Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 110
Filtrar
1.
EMBO J ; 40(22): e107485, 2021 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-34605568

RESUMEN

Although large exons cannot be readily recognized by the spliceosome, many are evolutionarily conserved and constitutively spliced for inclusion in the processed transcript. Furthermore, whether large exons may be enriched in a certain subset of proteins, or mediate specific functions, has remained unclear. Here, we identify a set of nearly 3,000 SRSF3-dependent large constitutive exons (S3-LCEs) in human and mouse cells. These exons are enriched for cytidine-rich sequence motifs, which bind and recruit the splicing factors hnRNP K and SRSF3. We find that hnRNP K suppresses S3-LCE splicing, an effect that is mitigated by SRSF3 to thus achieve constitutive splicing of S3-LCEs. S3-LCEs are enriched in genes for components of transcription machineries, including mediator and BAF complexes, and frequently contain intrinsically disordered regions (IDRs). In a subset of analyzed S3-LCE-containing transcription factors, SRSF3 depletion leads to deletion of the IDRs due to S3-LCE exon skipping, thereby disrupting phase-separated assemblies of these factors. Cytidine enrichment in large exons introduces proline/serine codon bias in intrinsically disordered regions and appears to have been evolutionarily acquired in vertebrates. We propose that layered splicing regulation by hnRNP K and SRSF3 ensures proper phase-separation of these S3-LCE-containing transcription factors in vertebrates.


Asunto(s)
Exones , Factores de Empalme Serina-Arginina/genética , Factores de Transcripción/genética , Vertebrados/genética , Animales , Línea Celular , Citidina/genética , Evolución Molecular , Ribonucleoproteína Heterogénea-Nuclear Grupo K/genética , Ribonucleoproteína Heterogénea-Nuclear Grupo K/metabolismo , Humanos , Proteínas Intrínsecamente Desordenadas/genética , Proteínas Intrínsecamente Desordenadas/metabolismo , Ratones , Poliadenilación , Empalme del ARN , Proteínas de Unión al ARN/genética , Factores de Empalme Serina-Arginina/metabolismo , Factores de Transcripción/metabolismo
2.
Cell Struct Funct ; 2024 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-39384365

RESUMEN

The sarcomere is the contractile unit of striated muscle and is composed of actin and myosin filaments. There is increasing evidence to support that actin assembly mediated by Fhod3, a member of the formin family of proteins, is critical for sarcomere formation and maintenance in cardiac muscle. Fhod3, which is abundantly expressed in the heart, localizes to the center of sarcomeres and contributes to the regulation of the cardiac function, as evidenced by the fact that mutations in Fhod3 cause cardiomyopathy. However, the role of Fhod3 in skeletal muscle, another type of striated muscle, is unclear. We herein show that Fhod3 is expressed in the tongue at both mRNA and protein levels, although in smaller amounts than in the heart. To determine the physiological role of Fhod3 expressed in the tongue, we generated embryos lacking Fhod3 in the tongue. The tongue tissue of the Fhod3-depleted embryos did not show any significant structural defects, suggesting that Fhod3 is dispensable for normal development of the mouse tongue. Unexpectedly, the immunostaining analysis revealed the absence of specific sarcomeric signals for Fhod3 in the wild-type tongue when compared to the Fhod3-depleted tongue as a negative control, despite the use of antibodies that had previously been validated by immunostaining of heart tissues. Taken together, although Fhod3 protein is expressed at a significant level in the tongue, Fhod3 in the tongue does not appear to exhibit the same sarcomeric pattern as observed in the heart, suggesting a different role for Fhod3 in the tongue muscles.Key words: actin, formin, sarcomere, striated muscle.

3.
Exp Cell Res ; 410(2): 112969, 2022 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-34883111

RESUMEN

MEL1 (MDS1/EVI1-like gene 1/PRDM16), a zinc finger protein, is located near the chromosomal breakpoint at 1p36 in human acute myeloid leukemia (AML) cells with the t (1; 3) (p36; q21) translocation. Mel1/Prdm16 is not only a causative gene of leukemia, but also has multiple regulatory functions, such as the regulation of fat metabolism. To investigate the function of Mel1/Prdm16, we generated Mel1/Prdm16-deficient mice, but homozygous deficiency (Mel1/Prdm16-/-) was embryonic lethal at E 11.5. Heterozygous mice showed abnormal cartilage and bone formation in the postnatal skull and long bones, suggesting that Mel1/Prdm16 expression plays an important role in bone development. In osteoblast and chondrocyte cell lines, Mel1/Prdm16 promotes the differentiation of chondrocytes and regulates the differentiation of osteoblasts. Transient repression of the master regulator Runx2 is required for chondrocyte differentiation at an early stage of differentiation. However, in Mel1/Prdm16-suppressed ATDC5 cells, the initial suppression of Runx2 was lacking and its expression was upregulated at the beginning of differentiation, suggesting that chondrogenic differentiation is suppressed in Mel1/Prdm16+/- mesenchymal progenitor cells because Runx2 expression is upregulated during the early stage of differentiation. Thus, the Mel1/Prdm16 gene may be involved in the early repression of Runx2 expression during osteochondral differentiation and promote chondrogenic differentiation.


