Suppressor Gene Research Articles

Blocking p85β nuclear translocation by importazole enhances Alpelisib efficacy against PIK3CA-helical-domain-mutant tumors.

PIK3CA, which encodes protein p110α, is one of the most frequently mutated oncogenes and a promising drug-target for human cancer. Previously, we demonstrate that p85β is released from PI3K complex which contain PIK3CA helical domain mutations and translocates into nucleus to regulate tri-methylation of H3K27, thereby promoting tumorigenicity. Here, we identify DIRAS2 and SOWAHB as target genes of nuclear p85β in PIK3CA-helical-domain-mutant tumors. DIRAS2 and SOWAHB are tumor suppressive genes, whose expression are repressed by nuclear p85β through histone methyltransferase EZH2. More importantly, combination of PI3K inhibitor and importin-β inhibitor effectively inhibits the growth of PIK3CA-helical-domain-mutant tumors by synchronously blocking both AKT signaling and nuclear p85β/DIRAS2 and SOWAHB axis. In this study, we evaluate the combination effect of Alpelisib and Importazole for PIK3CA helical domain mutant tumors and demonstrate its underlying mechanism.

Digestion and absorption of triacetin, a short-chain triacylglycerol.

Triacylglycerol (TG) is categorized into long-, medium-, and short-chain TG (SCTG). While the digestion of long- and medium-chain TG is well established, the process for SCTG remains unclear. This study investigated SCTG digestion by administering 2 mmol of triacetin to rats and analyzing acetin, acetic acid, and glycerol levels in the portal blood and small intestine. Triacetin was fully degraded in the upper gastrointestinal tract and absorbed as acetic acid and glycerol. Glycerol influx into the liver promoted gluconeogenesis, while acetate activated AMPK, resulting in the suppression of fatty acid synthesis-related genes and the upregulation of fatty acid β-oxidation-related genes. These findings demonstrate that triacetin not only serves as a substrate for energy metabolism but also regulates hepatic gene expression, highlighting its dual role as both a metabolic substrate and signaling molecule. Triacetin thus shows potential as a dietary modulator for improving metabolic health.

Tumor cells upregulate neurotransmitter GABA in the choroid plexus through STAT6-Bestrophin1 signaling, promoting leptomeningeal dissemination.

Leptomeningeal dissemination (LMD) occurs when tumor cells interact with choroid plexus epithelium (CPE) to gain access to cerebrospinal fluid (CSF) in the brain's meninges and ventricular system. This disease is particularly devastating for patients due to our limited understanding and few therapeutic options. The leptomeningeal CSF is a nutritionally deprived microenvironment for tumor cells. Despite this, LMD tumor cells survive by taking up and metabolizing the neurotransmitter GABA from the CSF. However, we currently lack evidence on how CSF-GABA levels are altered and how tumor cells communicate with the choroid plexus epithelium to increase GABA levels in the LMD microenvironment. Herein, we examined the interactions between CPEs and tumor cells that make CSF more hospitable to LMD growth. We utilized primary choroid plexus, breast cancer cell and patient-derived breast and lung to brain metastatic cells along with in-vivo modeling along with STAT6 inhibitor and IL13 gene knockdown. We show breast and lung cancer cells derived-IL13 activates STAT6 signaling in choroid plexus. Subsequently, choroid plexus upregulates GABA-synthesizing enzyme GAD67 and GABA-permeable channel Bestrophin-1, all leading to elevated neurotransmitter GABA levels in the cerebrospinal fluid. Moreover, we show a significant reduction of Bestrophin1 in choroid plexus when tumor-derived IL13 is knocked down or when treated with brain permeable STAT6 specific inhibitor AS1517499, leading to increased survival. Overall, these findings reveal a novel STAT6-Bestrophin1-GABA axis in choroid plexus and its therapeutic targeting can lead to favorable outcomes in leptomeningeal disease.

A Coordination Nanosystem Enables Endogenous Ferric Ion-Initiated Multi-Catalysis for Synergistic Tumor-Specific Ferroptosis and Gene Therapy.

