Editor's Note: A team of researchers in Italy recently used artificial intelligence and machine learning to diagnose Alzheimer's disease on a brain scan an entire decade before symptoms show up in the patient. While some people argue that early detection is critical, others believe the knowledge would do more harm than good. LeapsMag invited contributors with opposite opinions to share their perspectives.
Alzheimer's doesn't run in my family. When my father was diagnosed at the age of 58, we looked at his familial history. Both his parents lived into their late 80's. All of their surviving siblings were similarly long-lived and none had had Alzheimer's or any related dementias. My dad had spent 20 years working for the United Nations in the 60's and 70's in Africa. He was convinced that the Alzheimer's had come from his time spent in dodgy mines where he was exposed without the proper protections to all kinds of chemical processes.
Maybe that was true. Maybe it wasn't. The theory that metals, particularly aluminum, is an environmental factor leading to Alzheimer's has been around for a while. It's mostly been debunked, but clearly something is causing this epidemic as the vast majority of the cases in the world today are age-related. But no one knows what the trigger is, nor are we close to knowing.
If my father had had the Alzheimer's gene, I would go get myself checked for it. If some new MRI were commercially available to scan my brain and let me know if I was developing Alzheimer's, I would also take that test. There are four reasons why.
First, studies have shown that lifestyle has a major impact on the disease. I already run three miles a day. I eat relatively healthily. But like anyone, I don't live strictly on boiled chicken and broccoli. And I definitely enjoy a glass of wine or two. If I knew I had a propensity for the disease, or was developing it, I would be more diligent. I would eat my broccoli and cut out my wine. Life would be less fun, but I'd get more life and that's what's important.
The last picture taken of the author with her father before his death, in 2015.
Secondly, I would also have time to create an end-of-life plan the way my father did not. He told me repeatedly early on in his diagnosis that he did not want to live when he no longer knew me, when he became a burden, when he couldn't feed or bathe himself. I did my best in his final years to help him die quicker: I know that was what he wanted. But, given U.S. laws, all that meant was taking him off his heart and stroke medications and letting him eat anything he wanted, no matter how unhealthy. Knowing what's to come, having seen him go through it, I might consider moving to Belgium, which has begun to allow assisted suicide of those living with Alzheimer's and dementia if they can clearly state their intentions early on in the disease when they still have clarity of mind.
Next, I could help. Right now, there are dozens of Alzheimer's and dementia studies in the works. They are short thousands of willing test subjects. One of the top barriers to learning what's triggering the disease, and finding a cure, is populating these studies. So, knowing would make me a stronger candidate and would potentially help others down the road.
Finally, it would change my priorities. My father died the longest death possible: he succumbed last year more than 15 years after his diagnosis. My mother died the quickest possible way: she had a stress-related brain aneurysm 10 years after my father's diagnosis. Caring for him was too much for her and aneurysms ran in her family; her mother died of one as well. I already get a scan once every five years to see if I'm developing a brain aneurysm. If I am, odds are only 66% that they can operate on it—some aneurysms develop much too deep in the brain to operate, like my mother's.
Would she have wanted to know? Even though the aneurysm in her case was inoperable? I'm not sure. But I imagine if she had known, she would've lived her final years differently. She might have taken that trip to Alaska that she debated but thought was too expensive. She might have gotten organized earlier to make out a will so I wasn't left with chaos in the wake of her death; we'd planned for my father's death, knowing he was ill, but not my mother's. And she might have finally gotten around to dictating her story to me, as she'd always promised me she would when she found the time.
Telling my father's story at the end of his life helped his care.
With my startup MemoryWell, I spend my life now collecting senior stories before they are lost, in part because telling my father's story at the end of his life helped his care. But it's also in part for the story I lost with my mother.
