根据威克森林大学医学院 (Wake Forest University School of Medicine)的一项研究结果发现，原本用来调控血压的一个荷尔蒙分子，居然可以在小鼠肺癌的实验动物模型中，发现抑制肿瘤生长的效果。
据该研究团队发表在最新一期癌症研究 (Cancer Research)的论文显示，这次研究人员发现具有抑癌效果的分子，就是称为 angiotensin-(1-7)血压调控荷尔蒙，就过去的数据显示 angiotensin-(1-7)这个荷尔蒙发现于 1988年，它是身体里控制血压的关键分子，血管壁会因为此一荷尔蒙的作用，因而放松进而扩大管径，血管中的压力自然会因此而舒缓下来。
这次研究人员确定 angiotensin-(1-7)血压调控荷尔蒙的施用，可以使小鼠肺部的肿瘤体积，至少缩小 30%以上，而没有施用血压调控荷尔蒙的小鼠，肺部的肿瘤尺寸，足足放大了一倍。
虽然研究人员至今还不能完全掌握这个抑癌作用的机制，但这个新发现的线索，很可能在未来，成为每年全美地区十七万新增肺癌病患的希望。
(资料来源 : Bio.com)
部分英文原文：
Experimental Therapeutics, Molecular Targets, and Chemical Biology
Angiotensin-(1-7) Inhibits Growth of Human Lung Adenocarcinoma Xenografts in Nude Mice through a Reduction in Cyclooxygenase-2
Jyotsana Menon1,2, David R. Soto-Pantoja1, Michael F. Callahan2, J. Mark Cline3, Carlos M. Ferrario1,2, E. Ann Tallant1,2 and Patricia E. Gallagher1,2
1 Hypertension and Vascular Research Center and Departments of 2 Physiology and Pharmacology and 3 Pathology, Wake Forest University School of Medicine, Winston-Salem, North Carolina
Requests for reprints: Patricia E. Gallagher, The Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1032. Phone: 336-716-4455; Fax: 336-716-2456; E-mail: pgallagh@wfubmc.edu .
Angiotensin-(1-7) [Ang-(1-7)] is an endogenous peptide of the renin-angiotensin system with vasodilator and antiproliferative properties. Our previous studies showed that Ang-(1-7) reduced serum-stimulated growth of human lung cancer cells in vitro through activation of a unique AT(1-7) receptor. The current study investigates the effect of Ang-(1-7) on lung tumor growth in vivo, using a human lung tumor xenograft model. Athymic mice with tumors resulting from injection of A549 human lung cancer cells were treated for 28 days with either i.v. saline or Ang-(1-7), delivered by implanted osmotic mini-pumps. Treatment with Ang-(1-7) reduced tumor volume by 30% compared with the size before treatment; in contrast, tumor size in the saline-treated animals increased 2.5-fold. These results correlate with a reduction in the proliferation marker Ki67 in the Ang-(1-7)–infused tumors when compared with the saline-infused tumor tissues. Treatment with Ang-(1-7) significantly reduced cyclooxygenase-2 (COX-2) mRNA and protein in tumors of Ang-(1-7)–infused mice when compared with mice treated with saline as well as in the parent A549 human lung cancer cells in tissue culture. These results suggest that Ang-(1-7) may decrease COX-2 activity and proinflammatory prostaglandins to inhibit lung tumor growth. In contrast, the heptapeptide had no effect on COX-1 mRNA in xenograft tumors or A549 cells. Because Ang-(1-7), a peptide with antithrombotic properties, reduces growth through activation of a selective AT(1-7) receptor, our results suggest that the heptapeptide represents a novel treatment for lung cancer by reducing COX-2. [Cancer Res 2007; 67(6):2809–15]
