When cells lose control in cancer?

Cells lose control in cancer due to a complex series of genetic alterations that disrupt normal cellular processes, including cell division, growth, and death. These alterations can occur in various genes that regulate these processes, leading to the development and progression of cancerous cells.

Key genetic changes that contribute to the loss of control in cancer include:

1. Oncogene Activation: Mutations in proto-oncogenes can convert them into oncogenes, which are genes that promote uncontrolled cell growth and proliferation. These mutations can lead to the overactivation of oncogenic proteins that drive cancer development.

2. Tumor Suppressor Gene Inactivation: Tumor suppressor genes play a critical role in preventing uncontrolled cell growth and promoting cell death when necessary. Mutations or deletions in tumor suppressor genes can disrupt their normal function, allowing cells to escape normal growth regulatory mechanisms.

3. DNA Repair Defects: Cells have DNA repair mechanisms to fix errors in the genetic material. Defects in these mechanisms can lead to the accumulation of mutations, contributing to genomic instability and the emergence of cancer cells.

4. Telomere Dysfunction: Telomeres are protective caps at the ends of chromosomes that shorten with each cell division. When telomeres become critically short, cells can enter a state of senescence (growth arrest) or undergo apoptosis (programmed cell death). Mutations in telomere maintenance genes can lead to telomere dysfunction, allowing cells to bypass these checkpoints and continue dividing uncontrollably.

5. Epigenetic Alterations: Epigenetic changes involve modifications to the DNA or its associated proteins without altering the underlying DNA sequence. Abnormal epigenetic modifications can affect gene expression patterns, leading to the activation of oncogenes and silencing of tumor suppressor genes, contributing to cancer development.

These genetic alterations can result in dysregulated cell cycle progression, evading apoptosis (programmed cell death), sustaining angiogenesis (formation of new blood vessels), activating invasion and metastasis, enabling replicative immortality, and reprogramming energy metabolism.

Collectively, these genetic alterations disrupt the normal cellular control mechanisms, allowing cells to escape normal regulatory processes and acquire the hallmarks of cancer.