The level of organisation within the body is so vast that even after much advancements in medicine, scientists are a long way from figuring things out completely. Look at a bowler at a cricket match or a ballerina and try to think of the coordination that is going within their bodies in order to maintain precise actions from their torso to their little fingers. Now visualise the inside of the body. While all these things are going on outside, there are a thousand things happening inside the body at the same time. The heart keeps pumping blood, the kidneys filter blood, the stomach is busy digesting food, the brain is processing the inputs that are coming from all the sensory organs etc. Each of these organs comprises cells. Even while you are reading this, thousands of new cells are being generated in various parts of the body, while a thousand others die.
Now let’s look at one of those cells. It’s a direct descendant from the first ever cell that was formed when the genetic material from the mother’s cell got together with those of the father and replicated to produce a foetus. The cell’s begin, differentiate, function and replicate giving rise to more cells. Even their death is tightly regulated by those said genetic material.
Let’s go into a little more detail. Cell replication is a process where two cells result from division of one cell. All cell organelle, including the genetic material, is replicated. This is a very complicated as well as an interesting process, but that is a story for another time. Replication is made unpredictable by it’s high chance to produce ‘mistakes’, which will in turn give rise to many disease conditions.
Do you remember that I told you that all this started with that one cell? Then how come there are thousands of different cell groups in our body? Nerve cells, epithelial cells, blood cells, muscle cells, the list goes on. That’s due to a process called cell differentiation, where a cell, after dividing acquires special features specific for a certain group of cells. These features are so specific that when it goes beyond a certain level, they loose the ability to replicate. Nerve cells and blood cells are examples of cells that can’t give rise to similar cells.
Then comes the cell death. It’s hard to believe that each cell in our body is pre-programmed to self destruct at command, but scientists have found that this is the case. This process is called ‘apoptosis’ or programmed cell death. This ‘command’ can come from the inside of the cell itself, specially when the cell is old, or from the nearby structures; which is how the fingers and toes are separated from each other in an embryo. This dying off is done in a very methodical manner so that none of the toxic or potentially harmful substances are leaked out from the cell, to be engulfed by a large cell and recycled instead.
Any deviation from this normal mechanisms causes disease. But there have been instances where this deviation has contributed to the advancement of modern medicine too. HeLa cells is one such example. HeLa is a cell line obtained from a cancer in the neck of the womb of a lady named Henrietta Lacks in 1951. These cells were obtained without her permission and she eventually succumbed to the same cancer. Even though the origin of the cell line was tragic, it has contributed immensely to the development of medicine. The important of HeLa cells is that due to an abnormality in the said ‘normal mechanism’, these cells can be made to replicate indefinitely inside a laboratory. That means non-depleting supply of genetically similar cells for the scientists to work on. It was once estimated that if the HeLa cells which were replicated and distributed worldwide are piled together, it would sum up to 50 million metric tons. These cells have contributed to many advancements in the fields of virology, vaccination and in mapping the human genome. May be going against the rules can be a good thing, in certain Situations after all. What do you think?