Cancer, why not eliminate

2,500 years ago, when ancient Greece physicians Hippocrates to malignant tumors are named καρκίνος (meaning crab or crayfish, English translation for cancer, Chinese translation for cancer) when is only visible to the patient's body surface a morphological description of the cancer:

malignant tumor typically stretches out from the Centre of mass to the surrounding branches, shaped like a crab. However, Hippocrates is impossible to know, more cases, cancer can occur in different tissues and organs of the human body, hidden deep in the body. So, in a sense, cancer is not a, but a general term for more than 100 kinds of diseases, but all these lesions have a characteristic in common: diseased cells proliferating out of body control, and unaware of these runaway cells invade other parts of the body

For thousands of years, humans to cancer etiology, pathology and treatment of study and reflection have never stopped. Until 20th century middle, scientists will cancer of occurred and human cell chromosome of exception contact up, eventually will cancer attributed to somatic genetic password of change--gene mutation, only let we human on cancer has has biology essentially of awareness: is gene mutation, let originally normal of cell out body within environment of control, wanton spread increased, as runaway Mustang, damage body normal of organization and organ.

However, we still want to go to the deeper question: why our genes are mutated, making the body's cells become cancerous, the human organism in the end suffer from terrible cancer?

In order to answer this question, here, I tried to explained to his audience the view: cells cancerous, long implant life deep in the most ancient and programs that cannot be deleted. From individual cell of angle,, gene mutation not they occurred cancer of reasons, but they occurred cancer of means and mechanism; gene mutation, also not cancer cell individual of Centerless of lost, but tens of millions of years to life evolution of select, is life evolution of source and product, is we life program in the not repair of system defects, so, we can such said: people somatic as long as continued to split and update, cancer will eventually became must.

To explore this question, we need to know about gene mutation in biological processes. Simply put, mutations in DNA sequences that are carriers of genetic information within a cell error change and the next cell to repair the errors of DNA sequences of final results. First, cell in split of when, DNA of copy process will has must of chances--although very low--occurred errors, led to new copy of DNA alkali base sequence and die version DNA sequence not match; also, cell survival environment in the of various factors, as UV, and smoking and other carcinogenic chemical material itself will directly led to DNA of injury, great increased has DNA sequence change of chances, serious of situation Xia even will caused cell chromosome of fracture, and restructuring and missing.

And the corresponding cells for DNA replication errors, and has a complete set of DNA damage response mechanisms. On one hand, the DNA copying machinery of the cell itself is equipped with a built-in error correction mechanism, capable of detecting errors occur, then the mismatch of bases deleted, replication from scratch; the other hand, when DNA due to the physical or chemical injury occurs when cells will start the appropriate program, DNA repair as possible intact. However, if the degree of DNA damage exceeds the cell can withstand the load cell apoptosis program launch suicide to remove cells with DNA damage. Long evolutionary process given 5 different eukaryotic cells DNA repair processes. We can imagine, the error correction mechanism of DNA replication and repair of the perfect mechanism in cells, typically mutation probability is very low. It is because of this reason, cancers are rare in young children, unless the cell growth environment, there are many factors that cause DNA damage and gene mutations induced by, for example, there are a lot of chemical carcinogens.

Now, we try to put this complex series of programs on the evolution of life in the long long survey. From cell to cell, prokaryotic to eukaryotic evolution, DNA replication and repair procedures, and cells respond to DNA damage mechanism is constantly improving, constantly improved. Cells evolve 5 different DNA repair mechanisms to cope with different triggers for different types of DNA damage. Eukaryotic cells form the components of this complex set of mechanisms – in collaboration with various features of protein than simple prokaryotic proteins within the cell parts are much more complex, much more precise. This process of constantly refining and improving itself, are the result of natural selection in the evolution of life long.

I think we should be able to understand, the unicellular organisms such as bacteria, which itself is a kind of "cancer" cells, with most essential characteristics of cancer cells: as long as the resources available in the environment, they can proliferate indefinitely.

