INTEGBI 169 Chapter Notes - Chapter 11: Neoplasm, Essive Case, Ovarian Cancer
5 Jun 2018
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○ Lung cancer in non-smokers is relatively common in some Chinese populations
and has been linked to an activating mutation of the epidermal growth factor
receptor.
○ The threshold of smoke exposure that induces cancer in this population is much
lower than the general population.
○ The development of lung cancer in the population with this mutation typically
requires exposure to some smoke from burning wood or coal as a trigger for
cancer development.
○ Genes affecting DNA repair:
○ Cancer may involve genes affecting DNA repair.
■ For example, p53 is a cellular protein that plays a major role as an
intracellular signal to initiate DNA repair or to stop proliferation when
stressed.
■ Familial inheritance of p53 mutations leads to a high rate of sarcoma,
breast cancer and other cancers.
■ p53 mutations are rare.
○ Gene mutation:
■ BRCA1 is a human gene that belongs to a class of genes known as tumor
suppressors.
■ Mutations of the BRCA1 gene is linked with hereditary breast cancer.
■ BRCA1 mutations are quite common and increase the risk for breast
cancer, however, they persist despite being harmful probably because
the breast cancer typically develops after reproductive years.
■ Ashkenazi Jews generally have one of two mutations not found in other
populations, suggesting a founder effect.
● Cultural Evolution
○ The more children a woman has and the longer she breast feeds, the lower her
risk for breast cancer will be.
○ Celibate women have higher rates of breast cancer.
○ Modern women have on average many more menstrual cycles and higher
cumulative estrogen exposure than hunter-gatherer females who have (and had)
lower body fat and more interruption of their cycles with pregnancy and
lactation.
○ Additionally, human lactation leads to loss and renewal of ductal epithelial cells,
thus removing cells with somatic mutations.
Document Summary
Lung cancer in non-smokers is relatively common in some chinese populations and has been linked to an activating mutation of the epidermal growth factor receptor. The threshold of smoke exposure that induces cancer in this population is much lower than the general population. The development of lung cancer in the population with this mutation typically requires exposure to some smoke from burning wood or coal as a trigger for cancer development. Cancer may involve genes affecting dna repair. For example, p53 is a cellular protein that plays a major role as an intracellular signal to initiate dna repair or to stop proliferation when stressed. Familial inheritance of p53 mutations leads to a high rate of sarcoma, breast cancer and other cancers. Brca1 is a human gene that belongs to a class of genes known as tumor suppressors. Mutations of the brca1 gene is linked with hereditary breast cancer.
