Dual-luciferase Reporter Assay Research Articles

Human umbilical cord mesenchymal stem cells small extracellular vesicles-derived miR-370-3p inhibits cervical precancerous lesions by targeting DHCR24

Abstract Background Cervical cancer is often caused by persistent high-risk human papillomavirus (HPV) infection, causing precancerous lesions. Human umbilical cord mesenchymal stem cells-derived small extracellular vesicles (hucMSC-sEV) exhibit diverse effects on tumors. This study investigates hucMSC-sEV, the impact and mechanisms on HPV-positive cervical precancerous lesion cells to provide new treatment insights. Materials and Methods We previously obtained hucMSC and hucMSC-sEV. In vitro experiments evaluated hucMSC-sEV effects on the proliferation and migration of S12 cells (derived from cervical precancerous lesions). Bioinformatics identified key microRNA components, and their impact on S12 cell proliferation and migration was investigated. The target gene of the microRNA component was predicted and confirmed via bioinformatics and dual-luciferase reporter assays. Lentiviral systems overexpressed target gene in S12 cells to examine the effects on microRNA impacts. SH-42 inhibitor was used to investigate target gene treatment potential. Immunohistochemistry assessed target gene expression in cervical precancerous lesions tissue. Results hucMSC-sEV significantly inhibited S12 cell proliferation and migration. Bioinformatics identified miR-370-3p as an effective cargo, which also suppressed S12 cell proliferation and migration. miR-370-3p was confirmed targeting DHCR24 (24-Dehydrocholesterol Reductase). DHCR24 overexpression reversed miR-370-3p’s inhibitory effects, while SH-42 counteracted DHCR24 overexpression’s promoting effects. Clinical specimen analysis supported these findings, demonstrating a positive correlation between DHCR24 protein expression and cervical precancerous lesions’ progression. Conclusions hucMSC-sEV inhibits S12 cell proliferation and migration, mediated by miR-370-3p targeting DHCR24 to regulate cellular cholesterol content. DHCR24 inhibition reduces the cholesterol level and cell functions, suggesting its potential as a therapeutic target in cervical precancerous lesions.

NOTCH3 promotes malignant progression of bladder cancer by directly regulating SPP1 and activating PI3K/AKT pathway

AbstractThe biological role and precise molecular mechanisms of Notch receptor 3 (NOTCH3) in the malignant progression of bladder cancer (BLCA) remain unclear. In this study, we found that NOTCH3 was significantly upregulated and associated with poor prognosis in BLCA patients. Functional experiments demonstrated that NOTCH3 knockdown inhibited BLCA cell proliferation, migration, invasion and significantly suppressed tumor growth and metastasis in vivo as well. Mechanically, chromatin immunoprecipitation and dual-luciferase reporter assays confirmed that NOTCH3 could promote the transcription of secreted phosphoprotein 1 (SPP1), a potential downstream target gene of NOTCH3, by binding to the CSL elements in the SPP1 promoter. Moreover, we also found that targeting NOTCH3 inhibited BLCA growth and metastasis by suppressing the SPP1-PI3K/AKT axis. Our study highlights the critical role of NOTCH3-SPP1-PI3K/AKT axis in the malignant progression of BLCA, suggesting that NOTCH3 may be a potential therapeutic target for BLCA.

ADAMTS16 drives epithelial-mesenchymal transition and metastasis through a feedback loop upon TGF-β1 activation in lung adenocarcinoma

