Chapter 40 Cancer
Tumor Suppressor Genes: Guard against cancer formation
Proto-oncogenes: Control normal cell growth and proliferation
- When mutated they become oncogenes
o Oncogenes – unrestrained cell division
Cancer cells are nonuniform in architecture, disorganized, and misshapen
- Undifferentiated = anaplastic
Cell Cycle: sequence of growth stages that a cell moves through for mitosis and
regeneration
4 Phases of mitosis:
1. Prophase – condenses chromosomes; spindles appear
2. Metaphase – chromosomes reorganize as 2 separate sets of 23 chromosome
pairs
3. Anaphase – sets are pulled to opposite poles by spindle fibers
4. Telophase – 2 distinct nuclear envelopes; spindles dissolve
Immunocompetence decreases aging → older adults are more susceptible to tumor
development
NO restrictive checkpoints or rest stages with cancer cells
Sporadic genetic mutations: acquired during a lifetime due to carcinogen exposure
TP53 – tumor suppressor gene; controls apoptosis
Guardian of the genome
Cancers activated by viruses:
- Cervical cancer is activated by HPV
Carcinogens: complex multistep process
Tumor Suppressor Genes: Guard against cancer formation
Proto-oncogenes: Control normal cell growth and proliferation
- When mutated they become oncogenes
o Oncogenes – unrestrained cell division
Cancer cells are nonuniform in architecture, disorganized, and misshapen
- Undifferentiated = anaplastic
Cell Cycle: sequence of growth stages that a cell moves through for mitosis and
regeneration
4 Phases of mitosis:
1. Prophase – condenses chromosomes; spindles appear
2. Metaphase – chromosomes reorganize as 2 separate sets of 23 chromosome
pairs
3. Anaphase – sets are pulled to opposite poles by spindle fibers
4. Telophase – 2 distinct nuclear envelopes; spindles dissolve
Immunocompetence decreases aging → older adults are more susceptible to tumor
development
NO restrictive checkpoints or rest stages with cancer cells
Sporadic genetic mutations: acquired during a lifetime due to carcinogen exposure
TP53 – tumor suppressor gene; controls apoptosis
Guardian of the genome
Cancers activated by viruses:
- Cervical cancer is activated by HPV
Carcinogens: complex multistep process