Emerging evidence demonstrates that inducing ferroptosis, a nonapoptotic programmed cell death mode, holds significant potential for tumor treatment. However, current ferroptosis strategies utilizing exogenous Fenton-type heavy metal species or introducing glutathione (GSH)/glutathione peroxidase 4 (GPX4) suppressants are hampered by latent adverse effects toward organisms, while utilizing endogenous iron may cause undesirable tumor angiogenesis through specific signaling pathways. Here, aferric ion (Fe3+)-responsive and DNAzyme-delivered coordination nanosystem (ZDD) is developed to achieve a novel scheme of synergistic tumor-specific ferroptosis and gene therapy, which modulates and harnesses the endogenous iron in tumors for inducing ferroptosis while intercepting tumor angiogenesis to enhance therapeutic efficacy. Profiting from the characteristic coordination structure and components, ZDD can not only specifically capture tumor endogenous Fe3+ into the tumor cells to promote the catalytic generation of hydroxyl radicals (·OH) and superoxide anions (O2·-) under acidic environment and the catalytic GSH oxidation, arousing potent ferroptotic cell death, but also effectively deliver specific DNAzyme and release abundant zinc ion (Zn2+) as a powerful cofactor to activate the biocatalytic cleavage of vascular endothelial growth factor receptor 2 (VEGFR2) gene for angiogenesis suppression. Ultimately, the ZDD-enabled synergistic therapy prominently inhibited tumor growth and prevented metastasis, representing a promising nanotherapeutic formula for safe and efficient tumor therapy.

Increased matrix metalloproteinase-1 expression by coexposure to UVA and cigarette sidestream smoke and contribution of histone acetylation

BackgroundSkin is exposed to various environmental factors throughout life, and some of these factors are known to contribute to skin aging. Long-term solar UV exposure is a well-known cause of skin aging, as is cigarette smoke, which contains a number of chemicals. In this study, combined effect of UVA and cigarette sidestream smoke (CSS) on matrix metalloproteinase-1 (MMP-1) induction was investigated. MMP-1 is the main protease that initiates collagen type I fiber fragmentation in human skin and is associated with aging.ResultsCombined exposure to UVA and CSS enhanced MMP-1 induction, accompanied by collagen type I (COL1A1) gene suppression. The basal expression of MMP-1 was higher in senescent cells than in normal cells, with a pronounced increase after coexposure to UVA and CSS. UVA irradiation resulted in global histone H3 acetylation, and we considered this was responsible for the MMP-1 upregulation. Histone deacetylase inhibitors, sodium acetate, propionate, and butyrate, all enhanced the CSS-induced MMP-1 according to the degree of histone acetylation.ConclusionThese results suggest that UVA and CSS additively induce MMP-1, which may lead to skin aging, and that such combined effect may further promote aging in aged skin. UVA-induced histone acetylation may contribute to MMP-1 induction.

Deployment and transcriptional evaluation of nitisinone, an FDA-approved drug, to control bed bugs.

Bed bugs are blood-feeders that rapidly proliferate into large indoor infestations. Their bites can cause allergies, secondary infections and psychological stress, among other problems. Although several tactics for their management have been used, bed bugs continue to spread worldwide wherever humans reside. This is mainly due to human-mediated transport and their high resistance to several classes of insecticides. New treatment options with novel modes of action are required for their control. In this study, we evaluated the use of nitisinone (NTBC), an FDA-approved drug, for bed bug control in an insecticide-susceptible (HH) and an insecticide-resistant (CIN) population. Although NTBC was lethal to both populations when administered orally or applied topically in very low doses, we observed a slight but significant resistance in the CIN population. Transcriptomic analysis in both populations indicated that NTBC treatment elicited a broad suppression of genes associated with RNA post-transcriptional modifications, translation, endomembrane system, protein post-translational modifications and protein folding. The CIN population exhibited higher adenosine triphosphate (ATP) production and xenobiotic detoxification. Feeding studies on a mouse model suggest that NTBC could be used as a control method of bed bugs by host treatment. The results indicate that NTBC can be used as a new active ingredient for bed bug control by topical or oral treatment and shed light on the molecular mechanisms of suppressed tyrosine metabolism following NTBC treatment. © 2025 Society of Chemical Industry.

