RESUMEN
OMA1 is an ATP-independent zinc metalloprotease essential for maintaining mitochondrial homeostasis and plays a vital role in tumorigenesis. Depending on the type of cancer, a decrease in OMA1 expression has been linked to a varying prognosis for patients. The role of OMA1 in human osteosarcoma (OS), one of the most prevalent malignant bone tumors, remains elusive. Here, we observed elevated OMA1 expression in OS tumor tissues from four patients with advanced OS. Knockout of OMA1 in OS cells significantly reduces OS tumor weight and size, and lung metastatic nodules in BALB/c nude mice. Immunohistochemistry analysis showed a significant decrease in Ki67 and an increase in Cleaved-caspase 3 in OMA1 knockout tumor samples. Mechanistically, we found that OMA1 deficiency increases the levels of PINK1 and Parkin and consequently induces excessive mitophagy, leading to increased apoptosis and reduced cell proliferation and invasion in OS cells. Specifically, OMA1 deficiency reduces the amount of cytosolic p53 and p53-associated cytosolic Parkin but increases mitochondrial p53, which may lead to enhanced apoptosis. Regarding the effect on cell proliferation and invasion, loss of OMA1 reduces mitochondrial ROS levels and increases cytosolic glycogen synthase kinase 3ß (GSK3ß) levels, thereby increasing interaction between GSK3ß and ß-catenin and then reducing cytosolic and nuclear ß-catenin. This contributes to reduced cell proliferation and migration in OMA1-deficient cells. Moreover, we found that ciclopirox (CPX), an antifungal drug, induces OMA1 self-cleavage and L-OMA1 degradation in cultured OS cells. CPX also reduces tumor development of control OS cells but not OMA1-deficient OS cells in mice. These findings strongly support the important role of OMA1 in OS tumorigenesis and suggest that OMA1 may be a valuable prognostic marker and a promising therapeutic target for OS.
Asunto(s)
Neoplasias Óseas , Carcinogénesis , Proliferación Celular , Metaloendopeptidasas , Ratones Endogámicos BALB C , Ratones Desnudos , Mitocondrias , Osteosarcoma , Osteosarcoma/patología , Osteosarcoma/metabolismo , Osteosarcoma/genética , Humanos , Animales , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos , Carcinogénesis/patología , Carcinogénesis/metabolismo , Carcinogénesis/genética , Línea Celular Tumoral , Ratones , Neoplasias Óseas/metabolismo , Neoplasias Óseas/patología , Neoplasias Óseas/genética , Metaloendopeptidasas/metabolismo , Metaloendopeptidasas/genética , Proliferación Celular/efectos de los fármacos , Apoptosis/efectos de los fármacos , Mitofagia/efectos de los fármacos , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , beta Catenina/metabolismo , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Masculino , Femenino , Proteínas Quinasas/metabolismo , Proteínas Quinasas/genética , Especies Reactivas de Oxígeno/metabolismoRESUMEN
OBJECTIVE: To explore the differences in ultra-processed food (UPF) consumption across different socioeconomic status (SES) levels. METHODS: Data on UPF consumption (grams/day) were derived from the 2017-2018 National Health and Nutrition Examination Survey. The analysis controlled for age, marital status, race, and sex. A restricted cubic spline (RCS) model was applied to examine the nonlinear response curve. RESULTS: UPF consumption increased with higher poverty income ratio (PIR), the ratio of household income to the established poverty line. Compared to the low PIR group, the medium group showed a non-significant increase (ß = 34.23[95%CI: -28.81, 97.28], p = 0.287), while the high group exhibited a significant increase (ß = 115.15[95%CI: 43.53, 186.76], p = 0.002). A linear positive correlation was observed in RCS analysis (p-nonlinear = 0.166, p-overall < 0.001). CONCLUSIONS: The study highlights that higher SES is associated with greater consumption of UPF in the US. The findings suggest that policy interventions should take SES into consideration.
