癌——来自远古的鼓声 - 沙龙区干细胞之家 - 中国干细胞行业门户第一站

干细胞之家 - 中国干细胞行业门户第一站 › 干细胞之家论坛 › 细胞与微环境 › 沙龙区 › 癌——来自远古的鼓声



免疫细胞治疗专区	欢迎关注干细胞微信公众号

返回列表

查看: 18843\|回复: 3	go 癌——来自远古的鼓声 [复制链接]

sunsong7

版主

Rank: 7 Rank: 7 Rank: 7

积分: 13286
威望: 13286
包包: 34831

论坛元老精华勋章金话筒优秀会员优秀版主

楼主

发表于 2011-5-21 00:19 |只看该作者 |倒序浏览 |打印

本帖最后由 sunsong7 于 2011-5-21 00:21 编辑

四十年前美国总统尼克松宣布“向癌症宣战”，尽管仅在美国就得到纳税人资助的研究高达1000亿美元，癌症的死亡率基本没有改变。数十个被制药厂大肆渲染的“能治愈癌症”药物要么无效或要么仅仅是边际效应....
7 m6 L- G+ a% Z% t. a' d
英国学者Paul Davies 指出：癌可能是远古生命形态在我们身体中的返祖重现?
在进化之初，原生代时期原始细胞聚集体的古老基因并没有消失，有一部分被纳入了更复杂生物体的基因组并潜伏在现代人类的身体中。这些基因至今仍在发挥重要的作用，在胚胎发育过程中以最基本和最古老的本能来铺设躯体的轮廓。3 g, ]$ ^7 p7 ~0 F" @

这个理论意味着，癌症细胞不是由遗传紊乱随机产生的、退化的粗野细胞，更像是有组织的步兵踩着远古的鼓点声朝向十亿年前的生活方式列队前行。当癌症在身体中前进,遗传工具箱中越来越多的祖先意志被焕发出来，按照进化故事逆向顺序呈现...
/ w9 n8 F! f$ l/ z6 ?7 J# t' M
根据这个结论，可以锁定远古工具箱中有限的特异基因，找到十分明确的治疗靶标。为了勾勒出癌返祖重现的全景图，不仅仅需要定位人类的基因组，还要定位包括植物、昆虫和真菌在内的共同远古多细胞祖先的基因组，推测不同的生命形式与癌故事情节的关系。如此将找到在生物进化道路上汇合点，并证明以往发育生物学和癌症生物学曾给出的的答案是撒谎，这个交汇处也不是单行道，通过研究癌症，生物学家会找出揭示复杂的生命现象的踪迹。& E, S6 h$ x. f! @! J0 d
4 a+ a# @9 i4 K1 Z T. i, D7 y
当其他许多疾病逐渐得到控制时，癌症却通过不同方式触动着每一个家庭，成为蔓延全球的头号杀手。虽然难以捉摸的“治愈”仍可能是一个遥远的梦想, 正确地理解癌的本质有助于更好地控制和减少它的威胁。' p0 c& w4 {2 v( V6 {' t( d( F

Cancer: The beat of an ancient drum?1 @7 C% w; z6 B7 s1 T, X5 D$ K: z

Paul Davies guardian.co.uk, Monday 25 April 2011 19.30 BST Article history

Colon cancer cells magnified to 2,000 times their size. Photograph: Micro Discovery/Corbis
9 Z( j5 g2 G- x$ r; Y' m! q
Forty years ago President Richard Nixon declared a “war on cancer”. Yet in spite of $100bn (£60bn) of taxpayer-funded research in the US alone, the cancer mortality rate remains little changed. Dozens of much-hyped “cures” developed by drug companies are either useless or have marginal effect. What can be done?. d  i4 ]- S) ^; b+ C. C  E
/ H! e. I; `  X, i1 y! W: ^' s8 G. O
Two years ago, in a spectacularly enlightened move, the US National Cancer Institute (NCI) decided to enlist the help of physical scientists. The idea was to bring fresh insights from disciplines like physics to help tackle cancer in radical new ways. Twelve research centres were created to focus the effort, and I was approached to run the one based at Arizona State University.