If I knew that my time was limited, I'd not worry so much about saving for retirement. I'd make progress on my bucket list: hike Machu Picchu, scuba dive the Maldives, or raft the Grand Canyon. I'd tell my loved ones as much as I can in my time remaining how much they mean to me. And I would spend more time writing my own story to pass it down—finally finishing the book I've been working on. Maybe it's the writer in me, or maybe it's that I don't have kids of my own yet to carry on a legacy, but I'd want my story to be known, to have others learn from my experiences. And that's the biggest gift knowing would give me.
Editor's Note: Consider the other side of the argument here.
In November 2020, messenger RNA catapulted into the public consciousness when the first COVID-19 vaccines were authorized for emergency use. Around the same time, an equally groundbreaking yet relatively unheralded application of mRNA technology was taking place at a London hospital.
Over the past two decades, there's been increasing interest in harnessing mRNA — molecules present in all of our cells that act like digital tape recorders, copying instructions from DNA in the cell nucleus and carrying them to the protein-making structures — to create a whole new class of therapeutics.
Scientists realized that artificial mRNA, designed in the lab, could be used to instruct our cells to produce certain antibodies, turning our bodies into vaccine-making factories, or to recognize and attack tumors. More recently, researchers recognized that mRNA could also be used to make another groundbreaking technology far more accessible to more patients: gene editing. The gene-editing tool CRISPR has generated plenty of hype for its potential to cure inherited diseases. But delivering CRISPR to the body is complicated and costly.
"Most gene editing involves taking cells out of the patient, treating them and then giving them back, which is an extremely expensive process," explains Drew Weissman, professor of medicine at the University of Pennsylvania, who was involved in developing the mRNA technology behind the COVID-19 vaccines.
But last November, a Massachusetts-based biotech company called Intellia Therapeutics showed it was possible to use mRNA to make the CRISPR system inside the body, eliminating the need to extract cells out of the body and edit them in a lab. Just as mRNA can instruct our cells to produce antibodies against a viral infection, it can also teach them to produce the two molecular components that make up CRISPR — a guide molecule and a cutting protein — to snip out a problem gene.
"The pandemic has really shown that not only are mRNA approaches viable, they could in certain circumstances be vastly superior to more traditional technologies."
In Intellia's London-based clinical trial, the company applied this for the first time in a patient with a rare inherited liver disease known as hereditary transthyretin amyloidosis with polyneuropathy. The disease causes a toxic protein to build up in a person's organs and is typically fatal. In a company press release, Intellia's president and CEO John Leonard swiftly declared that its mRNA-based CRISPR therapy could usher in a "new era of potential genome editing cures."
Weissman predicts that turning CRISPR into an affordable therapy will become the next major frontier for mRNA over the coming decade. His lab is currently working on an mRNA-based CRISPR treatment for sickle cell disease. More than 300,000 babies are born with sickle cell every year, mainly in lower income nations.
"There is a FDA-approved cure, but it involves taking the bone marrow out of the person, and then giving it back which is prohibitively expensive," he says. It also requires a patient to have a matched bone marrow done. "We give an intravenous injection of mRNA lipid nanoparticles that target CRISPR to the bone marrow stem cells in the patient, which is easy, and much less expensive."
Meanwhile, the overwhelming success of the COVID-19 vaccines has focused attention on other ways of using mRNA to bolster the immune system against threats ranging from other infectious diseases to cancer.
The practicality of mRNA vaccines – relatively small quantities are required to induce an antibody response – coupled with their adaptable design, mean companies like Moderna are now targeting pathogens like Zika, chikungunya and cytomegalovirus, or CMV, which previously considered commercially unviable for vaccine developers. This is because outbreaks have been relatively sporadic, and these viruses mainly affect people in low-income nations who can't afford to pay premium prices for a vaccine. But mRNA technology means that jabs could be produced on a flexible basis, when required, at relatively low cost.
Other scientists suggest that mRNA could even provide a means of developing a universal influenza vaccine, a goal that's long been the Holy Grail for vaccinologists around the world.
