What the sugar coating on your cells is trying to tell you | Carolyn Bertozzi

譯者: Lilian Chiu 審譯者: Helen Chang

This is a talk about sugar and cancer.

這是一場關於糖和癌症的演說。

I became interested in sugar when I was in college.

我在大學時對糖產生了興趣。

Not this kind of sugar.

不是這種糖。

It was the sugar that our biology professors taught us about

是生物學教授上課時教的那種糖，

in the context of the coating of your cells.

包裹著你的細胞的那種糖。

Maybe you didn't know that your cells are coated with sugar.

也許你不知道你的細胞 被糖所包裹著。

And I didn't know that, either,

我本來也不知道，

until I took these courses in college,

到大學時修了這些課程才學到。

but back then --

但是當時──

and this was in, let's just call it the 1980s --

那時是……我們姑且 就說是 1980 年代吧──

people didn't know much about why our cells are coated with sugar.

人們並不知道為什麼 我們的細胞會被糖所包裹。

And when I dug through my notes, what I noticed I had written down

而當我翻閱我的筆記時， 我發現我記下的是：

is that the sugar coating on our cells is like the sugar coating

細胞上所包裹的糖， 就像是花生 M&M 豆

on a peanut M and M.

外面的糖衣。

And people thought the sugar coating on our cells

人們認為，包裹著我們細胞的糖衣

was like a protective coating

就像是一層保護塗層，

that somehow made our cells stronger or tougher.

以某種方式讓我們的細胞 更強壯或更堅韌。

But we now know, many decades later,

但幾十年之後的現在，

that it's much more complicated than that,

我們知道答案並沒有這麼簡單，

and that the sugars on our cells are actually very complex.

包裹我們細胞的糖其實非常複雜。

And if you could shrink yourself down to a little miniature airplane

如果你把自己縮小成一架迷你飛機，

and fly right along the surface of your cells,

然後沿著你的細胞表面飛行，

it might look something like this --

你可能會看到這樣的景象──

with geographical features.

有著地理特徵。

And now, the complex sugars are these trees and bushes --

複雜的糖就像這些樹和灌木──

weeping willows that are swaying in the wind

隨風搖動、隨波移動

and moving with the waves.

的垂柳，

And when I started thinking about all these complex sugars

當我開始思考這些複雜的糖，

that are like this foliage on our cells,

它們就像是我們細胞上的葉子，

it became one of the most interesting problems that I encountered

對於我這個生物學家兼化學家來說，

as a biologist and also as a chemist.

它變成了我遇過最有趣的問題之一。

And so now we tend to think about the sugars

現在我們傾向將佈滿在

that are populating the surface of our cells

細胞的表面上的糖視為

as a language.

是一種語言。

They have a lot of information stored in their complex structures.

有大量的訊息儲存在 它們複雜的結構中。

But what are they trying to tell us?

但它們想要告訴我們什麼呢？

I can tell you that we do know some information

我可以告訴各位，我們確實知道一些

that comes from these sugars,

來自這些糖的訊息，

and it's turned out already to be incredibly important

且這些訊息對於醫學界的重要性

in the world of medicine.

也已經被證明。

For example, one thing your sugars are telling us

例如，你的糖能告訴 我們的其中一項資訊

is your blood type.

是你的血型。

So your blood cells, your red blood cells, are coated with sugars,

你的血細胞，你的紅血球細胞， 是被糖所包裹住的，

and the chemical structures of those sugars determine your blood type.

而這些糖的化學結構 決定了你的血型。

So for example, I know that I am blood type O.

比如，我知道我的血型是 O 型。

How many people are also blood type O?

有多少人也是 O 型？

Put your hands up.

請舉手。

It's a pretty common one,

這種血型很常見，

so when so few hands go up, either you're not paying attention

舉手的人這麼少， 若不是你們沒認真聽，

就是你們不知道自己的血型， 兩種情況都不太好。

or you don't know your blood type, and both of those are bad.

(Laughter)

（笑聲）

But for those of you who share the blood type O with me,

不過如果你和我一樣是 O 型，

what this means is that we have this chemical structure

這意味著我們的血細胞表面的

on the surface of our blood cells:

化學結構是這樣的：

three simple sugars linked together to make a more complex sugar.

