Introduction
Cancer is a disease that causes uncontrolled growth and spread of abnormal cells in the body. It is a complex condition caused by several factors, such as genetic abnormalities, environmental exposures, and lifestyle decisions. The accumulation of genetic mutations in cell DNA is one of the most common causes of cancer. DNA, or deoxyribonucleic acid, is the genetic substance that supplies the blueprint for all living species’ development and function. It comprises four fundamental building elements called nucleotides placed in a particular order to form each individual’s unique genetic code. When DNA is damaged or altered, it can disrupt cell function and contribute to cancer development.
When a mutation arises in a cell’s DNA, the process of cancer initiation begins. According to “The Genetics of Cancer,” This mutation can be induced by several sources, including radiation, chemicals, viruses, and faults during DNA replication or repair. A mutation might disrupt the cell’s usual function, leading it to divide and grow uncontrolled. As the altered cell divides and grows, it can create a mass of cells known as a tumor.
Tumors are classified as benign when they are not cancerous and do not spread to other areas of the body or malignant when they infect neighboring tissues and organs and spread to other body parts via the bloodstream or lymphatic system. In this paper, we will look at how cancer begins in the DNA, leading to a mutation and eventually to a tumor, as well as how cancer is related to DNA and cell division.
Biology and History of How Cancer Starts in DNA
The biology and history of how cancer begins in the DNA may be traced back to the 1940s when DNA was discovered as a genetic material and the subsequent understanding of how mutations in DNA can lead to cancer. Oswald Avery and his colleagues established 1944 that DNA is the genetic substance that transmits information from generation to generation (Pezzella et al., 34). This finding cleared the path for James Watson and Francis Crick to identify the DNA structure in 1953, which gave the foundation for understanding how DNA acts as the blueprint for life.
Scientists began to pinpoint the genetic changes that occur in cancer cells in the 1960s. A mutation in the KRAS gene that regulates cell growth and division was one of the first genetic mutations discovered (Pezzella et al., 46). KRAS mutations have been found in a range of malignancies, including lung, colon, and pancreatic cancer. Since then, technological advancements have enabled the detection of countless more genetic abnormalities that lead to cancer formation. Mutations in the TP53 gene, which regulates cell growth and division, are detected in more than 50% of all human malignancies.
How Cancer Is Related to DNA and Cell Division
Changes, or mutations, in the DNA of cells that regulate cell division cause abnormal cell growth. DNA mutations can occur spontaneously or due to environmental factors such as chemical or radiation exposure. A complex system of checks and balances regulates cell division in normal cells (Cancer Learning Center). This system ensures that cells only divide when necessary and in a controlled manner. A mutation in a cell’s DNA, on the other hand, can disrupt this system and cause the cell to divide uncontrollably. These abnormal cells can divide indefinitely and form tumors, invading and damaging nearby tissues and organs.
Mutations in genes that usually suppress tumor growth or regulate cell death can also cause cancer. According to “The Genetics of Cancer”, when these genes are mutated, they cannot perform their normal functions, allowing abnormal cells to proliferate. Cancer cells can also develop the ability to evade the body’s immune system and resist cell death. This can happen due to additional gene mutations that control these processes.
Four Coordinated Processes of the Cell Division Cycle
Cell Growth
During the cell expansion process, the cell will produce additional organelles and cellular components necessary for cell division. This will cause the cell to expand in size. This process involves the replication of ribosomes, mitochondria, and other organelles and the production of new proteins and lipids (Carlberg and Eunike 68). The cell also expands in volume and surface area as it gets ready to copy its genetic material and divide into two daughter cells. This process takes place when the cell prepares to divide.
DNA Replication
DNA replication is duplicating the DNA in the nucleus before cell division. This procedure is critical for transmitting genetic information from generation to generation. The DNA molecule comprises two complementary strands, each serving as a template for producing a new complementary strand during replication. Enzymes unwind the DNA molecule, and each strand serves as a template for DNA polymerase enzymes to synthesize a new complementary strand (Carlberg and Eunike 70). As a result, each chromosome has two identical copies, each with one of the original strands and one newly synthesized strand. This ensures that each daughter cell obtains a complete set of chromosomes.
Distribution of the Duplicated Chromosomes to Daughter Cells
One of the most critical processes during cell division is passing duplicated chromosomes onto the daughter cells. The spindle apparatus, a structure of microtubules that attach to the chromosomes and pull them apart, is responsible for separating the duplicated chromosomes and pulling them apart during this process phase (Carlberg and Eunike 73).
The spindle apparatus comprises two centrosomes that move to opposite poles of the cell and combine to form spindle fibers, which then attach to the centromeres of the chromosomes. The length of the spindle fibers is then reduced, which results in the duplicated chromosomes being pulled apart and toward the opposite poles of the cell. Due to this, it is guaranteed that each daughter cell will receive an entire and identical set of chromosomes upon division. Following the successful segregation of the chromosomes, the cell can move on to the final stage of the cell division process, known as cytokinesis. During this stage, the cell physically divides into two daughter cells.
Cell Division
The process by which a single cell divides into two or more daughter cells is known as cell division. Following cell growth, DNA replication, and the distribution of duplicated chromosomes to daughter cells, this is the final stage of the cell cycle. Cell division is classified into two types: mitosis and meiosis. The replicated chromosomes are separated into two identical sets during mitosis, dividing the cell into two daughter cells.
This process is required for tissue growth and repair in the body. The number of chromosomes is halved during meiosis, resulting in four genetically diverse daughter cells. This process is required for sexual reproduction as well as the generation of genetic diversity. Cell division, in general, is a tightly controlled and coordinated process that ensures the faithful transmission of genetic information from one generation to the next.
These four processes are tightly controlled and coordinated to ensure that the daughter cells have the correct number of chromosomes and are genetically identical to the parent cell. The cell cycle is also governed by a series of checkpoints that ensure the cell is ready to move on to the next stage and that any DNA damage is repaired before the cell divides. If these checkpoints fail, it can result in abnormal cell growth and, potentially, cancer development.
Conclusion
Cancer is a disease caused by uncontrolled cell growth and division in the body. Cell division is tightly regulated by several proteins and signaling pathways in the body, and genetic mutations in DNA significantly contribute to cancer development. On the other hand, mutations in genes that control cell division can disrupt these signals and cause cells to divide uncontrollably, forming a tumor. Understanding the relationship between DNA and cell division in cancer development is critical to developing new and effective treatments.
Works cited
“Cancer Learning Center.” Huntsman Cancer Institute | University of Utah Health. 2023. Web.
“The Genetics of Cancer.” National Cancer Institute. 2022. Web.
Pezzella, Francesco, et al. Oxford Textbook of Cancer Biology. Oxford UP, 2019.
Carlberg, Carsten, and Eunike Velleuer. Cancer Biology: How Science Works. Springer Nature, 2021.