Breast cancer vaccine; organs from pigs; vitamin D
December 1, 2021 | View PDF
A breast cancer vaccine is becoming a step closer to reality. Researchers at the Cleveland Clinic are studying a vaccine for preventing triple-negative breast cancer, the most aggressive and lethal form of the disease. Currently, the researchers are conducting a phase I trial to determine the maximum tolerated dose of the vaccine in women with early-stage triple-negative breast cancer.
The U.S. Food and Drug Administration (FDA) recently approved an investigational new drug application for the vaccine, which permits Cleveland Clinic and partner Anixa Biosciences, Inc. to start the study.
“We are hopeful that this research will lead to more advanced trials to determine the effectiveness of the vaccine against this highly aggressive type of breast cancer,” said study principal investigator Dr. G. Thomas Budd of Cleveland Clinic’s Taussig Cancer Institute, Cleveland, Ohio. “Long-term, we are hoping that this can be a true preventive vaccine that would be administered to healthy women to prevent them from developing triple-negative breast cancer, the form of breast cancer for which we have the least effective treatments,” he said.
Triple-negative breast cancer accounts for a disproportionately higher percentage of breast cancer deaths and has a higher rate of recurrence. This form of breast cancer is twice as likely to occur in African-American women, and approximately 70% to 80% of the breast tumors that occur in women with mutations in the BRCA1 genes are triple-negative breast cancer.
“This vaccine approach represents a potential new way to control breast cancer,” said Vincent Tuohy, who is the primary inventor of the vaccine and a staff immunologist at Cleveland Clinic’s Lerner Research Institute. The investigational vaccine targets a breast-specific lactation protein, a-lactalbumin, which is no longer found post-lactation in normal tissues, but is present in the majority of triple-negative breast cancers. Activating the immune system against this “retired” protein provides pre-emptive immune protection against emerging breast tumors that express a-lactalbumin. The vaccine also contains an adjuvant that activates an innate immune response that allows the immune system to mount a response against emerging tumors to prevent them from growing.
“This vaccine strategy has the potential to be applied to other tumor types,” explained Tuohy. “Our translational research program focuses on developing vaccines that prevent diseases we confront with age, like breast, ovarian and endometrial cancers. If successful, these vaccines have the potential to transform the way we control adult-onset cancers and enhance life expectancy in a manner similar to the impact that the childhood vaccination program has had.”
Xenotransplantation opens door to new supply of organs
It may soon be possible to grow organs in pigs and transplant them in individuals needing organ transplants. The first investigational transplantation of a genetically engineered, nonhuman kidney to a human body was recently completed at NYU Langone Health, marking a major step forward in potentially utilizing an alternative supply of organs for people facing life-threatening diseases.
Known as xenotransplantation, the kidney was obtained from a genetically engineered pig hundreds of miles away and transplanted into a deceased donor who was maintained on a ventilator, with the consent of the family, for 54 hours while the function and acceptance of the new kidney was studied.
The gene that encodes the glycan known as alpha-gal, which is responsible for a rapid antibody-mediated rejection of pig organs by humans, was “knocked out” in the donor pig. The pig’s thymus gland, which is responsible for “educating” the immune system, was transplanted with the kidney to stave off novel immune responses to the pig kidney.
Whole body donation after death for the purpose of breakthrough studies represents a new pathway that allows an individual’s altruism to be realized after brain death declaration in circumstances in which their organs or tissues are not suitable for transplantation.
According to data compiled by the Organ Procurement and Transplantation Network of the U.S. Department of Health and Human Services, there are more than 90,000 people awaiting a life-saving kidney transplant in the U.S. and more than 32,000 people have been added to the national kidney wait list year to date.
“This is a transformative moment in organ transplantation,” said Dr. Robert Montgomery, who is a Professor and chair of the Department of Surgery at NYU Langone, New York, New York. “The medical and scientific communities have been working toward xenotransplantation to sustain human life for more than 50 years. There have been many hurdles along the way, but our most recent procedure significantly moves these endeavors forward.”
This research now provides new hope for an unlimited supply of organs, a potential game-changer for the field of transplantation and those now dying for want of an organ, according to Dr. Montgomery.
Know your vitamin D levels
All the staying home during the pandemic has left many more people vitamin D deficient and some researchers now refer to vitamin D deficiency as an “invisible epidemic.” Vitamin D deficiency is already extremely common, affecting approximately 42% of the U.S. population, according to research published in the National Institutes of Health database.
Doctors ranging from orthopedic surgeons to family medicine practitioners are seeing an uptick in patients with vitamin D deficiency. More testing, people staying indoors because of skin cancer risk, and safety precautions during the COVID-19 pandemic, have been factors in the increase.
Although most people have no symptoms, severe cases of vitamin D deficiency can lead to thin, brittle, or misshapen bones. The deficiency is highest among older adults, and individuals who are institutionalized or hospitalized, according to a study published in Pharmacotherapy. It found that 60% of nursing home residents were low in vitamin D. A separate study in The New England Journal of Medicine found that 57% of hospitalized patients were vitamin D deficient.
“As you get older, bone resorption increases and bone formation decreases, so if you don’t substitute that loss with enough calcium, it causes a bone mass deficiency,” said Dr. Deepa Iyengar, who is a professor of family and community medicine at UTHealth in Houston, Texas. “Your body thinks you’re short of vitamin D, so it takes that vitamin from the bone and gives it to the blood, which puts people at major risk for osteoporosis.”
Vitamin D production in the skin from sunlight exposure also declines with advancing age, making older adults more dependent on the dietary supplements. A person can get vitamin D in three ways: through the skin, from their diet, and from medically prescribed supplements. A few foods, including fatty fish, beef liver, cheese, mushrooms and egg yolks, naturally carry the nutrient. It can also be found in fortified foods and beverages such as milk, breakfast cereals, orange juice, yogurt and soy drinks.
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute. He can be reached at email@example.com.