AbstractLung adenocarcinoma (LUAD) is the major subtype of lung cancer. The poor prognosis of LUAD patients is attributed primarily to metastasis. ADAMTS16 is a crucial member of the ADAMTS family and is involved in tumor progression. However, its role and regulatory mechanism in LUAD remain unexplored. In this study, ADAMTS16 was identified as a crucial oncogene and survival predictor in LUAD via analyses of public datasets. Clinical specimens and tissue microarrays confirmed the differential expression and prognostic value of ADAMTS16 in LUAD patients. Transcriptome data and in vitro experiments demonstrated that ADAMTS16 was positively associated with epithelial-mesenchymal transition (EMT) and the migration abilities of LUAD cells. Knockdown of ADAMTS16 attenuated lung and pleural metastasis in an animal model. Mechanistically, the results of the enzyme-linked immunosorbent assay (ELISA) and western blot (WB) suggested that ADAMTS16 activated the TGF-β signaling pathway by facilitating the conversion of LAP-TGF-β1 to active TGF-β1. Co-Immunoprecipitation (co-IP) indicated an interaction between ADAMTS16 and LAP-TGF-β1. Inhibition of ADAMTS16 impaired EMT and aggressiveness of LUAD cells, while treatment with recombinant TGF-β1 reversed this inhibition. Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays indicated that SOX4 acted as a transcriptional activator of ADAMTS16 and that TGF-β1 regulated the expression of ADAMTS16 by increasing the binding of SOX4 to the promoter of ADAMTS16. Suppressing the TGF-β signaling pathway inhibited ADAMTS16 expression, EMT, and lung metastasis, whereas overexpressing SOX4 reversed this inhibition. Therefore, ADAMTS16 forms a positive feedback loop with the TGF-β1/SOX4 axis to regulate EMT and metastasis, and disruption of this feedback loop inhibits tumor progression. These findings underscore the potential of ADAMTS16 as a prognostic biomarker and therapeutic target in LUAD and offer novel insight into the mechanism of EMT and metastasis.

Role of the CTCF/p300 axis in osteochondrogenic-like differentiation of polyploid giant cancer cells with daughter cells.

Polyploid giant cancer cells (PGCCs) have properties of cancer stem cells (CSCs). PGCCs with daughter cells (PDCs) undergo epithelial-mesenchymal transition and show enhanced cellular plasticity. This study aimed to elucidate the mechanisms underlying the osteo/chondrogenic-like differentiation of PDCs, which may be exploited therapeutically by transdifferentiation into post-mitotic and functional cells. Cobalt chloride was used to induce PGCC formation in MDA-MB-231 and HEY cells, and PDCs were cultured in osteo/chondrogenic differentiation media. Alcian blue staining was used to confirm osteo/chondrogenic differentiation, and the cell cycle was detected using flow cytometry. The expression of osteo/chondrogenic differentiation-related proteins was compared, and a co-immunoprecipitation assay was used to demonstrate the interactions between proteins. Bioinformatic analysis was used to explore the regulatory mechanism of osteo/chondrogenic differentiation, and a dual-luciferase reporter assay was performed to validate the interaction between transcriptional factors and target genes. Animal xenograft models were used to confirm the osteo/chondrogenic differentiation of PDCs. When cultured in osteo/chondrogenic medium, the stemness of PDCs decreased, and the expression of osteo/chondrogenic-related markers increased. This osteo/chondrogenic-like process was regulated by the transforming growth factor-β pathway in a time-dependent manner. A concurrent increase in the expression of histone acetyltransferase p300 and the transcription factor CCCTC-binding factor (CTCF) was observed. Co-immunoprecipitation assays revealed that p300 acetylated the osteo/chondrogenic marker RUNT-related transcription factor 2 (RUNX2). Analysis of chromatin immunoprecipitation sequencing datasets revealed that both CTCF and histone H3 lysine 27 acetylation (H3K27ac) were enriched in the promoter region of E1A-associated protein p300 (P300). The four predicted binding sites for CTCF and P300 were validated using dual-luciferase reporter assays. We examined the interaction between CTCF and H3K27ac and found that these two proteins had a combined effect on the transactivation of P300. CTCF, in synergy with H3K27ac, amplified the expression of P300, facilitating acetyl group transfer to RUNX2. This acetylation stabilized RUNX2 and promoted osteo/chondrogenic differentiation, thereby reducing the incidence of PDC malignancies.

MicroRNA-429 overexpression overcomes imatinib resistance of glioma cells by negatively regulating lysophosphatidic acid receptor 1

