既往大量的研究表明阿司匹林有抗癌作用，人们也一直认为其抗癌作用是通过能阻断环氧合酶来实现。据路透社10月2日报道，最新的研究表明，切断肿瘤血液供应才是阿司匹林抗癌的最主要机制。
来自英国Newcastle大学的Helen M. Arthur和同事们为了探索阿司匹林抗癌的潜在机制，将血管细胞暴露于阿司匹林或者西乐葆（塞来考昔）等能够阻断各种环氧合酶的药物。阿司匹林在稍微高于控制疼痛的剂量下，能够引起血管细胞的死亡，而在标准剂量下，阿司匹林并不影响细胞，但似乎能瓦解那些对血管起支撑结构的周围蛋白。西乐葆等别的药物，仅仅作用于环氧合酶，并不具有这些作用。
Arthur博士说，我们的研究显示阿司匹林的抗癌作用可能部分归功于它限制生长中肿瘤的血液供应，这能够限制肿瘤的生长。由于诸多作用仅在高剂量才会出现，因此阿司匹林不太可能作为一种合适的抗癌疗法，尽管如此，弄清楚药物如何发挥作用可能会产生新的疗法。下一步试验将研究阿司匹林这种作用的机制，这将帮助我们鉴定治疗癌症的新药。
这项研究发表在在《美国实验生物学会联合会杂志》上。
Anti-cancer effect of aspirin clarified
Last Updated: 2006-10-02 16:49:42 -0400 (Reuters Health)
By David Douglas
NEW YORK (Reuters Health) - Previous research has shown a possible anti-cancer effect for aspirin. Now, new findings suggest that the drug achieves this by cutting off the tumor's blood supply, not just by blocking an enzyme called cyclooxygenase.
While aspirin may not represent a suitable treatment for cancer, since many of the effects are only seen at very high doses, understanding how the drug works may lead to new therapies.
"Our work," senior investigator Dr. Helen M. Arthur told Reuters Health, "shows that the protective effects of aspirin against cancer may be partly due to the ability of aspirin to restrict the blood supply to a developing tumor, which limits tumor growth."
To investigate underlying processes, Arthur, from the University of Newcastle in the UK, and colleagues exposed blood vessel cells to aspirin or to drugs like Celebrex (celecoxib), which block various forms of cyclooxygenase.
In the Federation of American Societies for Experimental Biology (FASE
Journal, the researchers report that aspirin, at doses well above what is typically used for pain control, caused death of the blood vessel cells.
At standard doses, aspirin did not affect the cells, but seemed to disrupt the surrounding proteins that provide a support structure for blood vessels.
Celebrex and the other drugs, which largely target just cyclooxygenase, did not show these effects.
"The next stage in this research is to discover the mechanism by which aspirin can do this, which will also help us to identify new drug targets to treat cancer," Arthur concluded.
SOURCE: FASEB Journal, October 2006.
编辑：蓝色幻想
