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1.
J Microbiol Biol Educ ; : e0003423, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38874323

RESUMO

Misinformation regarding vaccine science decreased the receptiveness to COVID-19 vaccines, exacerbating the negative effects of the COVID-19 pandemic on society. To mitigate the negative societal impact of the COVID-19 pandemic, impactful and creative science communication was needed, yet little research has explored how to encourage COVID-19 vaccine acceptance and address misconceptions held by non-Science, Technology, Engineering and Mathematics majors (referred to as non-majors). We have previously demonstrated that including expert guest lectures in the vaccine module in the non-major introductory biology course helps combat students' vaccine hesitancy. In the present study, we further address how learning about vaccines impacts student knowledge and impressions of the COVID-19 vaccines through a podcast assignment. As a part of this assignment, non-majors created podcasts to address COVID-19 vaccine misconceptions of their choice. We coded pre and post, open-ended essay reflections (n = 40) to assess non-majors' knowledge and impressions of the COVID-19 vaccines. Non-majors' impressions of the vaccines improved following the podcast assignment with more than three times as many students reporting a positive view of the assignment than negative views. Notably, eight of the nine interviewed students still ended the course with misconceptions about the COVID-19 vaccines, such as the vaccines being unnecessary or causing fertility issues. In a post semi-structured interview following this assignment, students (n = 7) discussed the impact of looking into the specific misconceptions related to COVID-19 vaccines themselves, including improved science communication skills and understanding of different perspectives. Thus, podcasts can provide opportunities for students to improve engagement in valuable societal topics like vaccine literacy in the non-majors classroom.

2.
Cancer Discov ; 14(4): 683-689, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38571435

RESUMO

Research on precancers, as defined as at-risk tissues and early lesions, is of high significance given the effectiveness of early intervention. We discuss the need for risk stratification to prevent overtreatment, an emphasis on the role of genetic and epigenetic aging when considering risk, and the importance of integrating macroenvironmental risk factors with molecules and cells in lesions and at-risk normal tissues for developing effective intervention and health policy strategies.


Assuntos
Lesões Pré-Cancerosas , Humanos , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/patologia , Fatores de Risco
3.
Artigo em Inglês | MEDLINE | ID: mdl-38600824

RESUMO

Surface modification is an attractive strategy to adjust the properties of polymer membranes. Unfortunately, predictive structure-processing-property relationships between the modification strategies and membrane performance are often unknown. One possibility to tackle this challenge is the application of data-driven methods such as machine learning. In this study, we applied machine learning methods to data sets containing the performance parameters of modified membranes. The resulting machine learning models were used to predict performance parameters, such as the pure water permeability and the zeta potential of membranes modified with new substances. The predictions had low prediction errors, which allowed us to generalize them to similar membrane modifications and processing conditions. Additionally, machine learning methods were able to identify the impact of substance properties and process parameters on the resulting membrane properties. Our results demonstrate that small data sets, as they are common in materials science, can be used as training data for predictive machine learning models. Therefore, machine learning shows great potential as a tool to expedite the development of high-performance membranes while reducing the time and costs associated with the development process at the same time.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38155004

RESUMO

Peripheral ameloblastoma (PA) is a rare variant of ameloblastoma that presents as a slow-growing, painless mass in the gingival tissues or alveolar mucosa. It shares histologic features with conventional ameloblastoma but is less invasive and aggressive. This case report describes a 51-year-old female with a PA that simultaneously or subsequently developed underlying squamous cell papilloma after mandibular third molar extraction. Clinical examination revealed a pedunculated gingival lesion mimicking squamous cell papilloma. Histopathologic examination confirmed PA underlying squamous cell papilloma after an excisional biopsy. Imaging revealed mild bone resorption, leading to a further soft tissue excision and minimal osteoectomy to rule out intraosseous involvement. The patient remained asymptomatic without signs of recurrence in the 1-year follow-up. PA diagnosis can be challenging due to its clinical resemblance to other gingival lesions and histopathologic features. Treatment typically involves surgical excision, with long-term follow-up recommended due to possible recurrence and malignant transformation.


