Peking University, Nov. 30, 2011: Nature Communications published professor Xi Jianzhongand his team’s discovery of metastasis suppressor gene on November 22. Professor Xi is from College of Engineering, Peking University (PKU). By high-throughput screening techniques, the team made genomics analysis of miRNA for various types of cancer and confirmed miRNA’s broad participation in the regulation of cancer metastasis, in the process finding out miR-23b, a multi-directional metastasis suppressor gene.

In recent years, as cancer research proceeds, the miRNA has drawn worldwide attention in the field of cancer biotherapy. MiRNAs are endogenous single-stranded RNA molecules of about 19 to 24 nucleotides in length, highly conservative in the process of evolution, and able to induce the target gene mRNA’s degradation or to suppress its translation through special base-pairing with it. In this way they are capable of controlling the target gene’s expression on a broader scale. So far, more than 1,000 kinds of miRNA have been discovered, and it is predicted that they can control 1/3 of the gene expression within a human body. Although it has been confirmed that some miRNAs’ expressional imbalance may activate relevant cancer genes’ expression or lead to cancers by inducing a lack of the cancer suppressor gene, there is still room for scientists to explore in miRNAs’s role in cancer therapy.

Professor Xi and his team invented a new kind of self-assembled cell microarray that systematically evaluated human bodies’ miRNAs’ influence on cancer cells’ actions such as migration and invasion. The research confirmed miRNAs’ broad participation in cancer metastasis–among all kinds of cancer cells, more than 20% miRNAs play a controller’s role in cell migration. Researchers also found out miR-23b, an important gene of multi-directional metastasis suppression—its expression in samples of human colorectal cancer was apparently low; moreover, it was able to inhibit several signaling molecules such as FZD7 and MAP3k1 through targeting. MiR-23b is important in the negative regulation of cancer migration processes such as tumor’s growth, migration and the growth of artery.

Professor Xi’s research provides a new understanding of the miRNA’s role in cancer’s occurrence and development in addition to a latent target for the prevention and diagnosis of cancer migration, and it gives another direction for the biotherapy of cancer. The research was funded by National Natural Science Foundation of China, Ministry of Science and Technology, etc.

Written by: Zhao Ning
Edited by: Liu Lu
Source: PKU News (Chinese)