ABSTRACT Background Glioma is one of the most aggressive and lethal malignancies in central nervous system. It has been reported that miR-429 is declined in glioma and functions as a tumor suppressor. Nonetheless, the potential role of miR-429 in drug resistance of glioma is still ambiguous. Methods Stable imatinib-resistant lines U251-AR and T98G-AR were established using glioma cell lines U251 and T98G. Cell apoptosis and cycle were analyzed by flow cytometry, and CCK-8 assay was utilized to measure cell viability. Protein and RNA levels were tested with western blot and RT-qPCR. The predicted binding site was confirmed by dual luciferase reporter assay. Results Imatinib-resistant U251-AR and T98G-AR cells presented lower level of miR-429 and higher level of LPAR1. MiR-429 overexpression obviously promoted imatinib sensitivity in glioma cells, indicated by the reduced IC50 value, facilitated cell apoptosis and cell cycle arrest at G0/G1 phase, and downregulated multidrug resistance-related proteins. LPAR1 was verified as a direct target of miR-429 and its expression was negatively regulated by miR-429. Additionally, overexpression of LPAR1 restrained the biological function of miR-429 on imatinib chemoresistance. Conclusion MiR-429 partly sensitized glioma cells to imatinib via downregulation LPAR1, which might provide an approach to overcome imatinib chemoresistance during glioma treatment.

N6-methyladenosine modification of circular RNA circASH2L suppresses growth and metastasis in hepatocellular carcinoma through regulating hsa-miR-525-3p/MTUS2 axis.

CircRNAs have been demonstrated to play a crucial role in regulating the growth and progression of various cancers, including hepatocellular carcinoma (HCC). Nevertheless, the circRNA's expression pattern and function in HCC need more investigation. Bioinformatics techniques were used to identify differentially expressed circRNAs in HCC. CircASH2L expression in HCC tissues was assessed through qRT-PCR and ISH analysis. To assess circASH2L's impact on HCC progression, a variety of experiments were carried out both in vitro and in vivo, such as CCK8, colony formation, EdU assay, flow cytometry, transwell assay, and xenograft mouse model. Various experimental techniques including qRT-PCR, dual luciferase reporter assay, FISH, RNA pull-down, and RIP experiments were utilized to evaluate the relationship between circASH2L, miR-525-3p, and MTUS2. Additionally, experiments were conducted to explore the impact of m6A modification on circASH2L expression, including RNA stability assay, m6A RNA immunoprecipitation assay (MeRIP), and Co-IP experiments. We found that circASH2L was downregulated in HCC tissues and the downregulation of circASH2L was significantly correlated with malignant characteristics as well as poor overall survival of patients with HCC. CircASH2L was found to inhibit cells growth, migration and invasion as well as tumorigenesis and metastasis in vivo. Mechanistically, we established that circASH2L directly interacted with miR-525-3p to enhance MTUS2 expression, subsequently leading to tumor suppression. Moreover, the influence of circASH2L on tumor suppression was attenuated by increasing miR-525-3p levels, and MTUS2 was recognized as an essential intermediary in circASH2L-induced tumor suppression. Additionally, N6-methyladenosine (m6A) modification was identified in circASH2L. Our data suggested that METTL3 was responsible for mediating m6A methylation of circASH2L, ultimately regulating circASH2L expression through the promotion of its degradation. These findings collectively highlight the role of circASH2L as a tumor suppressor through a unique circASH2L/miR-525-3p/MTUS2 axis, shedding light on the significance of m6A modification in regulating circASH2L function. The work emphasizes circASH2L as a promising therapeutic target for treating HCC, offering new insights into the role of circRNAs in HCC development.

Irisin Improves Preeclampsia by Promoting Embryo Implantation and Vascular Remodeling.

Preeclampsia is a pregnancy-specific disorder with unclear pathogenesis. Irisin, a recently identified exercise-induced factor, significantly influences lipid metabolism and cardiovascular function. Nonetheless, its role in trophoblast development during human placentation and the related intracellular signaling pathways remain poorly understood. We assessed peripheral blood irisin expression in early pregnancy among patients with preeclampsia and its correlation with key clinical indicators. In trophoblast cell lines and mice, we used exogenous irisin and viral knockdown to investigate functional changes. Phosphorylation-specific antibody arrays and dual-luciferase reporter assays were used to explore downstream molecular mechanisms, which were subsequently validated in trophoblast cell lines and relevant gene knockout mice. In early pregnancy, patients with preeclampsia exhibit decreased peripheral blood irisin levels, occurring earlier than traditional predictive markers, such as PLGF (placental growth factor) and sFlt-1 (soluble fms-like tyrosine kinase-1). Furthermore, irisin concentration is positively correlated with proteinuria and abnormal blood pressure during pregnancy. Exogenous irisin significantly enhanced trophoblast cell migration, invasion, and proliferation while inhibiting apoptosis. It also increased STAT (signal transducers and activators of transcription) 4 phosphorylation and its binding to the GLUT (glucose transporter)-3 promoter, resulting in elevated GLUT-3 expression and glucose uptake in trophoblast cells. In vivo, increased peripheral irisin promoted embryo implantation, vascular remodeling, and enhanced glucose uptake, whereas reduced irisin resulted in a preeclampsia-like phenotype characterized by elevated blood pressure, proteinuria, renal-placental dysfunction, adipose accumulation, and restricted fetal growth. Peripheral irisin improves preeclampsia by promoting embryo implantation and vascular remodeling through the activation of the STAT4/GLUT-3 pathway. Reduced peripheral irisin may contribute to preeclampsia-like pathologies. This study supports the advocacy for appropriate exercise during early pregnancy and provides new insights for preeclampsia prevention.

