Not eighty years, not eighty days, as long as eight days, the cancer cells will basically not grow any longer, and you will even see a lot of dead cells floating in the culture medium. Wait a minute, I read few books, but I know that cancer cells are immortal cells. How can they die so soon? So first, let us briefly understand cancer cells. Different from normal cells, cancer cells have three basic characteristics: immortality, migration, and loss of contact inhibition. The immortality mentioned here does not mean that cancer cells cannot be killed even if they have golden bells and iron shirts. It means that under suitable conditions, cancer cells can proliferate indefinitely. Normal cells have a certain life span. Most cells will stop dividing and enter the senescence phase or apoptosis after 40-60 divisions. This phenomenon is called the Hayflick Limit (Hayflick Limit). But the Hayflick limit does not apply to cancer cells. Cancer cells can divide forever, which gives a sense of immortality. But as mentioned before, only under the right conditions can cancer cells survive. And this suitable condition includes adequate nutrition. Regardless of whether the cancer cells are round and fat, they can’t survive without eating enough. Although the subject has given a condition to continuously provide nutrients, we still have to consider the actual situation. In the laboratory, cells are mostly in petri dishes/flasks. This also means that the cell growth space is limited. Will the cancer cells grow into a culture flask? will not. Speaking of this, we have to mention the third characteristic of cancer cells, the loss of contact inhibition. The so-called contact inhibition means that when cells are in contact with each other, they stop growing. That is to say, when they cover the culture flasks and put each other’s breasts on their backs, the cells will not grow. But cancer cells don’t. They lose contact inhibition and can continue to grow even if the front chest is attached to the back. What if I run out of space horizontally? Let it be long! So when the cancer cells are covered with a layer in the culture flask, they start to grow up the second and third layers… But this also brings a problem. When the number of layers increases, the cells in the bottom layer will also grow up. It becomes more and more difficult to get nutrients and oxygen, and even only the excrement and carbon dioxide from the upper cells. When the underlying cells die due to lack of nutrients and oxygen, the original multi-layered cell cluster is also lysed. Therefore, in a limited culture flask, even if sufficient nutrients are ensured, cancer cells will not grow indefinitely. Since cancer cells can’t grow up even in a culture bottle, why can some tumors grow so big? Because tumors are not only cancer cells, but also somatic cells, extracellular matrix, and most importantly capillaries. These can help the transportation of oxygen and nutrients, allowing cancer cells to thrive. Regardless of actual factors, assuming we have an infinite cell culture flask, how big a cancer cell can grow in 80 years? Take the common breast cancer cell MCF-7 as an example. The doubling time of MCF-7 is 24 hours, which means that the total number of cells doubles every 24 hours. It takes approximately 23.3 x 10⁶ cells to grow a 175cm² culture flask. If we plant 10⁵ cells on the first day, it will be full in exactly eight days. One month later, there will be 460 square meters, and 65 days later, it will be more than 10 million square kilometers, which is bigger than a single China. If it continues to increase exponentially, it will not be 80 years. My calculator will no longer work after more than 300 days (dog head)


By zhiwo

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6 months ago

Depending on the type of cancer cells, the time can range from a few days to a few weeks. It is nothing more than overgrowing the petri dish, and then the condition is not good, and then all the cells hang up. Will not grow to a meat ball bigger than the earth! Under laboratory conditions, it is difficult for cells and even tissues to form, let alone organs. Certain cancer cells may stack together to form cell clumps, but without blood vessels to transport nutrients, the cells inside are difficult to absorb nutrients and eventually hang up. The waste released by the hanged cells cannot be discharged, causing the surrounding cells to hang up. , And eventually all cancer cells will die. Although most cancer cells secrete angiogenic factors, they do not grow blood vessels because there are no capillaries or endothelial cells. And even if blood vessels can grow, because the cardiovascular system is a system, without a heart, blood vessels are useless. Therefore, if the cancer cells are not passaged on time, the cells will die! Many people in the comments mentioned that external sources can access blood vessels so that the inside of the tumor can also get nutrients, so that the tumor can continue to grow. But in reality, this method is not ideal. First of all, blood vessels are not enough. Blood pressure is needed to enable cells to absorb nutrients and discharge waste. This requires a heart or a pump to form a circulatory system. Secondly, the tumor cells are too dense, and it is difficult for blood vessels to penetrate deep into the tumor. Most tumors are hard to the touch, because the tumor cells are arranged very tightly, and it is difficult for capillaries to grow in the tumor tissue. In the human body, at the end of the tumor, internal erosion will begin, because the internal blood vessels cannot penetrate deeply, and cell nutrition and metabolism cannot proceed normally, resulting in a large area of ​​cell death. Therefore, culturing cancer cells in vitro, even in 3D culture, is difficult to solve the problem that blood vessels cannot penetrate the tumor tissue and prevent tumor tissue necrosis. In addition, embolization of blood vessels in tumor tissues can cause tumor cells to die due to insufficient nutrition. But cancer cells will metastasize. This is where the cancer is most terrible! Moreover, the destruction of tumor tissues often accelerates the spread of tumor cells, so necrotic tumors are more deadly than intact tumors!

