCC has not been investigated. Our analysis of clinical data revealed that NRSN2-AS1 was upregulated in ESCC tissues and negatively correlated with patient survival. Luciferase reporter assays and chromatin immunoprecipitation assays demonstrated that NRSN2-AS1 is transcribed by SOX2. In vitro functional experiments showed that NRSN2-AS1 can promote ESCC cell proliferation, migration, and invasion. Furthermore, NRSN2-AS1-binding proteins were detected using RNA pull-down assays and mass spectrometry. Mechanistically, NRSN2-AS1 can bind to phosphoglycerate kinase 1 (PGK1) and upregulate its protein levels by inhibiting its ubiquitination. Knockdown of PGK1 in part abolished the NRSN2-AS1 overexpression-induced effects on ESCC cell proliferation, migration, invasion, and epithelial‑mesenchymal transition (EMT). Thus, NRSN2-AS1 may be a diagnostic biomarker or treatment target for ESCC.

Identifying a novel KLF2/lncRNA SNHG12/miR-494-3p/RAD23B axis in Spare Nerve Injury-induced neuropathic pain

Spinal cord injury (SCI) is a devastating condition for patients, affecting nearly 2.5 million people globally. Multiple side effects of SCI have resulted in a terrible life experience for SCI patients, of which neuropathic pain has attracted the most scientific interest. Even though many efforts have been made to attenuate or eliminate neuropathic pain induced by SCI, the outcomes for patients are still poor. Therefore, identifying novel diagnosis or therapeutic targets of SCI-induced neuropathic pain is urgently needed. Recently, multiple functions of long non-coding RNA (lncRNA) have been elucidated, including those in SCI-induced neuropathic pain. In this study, lncRNA small nucleolar RNA host gene 12 (SNHG12) was found to be upregulated in the dorsal root ganglion (DRGs) of rats with spare nerve injury (SNI). By constructing SCI rat models, we found that lncRNA SNHG12 expression was increased in the DRGs, and mainly distributed in the cytoplasm of PC12 cells. Paw withdrawal threshold (PWT), paw withdrawal latency (PWL), and enzyme linked immunosorbent assay (ELISA) results indicated that lncRNA SNHG12 knockdown attenuated SNI-induced neuropathic pain, and decreased the expression levels of interleukin (IL)−1β, IL-6, and tumour necrosis factor α (TNF-α) in the DRGs. Bioinformatics analysis, RNA pull-down, chromatin immunoprecipitation (ChIP), and luciferase reporter gene assays showed that lncRNA SNHG12 regulates the RAD23 homologue B, nucleotide excision repair protein (RAD23B) expression, through targeting micro RNA (miR)−494-3p. Furthermore, the study indicated that Kruppel-Like Factor 2 (KLF2) could regulate lncRNA SNHG12 expression in PC12 cells. This study identified a novel KLF2/lncRNA SNHG12/miR-494-3p/RAD23B axis in SNI-induced neuropathic pain, which might provide a new insight for developing novel diagnosis, or therapeutic targets of SCI-induced neuropathic pain in the future.

SEZ6L2, regulated by USF1, accelerates the growth and metastasis of breast cancer

Breast cancer (BC) is the second cause of cancer-related mortality in women. Seizure related 6 homolog like 2 (SEZ6L2), a protein presented on cell surface, is involved in tumor development. It was found to be highly expressed in BC, however, its role in BC remains unclear. Herein, we aimed to explore the role of SEZ6L2 in BC. Firstly, the correlationship between SEZ6L2 expression and the clinic pathological characteristics of patients diagnosed with BC was analyzed. Subsequently, the role of SEZ6L2 was further explored using MTT, transwell invasion, flow cytometry, colony formation and wound healing assays. The result showed that the level of SEZ6L2 was remarkably correlated with the TNM stage, HER-2 status and lymph node metastasis of BC. Knockdown of SEZ6L2 significantly suppressed the proliferation of BC cells and induced cell cycle arrest at G1 phase. In addition, SEZ6L2 knockdown repressed their migration and invasion. On the contrary, SEZ6L2 overexpression performed the opposite effects. Furthermore, SEZ6L2 also accelerated the in vivo tumorigenesis of BC cells. Additionally, according to bioinformatics resources, we identified upstream transcription factor 1 (USF1) as a transcriptional factor which bound to the promoter of SEZ6L2 and positively regulated its transcription. In conclusion, this study demonstrated that SEZ6L2 was transcriptionally regulated by USF1 and was involved in the growth and metastasis of BC cells. Revealing the role of SEZ6L2 in BC provides additional knowledge for the pathogenesis of BC, which may benefit to BC therapy.