Asunto(s)
Huesos/anatomía & histología , Huesos/citología , Diferenciación Celular , Proteínas de Unión al ADN/metabolismo , Factores de Transcripción/metabolismo , Animales , Secuencia de Bases , Proteína Morfogenética Ósea 2/metabolismo , Cartílago/patología , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Proteínas de Unión al ADN/deficiencia , Proteínas de Homeodominio/metabolismo , Ratones , Ratones Noqueados , Modelos Biológicos , Osteoblastos/citología , Osteoblastos/metabolismo , Osteogénesis , Transducción de Señal , Factores de Transcripción/deficiencia
4.
Cancer Sci ; 113(6): 2179-2193, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35332604

RESUMEN

Hepatocyte growth factor (HGF) activator inhibitor type-1 (HAI-1), encoded by the SPINT1 gene, is a transmembrane protease inhibitor that regulates membrane-anchored serine proteases, particularly matriptase. Here, we explored the role of HAI-1 in tongue squamous cell carcinoma (TSCC) cells. An immunohistochemical study of HAI-1 in surgically resected TSCC revealed the cell surface immunoreactivity of HAI-1 in the main portion of the tumor. The immunoreactivity decreased in the infiltrative front, and this decrease correlated with enhanced lymphatic invasion as judged by podoplanin immunostaining. In vitro homozygous deletion of SPINT1 (HAI-1KO) in TSCC cell lines (HSC3 and SAS) suppressed the cell growth rate but significantly enhanced invasion in vitro. The loss of HAI-1 resulted in enhanced pericellular activities of proteases, such as matriptase and urokinase-type plasminogen activator, which induced activation of HGF/MET signaling in the co-culture with pro-HGF-expressing fibroblasts and plasminogen-dependent plasmin generation, respectively. The enhanced plasminogen-dependent plasmin generation was abrogated partly by matriptase silencing. Culture supernatants of HAI-1KO cells had enhanced potency for converting the proform of vascular endothelial growth factor-C (VEGF-C), a lymphangiogenesis factor, into the mature form in a plasminogen-dependent manner. Furthermore, HGF significantly stimulated VEGF-C expression in TSCC cells. Orthotopic xenotransplantation into nude mouse tongue revealed enhanced lymphatic invasion of HAI-1KO TSCC cells compared to control cells. Our results suggest that HAI-1 insufficiency leads to dysregulated pericellular protease activity, which eventually orchestrates robust activation of protease-dependent growth factors, such as HGF and VEGF-C, in a tumor microenvironment to contribute to TSCC progression.


Asunto(s)
Carcinoma de Células Escamosas , Proteínas Inhibidoras de Proteinasas Secretoras , Neoplasias de la Lengua , Animales , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Fibrinolisina/genética , Homocigoto , Humanos , Ratones , Plasminógeno/genética , Proteínas Inhibidoras de Proteinasas Secretoras/genética , Proteínas Inhibidoras de Proteinasas Secretoras/metabolismo , Eliminación de Secuencia , Serina Endopeptidasas , Neoplasias de la Lengua/genética , Neoplasias de la Lengua/patología , Microambiente Tumoral , Factor C de Crecimiento Endotelial Vascular/genética
5.
Histochem Cell Biol ; 157(3): 359-369, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35024954

RESUMEN

High-mobility group box 2 (HMGB2) is a chromatin-associated protein that is an important regulator of gene transcription, recombination, and repair processes. The functional importance of HMGB2 has been reported in various organs, including the testis, heart, and cartilage. However, its role in the ovary is largely unknown. In this study, ovary tissues from wild-type (WT) and HMGB2-knock-out (KO) mice were examined by histopathological staining and immunohistochemistry. The ovary size and weight were significantly lower in HMGB2-KO mice than in age-matched WT littermates. Histopathological analysis revealed ovarian atrophy and progressive fibrosis in 10-month-old HMGB2-KO mouse ovaries. Compared to age-matched WT mice, the numbers of oocytes and developing follicles were significantly decreased at 2 months of age and were completely depleted at 10 months of age in HMGB2-KO mice. Immunohistochemistry revealed the expression of HMGB2 in the granulosa cells of developing follicles, oocytes, some corpora lutea, and stromal cells. Importantly, HMGB2-positive cells were co-localized with estrogen receptor beta (ERß), but not ERα. Estrogen response element-binding activity was demonstrated by southwestern histochemistry, and it was decreased in HMGB2-KO mouse ovaries. Cell proliferation activity was also decreased in HMGB2-KO mouse ovaries in parallel with the decreased folliculogenesis. These results indicated that the depletion of HMGB2 induced ovarian atrophy that was characterized by a decreased ovarian size and weight, progressive fibrosis, as well as decreased oocytes and folliculogenesis. In conclusion, we demonstrated the crucial role of HMGB2 in mouse ovarian folliculogenesis through ERß expression.


