干细胞可用来治疗很多疾病。包括心脏问题、痴呆症和帕金森氏症。但是因为人类卵子捐赠者的缺乏，科学家提议用人兽混合胚胎作为合成大量人类克隆胚胎的方式来获得干细胞。但是最新研究显示。人兽胚胎很难成功。该研究报告发表于《克隆...干细胞可用来治疗很多疾病。包括心脏问题、痴呆症和帕金森氏症。但是因为人类卵子捐赠者的缺乏，科学家提议用人兽混合胚胎作为合成大量人类克隆胚胎的方式来获得干细胞。但是最新研究显示。人兽胚胎很难成功。该研究报告发表于《克隆和干细胞》（CLONING AND STEM CELLS）杂志。人兽混合医用胚胎从一开始便引起很大争议，但一些科学家对这项研究寄予厚望，认为它可以帮助科学家找到某些疑难疾病的治疗方法。但科学家现在发现，有关创造人兽混合医用胚胎的研究可能注定会以失败告终。展开更多
Wnts are secreted lipid-modified signaling proteins that influence multiple processes ranging from cell proliferation and differentiation, fate decisions, apoptosis, axial polarity and axonal guidance to stem cell los...Wnts are secreted lipid-modified signaling proteins that influence multiple processes ranging from cell proliferation and differentiation, fate decisions, apoptosis, axial polarity and axonal guidance to stem cell loss, kidney and reproductive tract defects. Activation of Wnt signalling in many tissues has also been associated with cancer. In many eukaryotes, expression of nuclear-encoded mRNA can be strongly inhibited by the presence of a small double-stranded RNA corresponding to exon sequences in the mRNA. In this study, human Wnt9a was cloned from undifferentiated hES cells. The results of immunohistochemistry showed that Wnt9a protein was expressed in undifferentiated hES cells, pAVU6＋27 vectors were used to construct the siRNA expression vectors for human Wnt9a One kind of small interfering RNA inserts was designed, synthesized and tested for human Wnt9a. The results of in situ hybridization demonstrated that Wntga signal was dramatically reduced in the cells transfected with U6＋27/siWnt9a compared to the untransfected cells. The results of flow cytometry analysis showed that the human breast cancer MCF-7 cells proliferation was promoted after lowering the expression of human Wnt9a by RNAi, but inhibited after over-expression of human Wnt9a. All those suggest the expression level of human Wnt9a may play a role in adjusting the rate of cell proliferation ofhES and MCF-7 cells.展开更多
文摘干细胞可用来治疗很多疾病。包括心脏问题、痴呆症和帕金森氏症。但是因为人类卵子捐赠者的缺乏，科学家提议用人兽混合胚胎作为合成大量人类克隆胚胎的方式来获得干细胞。但是最新研究显示。人兽胚胎很难成功。该研究报告发表于《克隆和干细胞》（CLONING AND STEM CELLS）杂志。人兽混合医用胚胎从一开始便引起很大争议，但一些科学家对这项研究寄予厚望，认为它可以帮助科学家找到某些疑难疾病的治疗方法。但科学家现在发现，有关创造人兽混合医用胚胎的研究可能注定会以失败告终。
基金Acknowledgment This work was supported by grants from the National Nature Science Foundation of China （No.31071091 No.30971570 No.31171196） and Department of Education Key Project of HuNan Province, China （NO：09A035 and NO：06C370）.
文摘Wnts are secreted lipid-modified signaling proteins that influence multiple processes ranging from cell proliferation and differentiation, fate decisions, apoptosis, axial polarity and axonal guidance to stem cell loss, kidney and reproductive tract defects. Activation of Wnt signalling in many tissues has also been associated with cancer. In many eukaryotes, expression of nuclear-encoded mRNA can be strongly inhibited by the presence of a small double-stranded RNA corresponding to exon sequences in the mRNA. In this study, human Wnt9a was cloned from undifferentiated hES cells. The results of immunohistochemistry showed that Wnt9a protein was expressed in undifferentiated hES cells, pAVU6＋27 vectors were used to construct the siRNA expression vectors for human Wnt9a One kind of small interfering RNA inserts was designed, synthesized and tested for human Wnt9a. The results of in situ hybridization demonstrated that Wntga signal was dramatically reduced in the cells transfected with U6＋27/siWnt9a compared to the untransfected cells. The results of flow cytometry analysis showed that the human breast cancer MCF-7 cells proliferation was promoted after lowering the expression of human Wnt9a by RNAi, but inhibited after over-expression of human Wnt9a. All those suggest the expression level of human Wnt9a may play a role in adjusting the rate of cell proliferation ofhES and MCF-7 cells.