RESUMEN
Biomolecular condensates are distinct subcellular structures with on-demand material states and dynamics in living cells. However, strategies for modulating their material states and physicochemical properties are lacking. Here, we report a chemical strategy for modulating the condensate states of intrinsically disordered proteins in bacterial Escherichia coli cells. This is achieved by noncanonical amino acid (DOPA) incorporation into model resilin-like proteins (RLPs) to endow autonomous oxidative and coordinative cross-linking mechanisms. Biogenesis of spherical gel-like condensates is achieved upon heterologous expression of the DOPA-incorporated RLP in the cells at 30 °C. We reveal that liquid-liquid phase separation underlies the formation of liquid condensates, and this liquid-like state is metastable and its dynamics is compromised by the oxidative and coordinative cross-linkings that ultimately drive the liquid-to-gel transition. Therefore, this study has deepened our understanding of biomolecular condensation and offers a new chemical strategy to expand the landscape of condensation phenotypes of living cells.
RESUMEN
AIMS: Population aging is a challenge that the whole world is facing, especially in China. This study aims to investigate the current distribution status of nursing homes in China using spatial epidemiology methods. DESIGN: Cross-sectional study in China. METHODS: The data were obtained from the Integrated Civil Affairs Government Service Platform 'China County Statistical Yearbook' for 2020 and the 'China City Statistical Yearbook' for 2020. Using global Moran's index to test the clustering of nursing homes, inter-group and intra-group Theil index was utilised to differentiate the sources of differences. The coupling coordination analysis was conducted to explore the coordination. Geographically weighted regression was utilised to investigate the impact of economic development and aging on nursing home resources. All analyses were conducted by Arcgis 10.8 and R Studio 4.3.2. RESULTS: Global Moran's index indicated that the distribution of nursing homes in China exhibited clustering. The Theil index values for institutions and beds at the national county were 0.32450 and 0.30675. However, upon comparing provinces and regions, it was found that the differences across the country mainly stem from within provinces (contribution rate: institutions 65.0%; beds 73.0%) and within regions (contribution rate: institutions 99.0%; beds 91.0%). The majority of districts and counties had a coupling coordination index of institutions and bed numbers, both of which were < 0.5. CONCLUSION: The development of nursing home resources in China has been rapid, generally presenting a balanced state, but further optimisation is needed. This study established a foundation for the targeted distribution of essential public services, focusing on nursing home healthcare resources tailored to the needs of older persons. IMPLICATIONS: The study underscored the urgent need for targeted elderly care policies, emphasising the optimisation of resource distribution to enhance the overall quality of care provided to the aging population. NO PATIENTS OR PUBLIC CONTRIBUTION: The study did not involve humans.
RESUMEN
Background: Recurrent spontaneous abortion (RSA) is a multifactorial disease, the exact causes of which are still unknown. Environmental, maternal, and genetic factors have been shown to contribute to this condition. The aim of this study was to investigate the presence of mutations in the ANXA4 gene in patients with RSA. Methods: Genomic DNA was extracted from 325 patients with RSA and 941 control women with a normal reproductive history for whole-exome sequencing (WES). The detected variants were annotated and filtered, and the pathogenicity of the variants was predicted through the SIFT online tool, functional enrichment analyses, Sanger sequencing validation, prediction of changes in protein structure, and evolutionary conservation analysis. Furthermore, plasmid construction, Western blotting, RT-qPCR, and cell migration, invasion and adhesion assays were used to detect the effects of ANXA4 mutations on protein function. Results: An ANXA4 mutation (p.G8D) in 1 of the 325 samples from patients with RSA (RSA-219) was identified through WES. This mutation was not detected in 941 controls or included in public databases. Evolutionary conservation analysis revealed that the amino acid residue affected by the mutation (p.G8D) was highly conserved among 13 vertebrate species, and the SIFT program and structural modeling analysis predicted that this mutation was harmful. Furthermore, functional assays revealed that this mutation could inhibit cell migration, invasion and adhesion. Conclusion: Our study suggests that an unreported novel ANXA4 mutation (p.G8D) plays an important role in the pathogenesis of RSA and may contribute to the genetic diagnosis of RSA.
RESUMEN
Water is essential to the formation of intracontinental granites, but its origin remains elusive. Here we address this scientific problem by analyzing D/H isotopes of apatites, hydrous minerals in Jurassic and Early Cretaceous granites and basalts from eastern North China Craton, where water was previously interpreted as derived from subducting slab. Results reveal extremely low δD values in pristine Early Cretaceous granitic (-203 to -127) and basaltic (-197 to -107) apatites, contrasting with relatively high δD values (-137 to -47) in Jurassic granites. Given the depth-dependent D/H isotopic fractionation during slab dehydration and high-water contents in coeval primitive mafic magmas, the Early Cretaceous magma water is attributed to the stagnant slab within the mantle transition zone. Secular change in the depth of water aligns with steepening of subducting Paleo-Pacific plate from Jurassic to Early Cretaceous, demonstrating the potential of apatite H isotopes in tracing water origin in granites and basalts.
