RESUMO
Mammalian fertilization begins with the fusion of two specialized gametes, followed by major epigenetic remodeling leading to the formation of a totipotent embryo. During the development of the pre-implantation embryo, precise reprogramming progress is a prerequisite for avoiding developmental defects or embryonic lethality, but the underlying molecular mechanisms remain elusive. For the past few years, unprecedented breakthroughs have been made in mapping the regulatory network of dynamic epigenomes during mammalian early embryo development, taking advantage of multiple advances and innovations in low-input genome-wide chromatin analysis technologies. The aim of this review is to highlight the most recent progress in understanding the mechanisms of epigenetic remodeling during early embryogenesis in mammals, including DNA methylation, histone modifications, chromatin accessibility and 3D chromatin organization.
Assuntos
Animais , Feminino , Masculino , Camundongos , Montagem e Desmontagem da Cromatina , Metilação de DNA , Elementos de DNA Transponíveis , Embrião de Mamíferos , Desenvolvimento Embrionário/genética , Epigênese Genética , Epigenoma , Fertilização/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Código das Histonas , Histonas/metabolismo , Oócitos/metabolismo , Espermatozoides/metabolismoRESUMO
The breast cancer stem cell theory provides a theoretical basis for explaining phenotypic and functional heterogeneity of breast cancer. These breast cancer stem cells(CSCs)promote tumor growth and are closely related to breast cancer intrinsic drug resistance. Therefore,targeted therapy of breast CSCs has become a hot area in basic and clinical research. There is growing evidence that nanoparticles can kill cancer by targeting breast CSCs ,such as targeted tumor stem cell-specific expressed surface markers(AL-DH1,CD44,and CD90),tumor stem cell stemness-related NOTCH,Hedgehog and TGF-βsignaling pathways. In this review,we summarized the characteristics and research status of breast CSCs ,and the application of nanotechnology in the treatment of breast cancer.In addition,we also summarized the research status of epigenetic drugs aimed to restrain the reprogramming of breast cancer cells.
RESUMO
The process of ‘cell reprogramming’ can be achieved by somatic cell nuclear transfer, cell fusion with embryonic stem cells, exposure to stem cell extracts, or by inducing pluripotentcy mediated by defined factors giving rise to what are termed induced pluripotent stem cells. More recently, the fate of a somatic cell can be directly induced to uptake other cell fates, termed lineage-specific reprogramming, without the need to de-differentiate the cells to a pluripotent state. In this review we will describe the different methods of reprogramming somatic cells.