11.7 unregulated cell division can lead to cancer

Cancer cells lose control over cell division, form tumors, and can migrate to other body parts.

grow slowly, resemble parent tissue, and remain localized, but may require removal if they obstruct organ function.

do not resemble parent tissue, have irregular structures, and can spread. Identification is crucial for diagnosis.

Cancer cells invade surrounding tissues, travel via bloodstream or lymph system, and form secondary tumors in distant sites.

The cell cycle is regulated by positive (growth factors) and negative (inhibitors) regulators, ensuring cells divide only when needed.

Oncogenes, mutated positive regulators, stimulate cell division. Tumor suppressors, inactive in cancer cells, inhibit division. Example: p53.

P53, a transcription factor, regulates cell cycle checkpoints. Mutations in the p53 gene are found in over 50% of human tumors.

Tumors often have multiple genetic abnormalities, involving several oncogenes and tumor suppressors.

Surgical removal is optimal, but not always possible. Treatment often targets the cell cycle.

Drugs that prevent cell division or promote apoptosis are used to target tumors.

Cells from Henrietta Lacks, known as HeLa cells, are widely used in research. They have a genetic imbalance favoring cell reproduction over death.

HeLa cells have a genetic imbalance that heavily favors cell reproduction, contributing to their continuous growth in laboratory cultures.