RESUMEN
OBJECTIVE: The objective of this study was to provide an updated analysis of suicide characteristics in China from 2002 to 2021, with the aim of informing the development of evidence-based suicide prevention strategies. METHODS: The Ministry of Health-Vital Registration System (MOH-VR) provided the data on suicide mortality, which enabled us to examine the average annual percentage change (AAPC) in suicide rates using a Poisson regression model. RESULTS: Notably, there has been a significant decline in suicide rates observed in both urban and rural areas. In the early years of the study period, higher suicide rates were observed among females compared to males; however, a shift occurred after 2005, with male suicide rates surpassing those of females. Except for 2005, rural areas consistently exhibited higher suicide rates than urban areas. Furthermore, suicide rates exhibited an increasing trend with age, irrespective of gender or region. CONCLUSION: These findings highlight a decreasing trend in suicide rates in China over the past two decades, although gender and regional disparities persist. Going forward, sustained efforts in suicide prevention, with a specific focus on mental health, are warranted.
Asunto(s)
Población Rural , Suicidio , Población Urbana , Humanos , China/epidemiología , Masculino , Femenino , Suicidio/estadística & datos numéricos , Suicidio/tendencias , Adulto , Persona de Mediana Edad , Población Rural/estadística & datos numéricos , Adolescente , Adulto Joven , Población Urbana/estadística & datos numéricos , Anciano , Distribución por Sexo , Factores SexualesRESUMEN
P2-type Mn-based layered oxides have emerged as one of the most promising cathode materials for sodium-ion batteries owing to their advantages of facile preparation and high theoretical capacity. However, challenges such as phase transition and irreversible oxygen release during cycling often lead to rapid structural distortion and the formation of oxygen vacancies, ultimately resulting in rapid capacity decay. Herein, a covalency modulation strategy is adopted to address these challenges and successfully achieved a stable P2-type Mn-based layered oxide by introducing strong covalent NiâO bonds. The robust NiâO motif plays a crucial role in maintaining the rigidity of transition metal (TM) layered frameworks, which efficiently alleviates the structural distortion and degradation of the coordination environments of local TM sites, thereby achieving durable structural stiffness over extended cycles. In addition, the strong covalent NiâO bonds can also stabilize the local oxygen environment, effectively suppressing the irreversible oxygen release. Benefiting from these advancements, the as-designed Na0.6Mg0.15Mn0.7Ni0.15O2 cathode displays a full solid-solution behavior with a low volume change of only 0.9% and an enhanced reversibility of lattice oxygen redox (OR) reaction. This investigation emphasizes the crucial role of covalency modulation in regulating OR chemistry and structural integrity to achieve high-energy-density Mn-based layered oxides.
RESUMEN
Commelina communis L., a functional food and herbal plant in Asia, has been used against obesity, diabetes, and infections for centuries. A growing body of studies has demonstrated that indigestible polysaccharides are significant in obesity management. However, the structures and bioactivities of homogeneous polysaccharides from C. communis remain unclear. This study presented the structural characterization, simulated digestion, and human gut Bacteroides proliferation promotion activity of a novel homogeneous polysaccharide (CCB-3) from C. communis. The results showed that CCB-3 was an arabinoglucuronoxylan, primarily composed of arabinose, galactose, xylose, glucuronic acid (GlcA), and 4-O-methyl GlcA with a molecular weight (Mw) of 58.8 kDa. Following a 6-hour exposure to simulated gastrointestinal fluid, the Mw of CCB-3 remained unchanged, revealing that CCB-3 was an indigestible polysaccharide. Notably, CCB-3 could promote the proliferation of B. thetaiotaomicron, B. ovatus, and B. cellulosilyticus and produce short-chain fatty acids (SCFAs) and 1,2-propanediol. These findings might shed light on the discovery of polysaccharide-based leading compounds from C. communis against obesity.
