RESUMO
In this perspective I look back on the twists and turns that influenced the direction of my scientific career over the past 40 years. From my early ambition to be a chemist to my training in Philadelphia and Bethesda as a molecular biologist, I benefited enormously from generous and valuable mentoring. In my independent career in Philadelphia and Princeton, I was motivated by a keen interest in the changes in gene expression that direct the development of the mammalian embryo and inspired by the creativity and energy of my students, fellows, and research staff. After twelve years as President of Princeton University, I have happily returned to the faculty of the Department of Molecular Biology.
Assuntos
Biologia Molecular/história , Universidades/história , Sequência de Aminoácidos , Animais , Canadá , Passeio de Cromossomo , Desenvolvimento Embrionário/genética , Proteínas do Olho/genética , Proteínas do Olho/história , Regulação da Expressão Gênica no Desenvolvimento , Impressão Genômica , História do Século XX , História do Século XXI , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/história , Humanos , Camundongos , Dados de Sequência Molecular , National Institutes of Health (U.S.) , New Jersey , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/história , Splicing de RNA , RNA Longo não Codificante/genética , RNA Longo não Codificante/história , Proteínas Repressoras/genética , Proteínas Repressoras/história , Estados Unidos , alfa-Fetoproteínas/genética , alfa-Fetoproteínas/história , Globinas beta/genética , Globinas beta/históriaRESUMO
Secreted signals, known as morphogens, provide the positional information that organizes gene expression and cellular differentiation in many developing tissues. In the vertebrate neural tube, Sonic Hedgehog (Shh) acts as a morphogen to control the pattern of neuronal subtype specification. Using an in vivo reporter of Shh signaling, mouse genetics, and systems modeling, we show that a spatially and temporally changing gradient of Shh signaling is interpreted by the regulatory logic of a downstream transcriptional network. The design of the network, which links three transcription factors to Shh signaling, is responsible for differential spatial and temporal gene expression. In addition, the network renders cells insensitive to fluctuations in signaling and confers hysteresis--memory of the signal. Our findings reveal that morphogen interpretation is an emergent property of the architecture of a transcriptional network that provides robustness and reliability to tissue patterning.
Assuntos
Redes Reguladoras de Genes , Proteínas Hedgehog/metabolismo , Tubo Neural/metabolismo , Transdução de Sinais , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas do Olho/genética , Proteínas Hedgehog/genética , Proteína Homeobox Nkx-2.2 , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Camundongos , Camundongos Transgênicos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/metabolismo , Fator de Transcrição 2 de Oligodendrócitos , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/genética , Proteínas Repressoras/genética , Fatores de Transcrição/metabolismo , Proteínas de Peixe-Zebra , Proteína Gli3 com Dedos de ZincoRESUMO
During development, neural stem cells in the cerebral cortex, also known as radial glial cells (RGCs), generate excitatory neurons, followed by production of cortical macroglia and inhibitory neurons that migrate to the olfactory bulb (OB). Understanding the mechanisms for this lineage switch is fundamental for unraveling how proper numbers of diverse neuronal and glial cell types are controlled. We and others recently showed that Sonic Hedgehog (Shh) signaling promotes the cortical RGC lineage switch to generate cortical oligodendrocytes and OB interneurons. During this process, cortical RGCs generate intermediate progenitor cells that express critical gliogenesis genes Ascl1, Egfr, and Olig2. The increased Ascl1 expression and appearance of Egfr+ and Olig2+ cortical progenitors are concurrent with the switch from excitatory neurogenesis to gliogenesis and OB interneuron neurogenesis in the cortex. While Shh signaling promotes Olig2 expression in the developing spinal cord, the exact mechanism for this transcriptional regulation is not known. Furthermore, the transcriptional regulation of Olig2 and Egfr has not been explored. Here, we show that in cortical progenitor cells, multiple regulatory programs, including Pax6 and Gli3, prevent precocious expression of Olig2, a gene essential for production of cortical oligodendrocytes and astrocytes. We identify multiple enhancers that control Olig2 expression in cortical progenitors and show that the mechanisms for regulating Olig2 expression are conserved between the mouse and human. Our study reveals evolutionarily conserved regulatory logic controlling the lineage switch of cortical neural stem cells.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Córtex Cerebral , Receptores ErbB , Proteínas Hedgehog , Proteínas do Tecido Nervoso , Células-Tronco Neurais , Neurogênese , Fator de Transcrição 2 de Oligodendrócitos , Fator de Transcrição PAX6 , Animais , Neurogênese/fisiologia , Córtex Cerebral/metabolismo , Córtex Cerebral/citologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Receptores ErbB/metabolismo , Receptores ErbB/genética , Camundongos , Fator de Transcrição 2 de Oligodendrócitos/metabolismo , Fator de Transcrição 2 de Oligodendrócitos/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas Hedgehog/metabolismo , Proteínas Hedgehog/genética , Fator de Transcrição PAX6/metabolismo , Fator de Transcrição PAX6/genética , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/genética , Proteína Gli3 com Dedos de Zinco/metabolismo , Proteína Gli3 com Dedos de Zinco/genética , Proteínas do Olho/metabolismo , Proteínas do Olho/genética , Proteínas Repressoras/metabolismo , Proteínas Repressoras/genética , Fatores de Transcrição Box Pareados/metabolismo , Fatores de Transcrição Box Pareados/genética , Neuroglia/metabolismo , Neuroglia/citologia , Regulação da Expressão Gênica no Desenvolvimento , Transdução de Sinais , Bulbo Olfatório/metabolismo , Bulbo Olfatório/citologia , Linhagem da Célula , HumanosRESUMO
