砷纳米粒子可用于预防乳腺癌
文章来源:未知 文章作者:meng 发布时间:2010-07-16 06:01 字体: [ ]  进入论坛
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You can teach an old drug new chemotherapy(化学疗法) tricks. Northwestern University researchers took a drug therapy proven for blood cancers but ineffective against solid tumors, packaged it with nanotechnology and got it to combat an aggressive type of breast cancer prevalent in young women, particularly young African-American women. That drug is arsenic2 trioxide(三氧化二砷,砒霜) , long part of the arsenal3 of ancient Chinese medicine and recently adopted by Western oncologists(肿瘤学家) for a type of leukemia(白血病) . The cancer is triple negative breast cancer, which often doesn't respond well to traditional chemotherapy and can't be treated by potentially life-saving targeted therapies. Women with triple negative breast cancer have a high risk of the cancer metastasizing and poor survival rates.

Prior to the new research, arsenic hadn't been effective in solid tumors. After the drug was injected into the bloodstream, it was excreted(排泄,分泌) too rapidly to work. The concentration of arsenic couldn't be increased, because it was then too toxic4.

A new arsenic nanoparticle –- designed to slip undetected through the bloodstream until it arrives at the tumor1 and delivers its poisonous cargo5 -- solved all that. The nanoparticle, called a nanobin, was injected into mice with triple negative breast tumors. Nanobins loaded with arsenic reduced tumor growth in mice, while the non-encapsulated arsenic had no effect on tumor growth. The arsenic nanobins blocked tumor growth by causing the cancer cells to die by a process known as apoptosis(细胞死亡) .

The nanobin consists of nanoparticulate arsenic trioxide encapsulated in a tiny fat vessel6 (a liposome) and coated with a second layer of a cloaking chemical that prolongs the life of the nanobin and prevents scavenger7 cells(巨噬细胞) from seeing it. The nanobin technology limits the exposure of normal tissue to the toxic drug as it passes through the bloodstream. When the nanobin gets absorbed by the abnormal, leaky blood vessels8 of the tumor, the nanoparticles of arsenic are released and trapped inside the tumor cells.

"The anti-tumor effects of the arsenic nanobins against clinically aggressive triple negative breast tumors in mice are extremely encouraging," said Vince Cryns, associate professor of medicine and an endocrinologist at Northwestern Medicine and a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University. "There's an urgent need to develop new therapies for poor prognosis(不良预后) triple negative breast cancer."

Cryns and Tom O'Halloran, director of the Chemistry of Life Processes Institute at Northwestern, are senior authors of a paper on the research, which will be published July 15 in Clinical Cancer Research and featured on the journal cover. Richard Ahn, a student in the medical scientists training program at Northwestern, is lead author.

"Everyone said you can't use arsenic for solid tumors," said O'Halloran, also associate director of basic sciences at the Lurie Cancer Center. "That's because they didn't deliver it the right way. This new technology delivered the drug directly to the tumor, maintained its stability and shielded normal cells from the toxicity9. That's huge."

The nanoparticle technology has great potential for other existing cancer drugs that have been shelved because they are too toxic or excreted too rapidly, Cryns noted10. "We can potentially make those drugs more effective against solid tumors by increasing their delivery to the tumor and by shielding normal cells from their toxicity," he said. "This nanotechnology platform has the potential to expand our arsenal of chemotherapy drugs to treat cancer."

"Working with both professors O'Halloran and Cryns has enabled us to develop the nanobins and hopefully create a new platform for the effective treatment of triple negative breast cancer," Ahn said. "Having both a basic science mentor11 and breast cancer mentor is ideal training for me as a future physician-scientist."

Looking ahead, the challenge now is to refine and improve the technology. "How do we make it more toxic to cancer cells and less toxic to healthy cells?" asked Cryns, also the director of SUCCEED, a Northwestern Medicine program to improve the quality of life for breast cancer survivors12.

Northwestern scientists are working on decorating the nanobins with antibodies that recognize markers on tumor cells to increase the drug's uptake by the tumor. They also want to put two or more drugs into the same nanobin and deliver them together to the tumor.

"Once you fine-tune this, you could use what would otherwise be a lethal13 or highly toxic dose of the drug, because a good deal of it will be directly released in the tumor," O'Halloran said.



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1 tumor fKxzm     
n.(肿)瘤,肿块(英)tumour
参考例句:
  • He was died of a malignant tumor.他死于恶性肿瘤。
  • The surgeons irradiated the tumor.外科医生用X射线照射那个肿瘤。
2 arsenic 2vSz4     
n.砒霜,砷;adj.砷的
参考例句:
  • His wife poisoned him with arsenic.他的妻子用砒霜把他毒死了。
  • Arsenic is a poison.砒霜是毒药。
3 arsenal qNPyF     
n.兵工厂,军械库
参考例句:
  • Even the workers at the arsenal have got a secret organization.兵工厂工人暗中也有组织。
  • We must be the great arsenal of democracy.我们必须成为民主的大军火库。
4 toxic inSwc     
adj.有毒的,因中毒引起的
参考例句:
  • The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
  • There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。
5 cargo 6TcyG     
n.(一只船或一架飞机运载的)货物
参考例句:
  • The ship has a cargo of about 200 ton.这条船大约有200吨的货物。
  • A lot of people discharged the cargo from a ship.许多人从船上卸下货物。
6 vessel 4L1zi     
n.船舶;容器,器皿;管,导管,血管
参考例句:
  • The vessel is fully loaded with cargo for Shanghai.这艘船满载货物驶往上海。
  • You should put the water into a vessel.你应该把水装入容器中。
7 scavenger LDTyN     
n.以腐尸为食的动物,清扫工
参考例句:
  • He's just fit for a job as scavenger.他只配当个清道夫。
  • He is not a scavenger nor just a moving appetite as some sharks are.它不是食腐动物,也不像有些鲨鱼那样,只知道游来游去满足食欲。
8 vessels fc9307c2593b522954eadb3ee6c57480     
n.血管( vessel的名词复数 );船;容器;(具有特殊品质或接受特殊品质的)人
参考例句:
  • The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
  • All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》
9 toxicity InYwc     
n.毒性,毒力
参考例句:
  • The hoarse grunt or squeal is characteristic of toxicity.嘶哑的哼声和叫声是中毒的特征。
  • Dieldrin is related to aldrin,and its toxicity to earthworms is similar.狄氏剂与艾氏剂有关,对蚯蚓的毒性是相似的。
10 noted 5n4zXc     
adj.著名的,知名的
参考例句:
  • The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
  • Jim is noted for arriving late for work.吉姆上班迟到出了名。
11 mentor s78z0     
n.指导者,良师益友;v.指导
参考例句:
  • He fed on the great ideas of his mentor.他以他导师的伟大思想为支撑。
  • He had mentored scores of younger doctors.他指导过许多更年轻的医生。
12 survivors 02ddbdca4c6dba0b46d9d823ed2b4b62     
幸存者,残存者,生还者( survivor的名词复数 )
参考例句:
  • The survivors were adrift in a lifeboat for six days. 幸存者在救生艇上漂流了六天。
  • survivors clinging to a raft 紧紧抓住救生筏的幸存者
13 lethal D3LyB     
adj.致死的;毁灭性的
参考例句:
  • A hammer can be a lethal weapon.铁锤可以是致命的武器。
  • She took a lethal amount of poison and died.她服了致命剂量的毒药死了。
TAG标签: cancer drug arsenic
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