imagine something small enough to floaton a particle of dust that holds the keys to understandingcancer, virology, and genetics. luckily for us, such a thing exists in the form of trillions upon trillions of human lab-grown cellscalled hela. let's take a step back for a second. scientists grow human cells in the labto study how they function, understand how diseases develop, and test new treatments withoutendangering patients.
to make sure that they can repeatthese experiments over and over, and compare the results with other scientists, they need huge populations of identical cells that can duplicate themselves faithfully for years, but until 1951, all human cell linesthat researchers tried to grow had died after a few days. then a john hopkins scientistnamed george gey received a sample of a strange looking tumor: dark purple, shiny, jelly-like.
this sample was special. some of its cells just kept dividing, and dividing, and dividing. when individual cells died, generations of copies took their placeand thrived. the result was an endless source ofidentical cells that's still around today. the very first immortal human cell line. gey labeled it "hela" after the patientwith the unusual tumor, henrietta lacks.
born on a tobacco farm in virginia, she lived in baltimore with her husbandand five children. she died of aggressive cervical cancer a few months after her tumorous cellswere harvested, and she never knew about them. so what's so special about the cellsfrom henrietta lacks that lets them survivewhen other cell lines die? the short answer iswe don't entirely know. normal human cells have built-incontrol mechanisms.
they can divide about 50 timesbefore they self destruct in a process called apoptosis. this prevents the propagationof genetic errors that creep in after repeated rounds of division. but cancer cells ignore these signals,dividing indefinitely and crowding out normal cells. still, most cell lines eventually die off,especially outside the human body. not hela, though, and that's the partwe can't yet explain. regardless, when dr. gey realized he hadthe first immortal line of human cells,
he sent samples to labs all over the world. soon the world's first cell production facility was churning out 6 trillion hela cells a week, and scientists put them to workin an ethically problematic way, building careers and fortunesoff of henrietta's cells without her or her family's consent,or even knowledge until decades later. the polio epidemic was at its peakin the early 50s. hela cells, which easily took upand replicated the virus, allowed jonas salk to test his vaccine.
they've been used to study diseases, including measles, mumps, hiv, and ebola. we know that human cells have 46 chromosomes because a scientist working with heladiscovered a chemcial that makes chromosomes visible. hela cells themselves actually havearound 80 highly mutated chromosomes.
hela cells were the first to be cloned. they've traveled to outer space. telomerase, an enzyme that helps cancer cells evadedestruction by repairing their dna, was discovered first in hela cells. in an interesting turn of fate, thanks to hela, we know that cervicalcancer can be caused by a virus called hpv and now there's a vaccine. hela-fueled discoveries have filledthousands of scientific papers,
and that number is probably even higherthan anyone knows. hela cells are so resilient that they can travel on almost any surface: a lab worker's hand, a piece of dust, invading cultures of other cells and taking over like weeds, countless cures, patents and discoveriesall made thanks to henrieta lacks.
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