The development of stable specialized cell types in multicellular organisms relies on mechanisms controlling inductive intercellular signals and the competence of cells to respond to such signals. In developing cerebral cortex, progenitors generate only glutamatergic excitatory neurons despite being exposed to signals with the potential to initiate the production of other neuronal types, suggesting that their competence is limited. Here, we tested the hypothesis that this limitation is due to their expression of transcription factor Pax6. We used bulk and single-cell RNAseq to show that conditional cortex-specific Pax6 deletion from the onset of cortical neurogenesis allowed some progenitors to generate abnormal lineages resembling those normally found outside the cortex. Analysis of selected gene expression showed that the changes occurred in specific spatiotemporal patterns. We then compared the responses of control and Pax6-deleted cortical cells to in vivo and in vitro manipulations of extracellular signals. We found that Pax6 loss increased cortical progenitors' competence to generate inappropriate lineages in response to extracellular factors normally present in developing cortex, including the morphogens Shh and Bmp4. Regional variation in the levels of these factors could explain spatiotemporal patterns of fate change following Pax6 deletion in vivo. We propose that Pax6's main role in developing cortical cells is to minimize the risk of their development being derailed by the potential side effects of morphogens engaged contemporaneously in other essential functions.
Assuntos
Proteínas de Homeodomínio , Fatores de Transcrição Box Pareados , Córtex Cerebral/metabolismo , Proteínas do Olho/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/metabolismo , Fator de Transcrição PAX6/genética , Fator de Transcrição PAX6/metabolismo , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Proteínas Repressoras/metabolismoRESUMO
The hallmarks of the alveolar subclass of rhabdomyosarcoma are chromosomal translocations that generate chimeric PAX3-FOXO1 or PAX7-FOXO1 transcription factors. Overexpression of either PAX-FOXO1s results in related cell transformation in animal models. Yet, in patients the two structural genetic aberrations they derived from are associated with distinct pathological manifestations. To assess the mechanisms underlying these differences, we generated isogenic fibroblast lines expressing either PAX-FOXO1 paralog. Mapping of their genomic recruitment using CUT&Tag revealed that the two chimeric proteins have distinct DNA binding preferences. In addition, PAX7-FOXO1 binding results in greater recruitment of the H3K27ac activation mark than PAX3-FOXO1 binding and is accompanied by greater transcriptional activation of neighbouring genes. These effects are associated with a PAX-FOXO1-specific alteration in the expression of genes regulating cell shape and the cell cycle. Consistently, PAX3-FOXO1 accentuates fibroblast cellular traits associated with contractility and surface adhesion and limits entry into S phase. In contrast, PAX7-FOXO1 drives cells to adopt an amoeboid shape, reduces entry into M phase, and causes increased DNA damage. Altogether, our results argue that the diversity of rhabdomyosarcoma manifestation arises, in part, from the divergence between the genomic occupancy and transcriptional activity of PAX3-FOXO1 and PAX7-FOXO1.
Assuntos
Proteínas de Fusão Oncogênica , Fatores de Transcrição Box Pareados , Rabdomiossarcoma Alveolar , Animais , Linhagem Celular , Transformação Celular Neoplásica/genética , Fibroblastos , Proteína Forkhead Box O1/genética , Fatores de Transcrição Forkhead/genética , Humanos , Proteínas de Fusão Oncogênica/genética , Fator de Transcrição PAX3/genética , Fator de Transcrição PAX7/genética , Fatores de Transcrição Box Pareados/genética , Rabdomiossarcoma/genética , Rabdomiossarcoma Alveolar/genéticaRESUMO
The role extracellular matrix (ECM) in multiple events of morphogenesis has been well described, little is known about its specific role in early eye development. One of the first morphogenic events in lens development is placodal thickening, which converts the presumptive lens ectoderm from cuboidal to pseudostratified epithelium. This process occurs in the anterior pre-placodal ectoderm when the optic vesicle approaches the cephalic ectoderm and is regulated by transcription factor Pax6 and secreted BMP4. Since cells and ECM have a dynamic relationship of interdependence and modulation, we hypothesized that the ECM evolves with cell shape changes during lens placode formation. This study investigates changes in optic ECM including both protein distribution deposition, extracellular gelatinase activity and gene expression patterns during early optic development using chicken and mouse models. In particular, the expression of Timp2, a metalloprotease inhibitor, corresponds with a decrease in gelatinase activity within the optic ECM. Furthermore, we demonstrate that optic ECM remodeling depends on BMP signaling in the placode. Together, our findings suggest that the lens placode plays an active role in remodeling the optic ECM during early eye development.
