RESUMEN
The E-protein transcription factors guide immune cell differentiation, with E12 and E47 (hereafter called E2A) being essential for B-cell specification and maturation. E2A and the oncogenic chimera E2A-PBX1 contain three transactivation domains (ADs), with AD1 and AD2 having redundant, independent, and cooperative functions in a cell-dependent manner. AD1 and AD2 both mediate their functions by binding to the KIX domain of the histone acetyltransferase paralogues CREB-binding protein (CBP) and E1A-binding protein P300 (p300). This interaction is necessary for B-cell maturation and oncogenesis by E2A-PBX1 and occurs through conserved ΦXXΦΦ motifs (with Φ denoting a hydrophobic amino acid) in AD1 and AD2. However, disruption of this interaction via mutation of the KIX domain in CBP/p300 does not completely abrogate binding of E2A and E2A-PBX1. Here, we determined that E2A-AD1 and E2A-AD2 also interact with the TAZ2 domain of CBP/p300. Characterization of the TAZ2:E2A-AD1(1-37) complex indicated that E2A-AD1 adopts an α-helical structure and uses its ΦXXΦΦ motif to bind TAZ2. Whereas this region overlapped with the KIX recognition region, key KIX-interacting E2A-AD1 residues were exposed, suggesting that E2A-AD1 could simultaneously bind both the KIX and TAZ2 domains. However, we did not detect a ternary complex involving E2A-AD1, KIX, and TAZ2 and found that E2A containing both intact AD1 and AD2 is required to bind to CBP/p300. Our findings highlight the structural plasticity and promiscuity of E2A-AD1 and suggest that E2A binds both the TAZ2 and KIX domains of CBP/p300 through AD1 and AD2.
Asunto(s)
Proteína de Unión a CREB/química , Proteína p300 Asociada a E1A/genética , Dominios Proteicos/genética , Factor de Transcripción 3/química , Linfocitos B/química , Linfocitos B/metabolismo , Proteína de Unión a CREB/genética , Proteína de Unión a CREB/ultraestructura , Proteína p300 Asociada a E1A/química , Proteína p300 Asociada a E1A/ultraestructura , Proteínas de Homeodominio/química , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/ultraestructura , Humanos , Mutación/genética , Proteínas de Fusión Oncogénica/química , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/ultraestructura , Unión Proteica/genética , Conformación Proteica , Factor de Transcripción 3/genética , Factor de Transcripción 3/ultraestructuraRESUMEN
BACKGROUND: Under the National Comprehensive Cancer Network (NCCN) guidelines for non-small-cell lung carcinoma (NSCLC), anaplastic lymphoma kinase (ALK) gene rearrangement is required to be assessed. However, data showing the prevalence of the ALK rearrangement is still deficient and is not yet available in Indonesia. This study used direct smear preparation from transthoracic needle specimens that are minimally invasive. The main objective of the study is to identify the prevalence of the ALK fusion rearrangement gene in cytological specimens. MATERIALS AND METHODS: A total of 35 direct smear preparations diagnosed as lung adenocarcinoma and EGFR mutation negative were involved in this study. The samples were taken between 2017 and 2019. These samples were examined for EML4-ALK fusion rearrangement gene using qRT-PCR. The EML4-ALK rearrangement status was determined by qRT-PCR with high-resolution melting (HRM) analysis. RESULTS: A total of 28 (80%) samples were from males, and 7 samples were from females. Seven (20% 95% CI: 8.4%-36.9%) samples were EML4-ALK rearrangement positive. The average age of the patients was 63.5 years old. The most common sites of metastasis in this study were pleural cavity, bone, liver, and CNS. CONCLUSIONS: qRT-PCR successfully identified EML4-ALK fusion rearrangement in direct smear preparations of lung adenocarcinoma. Direct smear samples can be used for EML4-ALK rearrangement detection using qRT-PCR. The EML4-ALK rearrangement gene has high prevalence in selected lung adenocarcinoma and EGFR mutation-negative populations. ALK inhibitors in lung cancer can be openly considered for use in Indonesian patients to improve the outcome of this subset of patients.