Asunto(s)
Receptor beta de Estrógeno , Proteína HMGB2 , Animales , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/análisis , Receptor beta de Estrógeno/genética , Receptor beta de Estrógeno/metabolismo , Femenino , Células de la Granulosa , Proteína HMGB2/análisis , Proteína HMGB2/genética , Proteína HMGB2/metabolismo , Ratones , Ratones Noqueados , Ovario/metabolismo
6.
Int Immunol ; 32(10): 673-682, 2020 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-32415968

RESUMEN

C-type lectin receptors (CLRs), pattern recognition receptors (PRRs) with a characteristic carbohydrate recognition domain (CRD) in the extracellular portion, mediate crucial cellular functions upon recognition of glycosylated pathogens and self-glycoproteins. CLEC4A is the only classical CLR that possesses an intracellular immunoreceptor tyrosine-based inhibitory motif (ITIM), which possibly transduces negative signals. However, how CLEC4A exerts cellular inhibition remains unclear. Here, we report that the self-interaction of CLEC4A through the CRD is required for the ITIM-mediated suppressive function in conventional dendritic cells (cDCs). Human type 2 cDCs (cDC2) and monocytes display a higher expression of CLEC4A than cDC1 and plasmacytoid DCs (pDCs) as well as B cells. The extracellular portion of CLEC4A specifically binds to a murine cDC cell line expressing CLEC4A, while its extracellular portion lacking the N-glycosylation site or the EPS motif within the CRD reduces their association. Furthermore, the deletion of the EPS motif within the CRD or ITIM in CLEC4A almost completely impairs its suppressive effect on the activation of the murine cDC cell line, whereas the absence of the N-glycosylation site within the CRD exhibits partial inhibition on their activation. On the other hand, antagonistic monoclonal antibody (mAb) to CLEC4A, which inhibits the self-interaction of CLEC4A and its downstream signaling in murine transfectants, enhances the activation of monocytes and monocyte-derived immature DCs upon stimulation with a Toll-like receptor (TLR) ligand. Thus, our findings suggest a pivotal role of the CRD in self-interaction of CLEC4A to elicit the ITIM-mediated inhibitory signal for the control of the function of cDCs.


Asunto(s)
Carbohidratos/inmunología , Lectinas Tipo C/inmunología , Glicoproteínas de Membrana/inmunología , Receptores Inmunológicos/inmunología , Animales , Células Dendríticas/inmunología , Humanos , Motivo de Activación del Inmunorreceptor Basado en Tirosina/inmunología , Ratones , Ratones Endogámicos C57BL , Receptores de Reconocimiento de Patrones/inmunología
7.
PLoS Genet ; 13(6): e1006853, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28636652

RESUMEN

Triple-negative breast cancer (TNBC) cells do not express estrogen receptors, progesterone receptors, or human epidermal growth factor receptor 2. Currently, apart from poly ADP-ribose polymerase inhibitors, there are few effective therapeutic options for this type of cancer. Here, we present comprehensive characterization of the genetic alterations in TNBC performed by high coverage whole genome sequencing together with transcriptome and whole exome sequencing. Silencing of the BRCA1 gene impaired the homologous recombination pathway in a subset of TNBCs, which exhibited similar phenotypes to tumors with BRCA1 mutations; they harbored many structural variations (SVs) with relative enrichment for tandem duplication. Clonal analysis suggested that TP53 mutations and methylation of CpG dinucleotides in the BRCA1 promoter were early events of carcinogenesis. SVs were associated with driver oncogenic events such as amplification of MYC, NOTCH2, or NOTCH3 and affected tumor suppressor genes including RB1, PTEN, and KMT2C. Furthermore, we identified putative TGFA enhancer regions. Recurrent SVs that affected the TGFA enhancer region led to enhanced expression of the TGFA oncogene that encodes one of the high affinity ligands for epidermal growth factor receptor. We also identified a variety of oncogenes that could transform 3T3 mouse fibroblasts, suggesting that individual TNBC tumors may undergo a unique driver event that can be targetable. Thus, we revealed several features of TNBC with clinically important implications.


