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2.
Mol Biomed ; 1(1): 6, 2020 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-35006413

RESUMEN

Toll-like receptors (TLRs) are a family of proteins that recognize pathogen associated molecular patterns (PAMPs). Their primary function is to activate innate immune responses while also involved in facilitating adaptive immune responses. Different TLRs exert distinct functions by activating varied immune cascades. Several TLRs are being pursued as cancer drug targets. We discovered a novel, highly potent and selective small molecule TLR8 agonist DN052. DN052 exhibited strong in vitro cellular activity with EC50 at 6.7 nM and was highly selective for TLR8 over other TLRs including TLR4, 7 and 9. DN052 displayed excellent in vitro ADMET and in vivo PK profiles. DN052 potently inhibited tumor growth as a single agent. Moreover, combination of DN052 with the immune checkpoint inhibitor, selected targeted therapeutics or chemotherapeutic drugs further enhanced efficacy of single agents. Mechanistically, treatment with DN052 resulted in strong induction of pro-inflammatory cytokines in ex vivo human PBMC assay and in vivo monkey study. GLP toxicity studies in rats and monkeys demonstrated favorable safety profile. This led to the advancement of DN052 into phase 1 clinical trials.

3.
PLoS One ; 7(5): e37207, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22623993

RESUMEN

A high percentage of patients with the myeloproliferative disorder polycythemia vera (PV) harbor a Val617→Phe activating mutation in the Janus kinase 2 (JAK2) gene, and both cell culture and mouse models have established a functional role for this mutation in the development of this disease. We describe the properties of MRLB-11055, a highly potent inhibitor of both the WT and V617F forms of JAK2, that has therapeutic efficacy in erythropoietin (EPO)-driven and JAK2V617F-driven mouse models of PV. In cultured cells, MRLB-11055 blocked proliferation and induced apoptosis in a manner consistent with JAK2 pathway inhibition. MRLB-11055 effectively prevented EPO-induced STAT5 activation in the peripheral blood of acutely dosed mice, and could prevent EPO-induced splenomegaly and erythrocytosis in chronically dosed mice. In a bone marrow reconstituted JAK2V617F-luciferase murine PV model, MRLB-11055 rapidly reduced the burden of JAK2V617F-expressing cells from both the spleen and the bone marrow. Using real-time in vivo imaging, we examined the kinetics of disease regression and resurgence, enabling the development of an intermittent dosing schedule that achieved significant reductions in both erythroid and myeloid populations with minimal impact on lymphoid cells. Our studies provide a rationale for the use of non-continuous treatment to provide optimal therapy for PV patients.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Janus Quinasa 2/antagonistas & inhibidores , Policitemia Vera/tratamiento farmacológico , Animales , Western Blotting , Proliferación Celular/efectos de los fármacos , Ensayo de Unidades Formadoras de Colonias , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/uso terapéutico , Eritropoyetina/metabolismo , Citometría de Flujo , Humanos , Ratones , Ratones Endogámicos C57BL , Factor de Transcripción STAT5/metabolismo
4.
Zhonghua Liu Xing Bing Xue Za Zhi ; 32(8): 816-20, 2011 Aug.
Artículo en Chino | MEDLINE | ID: mdl-22093475

