SCOOP: Largest Cryobank in the U.S. to Offer Ancestry Testing
Sharon Kochlany and Vanessa Colimorio's four-year-old twin girls had a classic school assignment recently: make a family tree. They drew themselves and their one-year-old brother branching off from their moms, with aunts, uncles, and grandparents forking off to the sides.
The recently-gained sovereignty of queer families stands to be lost if a consumer DNA test brings a stranger's identity out of the woodwork.
What you don't see in the invisible space between Kochlany and Colimorio, however, is the sperm donor they used to conceive all three children.
To look at a family tree like this is to see in its purest form that kinship can supersede biology—the boundaries of where this family starts and stops are clear to everyone in it, in spite of a third party's genetic involvement. This kind of self-definition has always been synonymous with LGBTQ families, especially those that rely on donor gametes (sperm or eggs) to exist.
But the world around them has changed quite suddenly: The recent consumer DNA testing boom has made it more complicated than ever for families built through reproductive technology—openly, not secretively—to maintain the strong sense of autonomy and privacy that can be crucial for their emotional security. Prospective parents and cryobanks are now mulling how best to bring a new generation of donor-conceived people into this world in a way that leaves open the choice to know more about their ancestry without obliterating an equally important choice: the right not to know about biological relatives.
For queer parents who have long fought for social acceptance, having a biological relationship to their children has been revolutionary, and using an unknown donor as a means to this end especially so. Getting help from a friend often comes with the expectation that the friend will also have social involvement in the family, which some people are comfortable with, but being able to access sperm from an unknown donor—which queer parents have only been able to openly do since the early 1980s—grants them the reproductive autonomy to create families seemingly on their own. That recently-gained sovereignty stands to be lost if a consumer DNA test brings a stranger's identity out of the woodwork.
At the same time, it's natural for donor-conceived people to want to know more about where they come from ethnically, even if they don't want to know the identity of their donor. As a donor-conceived person myself, I know my donor's self-reported ethnicity, but have often wondered how accurate it is.
Opening the Pandora's box of a consumer DNA test as a way to find out has always felt profoundly unappealing to me, however. Many people have accidentally learned they're donor-conceived by unwittingly using these tools, but I already know that about myself going in, and subsequently know I'll be connected to a large web of people whose existence I'm not interested in learning about. In addition to possibly identifying my anonymous donor, his family could also show up, along with any donor-siblings—other people with whom I share a donor. My single lesbian mom is enough for me, and the trade off to learn more about my ethnic ancestry has never seemed worth it.
In 1992, when I was born, no one was planning for how consumer DNA tests might upend or illuminate one's sense of self. But the donor community has always had to stay nimble with balancing privacy concerns and psychological well-being, so it should come as no surprise that figuring out how to do so in 2020 includes finding a way to offer ancestry insight while circumventing consumer DNA tests.
A New Paradigm
This is the rationale behind unprecedented industry news that LeapsMag can exclusively break: Within the next few weeks, California Cryobank, the largest cryobank in the country, will begin offering genetically-verified ancestry information on the free public part of every donor's anonymous profile in its database, something no other cryobanks yet offer (an exact launch date was not available at the time of publication). Currently, California Cryobank's donor profiles include a short self-reported list that might merely say, "Ancestry: German, Lebanese, Scottish."
The new information will be a report in pie chart form that details exactly what percentages of a donor's DNA come from up to 26 ethnicities—it's analogous to, but on a smaller scale than, the format offered by consumer DNA testing companies, and uses the same base technology that looks for single nucleotide polymorphisms in DNA that are associated with specific ethnicities. But crucially, because the donor takes the DNA test through California Cryobank, not a consumer-facing service, the information is not connected in a network to anyone else's DNA test. It's also taken before any offspring exist so there's no chance of revealing a donor-conceived person's identity this way.
Later, when a donor-conceived person is born, grows up, and wants information about their ethnicity from the donor side, all they need is their donor's anonymous ID number to look it up. The donor-conceived person never takes a genetic test, and therefore also can't accidentally find donor siblings this way. People who want to be connected to donor siblings can use a sibling registry where other people who want to be found share donor ID numbers and look for matches (this is something that's been available for decades, and remains so).
"With genetic testing, you have no control over who reaches out to you, and at what point in your life."
California Cryobank will require all new donors to consent to this extra level of genetic testing, setting a new standard for what information prospective parents and donor-conceived people can expect to have. In the immediate, this information will be most useful for prospective parents looking for donors with specific backgrounds, possibly ones similar to their own.