Asunto(s)
Proteína BRCA1/genética , Transcriptoma/genética , Neoplasias de la Mama Triple Negativas/genética , Proteína p53 Supresora de Tumor/genética , Células 3T3 , Animales , Metilación de ADN/genética , Exoma/genética , Femenino , Amplificación de Genes , Genoma Humano , Secuenciación de Nucleótidos de Alto Rendimiento , Recombinación Homóloga/genética , Humanos , Ratones , Mutación , Proteínas de Neoplasias/genética , Regiones Promotoras Genéticas , Neoplasias de la Mama Triple Negativas/patología
8.
Cancer Sci ; 110(9): 2973-2981, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31293054

RESUMEN

Every year, approximately 1.2 million cases of colorectal carcinoma (CRC) are newly diagnosed worldwide. Although metastases to distant organs are often fatal complications of CRC, little information is known as to how such metastatic lesions are formed. To reveal the genetic profiles for CRC metastasis, we conducted whole-exome RNA sequencing on CRC tumors with liver metastasis (LM) (group A, n = 12) and clinical stage-matched larger tumors without LM (group B, n = 16). While the somatic mutation profiles were similar among the primary tumors and LM lesions in group A and the tumors in group B, the A-to-C nucleotide change in the context of "AAG" was only enriched in the LM regions in group A, suggesting the presence of a DNA damage process specific to metastasis. Genes already known to be associated with CRC were mutated in all groups at a similar frequency, but we detected somatic nonsynonymous mutations in a total of 707 genes in the LM regions, but not in the tumors without LM. Signaling pathways linked to such "LM-associated" genes were overrepresented for extracellular matrix-receptor interaction or focal adhesion. Further, fusions of the ADAP1 (ArfGAP with dual PH domain 1) were newly identified in our cohort (3 out of 28 patients), which activated ARF6, an ADAP1-substrate. Infrequently, mutated genes may play an important role in metastasis formation of CRC. Additionally, recurrent ADAP1 fusion genes were unexpectedly discovered. As these fusions activate small GTPase, further experiments are warranted to examine their contribution to CRC carcinogenesis.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Neoplasias Colorrectales/genética , Fusión Génica , Neoplasias Hepáticas/genética , Proteínas del Tejido Nervioso/genética , Adulto , Anciano , Anciano de 80 o más Años , Carcinogénesis/genética , Neoplasias Colorrectales/patología , Análisis Mutacional de ADN , Femenino , Perfilación de la Expresión Génica , Células HEK293 , Humanos , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , Mutación Puntual , Secuenciación del Exoma
9.
Biochem Biophys Res Commun ; 509(1): 82-88, 2019 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-30587341

RESUMEN

We had previously reported that in addition to p53 inactivation, overexpression of the DNA sensor protein-absent in melanoma 2 (AIM2)-contributes to tumorigenesis of oral squamous cell carcinoma (OSCC). Given that AIM2 is highly expressed in the OSCC tumors from patients with metastasis, we investigated whether AIM2 expression contributes to the progression of OSCC metastasis. In in vitro assays using OSCC cell lines, the high migration and invasion capacity of OSCC cells were dependent on the increased expression of AIM2, resulting in enhanced epithelial-mesenchymal transition (EMT), with EMT-related gene expression. Moreover, the in vivo short-term metastasis assay using orthotopic implantation into immunodeficient mice demonstrated that OSCC cells with high levels of AIM2 expression exhibited enhanced tumor growth in the tongue, resulting in decreased survival of the mice. Further, the cells overexpressing AIM2 dominantly invaded into the tumor lymphatic vessels, unlike OSCC cells with low AIM2 expression. Thus, the high expression of AIM2 in OSCC enhances progression of tumor growth.


Asunto(s)
Carcinoma de Células Escamosas/genética , Proteínas de Unión al ADN/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias de la Boca/genética , Regulación hacia Arriba , Animales , Carcinoma de Células Escamosas/patología , Línea Celular Tumoral , Movimiento Celular , Progresión de la Enfermedad , Transición Epitelial-Mesenquimal , Femenino , Humanos , Ratones , Neoplasias de la Boca/patología , Invasividad Neoplásica/genética , Invasividad Neoplásica/patología , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patología , Neoplasias del Cuello Uterino/secundario
10.
Ann Surg Oncol ; 26(2): 555-563, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30515671