RESUMEN
The species-rich cosmopolitan genus Rhododendron offers a good system for exploring the genomic mechanisms underlying adaptation to diverse habitats. Here, we report high-quality chromosomal-level genome assemblies of nine species, representing all five subgenera, different altitudinal distributions, and all flower color types of this genus. Further comprehensive genomic analyses indicate diverse adaptive strategies employed by Rhododendron, particularly adaptation to alpine and subalpine habitats by expansion/contraction of gene families involved in pathogen defense and oxidative phosphorylation, genomic convergent evolution, and gene copy-number variation. The convergent adaptation to high altitudes is further shown by population genomic analysis of R. nivale from the Himalaya-Hengduan Mountains. Moreover, we identify the genes involved in the biosynthesis of anthocyanins and carotenoids, which play a crucial role in shaping flower color diversity and environmental adaptation. Our study is significant for comprehending plant adaptive evolution and the uneven distribution of species diversity across different geographical regions.
Asunto(s)
Adaptación Fisiológica , Genoma de Planta , Rhododendron , Rhododendron/genética , Adaptación Fisiológica/genética , Filogenia , Evolución Molecular , Genómica/métodos , Flores/genética , Variaciones en el Número de Copia de ADN/genética , Carotenoides/metabolismo , Antocianinas/biosíntesis , Antocianinas/metabolismo , Antocianinas/genética , Especificidad de la EspecieRESUMEN
Facilitated by an electron donor-acceptor (EDA) complex, an efficient ß-trifluoromethylation and perfluoroalkylation of enamides with Togni reagent or perfluoroalkyl iodides is presented under transition-metal-free, photocatalyst-free and mild reaction conditions. Notably, using this photocatalyst-free strategy, direct trifluoromethylation and perfluoroalkylation of quinoxalin-2(1H)-one derivatives was also achieved via a photoactive electron donor-acceptor complex.
RESUMEN
Recombinant elastin-like polypeptides (ELPs) have emerged as an attractive nanoplatform for drug delivery due to their tunable genetically encoded sequence, biocompatibility, and stimuli-responsive self-assembly behaviors. Here, we designed and biosynthesized an HER2 (human epidermal growth factor receptor 2)-targeted affibody-ELP fusion protein (Z-ELP), which was subsequently conjugated with monomethyl auristatin E (MMAE) to build a protein-drug conjugate (Z-ELP-M). Due to its thermal response, Z-ELP-M can immediately self-assemble into a nanomicelle at physiological temperature. Benefiting from its active targeting and nanomorphology, Z-ELP-M exhibits enhanced cellular internalization and deep tumor penetration in vitro. Moreover, Z-ELP-M shows excellent tumor targeting and superior antitumor efficacy in HER2-positive ovarian cancer, demonstrating a relative tumor growth inhibition of 104.6%. These findings suggest that an affibody-functionalized elastin-like peptide-drug conjugate nanomicelle is an efficient strategy to improve antitumor efficacy and biosafety in cancer therapy.
Asunto(s)
Elastina , Neoplasias Ováricas , Receptor ErbB-2 , Femenino , Humanos , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/patología , Elastina/química , Animales , Receptor ErbB-2/metabolismo , Ratones , Micelas , Oligopéptidos/química , Oligopéptidos/farmacología , Línea Celular Tumoral , Antineoplásicos/farmacología , Antineoplásicos/química , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/farmacología , Sistemas de Liberación de Medicamentos/métodos , Péptidos/química , Péptidos/farmacología , Ratones Desnudos , Ratones Endogámicos BALB CRESUMEN
BACKGROUND: Cervical and upper thoracic esophageal cancer (ESCA) presents treatment challenges due to limited clinical evidence. This multi-center study (ChC&UES) explores radical radio(chemo)therapy efficacy and safety, especially focusing on radiation dose. METHOD: We retrospectively analyzed clinical data from 1,422 cases across 8 medical centers. According to the radiation dose for primary gross tumor, patients were divided into standard dose radiotherapy (SD, 50-55 Gy) or high dose (HD, > 55 Gy) radiotherapy. HD was further subdivided into conventional- high-dose group (HD-conventional, 55-63 Gy) and ultra-high-dose group (HD-ultra, ≥ 63 Gy). Primary outcome was Overall Survival (OS). RESULTS: The median OS was 33.0 months (95% CI: 29.401-36.521) in the whole cohort. Compared with SD, HD shown significant improved survival in cervical ESCA in Kaplan-Meier (P = 0.029) and cox multivariate regression analysis (P = 0.024) while shown comparable survival in upper thoracic ESCA (P = 0.735). No significant difference existed between HD-conventional and HD-ultra in cervical (P = 0.976) and upper thoracic (P = 0.610) ESCA. Incidences of radiation esophagitis and pneumonia from HD were comparable to SD (P = 0.097, 0.240), while myosuppression risk was higher(P = 0.039). The Bonferroni method revealed that, for both cervical and upper thoracic ESCA, HD-ultra enhance the objective response rate (ORR) compared to SD (P < 0.05). CONCLUSION: HD radiotherapy benefits cervical but not upper thoracic ESCA, while increasing bone marrow suppression risk. Further dose escalating (≥ 63 Gy) doesn't improve survival but enhances ORR.
