20.5 - Gene Expression & Cancer Flashcards
The differences between benign and malignant tumours Differences between tumour cells and normal cells How mutations can cause uncontrolled cell growth The role of abnormal methylation in cancer How oestrogen may contribute to some breast cancers (17 cards)
What are tumours?
Masses of cells from unrestrained cell division
What are primary tumours?
The original abnormal growths that develop where a cancer first begins.
What are secondary tumours?
Tumors formed when primary tumours spread to other regions of the body via metastasis.
What are the differences between benign and malignant tumours?
Growth pace
What are key features of tumour cells?
Irregular shape
How do mutations cause uncontrolled cell growth?
Mutations in tumour suppressor genes and proto-oncogenes
What is the role of tumour suppressor genes?
Regulate cell division
What happens when tumour suppressor genes mutate?
Uncontrolled cell growth
What is the role of proto-oncogenes?
Stimulate cell division
What happens when proto-oncogenes mutate?
Excessive cell division
What is the role of methylation in cancer?
Abnormal methylation affects gene expression
What is hypermethylation?
Increased methylation
What is hypomethylation?
Decreased methylation
How does hypermethylation affect tumour suppressor genes?
Silences them
How does hypomethylation affect proto-oncogenes?
Activates them
How may oestrogen contribute to breast cancer?
Stimulates cell division
Why is there a higher risk in postmenopausal women?
Higher oestrogen in breast tissue fat cells