Performance analysis of Leica Biosystems p16 monoclonal antibody in oropharyngeal squamous cell carcinoma

BackgroundHead and neck squamous cell carcinoma (HNSCC) is the sixth leading cause of cancer death globally, with newly diagnosed oropharyngeal squamous cell carcinoma (OPSCC) cases rising to 54,000 in the US alone in the year 2022. Recently, human papilloma virus (HPV) infection was more prevalent in OPSCC patients than the traditionally known carcinogens such as tobacco or alcohol. HPV 16 is the most common causative HPV strain, which is found in 5–10% of HNSCC patients. HPV 16’s E6 and E7 oncoproteins bind and inactivate p53 and retinoblastoma (Rb) tumor-suppressing genes. This causes aberrant over-expression of the cell cycle inhibitor gene, p16, leading to tumorigenesis. Leica Biosystems (LBS) has developed a p16 antibody (6H12 clone) for qualitatively identifying the p16 protein in formalin-fixed paraffin-embedded (FFPE) tissue by immunohistochemical staining. This method comparison study tested the concordance rates between ready-to-use (RTU) LBS p16/LBS RTU p16 antibody and Roche Tissue Diagnostics (RTD) CINtec p16 Histology immunohistochemical (IHC) assays by measuring overall agreement (OA), average positive agreement (APA), and average negative agreement (ANA) rates in 170 OPSCC FFPE cases. Interobserver agreement of the 2 assays and LBS RTU p16 comparison with the standard HPV molecular assays (DNA ISH and PCR) were also assessed.MethodsOne hundred and seventy (170) unique oropharyngeal cancer cases were stained for qualitative analysis by the LBS p16 antibody on BOND III. This assay was compared to Ventana’s RTD E6H4 (CINtec) clone on Benchmark XT. A stained core was considered p16 positive if the Histoscore (H score) was ≥ 140 and negative if H < 140.ResultsAcross the pathologists, the agreement rate between the 2 assays ranged from OA, 98.7 – 98.8%, ANA, 98.8 -98.9%, and APA, 98.6%. For LBS RTU p16, the interobserver agreement was OA, 98.7%, ANA, 98.8%, and APA, 98.6%; while for RTD CINtec p16 assay, the concordance was OA, 98.7%, ANA, 98.8% and APA, 98.6%. In comparison to the HPV molecular testing, DNA ISH, and PCR, across pathologists, LBS p16 clone (LBS RTU p16) showed a concordance rate of 85.8-86.9% and 87.6-88.8%, respectively.ConclusionLBS p16 monoclonal antibody demonstrated high concordance with CINtec p16 IHC assay across all the endpoints, suggesting a potential use of LBS RTU p16 clone in detecting p16 protein in oropharyngeal cancer cases.

Resveratrol as a BCL6 natural inhibitor suppresses germinal center derived Non-Hodgkin lymphoma cells growth.

Non-Hodgkin lymphomas (NHL), including diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma (BL), and follicular lymphoma (FL), predominantly arise from B cells undergoing germinal center (GC) reactions. The transcriptional repressor B-cell lymphoma 6 (BCL6) is indispensable for GC formation and contributes to lymphomagenesis via its BTB domain-mediated suppression of target genes. Dysregulation of BCL6 underpins the pathogenesis of GC-derived NHL. While pharmacological targeting the BCL6-BTB domain has shown therapeutic promise, natural product-based inhibitors remain underexplored. In this study, resveratrol, a polyphenolic compound derived from grapes, was identified as a potent BCL6 inhibitor through a comprehensive screen of traditional Chinese medicine monomers using Homogeneous Time-Resolved Fluorescence (HTRF) assay. As a BCL6 natural inhibitor, resveratrol effectively disrupted the BCL6/SMRT interaction, reactivated suppressed gene expression, and inhibited the proliferation of GC-derived NHL cells. It also exhibited synergistic efficacy when combined with EZH2 and PRMT5 inhibitors. In vivo, resveratrol suppressed GC formation, reduced follicular helper T-cell frequencies, impaired class-switch recombination, and disrupted immunoglobulin affinity maturation. Furthermore, it markedly inhibited the progression of GC-derived NHL in animal models. Our findings demonstrate that resveratrol functions as a natural BCL6 inhibitor with significant therapeutic potential for the treatment of GC-derived NHL.