Asunto(s)
Adenocarcinoma del Pulmón/genética , Neoplasias Pulmonares/genética , Proteínas de Fusión Oncogénica/genética , Adenocarcinoma del Pulmón/ultraestructura , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Femenino , Humanos , Indonesia , Pulmón/ultraestructura , Neoplasias Pulmonares/ultraestructura , Masculino , Persona de Mediana Edad , Proteínas de Fusión Oncogénica/ultraestructura , PrevalenciaRESUMEN
ProMyelocyticLeukemia (PML) protein can polymerize into a mega-Dalton nuclear assembly of 0.1-2 µm in diameter. The mechanism of PML nuclear body biogenesis remains elusive. Here, PMLRBCC is successfully purified. The gel filtration and ultracentrifugation analysis suggest a previously unrecognized sequential oligomerization mechanism via PML monomer, dimer, tetramer and N-mer. Consistently, PML B1-box structure (2.0 Å) and SAXS characterization reveal an unexpected networking by W157-, F158- and SD1-interfaces. Structure-based perturbations in these B1 interfaces not only impair oligomerization in vitro but also abolish PML sumoylation and nuclear body biogenesis in HeLaPml-/- cell. More importantly, as demonstrated by in vivo study using transgenic mice, PML-RARα (PR) F158E precludes leukemogenesis. In addition, single cell RNA sequencing analysis shows that B1 oligomerization is an important regulator in PML-RARα-driven transactivation. Altogether, these results not only define a previously unrecognized B1-box oligomerization in PML, but also highlight oligomerization as an important factor in carcinogenesis.
Asunto(s)
Carcinogénesis , Leucemia Promielocítica Aguda/patología , Proteína de la Leucemia Promielocítica/metabolismo , Multimerización de Proteína , Animales , Técnicas de Inactivación de Genes , Células HeLa , Humanos , Leucemia Promielocítica Aguda/genética , Ratones , Ratones Transgénicos , Mutación , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/metabolismo , Proteínas de Fusión Oncogénica/ultraestructura , Proteína de la Leucemia Promielocítica/genética , Proteína de la Leucemia Promielocítica/ultraestructura , Dominios Proteicos/genética , Receptor alfa de Ácido Retinoico/genética , Receptor alfa de Ácido Retinoico/metabolismo , Receptor alfa de Ácido Retinoico/ultraestructura , Dispersión del Ángulo Pequeño , Análisis de Secuencia de ARN , Análisis de la Célula Individual , Sumoilación , Difracción de Rayos XRESUMEN
This is a case report of a 46-year-old white male who presented with dyspnea. Thoracic and abdominal examinations showed a heterogeneously enhancing mass in the right kidney, multiple pulmonary nodules, and left pleural thickening with large pleural effusion. Pleura biopsy revealed a malignant neoplasm composed of cells with predominantly clear cytoplasm. Considering the large mass in the right kidney, clear cell renal cell carcinoma (RCC) was the main differential diagnosis. The diagnosis in this case was not definitive by histology alone since clear cell RCC markers such as RCC and AE1/AE3 were negative, and CD10 was only focally positive. Transcription factor E3 (TFE3) immunohistochemistry was positive, while the XP11.2 translocation testing was negative. Electron microscopy demonstrated that the tumor cells had abundant cytoplasmic glycogen and lipid, focal long microvilli lining rare lumina, and adjacent interdigitating cell membranes joining the neoplastic cells, indicating a diagnosis of renal clear cell carcinoma. In addition, numerous crystalline-like dense granules were identified in the cytoplasm of the neoplastic cells, which are reminiscent of those typically seen in alveolar soft part sarcoma and rarely described in XP11.2 translocation RCC. Overall, this renal tumor likely represents a variant of XP11.2 translocation RCC, overexpressing TFE3 with dense granules.
