Cancer Development Mechanisms

21.03.2024

WHAT ARE THE CANCER DEVELOPMENT MECHANISMS?

Cancer development results from a number of complex mechanisms such as genetic and epigenetic changes, RNA variations and protein modifications. Mutations in DNA can lead to uncontrolled proliferation and growth of cancer cells. These genetic changes contribute to the development of cancer by affecting the cell's protein production. At the RNA level, changes that occur during the transcription of genes into mRNA can lead to abnormal protein production. Furthermore, by altering their signaling networks, cancer cells deviate from normal cell functions, leading to uncontrolled cell division or evasion of cell death. Epigenetic changes may also contribute to cancer development by altering gene expression.

Image 1: Cancer is the process of uncontrolled proliferation of normal cells under the influence of environmental factors and genetic mutations.

A series of complex mechanisms underlie cancer development. Understanding these mechanisms allows the development of new treatment and prevention strategies in cancer research.

• Genetic Changes: Mutations in DNA are one of the key features of cancer cells. These mutations can disrupt or alter normal protein functions, leading to uncontrolled proliferation and growth of cells. Genetic changes can be somatic (acquired during a person's lifetime) or hereditary (germline). Research has shown that different types of cancer and different tumor masses derived from the primary tumor in the same person contain different somatic mutations.

• RNA Variations: During the transfer of genes from DNA to mRNA (messenger ribonucleic acid), DNA sequences called introns are removed and exons are joined. This process creates an mRNA molecule that produces a functional protein. In cancer cells, this process can be altered to produce abnormal proteins, which can trigger uncontrolled cell proliferation and growth.

• Protein Changes: Cancer cells can alter their signaling networks through mutations, increased expression, or modifications of proteins, making them suitable for their development and progression. This causes cancer cells to stop responding to normal cues and avoid uncontrolled cell division or cell death.

• Epigenetic Changes: In addition to genetic mutations, epigenetic modifications, which are chemical changes in DNA and/or proteins linked to it, can also lead to the development of cancer. Epigenetic modifications regulate how and when genes are expressed, which may play an important role in cancer development.

Understanding these mechanisms helps develop new treatment and prevention strategies in cancer research. A detailed understanding of each mechanism allows us to better unravel the complex nature of cancer and develop effective interventions. Therefore, cancer-related research has focused on the molecular characterization of tumors and understanding how genetic mutations contribute to cancer.

Image 2: After cancer cells penetrate the surrounding tissues, they can enter the blood and spread to other organs.

CANCER DEVELOPMENT STEPS

The stages of cancer development include a series of steps from tumor formation to its spread:

• Initiation:This stage begins with a change in the cell's genetic material (mutation), preparing the cell to become cancerous. This genetic change can occur as a random event or be triggered by external factors, such as exposure to a carcinogenic substance.

• Trigger (Promotion): The triggering stage is associated with factors that allow a cell to become cancerous after going through the initiation stage. These may be triggers such as environmental substances or certain medications. Triggers do not cause cancer on their own, but they act on cells that have passed the initial stage.

• Hyperplasia: When a genetically modified cell divides uncontrollably, excessive cell accumulation occurs in the tissue. The cells maintain their normal appearance but are numerous.

• Dysplasia: Additional genetic changes in hyperplastic cells lead to increasingly abnormal growth. Cells and tissue no longer appear normal and may become disorganized.

• Carcinoma in situ: Additional changes make cells and tissues even more abnormal. The cells are now spread over a larger area and the tissue is covered with changed cells in the starting position. This type of cancer can often be completely cured with surgery because the abnormal cells are clustered in a single location.

• Cancer (Malignant Tumors): These tumors have the ability to invade (penetrate) surrounding tissues and/or metastasize to areas distant from the local tissue. Metastatic tumors are the most dangerous tumors and account for the majority of cancer deaths.

• Spread: Cancer can spread directly to surrounding tissues (invasion) or spread to distant tissues or organs through the lymphatic system or blood (metastasis). Carcinomas typically spread using the lymphatic system, while sarcomas spread through the blood.

Understanding these steps is important in understanding how cancer develops and how it can be treated.

Resources:

https://cancerprogressreport.aacr.org/progress/cpr22-contents/cpr22-understanding-how-cancer-develops/

https://cancerprogressreport.aacr.org/progress/cpr23-contents/cpr23-understanding-the-path-to-cancer-development/

https://cancerquest.org/cancer-biology/cancer-development

https://www.merckmanuals.com/home/cancer/overview-of-cancer/development-and-spread-of-cancer