Last edited 6 months ago by heloword
6 months ago

This problem is easy to distinguish between professionals and amateurs at once (after growing cells, I seem to have returned to the difficult years of being dominated by cells). Because many people only know the infinite proliferation ability of cancer cells, but ignore this ability is a prerequisite. It must be: the body is supplied by blood vessels. But in vitro, cancer cells will not proliferate indefinitely, as everyone who has raised cancer cells knows. I remember that when I was growing the cells, if I did not change the medium in time, the cells would die in batches soon. Even if the liquid is changed, if the plate becomes full, it will die. why? First, cancer cells cannot form a three-dimensional structure outside the body. Many people think that cancer cells in the body form tumors, but they mistakenly think that they also form tumors outside the body. This is totally different. Generally, academics say that cancer cells will not have contact inhibition, so they can grow indefinitely. However, in reality, it has been found that solid tumor cells will basically not grow after they are full, nor will they pile together, but start to die. The reason is that cancer cells are still very smart. They secrete some signal proteins. When these signals reach a certain density, the cancer cells stop growing, even if you supply nutrients. Second, 3D culture can’t solve this problem. Some people may think, since the level is inhibited, how about allowing cancer cells to get up and down space? In fact, there are already various 3D methods for culturing cancer cells. Unfortunately, cancer cells still cannot grow indefinitely. The reason lies in the lack of nutrients inside the cancer cells. With the dense growth of cancer cells, if a three-dimensional structure is formed, the cancer cells on the surface can get enough oxygen and nutrients, but the cancer cells inside are miserable. They can’t grab oxygen and nutrients at all. As a result, the internal cancer cells can live. Don’t go down and start to die. Some people may wonder, why are cancer cells in the body OK? This is because cancer cells in the body can grow blood vessels, but not outside the body. why not? Because the cell types are different. Blood vessels need endothelial cells to grow, and cancer cells, such as breast cancer cells, are breast cells, not the same type of cells. (In fact, there is a large class of anti-cancer drugs that target tumor blood vessels. The nutrition of tumors is typically VEGF/VEGFR drugs. There are many kinds of drugs.) If you want to evacuate the cells and finally provide nutrients to the inside, that is What is the difference between a cell culture and a plate of loose sand? Next comes an important topic, since cancer cells cannot grow indefinitely outside of the body, why are there so many cancer cell lines in the world? For example, what about cell lines such as HeLa cell (cervical cancer) MCF 7 (breast cancer)? Even the HeLa cell line is almost 70 years old, right? The answer is that scientists are not a type of stupid people and a lot of money. First, we can train them separately. For example, when a plate is almost full, it will be divided into two, and then continue to be cultured, so as to keep dividing, there is no need to worry that the cancer cells on a plate will grow up and eventually die, so the whole world can be cultured endlessly. Some people may say, if this is the case, wouldn’t it be exhausting, keep dividing and dividing, not to spend money, if one day is busy and tired, and forget how to break it. It’s ok. Second, we can also freeze them. One big advantage of the cells is that they can be frozen and preserved. If you don’t want to do it, just collect the cancer cells and throw them in liquid nitrogen for preservation. When the cancer cells are needed someday, they can be taken out and resuscitated. The ability of frozen cells to be preserved is still inconclusive, and some people even think that it can be permanent. By the way, in fact, cancer cells are not easy to raise. With that mindset, it is easier to raise bacteria. Think about the harsh environment of bacteria. Everyone can raise yeast, but it is like raising cells to become a dog every day.