Hsa-miR-548d-3p: a potential microRNA to target nucleocapsid and/or capsid genes in multiple members of the Flaviviridae family.

Flaviviridae comprise a group of enveloped, positive-stranded RNA viruses that are mainly transmitted through either mosquitoes or tick bites and/or contaminated blood, blood products, or other body secretions. These viruses cause diseases ranging from mild to severe and are considered important human pathogens. MicroRNAs (miRNAs) are non-coding molecules involved in growth, development, cell proliferation, protein synthesis, apoptosis, and pathogenesis. These small molecules are even being used as gene suppressors in antiviral therapeutics, inhibiting viral replication. In the current study, we used bioinformatic tools to predict a possible miRNA sequence that could be complementary to the nucleocapsid (NP) and/or capsid (CP) gene of the Flaviviridae family and provide an inhibitory solution. Bioinformatics is a field of science that includes tremendous computational analysis, logarithms, and sequence alignments. To predict the right alignments between miRNA and viral mRNA genomes, we used computational databases such as miRBase, NCBI, and Basic Alignment Search Tool-nucleotides (BLAST-n). Of the 2,600 mature miRNAs, hsa-miR-548d-3p revealed complementary sequences with the flavivirus capsid gene and bovine viral diarrhea virus (BVDV) capsid gene and was selected as a possible candidate to inhibit flaviviruses. Although more detailed in vitro and in vivo studies are required to test the possible inhibitory effects of hsa-miR-548d-3p against flaviviruses, this computational study may be the first step to study further, developing a novel therapeutic for lethal viruses within the Flaviviridae family using suggested candidate miRNAs.

Tomato Defenses Under Stress: The Impact of Salinity on Direct Defenses Against Insect Herbivores.

Abiotic stressors, such as salt stress, can reduce crop productivity, and when combined with biotic pressures, such as insect herbivory, can exacerbate yield losses. However, salinity-induced changes to plant quality and defenses can in turn affect insect herbivores feeding on plants. This study investigates how salinity stress in tomato plants (Solanum Lycopersicum cv. Better Boy) impacts the behavior and performance of a devastating insect pest, the tomato fruitworm caterpillar (Helicoverpa zea). Through choice assays and performance experiments, we demonstrate that salt-stressed tomato plants are poor hosts for H. zea, negatively affecting caterpillar feeding preferences and growth rates. While changes in plant nutritional quality were observed, the primary factor influencing insect performance appears to be direct ionic toxicity, which significantly impairs multiple life history parameters of H. zea including survival, pupation, adult emergence, and fecundity. Plant defense responses show complex interactions between salt stress and herbivory, with two proteinase inhibitor genes - PIN2 and AspPI, showing a higher induced response to insect herbivory under salt conditions. However, plant defenses do not seem to be the main driver of reduced caterpillar performance on salt-treated plants. Furthermore, we report reduced oviposition by H. zea moths on salt-treated plants, which was correlated with altered volatile emissions. Our findings reveal that H. zea exhibits optimal host selection behaviours for both larval feeding and adult oviposition decisions, which likely contribute to its success as an agricultural pest. This research provides insights into the complex interactions between abiotic stress, plant physiology, and insect behaviour, with potential implications for pest management strategies in saline agricultural environments.

Targeting DOT1L and EZH2 synergizes in breaking the germinal center identity of Diffuse Large B-cell Lymphoma.

Differentiation of antigen-activated B cells into pro-proliferative germinal center (GC) B cells depends on the activity of the transcription factors MYC and BCL6, and the epigenetic writers DOT1L and EZH2. GCB-like Diffuse Large B Cell Lymphomas (GCB-DLBCLs) arise from GCB cells and closely resemble their cell of origin. Given the dependency of GCB cells on DOT1L and EZH2, we investigated the role of these epigenetic regulators in GCB-DLBCLs and observed that GCB-DLBCLs synergistically depend on the combined activity of DOT1L and EZH2. Mechanistically, inhibiting both enzymes led to enhanced derepression of PRC2 target genes compared to EZH2 single treatment, along with the upregulation of BCL6 target genes and suppression of MYC target genes. The sum of all these alterations results in a 'cell identity crisis', wherein GCB-DLBCLs lose their pro-proliferative GC identity and partially undergo PC differentiation, a state associated with poor survival. In support of this model, combined epi-drugging of DOT1L and EZH2 prohibited the outgrowth of human GCB-DLBCL xenografts in vivo. We conclude that the malignant behavior of GCB-DLBCLs strongly depends on DOT1L and EZH2 and that combined targeting of both epigenetic writers may provide an alternative differentiation-based treatment modality for GCB-DLBCL.

