How do normal cells protect themselves from accumulating mutations in genes that could lead to cancer? How do cancer cells differ from normal cells in these processes?

Verified step by step guidance

1. Normal cells have several mechanisms to protect themselves from accumulating mutations. One key mechanism is the DNA repair system, which identifies and corrects errors that occur during DNA replication or due to environmental damage.
2. Another protective mechanism is the cell cycle checkpoints. These checkpoints ensure that cells do not proceed to the next phase of the cell cycle until any DNA damage is repaired, preventing the propagation of mutations.
3. Apoptosis, or programmed cell death, is a process that eliminates cells with irreparable DNA damage, thus preventing them from becoming cancerous.
4. Cancer cells often have mutations in genes that regulate these protective mechanisms. For example, mutations in tumor suppressor genes like p53 can lead to a loss of cell cycle control and failure to undergo apoptosis.
5. Additionally, cancer cells may have increased genomic instability, which leads to further mutations and the ability to evade normal cellular controls, promoting uncontrolled growth and division.

Key Concepts

DNA Repair Mechanisms

Normal cells possess sophisticated DNA repair mechanisms that detect and correct mutations in their genetic material. These include processes like nucleotide excision repair and mismatch repair, which help maintain genomic integrity. By repairing DNA damage, cells can prevent the accumulation of mutations that may lead to cancer.

Cell Cycle Regulation

Cell cycle regulation is crucial for ensuring that cells only divide when they are ready and that any damaged DNA is repaired before replication. Proteins such as cyclins and cyclin-dependent kinases (CDKs) control the progression through the cell cycle, while checkpoints can halt the cycle to allow for repair, preventing the propagation of mutations.

Apoptosis

Apoptosis, or programmed cell death, is a mechanism that normal cells use to eliminate damaged or potentially cancerous cells. When cells detect irreparable DNA damage, they can trigger apoptosis to prevent the spread of mutations. In contrast, cancer cells often evade apoptosis, allowing them to survive and proliferate despite having significant genetic damage.