6 months ago

meeting. . Become a pool of smelly water. Many people think of HeLa cells when they see this problem. Over the decades, it is said that HeLa cells have grown to a number of thousands of tons. But in fact, in a laboratory, if a cancer cell is continuously supplied with nutrients, if it is not passaged, what you will get in the end is a pool of smelly water. (Biological dogs that have failed to pass down can come over and complain about it). Of course, if you consider the ideal situation, unlimited space, unlimited nutrients, and there are no conditions that inhibit cancer cell division, we will count it 80 years later. HeLa cell division cycle is about 20 hours, let’s estimate it based on 24 hours. In 80 years, it can split 29200 times, which is 2^(29200-1) on the 82nd day, which is about 2^81, 2.4178516392292583e+24. What is this concept? The human body contains about 40-60. Trillions of cells, that is, 14 zeros behind one. The total number of human beings in the world is calculated at 7 billion. The total number of cells is about 2.8e+24, which is about 24 0 after 2.8. That is, when this cell divides to 82 days, it has equaled the total volume of all the world’s population. At about the 101st day, it is about 2^100, 1.2676506002282294e+30, and there are 30 zeros behind the 1. In other words, the total number of humans has increased by 100,000 times, and the level of e30 is probably guessed. On the 1001th day, that is, less than 3 years, there are as many as 300 zeros behind about 2^1000. It is estimated that it has broken through the earth, entered the solar system, and even the solar system cannot be suppressed. Then 80 years later, the power of 2^(29200-1) has really broken through my imagination. Will it encroach on the entire known universe? Don’t dare to write like that if you swallow the starry sky.

6 months ago

Xie Jiao, I’m in the laboratory, just out of the cell room. After reading most of the answers, everyone seems to be discussing 2D cell culture based on petri dishes. 2020 is about to pass. Cancer cell culture does not discuss 3D culture. Is it worthy of the biological era of the 21st century? (Come on manually, 3D culture cancer cell balls to understand! What is 3D cell culture? Traditional 2D culture is equivalent So the cells are laid flat on a petri dish. However, this culture method is naturally different from the growth environment of the cells in the body: first, the material of the petri dish is much harder than most human tissues; second, Most cells in the body are also in a three-dimensional space instead of a two-dimensional space flat on a petri dish. Therefore, in order to simulate the growth environment of cells in vivo in vitro, 3D cell culture emerged. In 3D cell culture , Cells are wrapped in a material called hydrogel (a bit like jelly). Such colloidal materials often have hardness and chemical composition similar to human tissues, and therefore better mimic the environment in the body. What about cancer cells in 3D culture? When ordinary cells such as human skin fibroblasts are cultured in 3D, their morphology will not change much. It is nothing more than the spreading area of ​​the cells. Different. But the cancer cells are different. When this group of cells were cultured in 3D in hydrogel, they turned out to look like tumors! These cancer cells reunite in three-dimensional space, holding hands, and continue to grow. , Becomes a cancer spheroid, like a tumor. The difference between 2D and 3D culture of cancer cells (Source: Journal of Cell Science (2017) 130, 203-218 doi:10.1242/jcs .188102) If we keep growing in 3D, what will happen to these cancer cell balls? In a 3D environment, the size of a cancer cell is about 20-25 microns. When we wrap a cancer cell in a 3D environment, About the fifth and sixth day, you can see a cancer cell ball about 50-60 microns. By the fifteenth day, the cancer cell can grow to nearly 100 microns. However, this cancer cell ball will be like this. Does it continue to grow wildly? Unfortunately, although cancer cells can multiply indefinitely, when they are cultured in vitro, without the assistance of blood vessels and other cells, the cancer cells are still a lot weaker. Generally, the cell spheres are as large as 500 microns. If it gets bigger, it will crack! This is because as the cancer cell ball grows larger, it is more difficult for the cells in the nucleus to get nutrients. When cultured in vitro, all nutrients are passed through the most. Simple spreading method transports cancer cells from the outside to the inside. Therefore, for these cancer cell balls, they often form a growing shell and a dead inner core. In fact, it is a paper tiger that is strong in the outside and dry in the middle. > Cancer cell balls often have a multiplying shell, a static middle layer, and a dead core. (Image source: Sant S, Johnston PA. The producti on of 3D tumor spheroids for cancer drug discovery. Drug Discovery today. Technologies. 2017 Mar;23:27-36. DOI: 10.1016/j.ddtec.2017.03.002.) So the wait is less than eighty years, about one month At that time, the more dead cancer cells in the inner core accumulate, the more difficult it is to maintain such a three-dimensional spherical structure. So in the end, the once incomparable cancer cell ball, they still cracked. Finally, a digression, compared to the immortality of cancer cells indefinitely multiplying, it is his migration that is more deadly.

