By Kim Hyun-cheol
Staff Reporter
A team of Korean scientists has found a new mechanism that can inhibit the growth of colon cancer, the Ministry of Education, Science and Technology said Sunday.
Headed by professors Kim Keun-il of Sookmyung Women's University and Baek Sung-hee of Seoul National University, the molecular biologists' team published an article describing how a certain nuclear receptor in an interactive process with proteins, called transrepression, regulates cell proliferation and tumor progression in human colon cancer.
Nuclear receptors, a class of proteins found within the interior of cells, are responsible for sensing certain kinds of other molecules.
They interact with other proteins to regulate the expression of specific genes, controlling various vital functions in organisms such as homeostasis and metabolism.
The article describing the study was published in the latest edition of Molecular Cell journal, an affiliate publication of Cell, one of the world's most cited scientific journals.
The study was aimed at clarifying the mechanism of the Wnt signaling pathway ― a network of proteins in a cell that converts one kind of signal or stimulus into another ― which is thought to play diverse roles in the occurrence of cancer stem cells
The underlying mechanism of this antagonism, however, has been poorly understood up to date. In this study, the receptor combined with the beta-catenin protein in the pathway in order to perform its function.
The research team found the retinoic acid in the orphan nuclear receptor alpha (RORα) in the biological pathway can suppress progression in cancer by phosphorylatation, the addition of a phosphate group to a protein or another organic molecule.
RORα is related to speciation in the cerebellum, the part of the brain that plays a key role in motor control. Its specific role in cancer-related mechanisms had not been revealed before the study.
The team analyzed normal and cancer tissue samples collected from colon cancer patients, and found RORα phosphorylatation was reduced in cancer cells by more than 70 percent.
This is a meaningful consequence because it shows the mechanism can be applied as a future diagnostic criterion.
It also uncovered the long-standing riddle of the role of protein kinase C, which has been believed to work as an inhibitor of colon cancer, by revealing that the enzyme activation is involved in RORα phosphorylatation.
Based on the studies, the team has filed for domestic and international patents for an anti-cancer peptide sequence.