PTX-2

Suicide Genes Kill Cancer

By Kim Tae-gyu
Staff Reporter

Shin Deug-yong
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 yesterday 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.