11.7 unregulated cell division can lead to cancer Flashcards
Cancer Cells: Characteristics
Cancer cells lose control over cell division, form tumors, and can migrate to other body parts.
Benign Tumors
grow slowly, resemble parent tissue, and remain localized, but may require removal if they obstruct organ function.
Malignant Tumors
do not resemble parent tissue, have irregular structures, and can spread. Identification is crucial for diagnosis.
Metastasis
Cancer cells invade surrounding tissues, travel via bloodstream or lymph system, and form secondary tumors in distant sites.
Normal Cell Cycle: Regulation
The cell cycle is regulated by positive (growth factors) and negative (inhibitors) regulators, ensuring cells divide only when needed.
Oncogene Proteins
Oncogenes, mutated positive regulators, stimulate cell division. Tumor suppressors, inactive in cancer cells, inhibit division. Example: p53.
Tumor Suppressor: P53
P53, a transcription factor, regulates cell cycle checkpoints. Mutations in the p53 gene are found in over 50% of human tumors.
Tumors: Complexity
Tumors often have multiple genetic abnormalities, involving several oncogenes and tumor suppressors.
Tumor Treatments: Surgical Removal
Surgical removal is optimal, but not always possible. Treatment often targets the cell cycle.
Tumor Treatments: Targeting Cell Division
Drugs that prevent cell division or promote apoptosis are used to target tumors.
Henrietta Lacks: HeLa Cells
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: Genetic Imbalance
HeLa cells have a genetic imbalance that heavily favors cell reproduction, contributing to their continuous growth in laboratory cultures.
