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This is the completed version of my essay, in which I chose to explore the topic of how HeLa cells were a breakthrough in the field of chromosome research. Not only did scientists determine the proper number of chromosomes a human has, but they also developed techniques to visualize and discover them. I also delved into the story of HeLa cells, giving Henrietta Lacks credit where credit was due, as well as discussing the injustices many face due to racism. However, this is merely the first draft, and it lacks many crucial elements.

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Breakthrough in Chromosome Research Permanently Changes Medicine

(ai generated, canva)

Allison Estudillo

ENGL 21003: Writing for the Sciences

Professor Debra Williams

February 26, 2024

If a single person could help save millions of lives with just their cells, the probability of them wanting to help those lives would be extremely high. However, the question is, what if they never had a choice? What if they were never permitted to give their cells to help those lives and were never even made aware that they were the reason why so many people have lived? There has been a woman who has saved millions of lives with just her cells. However, she was unfortunately never alive to be made aware of that fact. Her name was Henrietta Lacks. The discovery of her cells has made a breakthrough in chromosome research that has permanently changed medicine. Henrietta Lacks cells, also known as HeLa Cells, had helped advance the techniques that scientists used to count the number of chromosomes the human cell actually had. There are techniques such as fluorescence in situ hybridization (FISH), spectral karyotyping (SKY), and there’s also comparative genomic hybridization (CGH). These techniques allow scientists to visualize human chromosomes—all thanks to the help of Henrietta Lacks cells. By discovering how many chromosomes the human cell actually has, scientists were now able to diagnose disorders regarding the chromosomes. HeLa cells continue to study the human chromosome, seeing the structure and genetic mutations. Henrietta Lacks’s cells have improved the science field in many ways that one might even realize.

You may wonder how Henrietta Lacks’s cells could have drastically changed science. Unlike regular human cells, our cells eventually die after a limited number of repetitions. Henrietta Lacks’s cells are quite peculiar because they do the opposite; her cells can replicate rapidly and are considered immortal because they never die. HeLa cells became the most fundamental necessity in science as her cells were in multiple medical achievements. Her cells play massive roles in gene mapping, cancer treatments, and chromosome research development. The discovery of how many chromosomes a human cell actually has was quite outstanding as it uncovered why there were so many disorders regarding chromosomes. Initially, scientists had stated that there were indeed 48 chromosomes in each cell. However, with the discovery of Henrietta Lacks’s cells and the advancements of new techniques to visualize the chromosomes, scientists discovered that there are actually 42 chromosomes. Now, chromosomes are important because they are our structures that carry our genetic information. Chromosomes determine an individual’s physical traits, such as the color of a person’s eye, the texture or color of their hair, and so much more. Not only do our chromosomes carry that information, but they also carry the information about diseases we may be susceptible to. Chromosome abnormalities are quite common when our genetic information is altered, each person has a set of two chromosomes, while people who were born as males have X and Y chromosomes. While people who were born as females only contain X chromosomes (Masaru Ueno, 2023). 