Assuntos
Matriz Extracelular , Regulação da Expressão Gênica no Desenvolvimento , Cristalino , Fator de Transcrição PAX6 , Animais , Matriz Extracelular/metabolismo , Camundongos , Cristalino/metabolismo , Cristalino/crescimento & desenvolvimento , Cristalino/citologia , Fator de Transcrição PAX6/metabolismo , Fator de Transcrição PAX6/genética , Proteínas do Olho/metabolismo , Proteínas do Olho/genética , Proteína Morfogenética Óssea 4/metabolismo , Proteína Morfogenética Óssea 4/genética , Embrião de Galinha , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/genética , Inibidor Tecidual de Metaloproteinase-2/metabolismo , Inibidor Tecidual de Metaloproteinase-2/genética , Fatores de Transcrição Box Pareados/metabolismo , Fatores de Transcrição Box Pareados/genética , Proteínas Repressoras/metabolismo , Proteínas Repressoras/genética , Transdução de Sinais , Galinhas/genética , Olho/metabolismo , Olho/crescimento & desenvolvimento , Olho/embriologiaRESUMO
Development of the Xenopus pronephros relies on renal precursors grouped at neurula stage into a specific region of dorso-lateral mesoderm called the kidney field. Formation of the kidney field at early neurula stage is dependent on retinoic (RA) signaling acting upstream of renal master transcriptional regulators such as pax8 or lhx1. Although lhx1 might be a direct target of RA-mediated transcriptional activation in the kidney field, how RA controls the emergence of the kidney field remains poorly understood. In order to better understand RA control of renal specification of the kidney field, we have performed a transcriptomic profiling of genes affected by RA disruption in lateral mesoderm explants isolated prior to the emergence of the kidney field and cultured at different time points until early neurula stage. Besides genes directly involved in pronephric development (pax8, lhx1, osr2, mecom), hox (hoxa1, a3, b3, b4, c5 and d1) and the hox co-factor meis3 appear as a prominent group of genes encoding transcription factors (TFs) downstream of RA. Supporting the idea of a role of meis3 in the kidney field, we have observed that meis3 depletion results in a severe inhibition of pax8 expression in the kidney field. Meis3 depletion only marginally affects expression of lhx1 and aldh1a2 suggesting that meis3 principally acts upstream of pax8. Further arguing for a role of meis3 and hox in the control of pax8, expression of a combination of meis3, hoxb4 and pbx1 in animal caps induces pax8 expression, but not that of lhx1. The same combination of TFs is also able to transactivate a previously identified pax8 enhancer, Pax8-CNS1. Mutagenesis of potential PBX-Hox binding motifs present in Pax8-CNS1 further allows to identify two of them that are necessary for transactivation. Finally, we have tested deletions of regulatory sequences in reporter assays with a previously characterized transgene encompassing 36.5 âkb of the X. tropicalis pax8 gene that allows expression of a truncated pax8-GFP fusion protein recapitulating endogenous pax8 expression. This transgene includes three conserved pax8 enhancers, Pax8-CNS1, Pax8-CNS2 and Pax8-CNS3. Deletion of Pax8-CNS1 alone does not affect reporter expression, but deletion of a 3.5 âkb region encompassing Pax8-CNS1 and Pax8-CNS2 results in a severe inhibition of reporter expression both in the otic placode and kidney field domains.
Assuntos
Pronefro , Tretinoína , Animais , Xenopus laevis/genética , Xenopus laevis/metabolismo , Tretinoína/farmacologia , Tretinoína/metabolismo , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Pronefro/metabolismo , Rim/metabolismo , Família Aldeído Desidrogenase 1 , Retinal Desidrogenase/metabolismoRESUMO
We dissect genetically a gene regulatory network that involves the transcription factors Tbx4, Pitx1 and Isl1 acting cooperatively to establish the hindlimb bud, and identify key differences in the pathways that initiate formation of the hindlimb and forelimb. Using live image analysis of murine limb mesenchyme cells undergoing chondrogenesis in micromass culture, we distinguish a series of changes in cellular behaviours and cohesiveness that are required for chondrogenic precursors to undergo differentiation. Furthermore, we provide evidence that the proximal hindlimb defects observed in Tbx4 mutant mice result from a failure in the early differentiation step of chondroprogenitors into chondrocytes, providing an explanation for the origins of proximally biased limb defects.