RESUMEN

OBJECTIVE: To investigate the risk factors and establish the Cox's regression model on the recurrence of ischemic stroke. METHODS: We retrospectively reviewed consecutive patients with ischemic stroke admitted to the Neurology Department of the Hebei United University Affiliated Hospital between January 1, 2008 and December 31, 2009. Cases had been followed since the onset of ischemic stroke. The follow-up program was finished in June 30, 2010. Kaplan-Meier methods were used to describe the recurrence rate. Monovariant and multivariate Cox's proportional hazard regression model were used to analyze the risk factors associated to the episodes of recurrence. And then, a recurrence model was set up. RESULTS: During the period of follow-up program, 79 cases were relapsed, with the recurrence rates as 12.75% in one year and 18.87% in two years. Monovariant and multivariate Cox's proportional hazard regression model showed that the independent risk factors that were associated with the recurrence appeared to be age (X1) (RR = 1.025, 95%CI: 1.003 - 1.048), history of hypertension (X2) (RR = 1.976, 95%CI: 1.014 - 3.851), history of family strokes (X3) (RR = 2.647, 95%CI: 1.175 - 5.961), total cholesterol amount (X4) (RR = 1.485, 95%CI: 1.214 - 1.817), ESRS total scores (X5) (RR = 1.327, 95%CI: 1.057 - 1.666) and progression of the disease (X6) (RR = 1.889, 95%CI: 1.123 - 3.178). Personal prognosis index (PI) of the recurrence model was as follows: PI = 0.025X1 + 0.681X2 + 0.973X3 + 0.395X4 + 0.283X5 + 0.636X6. The smaller the personal prognosis index was, the lower the recurrence risk appeared, while the bigger the personal prognosis index was, the higher the recurrence risk appeared. CONCLUSION: Age, history of hypertension, total cholesterol amount, total scores of ESRS, together with the disease progression were the independent risk factors associated with the recurrence episodes of ischemic stroke. Both recurrence model and the personal prognosis index equation were successful constructed.


Asunto(s)
Isquemia Encefálica/epidemiología , Accidente Cerebrovascular/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Modelos de Riesgos Proporcionales , Recurrencia , Estudios Retrospectivos , Factores de Riesgo
6.
Proc Natl Acad Sci U S A ; 107(12): 5511-5, 2010 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-20212136

RESUMEN

Rpa1, an essential gene involved in DNA replication and genome maintenance, is syntenic and linked to Trp53 in mice and humans. To study the genetic interaction between Rpa1 and Trp53 in tumorigenesis, we generated compound Rpa1(L230P/+); Trp53(+/-) mutant mice with the mutant alleles in either trans or cis configuration. We demonstrate that the Rpa1(L230P) missense mutation significantly alters the tumor phenotype and spectrum of Trp53 mutant mice by modifying the genetic mechanisms underlying tumorigenesis. Importantly, when the Rpa1(L230P) and Trp53 mutant alleles are in cis, the tumor phenotype is attenuated and altered and loss of heterozygosity (LOH) at the Trp53 wild-type locus is selected against, whereas in the trans configuration, Rpa1(L230P) enhances the Trp53(+/-) tumor phenotype even though Rpa1(L230P) is ultimately lost by LOH. These studies indicate that polymorphic genetic variants in cell essential genes can genetically affect closely linked tumor suppressor loci via allelic phasing, which can result in profound phenotypic variations in tumorigenesis.


Asunto(s)
Genes p53 , Neoplasias Experimentales/genética , Proteína de Replicación A/genética , Animales , Cruzamientos Genéticos , Epistasis Genética , Femenino , Prueba de Complementación Genética , Inestabilidad Genómica , Pérdida de Heterocigocidad , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Mutantes , Modelos Genéticos , Mutación Missense , Fenotipo
7.
PLoS One ; 4(9): e7286, 2009 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-19789710

RESUMEN

Splenic enlargement (splenomegaly) develops in numerous disease states, although a specific pathogenic role for the spleen has rarely been described. In polycythemia vera (PV), an activating mutation in Janus kinase 2 (JAK2(V617)) induces splenomegaly and an increase in hematocrit. Splenectomy is sparingly performed in patients with PV, however, due to surgical complications. Thus, the role of the spleen in the pathogenesis of human PV remains unknown. We specifically tested the role of the spleen in the pathogenesis of PV by performing either sham (SH) or splenectomy (SPL) surgeries in a murine model of JAK2(V617F)-driven PV. Compared to SH-operated mice, which rapidly develop high hematocrits after JAK2(V617F) transplantation, SPL mice completely fail to develop this phenotype. Disease burden (JAK2(V617)) is equivalent in the bone marrow of SH and SPL mice, however, and both groups develop fibrosis and osteosclerosis. If SPL is performed after PV is established, hematocrit rapidly declines to normal even though myelofibrosis and osteosclerosis again develop independently in the bone marrow. In contrast, SPL only blunts hematocrit elevation in secondary, erythropoietin-induced polycythemia. We conclude that the spleen is required for an elevated hematocrit in murine, JAK2(V617F)-driven PV, and propose that this phenotype of PV may require a specific interaction between mutant cells and the spleen.