Any change in our chromosomes can cause significant damage to who we may be as a person; any biological alteration can have consequences such as genetic disorders, cancer, and abnormalities that develop over time. Genetic disorders that alternate chromosomes can be classified into three major types, Monogenic, Autosomal Recessive, and X-linked disorders. The first type of genetic disorder would be Monogenic disorders; the cause of monogenic disorders would be from mutations in a single gene; some examples of this type of disorder would be cystic fibrosis, sickle cell Armenia, Duchenne muscular dystrophy (Andrew B. Lori, 1994). There are three ways monogenic disorders are inherited. The first is that if one parent has this mutated gene, their child would have a 50% chance their child might inherit it as well; this would be called autosomal dominant genetic disorder. The second way one may inherit a genetic disorder is an autosomal recessive genetic disorder, in which a person must inherit two copies of a mutated gene, one coming from each parent. The person would develop the disorder when having both genetic mutated genes from each parent. The third type would be X-linked, where the mutation is always found in the X chromosome. This type of inheritance primarily affects the male gender; males with XY chromosomes will inherit the mutated gene and have the genetic disorder. Females have two X chromosomes; they inherit the genetically mutated gene, and the other X chromosome might compensate instead; however, they would still be carriers for this gene mutation. The second primary type of genetic disorder is called multifactorial disorder, which is caused by mutations surrounding multiple genes combined with environmental factors. The genetic disorders a person may get from multifactorial disorders are coronary heart disease, hypertension, and diabetes (Andrew B. Lori, 1994). Unlike monogenic disorders, which follow three main patterns in inheritance, multifactorial disorders are more complicated because they combine mutated genes and environmental factors. The third primary type of genetic disorder is structural chromosomal changes, which occur when the chromosome is altered in structure, meaning parts of it may be missing, duplicated, misplaced, or rearranged. These changes in the structure can cause consequences relating to growth, development, and overall human function. Some genetic disorders in this category are Down, Turner, and Klinefelter  (Andrew B. Lori, 1994). However, without the discovery of Henrietta Lacks’s cells, we would have never known about these disorders and the number of chromosomes humans have. However, the main subject is the techniques derived from Henrietta, which have helped the science field evolve when such genetic abnormalities are detected.  

In order for scientists to find and study chromosomes, they must use special techniques. There are methods such as fluorescence in situ hybridization (FISH) and spectral karyotyping (SKY), and there is also comparative genomic hybridization (CGH); these methods help researchers detect any chromosomal abnormalities. The techniques allow science better to understand diseases such as cancer and genetic disorders.  The first beneficial technique would be Spectral karyotyping, also known as SKY. Spectral karyotyping is a technique in which scientists see chromosomes in different colors. This technique also incorporates another technique, fluorescence in situ hybridization (FISH), where each chromosome uses different colors to label the chromosomes. However, it is used for studying cancer cells in the sky because it helps scientists understand how chromosomes become so unstable (Merryn Macville, 1999). The following image is an example of Spectral Karyotyping in use.

Figure 1 from Popescu et al. (2006) illustrates the 24-color SKY hybridization of a HeLa metaphase from subclone A.

This image uses spectral karyotyping and G-Banding to analyze the abnormalities found in HeLa cells. To identify how spectral karyotyping is used in these images, you must remember that SKY assigns different colors to chromosomes to visualize better, recognize them, and see any chromosome abnormality. At the same time, G-branding can be identified by remembering that it provides a black-and-white view of the chromosomes.  A proper technique brought up before would be fluorescence in situ hybridization (FISH). Fluorescence in situ hybridization is a technique that has been used to look for specific DNA sequences on chromosomes. It is incorporated in gene maps and helps locate genetic disorders and viruses such as HPV18 in cells such as cancer cells, which is found in cervical cancer (Merryn Macville, 1999).

Figure 2. Cytogenetic analyses of sequence-integrated clones. (2001). In Integration of cytogenetic landmarks into the draft sequence of the human genome. Nature, 409, 954. ©  Nature Publishing Group.

This image lets you see fluorescence in situ hybridization (FISH in action. It is used here to find and highlight certain parts of DNA on the chromosomes. This helps researchers understand what may be wrong in a patient’s DNA and could explain what congenital disabilities or conditions they genuinely have. The third valuable technique for the science field is Comparative Genomic Hybridization (CGH). Comparative Genomic Hybridization is a technique to help find the missing or extra parts of a patient chromosome. This technique is crucial for cancer research because chromosome changes can induce tumors to grow (Merryn Macville, 1999). This technique is sometimes paired with fluorescence in situ hybridization (FISH) to help get a clearer picture of how cancer can affect DNA.

Figure 1 from Bennett et al. (2006) illustrates the microarray and FISH analyses of case 3.