Assuntos
Membro Posterior/anormalidades , Botões de Extremidades/metabolismo , Proteínas com Domínio T/metabolismo , Animais , Células Cultivadas , Condrócitos/citologia , Condrócitos/metabolismo , Condrogênese , Proteínas com Homeodomínio LIM/genética , Proteínas com Homeodomínio LIM/metabolismo , Botões de Extremidades/citologia , Botões de Extremidades/crescimento & desenvolvimento , Células-Tronco Mesenquimais/metabolismo , Camundongos , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Proteínas com Domínio T/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Although aberrant methylation of PAX1 is closely associated with cervical cancer (CC), PAX1 methylation (PAX1m) and its role in CC remain to be elucidated. Here, we clarified the biological function of PAX1 in CC. First, PAX1m in ThinPrep cytologic test samples was measured via quantitative methylation-specific PCR. The results showed that PAX1 promoter methylation levels were significantly increased in CC patients (p < 0.001). We also found that PAX1 promoter methylation levels were positively correlated with tumor purity but negatively correlated with immune-infiltration via public databases. Then, CRISPR-based methylation perturbation tools (dCas9-Tet1) were constructed to further demonstrate that DNA methylation participates in the regulation of PAX1 expression directly. Gain- and loss-of-function experiments were used to show that PAX1 overexpression restrained proliferation, migration and improved cisplatin sensitivity by interfering with the WNT/TIMELESS axis in CC cells. Additionally, Co-immunoprecipitation assays further confirmed the interaction between PAX1 and TCF7L2. Taken together, our results suggested that a tumor suppressor role of PAX1 in CC and that CRISPR-based PAX1 demethylation editing might be a promising therapeutic strategy for CC.
Assuntos
Proliferação de Células , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Neoplasias do Colo do Útero , Via de Sinalização Wnt , Feminino , Humanos , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/genética , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Regiões Promotoras Genéticas , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/metabolismo , Via de Sinalização Wnt/genéticaRESUMO
Methylation panels, tools for investigating epigenetic changes associated with diseases like cancer, can identify DNA methylation patterns indicative of disease, providing diagnostic or prognostic insights. However, the application of methylation panels focusing on the sex-determining region Y-box 1 (SOX1) and paired box gene 1 (PAX1) genes for diagnosing cervical lesions is under-researched. This study aims to examine the diagnostic performance of PAX1/SOX1 gene methylation as a marker for cervical precancerous lesions and its potential application in triage diagnosis. From September 2022 to April 2023, 181 patients with abnormal HPV-DNA tests or cytological exam results requiring colposcopy were studied at Hubei Maternal and Child Health Hospital, China. Data were collected from colposcopy, cytology, HPV-DNA tests, and PAX1/SOX1 methylation detection. Patients were categorized as control, cervical intraepithelial neoplasia Grade 1 (CIN1), Grade 2 (CIN2), Grade 3 (CIN3), and cervical cancer (CC) groups based on histopathology. We performed HPV testing, liquid-based cytology, and PAX1/SOX1 gene methylation testing. We evaluated the diagnostic value of methylation detection in cervical cancer using DNA methylation positivity rate, sensitivity, specificity, and area under the curve (AUC), and explored its potential for triage diagnosis. PAX1/SOX1 methylation positivity rates were: control 17.1%, CIN1 22.5%, CIN2 100.0%, CIN3 90.0%, and CC 100.0%. The AUC values for PAX1 gene methylation detection in diagnosing CIN1+, CIN2+, and CIN3+ were 0.52 (95% confidence interval [CI]: 0.43-0.62), 0.88 (95% CI: 0.80-0.97), and 0.88 (95% CI: 0.75-1.00), respectively. Corresponding AUC values for SOX1 gene methylation detection were 0.47 (95% CI: 0.40-0.58), 0.80 (95% CI: 0.68-0.93), and 0.92 (95% CI: 0.811-1.00), respectively. In HPV16/18-negative patients, methylation detection showed sensitivity of 32.4% and specificity of 83.7% for CIN1+. For CIN2+ and CIN3+, sensitivity was all 100%, with specificities of 83.0% and 81.1%. Among the patients who underwent colposcopy examination, 166 cases had cytological examination results ≤ASCUS, of which 37 cases were positive for methylation, and the colposcopy referral rate was 22.29%. PAX1/SOX1 gene methylation detection exhibits strong diagnostic efficacy for cervical precancerous lesions and holds significant value in triage diagnosis.