Asunto(s)
Hematócrito , Janus Quinasa 2/genética , Policitemia Vera/sangre , Policitemia Vera/cirugía , Esplenectomía/métodos , Alelos , Animales , Médula Ósea/metabolismo , Trasplante de Médula Ósea , Eritropoyetina/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Mutación , Fenotipo , Bazo/metabolismo
8.
Biochim Biophys Acta ; 1792(11): 1073-9, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19715759

RESUMEN

Polycythemia vera (PV) is a myeloproliferative disorder involving hematopoietic stem cells. A recurrent somatic missense mutation in JAK2 (JAK2V617F) is thought to play a causal role in PV. Therefore, targeting Jak2 will likely provide a molecular mechanism-based therapy for PV. To facilitate the development of such new and specific therapeutics, a suitable and well-characterized preclinical animal model is essential. Although several mouse models of PV have been reported, the spatiotemporal kinetics of PV formation and progression has not been studied. To address this, we created a bone marrow transplant mouse model that co-expresses mutant Jak2 and luciferase 2 (Luc2) genes. Bioluminescent imaging (BLI) was used to visualize disease cells and analyze the kinetics of PV development in vivo. To better understand the molecular mechanism of PV, we generated mice carrying a kinase inactive mutant Jak2 (Jak2K882E), demonstrating that the PV disease was dependent on constitutive activation of the Jak2 kinase activity. We further showed that the Jak2V617F mutation caused increased stem cell renewal activity and impaired cell differentiation, which was at least in part due to deregulated transcriptional programming. The Jak2V617F-Luc2 PV mice will be a useful preclinical model to characterize novel JAK2 inhibitors for the treatment of PV.


Asunto(s)
Janus Quinasa 2/metabolismo , Luciferasas/biosíntesis , Mediciones Luminiscentes , Policitemia Vera/enzimología , Policitemia Vera/patología , Animales , Diferenciación Celular/genética , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/uso terapéutico , Janus Quinasa 2/antagonistas & inhibidores , Janus Quinasa 2/genética , Luciferasas/genética , Ratones , Ratones Mutantes , Mutación Missense , Células 3T3 NIH , Policitemia Vera/tratamiento farmacológico , Policitemia Vera/genética , Células Madre/enzimología , Células Madre/patología
9.
Biochem Pharmacol ; 78(4): 382-9, 2009 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-19413997