It's a solution that was actually hiding in plain sight. Two years ago, California Cryobank's partner Sema4, the company handling the genetic carrier testing that's used to screen for heritable diseases, started analyzing ethnic data in its samples. That extra information was being collected because it can help calculate a more accurate assessment of genetic risks that run in certain populations—like Ashkenazi Jews and Tay Sachs disease—than relying on oral family histories. Shortly after a plan to start collecting these extra data, Jamie Shamonki, chief medical officer of California Cryobank, realized the companies would be sitting on a goldmine for a different reason.
"I didn't want to use one of these genetic testing companies like Ancestry to accomplish this," says Shamonki. "The whole thing we're trying to accomplish is also privacy."
Consumer-facing DNA testing companies are not HIPAA compliant (whereas Sema4, which isn't direct-to-consumer, is HIPAA compliant), which means there are no legal privacy protections covering people who add their DNA to these databases. Although some companies, like 23andMe, allow users to opt-out of being connected with genetic relatives, the language can be confusing to navigate, requires a high level of knowledge and self-advocacy on the user's part, and, as an opt-out system, is not set up to protect the user from unwanted information by default; many unwittingly walk right into such information as a result.
Additionally, because consumer-facing DNA testing companies operate outside the legal purview that applies to other health care entities, like hospitals, even a person who does opt-out of being linked to genetic relatives is not protected in perpetuity from being re-identified in the future by a change in company policy. The safest option for people with privacy concerns is to stay out of these databases altogether.
For California Cryobank, the new information about donor heritage won't retroactively be added to older profiles in the system, so donor-conceived people who already exist won't benefit from the ancestry tool, but it'll be the new standard going forward. The company has about 500 available donors right now, many of which have been in their registry for a while; about 100 of those donors, all new, will have this ancestry data on their profiles.
Shamonki says it has taken about two years to get to the point of publicly including ancestry information on a donor's profile because it takes about nine months of medical and psychological screening for a donor to go from walking through the door to being added to their registry. The company wanted to wait to launch until it could offer this information for a significant number of donors. As more new donors come online under the new protocol, the number with ancestry information on their profiles will go up.
For Parents: An Unexpected Complication
While this change will no doubt be welcome progress for LGBTQ families contemplating parenthood, it'll never be possible to put this entire new order back in the box. What are such families who already have donor-conceived children losing in today's world of widespread consumer genetic testing?
Kochlany and Colimorio's twins aren't themselves much older than the moment at-home DNA testing really started to take off. They were born in 2015, and two years later the industry saw its most significant spike. By now, more than 26 million people's DNA is in databases like 23andMe and Ancestry; as a result, it's estimated that within a year, 90 percent of Americans of European descent will be identifiable through these consumer databases, by way of genetic third cousins, even if they didn't want to be found and never took the test themselves. This was the principle behind solving the Golden State Killer cold case.
The waning of privacy through consumer DNA testing fundamentally clashes with the priorities of the cyrobank industry, which has long sought to protect the privacy of donor-conceived people, even as open identification became standard. Since the 1980s, donors have been able to allow their identity to be released to any offspring who is at least 18 and wants the information. Lesbian moms pushed for this option early on so their children—who would obviously know they couldn't possibly be the biological product of both parents—would never feel cut off from the chance to know more about themselves. But importantly, the openness is not a two-way street: the donors can't ever ask for the identities of their offspring. It's the latter that consumer DNA testing really puts at stake.
"23andMe basically created the possibility that there will be donors who will have contact with their donor-conceived children, and that's not something that I think the donor community is comfortable with," says I. Glenn Cohen, director of Harvard Law School's Center for Health Law Policy, Biotechnology & Bioethics. "That's about the donor's autonomy, not the rearing parents' autonomy, or the donor-conceived child's autonomy."
Kochlany and Colimorio have an open identification donor and fully support their children reaching out to California Cryobank to get more information about him if they want to when they're 18, but having a singular name revealed isn't the same thing as having contact, nor is it the same thing as revealing a web of dozens of extended genetic relations. Their concern now is that if their kids participate in genetic testing, a stranger—someone they're careful to refer to as only "the donor" and never "dad"—will reach out to the children to begin some kind of relationship. They know other people who are contemplating giving their children DNA tests, and feel staunchly that it wouldn't be right for their family.
