Suicide genes kill cancer

Suicide genes kill cancer

July 8, 2005

A team of South Korean scientists developed a breakthrough method to tackle nature's most-feared killer, cancer, via suicide genes that selectively destroy cancerous cells.

The team, led by Dankook University professor Shin Deug-yong, said on June 21 that it found a substance called PTX-2, which causes cancer cells to kill themselves. "PTX-2 attenuates a protein named actin. When actin weakens, cancer cells without p53, tumor-suppressing genes, stress out and commit suicide while leaving normal cells alone," the 46-year-old said.

About half of all cancer patients have tumor cells lacking p53, so Shin said that theoretically, PTX-2 should remove cancer cells without causing side effects because it doesn't affect normal cells. "In experiments using mice last year, we confirmed that PTX-2 kill cancer cells. We hope this substance takes us one step closer to ending the war against cancer," Kim said.

During the lifetime of a cell, its DNA suffers constant damage via both normal metabolic activities and environmental factors, including smoking or radiation. These might cause structural problems to the DNA molecule and change the way a cell reads information encoded in its genes, posing a serious threat to the human body.

To straighten things up, the body has a two-step self-repair mechanism. The first is a DNA repair system, which remedies the damage. But some cells survive the repairs and acquire further mutations.

As second-phase protection, bodies use the last resort, called apoptosis, in which irreparably damaged DNA commits suicide as it is programmed to do to prevent the occurrence of cancer.

PTX-2 causes some of the cancer cells to destroy themselves even after the strains wither the self-repair.

Kim's team applied for a domestic patent for its findings, which were featured in the latest edition of Oncogene, the British-based cancer research journal.