In the picture, scientists use comparative genomic hybridization (CGH) to check if a patient is missing or has extra DNA in their chromosome. The grad labeled A shows any changes in the color red, red being that something is missing. In contrast, there is extra DNA in green; for the images labeled B and C, fluorescence in situ hybridization (FISH) is used to see what part of the DNA is missing. All in all, this helps scientists better understand the genetic disorders patients may have. With all the techniques developed with the help of Henrietta Lacks cell, people can now truly understand what may be wrong with them genetically. Before scientists came across HeLa cells, they had never truly understood the human cell and were never truly sure about the amount of chromosomes we had. Without knowing the number of chromosomes we have, it was helpful to understand why some patients generally had disorders. However, with the discovery of HeLa cells, new techniques were developed to visualize chromosomes, identify genetic disorders and cancer, and better understand cancer. This could help anybody figure out what is truly wrong with them and help them save countless hours trying to figure out what genetic disorder they may have or how they have it to begin with.

In each breakthrough in the science field, there will always be a discussion in mind about the issues that can arise surrounding the topic at hand. In the science field especially, there has been a troubling and complex history regarding ethnic groups and the medical field altogether. The scientific advancements that have troubling history behind the achievements, primarily this breakthrough in chromosome research. The discrimination and unethical medical practices that ethnic groups have undergone to get these advancements have struck fear in these groups. This fear in these groups has built a foundation of mistrust, as these ethnic groups continue not to trust the medical field at all. Henrietta Lacks is the main person in this discovery who has helped society overcome COVID-19 and many other problems. In this breakthrough, she continues to do the same. However, the discovery of her cells is unjust. In the year 1951, her cancer cells were taken from her without her consent and knowledge. With the use of her cells, countless medical achievements came after. After she had unfortunately passed away, her family had not been made aware of the power she honestly had until decades later.(NIH, Lacks family reach understanding to share genomic data of HeLa cells, 2013). Even today, there seem to be concerns about

how companies or insurance companies could access a person’s genetic data without their knowledge.
In conclusion, the scientific achievements of HeLa cells have helped society in more ways than one. Scientists being able to properly discover how or why genetic disorders work has solved many problems and opened up doors to more research on other topics regarding the chromosomes that could one day lead to an everlasting solution. However, these achievements are still troubling to this day. How HeLa cells were gathered and used affected this ethnic group once more without properly asking for permission for the cells in her body. The fact that it took literally almost a decade for her family to know that Henrietta Lacks’s cells were being used this entire time without their knowledge. That a piece of Henrietta Lacks was still alive, and her family had no notice.

References

U.S. Department of Health and Human Services. (2015, September 15). NIH, lacks family reach 

understanding to share genomic data of Hela cells. National Institutes of Health. https://www.nih.gov/news-events/news-releases/nih-lacks-family-reach-understanding-share-genomic-data-hela-cells

Andrews, L. B. (n.d.). Assessing genetic risks: Implications for health and social policy. 

Implications for Health and Social Policy | The National Academies Press. https://nap.nationalacademies.org/catalog/2057/assessing-genetic-risks-implications-for-health-and-social-policy 

Macville, M., Schröck, E., Padilla-Nash, H., Catherine Keck, B., Ghadimi, M., Zimonjic, D., 

Popescu, N., Ried, T. (1999). Comprehensive and Definitive Molecular Cytogenetic Characterization of HeLa Cells by Spectral Karyotyping. Cancer Res, 59 (1): 141–150.
https://aacrjournals.org/cancerres/article/59/1/141/505037/Comprehensive-and-Definitive-Molecular-Cytogenetic 

Ueno, M., (2023). Exploring Genetic Interactions with Telomere Protection Gene pot1 in Fission
Yeast. Biomolecules, 13(2).
http://dx.doi.org.ccny-proxy1.libr.ccny.cuny.edu/10.3390/biom13020370 Citation: O’Connor, C. (2008) Fluorescence in situ hybridization (FISH). Nature Education
1(1):171.
https://www.nature.com/scitable/topicpage/fluorescence-in-situ-hybridization-fish-327/#