With no prior knowledge of cancer, I started asking some very basic questions. What struck me from the outset is that something as pervasive and stubborn as cancer must be a deep part of the story of life itself. Sure enough, cancer is found in almost all multicellular organisms, suggesting its origins stretch back hundreds of millions of years.
- O, J3 R& v9 u6 C# Q9 d( L6 M
Oncologists tend to think of cancer as a motley collection of cells gone berserk, but to me the way that tumours grow and spread to other organs indicates an organised and systematic strategy, designed to evade all that the body and the medical profession can throw at it. Such well-honed behaviour suggests they are the product of a long period of biological evolution.
" M) N3 @3 v- \" F# d# v: o& r% q
I began wondering whether cancer might be an evolutionary throwback to the dawn of multicellular life, when single cells began cooperating and forming rudimentary aggregations. Geologists trace this phase back to a time a billion or more years ago, during the so-called Proterozoic era, long before the appearance of plants and animals with their well-ordered body plans and fully differentiated cell types. The closest living analogue might be a sponge.

How, then, might these ancestral forms reappear today inside the bodies of animals? Evolution works by building on what came before. The genes needed to fashion the primitive cellular aggregates of the Proterozoic era did not all become defunct. Some were incorporated into the genomes of later, more sophisticated, organisms, and lurk inside human beings to this day. That’s because they still serve a crucial function. When an embryo develops, its genes lay down a body plan, starting with the most basic and most ancient features.  j* n3 q& ^" L) u2 f3 }
1 \+ L; e* L0 ?9 v
A century ago the German biologist Ernst Haekel pointed out that the stages of embryo development recapitulate the evolutionary history of the animal. Human embryos, for instance, develop, then lose, gills, webbed feet and rudimentary tails, reflecting their ancient aquatic life styles. The genes responsible for these features normally get silenced at a later stage of development, but sometimes the genetic control system malfunctions and babies get born with tails and other ancestral traits. Such anomalous features are called atavisms.

Charles Lineweaver of the Australian National University is, like me, a cosmologist and astrobiologist with a fascination for how cancer fits into the story of life on Earth. Together we developed the theory that cancer tumours are a type of atavism that appears in the adult form when something disrupts the silencing of ancestral genes. The reason that cancer deploys so many formidable survival traits in succession, is, we think, because the ancient genetic toolkit active in the earliest stages of embryogenesis gets switched back on, re-activating the Proterozoic developmental plan for building cell colonies. If you travelled in a time machine back one billion years, you would see many clumps of cells resembling modern cancer tumours.2 `% t: ]" w. Q  M( p  V7 w4 e
; Q* A' K7 I/ |0 k+ W
The implications of our theory, if correct, are profound. Rather than cancers being rogue cells degenerating randomly into genetic chaos, they are better regarded as organised footsoldiers marching to the beat of an ancient drum, recapitulating a billion-year-old lifestyle. As cancer progresses in the body, so more and more of the ancestral core within the genetic toolkit is activated, replaying evolution’s story in reverse sequence. And each step confers a more malignant trait, making the oncologist’s job harder./ I2 Y6 E) O9 }. N: T
; p( h. p6 Z6 s6 F! {- i4 s
There is some good news buried in this conclusion. The ancient toolkit will be a limited set of specific genes and therefore present a well-defined target for therapy. To build up a full picture of cancers as atavisms, we have to map not just the human genome but the genomes of our oldest common multi-celled ancestors, including those of plants, insects and fungi, and work out how the cancer story relates to these life forms too. It will be in the convergence of evolutionary biology, developmental biology and cancer biology that the answer to cancer will lie. Nor will this confluence be a one-way street. By studying cancer, biologists can gain clues about how complex life evolved on Earth, and maybe on other planets too.: O# k- N* S2 q6 {7 s9 y

Cancer touches every family in one way or another. As other diseases are brought under control, cancer is set to become the number one killer, and is already in epidemic proportions worldwide. Although the elusive “cure” may be a distant dream, understanding the true nature of cancer will enable it to be better controlled and less menacing.Forty years ago President Richard Nixon declared a “war on cancer”. Yet in spite of $100bn (£60bn) of taxpayer-funded research in the US alone, the cancer mortality rate remains little changed. Dozens of much-hyped “cures” developed by drug companies are either useless or have marginal effect. What can be done?. b3 q9 P8 V  b! f& i
; R) m  @- ~2 o4 B0 A' P: @! R
Two years ago, in a spectacularly enlightened move, the US National Cancer Institute (NCI) decided to enlist the help of physical scientists. The idea was to bring fresh insights from disciplines like physics to help tackle cancer in radical new ways. Twelve research centres were created to focus the effort, and I was approached to run the one based at Arizona State University.$ Z+ [- H2 b5 [