Assuntos
Metilação de DNA , Fatores de Transcrição Box Pareados , Infecções por Papillomavirus , Fatores de Transcrição SOXB1 , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Adulto Jovem , Biomarcadores Tumorais/genética , China , Colposcopia , Detecção Precoce de Câncer/métodos , Fatores de Transcrição Box Pareados/genética , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/virologia , Infecções por Papillomavirus/genética , Lesões Pré-Cancerosas/diagnóstico , Lesões Pré-Cancerosas/genética , Sensibilidade e Especificidade , Fatores de Transcrição SOXB1/genética , Triagem/métodos , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/genética , Displasia do Colo do Útero/virologia , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/genéticaRESUMO
Paired box (Pax) genes are highly conserved throughout evolution, and the Pax protein is an important transcription factor of embryonic development. The Pax gene Bmgsb is expressed in the silk glands of silkworm, but its biological functions remain unclear. This study aimed to investigate the expression pattern of Bmgsb in the silk gland and explore its functions using RNA interference (RNAi). Here, we identified eight Pax genes in Bombyx mori. Phylogenetic analysis showed that the B. mori Pax genes were highly homologous to the Pax genes in other insects and highly evolutionarily conserved. The tissue expression profile showed that Bmgsb was expressed in the anterior silk gland and anterior part of the middle silk gland (AMSG). RNAi of Bmgsb resulted in defective development of the AMSG, and the larvae were mostly unable to cocoon in the wandering stage. RNA-seq analysis showed that the fibroin genes fib-l, fib-h and p25, cellular heat shock response-related genes and phenol oxidase genes were considerably upregulated upon Bmgsb knockdown. Furthermore, quantitative reverse transcription-PCR results showed that the fibroin genes and ubiquitin proteolytic enzyme-related genes were significantly upregulated in the AMSG after Bmgsb knockdown. This study provides a foundation for future research on the biological functions of B. mori Pax genes. In addition, it demonstrates the important roles of Bmgsb in the transcriptional regulation of fibroin genes and silk gland development.
Assuntos
Bombyx , Proteínas de Insetos , Fatores de Transcrição Box Pareados , Animais , Bombyx/classificação , Bombyx/genética , Bombyx/crescimento & desenvolvimento , Bombyx/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Larva/crescimento & desenvolvimento , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Filogenia , Interferência de RNA , Seda/genética , Seda/metabolismoRESUMO
BACKGROUND: In China, the national cervical cancer screening protocol involves initial testing for high-risk human papillomavirus (hrHPV), followed by cytology for hrHPV-positive cases. This study evaluates the effectiveness of PAX1 methylation (PAX1m) analysis in identifying precancerous or cancerous lesions in cervical samples from Chinese women positive for non-16/18 hrHPV strains. METHODS: Between February 2022 and March 2023, 281 cervical samples from non-16/18 hrHPV-positive women underwent cytological examination and PAX1m analysis. The study assessed the statistical relationship between PAX1m levels and the presence of cervical lesions, comparing the diagnostic performance of PAX1m to conventional cytology. RESULTS: A significant association was found between PAX1 methylation levels and the risk of CIN2 + and CIN3 + lesions, with 47 instances of CIN2 + detected. Odds ratios (ORs) for moderate and high PAX1m levels were 8.86 (95% CI: 2.24-42.17) and 166.32 (95% CI: 47.09-784.97), respectively. The area under the ROC curve for PAX1m in identifying CIN2 + lesions was 0.948 (95% CI: 0.895-0.99). PAX1m demonstrated similar sensitivity and negative predictive value (NPV) to cytology but reduced the colposcopy referral rate from 47.7% with cytology alone to 25.6% with PAX1m, showing superior specificity and positive predictive value across age groups. CONCLUSIONS: PAX1 methylation is a strong indicator of CIN2 + and CIN3 + risk, offering diagnostic performance comparable to cytology with the added benefit of reduced unnecessary colposcopy referrals. These findings support the use of PAX1m analysis as a reliable tool for triaging non-16/18 hrHPV-positive women in outpatient settings.
Assuntos
Metilação de DNA , Detecção Precoce de Câncer , Fatores de Transcrição Box Pareados , Infecções por Papillomavirus , Triagem , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/virologia , Neoplasias do Colo do Útero/genética , Pessoa de Meia-Idade , Detecção Precoce de Câncer/métodos , Adulto , Fatores de Transcrição Box Pareados/genética , Infecções por Papillomavirus/virologia , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/genética , Triagem/métodos , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/virologia , Displasia do Colo do Útero/genética , China/epidemiologia , Idoso , Curva ROC , Biomarcadores Tumorais/genética , Esfregaço VaginalRESUMO
Aniridia is a panocular condition characterized by a partial or complete loss of the iris. It manifests various developmental deficits in both the anterior and posterior segments of the eye, leading to a progressive vision loss. The homeobox gene PAX6 plays an important role in ocular development and mutations of PAX6 have been the main causative factors for aniridia. In this study, we assessed how Pax6-haploinsufficiency affects retinal morphology and vision of Pax6Sey mice using in vivo and ex vivo metrics. We used mice of C57BL/6 and 129S1/Svlmj genetic backgrounds to examine the variable severity of symptoms as reflected in human aniridia patients. Elevated intraocular pressure (IOP) was observed in Pax6Sey mice starting from post-natal day 20 (P20). Correspondingly, visual acuity showed a steady age-dependent decline in Pax6Sey mice, though these phenotypes were less severe in the 129S1/Svlmj mice. Local retinal damage with layer disorganization was assessed at P30 and P80 in the Pax6Sey mice. Interestingly, we also observed a greater number of activated Iba1+ microglia and GFAP + astrocytes in the Pax6Sey mice than in littermate controls, suggesting a possible neuroinflammatory response to Pax6 deficiencies.