三個單醣連在一起， 形成一個更複雜的糖。

And that, by definition, is blood type O.

這就是 O 型的定義。

Now, how many people are blood type A?

有多少人的血型是 A 型？

Right here.

在這裡。

That means you have an enzyme in your cells

這意味著你的細胞裡有一種酶，

that adds one more building block,

它會增加一塊積木，

that red sugar,

也就是那紅色糖，

to build a more complex structure.

來建立更複雜的結構。

And how many people are blood type B?

有多少人的血型是 B 型？

Quite a few.

還不少。

You have a slightly different enzyme than the A people,

你們的酶和 A 型的人略有不同，

so you build a slightly different structure,

所以建出來的結構也略有不同，

and those of you that are AB

至於 AB 型的人，

have the enzyme from your mother, the other enzyme from your father,

則有分別來自母親和父親的酶，

and now you make both of these structures in roughly equal proportions.

你所建立的這兩種結構， 在比例上是大約各半。

And when this was figured out,

直到上個世紀，這個現象

which is now back in the previous century,

才被發現，

this enabled one of the most important medical procedures in the world,

因為它，才會有世界上 最重要的醫療手術之一，

which, of course, is the blood transfusion.

當然，也就是輸血。

And by knowing what your blood type is,

知道了自己的血型，

we can make sure, if you ever need a transfusion,

當你需要輸血時，我們就可以確保

that your donor has the same blood type,

你的捐血者和你有同樣的血型，

so that your body doesn't see foreign sugars,

這樣你的身體才不會發現 有外來的糖進入，

which it wouldn't like and would certainly reject.

它不喜歡外來的糖，一定會排斥。

What else are the sugars on the surface of your cells trying to tell us?

你細胞表面的糖， 還能告訴我們什麼資訊？

Well, those sugars might be telling us that you have cancer.

那些糖還可能還可以 告訴我們你得了癌症。

So a few decades ago,

幾十年前，

correlations began to emerge from the analysis of tumor tissue.

針對腫瘤組織所做的分析， 開始發現了相關性。

And the typical scenario is a patient would have a tumor detected,

最典型的情況是： 當一名患者被檢測出腫瘤，

and the tissue would be removed in a biopsy procedure

會進行活組織切片來切除組織，

and then sent down to a pathology lab

該組織接著會被送到病理實驗室，

where that tissue would be analyzed to look for chemical changes

在那裡進行分析，尋找化學變化，

that might inform the oncologist about the best course of treatment.

這些變化或許能幫助 腫瘤學家斷定最適合的療程。

And what was discovered from studies like that

這類研究的發現是，

is that the sugars have changed

當細胞由健康轉成病態時，

when the cell transforms from being healthy to being sick.

糖也會發生變化。

And those correlations have come up again and again and again.

而這些相關性一而再、 再而三地出現。

But a big question in the field has been: Why?

但實做上的一個大問題是：為什麼？

Why do cancers have different sugars? What's the importance of that?

為何癌症會有不同的糖？ 其重要性何在？

Why does it happen, and what can we do about it if it does turn out

它為何發生？

若它真的和疾病的進程有關， 我們又能做什麼呢？

to be related to the disease process?

So, one of the changes that we study

我們所研究的各項變化之一，

is an increase in the density of a particular sugar

就是一種特定糖的密度增加，

that's called sialic acid.

這種糖叫「唾液酸」。

And I think this is going to be one of the most important sugars

我認為它將是我們這個時代

最重要的糖其中的一種，

of our times,

so I would encourage everybody to get familiar with this word.

所以我建議大家都熟悉一下這個詞。

Sialic acid is not the kind of sugar that we eat.

唾液酸不是我們吃的那種糖。

Those are different sugars.

那些是不同的糖。

This is a kind of sugar that is actually found

實際上，在你體內的所有細胞上，

at certain levels on all of the cells in your body.

都可找到一定量的這種糖。

It's actually quite common on your cells.

