Why do bacteria and cancer cells without brains get out of the tortuous maze?
The labyrinth experiments carried out by scientists on bacteria and cancer cells are of great value to biomedicine. It provides a new window of research for understanding the early stages of mammalian embryonic development and the metastasis of cancer cells.
Perhaps you have only heard of scientists training mice to walk mazes, but did you know that cells and bacteria also walk mazes?
The latest issue of "Science" published an interesting study: Scientists from the Cancer Institute and the University of Glasgow made a simulated version of the Hampton Court maze, placing bacteria and cancer cells in it to see if they can If you walked out of the maze, I didn't expect that both the lower creatures and the basic units of life completed this task.
Why do scientists choose these two life units for maze experiments?
How did they get out of the maze?
What does this research result mean for humans?
A reporter from Science and Technology Daily interviewed relevant experts and asked him to talk about the mystery.
Why choose them to walk the maze?
The two "players" are not idlers and both move
"Dictyostelium discoideum", the name "You don't know it, and it doesn't know you" is translated into Dictyostelium discoideum.
There are so many microorganisms. Why do scientists at the Cancer Institute and the University of Glasgow think that this kind of bacteria can walk a maze and give it this opportunity?
"Dictyostelium discoideum can form a'body', that is, to'pile' itself up and form a multicellular body." Zhu Baoli, a researcher at the Institute of Microbiology, Chinese Academy of Sciences, told the Science and Technology Daily reporter that after becoming a multicellular body, their single cells There is also the ability to collaborate.
Being able to clump together and do things in groups, Dictyostelium discoideum presents a problem to scientists: Is it multi-celled or single-celled?
Because of this typical characteristic, around 2000, the National Institutes of Health classified Dictyostelium discoideum as a model organism between single-cell and multi-cell.
Biologists use them for scientific research to reveal a certain life phenomenon with universal laws.
So many scientists have used it for research, and Zhu Baoli has also studied it.
"It can migrate for a long time and long distances, but it does not move very clearly and does not have that vitality." Zhu Baoli said that it has to rely on a surface to move.
If you make a flat medium, you can visually observe that they are "displaced".
The colonies formed by common bacteria are fixed.
What really makes it a "star" is the genome research project.
Zhu Baoli introduced that 50 species of organisms were included in the genome project at that time. Dictyostelium discoideum was considered to be very meaningful for studying the evolution of organisms because it was between single-cell and multi-cell.
Studying how organisms evolve to humans is a goal of genome research, and Dictyostelium discoideum is listed as the starting point of evolution.
Compared with the lesser known of Dictyostelium discoideum, the "supernatural appearance" of cancer cells is obvious to all. It can be latent and metastasize.
"New England" magazine once reported a clinical case: a kidney transplant recipient grew a melanoma in the transplanted kidney. After excluding various factors, it was discovered after continuous investigation that the donor had received it 20 years ago. Melanoma, but later healed.
This case comparable to a criminal investigation drama fully shows that cancer cells are latent and can metastasize.
In the paper, the researchers also described the peculiarities of the two life units: the former can be found far away from its counterparts, and the latter can quickly spread cancer throughout the body.
How do they get out of the maze?
The concentration gradient of nutrients is the best "mark"
Since transfer is their daily routine, how do they get out of the maze?
Just as plants always chase sunlight, these two life units always chase nutrients.
How does the driving force of nutrition transform into the driving force of bacteria and cells?
The explanation is given in the paper that the self-generating gradient forms the driving force for the "long-distance migration" of bacteria and cells, and becomes the driving force for route decisions.
The so-called spontaneous gradient is the degradation of local nutrients by cells, creating a difference in nutrient concentration for themselves.
Take cancer cells as an example. They are recognized as the most nutrient-needed cells. Once they are produced, they will compete with the body for energy, which shows that they have a strong ability to decompose nutrients in the culture medium.
If the nutrients here are "eaten", the nutrient concentration in other places will be higher than the nutrient concentration here, and then a concentration gradient will be formed to promote the advancement of cancer cells.
So how do they judge which way to choose or where is a dead end?
It may be instructive to study how to move the maze.
According to records, there are three rules for the maze: After entering the maze, you can choose a road to go forward; if you encounter a dead end that is not accessible, you will immediately return and make a mark at the intersection; if you encounter a crossroad , Observe if there are any passages you have walked through. If you have one, choose one to go forward, and if you don’t, go back to the last intersection and make a mark.
Then repeat the steps described in Articles 2 and 3 until you find the exit.
Obviously, according to this rule, walking a maze requires no thinking, only a mark.
The concentration gradient of nutrients is the best "sign" for bacteria and cancer cells.
"A dead end means that nutrients will be exhausted and other cells will not come again. If the fork in the road eventually leads to a dead end, it will also cause the cells to go back and forth, and ultimately consume more nutrients than a smooth road." Zhu Baoli explained.
In terms of innovation, the entire research has invented methods that can observe and calculate the entire process, use the calculation of spontaneous gradients and mathematical models to predict the pathfinding ability of the cells in the maze, and use the actual cells in the maze to test the results.
What's the point of getting out of the maze?
Provides a new window for understanding cancer cell metastasis and other issues
In the process of development and metastasis, cell migration is usually guided by chemotaxis, that is, cells will migrate from low concentration to high concentration area according to the concentration gradient of certain chemical substances.
However, people often pay attention to the chemotaxis in the environment. In fact, in many cases, environmental gradients cannot guide cells to migrate far away across the complex environment.
This study confirms that the self-generating gradient can navigate long and tortuous paths for bacteria and cells, and make accurate choices between a live road and a dead end, which enables cells to effectively solve complex maze problems.
The researchers also used a mathematical method to make a precise description, and found the relationship between the accuracy of the cell to find a way out and the diffusion rate of the attractant, cell speed, and path complexity, and can predict its success rate.
This result has very important value for biomedicine. For example, it provides a new window for understanding the early stages of mammalian embryonic development and the metastasis of cancer cells.
Perhaps you are still amazed by the ability of bacteria and cancer cells to walk the maze.
But from an evolutionary perspective, whether microbes or cancer cells, they have been living on the earth for a long time, young humans may now just wander at the door of the "maze" created by these ancient creatures.
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Found evidence that "cancer cells are very similar to primitive cells"
For a long time, cancer cells have always been the thorny opponents of human beings, and they are also the subject of most medical research.
Some past studies have given some evidence that "cancer cells are very similar to primitive cells".
For example, after viruses, harmful bacteria, and harmful chemicals invade, they "sneak into" the life activities of the cells to attack the cells, while the original cells will use dormancy to deal with the hazards. When these hazards have naturally decayed, they will start life activities.
This characteristic of "trying the guts and waiting for opportunities to fight again" has also been found in some cancer cells.
It is worth mentioning that this study has found more conclusive evidence for "cancer cells are very similar to primitive cells."
The study confirmed that cancer cells and primitive cells can move long distances, and the principle of movement is the same.
In addition, Yu Jun's team, a professor at the Chinese University of Hong Kong School of Medicine, recently discovered bacteria in gastric cancer tissue and observed an increase in bad bacteria.
"Foreign scientists have also recently discovered bacteria in cancer tissues, but it is not clear how the bacteria came, whether it is the cancer caused by the bacteria or after the immune system has a loophole, they took advantage of it." Zhu Baoli said, it may be other s reason.