Assuntos
Aniridia , Microftalmia , Humanos , Camundongos , Animais , Fator de Transcrição PAX6/genética , Fatores de Transcrição Box Pareados/genética , Doenças Neuroinflamatórias , Camundongos Endogâmicos C57BL , Microftalmia/genética , Aniridia/genética , Proteínas de Homeodomínio/genética , Proteínas do Olho/genéticaRESUMO
Heterozygous mutation of PAX6 in humans leads to congenital aniridia (OMIM 106210) which is typified by congenital iris and foveal defects, and later onset glaucoma, aniridic keratopathy, and cataract. Mice heterozygous for Pax6 mutations phenocopy many aspects of aniridia including the iris defects, keratopathy and cataract, although Pax6 mutant mice have small lenses, a phenotype which is not typically reported in human aniridia, perhaps due to difficulties in measuring lens diameter during typical ophthalmic examinations as the lens periphery is shielded by the iris. In order to overcome this, records of patients diagnosed with congenital aniridia between April 2015 and May 2021 at the Necker-Enfants Malades Hospital, and genetically confirmed with a disease-causing PAX6 variant, were retrospectively reviewed for those with normal axial length whose iris defects allowed visualization of the lens margins and corneal diameter to allow calculation of a lens/corneal diameter ratio. This value was compared with values obtained from a cohort of patients with Sjödell grade IV oculocutaneous albinism type 1 (OCA1; OMIM 203100) which allowed visualization of the lens periphery via iris transillumination. This analysis revealed that patients with congenital aniridia had a significantly lower lens/corneal ratio when compared to those with albinism, suggesting that humans haploinsufficient for PAX6, like mice, rats, frogs, and zebrafish, exhibit reductions in lens size.
Assuntos
Aniridia , Catarata , Doenças da Córnea , Humanos , Camundongos , Ratos , Animais , Fator de Transcrição PAX6/genética , Fatores de Transcrição Box Pareados/genética , Estudos Retrospectivos , Peixe-Zebra , Aniridia/genética , Aniridia/diagnóstico , Mutação , Catarata/genética , Catarata/congênito , Proteínas de Homeodomínio/genética , Proteínas do Olho/genéticaRESUMO
BACKGROUND: Haploinsufficiency of the transcription factor PAX6 is the main cause of congenital aniridia, a genetic disorder characterized by iris and foveal hypoplasia. 11p13 microdeletions altering PAX6 or its downstream regulatory region (DRR) are present in about 25% of patients; however, only a few complex rearrangements have been described to date. Here, we performed nanopore-based whole-genome sequencing to assess the presence of cryptic structural variants (SVs) on the only two unsolved "PAX6-negative" cases from a cohort of 110 patients with congenital aniridia after unsuccessfully short-read sequencing approaches. RESULTS: Long-read sequencing (LRS) unveiled balanced chromosomal rearrangements affecting the PAX6 locus at 11p13 in these two patients and allowed nucleotide-level breakpoint analysis. First, we identified a cryptic 4.9 Mb de novo inversion disrupting intron 7 of PAX6, further verified by targeted polymerase chain reaction amplification and sequencing and FISH-based cytogenetic analysis. Furthermore, LRS was decisive in correctly mapping a t(6;11) balanced translocation cytogenetically detected in a second proband with congenital aniridia and considered non-causal 15 years ago. LRS resolved that the breakpoint on chromosome 11 was indeed located at 11p13, disrupting the DNase I hypersensitive site 2 enhancer within the DRR of PAX6, 161 Kb from the causal gene. Patient-derived RNA expression analysis demonstrated PAX6 haploinsufficiency, thus supporting that the 11p13 breakpoint led to a positional effect by cleaving crucial enhancers for PAX6 transactivation. LRS analysis was also critical for mapping the exact breakpoint on chromosome 6 to the highly repetitive centromeric region at 6p11.1. CONCLUSIONS: In both cases, the LRS-based identified SVs have been deemed the hidden pathogenic cause of congenital aniridia. Our study underscores the limitations of traditional short-read sequencing in uncovering pathogenic SVs affecting low-complexity regions of the genome and the value of LRS in providing insight into hidden sources of variation in rare genetic diseases.
