RESUMO
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.
Assuntos
Janus Quinase 2/metabolismo , Luciferases/biossíntese , Medições Luminescentes , Policitemia Vera/enzimologia , Policitemia Vera/patologia , Animais , Diferenciação Celular/genética , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/uso terapêutico , Janus Quinase 2/antagonistas & inibidores , Janus Quinase 2/genética , Luciferases/genética , Camundongos , Camundongos Mutantes , Mutação de Sentido Incorreto , Células NIH 3T3 , Policitemia Vera/tratamento farmacológico , Policitemia Vera/genética , Células-Tronco/enzimologia , Células-Tronco/patologiaRESUMO
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.
Assuntos
Proteínas de Ligação a Selênio/metabolismo , Selênio/metabolismo , Ubiquitina Tiolesterase/metabolismo , Linhagem Celular Tumoral , Humanos , Proteínas de Ligação a Selênio/genética , Técnicas do Sistema de Duplo-Híbrido , Ubiquitina Tiolesterase/genética , UbiquitinaçãoRESUMO
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.