Medical Minutes
Gene therapy may help reverse blindness
Researchers are moving closer toward a novel gene therapy approach to restore vision to the blind. British researchers in a laboratory study have demonstrated how it might be possible to reverse blindness using gene therapy to reprogram cells at the back of the eye to become light sensitive.
Most causes of untreatable blindness occur due to loss of the millions of light sensitive photoreceptor cells that line the retina. However, the remaining retinal nerve cells, which are not light sensitive, remain in the eye. Samantha de Silva and colleagues at Oxford University used a viral vector to express a light sensitive protein (melanopsin) in the residual retinal cells in mice that were blind from retinitis pigmentosa, the most common cause of blindness in young people.
The mice were monitored for more than a year and they maintained vision during the entire time, being able to recognize objects in their environment, which indicated a high level of visual perception. The cells expressing melanopsin were able to respond to light and to send visual signals to the brain. The Oxford team has also been conducting a clinical trial with an electronic retina. This trial has been successful in blind patients. However, the genetic approach may have advantages because it would be so simple to administer.
The research was led by Professors Robert MacLaren and Mark Hankins at the Nuffield Laboratory of Ophthalmology in Oxford. “There are many blind patients in our clinics and the ability to give them some sight back with a relatively simple genetic procedure is very exciting. Our next step will be to start a clinical trial to assess this in patients,” said lead study author Samantha de Silva.
A new era in the war on breast cancer
Thanks to new genomic testing there is now no more “one size fits all approach” when it comes to treating breast cancer. In the past five years, researchers have deciphered the genetic mutations driving most breast cancer and they now are targeting those specific mutations to cripple the cancer. Breast cancer is made up of several subtypes, and ideally each type should be treated with therapies that target the unique underlying biological problems.
For the past 25 years, long-term survival and cure rates have significantly improved for women with breast cancer. This is due in large part to the development of new drug therapies that target aggressive subtypes of breast cancer such as HER2-positive and ER positive breast cancers. Currently, targeted therapies are now available for approximately 85 percent of women diagnosed with breast cancer.
Dr. Sara Hurvitz, who is an associate professor of medicine, division of hematology and oncology at the David Geffen School of Medicine at UCLA in California, said that despite these successes there is still much more work to be done. One particularly aggressive subtype called triple negative breast cancer now comprises between 10 to 20 percent of all diagnosed breast cancers, and it is challenging to treat.
Important risk factors for breast cancer include family history of the disease, and inherited changes or mutations to certain genes, such as BRCA1 and BRCA2. While these are risk factors for breast cancer that cannot be controlled, there are risk factors a woman can control. These include maintaining a healthy weight, being physically active and limiting alcohol consumption.
Researchers around the world are working to find better ways to prevent, detect and treat breast cancer, and to improve the quality of life of patients and survivors. In just the past five years, major advances have occurred.
Olives and olive oil may help prevent diabetes
Biochemists at Virginia Tech have been dipping into the health benefits of olives and olive oil and discovered that the olive-derived compound oleuropein appears to help prevent the onset of type 2 diabetes. The health benefits of olives and associated natural products such as olive oil have long been recognized and touted by proponents of the Mediterranean diet. However, until now little has been known about what specific compounds and biochemical interactions in the fruit contribute to its medical benefits. It is believed to produce benefits in terms of weight loss and prevention of type 2 diabetes.
The investigators discovered that the olive-derived compound oleuropein helps the body secrete more insulin, a central signaling molecule in the body that controls metabolism. The same compound also detoxifies another signaling molecule called amylin, which increases production and forms harmful
aggregates in type 2 diabetes. In these two distinct ways, oleuropein appears to help prevent the onset of type 2 diabetes.
The findings, which were recently published in the journal Biochemistry, could help improve understanding of the scientific basis of health benefits of olive products and develop new, low-cost nutraceutical strategies to fight type 2 diabetes and related obesity.
“Our work provides new mechanistic insights into the long-standing question of why olive products can be anti- diabetic,” said lead study author Bin Xu, who is an assistant professor of biochemistry in the College of Agriculture and Life Sciences at Virginia Tech. “We believe it will not only contribute to the biochemistry of the functions of the olive component oleuropein, but also have an impact on the general public to pay more attention to olive products in light of the current diabetes epidemic.”
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute. He can be reached at medicalminutes@gmail.com.
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute.