The natural antisense transcript HAS2-AS1 regulates breast cancer cells aggressiveness independently from hyaluronan metabolism

Hyaluronan (HA) is a ubiquitous extracellular matrix component playing a crucial role in the regulation of cell behaviors, including cancer. Aggressive breast cancer cells tend to proliferate, migrate and metastatize. Notably, triple-negative breast cancer cells lacking the expression of estrogen receptor (ER) as well as progesterone receptor and HER2 are more aggressive than ER-positive ones. As currently no targeted therapy is available for triple-negative breast cancer, the identification of novel therapeutic targets has a high clinical priority. In ER-negative cells, tumoral behavior can be reduced by inhibiting HA synthesis or silencing the enzymes involved in its metabolism, such as HA synthase 2 (HAS2). HAS2-AS1 is a long non-coding RNA belonging to the natural antisense transcript family which is known to favor HAS2 gene expression and HA synthesis, thus bolstering malignant progression in brain, ovary, and lung tumors. As the role of HAS2-AS1 has not yet been investigated in breast cancer, in this work we report that ER-positive breast cancers had lower HAS2-AS1 expression compared to ER-negative tumors. Moreover, the survival of patients with ER-negative tumors was higher when the expression of HAS2-AS1 was elevated. Experiments with ER-negative cell lines as MDA-MB-231 and Hs 578T revealed that the overexpression of either the full-length HAS2-AS1 or its exon 2 long or short isoforms alone, strongly reduced cell viability, migration, and invasion, whereas HAS2-AS1 silencing increased cell aggressiveness. Unexpectedly, in these ER-negative cell lines, HAS2-AS1 is involved neither in the regulation of HAS2 nor in HA deposition. Finally, transcriptome analysis revealed that HAS2-AS1 modulation affected several pathways, including apoptosis, proliferation, motility, adhesion, epithelial to mesenchymal transition, and signaling, describing this long non-coding RNA as an important regulator of breast cancer cells aggressiveness.

USF1 Transcriptionally Regulates UGT1A3 and Promotes Lung Adenocarcinoma Progression by Regulating Neurotrophin Signaling Pathway

Background: Lung cancer remains the leading cause of oncological death. There is an urgent need to discover new molecular targets and to develop new treatments. Our previous study showed that one of the UDP-glucuronosyltransferases (UGTs) family, UGT1A3, is an important prognostic factor for lung adenocarcinoma (LUAD), inhibiting UGT1A3 could significantly improve the efficacy of anti-tumor drugs. In this study, we aimed to explore the upstream transcriptional factor (USF1) of UGT1A3 and its way of playing a role in LUAD.

Methods: The UGT1A3 promoter region was analyzed and dual-luciferase assay was involved to explore whether USF1 could bind to this region, and the possible regulation effects of USF1 to UGT1A3 was indicated by siRNA and recovery experiment. Then, the Cancer Genome Atlas database was used to analyze USF1 clinical features. The expression level of USF1 was detected by immunohistochemical assay and Western blotting. Cellular viability, proliferation, migration and invasion potential were also investigated. Meanwhile, the effect of USF1 in LUAD progression was detected in a mouse model. The downstream signaling pathway was analyzed by bioinformatic analysis and the expression of all related proteins was detected.