Assuntos
Aniridia , Fatores de Transcrição Box Pareados , Humanos , Fatores de Transcrição Box Pareados/genética , Proteínas de Homeodomínio/genética , Proteínas Repressoras/genética , Aniridia/genética , Inversão Cromossômica , MutaçãoRESUMO
BACKGROUND: Paired box 1 (PAX1) is a transcription factor and essential for the development of pharyngeal pouches-derived tissues, including thymus. PAX1 mutations are identified in Severe Combined Immunodeficiency (SCID) patients with Otofaciocervical Syndrome Type 2 (OTFCS2). However, despite the critical roles of PAX1 in embryonic development and diseases, detailed insights into its molecular mode of action are critically missing. METHODS: The repressing roles of PAX1 and SCID associated mutants on Wnt signaling pathway were investigated by luciferase reporter assays, qRT-PCR and in situ hybridization in HEK293FT, HCT116 cells and zebrafish embryos, respectively. Co-immunoprecipitation (co-IP) and western blotting assays were carried out to identify the molecular mechanisms underlying PAX1's role on Wnt signaling pathway. hESC based endoderm differentiation, flow cytometry, high-throughput sequencing data analysis, and qRT-PCR assays were utilized to determine the roles of PAX1 during endoderm differentiation. RESULTS: Here, we show that PAX1 represses canonical Wnt signaling pathway in vertebrate cells. Mechanically, PAX1 competes with SUMO E3 ligase PIASy to bind to TCF7L2, thus perturbing TCF7L2 SUMOylation level, further reducing its transcriptional activity and protein stability. Moreover, we reveal that PAX1 plays dual roles in hESC-derived definitive and foregut/pharyngeal endoderm cells, which give rise to the thymus epithelium, by inhibiting Wnt signaling. Importantly, our data show PAX1 mutations found in SCID patients significantly compromise the suppressing ability of PAX1 on Wnt signaling. CONCLUSIONS: Our study presents a novel molecular mode of action of PAX1 in regulation of canonical Wnt signaling and endoderm differentiation, thus providing insights for the molecular basis of PAX1 associated SCID, offering better understanding of the behavior of PAX1 in embryogenesis.
Assuntos
Diferenciação Celular , Endoderma , Via de Sinalização Wnt , Peixe-Zebra , Humanos , Via de Sinalização Wnt/genética , Diferenciação Celular/genética , Endoderma/metabolismo , Endoderma/citologia , Animais , Peixe-Zebra/genética , Células HEK293 , Proteína 2 Semelhante ao Fator 7 de Transcrição/metabolismo , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética , Células HCT116 , Fatores de Transcrição Box Pareados/metabolismo , Fatores de Transcrição Box Pareados/genéticaRESUMO
BACKGROUND: Diabetes is a chronic metabolic disease that affects many parts of the body. Considering diabetes as a beta cells' defect and loss, the focus is on finding mechanisms and compounds involved in stimulating the function and regeneration of pancreatic ß-cells. DNA methylation as an epigenetic mechanism plays a pivotal role in the ß-cells' function and development. Considering the regenerative and anti-diabetic effects of Rosa canina extract, this study aimed to assess the methylation levels of Pdx-1, Pax-4, and Ins-1 genes in diabetic rats treated with Rosa Canina extract. METHODS AND RESULTS: Streptozotocin-induced diabetic rats were used to evaluate the frequency of Pdx-1, Pax-4, and Ins-1 gene methylation. Treatment groups were exposed to Rosa canina as spray-dried and decoction extracts. Following blood glucose measurement, pancreatic DNA was extracted and bisulfited. Genes' methylation was measured using MSP-PCR and qRT-PCR techniques. Oral administration of Rosa canina extracts significantly reduced blood sugar levels in diabetic rats compared to the control group. The methylation levels of the Pdx-1, Pax-4, and Ins-1 genes promoter in streptozotocin-induced diabetic rats increased compared to the control rats while, the treatment of diabetic rats with Rosa canina extracts, spray-dried samples especially, led to a decreased methylation in these genes. CONCLUSION: The results of this study showed that Rosa canina extract as a spray-dried sample could be effective in treating diabetes by regulating the methylation of genes including Pdx-1, Pax-4, and Ins-1 involved in the activity and regeneration of pancreatic islet cells.