Assuntos
Ameloblastoma , Papiloma , Feminino , Humanos , Pessoa de Meia-Idade , Ameloblastoma/diagnóstico por imagem , Ameloblastoma/cirurgia , Dente Serotino/cirurgia , Diagnóstico Diferencial , Papiloma/diagnóstico , Biópsia
5.
Cell ; 186(25): 5620-5637.e16, 2023 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-38065082

RESUMO

Colorectal cancer exhibits dynamic cellular and genetic heterogeneity during progression from precursor lesions toward malignancy. Analysis of spatial multi-omic data from 31 human colorectal specimens enabled phylogeographic mapping of tumor evolution that revealed individualized progression trajectories and accompanying microenvironmental and clonal alterations. Phylogeographic mapping ordered genetic events, classified tumors by their evolutionary dynamics, and placed clonal regions along global pseudotemporal progression trajectories encompassing the chromosomal instability (CIN+) and hypermutated (HM) pathways. Integrated single-cell and spatial transcriptomic data revealed recurring epithelial programs and infiltrating immune states along progression pseudotime. We discovered an immune exclusion signature (IEX), consisting of extracellular matrix regulators DDR1, TGFBI, PAK4, and DPEP1, that charts with CIN+ tumor progression, is associated with reduced cytotoxic cell infiltration, and shows prognostic value in independent cohorts. This spatial multi-omic atlas provides insights into colorectal tumor-microenvironment co-evolution, serving as a resource for stratification and targeted treatments.


Assuntos
Neoplasias Colorretais , Instabilidade de Microssatélites , Microambiente Tumoral , Humanos , Instabilidade Cromossômica/genética , Neoplasias Colorretais/patologia , Perfilação da Expressão Gênica , Quinases Ativadas por p21/genética , Filogenia , Mutação , Progressão da Doença , Prognóstico
6.
ACS ES T Eng ; 3(11): 1694-1705, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37969427

RESUMO

Photocatalytic advanced oxidation processes (AOPs) promise a chemical-free route to energy-efficient degradation of waterborne micropollutants if long-standing mass transfer and light management issues can be overcome. Herein, we developed a dual-porous photocatalytic system consisting of a mesoporous (i.e., 2-50 nm pores) TiO2 (P25) photocatalyst supported on macroporous (i.e., >50 nm pores) fused quartz fibers (P25/QF). Our reusable photocatalytic AOP reduces chemical consumption and exhibits excellent energy efficiency, demonstrated by degrading various pharmaceutical compounds (acetaminophen, sulfamethoxazole, and carbamazepine) in natural waters with electrical energy per order (EEO) values of 4.07, 0.96, and 1.35 kWh/m3, respectively. Compared to the conventional H2O2/UVC AOP, our photocatalytic AOP can treat water without chemical additives while reducing energy consumption by over 2800%. We examine these improvements based on mass transport and optical (UVA and UVC) transmittance and demonstrate that the enhancements scale with increasing flow rate.

7.
Extracell Vesicles Circ Nucl Acids ; 4(2): 195-217, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37840781

RESUMO

Although extracellular vesicles (EVs) were discovered over 40 years ago, there has been a resurgence of interest in secreted vesicles and their attendant cargo as novel modes of intracellular communication. In addition to vesicles, two amembranous nanoparticles, exomeres and supermeres, have been isolated and characterized recently. In this rapidly expanding field, it has been challenging to assign cargo and specific functions to a particular carrier. Refinement of isolation methods, well-controlled studies, and guidelines detailed by Minimal Information for Studies of Extracellular Vesicles (MISEV) are being employed to "bring order to chaos." In this review, we will briefly summarize three types of extracellular carriers - small EVs (sEVs), exomeres, and supermeres - in the context of colorectal cancer (CRC). We found that a number of GPI-anchored proteins (GPI-APs) are overexpressed in CRC, are enriched in exosomes (a distinct subset of sEVs), and can be detected in exomeres and supermeres. This affords the opportunity to elaborate on GPI-AP biogenesis, modifications, and trafficking using DPEP1, a GPI-AP upregulated in CRC, as a prime example. We have cataloged the GPI-anchored proteins secreted in CRC and will highlight features of select CRC-associated GPI-anchored proteins we have detected. Finally, we will discuss the remaining challenges and future opportunities in studying these secreted GPI-APs in CRC.