Proliferation and at the same time, they are able to tolerate the emergence of a large number of mutations in the genome itself, rather like gene mutations cells in multicellular organisms is removed from the organism. Not only that, for them, rapidly dividing gene mutation and reproduction, is the continuation of the great advantages of species in different environments: they are forms that are resistant to different external conditions in the population of mutant cells. However, the sexually reproducing animals, it is difficult to tolerate such "black sheep" of the continued existence of, they need every cell of an individual to be able to carry out their duties and therefore requires a more

sophisticated mechanism of DNA replication and repair, DNA damage response as well as more complex mechanisms for the timely removal of these "black sheep", or individuals will die but not genes to the next generation. Therefore, the process evolved from the unicellular to multicellular organisms, for a single cell, is their "cancer" features--unlimited, rapid proliferation of potential-slowly is being suppressed by restrictions in Exchange for them to differentiate into various types of functional cells, multicellular organism to serve an individual's survival and reproduction process of this higher goal.

In this sense, human cells cancerous, both can be said to be "to divide" results, it can be said to be "evolutionary" process: they only go back to the primary stage of the evolution of life, to recover their repressed nature. Therefore, we can say that human cells cancerous, not the end of life evolved to the present day and results, but life remains in pristine condition in our body. Remains of this nature--genetic mutations, is the evolution of life can not get rid of.

Evolution does not offer advanced biological cell perfect DNA replication process also did not give the cells DNA repair of the perfect program, or even fix itself will almost inevitably these new DNA mutations. On one hand, this lack of pressure of natural selection. Biological evolution is never perfect, as long as you don't try to be run at the end and be eaten by the Lions caught up with one. Not only that, the perfect program would not only empower individuals need a survival advantage in the process of natural selection, but is likely to become a burden to them because, from a cost-benefit perspective, the benefits of reduced error rate (survival) and need to pay the cost (time and energy consumption) is not linear. A near-perfect interval, lowering the error rate from 1% to 0%, individuals have to pay will not only increase the cost of 1%.

But on the other hand, is the most fundamental aspect of evolution process of natural life requires the presence of genetic mutations. According to most people now accept the theory of evolution, the evolution of life to be possible, is one of the fundamental elements of gene mutation, is the only way to maintain the genetic diversity of a species, different individuals, species in the natural selection process has a higher chance of survival and reproduction. Therefore, the DNA replication process defects and fixes defects, evolution, the result of natural selection itself is life. Perfect DNA replication and repair procedures are destined to live in life evolution, natural selection in the game to win, because even if they appear in the evolution of individuals, spread, will only make the whole loss of genetic diversity of species, evolution of the source eventually dried up, must have caused the species ' natural selection at a disadvantage, the end result is being eliminated.

We can imagine life evolution selection will be in the costs and benefits to find a balance between, the goal is to make genes can be passed from generation to generation. Therefore, in single cell organism to multiple cells in the process of the evolution of higher organisms, mutations need to be effectively controlled, so that individuals can effectively breed if I die before I wake, or because of genetic mutations could not be made functional health of germ cells. This is why, in normal circumstances, our rare cancer in young people. But as said earlier, evolutionary mutation cannot be completely cleared from the system, which has long been embedded in each individual life millions of years of evolution, and the survival and reproduction of the species mix, mutually dependent. This is probably why cancer and other human diseases have a fundamentally different, it is tens of millions of years to evolve to stay in our body, "Devil", is the "disease of Kings". War of human cancer cells, is the evolution of the simple and complicated at the beginning of "self" contest between!

Lao Tzu: "misfortune of blessing, blessing, curse of the Volt. "Daduo·mukeji (Siddhartha Mukherjee) in his famous popular science books, the disease of Kings • cancer wrote in his biography:" cancer is one of our more perfect ' version '. Malignant growth, and growth at the genetic level are closely intertwined; to tell the two apart, may be the most important scientific challenges facing our species. " Due to mutations in the dual nature of the evolutionary process, both exclusion and lives to be dependent, and cells of cancer, will become inevitable.

Perhaps, said Gray's views inevitably creates the pessimistic mood, makes a man shrouded in the shadow of cancer, however, needs to be noted is that here the author mainly attempts to the evolution of life from the macroscopic point of view, in theory, discuss the necessity of carcinogenesis. However, when specific to each individual life, cancer will be subject to a variety of internal and external factors influence and strong health guardian--immune system of our body, in most cases in a timely manner to help us recognize and eliminate cancerous cells, the cancer killed in unknown. Plenty of scientific evidence that healthy lifestyle, can effectively prevent the occurrence of cancer, and we also expect to postpone it indefinitely if not exhausting pursuit of immortality, we just need to postpone the occurrence of cancer to go that day, isn't it?