The pseudorabies virus UL13 protein kinase triggers phosphorylation of the RNA demethylase FTO, which is associated with FTO-dependent suppression of interferon-stimulated gene expression.

Alpha-ketoglutarate-dependent dioxygenase, also known as fat mass and obesity-associated protein (FTO), is an RNA demethylase that mediates the demethylation of N6,2-O-dimethyladenosine (m6Am) and N6-methyladenosine (m6A). Both m6Am and m6A are prevalent modifications in mRNA and affect different aspects of transcript biology, including splicing, nuclear export, translation efficiency, and degradation. The role of FTO during (herpes) virus infection remains largely unexplored. In this study, we show that the UL13 protein kinase of the alphaherpesvirus pseudorabies virus (PRV) triggers phosphorylation of FTO. In primary epithelial cells, depletion of FTO leads to increased expression of antiviral interferon-stimulated genes (ISGs) and UL13 triggers FTO-dependent suppression of ISG expression. Although PRV infection suppresses m6Am levels in host small nuclear RNA, this is independent of UL13. The current data highlight FTO as an important regulator of antiviral ISG expression and suggest that UL13-mediated phosphorylation of FTO may serve as a previously unrecognized viral strategy to suppress the antiviral interferon response.IMPORTANCERNA modification pathways play important roles in diverse cellular processes and virus life cycles. Although previous studies have demonstrated that alphaherpesviruses can substantially influence cellular RNA modifications, such as m6A, the impact on the m6Am epitranscriptome machinery remains largely unexplored. The present work reports that the UL13 protein kinase of pseudorabies virus (PRV), an alphaherpesvirus, mediates phosphorylation of the m6Am/m6A eraser FTO and that this correlates with a UL13- and FTO-dependent suppression of antiviral interferon-stimulated gene (ISG) expression. Furthermore, PRV infection leads to a pronounced reduction in m6Am levels in host snRNA and also induces phosphorylation of the m6Am writer PCIF1. These data highlight FTO as an important regulator of ISG expression and reveal that viral manipulation of FTO, such as UL13-induced phosphorylation of FTO, may serve as a previously unrecognized interferon evasion strategy.

Silicon reduces lead accumulation in Moso bamboo via immobilization and suppression of metal cation transporter genes in roots.

Lead (Pb) is a hazardous element that affects the growth and development of plants, while silicon (Si) is a beneficial element for alleviating the stress caused by heavy metals, including Pb. However, the mechanisms of Si reduce Pb accumulation in Moso bamboo remain unclear. In this study, physiological assessments and transcriptome analyses were conducted to investigate the interaction between Si and Pb. Our findings showed that Si application has no significant effect on alleviating Pb-induced inhibition of root elongation and dry weight in short-term and long-term experiments, respectively. However, it did rescue leaf yellowing, reduce Pb accumulation, particularly in the shoot. Pre-treatment with Si led to a reduction in Pb uptake, translocation, and accumulation, coupled with an increase in Pb fixation within the hemicellulose of the root cell wall, resulting in a lower Pb concentration in the cell sap. At the cellular level, Pb was found to be distributed in all cells of roots, and Si pre-treatment did not alter Pb distribution. Additionally, Si application down-regulated the expression of genes related to ABC and metal cation transporters. These findings indicate that Si reduces Pb accumulation in Moso bamboo by immobilizing Pb in the hemicellulose of root cell walls and down-regulating the expression of transporter genes involved in Pb uptake and transport.

Unveiling the potential anticancer activity of Spirulina maxima extract-nanoemulsion through in vitro and in vivo studies.