"With genetic testing, you have no control over who reaches out to you, and at what point in your life," Kochlany says. "[People] reaching out and trying to say, 'Hey I know who your dad is' throws a curveball. It's like, 'Wait, I never thought I had a dad.' It might put insecurities in their minds."
"We want them to have the opportunity to choose whether or not they want to reach out," Colimorio adds.
Kochlany says that when their twins are old enough to start asking questions, she and Colimorio plan to frame it like this: "The donor was kind of like a technology that helped us make you a person, and make sure that you exist," she says, role playing a conversation with their kids. "But it's not necessarily that you're looking to this person [for] support or love, or because you're missing a piece."
It's a line in the sand that's present even for couples still far off from conceiving. When Mallory Schwartz, a film and TV producer in Los Angeles, and Lauren Pietra, a marriage and family therapy associate (and Shamonki's step-daughter), talk about getting married someday, it's a package deal with talking about how they'll approach having kids. They feel there are too many variables and choices to make around family planning as a same-sex couple these days to not have those conversations simultaneously. Consumer DNA databases are already on their minds.
"It frustrates me that the DNA databases are just totally unregulated," says Schwartz. "I hope they are by the time we do this. I think everyone deserves a right to privacy when making your family [using a sperm donor]."
"I wouldn't want to create a world where people who are donor-conceived feel like they can't participate in this technology because they're trying to shut out [other] information."
On the prospect of having a donor relation pop up non-consensually for a future child, Pietra says, "I don't like it. It would be really disappointing if the child didn't want [contact], and unfortunately they're on the receiving end."
You can see how important preserving the right to keep this door closed is when you look at what's going on at The Sperm Bank of California. This pioneering cryobank was the first in the world to openly serve LGBTQ people and single women, and also the first to offer the open identification option when it opened in 1982, but not as many people are asking for their donor's identity as expected.
"We're finding a third of young people are coming forward for their donor's identity," says Alice Ruby, executive director. "We thought it would be a higher number." Viewed the other way, two-thirds of the donor-conceived people who could ethically get their donor's identity through The Sperm Bank of California are not asking the cryobank for it.
Ruby says that part of what historically made an open identification program appealing, rather than invasive or nerve-wracking, is how rigidly it's always been formatted around mutual consent, and protects against surprises for all parties. Those [donor-conceived people] who wanted more information were never barred from it, while those who wanted to remain in the dark could. No one group's wish eclipsed the other's. The potential breakdown of a system built around consent, expectations, and respect for privacy is why unregulated consumer DNA testing is most concerning to her as a path for connecting with genetic relatives.
For the last few decades in cryobanks around the world, the largest cohort of people seeking out donor sperm has been lesbian couples, followed by single women. For infertile heterosexual couples, the smallest client demographic, Ruby says donor sperm offers a solution to a medical problem, but in contrast, it historically "provided the ability for [lesbian] couples and single moms to have some reproductive autonomy." Yes, it was still a solution to a biological problem, but it was also a solution to a social one.
The Sperm Bank of California updated its registration forms to include language urging parents, donor-conceived people, and donors not to use consumer DNA tests, and to go through the cryobank if they, understandably, want to learn more about who they're connected to. But truthfully, there's not much else cryobanks can do to protect clients on any side of the donor transaction from surprise contact right now—especially not from relatives of the donor who may not even know someone in their family has donated sperm.
A Tricky Position
Personally, I've known I was donor-conceived from day one. It has never been a source of confusion, angst, or curiosity, and in fact has never loomed particularly large for me in any way. I see it merely as a type of reproductive technology—on par with in vitro fertilization—that enabled me to exist, and, now that I do exist, is irrelevant. Being confronted with my donor's identity or any donor siblings would make this fact of my conception bigger than I need it to be, as an adult with a full-blown identity derived from all of my other life experiences. But I still wonder about the minutiae of my ethnicity in much the same way as anyone else who wonders, and feel there's no safe way for me to find out without relinquishing some of my existential independence.
The author and her mom in spring of 1998.
"People obviously want to participate in 23andMe and Ancestry because they're interested in knowing more about themselves," says Shamonki. "I wouldn't want to create a world where people who are donor-conceived feel like they can't participate in this technology because they're trying to shut out [other] information."
After all, it was the allure of that exact conceit—knowing more about oneself—that seemed to magnetically draw in millions of people to these tools in the first place. It's an experience that clearly taps into a population-wide psychic need, even—perhaps especially—if one's origins are a mystery.