Results: UGT1A3 was transcriptionally regulated by USF1, which was highly expressed in all investigated samples including patients’ tissues, studied cells lines, and mouse models. The knockdown of USF1 inhibited cells viability, proliferation, migration and invasion, and reduced the tumor volume. Moreover, USF1 promoted the progress of LUAD by regulating the neurotrophin signaling pathway.

Conclusion: As an important transcriptional regulator of UGT1A3, USF1 was highly expressed in LUAD and promoted LUAD progression by regulating the neurotrophin signaling pathway. These findings provide a new theoretical data that could serve as a good foundation for the treatment of LUAD.

NFIB-Mediated lncRNA PVT1 Aggravates Laryngeal Squamous Cell Carcinoma Progression via the miR-1301-3p/MBNL1 Axis

Laryngeal squamous cell carcinoma (LSCC) is one of the most common malignant tumors of head and neck cancers. In the past decades, although the therapy strategies of LSCC have made considerable improvement, the terrible outcomes of LSCC still bring an enormous burden to the world health care system. Novel therapeutic targets for LSCC are urgently needed. lncRNAs exert important roles in various biological progressions, including LSCC. Here, we aimed to investigate the function of lncRNA PVT1 in LSCC progression and its underlying molecular mechanisms. By conducting multiple experiments, our results showed that lncRNA PVT1 was upregulated in LSCC cell lines and regulated LSCC cell proliferation, apoptosis, and its cell susceptibility to natural killer (NK) cells. Moreover, it was found that lncRNA PVT1 promotes MBNL1 expression to regulate LSCC cellular progression through sponging miR-1301-3p. Our study might provide novel targets for LSCC basic research or clinical management.

Liver-Metastasis-Related Genes are Potential Biomarkers for Predicting the Clinical Outcomes of Patients with Pancreatic Adenocarcinoma

It is widely acknowledged that metastasis determines the prognosis of pancreatic adenocarcinoma (PAAD), and the liver is the most primary distant metastatic location of PAAD. It is worth exploring the value of liver-metastasis-related genetic prognostic signature (LM-PS) in predicting the clinical outcomes of PAAD patients post R0 resection. We collected 65 tumors and 165 normal pancreatic data from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression project (GTEx), respectively. Differentially expressed genes (DEGs) between primary tumor and normal pancreatic samples were intersected with DEGs between primary tumor samples with liver metastasis and those without new tumor events. The intersected 45 genes were input into univariate Cox regression analysis to identify the prognostic genes. Thirty-three prognostic liver-metastasis-related genes were identified and included in least absolute shrinkage and selection operator (LASSO) analysis to develop a seven-gene LM-PS, which included six risk genes (ANO1, FAM83A, GPR87, ITGB6, KLK10, and SERPINE1) and one protective gene (SMIM32). The PAAD patients were grouped into low- and high-risk groups based on the median value of risk scores. The LM-PS harbored an independent predictive ability to distinguish patients with a high-risk of death and liver metastasis after R0 resection. Moreover, a robust prognostic nomogram based on LM-PS, the number of positive lymph nodes, and histologic grade were established to predict the overall survival of PAAD patients. Besides, a transcription factor‐microRNA coregulatory network was constructed for the seven LM-PS genes, and the immune infiltration and genomic alterations were systematically explored in the TGCA-PAAD cohort.

Non-coding RNA in cancer

Majority of the human genome is transcribed to RNAs that do not encode proteins. These non-coding RNAs (ncRNAs) play crucial roles in regulating the initiation and progression of various cancers. Given the importance of the ncRNAs, the roles of ncRNAs in cancers have been reviewed elsewhere. Thus, in this review, we mainly focus on the recent studies of the function, regulatory mechanism and therapeutic potential of the ncRNAs including microRNA (miRNA), long ncRNA (lncRNA), circular RNA (circRNA) and PIWI interacting RNA (piRNA), in different type of cancers.