"The mRNA technology allows you to pick out bits of the virus that you want to induce immunity to," says Michael Mulqueen, vice president of business development at eTheRNA, a Belgium-based biotech that's developing mRNA-based vaccines for malaria and HIV, as well as various forms of cancer. "This means you can get the immune system primed to the bits of the virus that don't vary so much between strains. So you could actually have a single vaccine that protects against a whole raft of different variants of the same virus, offering more universal coverage."
Before mRNA became synonymous with vaccines, its biggest potential was for cancer treatments. BioNTech, the German biotech company that collaborated with Pfizer to develop the first authorized COVID-19 vaccine, was initially founded to utilize mRNA for personalized cancer treatments, and the company remains interested in cancers ranging from melanoma to breast cancer.
One of the major hurdles in treating cancer has been the fact that tumors can look very different from one person to the next. It's why conventional approaches, such as chemotherapy or radiation, don't work for every patient. But weaponizing mRNA against cancer primes the immune cells with the tumor's specific genetic sequence, training the patient's body to attack their own unique type of cancer.
"It means you're able to think about personalizing cancer treatments down to specific subgroups of patients," says Mulqueen. "For example, eTheRNA are developing a renal cell carcinoma treatment which will be targeted at around 20% of these patients, who have specific tumor types. We're hoping to take that to human trials next year, but the challenge is trying to identify the right patients for the treatment at an early stage."
Repairing Damaged mRNA
While hopes are high that mRNA could usher in new cancer treatments and make CRISPR more accessible, a growing number of companies are also exploring an alternative to gene editing, known as RNA editing.
In genetic disorders, the mRNA in certain cells is impaired due to a rogue gene defect, and so the body ceases to produce a particular vital protein. Instead of permanently deleting the problem gene with CRISPR, the idea behind RNA editing is to inject small pieces of synthetic mRNA to repair the existing mRNA. Scientists think this approach will allow normal protein production to resume.
Over the past few years, this approach has gathered momentum, as some researchers have recognized that it holds certain key advantages over CRISPR. Companies from Belgium to Japan are now looking at RNA editing to treat all kinds of disorders, from Huntingdon's disease, to amyotrophic lateral sclerosis, or ALS, and certain types of cancer.
"With RNA editing, you don't need to make any changes to the DNA," explains Daniel de Boer, CEO of Dutch biotech ProQR, which is looking to treat rare genetic disorders that cause blindness. "Changes to the DNA are permanent, so if something goes wrong, that may not be desirable. With RNA editing, it's a temporary change, so we dose patients with our drugs once or twice a year."
Last month, ProQR reported a landmark case study, in which a patient with a rare form of blindness called Leber congenital amaurosis, which affects the retina at the back of the eye, recovered vision after three months of treatment.
"We have seen that this RNA therapy restores vision in people that were completely blind for a year or so," says de Boer. "They were able to see again, to read again. We think there are a large number of other genetic diseases we could go after with this technology. There are thousands of different mutations that can lead to blindness, and we think this technology can target approximately 25% of them."
Ultimately, there's likely to be a role for both RNA editing and CRISPR, depending on the disease. "I think CRISPR is ideally suited for illnesses where you would like to permanently correct a genetic defect," says Joshua Rosenthal of the Marine Biology Laboratory in Chicago. "Whereas RNA editing could be used to treat things like pain, where you might want to reset a neural circuit temporarily over a shorter period of time."
Much of this research has been accelerated by the COVID-19 pandemic, which has played a major role in bringing mRNA to the forefront of people's minds as a therapeutic.
"The pandemic has really shown that not only are mRNA approaches viable, they could in certain circumstances be vastly superior to more traditional technologies," says Mulqueen. "In the future, I would not be surprised if many of the top pharma products are mRNA derived."
"Making Sense of Science" is a monthly podcast that features interviews with leading medical and scientific experts about the latest developments and the big ethical and societal questions they raise. This episode is hosted by science and biotech journalist Emily Mullin, summer editor of the award-winning science outlet Leaps.org.