Posted by Cancer Cell Growth
In this essay I will cover the course objective “describe the stages of mitosis”, additionally, I will expand on this topic by covering how these cells become cancerous and grow unhealthily in our bodies. According to the Center for Disease Control (CDC) in the year 2020 1.6 million new cases of cancer were reported, and 600,000 Americans died of cancer, (CDC, June 2023) and according to the American cancer society, roughly 40% of people will develop cancer at some point in their lifetime (American Cancer Society, January 2023). With such a high likelihood of facing this disease, its important to understand what it is, what causes it, and what it does to our bodies.
First, we’ll recap healthy cell replication within the human body, and what a normal cell’s life cycle looks like. A cells life cycle has four stages, for the sake of this project we will begin by talking about mitosis. Mitosis itself has many stages, beginning with prophase, then metaphase, then anaphase, telophase, and finally cytokinesis, where the cell is finally divided. After the stages of mitosis theres a gap phase (G1) where the organelles of a cell are duplicated to prepare to split. After the gap phase is the synthesis phase, where Chromosomes are duplicated in preparation to split the cell. Next is the second gap phase, where the cell continues to grow in preparation of mitosis. This second gap phase (G2) is followed immediately by mitosis again and the cycle continues. This whole cycle is called proliferation, and can take anywhere from 10 hours in rapidly proliferating cells, to weeks, months, or even entire lifetimes when it comes to the neurons in our brains. (Cooper et al., 2023)
Cancerous cell growth is described by the National Cancer Institute to be “a disease in which some of the body’s cells grow uncontrollably and spread to other parts of the body.” (National cancer institute, 2021) But before we can talk about the uncontrolled growth, lets talk about how growth is normally regulated. Regulated growth involves many “checkpoints” in the proliferation process that keep cells under control. The first of the three main checkpoints is the G1/S checkpoint or “restriction” checkpoint. This checkpoint looks at Cell size and nutrition to determine if a cell will continue to grow. The next checkpoint is the G2/M checkpoint, where a cell’s DNA is looked at for proper replication and any damages. Lastly is the Metaphase/Anaphase checkpoint, this checkpoint of course is during mitosis and is influenced by whether or not the spindle fibers in a cell bind to sister chromatids in a cell. (Rehman, et al., 2023) cells that do not pass these checkpoints go through apoptosis, or programmed cell death. Apoptosis is for any cells that are no longer needed, or pose a threat to the organism as a whole. (Alberts, et al., 2002)
Now that we know how cell multiplication happens and how it is regulated, lets talk about cancer, and how this cell growth goes awry. Cancer cells can become present in the body from three sources, errors in cell division, damage to DNA from harmful substances called carcinogens, (cancer causeing substances) such as tobacco. It is also possible to inherit cancer hereditarily from your parents. Typically these cancer cells are killed by the body, but if these cells live and go on to multiply, they can damage our body and even be fatal. Typically if a cancerous cell has lived longer than it is supposed to, or has multiplied beyond its means, it is because they don’t follow signals given from the body. Cancer cells will ignore signals to begin apoptosis and multiply without being told to do so. As they grow significantly and build up large clump of cells, called tumors. Blood vessels can even grow towards these tumors to supply them with oxygen and nutrients. Tumors may also break apart and travel to different areas of the body in a process called metastasis (National Cancer Institute, 2021)
The diagnosis for cancer is a rating scale, in stages 0 through 4, with Stage zero being the least developed cancer and stage 4 being the most. Stage 0 cancer is cancer “in situ” meaning that it is still in the location it originated, and has not spread, this cancer is still small and typically innefectual. Stage 1 and 2 cancer is the same, these are small cancers in situ, the only difference between these stages is that each stage is larger than the last. Stage 3 cancer has spread to surrounding tissues and lymph nodes, and stage 4 cancer is metastatic, having moved to distant parts of the body. (United Kingdom National Health Service, 2021)
| Fig 1. |
To put all this into perspective using something we can all picture in our heads, as a simple demonstration of cancer cells in the body compared to healthy cells, I used a pepperoni pizza. A typical, well made pizza, which I used to represent the body, has healthy cells (represented with pepperoni toppings) spread evenly, over it, multiplying healthily. If this body contained cancerous cells, they would multiply unregulated and create a tumor. To demonstrate this on a pizza, I covered half of the pizza in a normal amount of pepperoni, and the rest of the pizza in a mound of pepperoni to represent a tumor. Figure 1 shows the pizza as it came out of the oven, the left side clearly containing more toppings than the right, this represents the cancerous growth of a tumor. Figure 2 shows the pizza after I removed all the toppings to demonstrate how it cooked differently, as I observed voth visually and through a taste test, the side containing more pepperoni had almost a puddle of grease, which made the pizza less appetizing, unhealthier, and made the dough weak and soggy. While cancer in the body hardly makes us any “greasier” than before, one thing that I didnt anticipate that actually captures this analogy well, was the cheese. After removing the toppings to see the damage, a lot of cheese got peeled up from the pepperoni “tumor” an apt analogy for the way cancer uses up the bodies resources, multiplying and causing harm until the body dies.
