Immortality: A Divine Characteristic Or A Biomolecular Tool
Abstract
Immortality has been historically perceived as a divine characteristic in various religions, including Islam. Philosophically and scientifically, humans have sought to decode the mystery of this phenomenon and have been fascinated by the possibility of living as immortal beings. Yet, with limitations in the tools needed to find a concrete answer for this mystery, it was difficult to rely on a specific answer. As science significantly progressed, and the tools became available especially in the 1950s, scientists’ newest obsession became culturing cells that were immortal in vitro. The experiments accompanying that discovery revealed that the mystery of immortality could be embedded in our cells, specifically in an enzyme called telomerase that functions after each DNA replication preceding cell division. This paper illustrates the long journey from the Qur’an to the first cell line.
Immortality: A Divine Characteristic or a Biomolecular Tool?
Immortality is defined as the ability to live forever. For so long, people perceived this characteristic as one of God’s or a divine figure’s they believed in. Poets, storytellers, and scientists were equally captivated by immortality that they dedicated their literary and scientific journeys to primarily address the possibility of possessing that ability through chemicals, such as the elixir of life. Centuries later, specifically in the 1950s, scientist and physicians began to seek other alternatives to obtain immortality: creating cell lines. Having cells grow outside the organism’s body, in vitro, was a dream that was achieved by cells mainly known as HeLa, the first line that grew and was tested on in vivo. HeLa cells revolutionized modern medicine and enabled us to test the processes, including DNA replication, occurring regularly within cells and unrevealed the nature of biomolecular tool that became associated with immortality.
Immortality: An Intersection of Science and Religion
From religion to science, the mystery of immortality seems more reachable now than ever. With advanced tools revealing what is within the cells, immortality became related to an enzyme known as telomerase. However, the journey leading to it took various chemicals, myths, and laboratories.
Islam and Immortality
“Everyone upon the earth will perish, and there will remain the Face of your Lord, Owner of Majesty and Honor.” (Qur’an 55:26) This verse was interpreted as proof that immortality was only a characteristic of Allah, the name of God in Arabic and used by Muslims. It shows that the all living creatures, whether demons, angels, human beings, and every creature shall decease, and the ability to live eternally distinguishes Allah, the Creator, and His creations. Similar to other religions, Islam has created this distinction early on and described immortality as unattainable. However, it seemed that the obsession of humans by this characteristic will continue to ignite questions that challenge their core beliefs, and recent discoveries show that we are closer than ever to finding answers to those questions that kept humans dreaming of this ability between elixirs of life and fiction.
Henrietta Lacks
In 1951, Henrietta Lacks laid in a bathtub in her small family home (Skloot., 2010). She has noticed that she had been bleeding recently, even though the date did not coincide with her usual menstruation days. Reluctantly, she slipped her finger within her vagina and sensed a lump that she did not recall coming across before.
Henrietta was the epitome of working tirelessly while never frowning. As the lump grew, she started losing bits of her joyful nature, and stress took over her life. As a Black, poor woman in Maryland, the options for treatments were rather limited. In fact, the only option was Johns Hopkins Hospital, which was the only hospital that treated Black patients at that time.
While preparing for diagnosis, Henrietta sensed death approaching her – immortality, in her case, was not an option, nor a rational wish. Little did she know that the body she was looking at helplessly would revolutionize modern medicine and guide the journey of achieving immortality.
Cell Cultures and HeLa Cells
Unlike their ancestral scientists, physicians in the 1950s did not give the dream of immortality any attention – it was unrealistic, and believing it was an indicator of stupidity. Their new dream was achieving not humans’ immortality, but the immortality of their cells in vitro.
Initially, it seemed impossible. Imitating the nature of the human body outside of it, similar temperature, nutrients, etc., was not reasonable. However, physician George Gey persisted. He continued to collect samples from the patients at the Johns Hopkins Hospital even though they all died within a few days of their excision. One day, however, this streak of failing experiments stopped once Henrietta arrived for her diagnosis.
Physician Howard Jones excised a biopsy and ran a series of tests that, wrongly, showed Henrietta was diagnosed with epidermoid carcinoma. Although she left with the wrong diagnosis, her cells were given to Gey, who discovered that his dream became a reality on that day – Henrietta Lacks’ cells grew in vivo and gave us the first cell line known as HeLa that paved the way for the greatest discoveries in medicine, ranging from gene mapping to eradicating polio. Yet, the question was regarding the ability of HeLa cells to continue to grow weeks and months after their excision, compared to other cells that only survived for a few days in Gey’s laboratory, which did not allow further experimentation and examination to be performed on them. The answer was embedded in our cells, specifically in our DNA.
