Cancer Tutorial

Problem 4: Smoking and p53

The sputum (fluid coughed up from the lungs) of many smokers contain cells with mutations in the genes for p53. The smoking-induced mutations appear to be an early signal showing that cancer of the lungs will follow. What is the likely relationship between early p53 mutation and the development of lung cancer?

	p53 with a mutation directly stimulates the growth of cancer cells.
	p53 causes a cell to enter G0, blocking cell division.
	Mutant p53 triggers the M phase of the cell cycle leading to abnormal cell division.
	Mutations in p53 would prevent abnormal cells from dying by apoptosis.