RESUMEN

BACKGROUND: This multicenter retrospective study aimed to determine whether elective neck dissection (END) can be performed for T1-2N0M0 tongue cancer. METHODS: Patients with T1-2N0M0 tongue squamous cell carcinoma who received treatment between January 2000 and December 2012 were enrolled at 14 multicenter study sites. The 5-year overall survival (OS) and 5-year disease-specific survival (DSS) were compared between the propensity score-matched END and observation (OBS) groups. RESULTS: The results showed that the OS rates among the 1234 enrolled patients were 85.5% in the END group and 90.2% in the OBS group (P = 0.182). The DSS rates were 87.0% in the END group and 94.3% in the OBS group (P = 0.003). Among the matched patients, the OS rates were 87.1% in the END group and 76.2% in the OBS group (P = 0.0051), and the respective DSS rates were 89.2% and 82.2% (P = 0.0335). CONCLUSION: This study showed that END is beneficial for T1-2N0M0 tongue cancer. However, END should be performed for patients with a tumor depth of 4-5 mm or more, which is the depth associated with a high rate of lymph node metastasis. The use of END should be carefully considered for both elderly and young patients.


Asunto(s)
Carcinoma de Células Escamosas/cirugía , Procedimientos Quirúrgicos Electivos/mortalidad , Disección del Cuello/mortalidad , Neoplasias de la Lengua/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/secundario , Femenino , Estudios de Seguimiento , Humanos , Metástasis Linfática , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Puntaje de Propensión , Estudios Retrospectivos , Tasa de Supervivencia , Neoplasias de la Lengua/patología , Adulto Joven
11.
Cancer Sci ; 108(9): 1888-1896, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28677170

RESUMEN

The major driver mutations of lung cancer, EGFR mutations and EML4-ALK fusion, are mainly detected in terminal respiratory unit (TRU)-type lung adenocarcinomas, which typically show lepidic and/or papillary patterns, but are rarely associated with a solid or invasive mucinous morphology. In order to elucidate the key genetic events in non-TRU-type lung cancer, we carried out whole-exome sequencing on 43 non-TRU-type lung adenocarcinomas based on morphology (17 acinar, nine solid, and two enteric adenocarcinomas, and 15 adenocarcinomas with a mucinous morphology). Our analysis identified mutations in TP53 (16/43, 37.2%), KRAS (13/43, 30.2%), and NKX2-1/TTF-1 (7/43; 16.3%) as the top three significantly mutated genes, while the EGFR mutation was rare (1/43, 2.3%) in this cohort. Eight NKX2-1/TTF-1 mutations (five frameshift, two nonsense, and one missense) were identified, with one case harboring two distinct NKX2-1/TTF-1 mutations (one missense and one frameshift). Functional assays with the NK2 homeobox 1 (NKX2-1)/thyroid transcription factor 1 (TTF-1) mutants revealed that none of them retain the activity as a transcriptional factor. Histologically, invasive mucinous adenocarcinomas accounted for most of the NKX2-1/TTF-1 mutations (five cases), as well as one enteric and one acinar adenocarcinoma. Immunohistochemistry showed that the cohort was largely divided into TTF-1-postive/hepatocyte nuclear factor 4-α (HNF4-α)-negative and TTF-1-negative/HNF4-α-positive groups. NKX2-1/TTF-1 mutations were exclusively found in the latter, in which the gastrointestinal markers, mucin 5AC and cytokeratin 20, were frequently expressed. Bisulfite sequencing revealed that the NKX2-1/TTF-1 gene body was highly methylated in NKX2-1/TTF-1-negative cases, including those without the NKX2-1/TTF-1 mutations. The genetic or epigenetic inactivation of NKX2-1/TTF-1 may play an essential role in the development and aberrant differentiation of non-TRU-type lung adenocarcinomas.


Asunto(s)
Adenocarcinoma/genética , Proteínas de Unión al ADN/genética , Neoplasias Pulmonares/genética , Proteínas Nucleares/genética , Factores de Transcripción/genética , Adenocarcinoma/patología , Línea Celular Tumoral , Metilación de ADN , Análisis Mutacional de ADN , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Células HEK293 , Humanos , Neoplasias Pulmonares/patología , Mutación , Factor Nuclear Tiroideo 1
12.
Proc Natl Acad Sci U S A ; 110(8): 3029-34, 2013 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-23382236

