肿瘤的自身攻击——未来的癌症治疗策略 (from DXY)

dr.qinan

http://www.sciencedaily.com/releases/2010/04/100429093603.htm

Cancer Tumours That Fight Themselves

ScienceDaily (Apr. 30, 2010) — Cancer cells producing toxins that destroy tumours -- could this be a future treatment for cancer? Researchers at Lund University have achieved good results in tests on both cells and animals.

The results have now been presented in the respected scientific journal Cancer Research.

"We have previously discovered that a carbohydrate, xylose, linked to a naphthalene preferentially inhibits growth of tumour cells but not normal cells" says Katrin Mani.

This is something the researchers have been aware of for around 10 years. Since then, they have been working on the mechanism of action of the drug to try to understand why the xylose compound works so well against tumour cells.

Two research groups, led by Katrin Mani and Ulf Ellervik, have utilised natural biological processes and tested their ideas in animal experiments, which show up to 97% reduction in tumour growth. The researchers have found that when the cells are grown together with certain xylose-containing compounds, they begin to produce long carbohydrate chains called glycosaminoglycans (GAG). Different cell types produce different glycosaminoglycans, which are usually transported out of the cell.

"Glycosaminoglycans from normal cells are completely inactive. However, glycosaminoglycans from cancer cells are very active. They are quickly taken up by both normal and cancer cells and transported to the cell nuclei where they affect gene transcription and induce an antiproliferative effect, accompanied by apoptosis (cell death). The specific carbohydrate chains from tumour cells are in practice toxins," says Katrin Mani.

"Around the tumour, where there are lots of cancer cells, a high concentration of the toxin is built up. This means that the tumour produces a toxin that kills itself. When the tumour is gone, no more toxin will be produced," says Ulf Ellervik. It takes many years to develop an anticancer drug that can be used on patients. However, this is an important step on the way.

"So far all types of tumour we have tested have reacted in the same way and we are very hopeful for the future research results."
肿瘤的自身攻击

科学日报（2010年4月30日）—癌细胞产生自我摧毁的毒素，这会是未来治疗癌症的手段吗？Lund大学的研究者在细胞和动物实验上已经取得了可喜的成果。

这些研究成果已在备受尊崇的科学期刊《癌症研究》上发表。

“我们在之前的研究中已经发现一种将碳水化合物、木糖连接在萘上的化合物可以选择性抑制肿瘤细胞的生长，但不影响正常细胞”Katrin Mani说。

这是研究者们已经知道约10年的结论。从那时起，他们一直致力于该药物起效的作用机制研究从而试图理解为什么木糖复合物有如此优异的对抗肿瘤细胞的作用。

由Katrin Mani和Ulf Ellervik牵头的两个研究小组，利用自然生物过程并在动物实验中验证他们的设想，结果显示在肿瘤生长中有高达97%的下降。研究人员发现，当细胞在含有一定木糖化合物的环境生长时，就会产生一种叫做糖胺聚糖（GAG）的长链碳水化合物。不同类型的细胞产生不同的糖胺聚糖，通常运出细胞。

“正常细胞来源的糖胺聚糖是完全无效的，然而，癌细胞来源的糖胺聚糖却十分活跃。他们很快被正常细胞和癌细胞同时摄取，转运至细胞核从而影响基因的转录并诱导抗增殖作用，同时伴随细胞凋亡（死亡）。来源于肿瘤细胞的特异性糖链实际上是有毒的”Katrin Mani说。

“在肿瘤周围，那儿有大量的癌细胞，因此具有高浓度的毒素。这意味着肿瘤产生自我摧毁的毒素。当肿瘤消失了，便不再会有毒素的生成” Ulf Ellervik说。虽然用了很多年才开发出能在患者身上使用的抗癌药物，但这是治疗癌症道路上的重要一步。

“到目前为止，我们已测试的所有类型的肿瘤均以同样方式产生反应。我们对未来的研究成果抱有极大的希望。”