With no prior knowledge of cancer, I started asking some very basic questions. What struck me from the outset is that something as pervasive and stubborn as cancer must be a deep part of the story of life itself. Sure enough, cancer is found in almost all multicellular organisms, suggesting its origins stretch back hundreds of millions of years.+ H5 Z7 M# ^3 l' r2 s- E

Oncologists tend to think of cancer as a motley collection of cells gone berserk, but to me the way that tumours grow and spread to other organs indicates an organised and systematic strategy, designed to evade all that the body and the medical profession can throw at it. Such well-honed behaviour suggests they are the product of a long period of biological evolution.
/ \3 z$ n+ L: ^6 g' a
I began wondering whether cancer might be an evolutionary throwback to the dawn of multicellular life, when single cells began cooperating and forming rudimentary aggregations. Geologists trace this phase back to a time a billion or more years ago, during the so-called Proterozoic era, long before the appearance of plants and animals with their well-ordered body plans and fully differentiated cell types. The closest living analogue might be a sponge.2 J8 P" j+ d. ?

How, then, might these ancestral forms reappear today inside the bodies of animals? Evolution works by building on what came before. The genes needed to fashion the primitive cellular aggregates of the Proterozoic era did not all become defunct. Some were incorporated into the genomes of later, more sophisticated, organisms, and lurk inside human beings to this day. That’s because they still serve a crucial function. When an embryo develops, its genes lay down a body plan, starting with the most basic and most ancient features.& a6 i1 @) U5 Q& d; f

A century ago the German biologist Ernst Haekel pointed out that the stages of embryo development recapitulate the evolutionary history of the animal. Human embryos, for instance, develop, then lose, gills, webbed feet and rudimentary tails, reflecting their ancient aquatic life styles. The genes responsible for these features normally get silenced at a later stage of development, but sometimes the genetic control system malfunctions and babies get born with tails and other ancestral traits. Such anomalous features are called atavisms.
$ ^0 `2 X; a0 r0 o& E
Charles Lineweaver of the Australian National University is, like me, a cosmologist and astrobiologist with a fascination for how cancer fits into the story of life on Earth. Together we developed the theory that cancer tumours are a type of atavism that appears in the adult form when something disrupts the silencing of ancestral genes. The reason that cancer deploys so many formidable survival traits in succession, is, we think, because the ancient genetic toolkit active in the earliest stages of embryogenesis gets switched back on, re-activating the Proterozoic developmental plan for building cell colonies. If you travelled in a time machine back one billion years, you would see many clumps of cells resembling modern cancer tumours.

The implications of our theory, if correct, are profound. Rather than cancers being rogue cells degenerating randomly into genetic chaos, they are better regarded as organised footsoldiers marching to the beat of an ancient drum, recapitulating a billion-year-old lifestyle. As cancer progresses in the body, so more and more of the ancestral core within the genetic toolkit is activated, replaying evolution’s story in reverse sequence. And each step confers a more malignant trait, making the oncologist’s job harder.

There is some good news buried in this conclusion. The ancient toolkit will be a limited set of specific genes and therefore present a well-defined target for therapy. To build up a full picture of cancers as atavisms, we have to map not just the human genome but the genomes of our oldest common multi-celled ancestors, including those of plants, insects and fungi, and work out how the cancer story relates to these life forms too. It will be in the convergence of evolutionary biology, developmental biology and cancer biology that the answer to cancer will lie. Nor will this confluence be a one-way street. By studying cancer, biologists can gain clues about how complex life evolved on Earth, and maybe on other planets too.$ m5 Y, B1 v( w2 ~6 b; v8 {4 Z
8 b+ {) @' \& J" m& e. w! J& @% `
Cancer touches every family in one way or another. As other diseases are brought under control, cancer is set to become the number one killer, and is already in epidemic proportions worldwide. Although the elusive “cure” may be a distant dream, understanding the true nature of cancer will enable it to be better controlled and less menacing.
Via: Guardian. R# o$ u) O/ u& q# A! ?; ]* r