ABC Family Gene Polymorphisms and Cognitive Functions Interact to Influence Antidepressant Efficacy.

The importance of identifying relevant indicators of antidepressant efficacy is highlighted by the low response rates to antidepressant treatment for depression. The ABC gene family, encoding ATP-dependent transport proteins facilitating the transport of psychotropic drugs, has drawn attention. This study delved into the relationship between antidepressant efficacy and seven single nucleotide polymorphisms of ABCB1 and ABCB6 genes. A total of 549 depressed patients participated in the study, and all completed a 6-week course of antidepressant treatment. Cognitive function was assessed at baseline and post-treatment. Patients were categorized based on post-treatment HAMD-17 scores (with HAMD≤7 indicating remission), and comparisons were made between different groups in terms of allelic gene frequencies and genotypes. Logistic regression was used to explore the interaction between cognitive function and genotype on efficacy. Dual-luciferase reporter assays were performed to compare the regulatory effects of rs1109866 allele variants on the ABCB6 promoter. There were no notable differences in allelic gene frequencies and genotypes between the remission and non-remission groups. Nonetheless, a significant interaction was identified between the rs1109866 genotype and language fluency-related indicators concerning efficacy (p=0.029) before correction. The dual-luciferase reporter assays demonstrated markedly higher fluorescence intensity of rs1109866-C compared to that of rs1109866-T (p<0.001). Relying solely on genetic polymorphisms of ABC family genes as predictors of antidepressant treatment response may not be sufficient. However, the interaction between the rs1109866 and cognition plays a pivotal role. The potentially enhanced transcriptional activity of rs1109866-C might offer insight into its impact on antidepressant efficacy.

The LINC01094/miR-545-3p/SLC7A11 Signaling Axis Promotes the Development of Gastric Cancer by Regulating Cell Growth and Ferroptosis.

This study aimed to investigate the role and mechanism of action of LINC01094 in the development of gastric cancer (GC). The expression levels of LINC01094 in GC patients and healthy individuals were analyzed online using the Cancer Genome Atlas database. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analyses were performed to determine the expression of LINC01094/miR-545-3p/SLC7A11 in GC tissues and cells. Functional experiments (MTT assay, colony formation assay, and flow cytometry) were conducted to assess the effect of LINC01094 and miR-545-3p on cell proliferation, viability, apoptosis, cell cycle, and reactive oxygen species. Correlations between LINC01094 and miR-545-3p, as well as SLC7A11, were analyzed and validated using the dual-luciferase reporter assay and RNA immunoprecipitation. The levels of Fe2+, malondialdehyde, and glutathione in the cells were measured biochemically, and the protein expression levels of Bcl-2, cleaved caspase3, Cyclin D1, and p21 were detected by Western blotting. LINC01094 was significantly upregulated in the GC tissues and cells with a targeting relationship with miR-545-3p; the expression levels of LINC01094 and miR-545-3p were negatively correlated. Knockdown of LINC01094 notably inhibited the proliferation and viability of GC cells and promoted cell ferroptosis, which, however, was abrogated by the silencing of miR-545-3p. These findings indicate that miR-545-3p could target and positively correlate with SLC7A11 expression. Additionally, LINC01094 could promote GC cell progression and affect cellular ferroptosis by regulating the miR-545-3p/SLC7A11 signaling axis.

DDX3 participates in miRNA biogenesis and RNA interference through translational control of PACT and interaction with AGO2.

