International breakthrough discovery in research! Deching Chang, Professor of Biomedical Sciences Department from National Chung Cheng University develops gene therapy vector to effectively enhance the prostate cancer treatment

Published on Aug 12 2019

Prostate cancer is the second most deadly cancer discovered in men in the world and the fifth commonly occurred cancer to males in Taiwan. So far, the status of patients with advanced prostate cancer treated by hormonal therapy is often turned into hormone-resistant, making the condition more difficult to be controlled and causing the mortality rate to increase. Chang, Deching, a professor of the Department of Biomedical Sciences at National Chung Cheng University (CCU), recently succeeded in using particles that mimic the structural protein of human polyomavirus as the gene therapy vectors to help lock attack on prostate cancer cells during the treatment, and to suppress the tumor growth effectively. These important research findings have attracted extensive attention internationally and been published in the top journals on gene therapy.

In addition to the traditional surgery, radiation therapy, chemotherapy, and hormonal therapy are other common practices to treat prostate cancer. "Owing to Androgen (male hormone) can induce the prostate cancer, the hormone therapy uses anti-androgen drugs or other methods to stop male hormones taking effect on the cancer cells, so can the cancerous condition be under control." Professor Chang said. Unfortunately, by the time when the patient's condition eventually progresses to Castration-resistant prostate cancer (CRPC) which indicates that the cancer cells have mutated and developed into resistant stage against hormonal treatment, the chance to control the condition will be even slimmer. Therefore, in search for a new way to deal with prostate cancer now becomes critically important.

With his 30 year-experience dedicating to the research of the JC virus, one of the two human polyomavirus, Professor Chang has produced the JCV-capsid-like particles (a protein similar to one of the JC capsid proteins) through the bacteria, Escherichia coli (E. coli), as carriers for the gene therapy. Chang explained that gene therapy often uses the specificity of certain virus to transfer genes with therapeutic function to the targeted problematic tissue cells. However, once the carrier enters the human body, it is just like setting out a little boat into the sea. "How to direct the carrier to a specific place is the difficult part of gene therapy."

Consequently, CCU research team transformed the "suicide gene" into the JCV-capsid-like particles to do the job. Chang further expressed that, prostate cancer development usually comes with excessively expressed prostate specific antigen (PSA), which are later utilized to clone the suicide genes. Since the suicide genes only works on prostate cancer cells, and it does not harm other normal cells, so during the treatment, when the JCV-capsid-like particles reach the prostate tumor, the suicide genes can be activated to attack the tumor cells specifically.

At present, this method has been found effective to suppress the growth of cancer cells through animal experimentation. This technology can not only make up the failure of hormone therapy, but also be used in the early treatment of prostate cancer. This research results have been published in the internationally renowned journal《Cancer Gene Therapy》recently. In addition, Professor claimed that the JCV-capsid-like particles can be easily mass-produced in E. coli and the source of E. coli is low-cost and easy to obtain, so the production will be resonablly cost-effective. More, the JCV-capsid-like particles do not contain any genes of real JC virus, thus will not lead to viral diseases, it is fairly safe for internal application.

In the future, Professor Chang will conduct more variables research through animal experimentation, then apply for clinical trials. In addition to the specificity of suicide genes, Chang expects to create a special marker on the JCV-capsid-like particles, hoping to help the particles identify the prostate cancer cells faster, to enhance the success rate of the treatment. "So far, there is an 80% possibility of metastasis that the cancer development may extend from prostate to bones!" Despite that, Chang again mentioned that his team has been doing cooperated research with the urology department of Chiayi Christian Hospital for a long time and currently, the gene therapy exercised on patient by the doctors in the hospital, using the JCV-capsid-like particles to treat bone metastasis, has achieved its initial results. The future of a better prostate cancer treatment is positive.