生物谷报道：利物浦大学研究人员发现两种分子在血液中相互作用，控制癌症细胞扩散。某些疾病如乳腺癌、肺癌及结肠直肠癌等，受累细胞生长失去控制，最终导致这些部位发生癌症。如能早期发现，可以有效进行手术切除。但是如果癌细胞扩散入血液，则手术效果不佳。癌症细胞进入血液后，在一种称为MUC1的蛋白质的防护屏蔽作用下，最终被人体免疫系统破坏。细胞表面的MUC1可以防止癌细胞粘附在血管壁。
研究人员现在明确了这一屏障是如何崩溃并使癌症扩散。他们发现了一种小蛋白质即半乳糖凝集素3可以攻击MUC1并破坏其保护性屏蔽，使癌细胞暴露面积增大，这些暴露部位使癌细胞粘附于血管壁，随后穿透血管壁并形成转移灶。
癌细胞附着于血管壁是癌症扩散的关键步骤之一。人们早就知道，癌症患者血液中半乳糖凝集素3水平较正常人明显升高，但一直未曾明确这一变化与癌症扩散是否有关。研究人员称，半乳糖凝集素3作用非常重要，这将有助于未来癌症治疗新药的开发。
原文出处：
Scientists Discover How Body Fights to Control Spread of Cancer
01/08/07 -- Scientists at the University of Liverpool have found how two molecules fight in the blood to control the spread of cancer cells.
Researchers discovered that a large protein, which forms a protective shield around cancer cells and prevents them from causing secondary tumours, is attacked by a small protein that exists in the blood.
In diseases such as breast, lung and colorectal cancer, infected cells lose growth control and eventually form tumours at these sites. If caught early these tumours can be effectively removed surgically. However, when the cancer cells have invaded the blood, the effectiveness of surgery is reduced.
Cancerous cells that have entered the blood, however, are still prevented from causing further disease by the protective shield of a protein called MUC1 in which the cancerous cells are eventually destroyed by our immune system. Scientists have now discovered how this protective shield is broken down, allowing cancer to spread throughout the body.
Dr Lu-Gang Yu, from the University's School of Clinical Sciences, explains: "MUC1 on the cell surface prevents the cancer cells from attaching to the blood vessel wall which causes secondary tumours. We have discovered that a small protein called galectin-3, attacks MUC1 and breaks up its protective shield, forcing large areas of the cancer cell to become exposed. The exposed areas of the cell allow the cancer to attach to the blood vessel wall. The cancer cells then eventually penetrate the blood wall to form tumours at secondary sites.
"The attachment of cancer cells to the blood vessel wall is one of the key steps in the spread of cancer. It has been known for a few years that galectin-3 concentration is significantly higher in the blood of cancer patients than in healthy people but until now scientists did not know whether this increase played any role in the spread of cancer. Our study indicates that galectin-3 may play a critical role and may have significant implications for future developments of drugs for the treatment of the disease."
Source: University of Liverpool
相关基因：
MUC1
Official Symbol: MUC1 and Name: mucin 1, cell surface associated [Homo sapiens]
Other Aliases: CD227, EMA, H23AG, MAM6, PEM, PEMT, PUM
Other Designations: DF3 antigen; H23 antigen; MUC-1/SEC; MUC-1/X; MUC-1/Y; MUC-1/Z; MUC1/ZD; breast carcinoma-associated antigen DF3; episialin; epithelial membrane antigen; epithelial mucin tandem repeat sequence; mucin 1; mucin 1, transmembrane; peanut-reactive urinary mucin; polymorphic epithelial mucin; tumor associated epithelial mucin; tumor mucin antigen
Chromosome: 1; Location: 1q21
MIM: 158340
GeneID: 4582