8.
J Am Dent Assoc ; 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37877928
9.
Sci Signal ; 16(803): eadh4210, 2023 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-37725664

RESUMO

Alternative splicing regulates gene expression and functional diversity and is often dysregulated in human cancers. Here, we discovered that the long noncoding RNA (lncRNA) MIR99AHG regulated alternative splicing to alter the activity of a chromatin remodeler and promote metastatic behaviors in colorectal cancer (CRC). MIR99AHG was abundant in invasive CRC cells and metastatic tumors from patients and promoted motility and invasion in cultured CRC cells. MIR99AHG bound to and stabilized the RNA splicing factor PTBP1, and this complex increased cassette exon inclusion in the mRNA encoding the chromatin remodeling gene SMARCA1. Specifically, MIR99AHG altered the nature of PTBP1 binding to the splice sites on intron 12 of SMARCA1 pre-mRNA, thereby triggering a splicing switch from skipping to including exon 13 to produce the long isoform, SMARCA1-L. SMARCA1, but not SMARCA1-L, suppressed invadopodia formation, cell migration, and invasion. Analysis of CRC samples revealed that the abundance of MIR99AHG transcript positively correlated with that of SMARCA1-L mRNA and PTBP1 protein and with poor prognosis in patients with CRC. Furthermore, TGF-ß1 secretion from cancer-associated fibroblasts increased MIR99AHG expression in CRC cells. Our findings identify an lncRNA that is induced by cues from the tumor microenvironment and that interacts with PTBP1 to regulate alternative splicing, potentially providing a therapeutic target and predictive biomarker for metastatic CRC.


Assuntos
Neoplasias Colorretais , Podossomos , RNA Longo não Codificante , Humanos , Processamento Alternativo , Cromatina , Neoplasias Colorretais/genética , Ribonucleoproteínas Nucleares Heterogêneas/genética , Proteína de Ligação a Regiões Ricas em Polipirimidinas/genética , Splicing de RNA , RNA Longo não Codificante/genética , Microambiente Tumoral
10.
Clin Exp Dent Res ; 9(5): 887-893, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37759423

RESUMO

OBJECTIVE: Periodic examination of the head and neck includes screening for oral cancer, which is largely performed in dental offices by vigilant oral healthcare providers. The aim of this study was to assess practice patterns among Virginia dentists in performing head and neck exams and the referral rates of biopsies after completion of head and neck exams. We hypothesized that not all dentists perform head and neck exams and there is a difference between dentists who refer patients for a biopsy and those that perform biopsies. METHODS: General dentists and dental specialists who are members of the Virginia Dental Association were invited to participate in a cross-sectional survey study through REDCap to self-report their head and neck exam protocols. RESULTS: A total of 224 providers completed the survey. The majority of respondents were general dentists with more than 20 years in practice, who practice in a private setting, and see more than 10 patients in a day. All respondents stated they perform intraoral examinations, but 10 respondents stated they do not perform extraoral examinations. Nearly a third of respondents reported doing their own biopsies. CONCLUSIONS: Although only 8.5% of oral healthcare providers in Virginia responded to our survey, respondents are following the 2017 ADA good practice statement by providing their patients with head and neck exams to screen for oral cancer. Additional education pertaining to extraoral anatomy, malignant transformation of oral potentially malignant disorders, and pathology procedures may be helpful to clinicians.


Assuntos
Doenças da Boca , Neoplasias Bucais , Humanos , Estudos Transversais , Neoplasias Bucais/diagnóstico , Encaminhamento e Consulta , Odontólogos
11.
J Phycol ; 59(6): 1133-1146, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37548118

RESUMO

The Klebsormidiophyceae are a class of green microalgae observed globally in both freshwater and terrestrial habitats. Morphology-based classification schemes of this class have been shown to be inadequate due to the simple morphology of these algae, the tendency of morphology to vary in culture versus field conditions, and rampant morphological homoplasy. Molecular studies revealing cryptic diversity have renewed interest in this group. We sequenced the complete chloroplast genomes of a broad series of taxa spanning the known taxonomic breadth of this class. We also sequenced the chloroplast genomes of three strains of Streptofilum, a recently discovered green algal lineage with close affinity to the Klebsormidiophyceae. Our results affirm the previously hypothesized polyphyly of the genus Klebsormidium as well as the polyphyly of the nominal species in this genus, K. flaccidum. Furthermore, plastome sequences strongly support the status of Streptofilum as a distinct, early-diverging lineage of charophytic algae sister to a clade comprising Klebsormidiophyceae plus Phragmoplastophyta. We also uncovered major structural alterations in the chloroplast genomes of species in Klebsormidium that have broad implications regarding the underlying mechanisms of chloroplast genome evolution.