Being the second leading cause of death globally, cancer has been a long-standing and rapidly evolving focus of biomedical research and practice in the world. Recently, there has been growing interest in cyanobacteria. This focus is particularly evident in developing innovative anticancer treatments to reduce reliance on traditional chemotherapy. This study investigates the anticancer potential of the Spirulina maxima extract nanoemulsion (SMNE) technique to improve the delivery, stability, and solubility of the S. maxima extract (SME). SMNE, prepared in three concentrations (SMNEC1, SMNEC2, SMNEC3), was characterized and confirmed to successfully load SME into silica-coated nanoparticles. Cytotoxicity tests on HepG2 and MCF-7 cell lines revealed a significant reduction in cell viability after 48-hour SMNE treatment, with IC50 values of 1488µg/mL and 1721.936µg/mL, respectively. SMNE also demonstrated efficacy in inhibiting tumor growth in mice with Ehrlich ascites carcinoma, normalizing alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and reducing oxidative stress markers such as catalase (CAT) and malondialdehyde (MDA). Histopathological examination showed that SMNEC3-treated groups had almost normal liver architecture. Additionally, SMNE downregulated oncogenic miR-221-3p and miR-222-3p, activating cancer suppression genes p27 and PTEN. The study concludes that SMNE, with its anti-inflammatory and antioxidant properties and ability to modulate key miRNAs, enhances SME delivery and shows promise as an effective cancer treatment.

Combined PARP14 inhibition and PD-1 blockade promotes cytotoxic T cell quiescence and modulates macrophage polarization in relapsed melanoma

BackgroundProgrammed cell death 1 (PD-1) signaling blockade by immune checkpoint inhibitors (ICI) effectively restores immune surveillance to treat melanoma. However, chronic interferon-gamma (IFNγ)-induced immune homeostatic responses in melanoma cells contribute...

Potential of lavender essential oil to inhibit tetracycline resistance and modulate gut microbiota in black soldier fly larvae.

The misuse of tetracycline in livestock farming leads to environmental residues that promote the proliferation of antibiotic resistance genes (ARGs), particularly tetracycline resistance (tet) genes. Black soldier fly (BSF) larvae, used for organic waste bioconversion, may carry tetracycline residues in their guts, raising concerns about ARG spread. To address this issue, plant-derived additives such as lavender essential oil (LEO) have been explored as alternative antibiotics. This study investigated the effects of LEO on tet gene suppression and gut microbiota modulation in BSF larvae. Results showed that oxytetracycline treatment increased tet gene relative abundance threefold compared to the control, reaching 1.13 ± 0.29 and enriched pathogens Klebsiella oxytoca and Enterobacter hormaechei. Conversely, LEO treatment (100 mg/kg) reduced tet gene abundance by 46.67 %, from 0.15 ± 0.02to 0.08 ± 0.02, and enhanced beneficial microorganisms like Leuconostoc pseudomesenteroides. Furthermore, LEO reduced tet gene relative abundance in oxytetracycline-treated larvae from 1.13 ± 0.29 to 0.49 ± 0.19 and 0.70 ± 0.11 in separate treatments. LEO modified fungal composition and nutrient pathways. Network analysis revealed that LEO promoted a more integrated and modular gut microbiota, enhancing functional specialization and resilience. These findings suggest LEO can mitigate ARGs in BSF larvae, offering a sustainable approach for antibiotic resistance management in organic waste recycling and livestock farming.

Effect of Phosphate Starvation on Gene Expression in Komagataella phaffii Cells.

Phosphorus is a key nutrient for all organisms. The study of phosphate metabolism and its regulation is important for understanding the evolutionary processes of regulatory systems in eukaryotic cells. The methylotrophic yeast Komagataella phaffii is an efficient producer organism, and it is actively used in biotechnological production. The high practical importance of K. phaffii has stimulated active research to find new tools to work with this yeast and optimize its cultivation conditions. In this work, we observed the effect of phosphate starvation on gene expression in K. phaffii at the transcriptome level. Phosphate starvation had a significant effect on general cell metabolism. K. phaffii cells demonstrated a response to this macronutrient deficiency through an altered gene expression of carbon and amino acid metabolism. We observed the activation of phosphate and polyphosphate metabolism gene expression. In this case, there was a suppression of ribosome biogenesis genes and genes involved in fatty acid beta-oxidation and translation processes.