RESUMEN

Polycythemia vera (PV) is a myeloproliferative disorder characterized by increased red cell mass and splenomegaly in the absence of secondary causes [Tefferi A., Spivak J.L., Polycythemia vera: scientific advances and current practice. Semin Hematol 2005;42(4):206-20.]. Recently, several laboratories have discovered that the vast majority of patients with PV carry a single, activating mutation (V617F) in the pseudokinase domain of Janus kinase 2 (Jak2) [Zhao R, Xing S, Li Z, Fu X, Li Q, Krantz SB, et al., Identification of an acquired JAK2 mutation in polycythemia vera. J Biol Chem 2005;280(24):22788-92; James C, Ugo V, Le Couédic JP, Staerk J, Delhommeau F, Lacout C, et al., A unique clonal JAK2 mutation leading to constitutive signalling causes polycythemia vera. Nature 2005;434(7037):1144-8; Kralovics R, Passamonti F, Buser AS, Teo SS, Tiedt R, Passweg JR, et al., A gain-of-function mutation of JAK2 in myeloproliferative disorders. N Engl J Med 2005;352(17):1779-90; Levine RL, Wadleigh M, Cools J, Ebert BL, Wernig G, Huntly BJ, et al., Activating mutation in the tyrosine kinase JAK2 in polycythemia vera, essential thrombocythemia, and myeloid metaplasia with myelofibrosis. Cancer Cell 2005;7(4):387-97.]. This discovery has spurred interest in developing therapies for PV via inhibition of Jak2. We induced polycythemia in mice by administering high dose recombinant erythropoietin (Epo) and determined that administration recapitulates almost all of the major and minor diagnostic features of human PV. We then tested a selective, small molecule inhibitor of Jak2 (Jak2i) and showed that this treatment prevents polycythemia. This prevention of polycythemia was accompanied by lower hematocrits, reduced spleen sizes and reductions in Stat5 phosphorylation (pStat5). Surprisingly, Epo rapidly (<1h) induces mobilization of activated erythroid precursors into the blood, thus allowing drug-response relationships to guide discovery. We conclude that inhibition of Jak2 prevents polycythemia in mice, and furthermore present this model as an efficient tool for the discovery of drugs that effectively treat human PV.


Asunto(s)
Inhibidores Enzimáticos/uso terapéutico , Janus Quinasa 2/antagonistas & inhibidores , Policitemia Vera/fisiopatología , Policitemia/prevención & control , Piridonas/uso terapéutico , Animales , Proliferación Celular , Inhibidores Enzimáticos/farmacología , Células Precursoras Eritroides , Humanos , Janus Quinasa 2/metabolismo , Ratones , Fosforilación , Mielofibrosis Primaria/fisiopatología , Proteínas Tirosina Quinasas/metabolismo , Piridonas/síntesis química , Piridonas/química , Transducción de Señal , Trombocitemia Esencial , Células Tumorales Cultivadas
10.
Biochem Biophys Res Commun ; 379(2): 583-8, 2009 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-19118533

RESUMEN

Reduced expression of the 56-kDa human selenium binding protein-1 (hSP56) has been reported in many types of human malignancies, including prostate, lung, ovarian, thyroid and colorectal cancers. hSP56 also has been implicated in selenium-dependent cell growth inhibition. However, the molecular basis of hSP56's function has not been elucidated. In the present study, we identified von Hippel-Lindau protein (pVHL)-interacting deubiquitinating enzyme 1 (VDU1) as a protein partner of hSP56 using a yeast two-hybrid screen. The interaction between hSP56 and VDU1 was confirmed by yeast two-hybrid analysis and in vitro binding experiments. hSP56 and VDU1 co-localized in the perinuclear region of LNCaP human prostate cancer cells. The full-length VDU1 specifically interacted with a selenium-replete form of hSP56. We also demonstrate stable incorporation of selenium into hSP56, in a mode distinct from conventional selenocysteine-containing selenoproteins. These findings suggest that hSP56 may play a role in ubiquitination/deubiquitination-mediated protein degradation pathways in a selenium-dependent manner.


Asunto(s)
Proteínas de Unión al Selenio/metabolismo , Selenio/metabolismo , Ubiquitina Tiolesterasa/metabolismo , Línea Celular Tumoral , Humanos , Proteínas de Unión al Selenio/genética , Técnicas del Sistema de Dos Híbridos , Ubiquitina Tiolesterasa/genética , Ubiquitinación
11.
PLoS Genet ; 4(6): e1000092, 2008 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-18551179