Cell Division and DNA Replication
Deoxyribonucleic acid (DNA) is molecule that resides in the nuclei of cells (Freeman et al., 2017). This molecule carries out hereditary information that is passed through generations. Simply, DNA carries the recipe that is read and translated to make us the diverse individuals we are – different heights, eye colors, hair textures, and skin tones. DNA is a polymer, a molecule that is composed of smaller units called monomers. The building blocks, monomers, are nucleotides, which are made of a phosphate group, a deoxyribose (sugar), and one of four nitrogenous bases (adenine, guanine, thymine, and cytosine.)
To carry out that information to other generations, to grow, or to simply repair tissue damage, our cells divide into identical daughter cells, with each one ideally possessing an identical DNA sequence. In order for cells to achieve division successfully, they undergo a process known as DNA replication, which ensures each daughter cell has its own copy of DNA.
Since DNA is a double-helix molecule, enzymes known as helicase separate the two strands with the help of single-stranded binding proteins from reannealing to each other. Once the strands are separated, an enzyme called primase attaches a few ribonucleic acid (RNA) bases that allows another enzyme called DNA polymerase III to begin building the daughter strand.
Once DNA polymerase III finishes adding the complementary bases (adenine to thymine, cytosine to guanine), the beginning primers made by primase need to be removed as they are RNA bases, not DNA’s. Hence, another DNA polymerase known as DNA polymerase I removes the RNA bases and replaces them with DNA bases. On one of strands that had its primers happening to be at the end of the strand, the space left empty cannot be synthesized as synthesis of DNA bases requires primers, and removing a primer to add another one is not even a solution. Cells, at this point, cannot pass this strand with the missing bases to one of its daughter cells. If the cell must leave out that space empty, it must cut that part. After multiple cell divisions, this causes the DNA to become shorter and shorter, resulting in insufficient amount of information needed to repeat cell division and causing the cell’s death. How can cells solve this issue? How can they continue DNA replication without shortening the DNA itself and ensuring the cells die due to their inability to further divide?
Telomerase
Telomerases are RNA-dependent, DNA-synthesizing enzymes. This means they use a template made of RNA bases to synthesize DNA bases. Cells use telomerase to solve the issue removing the primer presented earlier (Green, J. 2018).
After the removal of primers, telomerase extends the parental strand with DNA bases. Then, it begins synthesizing new complementary bases to fill the spaces caused by the removal of the primer in addition of the newly extended space. Now that problem is solved, telomerase ensures that DNA does not undergo any shortening, resulting in more cell divisions, which, in turn, causes the cells to grow older instead of dying earlier (ASU. 2018).
The amount of available telomerase depends on the cell type and its need. Telomerase is the reason behind the ability of HeLa cells to grow continuously. Cancer, which is the rapid, uncontrolled growth of cells is ignited by telomerase that extends the DNA of cancerous cells and enables them to undergo multiple cell divisions.
Once scientists connected the dots, telomerase became a possible answer to our questions regarding immortality (ASU. 2018) Now, in fact, we are searching for ways to regulate its production and activity to both solve the life-long mystery of immortality and solve leading causes of death, such as cancer.
Cell Growth, Cancer, and Death
Excess production of telomerase is equivalent to rapid growth. In other words, this is cancer. Scientists are currently working on researching how the production rates of telomerase contributes to cancer progression, and how controlling this has the potential of cancer prevention and alleviation.
Not only does discovering the cause of extending the life cycle of cell helpful in cancer, but it also raises the possibility of extending the average expectancy of life of human beings. A new bioengineering tools are being discovered and tested, we will have the opportunity to introduce telomerase to cells that may not produce them naturally. We could use them to heal faster by introducing it in excess amounts of damaged tissue areas.
As the HeLa cells continue to grow during this moment in labs across the world because of the telomerase high production of them, we may, one day, have the ability to express the genes responsible of telomerase production in our cells in a regulated manner that makes us immortal.
References
- Freeman, S., Quillin, K., Allison, L. A., Black, M., Podgorski, G., & Taylor, E. (2017). Biological science. New York, NY: Pearson.
- Skloot, R. (2010). Immortal life of Henrietta Lacks. New York, NY: Crown Publishing Group.
- Green, J. (2018, February 23) ASU Scientists Unveil a hidden secret of the immortality enzyme telomerase. Retrieved from https://asunow.asu.edu/20180223-discoveries-asu-scientists-unveil-immortality-enzyme-telomerase
- BBC News. (2018, February 11). Can ageing be delayed, stopped or even reversed? Retrieved from https://www.youtube.com/watch?v=p_4UPdFqgIQ
- Arizona State University. (2018, February 27). Hidden secret of immortality enzyme telomerase: Can we stay young forever, or even recapture lost youth? Retrieved from https://www.sciencedaily.com/releases/2018/02/180227142114.htm
- The Conversation. (2019, April 25). End of ageing and cancer? Scientists unveil structure of the ‘immortality’ enzyme telomerase. Retrieved from http://theconversation.com/end-of-ageing-and-cancer-scientists-unveil-structure-of-the-immortality-enzyme-telomerase-95591
