An international team of researchers has discovered what promises to be the on-off switch behind several major diseases.

High-dose injections of vitamin C, also known as ascorbate or ascorbic acid, reduced tumor weight and growth rate by about 50 percent in mouse models of brain, ovarian, and pancreatic cancers, researchers from the National Institutes of Health (NIH) report in the August 5, 2008, issue of the Proceedings of the National Academy of Sciences.

A blue curing light used to harden dental fillings also may stunt tumor growth, Medical College of Georgia researchers say.

Immune cells called macrophages can destroy tumor cells by producing inflammatory proteins that are toxic to the tumor. But the environment inside the tumor somehow halts this production and instead causes the cells to make proteins that promote tumor growth.

The formation of new blood vessels, or angiogenesis, is an Achilles’ heel of tumor growth, because tumors depend on the supply of oxygen and nutrients for survival. Therefore, for some years now substances called angiogenesis inhibitors have been used in cancer treatment to suppress this process.

By increasing production of a blood pressure-regulating enzyme in mice, researchers have found they can enhance the mouse immune system's ability to sense tumor growth.

Targeting and killing the non-malignant cells that surround and support a cancer can stop tumor growth in mice, reports a research team based at the University of Chicago Medical Center in the March 1, 2008, issue of the journal Cancer Research. The discovery offers a new approach to treating cancers that are resistant to standard therapy.

Tumor growth has commonly been viewed as a result of mutations in a given cell that will therefore proliferate uncontrollably. However, a study conducted at the University of Helsinki, Finland, has demonstrated that in certain type of gastrointestinal polyps, the cause of tumor development are mutations in the smooth muscle cells, previously regarded as “innocent bystanders”.

Researchers at Johns Hopkins and Ohio State University have found that the number of copies of a particular gene can affect the severity of colon cancer in a mouse model. Publishing in the Jan. 3 issue of Nature, the research team describes how trisomy 21, or Down syndrome in humans, can repress tumor growth.

While investigating how the hormone orexin might control sleep and hunger, researchers at UT Southwestern Medical Center have discovered, to their surprise, that it activates a protein, HIF-1, long known to stimulate cancerous tumor growth.

Zinc, an important trace element for healthy growth and development, can be related to pancreatic cancer.

A diet low in carbohydrates may help stunt the growth of prostate tumors, according to a new study led by Duke Prostate Center researchers. The study, in mice, suggests that a reduction in insulin production possibly caused by fewer carbohydrates may stall tumor growth