Assuntos
Clorófitas , Genoma de Cloroplastos , Filogenia , Clorófitas/genética , Evolução Molecular
12.
Arch Biochem Biophys ; 743: 109669, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37356607

RESUMO

Cytochrome P450 (P450, CYP) 27C1 is expressed in human skin and catalyzes the 3,4-desaturation of retinoids. The enzyme has a relatively high specificity constant (kcat/Km), and ∼» of the retinoids in human skin are in the desaturated form but their function is unknown. 3,4-Dehydroretinoic acid (also didehydroretinoic acid, ddRA) has similar affinity as all-trans retinoic acid (atRA) for retinoid X and retinoic acid receptors (RXRs/RAR). The metabolism of ddRA is unknown, and we considered the hypothesis that desaturation might be a protective mechanism in maintaining active retinoid levels in the body. There are limited theoretical products that can result from ddRA oxidation. We optimized conditions for oxidation of atRA by human liver microsomes-a slow loss of atRA was seen due to 4-oxidation but no loss of ddRA was observed under the same conditions. We evaluated the HPLC peaks that were observed in microsomal incubations with ddRA using UV spectroscopy, NaBH4 and NaBD4 reduction, and mass spectrometry. None were potential ddRA oxidation products, and none were increased in the presence of the P450 cofactor NADPH. Known P450 inhibitors had no effects on the levels of these compounds. We conclude that ddRA is not readily oxidized by P450s and that one role of desaturation may be the maintenance of levels of functional retinoids.


Assuntos
Retinoides , Tretinoína , Humanos , Tretinoína/metabolismo , Retinoides/metabolismo , Retinoides/farmacologia , Receptores do Ácido Retinoico/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Microssomos Hepáticos/metabolismo
14.
Drug Metab Rev ; 54(3): 318-330, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35876105

RESUMO

The 24th North American International Society for the Study of Xenobiotics (ISSX) meeting, held virtually from September 13 to 17, 2021, embraced the theme of "Broadening Our Horizons." This reinforces a key mission of ISSX: striving to share innovative science related to drug discovery and development. Session speakers and the ISSX New Investigators Group, which supports the scientific and professional development of student and early career ISSX members, elected to highlight the scientific content presented during the captivating session titled, "Epigenetics in Drug Disposition & Drug Therapy." The impact genetic variation has on drug response is well established; however, this session underscored the importance of investigating the role of epigenetics in drug disposition and drug discovery. Session speakers, Drs. Ning, McClay, and Lazarus, detailed mechanisms by which epigenetic players including long non-coding RNA (lncRNAs), microRNA (miRNAs), DNA methylation, and histone acetylation can alter the expression of genes involved in pharmacokinetics, pharmacodynamics, and toxicity. Dr. Ning detailed current knowledge about miRNAs and lncRNAs and the mechanisms by which they can affect the expression of drug metabolizing enzymes (DMEs) and nuclear receptors. Dr. Lazarus discussed the potential role of miRNAs on UDP-glucuronosyltransferase (UGT) expression and activity. Dr. McClay provided evidence that aging alters methylation and acetylation of DMEs in the liver, affecting gene expression and activity. These topics, compiled by the symposium organizers, presenters, and the ISSX New Investigators Group, are herein discussed, along with exciting future perspectives for epigenetics in drug disposition and drug discovery research.


Assuntos
Descoberta de Drogas , Epigênese Genética , MicroRNAs , RNA Longo não Codificante , Metilação de DNA , Humanos , MicroRNAs/genética , América do Norte , RNA Longo não Codificante/genética
15.
Membranes (Basel) ; 12(6)2022 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-35736284

RESUMO

Ion adsorbing ultrafiltration membranes provide an interesting possibility to remove toxic ions from water. Furthermore, it is also possible to recover valuable elements. In this work, we demonstrate two easy strategies to modify polyacrylonitrile membranes with anion and cation adsorbing groups. The membranes were modified to have positively charged amine groups or negatively charged carboxyl groups. The success of the reactions was confirmed using IR spectroscopy and zeta-potential measurements. The membranes carrying negatively charged groups provided a negative zeta-potential and had an isoelectric point at pH 3.6, while the membranes carrying positively charged groups had a positive zeta-potential in the analyzed pH range. Since only the surface of the polymer was modified, the pore size and permeance of the membranes were not drastically affected. The membranes prepared by both modification strategies had a pure water permeance higher than 1000 L/(m2 h bar) and a water contact angle of 44.3 and 57.2°, respectively. Therefore, the membranes can be operated at low pressures with reasonable flux. Additionally, SEM images showed that the membranes were still open-pored. Adsorption tests using a positively and a negatively charged dye as well as a toxic cation and an anion were performed to analyze the adsorption behavior. Both membranes were able to adsorb the oppositely charged dyes as well as the copper and chromate ions. Therefore, these membranes are good candidates to purify water streams containing hazardous ions.