Asunto(s)
Quimioradioterapia , Neoplasias Esofágicas , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada , Humanos , Estudios Retrospectivos , Neoplasias Esofágicas/terapia , Neoplasias Esofágicas/mortalidad , Neoplasias Esofágicas/radioterapia , Neoplasias Esofágicas/patología , Femenino , Persona de Mediana Edad , Masculino , Quimioradioterapia/métodos , Anciano , Radioterapia de Intensidad Modulada/métodos , Radioterapia de Intensidad Modulada/efectos adversos , Adulto , Radioterapia Conformacional/métodos , Tasa de Supervivencia , Anciano de 80 o más Años , PronósticoRESUMEN
OBJECTIVES: To investigate the changes in the serum levels of oxidized phospholipids (OxPLs) and endothelial nitric oxide synthase (eNOS) and their association with coronary artery disease (CAL) in children in the acute stage of Kawasaki disease (KD), as well as the clinical significance of OxPLs and eNOS. METHODS: A prospective study was conducted on 95 children in the acute stage of KD (KD group). According to the presence of absence of CAL, the KD group was further divided into a CAL subgroup and a non-CAL (NCAL) subgroup. Thirty children with fever due to lower respiratory tract infection were enrolled as the fever group. Thirty healthy children who underwent physical examination were enrolled as the healthy control group. The above groups were compared in terms of general information and serum levels of OxPLs, eNOS and other laboratory indexes, and the correlation between OxPLs level and eNOS level was analyzed. RESULTS: The KD group had a significantly higher level of OxPLs and a significantly lower level of eNOS compared with the fever group and the healthy control group (P<0.05). After treatment, the children with KD had a significantly decreased OxPLs level and a significantly increased eNOS level (P<0.05). Compared with the NCAL subgroup, the CAL subgroup had a significantly higher level of OxPLs and a significantly lower level of eNOS (P<0.05). Among the children of KD, the level of OxPLs was negatively correlated with that of eNOS (rs=-0.353, P<0.05). CONCLUSIONS: Serum OxPLs and eNOS in the acute stage of KD may be involved in the development of CAL in children with KD, and therefore, they may be used as the biomarkers to predict CAL in these children.
Asunto(s)
Síndrome Mucocutáneo Linfonodular , Óxido Nítrico Sintasa de Tipo III , Fosfolípidos , Humanos , Síndrome Mucocutáneo Linfonodular/sangre , Masculino , Femenino , Óxido Nítrico Sintasa de Tipo III/sangre , Preescolar , Lactante , Estudios Prospectivos , Enfermedad Aguda , Fosfolípidos/sangre , Oxidación-Reducción , Niño , Enfermedad de la Arteria Coronaria/sangre , Enfermedad de la Arteria Coronaria/etiologíaRESUMEN
The nanodrug delivery system-based nasal spray (NDDS-NS) can bypass the blood-brain barrier and deliver drugs directly to the brain, offering unparalleled advantages in the treatment of central nervous system (CNS) diseases. However, the current design of NNDS-NS is excessively focused on mucosal absorption while neglecting the impact of nasal deposition on nose-to-brain drug delivery, resulting in an unsatisfactory nose-to-brain delivery efficiency. In this study, the effect of the dispersion medium viscosity on nasal drug deposition and nose-to-brain delivery in NDDS-NS was elucidated. The optimized formulation F5 (39.36 mPa·s) demonstrated significantly higher olfactory deposition fraction (ODF) of 23.58%, and a strong correlation between ODF and intracerebral drug delivery (R2 = 0.7755) was observed. Building upon this understanding, a borneol-modified lipid nanoparticle nasal spray (BLNP-NS) that combined both nasal deposition and mucosal absorption was designed for efficient nose-to-brain delivery. BLNP-NS exhibited an accelerated onset of action and enhanced brain targeting efficiency, which could be attributed to borneol modification facilitating the opening of tight junction channels. Furthermore, BLNP-NS showed superiority in a chronic migraine rat model. It not only provided rapid relief of migraine symptoms but also reversed neuroinflammation-induced hyperalgesia. The results revealed that borneol modification could induce the polarization of microglia, regulate the neuroinflammatory microenvironment, and repair the neuronal damage caused by neuroinflammation. This study highlights the impact of dispersion medium viscosity on the nose-to-brain delivery process of NDDS-NS and serves as a bridge between the formulation development and clinical transformation of NDDS-NS for the treatment of CNS diseases.