DDX3 is a DEAD-box RNA helicase that plays multiple roles in RNA metabolism, including translation. We previously reported that DDX3 is required for translation of PACT, a binding partner of Dicer, suggesting a role for DDX3 in microRNA (miRNA) biogenesis and RNA interference (RNAi). Emerging evidence suggests that DDX3 plays a vital role in tumorigenesis and cancer progression, however, its underlying mechanism is still not fully understood. Here, we showed that the control of PACT by DDX3 is conserved in human cells and Caenorhabditis elegans. Using a miRNA microarray, we found that DDX3 regulates the expression of a small subset of cancer-related miRNAs. These oncogenic miRNAs were down-regulated by knockdown of DDX3 or PACT and up-regulated by overexpression of DDX3 or PACT in HEK293Tcells. Similar results were obtained in human cancer HCT116 and HeLa cells. Dual luciferase reporter assay showed that DDX3 and PACT are required for short hairpin RNA (shRNA)-induced RNAi. We also performed co-immunoprecipitation to confirm the interaction between DDX3 and AGO2, a significant component of the RNA-induced silencing complex, supporting a role for DDX3 in the RNAi pathway. We further examined the effects of DDX3 and PACT on cell proliferation, and stable overexpression of DDX3 in HEK293 cells results in loss of contact inhibition of cell growth. Hence, we propose that DDX3 may participate in cancer development by regulating the RNAi pathway.

FTO suppresses cardiac fibrosis after myocardial infarction via m6A-mediated epigenetic modification of EPRS.

Cardiac fibrosis is common in myocardial infarction (MI), leading to progressive cardiac dysfunction. Studies suggested that the abnormal N6-methyladenosine (m6A) modification induced by fat mass and obesity protein (FTO) is vital in MI. However, the effects of FTO on post-infarction cardiac fibrosis have not been detected. Western blot and quantitative real-time PCR were performed to detect the expression of FTO in the fibrotic tissue of rats. The functions of FTO on collagen biosynthesis were analyzed in vitro and in vivo. The underlying targets of FTO were selected through RNA-seq with m6A-seq.The following dual luciferase reporter assay and RNA stability assay were conducted to investigate the mechanisms of FTO-mediated m6A regulation. The expression of FTO was decreased in the fibrotic tissue of post-infarction rats. The HIF-1 signal pathway was enriched after MI. HIF-1α could bind to the promoter of FTO and inhibit its expression. Functionally, FTO inhibited collagen synthesis after MI in vitro and in vivo. Mechanistically, EPRS was selected as the underlying target of FTO-induced m6A regulation. IGF2BP3 recognized and bound to the m6A sites of EPRS mRNA, which improved its stability. EPRS was required for cardiac fibrosis induced by FTO silencing. FTO, identified as a cardioprotective factor, suppressed collagen synthesis in post-infarction cardiac fibrosis via m6A modification, which provided a new therapeutic strategy for cardiac fibrosis.

LINC01614 Promotes Oral Squamous Cell Carcinoma by Regulating FOXC1

Background: Long non-coding RNAs (lncRNAs) are pivotal mediators during the development of carcinomas; however, it remains to be investigated whether lncRNAs are implicated in oral squamous cell carcinoma (OSCC). Methods: In this study, quantitative real-time PCR was conducted for detecting the expression of LINC01614 in OSCC cell lines. The biological functions of LINC01614 were assessed by loss- and gain-of-function experiments conducted both in vivo and in vitro. Cellular proliferation, migration, and invasion were investigated herein, and dual luciferase reporter assays were additionally performed to explore the relationships among LINC01614, miR-138-5p, and Forkhead box C1 (FOXC1). Results: The research presented herein revealed that OSCC cells express high levels of LINC01614. Functional experiments employing cellular and animal models demonstrated that LINC01614 knockdown repressed the malignant phenotypes of OSCC cells, including their growth, invasiveness, and migration. Further investigation revealed that LINC01614 absorbs miR-138-5p miRNA by functioning as a competing endogenous RNA to downregulate the abundance of FOXC1. Conclusions: The findings revealed that LINC01614 contributes to the progression of OSCC by targeting the FOXC1 signaling pathway. The study provides insights into a novel mechanistic process to regulate the development of OSCC, and established a possible target for the therapeutic management of OSCC.