Air pollution can lead to lung cancer. The connection suggests new ways to stop cancer in its tracks.
Forget taking a deep breath. Around the world, 99 percent of people breathe air polluted to unsafe levels, according to data from the World Health Organization. Activities such as burning fossil fuels release greenhouse gases that contribute to air pollution, which could lead to heart disease, stroke, asthma, emphysema, and some types of cancer.
“The burden of disease attributable to air pollution is now estimated to be on a par with other major global health risks such as unhealthy diet and tobacco smoking, and air pollution is now recognized as the single biggest environmental threat to human health,” wrote the authors of a 2021 WHO report.
The majority of lung cancer is attributed to smoking. But as pollution levels have increased, and anti-smoking campaigns have discouraged smoking, the proportion of lung cancers diagnosed in non-smokers has grown. The CDC estimates that 10 to 20 percent of lung cancers in the U.S. currently occur in non-smokers.
The mechanism between air pollution and the development of lung cancer has been unclear, but researchers at London’s Francis Crick Institute recently made an important breakthrough in understanding the connection. Lead investigator Charles Swanton presented this research last month at a conference in Paris.
Pollution awakens mutations
The Crick Institute scientists were able to identify a new link between common air pollutants and non-small cell lung cancer (NSCLC). They focused on pollutants called particulate matter, or PM, that are 2.5 microns wide, narrower than human cells.
Most cancer diagnosed in non-smoking people is NSCLC, but this type of cancer hasn’t received the same research attention as more common lung cancers found in smokers, according to Clare Weeden, a cancer researcher at the Crick Institute and a co-author of the study.
“This is a really underserved and under-researched population that we really need to tackle, as well as lung cancers that occur in smokers,” she says. “Lung cancer is the number one cancer killer worldwide.”
In the past, some researchers believed air pollution caused mutations that led to cancer. Others believed these mutations could remain dormant without any detriment to health until pollutants or other stressors triggered them to become cancerous. Reviving the latter hypothesis that carcinogens may activate pre-existing mutations, instead of directly causing them, the Crick researchers analyzed samples from 463,679 people in the UK and parts of Asia, noting mutations and comparing changes in gene expression in mice and human cells.
“The mutation can exist in a nascent clone without causing cancer,” says Emilia Lim, a bioinformatics expert and a co-first author of the Crick study. “It is the carcinogen that promotes a conducive environment for this one little clone to grow and expand into cancer. Through our work, we were able to revive excitement for this hypothesis and bring it to light.”
The study explains a confusing pattern of lung cancer developing, particularly in women, despite a lack of environmental risk factors like smoking, secondhand smoke, or radon exposure. The culprit in these cases may have been too much PM 2.5 exposure.
Other researchers had previously identified a link between mutations in certain genes that control epidermal growth factor receptors, or EGFR mutations, and the development of NSCLC. In a 2019 study of 250 people with this type of cancer, about 32 percent had the mutation. Women are more likely to have EGFR mutations than men.
Not everyone who has the EGFR mutation will develop lung cancer. Respirologist Stephen Lam studies lung cancer at the BC Cancer Research Centre in Vancouver, Canada, but was not involved in the Crick Institute research. He says the study explains a confusing pattern of lung cancer developing, particularly in women, despite a lack of environmental risk factors like smoking, secondhand smoke, or radon exposure. The culprit in these cases may have been too much PM 2.5 exposure.
More exposure leads to inflammation and lesions
The Crick researchers found that an excess of PM 2.5 in the air sparked an inflammatory process in cells within the lung. This inflammation set the stage for NSCLC to develop in people and mice with existing EGFR mutations.
The researchers also exposed mice without EGFR mutations to PM 2.5 pollution—an experiment that couldn’t be ethically conducted in humans—to link pollution exposure to NSCLC. The mice experiments also showed that NSCLC is dose-dependent; higher levels of exposure were associated with higher number of cancerous lesions forming.
Ultimately, the study “fundamentally changed how we view lung cancer in people who have never smoked,” said Swanton in a Crick Institute press release. “Cells with cancer-causing mutations accumulate naturally as we age, but they are normally inactive. We’ve demonstrated that air pollution wakes these cells up in the lungs, encouraging them to grow and potentially form tumors.”