16.
Gastroenterology ; 163(5): 1188-1197, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35724732

RESUMO

There has been significant progress in the study of extracellular vesicles (EVs) since the 2017 American Gastroenterological Association-sponsored Freston Conference "Extracellular Vesicles: Biology, Translation and Clinical Application in GI Disorders." The burgeoning interest in this field stems from the increasing recognition that EVs represent an understudied form of cell-to-cell communication and contain cargo replete with biomarkers and therapeutic targets. This short review will highlight recent advances in the field, with an emphasis on colorectal cancer. After a brief introduction to secreted particles, we will describe how our laboratory became interested in EVs, which led to refined methods of isolation and identification of 2 secreted nanoparticles. We will then summarize the cargo found in small EVs released from colorectal cancer cells and other cells in the tumor microenvironment, as well as those found in the circulation of patients with colorectal cancer. Finally, we will consider the continuing challenges and future opportunities in this rapidly evolving field.


Assuntos
Neoplasias Colorretais , Vesículas Extracelulares , Neoplasias , Humanos , Microambiente Tumoral , Biomarcadores , Neoplasias Colorretais/terapia , Neoplasias/terapia
17.
Microorganisms ; 10(5)2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35630304

RESUMO

Porphyrinoid-based photodynamic inactivation (PDI) provides a promising approach to treating multidrug-resistant infections. However, available agents for PDI still have optimization potential with regard to effectiveness, toxicology, chemical stability, and solubility. The currently available photosensitizer TMPyP is provided with a para substitution pattern (para-TMPyP) of the pyridinium groups and has been demonstrated to be effective for PDI of multidrug-resistant bacteria. To further improve its properties, we synthetized a structural variant of TMPyP with an isomeric substitution pattern in a meta configuration (meta-TMPyP), confirmed the correct structure by crystallographic analysis and performed a characterization with NMR-, UV/Vis-, and IR spectroscopy, photostability, and singlet oxygen generation assay. Meta-TMPyP had a hypochromic shift in absorbance (4 nm) with a 55% higher extinction coefficient and slightly improved photostability (+6.9%) compared to para-TMPyP. Despite these superior molecular properties, singlet oxygen generation was increased by only 5.4%. In contrast, PDI, based on meta-TMPyP, reduced the density of extended spectrum ß-lactamase-producing and fluoroquinolone-resistant Escherichia coli by several orders of magnitude, whereby a sterilizing effect was observed after 48 min of illumination, while para-TMPyP was less effective (p < 0.01). These findings demonstrate that structural modification with meta substitution increases antibacterial properties of TMPyP in PDI.

18.
Microorganisms ; 10(5)2022 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-35630394

RESUMO

Antimicrobial resistance belongs to the most demanding medical challenges, and antimicrobial photodynamic inactivation (aPDI) is considered a promising alternative to classical antibiotics. However, the pharmacologic characterization of novel compounds suitable for aPDI is a tedious and time-consuming task that usually requires preparation of bacterial cultures and counting of bacterial colonies. In this study, we established and utilized a luminescence-based microbial cell viability assay to analyze the aPDI effects of two porphyrin-based photosensitizers (TMPyP and THPTS) on several bacterial strains with antimicrobial resistance. We demonstrate that after adaptation of the protocol and initial calibration to every specific bacterial strain and photosensitizer, the luminometric method can be used to reliably quantify aPDI effects in most of the analyzed bacterial strains. The interference of photosensitizers with the luminometric readout and the bioluminescence of some bacterial strains were identified as possible confounders. Using this method, we could confirm the susceptibility of several bacterial strains to photodynamic treatment, including extensively drug-resistant pathogens (XDR). In contrast to the conventional culture-based determination of bacterial density, the luminometric assay allowed for a much more time-effective analysis of various treatment conditions. We recommend this luminometric method for high-throughput tasks requiring measurements of bacterial viability in the context of photodynamic treatment approaches.