Asunto(s)
Encéfalo , Canfanos , Lípidos , Nanopartículas , Rociadores Nasales , Ratas Sprague-Dawley , Animales , Nanopartículas/química , Ratas , Lípidos/química , Encéfalo/metabolismo , Canfanos/química , Canfanos/administración & dosificación , Canfanos/farmacología , Masculino , Administración Intranasal , Sistemas de Liberación de Medicamentos , Enfermedades del Sistema Nervioso Central/tratamiento farmacológico , Mucosa Nasal/metabolismo , Mucosa Nasal/efectos de los fármacos , Tamaño de la PartículaRESUMEN
Mitochondrial DNA (mtDNA) is pivotal for mitochondrial morphology and function. Upon mtDNA damage, mitochondria undergo quality control mechanisms, including fusion, fission, and mitophagy. Real-time monitoring of mtDNA enables a deeper understanding of its effect on mitochondrial function and morphology. Controllable induction and real-time tracking of mtDNA dynamics and behavior are of paramount significance for studying mitochondrial function and morphology, facilitating a deeper understanding of mitochondria-related diseases. In this work, a fluorescent platinum complex was designed and developed that not only induces mitochondrial DNA (mtDNA) aggregation but also triggers mitochondrial autophagy (mitophagy) through the MDV pathway for damaged mtDNA clearance in living cells. Additionally, this complex allows for the real-time monitoring of these processes. This complex may serve as a valuable tool for studying mitochondrial microautophagy and holds promise for broader applications in cellular imaging and disease research.
Asunto(s)
ADN Mitocondrial , Colorantes Fluorescentes , Mitofagia , ADN Mitocondrial/metabolismo , Humanos , Colorantes Fluorescentes/química , Mitocondrias/metabolismo , Platino (Metal)/química , Células HeLaRESUMEN
Visible-light-induced three-component 1,2-alkyl-arylation of alkenes and alkyl radical addition/cyclization of acrylamides have been realized via a photocatalytic halogen-atom transfer (XAT) process. This metal-free protocol utilizes readily available tertiary alkylamine as both an electron donor and an XAT reagent for the activation of alkyl halides using naphthalimide (NI)-based organic photocatalysts. This process features broad substrate scope and good functional group tolerance under mild conditions, and could be effectively applied to a variety of medicinally relevant substrates.
RESUMEN
G-quadruplex (G4) structures play integral roles in modulating biological functions and can be regulated by small molecules. The MYC gene is critical during tumor initiation and malignant progression, in which G4 acts as an important modulation motif. Herein, we reported the MYC promoter G4 recognized by a platinum(II) compound Pt-phen. Two Pt-phen-MYC G4 complex structures in 5 mM K+ were determined by NMR. The Pt-phen first strongly binds the 3'-end of MYC G4 to form a 1:1 3'-end binding complex and then binds 5'-end to form a 2:1 complex with more Pt-phen. In the complexes, the Pt-phen molecules are well-defined and stack over four bases at the G-tetrad for a highly extensive π-π interaction, with the Pt atom aligning with the center of the G-tetrad. The flanking residues were observed to rearrange and cover on top of Pt-phen to stabilize the whole complex. We further demonstrated that Pt-phen targets G4 DNA in living cells and represses MYC gene expression in cancer cells. Our work elucidated the structural basis of ligand binding to MYC promoter G4. The platinum compound bound G4 includes multiple complexes formation, providing insights into the design of metal ligands targeting oncogene G4 DNA.
Asunto(s)
G-Cuádruplex , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas c-myc , G-Cuádruplex/efectos de los fármacos , Humanos , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/química , ADN/química , ADN/metabolismo , Compuestos de Platino/química , Genes myc , Platino (Metal)/químicaRESUMEN
HLA-DPB1*1553:01 differs from HLA-DPB1*09:01:01:01 by one nucleotide in exon 3.