6 months ago

As a scientific research dog, the most often heard sorrow from the heart in the laboratory is probably “God! My cells are dead again”! Therefore, in less than 80 years, 8 weeks later, the cancer cell in the question has passed away. If it is a little bit unlucky, it may not live for 8 days. Yes, cancer cells can indeed grow indefinitely, but this kind of “infinite” has a prerequisite, and only nutrients are far from enough. The occurrence of tumors is a complex multi-step process. If normal cells want to transform into cancer cells, they must compete with their host (that is, our body). When the initial cancer cell transformation encounters a bottleneck, its ultimate survival depends on its ability to find a favorable environment and its ability to settle in that environment. Not only is a complex tumor microenvironment (TME) involved here, the generation of this ability also depends on a more complex system, the “tumor ecosystem”. The occurrence of tumors is closely related to the physiological state of TME. The high degree of heterogeneity and complexity of TME of an advanced solid tumor can be described as amazing (Figure 1). In simple terms, TEM consists of extracellular matrix, stromal cells (such as fibroblasts, mesenchymal stromal cells, pericytes, and occasionally fat cells, blood and lymphatic network) and immune cells (including T lymphocytes, B lymphocytes) Cells, natural killer cells and tumor-associated macrophages). In addition, exosomes also play an important role in the paracrine and autocrine communication between TEM cells and the transformation of normal cells near TME into tumor cells. The rapid growth of tumor cells induces angiogenesis and subsequently forms the chaotic branch structure of TME. The development of tumors is highly dependent on specific TME. TME has a great influence on the prognosis of cancer treatment and affects the effect of chemotherapy [1]. Tumor microenvironment anatomy and a more complex tumor ecosystem is a diverse community in which tumor cells can interact with other tumor cells and host cells in their microenvironment, and can adapt to the ever-changing environment through evolution. The ecosystem around the tumor not only promotes the growth of cancer cells, but also provides them with a safe “home” to overcome the attack of the immune system. In the process of tumorigenesis, different cancer cells with genetic heterogeneity gradually appear, evolve, and interact with cells in the tumor microenvironment, leading to hijacked host metabolism, immune evasion, metastasis, and ultimately death [2 ]. Tumors are composed of a variety of cells. Tumor cells in different regions can represent the heterogeneity of the tumor ecosystem and constitute different tumor, mesenchymal, and immune cell types. There is a continuous competitive relationship between the immune system and transformed cells, which is an important reason for tumor cell death or survival. A favorable tumor ecosystem will help malignant cells survive under nutritional deficiencies and immune selective pressures. In addition, the heterogeneity of tumor ecosystem cells such as tumor-associated macrophages (TAM), endothelial cells (EC) and immune cells can further affect clinical treatment response [3]. In this way, it is no exaggeration to say that there is no cancer cell in the body that can survive on its own, but it is really a clever and shameless “parasite”. Let us return to the topic. The culture of cancer cells in the laboratory mainly relies on traditional 2D culture technology. With the support of the culture medium, it can only achieve pure physical contact between cells, which is not in the true sense. The environment in which the tumor is located is limited by the source of cells, and its fidelity and differentiation ability are low. Therefore, long-term culture, even if the nutrition is sufficient, at the exponential growth rate of cancer cells, if the number of cells is not reduced or replaced with larger containers for the passage of cells, this cancer cell will inevitably appear “cell state is not good”. . Let me ask, in 80 years, how big a container should I use to pack it? Of course, it is worth mentioning that a new culture technology that is currently under development-organoid technology. Organoids are three-dimensional cell complexes that are similar in structure and function to target organs or tissues, formed by inducing differentiation of stem cells or organ progenitor cells using 3D culture technology in vitro. They have stable phenotypic and genetic characteristics and can be used in Long-term culture in vitro, it reproduces the two events of internal organs in the process of formation, namely, the classification and aggregation of similar cells in the way of adhesion and spatial specific cell lineage stereotypes [4]. One day when we can successfully simulate the perfect tumor ecosystem in the body in vitro, 80 years may become a reality.

