Researchers at the University of Pittsburg School of Medicine have successfully removed liver and prostate cancer fusion genes using the CRISPR-Cas9 gene editing tool.
Fusion genes are often associated with cancer. They involve two separate genes fusing, resulting in the synthesis of abnormal cancer-promoting proteins.
The researchers had previously identified a panel of fusion genes that were involved in recurrent, aggressive forms of prostate cancer. One of those genes, called MAN2A1-FER, was discovered to be responsible for rapid tumor growth in several other forms of cancer in the liver, lungs and ovaries.
The team targeted this DNA sequence using CRISPR-Cas9 and successfully removed the fusion genes in mice, replacing them with a gene that helps defeat cancer cells.
CRISPR-Cas9 can be used to make highly specific gene edits, and since the fusion genes are only present in cancer cells, the researchers were able to make the edits without any adverse effects.
The mice used for the study had received transplants of human liver and prostate cancer cells. The humanized mouse models showed no metastasis during the 8 weeks following CRISPR-Cas9 treatment and tumors reduced in size by up to 30%. In the control group, tumors increased almost 40-fold in size over the same period and many of the tumors metastasized. In all cases, control group mice died before the end of the study.
The lead author of the study, Jian-Hua Luo, M.D., Ph.D., professor of pathology at the University of Pittsburg School of Medicine and director of its High Throughput Genome Center, said “Other types of cancer treatments target the foot soldiers of the army. Our approach is to target the command center, so there is no chance for the enemy’s soldiers to regroup in the battlefield for a comeback.”
This study only demonstrated partial reduction in tumor size, although it was possible to greatly improved survival rates. The researchers are now planning to test their strategy to determine whether it is possible to completely eradicate the disease.
The study was published in the Journal Nature Biotechnology on May 1, 2017.