Follicular fluid-derived extracellular vesicles miR-34a-5p regulates granulosa cell glycolysis in polycystic ovary syndrome by targeting LDHA.

Polycystic ovary syndrome (PCOS) is highly prevalent in women of reproductive age worldwide, exhibits highly heterogeneous clinical presentation and biochemical parameters, and has no cure. This study aimed to investigate the role of miR-34a-5p in PCOS, its effect on glycolysis in granulosa cells (GCs), and its potential contribution to follicular dysregulation. Herein, Follicular follicular fluid (FF) samples were collected from six patients with PCOS and six healthy controls undergoing in vitro fertilization-embryo transfer. The isolated extracellular vesicles were characterized by transmission electron microscopy, nanoparticle tracking analysis, and western blotting. Additionally, miRNA sequencing was performed to identify differentially expressed microRNAs, and their functions were analyzed through transcriptomics. The In vitro effects of miR-34a-5p on glycolysis, cell proliferation, and apoptosis were assessed in human ovarian granulosa tumour cell line (KGN cells). Targets of miR-34a-5p were identified by dual-luciferase reporter assays, and quantitative real-time polymerase chain reaction and western blotting were performed to determine gene and protein expression. The level of miR-34a-5p in FF-derived extracellular vesicles derived from patients with PCOS was significantly higher than that of the control group. Transcriptomic analysis highlighted miR-34a-5p as a key regulator of glycolysis and apoptosis. Furthermore, in vitro analysis showed that miR-34a-5p targeted lactate dehydrogenase A (LDHA), inhibited glycolysis, reduced energy supply to GCs, and promoted apoptosis of KGN cells. Conversely, miR-34a-5p inhibition restored glycolysis function and cell viability. The findings of this study show that miR-34a-5p mediates GC apoptosis in PCOS by targeting LDHA and inhibiting glycolysis, suggesting its crucial role in PCOS pathophysiology, and offering potential therapeutic targets for improving follicular development and fertility outcomes in patients with PCOS. Further research is needed to explore the clinical implications of miR-34a-5p and its use as a biomarker for early diagnosis and prognosis of PCOS.

Dual Luciferase Reporter Assay in Schizosaccharomyces pombe.

Here, I describe the methods to perform dual luciferase reporter assay in Schizosaccharomyces pombe. The experiment requires the generation of a reporter plasmid construct, with firefly luciferase gene controlled under the genetic element of interest (such as transcriptional promoter or translation initiation signal preceded by a defined promoter) and Renilla luciferase gene expressed under a fixed promoter. S. pombe transformants carrying the plasmids with varied control elements are grown in a selective medium and chilled on ice. Small amounts of cells are pelleted and subjected to the commercially available dual luciferase assay.

Expression of the lncRNA TPT1-AS1 in lung squamous cell carcinoma and its prognostic value.

Lung squamous cell carcinoma is typically associated with a poor prognosis, highlighting the need for a reliable prognostic marker. Given that the long noncoding RNA TPT1-AS1 has demonstrated aberrant expression in numerous cancers, the prognostic significance of TPT1-AS1 in LUSC was examined. The present study included 115 patients diagnosed with LUSC. The expression levels of TPT1-AS1 and miR-4726-5p in tissues and cells were assessed using RT-qPCR, while the correlation between TPT1-AS1 expression and clinicopathological features was analyzed through the chi-square test. Binding sites between TPT1-AS1 and miR-4726-5p were predicted using a database and confirmed via a dual-luciferase reporter assay. The Pearson correlation coefficients were calculated to determine the relationship between TPT1-AS1 and miR-4726-5p in tumor tissues. The impacts of TPT1-AS1 and miR-4726-5p on cells were evaluated through CCK-8 and Transwell assays. TPT1-AS1 expression was found to be reduced, while miR-4726-5p expression was upregulated in LUSC tissues. Patients exhibiting low TPT1-AS1 expression experienced shorter overall survival. Moreover, TPT1-AS1 was identified as an independent prognostic factor. A dual luciferase reporter assay validated that TPT1-AS1-WT targeted and bound to miR-4726-5p. Additionally, an inverse correlation was observed between miR-4726-5p and TPT1-AS1 in tumors. Cell experiments indicated that the overexpression of TPT1-AS1 led to a decrease in miR-4726-5p expression, consequently inhibiting cell proliferation, migration, and invasion. TPT1-AS1 targets miR-4726-5p, and overexpression of TPT1-AS1 has the potential to serve as a prognostic marker for LUSC and can significantly influence LUSC progression.