Assuntos
Glicemia , Metilação de DNA , Diabetes Mellitus Experimental , Extratos Vegetais , Rosa , Transativadores , Animais , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/tratamento farmacológico , Rosa/química , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/genética , Ratos , Extratos Vegetais/farmacologia , Masculino , Transativadores/genética , Transativadores/metabolismo , Glicemia/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Pâncreas/patologia , Estreptozocina , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Insulina/metabolismoRESUMO
Alveolar rhabdomyosarcoma (ARMS), an invasive subtype of rhabdomyosarcoma (RMS), is associated with chromosomal translocation events resulting in one of two oncogenic fusion genes, PAX3-FOXO1 or PAX7-FOXO1. ARMS patients exhibit an overexpression of the pleiotropic cytokine transforming growth factor beta (TGF-ß). This overexpression of TGF-ß1 causes an increased expression of a downstream transcription factor called SNAIL, which promotes epithelial to mesenchymal transition (EMT). Overexpression of TGF-ß also inhibits myogenic differentiation, making ARMS patients highly resistant to chemotherapy. In this review, we first describe different types of RMS and then focus on ARMS and the impact of TGF-ß in this tumor type. We next highlight current chemotherapy strategies, including a combination of the FDA-approved drugs vincristine, actinomycin D, and cyclophosphamide (VAC); cabozantinib; bortezomib; vinorelbine; AZD 1775; and cisplatin. Lastly, we discuss chemotherapy agents that target the differentiation of tumor cells in ARMS, which include all-trans retinoic acid (ATRA) and 5-Azacytidine. Improving our understanding of the role of signaling pathways, such as TGF-ß1, in the development of ARMS tumor cells differentiation will help inform more tailored drug administration in the future.
Assuntos
Rabdomiossarcoma Alveolar , Rabdomiossarcoma , Humanos , Rabdomiossarcoma Alveolar/genética , Rabdomiossarcoma Alveolar/metabolismo , Rabdomiossarcoma Alveolar/patologia , Fator de Crescimento Transformador beta , Fator de Crescimento Transformador beta1 , Fatores de Transcrição Box Pareados/genética , Transição Epitelial-Mesenquimal , Rabdomiossarcoma/genética , Proteínas de Fusão Oncogênica/genéticaRESUMO
Renal cell carcinoma (RCC) is a significant oncological challenge due to its heterogeneous nature and limited treatment options. The PAX developmental gene family encodes nine highly conserved transcription factors that play crucial roles in embryonic development and organogenesis, which have been implicated in the occurrence and development of RCC. This review explores the molecular landscape of RCC, with a specific focus on the role of the PAX gene family in RCC tumorigenesis and disease progression. Of the various RCC subtypes, clear cell renal cell carcinoma (ccRCC) is the most prevalent, characterized by the loss of the von Hippel-Lindau (VHL) tumor suppressor gene. Here, we review the published literature on the expression patterns and functional implications of PAX genes, particularly PAX2 and PAX8, in the three most common RCC subtypes, including ccRCC, papillary RCC (PRCC), and chromophobe RCC (ChRCC). Further, we review the interactions and potential biological mechanisms involving PAX genes and VHL loss in driving the pathogenesis of RCC, including the key signaling pathways mediated by VHL in ccRCC and associated mechanisms implicating PAX. Lastly, concurrent with our update regarding PAX gene research in RCC, we review and comment on the targeting of PAX towards the development of novel RCC therapies.
Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Fatores de Transcrição Box Pareados , Humanos , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Regulação Neoplásica da Expressão Gênica , Fator de Transcrição PAX2/genética , Fator de Transcrição PAX2/metabolismo , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo , Animais , Fator de Transcrição PAX8/genética , Fator de Transcrição PAX8/metabolismo , Transdução de Sinais/genéticaRESUMO
Objective: To explore the value of cervical cytologic DNA methylation for screening cervical cancer. Methods: This study was a prospective multicenter study conducted from May to October 2022 in Peking Union Medical College Hospital, Zhejiang Provincial People's Hospital, and the Second Affiliated Hospital of Zhejiang University School of Medicine. Women who accepted opportunistic cervical cancer screening in gynecological outpatient clinics were subjected to liquid-based thin-layer cytology testing (TCT), high-risk human papillomavirus (hrHPV) DNA testing and PAX1/JAM3 dual-genes methylation testing (PAX1m/JAM3m). Colposcopy evaluation and biopsy were offered to women according to current guidelines. The accuracies of various testing methods and their combinations were compared based on histological diagnosis. Results: A total of 1 184 samples diagnosed by histopathology were included in this study, consisting of 541 cases (45.7%) of benign cervical tissue or chronic cervicitis, 273 (23.1%) of cervical intraepithelial neoplasia (CIN) 1, 168 (14.2%) of CIN2, 140 (11.8%) of CIN3, and 62 (5.2%) of cervical cancer. The sensitivity and specificity of PAX1m/JAM3m testing for detecting CIN2 or more severe lesions (CIN2+) were 74.1% and 95.9%, respectively. The sensitivity and specificity of PAX1m/JAM3m testing for detecting CIN3+were 87.6% and 86.8%, respectively. Receiver operating characteristic curve analysis showed that, for detecting CIN3+, the area under curve of PAX1m/JAM3m testing (0.872, 95%CI: 0.847-0.897) was significantly superior to TCT testing (0.580, 95%CI: 0.551-0.610) or hrHPV testing (0.503, 95%CI: 0.479-0.515) (all P values<0.05). Conclusions: The PAX1m/JAM3m test in cervical exfoliated cells has excellent accuracy for the diagnosis of both CIN2+and CIN3+, which is superior to traditional screening protocols and screening strategies.