RESUMEN

DNA mismatch repair suppresses gastrointestinal tumorgenesis. Four mammalian E. coli MutL homologues heterodimerize to form three distinct complexes: MLH1/PMS2, MLH1/MLH3, and MLH1/PMS1. To understand the mechanistic contributions of MLH3 and PMS2 in gastrointestinal tumor suppression, we generated Mlh3(-/-);Apc(1638N) and Mlh3(-/-);Pms2(-/-);Apc(1638N) (MPA) mice. Mlh3 nullizygosity significantly increased Apc frameshift mutations and tumor multiplicity. Combined Mlh3;Pms2 nullizygosity further increased Apc base-substitution mutations. The spectrum of MPA tumor mutations was distinct from that observed in Mlh1(-/-);Apc(1638N) mice, implicating the first potential role for MLH1/PMS1 in tumor suppression. Because Mlh3;Pms2 deficiency also increased gastrointestinal tumor progression, we used array-CGH to identify a recurrent tumor amplicon. This amplicon contained a previously uncharacterized Transducin enhancer of Split (Tle) family gene, Tle6-like. Expression of Tle6-like, or the similar human TLE6D splice isoform in colon cancer cells increased cell proliferation, colony-formation, cell migration, and xenograft tumorgenicity. Tle6-like;TLE6D directly interact with the gastrointestinal tumor suppressor RUNX3 and antagonize RUNX3 target transactivation. TLE6D is recurrently overexpressed in human colorectal cancers and TLE6D expression correlates with RUNX3 expression. Collectively, these findings provide important insights into the molecular mechanisms of individual MutL homologue tumor suppression and demonstrate an association between TLE mediated antagonism of RUNX3 and accelerated human colorectal cancer progression.


Asunto(s)
Proteínas Portadoras/metabolismo , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Reparación de la Incompatibilidad de ADN , Amplificación de Genes , Proteínas Represoras/genética , Factores de Transcripción/genética , Proteína de la Poliposis Adenomatosa del Colon/genética , Proteína de la Poliposis Adenomatosa del Colon/metabolismo , Adenosina Trifosfatasas/genética , Adenosina Trifosfatasas/metabolismo , Empalme Alternativo , Animales , Secuencia de Bases , Proteínas Portadoras/genética , Línea Celular , Movimiento Celular , Proliferación Celular , Proteínas Co-Represoras , Neoplasias Colorrectales/fisiopatología , Subunidad alfa 3 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 3 del Factor de Unión al Sitio Principal/metabolismo , Enzimas Reparadoras del ADN/genética , Enzimas Reparadoras del ADN/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Progresión de la Enfermedad , Femenino , Dosificación de Gen , Humanos , Masculino , Ratones , Ratones Endogámicos , Ratones Desnudos , Ratones Transgénicos , Endonucleasa PMS2 de Reparación del Emparejamiento Incorrecto , Proteínas MutL , Mutación , Trasplante de Neoplasias , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Represoras/metabolismo , Factores de Transcripción/metabolismo , Activación Transcripcional , Trasplante Heterólogo
12.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 27(9): 844-6, 2007 Sep.
Artículo en Chino | MEDLINE | ID: mdl-17969903

RESUMEN

OBJECTIVE: Through supervising the construction of some key hospitals of integrated Chinese and Western medicine (ICWM), the characteristic indexes and problems concerning hospital construction were analyzed. It was pointed out that in order to improve the level of construction and administration of ICWM hospitals, the overall effect of construction should be paid attention to, the cultivation of ICWM professionals should be strengthened and the ICWM standard based assessment on clinical efficacy should be stressed. Besides, the strategies on administration pattern of ICWM hospitals were discussed.


