Welcome to Science of the Scare! Every month I will dissect a Big Science Question from a horror movie and talk through it in (mostly) easy-to-digest terms.
Science and horror have a wild, entangled history and have left us with loads of questions to ponder. Deep, important questions like: just how many ways could we have a zombie pandemic? Is genetic engineering always a slippery slope to monstrosity? This month’s Big Science Question:
Can stem cells grant you immortality?
Justin Benson and Aaron Moorhead’s Spring (2014), dubbed a “romantic body horror” film, follows Evan (Lou Taylor Pucci), a disenchanted twenty-something who takes himself on a trip to Italy after his mother’s death. There he meets Louise (Nadia Hilker) a beautiful and enigmatic Italian woman and he is instantly smitten beyond reason. But Louise has a secret (because of course she does): she is a 2,000-year old mutant. Every 20 years, she intentionally gets pregnant and incorporates the embryonic stem cells from her pregnancy into her transformation into a new human form, making her effectively immortal. Whenever her 20th spring in a given form approaches, her body is prone to eldritch transformations. She controls this symptom as much as she can with stem cell injections that she produces in a lab where she works as a genetics student.
The fact that Louise‘s research is based in Italy is relevant. When she is explaining her research to Evan she tells him that small towns in Italy are useful for genetics studies because there is little genetic variation in the small populations. What she doesn’t say is that some of these small communities, places like Sardinia, Italy, are known for special genetic trends. Sardinians, in particular, is known for its unusually concentrated number of super-centenarians, AKA people who make it past their 110th Birthday. Is it possible that Louise‘s multimillennial lifespan is a further genetic twist of Sardinian longevity?
Louise makes it clear that living forever is super important to her, and her strategy isn’t unreasonable. The key to living forever is having a body that’s up to the task. Your body’s cells are only built to last for so long. A cell’s usefulness is dictated by its ability to divide and replicate the DNA contained without introducing errors or mutation. Normally, when an aging cell detects that it has reached its limit of healthy divisions, it will become senescent and stop dividing. A cell might also enter a stage of programmed cell death known as apoptosis. Basically, the cell will sacrifice itself for the common good of your organs and surrounding newer, healthier cells will pick up its slack (this is also a way of maintaining the appropriate number of cells in a tissue, with new cells replacing old). The tissue deterioration that we see as we age is pretty much thanks to cell senescence and apoptosis.
This is where stem cells come in to fight it. You’ve probably heard of stem cells before: they’re a type of cell that is undifferentiated, which is to say that it’s a raw cell that hasn’t yet learned to become a heart cell or a lung cell or a toenail cell. There are different types of stem cells, but in general, they prove useful for therapies because we can guide these undifferentiated cells into become specialized healthy heart cells or lung cells or toenail cells and have them replace or repair damaged or diseased tissue. The cells that Louise is using in her lab to produce her stem cell injections are adult stem cells, often harvested from bone marrow. Adult stem cells are more limited in their regenerative ability. There are also only so many stem cells in each injection, which is why Louise has to treat her condition regularly to control her morphing.
“Getting pregnant is useful for Louise because early embryos are basically just balls of pluripotent stem cells that can give rise to any sort of cell in the human body.”
Compared to adult stem cells, embryonic stem cells have a lot more regenerative potential. Getting pregnant is useful for Louise because early embryos are basically just balls of pluripotent stem cells that can give rise to any sort of cell in the human body. Somehow, Louise‘s bizarre biology lets her therapeutically absorb the embryonic stems cells from her pregnancy to reset her own cells.
One thing that’s interesting is that adult stem cells can be reprogrammed to become Induced Pluripotent Stem Cells (iPSCs), which means that they are stem cells harvested from adults, but they behave more like embryonic stem cells. Recently, there has been a good amount of research going into using iPSCs to turn the clock back on premature aging. Other research has looked specifically at finding ways to reset senescent cells in mice with progeria, a medical condition that causes premature aging. By introducing reprogramming factors — usually expressed in embryonic stem cells — into senescent cells, the senescent cells can be reset and start behaving like brand spanking new cells. This also means that some of the visible deterioration that comes with aging can be reversed. This can be done in human cells, too, and it’s my best comparison to what’s naturally going on inside Louise‘s body when be absorbs her pregnancies. The only major difference is that, when Louise‘s body resets, she incorporates genetic information from the embryo and takes on genetic traits donated to her by her sex partner.
“Recently, there has been a good amount of research going into using [stem cells] to turn the clock back on premature aging.”
The biggest caveat to Louise‘s mutation is that increased levels of oxytocin in her blood will prevent her transformation and set her on a mortal path. People love to call oxytocin the “love hormone” because it has been associated with social bonding, orgasm, and romantic attachment, but it also has a ton of other functions, mostly tied to pregnancy, childbirth, and milk letdown for breast-feeding. Louise has tried to be a lone wolf for so long because a spike in the amount of oxytocin floating around in her bloodstream will change how her body responds to its pregnancy, seeing it through instead of cannibalizing the embryo to add a couple more decades to her lifespan.
Props go to Evan for being clearly very smitten with his mutant girlfriend because, despite witnessing her in all of her goopy and gory eldritch glory, he sticks by her in hope that she’ll love him back enough to sacrifice her immortality with a rush of oxytocin.