RESUMEN

Members of the RAS superfamily of small guanosine triphosphatases (GTPases) transition between GDP-bound, inactive and GTP-bound, active states and thereby function as binary switches in the regulation of various cellular activities. Whereas HRAS, NRAS, and KRAS frequently acquire transforming missense mutations in human cancer, little is known of the oncogenic roles of other small GTPases, including Ras-related C3 botulinum toxin substrate (RAC) proteins. We show that the human sarcoma cell line HT1080 harbors both NRAS(Q61K) and RAC1(N92I) mutant proteins. Whereas both of these mutants were able to transform fibroblasts, knockdown experiments indicated that RAC1(N92I) may be the essential growth driver for this cell line. Screening for RAC1, RAC2, or RAC3 mutations in cell lines and public databases identified several missense mutations for RAC1 and RAC2, with some of the mutant proteins, including RAC1(P29S), RAC1(C157Y), RAC2(P29L), and RAC2(P29Q), being found to be activated and transforming. P29S, N92I, and C157Y mutants of RAC1 were shown to exist preferentially in the GTP-bound state as a result of a rapid transition from the GDP-bound state, rather than as a result of a reduced intrinsic GTPase activity. Activating mutations of RAC GTPases were thus found in a wide variety of human cancers at a low frequency; however, given their marked transforming ability, the mutant proteins are potential targets for the development of new therapeutic agents.


Asunto(s)
GTP Fosfohidrolasas/metabolismo , Mutación , Neoplasias/enzimología , Proteínas de Unión al GTP rac/metabolismo , Línea Celular Tumoral , GTP Fosfohidrolasas/genética , Humanos , Modelos Moleculares , Proteínas de Unión al GTP rac/genética
13.
Cancer Sci ; 106(9): 1137-42, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26094954

RESUMEN

BIRC2 and BIRC3 are closely related members of the inhibitor of apoptosis (IAP) family of proteins and play pivotal roles in regulation of nuclear factor-κB (NF-κB) signaling and apoptosis. Copy number loss for and somatic mutation of BIRC2 and BIRC3 have been frequently detected in lymphoid malignancies, with such genetic alterations being thought to contribute to carcinogenesis through activation of the noncanonical NF-κB signaling pathway. Here we show that BIRC2 and BIRC3 mutations are also present in a wide range of epithelial tumors and that most such nonsense or frameshift mutations confer direct transforming potential. This oncogenic function of BIRC2/3 mutants is largely independent of their ability to activate NF-κB signaling. Rather, all of the transforming mutants lack an intact RING finger domain, with loss of ubiquitin ligase activity being essential for transformation irrespective of NF-κB regulation. The serine-threonine kinase NIK was found to be an important, but not exclusive, mediator of BIRC2/3-driven carcinogenesis, although this function was independent of NF-κB activation. Our data thus suggest that, in addition to the BIRC2/3-NIK-NF-κB signaling pathway, BIRC2/3-NIK signaling targets effectors other than NF-κB and thereby contributes directly to carcinogenesis. Identification of these effectors may provide a basis for the development of targeted agents for the treatment of lymphoid malignancies and other cancers with BIRC2/3 alterations.


Asunto(s)
Carcinogénesis/genética , Mutación del Sistema de Lectura/genética , Proteínas Inhibidoras de la Apoptosis/genética , FN-kappa B/genética , Ubiquitina-Proteína Ligasas/genética , Células 3T3 , Animales , Apoptosis/genética , Línea Celular , Células HEK293 , Humanos , Linfocitos/patología , Ratones , Proteínas Serina-Treonina Quinasas/genética , Dominios RING Finger/genética , Transducción de Señal/genética
14.
Neurobiol Dis ; 69: 200-5, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24878509

RESUMEN

Myotonic dystrophy type 1 (DM1) is caused by transcription of CUG repeat RNA, which causes sequestration of muscleblind-like 1 (MBNL1) and upregulation of CUG triplet repeat RNA-binding protein (CUG-BP1). In DM1, dysregulation of these proteins contributes to many aberrant splicing events, causing various symptoms of the disorder. Here, we demonstrate the occurrence of aberrant splicing of LIM domain binding 3 (LDB3) exon 11 in DM1 skeletal muscle. Exon array surveys, RT-PCR, and western blotting studies demonstrated that exon 11 inclusion was DM1 specific and could be reproduced by transfection of a minigene containing the CTG repeat expansion. Moreover, we found that the LDB3 exon 11-positive isoform had reduced affinity for PKC compared to the exon 11-negative isoform. Since PKC exhibits hyperactivation in DM1 and stabilizes CUG-BP1 by phosphorylation, aberrant splicing of LDB3 may contribute to CUG-BP1 upregulation through changes in its affinity for PKC.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas con Dominio LIM/genética , Proteínas con Dominio LIM/metabolismo , Músculo Esquelético/metabolismo , Distrofia Miotónica/genética , Distrofia Miotónica/metabolismo , Proteína Quinasa C/metabolismo , Adulto , Anciano , Niño , Estudios de Cohortes , Exones , Femenino , Humanos , Lactante , Isoenzimas , Masculino , Persona de Mediana Edad , Enfermedades Musculares/genética , Enfermedades Musculares/metabolismo , Isoformas de Proteínas , Empalme del ARN , Transfección , Expansión de Repetición de Trinucleótido , Adulto Joven
15.
Implant Dent ; 23(2): 108-15, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24637525

