As October and National Breast Cancer Awareness month are quickly approaching, a new study by The University of Texas MD Anderson Cancer Center recently reported results from a gene therapy study that has shown to cause breast cancer cells to self-destruct, to lower the chance of recurrence, and to help increase the effectiveness of some types of chemotherapy. Though the common chemotherapy drugs such as Lapatinib, Paclitaxel, Doxorubicin and Cisplatin can stabilize the level of the cancerous stem cells there currently are not any drugs commercially available to reduce them. “This research suggests a potential therapeutic approach to breast cancer stem cells that will minimize recurrence and drug resistance,” says Mien-Chie Hung, Ph.D., vice president for basic research, professor and chair of MD Anderson’s Department of Molecular Cellular Onocology. Breast cancer stem cells are often resistant to chemotherapy and radiotherapy and are major obstacle for breast cancer treatment. If any of the cancer stem cells remain after treatment, a new tumor often forms.
How Did They Do It?
Using an innovative delivery system created at MD Anderson called VISA, short for versatile expression vector, the gene therapy is delivered intravenously in a liposome. The liposome contains a promoter, two components that boost gene expression in the target tissue and also includes a payload, in this case a mutant gene called BikDD known to kill cancer cells. Not only has this delivery system been used for treating breast cancer but has also been applied in lung, liver, ovarian, and pancreatic cancer preclinical models. In terms of pancreatic cancer, MD Anderson clinical researchers are preparing a Phase I clinical trial.
The proteins of the Bcl-2 family are the essential proteins that increase the chance for breast cancer tumor growth and resistance. A high concentration of these proteins aid in poor prognosis and a higher chance of resistance to chemotherapy. However, in this recent study when researchers for MD Anderson delivered the BikDD gene using the VISA delivery method the results showed that the Bcl-2 proteins were blocked, which eliminated the stem cells.
What about Tumor Growth?
In a study using mice researchers were able to reduce tumor volume by 75 percent using a VISA that contained claudin4. Claudin4 is a protein that is over-expressed in breast cancer and was used as a targeting agent to express BikDD in the breast cancer cells. This process silenced the Bcl-2 proteins and allowed the cancer cells to self-destruct. Another note able quality of the process is that since the VISA targeted the BikDD gene on only the cancer cells, normal cells were not affected. “VISA-claudin4-BikDD gene therapy may provide an effective strategy to inhibit breast tumor growth,” says Dr. Hung. “It demonstrates virtually no toxicity in normal cells and produces a profound killing effect in multiple breast cancer cell lines and synergy with other agents.” The next step is to move VISA-claudin4-BikDD into a Phase 1 clinical trial to test its effect on patients with breast cancer.
How Can You Help?
Every 68 seconds, somewhere in the world, a woman dies from breast cancer – the most prevalent cancer among women today.
Women in the United States get breast cancer more than any other type of cancer except for skin cancer. It is second only to lung cancer as a cause of cancer death in women.
Each year it is estimated that nearly 200,000 women will be diagnosed with breast cancer and more than 40,000 will die. Approximately 1,700 men will also be diagnosed with breast cancer and 450 will die each year. The evaluation of men with breast masses is similar to that in women, including mammography.
You can support the study of breast cancer and those affected by donating here: