Tumor Resistant Mice Point To Novel Cancer Treatments

Researchers have established that white blood cells, derived from immune mice, have an innate immunity against cancer, which can be exploited in the development of novel forms of cancer treatment. When such cells were introduced into other mice with cancer, it was found to confer a lifelong immunity against the much-dreaded disease.

This study for the first time highlights the presence of a biological pathway in a specific species. Previous studies had suggested a similar link in humans as well, that could be harnessed to arrive at a novel approach for cancer treatment.

‘The idea of cells being able to kill tumor cells ... is very exciting. But this is a mouse, and there is no guarantee that the same gene will exist in people,’ said biologist Howard Young of the National Cancer Institute's Center for Cancer Research.

’This is a truly remarkable phenomenon ... and it really needs confirmation from other institutions," said Dr. Zhen Cui of Wake Forest. The limited availability of these special mice ensures that the above results have not been reported by any another lab or research organisation. The results of this interesting study have been published in the Proceedings of the National Academy of Science.

The researchers are said to have ended up with the remarkable immune mice by accident, in the year 1999. The researchers initial studies were targeted at identifying biological mechanisms behind the spread of cancer.

As a part of this study, highly virulent cancer cells were introduced into mice. Surprisingly, one of the mice injected with cancer cells had not developed any tumor. This effect was seen even when the animal was injected with tumor cells, approximating to 10% of its body weight.

Out of curiosity, the researchers bread the mouse, only to find that 50% of its offspring had the same kind of tumor resistance. Cross breeding experiments were also taken up. The researchers upon analysis found that white blood cells of the tumor resistant mice induced a killing process called cytolysis. A combination of WBCs (neutrophils, macrophages and natural killer cells) from the special mice was then injected into mice with tumors.

As expected, these injected cells were found to destroy the tumor, even the most aggressive forms. More importantly the healthy tissue was unaffected and normal mice with tumors developed a life long immunity against tumors.

‘This is the first report of a novel [treatment] mechanism. The two most dramatic things are: one, that the response itself is outstanding, and two, the fact that they looked at a variety of different cell lines and found the activity was there for all of them, said Dr. Andrew Raubitschek, a cancer immunologist at the City of Hope National Medical Center in Duarte.

‘This deserves intensive follow-up. Cui's papers are technically sound, carefully controlled and well thought out. But whenever there is a result this surprising, it's always important to have others confirm it,’ concluded Dr. Richard Miller of the University of Michigan Medical School.