S. Korean scientists find colon cancer-inhibiting gene

SEOUL, Jan. 31 (Yonhap) -- South Korean scientists said Sunday that they have
discovered a receptor gene that can inhibit the growth of colon cancer in humans
and lead to new treatment methods down the road.
The team led by Baek Sung-hee, a professor of biological sciences at Seoul
National University, and Kim Keun-il, a biology professor at Sookmyung Women's
University, found evidence that the retinoid-related orphan receptor alpha (ROR
alpha) phosphorylation can affect tumor growth.
The discovery published in the latest issue of U.S.-based Molecullar Cell is
significant because it has the potential to be developed into a treatment for
colon cancer and provide doctors with a detection marker to diagnosis the disease
quickly.
In the past, ROR alpha -- discovered some 30 years ago -- were known only to
cause problems for the cerebellum or little brain leading to muscular atrophy and
osteoporosis.
"An ROR alpha that undergoes the phosphorylation process causes disruption of
beta-catenin proteins, which leads to a suppression of the growth of colon
cancer," Baek said.
Phosphorylation occurs through the activation of the PKC enzymes in the "serine
amino acids" found in ROR alpha.
This correlation, said Baek, helps explain why PKC enzymes are active when there
is no malignant colon cancer tumor growth and becomes passive if a person is
suffering from the disease. This is a special case since in other types of
cancer, active PKC enzymes are a sign of cancer growth.
She said laboratory tests conducted on 30 colon cancer patients from a Seoul
hospital showed that there was a 70 percent decrease in phosphorylation of ROR
alpha in actual colon cancer growth.
"The percentage is very high and helps establish a strong link between ROR alphas
and tumors," the professor said, adding that because there is a good chance for
further development the team has applied for both domestic and international
patent protection.
She claimed that besides colon cancer, the latest discovery could help advance
research of other types of cancer and osteoporosis.
The Baek-Kim team received funding from the state-run National Research
Foundation of Korea with about 500 million won (US$430,800) being used to conduct
research over the last four years.
In the future, the team is expected to focus on further development of their
findings that could lead to a treatment of the disease.
yonngong@yna.co.kr
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