RESUMEN

There are numerous treatment modalities for mandibular defects after tumor surgery. Autogenous particulate cancellous bone marrow graft combined with titanium mesh (PCBM-MESH) is an alternative procedure. The purpose of this study was to evaluate PCBM-MESH for mandibular reconstruction. There were a total of 10 cases from 2000 to 2011. Mandibles were successfully reconstructed in 9 cases; however, reconstruction failed in 1 case. Overall, the recovery of facial contours was excellent; conversely, the evaluation of prosthetic treatment varied widely. Thus, we suggest 3 steps for mandibular reconstruction: (1) recover the continuity of bone segments; (2) simulate optimum facial contours and dental occlusion; and (3) perform the occlusion with dental prostheses. PCBM-MESH is a valuable method for mandibular defects-particularly for restoring facial contours and a favorable alveolar ridge.


Asunto(s)
Trasplante de Médula Ósea/métodos , Neoplasias Mandibulares/cirugía , Reconstrucción Mandibular/métodos , Mallas Quirúrgicas , Adulto , Anciano , Proceso Alveolar/cirugía , Femenino , Humanos , Masculino , Mandíbula/cirugía , Persona de Mediana Edad , Estudios Retrospectivos , Titanio
16.
Nanomaterials (Basel) ; 14(13)2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38998688

RESUMEN

The impact of oral administration of mechanically fibrillated cellulose nanofibers (fib-CNF), a commonly used nanofiber, on toxicity and health remains unclear, despite reports of the safety and beneficial effects of chitin-based nanofibers. Thus, evaluating the oral toxicity of fib-CNF in accordance with OECD Test Guideline 407 (TG407) is essential. This study aimed to assess the safety of orally administered fib-CNF through an acute toxicity study in rats, following the OECD TG407 guidelines for 4 weeks. CNF "BiNFi-s" FMa-10005, derived from mechanically fibrillated pulp cellulose, was administered via gavage to male and female Crl:CD(SD) rats at doses of 50, 150, 500, and 1000 mg/kg/day for 28 days, with a control group receiving water for injection. The study evaluated the toxic effects of repeated administration, and the rats were monitored for an additional 14 days post-administration to assess recovery from any toxic effects. The results showed no mortality in either sex during the administration period, and no toxicological effects related to the test substance were observed in various assessments, including general condition and behavioral function observations, urinalysis, hematological examination, blood biochemical examination, necropsy findings, organ weights, and histopathological examination. Notably, only female rats treated with 1000 mg/kg/day of CNF exhibited a consistent reduction in body weight during the 14-day recovery period after the end of treatment. They also showed a slight decrease in pituitary and liver weights. However, hematological and blood biochemical tests did not reveal significant differences, suggesting a potential weight-suppressive effect of CNF ingestion.

17.
J Stomatol Oral Maxillofac Surg ; 125(4S): 101907, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38714233

RESUMEN

INTRODUCTION: The extent of surgical resection for tongue tumors is determined by tumor size, potentially affecting oral function and quality of life (QoL). However, the relationship between oral dysfunction and QoL decline due to glossectomy extent remains unexplored. Therefore, these correlations and their predictive value for postoperative QoL decline were elucidated. METHODS: Patients treated for tongue cancer at our hospital between 2018 and 2022 were categorized by partial, hemi, or subtotal/total glossectomy. Assessments included swallowing function (RSST), articulation (Oral Diadochokinesis (ODK)), mastication, tongue pressure, and oral moisture. QoL was measured using the Oral Health Impact Profile-14 (OHIP-14). Differences within parameters were assessed using Kruskal-Wallis tests, and between-group comparisons via Mann-Whitney U tests. Spearman's correlation analysis examined parameter relationship. RESULTS: 35 patients were evaluated. Significant differences were found in ODK [ta] (p = 0.015), [ka] (p = 0.0006), tongue pressure (p = 0.0001), moisture levels (p = 0.031), OHIP-14 domains: physical disability (p = 0.014) and social disability (p = 0.046). ODK [ta] (PG: 5.95, HG: 5.38, TG: 4.03 times), [ka] (PG: 5.56, HG: 4.78, TG: 3.23 times), and tongue pressure (PG: 32.9, HG: 21.2, TG: 10.3 mmHg) decreased with glossectomy extent, while physical (PG: 0.27, HG: 2.38, TG: 2.00) and social disability (PG: 0.18, HG: 0.94, TG: 1.43) worsened. A significant negative correlation was observed between tongue pressure and social disability (p = 0.013, r = -0.36). CONCLUSION: Expanding resection significantly impacted postoperative oral function and QoL. Tongue pressure assessment may predict long-term social disability in patient QoL.