Preventing cancer before it begins
Targeted therapies already exist for people with EGFR mutations who’ve developed NSCLC, but they have many side effects, according to Weeden. Researchers hope that making more definitive links between pollutants and cancer could help prevent people with EGFR or other mutations from developing lung cancer in the first place.
Along those lines, as an additional component of their study presented last month, the Crick researchers were able to prevent cancer in mice that had the EGFR mutations by blocking inflammation. They used an antibody to inhibit a protein called interleukin 1 beta, which plays a key role in inflammation. Scientists could eventually use such antibodies or other therapies to make a drug treatment that people can take to stop cancer in its tracks, even if they live in highly polluted areas.
Such potential could reach beyond lung cancer; in the past, Crick and other researchers have also found associations between exposure to air pollution and mesothelioma, as well as cancers of the small intestine, lip, mouth, and throat. These links could be meaningful to a growing number of people as climate change intensifies, and with increases in air pollution from fossil fuel combustion and natural disasters like forest fires.
Plus, air pollution is just one external condition that can flip the switch of these inflammatory pathways. Identifying a link between pollution and cancer “has wide ramifications for many other environmental factors that may [play] similar roles,” Weedon says. She hopes that the Crick study and future research in this area will offer some hope for non-smokers frustrated by cancer diagnoses.
Naked Mole Rats Defy Aging. One Scientist Has Dedicated Her Career to Finding Out How.
Rochelle "Shelley" Buffenstein has one of the world's largest, if not the largest, lab-dwelling colonies of the naked mole rat. (No one has done a worldwide tabulation, but she has 4,500 of them.) Buffenstein has spent decades studying the little subterranean-dwelling rodents. Over the years, she and her colleagues have uncovered one surprising discovery after another, which has led them to re-orient the whole field of anti-aging research.
Naked mole rats defy everything we thought we knew about aging. These strange little rodents from arid regions of Africa, such as Kenya, Ethiopia and Somalia, live up to ten times longer than their size would suggest. And unlike virtually every other animal, they don't lose physical or cognitive abilities with age, and even retain their fertility up until the end of life. They appear to have active defenses against the ravages of time, suggesting that aging may not be inevitable. Could these unusual creatures teach humans how to extend life and ameliorate aging?
Buffenstein, who is senior principle investigator at Calico Life Sciences, has dedicated her life to finding out. Her early interest in the animals of what is now Zimbabwe led to her current position as a cutting-edge anti-aging researcher at Calico, the Google-funded health venture launched in 2013. The notoriously secretive company is focused on untangling the mysteries of why animals and people age, and whether there are ways to slow or temporarily arrest the process.
The small, wrinkly animal, which lives in underground burrows in the hot, arid regions of Africa, is hardly the beauty queen of the mammalian kingdom. Furless, buck-toothed and tiny-eyed, the creatures look like they could use a good orthodontist, a protective suit of clothes and possibly, some spectacles to enhance their eyesight. But these rats more than make up for their unimpressive looks with their superlative ability to adapt to some of the most inhospitable conditions on earth.
Based on the usual rule that body size predicts lifespan, naked mole rats shouldn't live that long. After all, similarly-sized rodents like mice have a life expectancy of two years or less. But Buffenstein was one of the first scientists to recognize that naked mole rats live an extraordinarily long time, with her oldest animal approaching 39 years of age. In addition, they never become geriatric in the human sense, defying the common signs of aging — age-related diseases, cognitive decline and even menopause. In fact, the queens, or females that do all the breeding in a bee-like underground colony, remain fertile and give birth to healthy pups up until what would be considered very old age in humans. And the naked mole rat has other curious abilities, such as the ability to endure extreme low-oxygen, or hypoxic, conditions like those they encounter in their underground nests.
"One thing we've learned from these animals is that they stay healthy until the very end."
It's not that the naked mole rat isn't subject to the vicissitudes of life, or the normal wear and tear of biological processes. Over the years, Buffenstein and her colleagues have discovered that, while the process of oxidative stress — thought for 50 years to be the main cause of aging — occurs in the naked mole rat just as in any other animal, its damage does not accumulate with age. Oxidative stress occurs during normal cell metabolism when oxygen "free radicals" with one or more unpaired electrons wreak havoc on large cellular molecules, leaving microscopic debris in their wake that clogs up the gears of healthy cell function. Somehow, naked mole rats have an enhanced ability to clear out the damaged cells and molecules before they can set off the usual chain reaction of cell dysfunction and death, according to a 2013 paper in which Buffenstein is the lead author.
