美国宾州著名的 Kimmel癌症研究中心(Kimmel Cancer Center) ，发展出一种新的方法，可以在体外大量的产生血液里的自然杀手细胞，然后搭配一项以抗癌单株抗体为主的癌症治疗策略，居然大幅的增加了抗癌药物的作用。
主导这份研究计划的 Takami Sato医师，在四月份美国洛杉矶举行的全美癌症研究学会 (American Association for Cancer Research)年会中表示，目前实验室里的数据，证实把这种体外增殖成功的自然杀手细胞，和一个专一性辨识称 HER2/neu蛋白质的单株抗体加在一起，可以有效的阻杀乳癌 (breast cancers)细胞的增生。
先前的临床分析数据证实，大约在四分之一的临床乳癌检体中，可以发现 HER2/neu蛋白质有异常活化的现象。
Sato 博士进一步解释表示，自然杀手细胞在身体里，本来就具有毒杀肿瘤细胞的能力，不过一般来说，罹患癌症的病人，其体内的自然杀手细胞的浓度，都会有下降的迹象，而剩余下来的杀手细胞，也可能存在着辨识力不足的可能，如今如果可以在体外大量的增生杀手细胞，再搭配原本具有专一性辨识，称为Herceptin 的单株抗体，那等于强化了自然杀手细胞的作用， 失序的癌细胞当然逃不过这样的治疗策略。
(资料来源 : Bio.com)
英文原文：
Jefferson Researchers Boost Immune 'Killer Cells,' Increase Antibody Effectiveness Against Cancer
04/18/07 -- Researchers at the Kimmel Cancer Center at Jefferson in Philadelphia have devised a novel method to expand the number of immune system "natural killer (NK)" cells from blood cells outside the body. They have found that adding such cells to anti-cancer therapies involving monoclonal antibody drugs is more effective in killing cancer cells, and perhaps someday may improve treatments.
Reporting April 18, 2007 at the annual meeting of the American Association for Cancer Research in Los Angeles, scientists led by Takami Sato, M.D., K. Hasumi Associate Professor of Medical Oncology at Jefferson Medical College of Thomas Jefferson University showed in laboratory studies that adding such NK cells to a monoclonal antibody, Herceptin, which targets the HER2/neu protein on breast cancer cells, was more efficient at killing the cancer cells. The HER2/neu protein is expressed in approximately one-quarter of all breast cancers.
According to Dr. Sato, monoclonal antibodies help kill cancer cells by attaching to the cancer cell surface, in turn stimulating an outpouring of "effector" cells such as NK cells that attempt to neutralize the cancer. NK cells alone are often powerful cancer fighters, he notes, but NK cell function in cancer patients can be diminished, and chemotherapy can make things even worse.
Dr. Sato, international research study coordinator Mizue Terai, M.S., and their co-workers decided to try a different approach. They cultured peripheral blood mononuclear cells, which are a mixture of immune cells, including NK cells, for three weeks in the test tube with their novel technique. The resulting population of NK cells increased 500 to 1,000-fold. In subsequent experiments, they showed that the combination of NK cells and Herceptin was effective in killing HER2/neu-expressing breast cancer cells, though the effect depended on the amount of antibody.
They found that the expanded group of NK cells and antibody had little effect against breast cancer cells that did not express the HER2/neu protein.
"It [the results] doesn't mean that the antibody and the NK cells will cure the cancer," Dr. Sato notes, "but it shows that using an antibody that recognizes the cancer cell along with added NK cells can be very effective against the tumor."
The researchers also found that the monoclonal antibody Rituxan greatly enhanced the cancer cell-killing ability of the expanded NK cells against another cancer cell line, B-cell lymphoma cell line. Rituxan is typically used in combination with chemotherapy to treat patients with B-cell non-Hodgkin's lymphoma.
Dr. Sato says that the technique can be applied to "any cancer that has a monoclonal antibody available."
The team's next step is to test the effectiveness of the added NK cells in an animal model. The group is also in the process of starting an early phase clinical study.
Source: Thomas Jefferson University