MLLT3 Regulates Melanoma Stemness and Progression by Inhibiting HMGB1 Nuclear Entry and MAGEA1 M5C Modification

AbstractMelanoma stem cells are a kind of cells with self‐renewal and multi‐directional differentiation potential. They are one of the key factors in the occurrence, development and metastasis of melanoma. This study demonstrates that MLLT3 is a transcription factor that regulates the stemness and progression of melanoma. MLLT3 interacted with HMGB1 to inhibit its entry into the nucleus, MLLT3 interacted with YBX1 to inhibit its reading of m5C of MAGEA1, thereby inhibiting the mRNA stability of MAGEA1, and directly transcribed P53 to inhibit the stemness, proliferation and metastasis of melanoma cells. This study further explored the potential mechanism of the interaction between miR‐542‐3p/miR‐3922‐3p and MLLT3. Furthermore, the scRNA‐seq of melanoma cells with MLLT3 knock‐out resulted in important changes in cell subsets, activating the TP53 and MAPK pathways and transforming into stem cells. The results indicate that the transcription factor MLLT3 is a suppressor gene that regulates the stemness and progression of melanoma, and is expected to become a target for melanoma therapy.

Genome-Wide Analysis of the Metallocarboxypeptidase Inhibitor Family Reveals That AbMCPI8 Affects Root Development and Tropane Alkaloid Production in Atropa belladonna.

Atropa belladonna is a medicinal plant and an important source for the commercial production of tropane alkaloids (TAs), such as scopolamine and hyoscyamine, which are used clinically for their anticholinergic properties. In this study, we identified 16 metallocarboxypeptidase inhibitor (MCPI) genes from A. belladonna (AbMCPIs), which are grouped into three subgroups based on phylogenetic relationships and are distributed across 10 chromosomes. Promoter analysis showed that most cis-regulatory elements were related to defense and stress responses, such as drought, low-temperature, ABA (abscisic acid), GA (gibberellin), auxin, light and MeJA responsiveness. A gene encoding a putative metallocarboxypeptidase inhibitor (AbMCPI8) is cloned from A. belladonna and characterized. AbMCPI8 shows similar tissue expression pattern to TA biosynthesis genes such as AbPMT, AbAT4, AbTRI, etc., with exclusive expression in the roots. When AbMCPI8 is silenced by virus-induced gene silencing (VIGS), the root growth is markedly inhibited and the production of hyoscyamine and scopolamine is significantly reduced. Our findings indicate a positive role of AbMCPI8 in root development, which could positively affect TA production in A. belladonna.

Azadirachtin disrupts ecdysone signaling and alters sand fly immunity

BackgroundLeishmaniasis is a group of neglected vector-borne diseases transmitted by phlebotomine sand flies. Leishmania parasites must overcome various defenses in the sand fly midgut, including the insects’s immune response. Insect immunity is regulated by the ecdysone hormone, which binds to its nuclear receptor (EcR) and activates the transcription of genes involved in insect immunity. However, the role of ecdysone in sand fly immunity has never been studied. Phlebotomus perniciosus is a natural vector of Leishmania infantum; here, we manipulated its neuroendocrine system using azadirachtin (Aza), a natural compound known to affect ecdysone synthesis.MethodsPhlebotomus perniciosus larvae and adult females were fed on food containing either Aza alone or Aza plus ecdysone, and the effects on mortality and ecdysis were evaluated. Genes related to ecdysone signaling and immunity were identified in P. perniciosus, and the expression of antimicrobial peptides (AMPs), EcR, the ecdysone-induced genes Eip74EF and Eip75B, and the transcription factor serpent were analyzed using quantitative polymerase chain reaction (PCR).ResultsAza treatment inhibited molting of first-instar (L1) larvae to L2, with only 10% of larvae molting compared to 95% in the control group. Serpent and Eip74EF, attacin, defensin 1, and defensin 2 genes were downregulated by Aza treatment in larvae. Similarly, Aza-treated adult females also presented suppression of ecdysone signaling-related genes and the AMPs attacin and defensin 2. Notably, all gene repression caused by Aza was reversed by adding ecdysone concomitantly with Aza to the larval or female food, indicating that these genes are effective markers for ecdysone repression.ConclusionsThese results highlight the critical role of ecdysone in regulating the development and immunity of P. perniciosus, which potentially could interfere with Leishmania infection.Graphical