RBM15-mediated the m6A modification of MAT2A promotes osteosarcoma cell proliferation, metastasis and suppresses ferroptosis.

Methionine adenosyltransferase 2A (MAT2A) has been found to mediate osteosarcoma (OS) progression. Therefore, more roles and mechanisms of MAT2A in the development of OS deserve further exploration. The mRNA and protein levels of MAT2A and RNA binding motif protein 15 (RBM15) were tested by quantitative real-time PCR and western blot (WB). Cell proliferation and metastasis were examined using EdU assay and transwell assay. The protein levels of metastasis-related markers and ferroptosis-related marker were measured by WB. Cell ferroptosis was assessed via testing GSH, ROS, and Fe2+levels. Mice xenograft model was constructed to explore the roles of MAT2A and RBM15 in vivo. RBM15 and MAT2A interaction was assessed by MeRIP assay and dual-luciferase reporter assay. High expression of MAT2A was observed in OS tumor tissues and cells. MAT2A knockdown reduced OS cell proliferation, migration, invasion and enhanced ferroptosis. Silencing of MAT2A inhibited OS tumor growth in vivo. RBM15 was upregulated in OS tumor tissues and cells, which could promote MAT2A expression by N6-methyladenosine (m6A) modification. Downregulation of RBM15 repressed OS cell behaviors and tumorigenesis by decreasing MAT2A expression. In conclusion, MAT2A, regulated by RBM15-mediated m6A modification, accelerated OS malignant progression by increasing cell proliferation, metastasis and decreasing ferroptosis.

Circ_0001741 exerts as a tumor promoter in ovarian cancer through the regulation of miR-491-5p/PRSS8 axis.

Circular RNAs (circRNAs) are important regulators for ovarian cancer (OC). Circ_0001741 has been found to be highly expressed in OC samples and is involved in regulating paclitaxel resistance in OC cells. Therefore, circ_0001741 may play a vital role in OC process, and its potential molecular mechanism is worth further revealing. Circ_0001741, miR-491-5p, and PRSS8 levels in OC tumor tissues and cells were quantified by quantitative real-time PCR or western blot. The proliferation, apoptosis and metastasis of OC cells were detected by cell counting kit 8 assay, Edu assay, flow cytometry, and transwell assay. RNA interaction was verified by dual-luciferase reporter assay and RIP assay. Xenograft assay was used to detect the effect of circ_0001741 knockdown on OC tumor growth in vivo. Circ_0001741 was upregulated in OC tissues and cell lines. Knockdown of circ_0001741 repressed OC cell proliferation, metastasis, and enhanced apoptosis. Mechanistically, miR-491-5p was targeted by circ_0001741, and miR-491-5p inhibitor could attenuate the effect of circ_0001741 silencing on OC cell progression. Meanwhile, PRSS8 was a target of miR-491-5p, and miR-491-5p overexpression inhibited OC cell progression by targeting PRSS8. Circ_0001741 regulated PRSS8 expression by sponging miR-491-5p. Besides, circ_0001741 knockdown also inhibited OC tumor growth in vivo. Our data showed that circ_0001741 could promote the growth and metastasis of OC cells through the miR-491-5p/PRSS8 axis, which provided a potential molecular target for the treatment of OC.

CAF-derived miR-642a-3p supports migration, invasion, and EMT of hepatocellular carcinoma cells by targeting SERPINE1.