它在你的細胞上其實很常見。

But for some reason,

但由於某種原因，

cancer cells, at least in a successful, progressive disease,

癌細胞……至少在疾病 成功進展的情況下，

tend to have more sialic acid

癌細胞的唾液酸量通常會多於

than a normal, healthy cell would have.

正常健康細胞的唾液酸量。

And why?

為什麼呢？

What does that mean?

這意味著什麼？

Well, what we've learned

我們所知道的是，

is that it has to do with your immune system.

這和你的免疫系統有關。

So let me tell you a little bit about the importance of your immune system

所以，讓我先告訴各位 免疫系統在癌症中的重要性。

in cancer.

And this is something that's, I think, in the news a lot these days.

我想，這陣子在新聞中 也有不少相關報導。

You know, people are starting to become familiar with the term

人們開始越來越熟悉這個詞：

"cancer immune therapy."

「癌症免疫治療」。

And some of you might even know people

甚至在座可能就有人認識

who are benefiting from these very new ways of treating cancer.

這些新式癌症療法的受益者。

What we now know is that your immune cells,

我們現在知道，你的免疫細胞，

which are the white blood cells coursing through your bloodstream,

也就是在你血液中 流動的白血球細胞，

protect you on a daily basis from things gone bad --

每天保護著你，避免壞事發生──

including cancer.

包括癌症。

And so in this picture,

在這張圖片中，

those little green balls are your immune cells,

這些綠色的球體就是你的免疫細胞，

and that big pink cell is a cancer cell.

而那個粉紅色大細胞則是個癌細胞。

And these immune cells go around and taste all the cells in your body.

這些免疫細胞四處巡邏， 品嚐你體內的所有細胞。

That's their job.

那是它們的職責。

And most of the time, the cells taste OK.

大多數情況下，細胞嚐起來沒問題。

But once in a while, a cell might taste bad.

但偶爾，某個細胞 可能嚐起來不太對。

Hopefully, that's the cancer cell,

但願那就是癌細胞，

and when those immune cells get the bad taste,

當這些免疫細胞嚐到不對的味道，

they launch an all-out strike and kill those cells.

它們會傾巢而出，殺死這些細胞。

So we know that.

我們知道這些。

We also know that if you can potentiate that tasting,

我們也知道，如果你能 賦與那種品嚐行為力量，

if you can encourage those immune cells to actually take a big old bite

如果你能鼓勵那些免疫細胞狠狠地咬

out of a cancer cell,

癌細胞一大口，

you get a better job protecting yourself from cancer every day

你每天就更能保護自己免於癌症，

and maybe even curing a cancer.

甚至還可能治癒癌症。

And there are now a couple of drugs out there in the market

目前市面上有幾種用來

that are used to treat cancer patients

治療癌症病人的藥，

that act exactly by this process.

正是利用這個過程來產生作用。

They activate the immune system

它們會活化免疫系統，

so that the immune system can be more vigorous

讓免疫系統更強而有力，

in protecting us from cancer.

保護我們免於癌症。

In fact, one of those drugs

事實上，這些藥物的其中一種，

may well have spared President Jimmy Carter's life.

很可能救了總統吉米卡特的命。

Do you remember, President Carter had malignant melanoma

記得嗎，卡特總統 得了惡性黑色素瘤，

that had metastasized to his brain,

癌細胞轉移到他的腦部，

and that diagnosis is one that is usually accompanied by numbers

那種診斷通常還會帶著一個數字，

like "months to live."

「剩幾個月可活」。

But he was treated with one of these new immune-stimulating drugs,

但是他接受了一種 免疫系統刺激藥物的治療，

and now his melanoma appears to be in remission,

現在他的黑色素瘤顯然已經緩解，

which is remarkable,

這結果很了不起，

considering the situation only a few years ago.

畢竟他幾年前的狀況還是非常糟的。

In fact, it's so remarkable

事實上，這結果了不起到

that provocative statements like this one:

引發了這段陳述：

"Cancer is having a penicillin moment," people are saying,

「癌症也有了盤尼西林的時刻」，

人們對於這些新的 免疫治療藥物如是說。

with these new immune therapy drugs.

