Cancer: The closest humanity has gotten to immortality

March 15, 2022 by anon


Immortality is quite an absurd notion. All living things are innately mortal. All living things are doomed to meet their maker.  What living entity would dare to resist such a fundamental law?

Cancer cells.

They resist apoptosis, also known as programmed cell death. They resist autophagy, the self-eating mechanism that facilitates the breakdown of (not specifically) oncogenic molecules within the cell. Cancer cells are masters of survival, innovative in many ways to bypass their fate. The desperation to survive, being malfunctioning cells is emotionally depicted in the manga (and its animated adaptation), Cells At Work! by Akane Shimizu. It personifies the Cancer Cell as an outcast who is unable to conform to the society he was born into and takes it into his own hands to have the society conform to him, thus turning him into the villain of the series.

Apoptosis in very simple terms is a self-disassembly with safety precautions in place so as to not disturb the cells around. There are many ways cancer cells avoid apoptosis with regards to the many ways apoptosis can be triggered. The responses to these triggers are controlled by the balance (or rather an imbalance) between pro-apoptotic and anti-apoptotic members of the Bcl-2 family of proteins. The balance tipping to pro- would create a cascade of protein degradation within the cell. Cancer cells tip the balance the other way by increasing the levels of anti- and maintaining it. These anti-apoptotic Bcl-2 proteins bind themselves to the proteins Bax and Bak, which when uninhibited release pro-apoptotic signals, thus silencing the threat. [1]

Another trigger of apoptosis is the activation of a tumour-suppressing protein called TP53. TP53 responds to DNA damage. It is like a sensor that is connected to an emergency self-destruct mechanism. In cancers, there is a loss of tumour-suppressive function in TP53. The sensor is disconnected. It cannot detect any unwanted changes to the DNA. [1]

Quite ironically in cancer, the expression of myc protein which is an apoptotic trigger only makes the cells proliferate faster. [2]

Cancer cells that are too stressed know how to lay low and bide their time until the coast is clear. By stress, the implication is a drug-based therapy. While autophagy starves and shrinks the cell, it may not completely destroy it. The cancer cell simply goes into a dormant mode, fooling the mechanisms. Once the cause of the stress is gone, it reverses it dormancy. This is the major reason why cancers tend to come back more aggressive than before. [1]

Necrosis (induced cell death) indeed may be the most reliable way to truly kill cancer cells, but the bursting open of the cell contradictorily exposes other cells to oncogenic factors. This is a villain that fits the popular trope, ‘If I’m going down, I’m taking you with me.’

While the resistance of the first cancer cell is all it takes, immortality lies in the division of that cell into several genetically identical ones non-stop. In research, these are called cell lines. The oldest and most common cell line is HeLa. It is named after Henrietta Lacks, the cervical cancer patient from whom it was taken in 1951 before she died. As her cells are immortalised, so is her legacy in the book The Immortal Life of Henrietta Lacks by Rebecca Skloot.

I would like to conclude by remembering a character from the animated series Fullmetal Alchemist: Brotherhood– Ling Yao, the prince who went to a different land in search of an elixir of immortality only to find that it came at an unimaginable cost. Is cancer the path to understanding immortality?

References:


Guest post written by Haimanthi K Raghavan

Haimanthi has a master’s degree in Human Disease Genetics from the Centre for Human Genetics, Bengaluru. She is a science enthusiast, illustrator, creative writer and loves exploring beyond her domain. She also is an avid reader and her favourite genres are popular science, science fiction, philosophy and classical literature. Co-founder of a Pop-Culture club (Graphic.Inc) during her undergraduate days, she likes to integrate references from anime/manga/comics in her science writing to make it more relatable to the current youth.

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