Asunto(s)
Glosectomía , Calidad de Vida , Neoplasias de la Lengua , Humanos , Neoplasias de la Lengua/cirugía , Neoplasias de la Lengua/patología , Masculino , Femenino , Persona de Mediana Edad , Anciano , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/psicología , Complicaciones Posoperatorias/etiología , Deglución/fisiología , Adulto , Lengua/cirugía , Lengua/fisiopatología , Anciano de 80 o más Años , Masticación/fisiología
18.
Front Immunol ; 15: 1200461, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39206204

RESUMEN

Dendritic cells (DCs) are known as unique professional antigen (Ag)-presenting cells (APCs) to prime naïve T cells for the initiation of adaptive immunity. While DCs are believed to play a pivotal role in generating anti-tumor T-cell responses, the importance of DCs in the protection from the progression of tumors remains elusive. Here, we show how the constitutive deficiency of CD11chi DCs influences the progression of tumors with the use of binary transgenic mice with constitutive loss of CD11chi DCs. Constitutive loss of CD11chi DCs not only enhances the progression of tumors but also reduces the responses of Ag-specific T cells. Furthermore, the congenital deficiency of CD11chi DCs generates the immunosuppressive tumor microenvironment (TME) that correlates with the marked accumulation of myeloid-derived suppressor cells (MDSCs) and the prominent productions of immunosuppressive mediators. Thus, our findings suggest that CD11chi DCs are crucial for generating anti-tumor T-cell responses and immunogenic TME to suppress the development of tumors.


Asunto(s)
Células Dendríticas , Ratones Transgénicos , Microambiente Tumoral , Animales , Células Dendríticas/inmunología , Microambiente Tumoral/inmunología , Ratones , Linfocitos T/inmunología , Células Supresoras de Origen Mieloide/inmunología , Células Supresoras de Origen Mieloide/metabolismo , Ratones Endogámicos C57BL , Antígeno CD11c/metabolismo , Neoplasias/inmunología , Línea Celular Tumoral
19.
Artículo en Inglés | MEDLINE | ID: mdl-37612162

RESUMEN

OBJECTIVE: Flap complications continue to be a challenge in microsurgical reconstruction for older adults. We aimed to evaluate the impact of age on surgical outcomes after microvascular reconstruction. STUDY DESIGN: We retrospectively investigated 103 patients with oral squamous cell carcinoma who had undergone microvascular reconstruction surgery to compare microsurgical reconstruction, common postoperative complications, and flap success rates in geriatric (>75 years) and non-geriatric (<75 years) patients. We also evaluated differences based on the American Society of Anesthesiologists Physical Status score. RESULTS: We found no significant differences between the geriatric and non-geriatric groups in peri-operative, postoperative, or general complications. Conversely, we found that delirium and aspiration pneumonia were significantly more likely to occur in geriatric patients and that multiple medical complications were significantly more likely to occur in geriatric patients with a high American Society of Anesthesiologists score. CONCLUSION: Microvascular reconstruction can be performed effectively and without excessive complications in geriatric patients, and age should not be considered a contraindication for this procedure. Comorbidities play a stronger role in the prediction of adverse events.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Procedimientos de Cirugía Plástica , Humanos , Anciano , Neoplasias de la Boca/cirugía , Carcinoma de Células Escamosas/cirugía , Estudios Retrospectivos , Complicaciones Posoperatorias/epidemiología , Neoplasias de Cabeza y Cuello/complicaciones , Resultado del Tratamiento
20.
Toxics ; 12(2)2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38393216

RESUMEN

Mechanically fibrillated cellulose nanofibers, known as fib-CNF (fiber length: 500 nm; diameter: 45 nm), are used in composites and as a natural thickener in foods. To evaluate their safety, we conducted a 28-day study in mice with inhalation exposure at 0.2 mg/body and oral administration of 400 mg/kg/day. Inhalation exposure to fib-CNF caused transient weight loss, changes in blood cell counts, and increased lung weights. These changes were attributed to adaptive responses. The oral administration of fib-CNF for 28 days resulted in no apparent toxic effects except for a slight decrease in platelet counts. The fib-CNF administration using the protocols studied appears to be safe in mice.

SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda