How does chemotherapy work? - Hyunsoo Joshua No

Prevodilac: Miloš Milosavljević Lektor: Milenka Okuka

During World War I, one of the horrors of trench warfare

Tokom Prvog svetskog rata, jedan od užasa rovovskog rata

was a poisonous yellow cloud called mustard gas.

bio je otrovni žuti gas zvani iperit.

For those unlucky enough to be exposed,

Kod onih manje srećnih koji su mu bili izloženi

it made the air impossible to breathe, burned their eyes,

izazivao je opstrukciju disanja, iritaciju očiju

and caused huge blisters on exposed skin.

i velike plikove na nepokrivenim delovima kože.

Scientists tried desperately to develop an antidote to this vicious weapon of war.

Naučnici su očajnički pokušavali da nađu protivotrov za ovo svirepo ratno oružje.

In the process they discovered the gas was irrevocably damaging the bone marrow

U tom procesu otkrili su da ovaj gas trajno oštećuje koštanu srž

of affected soldiers— halting its ability to make blood cells.

zaraženih vojnika, zaustavljajući njenu sposobnost pravljenja krvnih zrnaca.

Despite these awful effects, it gave scientists an idea.

Uprkos ovim užasnim posledicama, naučnici su došli na ideju.

Cancer cells share a characteristic with bone marrow: both replicate rapidly.

Ćelije raka dele zajedničku osobinu sa ćelijama koštane srži:

i jedne i druge se brzo repliciraju.

So could one of the atrocities of war

Pa su se zapitali da li bi ova ratna grozota

become a champion in the fight against cancer?

mogla postati pobednik u borbi protiv raka?

Researchers in the 1930s investigated this idea

Istraživači su 30-ih godina istraživali ovu ideju

by injecting compounds derived from mustard gas

tako što su intravenozno ubrizgavali jedinjenja dobijena iz iperita

into the veins of cancer patients.

pacijentima koji boluju od raka.

It took time and trial and error to find treatments that did more good than harm,

Trebalo im je dugo vremena i testiranja da bi pronašli lekove

koji proizvode više koristi nego štete,

but by the end of World War II,

ali pred kraj Drugog svetskog rata,

they discovered what became known as the first chemotherapy drugs.

otkrili su prve hemoterapijske lekove.

Today, there are more than 100.

Danas ih ima preko stotinu.

Chemotherapy drugs are delivered through pills and injections

Hemoterapijski lekovi se daju putem tableta i injekcija

and use "cytotoxic agents," which means compounds that are toxic to living cells.

i koriste „citotoksične agense”, tj. jedinjenja toksična za žive ćelije.

Essentially, these medicines cause some level of harm to all cells in the body—

U suštini, ovi lekovi imaju određene negativne efekte na sve ćelije u telu,

even healthy ones.

čak i na one zdrave.

But they reserve their most powerful effects for rapidly-dividing cells,

Ali najjači efekti su rezervisani za ćelije koje se brzo dele,

which is precisely the hallmark of cancer.

što je zaštitni znak kancera.

Take, for example, those first chemotherapy drugs,

Uzmimo, na primer, prve hemoterapijske lekove,

which are still used today and are called alkylating agents.

koji se i danas koriste i nazivaju se alkilirajući agensi.

They’re injected into the bloodstream,

Oni se ubrizgavaju u krvotok,

which delivers them to cells all over the body.

i tako dospevaju u ćelije svuda po telu.

Once inside, when the cell exposes its DNA in order to copy it,

Dospevši tamo, kad ćelija izloži svoj DNK da bi ga kopirala,

they damage the building blocks of DNA’s double helix structure,

oni oštećuju sastavne delove dvostruke spirale DNK,

which can lead to cell death unless the damage is repaired.

što dovodi do smrti ćelije ukoliko se oštećenje ne popravi.

Because cancer cells multiply rapidly,

S obzirom na to da se ćelije raka umnožavaju velikom brzinom,

they take in a high concentration of alkylating agents,

one primaju visoku koncentraciju alkilirajućih agenasa

and their DNA is frequently exposed and rarely repaired.

i njihova DNK je često izložena, a retko se popravlja.

So they die off more often than most other cells,

Tako da one izumiru češće nego većina drugih ćelija,

which have time to fix damaged DNA

koje imaju vremena da poprave oštećenu DNK

and don’t accumulate the same concentrations of alkylating agents.

i ne akumuliraju iste koncentracije alkilirajućih agenasa.

Another form of chemotherapy involves compounds called microtubule stabilizers.

Drugi oblik hemoterapije koristi jedinjenja zvana

mikrotubularni stabilizatori.

Cells have small tubes that assemble to help with cell division

Ćelije imaju male cevi koje se sklapaju kako bi pomogle u ćelijskoj deobi

and DNA replication, then break back down.

i replikaciji DNK, a onda se ponovo razdvajaju.

When microtubule stabilizers get inside a cell,

Kad mikrotubularni stabilizatori uđu u ćeliju,

they keep those tiny tubes from disassembling.

oni sprečavaju razdvajanje tih malih cevi.

That prevents the cell from completing its replication, leading to its death.

Time sprečavaju ćelije da dovrše replikaciju i one izumiru.

These are just two examples of the six classes of chemotherapy drugs

Ovo su samo dva primera od šest vrsta hemoterapijskih lekova

we use to treat cancer today.

koje danas koristimo u lečenju raka.

But despite its huge benefits, chemotherapy has one big disadvantage:

Uprkos ogromnim pozitivnim efektima, hemoterapija ima jedan veliki nedostatak:

it affects other healthy cells in the body that naturally have to renew rapidly.

ona pogađa druge zdrave ćelije u telu koje prirodno moraju brzo da se obnavljaju.

Hair follicles, the cells of the mouth, the gastrointestinal lining,

Folikuli kose, ćelije u ustima, gastrointestinalnom epitelu,

the reproductive system, and bone marrow are hit nearly as hard as cancer.

reproduktivnom sistemu i koštanoj srži pogođene su skoro istom jačinom kao i rak.

Similar to cancer cells, the rapid production of these normal cells

Slično ćelijama raka, brza proizvodnja ovih normalnih ćelija

means that they’re reaching for resources more frequently—

podrazumeva da one ćešće posežu za resursima

and are therefore more exposed to the effects of chemo drugs.

i prema tome su izloženije efektima hemoterapijskih lekova.

That leads to several common side effects of chemotherapy,

To dovodi do nekoliko nuspojava hemoterapije,

including hair loss, fatigue, infertility, nausea, and vomiting.

kao što su gubitak kose, umor, sterilitet, mučnina i povraćanje.

Doctors commonly prescribe options to help manage these side-effects,

Lekari obično prepisuju opcije za olakšavanje ovih nuspojava,

such as strong anti-nausea medications.

kao što su jaki lekovi protiv mučnine.

For hair loss, devices called cold caps can help lower the temperature

Za opadanje kose, „hladne kape” mogu sniziti temperaturu

around the head and constrict blood vessels,

na glavi i suziti krvne sudove,

limiting the amount of chemotherapy drugs that reach hair follicles.

smanjujući pritom dotok hemoterapijskih lekova u folikule kose.

And once a course of chemo treatment is over,

A po završetku hemoterapijskog lečenja,

the healthy tissues that’ve been badly affected by the drug will recover

zdravo tkivo oštećeno od lekova će se oporaviti

and begin to renew as usual.

i početi da se obnavlja kao i obično.

In 2018 alone, over 17 million people world-wide received a cancer diagnosis.

Samo u 2018, preko 17 miliona ljudi širom sveta je obolelo od raka.

But chemotherapy and other treatments have changed the outlook for so many.

Hemoterapija i drugi oblici lečenja mnogima su promenili izglede za oporavak.

Just take the fact that up to 95% of individuals with testicular cancer

Uzmimo samo činjenicu da je 95% osoba sa rakom testisa

survive it, thanks to advances in treatment.

preživelo, zahvaljujući napretku u načinima lečenja.

Even in people with acute myeloid leukemia— an aggressive blood cancer—

Čak i kod osoba sa akutnom mijeloidnom leukemijom, agresivnim oblikom raka krvi,

chemotherapy puts an estimated 60% of patients under 60

hemoterapija uvodi oko 60% pacijenata ispod 60 godina

into remission following their first phase of treatment.

u remisiju posle prve faze lečenja.

Researchers are still developing more precise interventions

Istraživači i dalje pronalaze još preciznije intervencije

that only target the intended cancer cells.

koje ciljaju samo ćelije raka.

That’ll help improve survival rates while leaving healthy tissues

To će podići procenat izlečenja pri čemu će zdrava tkiva

with reduced harm,

trpeti manju štetu

making one of the best tools we have in the fight against cancer even better.

i učiniti jedno od najboljih raspoloživih sredstava za borbu protiv raka

još boljim.