Bves/popdc1、popdc3在结直肠癌中的表达和意义

背景:结直肠癌为常见消化道恶性肿瘤,较易发生肝、肺等远处转移,预测其远处转移风险对于指导综合治疗和判断预后具有重要意义。细胞黏附分子与肿瘤侵袭、转移关系密切。目的:检测结直肠癌组织中的细胞黏附分子Bves/popdc1、popdc3表达,探讨两者在结直肠癌侵袭、转移中的可能作用。方法:选择15例正常结直肠组织和70例结直肠癌手术标本,以免疫组化方法检测Bves/popdc1、popdc3表达,分析结直肠癌组织中的Bves/popdc1、popdc3表达与肿瘤临床病理特征的关系以及两种蛋白表达之间的相关性。结果:Bves/popdc1、popdc3在结直肠癌组织中以低表达为主,高表达率显著低于正常结直肠组织(Bves/popdc1:25.7%对86.7%,P=0.000;popdc3:20.0%对73.3%,P=0.000)。结直肠癌组织中的Bves/popdc1、popdc3低表达与肿瘤分化程度呈负相关(P<0.05),与肿瘤浸润、淋巴结转移、远处转移和TNM分期呈正相关(P<0.05)。Bves/popdc1与popdc3在结直肠癌组织中的表达呈显著正相关(P<0.01)。结论:Bves/popdc1、popdc3在结直肠癌组织中表达下调,并与肿瘤临床分期和转移相关,提示两者在结直肠癌的侵袭、转移中起一定作用。     

果蝇Bves蛋白的表达、纯化及多克隆抗体的制备

目的为了进一步研究细胞粘附分子Bves在肿瘤的发生及转移过程中的作用,需要获得Bves蛋白并制备其抗体。方法根据Flybase网站所提供的Bves基因序列,以果蝇的总RNA为模板进行PCR扩增,得到Bves部分编码序列,随后将其连接到pET-28a载体上获得原核表达载体。重组表达质粒经酶切测序鉴定后,转化入大肠杆菌BL21感受态细胞中,并用IPTG诱导融合蛋白的表达,使用活化的Ni-IDA凝胶柱亲和纯化,将纯化后得到的His-Bves融合蛋白免疫注射新西兰大白兔制备Bves多克隆抗体,并用Western blot对抗体效价进行检测。结果和结论获得了Bves原核表达重组融合蛋白及高效价的兔抗Bves多克隆抗体,为后期深入研究Bves基因的功能奠定了基础。     

Thymosin β4 mediated PKC activation is essential to initiate the embryonic coronary developmental program and epicardial progenitor cell activation in adult mice in vivo

Hypoxic heart disease is a predominant cause of disability and death worldwide. Since adult mammalian hearts are incapable of regeneration after hypoxia, attempts to modify this deficiency are critical. As demonstrated in zebrafish, recall of the embryonic developmental program may be the key to success. Because thymosin β4 (TB4) is beneficial for myocardial cell survival and essential for coronary development in embryos, we hypothesized that it reactivates the embryonic developmental program and initiates epicardial progenitor mobilization in adult mammals. We found that TB4 stimulates capillary-like tube formation of adult coronary endothelial cells and increases embryonic endothelial cell migration and proliferation in vitro. The increase of blood vessel/epicardial substance (Bves) expressing cells accompanied by elevated VEGF, Flk-1, TGF-β, Fgfr-2, Fgfr-4, Fgf-17 and β-Catenin expression and increase of Tbx-18 and Wt-1 positive myocardial progenitors suggested organ-wide recall of the embryonic program in the adult epicardium. TB4 also positively regulated the expression and phosphorylation of myristoylated alanine-rich C-kinase substrate (Marcks), a direct substrate and indicator of protein kinase C (PKC) activity in vitro and in vivo. PKC inhibition significantly reduced TB4 initiated epicardial thickening, capillary growth and the number of myocardial progenitors. Our results demonstrate that TB4 is the first known molecule capable of organ-wide activation of the embryonic coronary developmental program in the adult mammalian heart after systemic administration and that PKC plays a significant role in the process.