19.
Mol Cancer ; 21(1): 74, 2022 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-35279145

RESUMO

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) is a process linked to metastasis and drug resistance with non-coding RNAs (ncRNAs) playing pivotal roles. We previously showed that miR-100 and miR-125b, embedded within the third intron of the ncRNA host gene MIR100HG, confer resistance to cetuximab, an anti-epidermal growth factor receptor (EGFR) monoclonal antibody, in colorectal cancer (CRC). However, whether the MIR100HG transcript itself has a role in cetuximab resistance or EMT is unknown. METHODS: The correlation between MIR100HG and EMT was analyzed by curating public CRC data repositories. The biological roles of MIR100HG in EMT, metastasis and cetuximab resistance in CRC were determined both in vitro and in vivo. The expression patterns of MIR100HG, hnRNPA2B1 and TCF7L2 in CRC specimens from patients who progressed on cetuximab and patients with metastatic disease were analyzed by RNAscope and immunohistochemical staining. RESULTS: The expression of MIR100HG was strongly correlated with EMT markers and acted as a positive regulator of EMT. MIR100HG sustained cetuximab resistance and facilitated invasion and metastasis in CRC cells both in vitro and in vivo. hnRNPA2B1 was identified as a binding partner of MIR100HG. Mechanistically, MIR100HG maintained mRNA stability of TCF7L2, a major transcriptional coactivator of the Wnt/ß-catenin signaling, by interacting with hnRNPA2B1. hnRNPA2B1 recognized the N6-methyladenosine (m6A) site of TCF7L2 mRNA in the presence of MIR100HG. TCF7L2, in turn, activated MIR100HG transcription, forming a feed forward regulatory loop. The MIR100HG/hnRNPA2B1/TCF7L2 axis was augmented in specimens from CRC patients who either developed local or distant metastasis or had disease progression that was associated with cetuximab resistance. CONCLUSIONS: MIR100HG and hnRNPA2B1 interact to control the transcriptional activity of Wnt signaling in CRC via regulation of TCF7L2 mRNA stability. Our findings identified MIR100HG as a potent EMT inducer in CRC that may contribute to cetuximab resistance and metastasis by activation of a MIR100HG/hnRNPA2B1/TCF7L2 feedback loop.


Assuntos
Neoplasias Colorretais , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B , MicroRNAs , RNA Longo não Codificante , Linhagem Celular Tumoral , Movimento Celular/genética , Cetuximab/genética , Cetuximab/metabolismo , Neoplasias Colorretais/patologia , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Ribonucleoproteínas Nucleares Heterogêneas Grupo A-B/genética , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética , Proteína 2 Semelhante ao Fator 7 de Transcrição/metabolismo , Via de Sinalização Wnt/genética
20.
J Clin Invest ; 132(6)2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35289315

RESUMO

De novo and acquired resistance are major impediments to the efficacy of conventional and targeted cancer therapy. In unselected gastric cancer (GC) patients with advanced disease, trials combining chemotherapy and an anti-EGFR monoclonal antibody have been largely unsuccessful. In an effort to identify biomarkers of resistance so as to better select patients for such trials, we screened the secretome of chemotherapy-treated human GC cell lines. We found that levels of CGA, the α-subunit of glycoprotein hormones, were markedly increased in the conditioned media of chemoresistant GC cells, and CGA immunoreactivity was enhanced in GC tissues that progressed on chemotherapy. CGA levels in plasma increased in GC patients who received chemotherapy, and this increase was correlated with reduced responsiveness to chemotherapy and poor survival. Mechanistically, secreted CGA was found to bind to EGFR and activate EGFR signaling, thereby conferring a survival advantage to GC cells. N-glycosylation of CGA at Asn52 and Asn78 is required for its stability, secretion, and interaction with EGFR. GATA2 was found to activate CGA transcription, whose increase, in turn, induced the expression and phosphorylation of GATA2 in an EGFR-dependent manner, forming a positive feedback circuit that was initiated by GATA2 autoregulation upon sublethal exposure to chemotherapy. Based on this circuit, combination strategies involving anti-EGFR therapies or targeting CGA with microRNAs (miR-708-3p and miR-761) restored chemotherapy sensitivity. These findings identify a clinically actionable CGA/EGFR/GATA2 circuit and highlight CGA as a predictive biomarker and therapeutic target in chemoresistant GC.


Assuntos
MicroRNAs , Neoplasias Gástricas , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Receptores ErbB/genética , Receptores ErbB/metabolismo , Retroalimentação , Fator de Transcrição GATA2/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo
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