Oxidative stress is not the only factor known to be problematic in aging. Slowly accumulating damage to DNA typically leads to protein malfunction and improper folding. In humans and most other animals, these protein fragments can accumulate in cells and gum up the works. Only not so much in naked mole rats, which are able to maintain normal protein folding throughout their long life. After years of discoveries like these, Buffenstein has gradually reframed her focus from "what goes wrong to produce aging?" to "what goes right in the naked mole rat to help it defy the normal wear and tear of life?" Buffenstein's research suggests that the tiny mammals have a unique ability to somehow clear out damaged protein fragments and other toxic debris before they can cause disease and aging.
How She Got Here
Buffenstein ascribes her initial acquaintance with the naked mole rat to serendipity. Back in 1979, her postgraduate mentor Jenny Jarvis at the University of Cape Town in South Africa kept a small colony of rats in her office while studying the mechanisms that lead to the animals' unusual adaptive capabilities. It was Buffenstein's job to take care of them. Working with Jarvis, Buffenstein focused on understanding their unique adaptations to the extreme conditions of their natural habitat.
They studied the unusual behaviors regulating the rat colonies. For instance, they observed that designated "workers" dig the entire colony's underground tunnels and a single reproducing female breeds with only a small number of males. Buffenstein also examined how these animals are able to survive without the "sunshine hormone" — vitamin D — and their unusual modes of regulating their internal temperatures and converting food into energy. Though classified as mammals, the rodents simply don't conform to the mammalian handbook, having found ingenuous ways to alter their bodies and behavior that is fine-tuned to the scorching heat and aridity of their environment.
To escape the heat, they simply burrow underground and live in elaborate tunnels. To cope with the low-oxygen conditions underground, they slowed their metabolism and learned to live for extended periods of time in such hypoxic conditions that an ordinary animal would quickly suffocate. But it was slowly dawning on Buffenstein that the small creatures were exceptional in additional ways.
When Buffenstein got her first academic position at the University of Witwatersrand in Johannesburg, Jarvis said she could take some of the naked mole rats with her. When she did, Buffenstein noticed that the animals were living far longer than similarly sized rodents. "At that stage, they were about ten years old. Little did I know how long they would eventually show us they could live," she says.
In 1997, after accepting a position at the City College of New York, Buffenstein moved to the U.S. and took her rat colony with her. There she was able to pursue an evolving narrative about the humble naked mole rat that continued to defy expectations. As the years passed, it was becoming more and more evident that her observations could have major implications for aging research. Eventually, she took a position at the Barshop Institute for Aging and Longevity Studies in San Antonio, Texas.
One early observation of Buffenstein's suggested that the species most often used in aging research—mice, roundworms, fruit flies and yeast—have short lifespans and poor defenses against aging. These animals provide important insights into how aging works, and have revealed possible targets for intervention. But they don't show what goes right in apparently non-aging animals like the naked mole rat.
Buffenstein's years of studying the rats has laid the foundation for a whole new perspective in aging research.
"My hypothesis," she says, "is that naked mole rats are very good at removing damaged macromolecules and cells, thereby maintaining homeostasis and cell and tissue function. All the repair pathways examined by us and others in the field point to more efficient repair and more rapid responses to damaging agents." These include things like free radicals and radiation.
Buffenstein’s Legacy
Some researchers today are building on Buffenstein's foundational discoveries to home in on possible anti-aging mechanisms that lead to the extraordinary resilience of naked mole rats. University of Cambridge researcher and co-founder of the institution's Naked Mole-Rat Initiative, Ewan St. John Smith, is studying the animal's resistance to cancer.
In a 2020 paper published in Nature, Smith and his colleagues established that naked mole rats harbor cancer-causing genes, and these genes occasionally create cancer cells. But something in the rats shuts the multiplication process down before the cells can grow out of control and form tumors. Now, scientists want to know what mechanisms, exactly, are at play in preventing the cells from invading healthy tissues. Smith has hypothesized that the answer is somehow embedded in interactions in the cells' microenvironment.
He also thinks the animal's immune system could just be very effective at seeking out and destroying cancer cells. Several current cancer therapies work by boosting the body's immune system so it can attack and eliminate the toxic cells. It's possible that the naked mole rat's immune system naturally goes into hyper-drive when cancer cells appear, enabling it to nip the disease in the bud before tumors can form. A pharmacologist by training, Smith thinks that if there is some chemical mediator in the naked mole rat that supercharges its immune cells, perhaps that mediator can be synthesized in a drug to treat humans for cancer.