6 months ago

About twenty years ago, it was popular to breed an interesting fungus. My name is “Three Strains”. It is placed in any container. The appearance is a bit similar to silica gel or jelly. It is a thing to pour some sugar water regularly. The child will grow up, so when you want to eat it, peel off the top layer and eat it. Cancer cells are also similar. In fact, this horrible thing is already a kind of single-celled organism. After decades of continuous nutrition input, you can get a big lump of meat.

6 months ago

Tumor cells don’t have the ability to differentiate into the circulatory system in vitro, so even if the nutrition is unlimited, if they don’t pass through the flasks on time, they will grow into a lump, and the cells inside will starve to death.
In the human body, tumors can induce blood vessel growth, so they can grow very large. Even so, tumors often die inside.

6 months ago

Explicitly oppose the so-called “the total amount of HeLa cell line exceeds 50 million tons”. The total mass of human beings is less than 400 million tons. The global annual output of pork is 120 million tons. Global cereal production is less than 700 million tons. (Probably) It means that there are more than one-eighth of the total mass of human cells on the earth, cultivated in laboratories and vaccine factories? Why do humans need so many human cancer cells? If humans are really in the laboratory The environment has cultivated human cancer cells with more than one-eighth of the total mass of humans, so the resource cost required may not be enough for the world’s gdp. This tm is not for pigs. It is equivalent to building a Great Wall with tweezers and digging into the Pacific Ocean with an ear pick. Don’t talk about exponential growth, exponential growth will only have a huge order of magnitude under uncontrollable conditions. And laboratory cultivation must be under controllable conditions. After the experiment is completed, a small part of the next generation will be cultivated, and most of them will definitely be destroyed. In other words, the so-called HeLa cell division exponential growth will only continue to circulate in the first few levels (from a mathematical point of view), and there will be no explosive growth at all.

6 months ago

Peto’s paradox has an explanation, that is, the super-tumor theory is simply the inner ghost theory (actually no!) If a cancer cell continues to proliferate, then it will eventually form a tumor (an aggregate of cancer cells) that transports nutrients. Blood vessels are needed. Let’s talk about cancer cells later. They have genetic instability, so they can continue to mutate during proliferation, and even some of the cancer cells can mutate faster than itself. After a certain period of time, a certain number of times have passed. Divided cancer cells may also think that they are a new individual and stop cooperating. In other words, the original tumor tissue will suddenly become an enemy who snatches the same nutrients and living space. This is the prototype of a super tumor. Remember before As I said, do cancer cells need blood vessels to transport nutrients? Ultra-tumor not only rushes to the primary cancer cells, it also cuts off your blood vessels that transport nutrients, which will cause the primary cancer cells to die in pieces. What’s even more frightening is that (for primary cancer cells), this process can continue continuously. Tumor super-tumor super-tumor super-tumor super-tumor…This is also a reason why cancer cells cannot proliferate indefinitely.

6 months ago

Cancer cells that reproduce fast reproduce every 10 hours. We conservatively estimate that they reproduce every 24 hours. Then, after 80 years, there will be 29200 days in total, which means there will be 2 to the 29200th power of cells. You know, the universe The total number of atoms in is only 10 to the 70th power (most of them are hydrogen atoms with the smallest mass), and the 270th power of 2 is already greater than the 80th power of 10, which means that it doesn’t take 80 years at all. In less than a year, the total mass of these cancer cells has far surpassed our universe

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