The Transcription Factor C/EBPβ Promotes HFL-1 Cell Migration, Proliferation, and Inflammation by Activating lncRNA HAS2-AS1 in Hypoxia

Objective

Recent studies were widely concerned about the role of lncRNAs in hypoxic pulmonary hypertension (HPH). HAS2 was found significantly highly expressed in HPH, but the antisense of HAS2 (HAS2-AS1) has not been explored in HPH, providing a new potential therapeutic target of HPH.

Methods

In this study, human fetal lung fibroblast-1 (HFL-1) cells were cultured under hypoxia conditions to stimulate the pathological process of HPH. Transwell and wound-healing assays were used to detect HFL-1 cell migration, and CCK 8 assay was used to detect cell proliferation. The upstream transcription factor of HAS2-AS1 was predicted by JASPAR website, and the binding site between C/EBPβ and HAS2-AS1 was predicted by JASPAR, too. In order to verify the association between C/EBPβ and the HAS2 promoter region, we used chromatin immunoprecipitation (ChIP) and dual luciferase reporter gene detection, western blot to detect the expression of inflammation-related proteins, and qRT-PCR to detect the expression of HAS2-AS1 and HAS2. Idiopathic pulmonary fibrosis (IPF) with HPH patient microarray data was downloaded from the GEO database and analyzed by R software.

Results

Our study showed that HAS2-AS1 and C/EBPβ were highly expressed in hypoxic HFL-1 cells, and the knockdown of HAS2-AS1 expression could inhibit the proliferation, migration, and inflammatory response of HFL-1 cells. C/EBPβ binds to the promoter region of HAS2-AS1 and has a positive regulation effect on the transcription of HAS2-AS1. Furthermore, C/EBPβ can regulate the proliferation, migration, and inflammatory response of HFL-1 cells through HAS2-AS1.

Conclusion

This study suggested that C/EBPβ could upregulate HAS2-AS1 expression and induce HFL-1 cell proliferation, migration, and inflammation response.

Deletion of Sox9 in the liver leads to hepatic cystogenesis in mice by transcriptionally downregulating Sec63

Hepatic cysts are found in heterogeneous disorders with different pathogeneses, of which simple hepatic cysts and polycystic liver diseases are two major types. The process of hepatic cytogenesis for these two diseases is caused by defects in remodelling of the ductal plate during biliary tract development, which is called ductal plate malformation. SOX9 is a transcription factor participating in the process of bile duct development, and thus, its dysregulation may play important roles in hepatic cystogenesis. SEC63 encodes an endoplasmic reticulum membrane protein that is mutated in human autosomal dominant polycystic liver disease. However, the transcriptional regulation of SEC63 is largely unknown. In the present study, a liver-specific Sox9 knockout (Sox9^LKO ) mouse was generated to investigate the roles and underlying mechanism of SOX9 in hepatic cystogenesis. We found that hepatic cysts began to be observed in Sox9^LKO mice at 6 months of age. The number and size of cysts increased with age in Sox9^LKO mice. In addition, the characteristics of hepatic cytogenesis, including the activation of proliferation, absence of primary cilium, and disorder of polarity in biliary epithelial cells, were detected in the livers of Sox9^LKO mice. RNAi silencing of SOX9 in human intrahepatic biliary epithelial cells (HIBEpic) resulted in increased proliferation and reduced formation of the primary cilium. Moreover, Sec63 was downregulated in primary biliary epithelial cells from Sox9^LKO mice and SEC63 in HIBEpic transfected with siSOX9. Chromatin immunoprecipitation assays and luciferase reporter assays further demonstrated that SOX9 transcriptionally regulated the expression of SEC63 in biliary epithelial cells. Importantly, the overexpression of SEC63 in HIBEpic partially reversed the effects of SOX9 depletion on the formation of primary cilia and cell proliferation. These findings highlight the biological significance of SOX9 in hepatic cytogenesis and elucidate a novel molecular mechanism underlying hepatic cytogenesis. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.