| Fig. 2 |
In conclusion, Cancer is a complicated disease that causes significant harm to the body, and can be life changing or even fatal at its worst. Cancer begins when issues occur in cell proliferation and the life cycle of cells causing them to multiply beyond the bodies means. The body has many checkpoints and processes to prevent this but unfortunately these methods aren’t perfect, all of us still have the potential to develop cancer at some point in our lifetimes, whether its from what we eat and drink, if our parents had something, or we just get unlucky.
References
O’Connor, C. (2008). Mitosis and Cell Division. Nature news. https://www.nature.com/scitable/topicpage/mitosis-and-cell-division-205/
Rehman I, Gulani A, Farooq M, et al. Genetics, Mitosis. [Updated 2023 Mar 27]. In: StatPearls . Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK482449/
Alberts B, Johnson A, Lewis J, et al. Molecular Biology of the Cell. 4th edition. New York: Garland Science; 2002. Programmed Cell Death (Apoptosis) Available from: https://www.ncbi.nlm.nih.gov/books/NBK26873/
Britannica, T. Editors of Encyclopaedia (2023, November 7). mitosis. Encyclopedia Britannica. https://www.britannica.com/science/mitosis
NHS. (2021, December 16). What do cancer stages and grades mean?. NHS choices. https://www.nhs.uk/common-health-questions/operations-tests-and-procedures/what-do-cancer-stages-and-grades-mean/
InformedHealth.org. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. How do cancer cells grow and spread? 2013 Nov 6 [Updated 2019 Jun 19]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279410/
American Cancer Society. Lifetime Probability of Developing and Dying from Cancer, 2017-2019 (Cancer Facts & Figures 2023 Supplemental Data). 2023. Accessed at https://www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/annual-cancer-facts-and-figures/2023/sd4-lifetime-probability-2023-cff.pdf on January 12, 2023.
What is cancer?. National Cancer Institute. (2021, October 11). https://www.cancer.gov/about-cancer/understanding/what-is-cancer Centers for Disease Control and Prevention. (2023, June 8). Cancer Data and statistics. Centers for Disease Control and Prevention. https://www.cdc.gov/cancer/dcpc/data/index.htm
Lucas’s objective for this project was to cover how cells become cancerous and grow unhealthily in human bodies. He first chose to talk about cell replication within the human body and compare that to what a normal cell’s life cycle looks like. They managed to tie in mitosis which was the objective of Lucas’s project and how the steps of mitosis and the gap phase where the organelles of a cell are duplicated to prepare to split. He also talked about uncontrolled growth and how it’s normally regulated. Lucas explains how cell growth can go away and how they become present. Cancer cells become present in a human’s body from three different sources which are errors in cell division, damage to DNA from harmful substances for example tobacco. Finally the last source is hereditary from your parents and extended family.
For Lucas’s abstract part of the steam project he made two different pepperoni pizzas. He used the crust base as a healthy body and he used pepperoni toppings that had healthy cells all across the pizza. If there was a tumor in the pizza the pepperonis would multiply and create a tumor. In figure one he made the right side of the pizza more even and spread out while the other side was clumped up to represent a tumor. In figure two he shows the results after baking the pizza. The side with the tumor(pile of pepperonis) had a lot more grease than the other side. When pulling up the pepperonis the cheese also came up with it and that was to represent how much damage a tumor can really affect the human body.