I mean, that's an incredibly bold thing to say about a disease

用這樣的方式形容一種我們長年對抗

which we've been fighting for a long time

且通常都打不贏的疾病，

and mostly losing the battle with.

是相當大膽的。

So this is very exciting.

所以這很讓人興奮。

Now what does this have to do with sugars?

那麼，這與糖有什麼關係呢？

Well, I'll tell you what we've learned.

讓我告訴各位我們目前所知道的。

When an immune cell snuggles up against a cancer cell to take a taste,

當一個免疫細胞靠向一個 癌細胞，去品嚐它的味道時，

it's looking for signs of disease,

它是在尋找疾病的徵兆，

and if it finds those signs,

如果它能找到這種徵兆，

the cell gets activated and it launches a missile strike and kills the cell.

這細胞就會被活化， 發動飛彈攻擊，殺死癌細胞。

But if that cancer cell has a dense forest of that sugar, sialic acid,

但若癌細胞上覆蓋了一層由那種糖， 也就是唾液酸，所組成的茂密樹林，

well, it starts to taste pretty good.

那它嚐起來的味道就會是好的。

And there's a protein on immune cells that grabs the sialic acid,

在免疫細胞上有個蛋白質 會抓住唾液酸，

and if that protein gets held at that synapse

如果那蛋白質被卡在免疫細胞

between the immune cell and the cancer cell,

和癌症細胞之間的突觸上，

it puts that immune cell to sleep.

就會讓免疫細胞進入睡眠。

The sialic acids are telling the immune cell,

如果唾液酸告訴免疫細胞說：

"Hey, this cell's all right. Nothing to see here, move along.

「嘿，這個細胞沒問題。 沒什麼好看的，走開。

Look somewhere else."

去看其他地方。」

So in other words,

換言之，

as long as our cells are wearing a thick coat of sialic acid,

只要我們的細胞覆蓋著 很厚一層的唾液酸，

they look fabulous, right?

它們看起來就很好，對嗎？

It's amazing.

那很驚人。

And what if you could strip off that coat

如果你能夠剝除包裹的外層，

and take that sugar away?

把糖給去除掉呢？

Well, your immune system

那麼，你的免疫系統

might be able to see that cancer cell for what it really is:

就有可能看見癌症細胞的真面目：

something that needs to be destroyed.

該被摧毀的目標。

And so this is what we're doing in my lab.

我們在我的實驗室中就在做這個。

We're developing new medicines

我們正在開發新的藥，

that are basically cell-surface lawnmowers --

基本上可以說是 細胞表面用的除草機，

molecules that go down to the surface of these cancer cells

分子會前往這些癌症細胞的表面，

and just cut off those sialic acids,

把那些唾液酸通通除掉，

so that the immune system can reach its full potential

這麼一來，免疫系統就能發揮全力，

in eliminating those cancer cells from our body.

消滅掉我們身體中的癌症細胞。

So in closing,

最後結尾，

let me just remind you again:

讓我再次提醒各位：

your cells are coated with sugars.

你們的細胞都被糖所包裹著。

The sugars are telling cells around that cell

糖會告訴那細胞附近的其他細胞

whether the cell is good or bad.

那細胞是好的或是壞的。

And that's important,

那很重要，

because our immune system needs to leave the good cells alone.

因為我們的免疫系統 得要放過好的細胞。

Otherwise, we'd have autoimmune diseases.

不然我們就會有自體免疫疾病了。

But once in a while, cancers get the ability

但偶爾，癌症有能力可以

to express these new sugars.

展現出這些新的糖。

And now that we understand

現在我們知道

how those sugars mesmerize the immune system,

那些糖是如何迷惑免疫系統的，

we can come up with new medicines to wake up those immune cells,

我們就能做出新的藥 來喚醒那些免疫細胞，

tell them, "Ignore the sugars, eat the cell

告訴它們：「別理會那些糖， 去吃那細胞，

and have a delicious snack, on cancer."

在癌症上面吃頓美味的點心。」

Thank you.

謝謝大家。

(Applause)

（掌聲）