Asunto(s)
Prestación Integrada de Atención de Salud/métodos , Medicina Integrativa/métodos , Medicina Tradicional China/métodos , Prestación Integrada de Atención de Salud/organización & administración , Prestación Integrada de Atención de Salud/normas , Administración Hospitalaria/normas , Humanos , Medicina Integrativa/organización & administración , Medicina Integrativa/normas , Medicina Tradicional China/normas , Medicina Tradicional China/tendencias
13.
Prostate ; 66(2): 135-45, 2006 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-16161153

RESUMEN

BACKGROUND: Erythropoietin (Epo), the principal regulator of erythroid progenitor survival, growth, and differentiation, initiates its action by binding to its cognate cell surface receptor (EpoR). EpoR have been identified on a variety of non-hematopoietic cells, both normal and malignant, however, little is known about the function of EpoR on malignant cells. METHODS: RT-PCR, Western blotting, and immunohistochemistry were used to demonstrate that prostate cancer cells express EpoR at both the gene and protein level. Cell proliferation assays and STAT5 phosphorylation were used to demonstrate Epo's mitogenic action and intracellular signaling, respectively. RESULTS: We have demonstrated that transformed prostate epithelial and prostate cancer cell lines, as well as primary prostate tissue, express the EpoR. Importantly, the EpoR on prostate cells are functional, as demonstrated by the observation that each of the cell lines exhibited a dose-dependent proliferative response to Epo, and that Epo triggered STAT5b phosphorylation in the cells. CONCLUSION: Human prostatic epithelial cells and prostate cancer cells express functional EpoR, and Epo serves as a growth factor for these cells. These results have implications for our understanding of normal prostatic growth and development and of the pathobiology of human prostate cancer.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Eritropoyetina/farmacología , Próstata/citología , Próstata/metabolismo , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Receptores de Eritropoyetina/metabolismo , Factor de Transcripción STAT5/metabolismo , Western Blotting , Línea Celular Transformada , Línea Celular Tumoral , Relación Dosis-Respuesta a Droga , Células Epiteliales/citología , Células Epiteliales/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunohistoquímica , Masculino , Fosforilación , ARN Mensajero/análisis , Receptores de Eritropoyetina/genética , Proteínas Recombinantes , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal
14.
Nucleic Acids Res ; 33(21): 6733-42, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16314305

RESUMEN

V(D)J recombination and class switch recombination are the two DNA rearrangement events used to diversify the mouse and human antibody repertoires. While their double strand breaks (DSBs) are initiated by different mechanisms, both processes use non-homologous end joining (NHEJ) in the repair phase. DNA mismatch repair elements (MSH2/MSH6) have been implicated in the repair of class switch junctions as well as other DNA DSBs that proceed through NHEJ. MSH2 has also been implicated in the regulation of factors such as ATM and the MRN (Mre11, Rad50, Nbs1) complex, which are involved in V(D)J recombination. These findings led us to examine the role of MSH2 in V(D)J repair. Using MSH2-/- and MSH2+/+ mice and cell lines, we show here that all pathways involving MSH2 are dispensable for the generation of an intact pre-immune repertoire by V(D)J recombination. In contrast to switch junctions and other DSBs, the usage of terminal homology in V(D)J junctions is not influenced by MSH2. Thus, whether the repair complex for V(D)J recombination is of a canonical NHEJ type or a separate microhomology-mediated-end joining (MMEJ) type, it does not involve MSH2. This highlights a distinction between the repair of V(D)J recombination and other NHEJ reactions.


Asunto(s)
Reordenamiento Génico de Linfocito B , Proteína 2 Homóloga a MutS/fisiología , Animales , Secuencia de Bases , Células de la Médula Ósea/inmunología , Línea Celular , Reparación del ADN , Fragmentos de Inmunoglobulinas/química , Fragmentos de Inmunoglobulinas/genética , Región de Unión de la Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Ratones , Ratones Noqueados , Proteína 2 Homóloga a MutS/genética , Recombinación Genética
15.
Nat Genet ; 37(7): 750-5, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15965476

RESUMEN

Most cancers have multiple chromosomal rearrangements; the molecular mechanisms that generate them remain largely unknown. Mice carrying a heterozygous missense change in one of the DNA-binding domains of Rpa1 develop lymphoid tumors, and their homozygous littermates succumb to early embryonic lethality. Array comparative genomic hybridization of the tumors identified large-scale chromosomal changes as well as segmental gains and losses. The Rpa1 mutation resulted in defects in DNA double-strand break repair and precipitated chromosomal breaks as well as aneuploidy in primary heterozygous mutant mouse embryonic fibroblasts. The equivalent mutation in yeast is hypomorphic and semidominant and enhanced the formation of gross chromosomal rearrangements in multiple genetic backgrounds. These results indicate that Rpa1 functions in DNA metabolism are essential for the maintenance of chromosomal stability and tumor suppression.


