What goes wrong with a normal cell when it becomes cancerous?

Several fundamental changes occur in a normal cell when it transforms into a cancerous cell. These alterations disrupt the cell's regular growth, division, and interaction with its surroundings, leading to uncontrolled growth and other characteristics associated with cancer. Here are some key changes that occur:

1. Dysregulated Cell Division:

- Normally, cells undergo a highly regulated process of cell division to maintain tissue growth and repair. Cancer cells lose this regulation, dividing rapidly and uncontrollably. This results in an accumulation of excessive cells, forming a tumor or malignant growth.

2. DNA Damage and Mutations:

- Genetic mutations accumulate in cancer cells, disrupting the正常genes involved in cell division, growth, and other essential functions. These mutations can arise from various factors, including environmental toxins, oxidative stress, radiation, or errors during DNA replication. Some mutations occur in genes that play crucial roles in regulating cell growth and preventing cancer development, known as oncogenes and tumor suppressor genes.

3. Sustained Angiogenesis:

- Angiogenesis, the formation of new blood vessels, is a normal process essential for tissue growth and repair. Cancer cells hijack this process, promoting the development of new blood vessels that supply the tumor with nutrients and oxygen, enabling its continuous growth.

4. Loss of Apoptosis (Programmed Cell Death):

- Apoptosis is a programmed, self-destruction mechanism for eliminating damaged or unnecessary cells. Cancer cells evade apoptosis, allowing them to survive longer and accumulate in the body.

5. Invasion and Metastasis:

- Cancer cells develop the ability to invade surrounding tissues, breaking through the normal barriers that confine healthy cells to their designated areas. Moreover, some cancer cells become able to spread to distant sites through the process of metastasis, forming secondary tumors.

6. Reprogrammed Metabolism:

- Cancer cells alter their metabolism to meet their energy and growth demands. They rewire their metabolic pathways, often exhibiting a preference for generating energy through glycolysis, even in the presence of sufficient oxygen (known as the "Warburg effect").

7. Immune System Evasion:

- Cancer cells can evade detection and destruction by the immune system through various mechanisms. They may express molecules that make them appear similar to normal cells or suppress the activity of immune cells that would normally target and eliminate them.

8. Reprogrammed Cellular Identity:

- In some cases, cancer cells may undergo changes in their cellular identity, known as epithelial-mesenchymal transition (EMT). This enables them to lose their typical epithelial characteristics and gain the ability to migrate and invade like mesenchymal cells.

These changes disrupt the normal cellular processes, ultimately leading to the uncontrolled growth, invasion, and spread of cancerous cells, ultimately contributing to the complex and multifaceted nature of cancer.