The naked mole rat's extreme tolerance to hypoxia could also play a role. "Interestingly," he says, "when cells become cancerous, they also become hypoxic, and naked mole rats are known to be very resistant to hypoxia.
He notes that a form of low-level hypoxia is also present in the bodies and brains of both aged mice and older humans. It's commonly seen in the brains of humans with Alzheimer's disease and other forms of age-related dementia. This suggests that hypoxia in humans — and in other mammals — may have a role to play in Alzheimer's and the aging process itself. Resistance to hypoxia could be why the naked mole rat, in Smith's words, "chugs along quite happily" in conditions that in humans are associated with disease and decline.
Smith cheerfully acknowledges his debt to Buffenstein for laying so much of the groundwork in a field rife with possible implications for anti-aging. "Shelley is amazing," he says. "Naked mole rats have a queen and I always refer to her as the queen of the naked mole rat world." In fact, Buffenstein gave Smith his first colony of rats, which he's since grown to about 150. "Some of them will still be around when I retire," he jokes.
Vera Gorbunova, a professor of biology and oncology at the University of Rochester who studies both longevity and cancer in naked mole rats, credits Buffenstein with getting others to study the animals for anti-aging purposes. Gorbunova believes that "cancer and aging go hand-in-hand" and that longer-lived animals have better, more accurate DNA repair.
Gorbunova is especially interested in the naked mole rat's ability to secrete a superabundance of a "super-sugar" molecule called hyaluronan, a ubiquitous additive to skin creams for its moisturizing effect. Gorbunova and others have observed that the presence of high concentrations of hyaluronan in the naked mole rat's extracellular matrix — the chemical-rich solution between cells — prevents the overcrowding of cells. This, perhaps, could be the key to the animal's ability to stop tumors from forming.
Hyaluronan is also present in the extracellular matrix of humans, but the naked mole rat molecule is more than five times larger than the versions found in humans or mice, and is thought to play a significant part in the animal's DNA repair. But just rubbing a cream containing hyaluronan over your skin won't stop cancer or aging. High concentrations of the substance in the extracellular matrix throughout your body would likely be needed.
Gorbunova notes that the naked mole rat offers a multitude of possibilities that could eventually lead to drugs to slow human aging. "I'm optimistic that there are many different strategies, because the naked mole rat likely has many processes going on that fight aging," she says. "I think that in a relatively short time, there will be bonafide treatments to test in animals. One thing we've learned from these animals is that they stay healthy until the very end."
So if naked mole rats don't become frail with age or develop age-related diseases, what does kill them? The answer, unfortunately, is usually other naked mole rats. Buffenstein has long noted that even though they live in highly cooperative colonies, they can be quite cantankerous when there's a disruption in the hierarchy, a sentiment echoed by Gorbunova. "Sometimes there are periods of peace and quiet, but if something happens to the queen, all hell breaks loose," she says. "If the queen is strong, everybody knows their place," but if the queen dies, the new queen is inevitably decided by violent competition.
To the casual observer, a strange, wrinkly rodent like the naked mole rat might seem to have little to teach us about ourselves, but Buffenstein is confident that her discoveries could have major implications for human longevity research. Today, at Calico's labs in San Francisco, she's focused entirely on the determining how anti-aging defense mechanisms in the rats could lead to similar defenses being stimulated or introduced in humans.
"The million-dollar question is, what are the mechanisms protecting against aging, and can these be translated into therapies to delay or abrogate human aging, too?"
Buffenstein fired up a new generation of scientists with multiple discoveries, especially the fundamental one that naked mole rats are subject to the same wear and tear over time as the rest of us, but somehow manage to reverse it. These days, the trailblazer is at work on untangling the molecular mechanisms involved in the animal's resistance to cardiac aging. On top of everything else, the small creature has a unique ability to fight off the scourge of heart disease, which is the leading cause of death in the industrialized world.
After all, the point is not to extend old age, but to slow down aging itself so that frailty and disability are compressed into a brief period after a long-extended period of vitality. By switching the focus from what goes wrong to mechanisms that defend against aging in the first place, the discoveries of Buffenstein and a new generation of researchers who are building on her groundbreaking research promise to be a driving force in the quest to extend not only life, but healthy, vigorous life in humans.
This article was first published by Leaps.org on June 23, 2021.