A research team in the Department of Molecular Biology, Pyongyang Medical College,
It is now clear that all the tumorigenesis is influenced by the activation or inactivation of cancer related genes. And recently cancer research focus is the promoter methylation of tumor suppressor genes which leads to the inactivation of them. Many of them acknowledge that methylation in CpG island of promoter region of tumor suppressor genes are the early events in cancergenesis and strongly associated with the development of cancer. Therefore, methylation detection in individuals would contribute to the diagnosis in cancer as well as other genetic conditions.
Now in many countries, methylation detection procedures like MS-PCR, various kit agents, Microarray are used in methylation status detection of many tumor suppressor genes and research for further application to clinic.
In colorectal cancer, methylation rate in tumor suppressor genes differ each genes and there is almost no gene whose promoter methylation rate is significantly higher.
We used MS-PCR for HPP1 gene by isolating genomic DNA from various samples such as tissue, serum, feces from colorectal cancer patients. Methylation rate of HPP1 from tissue, serum, feces were 92.3%, 83.8%, 86.8% respectively but there was no significant differences between them. In contrast, there was no methylation detected in HPP1 promoter region from normal controls. And there was no correlation between methylation status in tissue of colorectal cancer patients and certain demographic features like gender, age, family history, tumor size.
Next, there were no correlation between HPP1 promoter methylation status and clinic-pathological features like, cancer stages, differentiation degree and histotype, either.
Thus, we concluded that HPP1 promoter methylation status could be strong indicator for colorectal cancer diagnosis. We are continuing to investigate the methylation status of several tumor suppressor genes in breast cancer and uterus cancer.
