George Washington's New Hatchet A: Do yuou know who was the first president (总统) of the United States? B: George Washington. A: Right. Do you know that he used to be a naughty (淘气的)boy? B: Oh, _______________ I am?
【多选题】Cancer cells are totally different from normal cells in that:
A.
1. Cancer cells have a reduced dependence on signals from other cells for their survival, growth, and division. 2. Cancer cells can survive levels of stress and internal derangement that would cause normal cells to kill themselves by apoptosis.
B.
3. Unlike most normal human cells, cancer cells can often proliferate indefinitely. 4. Most cancer cells are genetically unstable, with a greatly increased mutation rate and an abnormal number of chromosomes.
C.
5. Cancer cells are abnormally invasive, at least partly because they often lack certain cell adhesion molecules, such as cadherins, that help hold normal cells in their proper place. 6. Cancer cells are abnormally avid for nutrients, which they use to generate much of their ATP by glycolysis in the cell cytosol.
D.
7. Cancer cells can survive and proliferate in abnormal locations, whereas most normal cells die when misplaced. 8. As cancer cells evolve, they secrete signals that influence the behavior of cells in the surrounding connective tissue, thereby modifying the tumor’s microenvironment.