Cancer-associated fibroblasts (CAFs) and hepatocellular carcinoma (HCC) cells interact to promote HCC progression, but the underlying mechanisms remain unclear. Serpin family E member 1 (SERPINE1) has conflicting roles in HCC, and microRNAs (miRNAs) are known to regulate tumor progression through intercellular communication. Therefore, we investigated the potential involvement of miRNA/SERPINE1 axis in crosstalk between CAFs and HCC cells. In this study, candidate miRNAs targeting SERPINE1 3' UTR were predicted using multiple miRNA databases. The miRNAs and SERPINE1 mRNA expression in Huh7 cells was assessed after co-culture with CAFs using RT-qPCR. Huh7 cell proliferation and invasion were detected after SERPINE1 siRNA. The functions of the CAF-derived miR-642a-3p/SERPINE1 axis in HCC cells were examined using CCK-8, wound healing, transwell assays, western blot, and dual-luciferase reporter assays. Moreover, a orthotopic xenograft model was used to investigate the contribution of miR-642a-3p knockdown in HCC. SERPINE1 mRNA expression decreased, while miR-642a-3p expression increased in Huh7 cells co-cultured with CAFs. SERPINE1 knockdown enhanced Huh7 cell proliferation and invasion as well as miR-642a-3p expression. miR-642a-3p overexpression promoted migration, invasion, and epithelial-mesenchymal transition (EMT) in Huh7 cells by targeting SERPINE1, while miR-642a-3p knockdown yielded the opposite effect. Rescue experiments confirmed that SERPINE1 knockdown attenuated the inhibitory effects of miR-642a-3p knockdown on migration, invasion, and EMT in Huh7 cells. Importantly, miR-642a-3p knockdown suppressed growth and EMT in orthotopic liver tumors. CAF-derived miR-642a-3p/SERPINE1 axis facilitated migration, invasion, and EMT in the HCC cells, suggesting miR-642a-3p/SERPINE1 axis can be a potential therapeutic target for HCC.

FOSL1 is a key regulator of a super-enhancer driving TCOF1 expression in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with an unmet clinical need, but its epigenetic regulation remains largely undefined. By performing multiomic profiling, we recently revealed distinct super-enhancer (SE) patterns in different subtypes of breast cancer and identified a number of TNBC-specific SEs that drive oncogene expression. One of these SEs, TCOF1 SE, was discovered to play an important oncogenic role in TNBC. However, the molecular mechanisms by which TCOF1 SE promotes the expression of the TCOF1 gene remain to be elucidated. Here, by using combinatorial approaches of DNA pull-down assay, bioinformatics analysis and functional studies, we identified FOSL1 as a key transcription factor that binds to TCOF1 SE and drives its overexpression. shRNA-mediated depletion of FOSL1 results in significant downregulation of TCOF1 mRNA and protein levels. Using a dual-luciferase reporter assay and ChIP-qPCR, we showed that binding of FOSL1 to TCOF1 SE promotes the transcription of TCOF1 in TNBC cells. Importantly, our data demonstrated that overexpression of FOSL1 drives the activation of TCOF1 SE. Lastly, depletion of FOSL1 inhibits tumor spheroid growth and stemness properties of TNBC cells. Taken together, these findings uncover the key epigenetic role of FOSL1 and highlight the potential of targeting the FOSL1-TCOF1 axis for TNBC treatment.

Evaluation of Xihuang Pill in inducing pyroptosis in glioma cells through modulation of miR-21-5p.

This study aims to elucidate the mechanism by which Xihuang Pill induces pyroptosis in glioma cells via the regulation of miR-21-5p. Human glioma cell lines U-87 and LN-229 were used as experimental models to assess the effects of Xihuang Pill on glioma pyroptosis. Cells were incubated with Xihuang Pill extract at concentrations of 7.5, 15, and 30µg/mL for 24h, alongside transfection with miR-21-5p mimic, an overexpression vector for STAT3, or incubation with 50µg/mL of the STAT3 activator Colivelin for 4h. Cell viability was measured using the CCK-8 assay, apoptosis was detected by flow cytometry, and expression levels of p-STAT3/STAT3 and pyroptosis-related proteins were determined by Western Blot. Additionally, cleaved caspase-1 was assessed by immunofluorescence, miR-21-5p expression by qRT-PCR, and STAT3 binding to the miR-21-5p promoter region by ChIP and dual-luciferase reporter assays. Results showed that Xihuang Pill significantly reduced cell viability, increased apoptosis, and upregulated the expression of pyroptosis-related proteins such as NLRP3, IL-1β, cleaved caspase-1, and GSDMD-N, while reducing p-STAT3/STAT3 and miR-21-5p levels (P < 0.05). Xihuang Pill inhibited STAT3 activation, which modulated miR-21-5p expression by binding to its promoter region. Co-transfection with miR-21-5p mimic reversed the effect of Xihuang Pill on glioma pyroptosis (P < 0.05). In conclusion, Xihuang Pill promotes glioma cell pyroptosis through the STAT3/miR-21-5p pathway.