Asunto(s)
Inestabilidad Cromosómica/genética , Reparación del ADN/genética , Proteínas de Unión al ADN/genética , Mutación , Aneuploidia , Animales , Secuencia de Bases , Células Cultivadas , Proteínas de Unión al ADN/metabolismo , Pérdida del Embrión/genética , Femenino , Hematopoyesis , Heterocigoto , Hiperplasia , Cariotipificación , Tejido Linfoide/patología , Linfoma/genética , Linfoma/mortalidad , Linfoma/patología , Masculino , Ratones , Ratones Mutantes , Datos de Secuencia Molecular , Mutación Missense , Proteína de Replicación A , Factores de Tiempo , Levaduras/genética
16.
Cancer Res ; 64(2): 517-22, 2004 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-14744764

RESUMEN

Mutations in the human DNA mismatch repair gene MSH2 are associated with hereditary nonpolyposis colorectal cancer as well as a significant proportion of sporadic colorectal cancer. The inactivation of MSH2 results in the accumulation of somatic mutations in the genome of tumor cells and resistance to the genotoxic effects of a variety of chemotherapeutic agents. Here we show that the DNA repair and DNA damage-induced apoptosis functions of Msh2 can be uncoupled using mice that carry the G674A missense mutation in the conserved ATPase domain. As a consequence, although Msh2(G674A) homozygous mutant mice are highly tumor prone, the onset of tumorigenesis is delayed as compared with Msh2-null mice. In addition, tumors that carry the mutant allele remain responsive to treatment with a chemotherapeutic agent. Our results indicate that Msh2-mediated apoptosis is an important component of tumor suppression and that certain MSH2 missense mutations can cause mismatch repair deficiency while retaining the signaling functions that confer sensitivity to chemotherapeutic agents.


Asunto(s)
Apoptosis/genética , Reparación del ADN/genética , Proteínas de Unión al ADN , Mutación Puntual , Proteínas Proto-Oncogénicas/genética , Alanina , Sustitución de Aminoácidos , Animales , Disparidad de Par Base/genética , Cromosomas Artificiales Bacterianos , Cisplatino/toxicidad , Codón/genética , Daño del ADN/genética , Fibroblastos/fisiología , Glicina , Ratones , Proteína 2 Homóloga a MutS , Eliminación de Secuencia
17.
Int J Mol Med ; 11(4): 473-7, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12632100

RESUMEN

Heparin/heparan sulfate interacting protein (HIP) was initially identified as an adhesion molecule from a human uterine epithelial cell line. It was previously demonstrated that HIP was upregulated in human colorectal cancer. However, its expression was significantly lower in Dukes' D samples compared to earlier Dukes' stages suggesting that HIP was inversely correlated to metastasis. The present study shows the presence of mutations in human metastatic colorectal cancer tissue and a cell line. Interestingly, a 12-base deletion encoding the heparin/heparan sulfate binding motif was common between the metastatic tissue and cell line. There was no mutation in the primary carcinoma and normal tissue. The findings suggest an important role for HIP in colorectal cancer metastasis.


Asunto(s)
Factores de Coagulación Sanguínea , Proteínas Portadoras/genética , Neoplasias Colorrectales/genética , Mutación , Neoplasias Colorrectales/secundario , Humanos , Neoplasias Hepáticas/genética , Proteínas de Unión al ARN , Proteínas Ribosómicas , Análisis de Secuencia de ADN , Eliminación de Secuencia
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