How do cancer cells overcome the natural checkpoints in the cell cycle?

Cancer cells often bypass the natural checkpoints of the cell cycle, which normally regulate cell division and ensure that cells only proliferate when appropriate. One significant way they achieve this is by synthesizing their own growth factors.

In normal cells, growth factors are external signals that promote cell division and regulate the cell cycle. However, cancer cells can become autonomous in their growth signaling. By producing their own growth factors or exhibiting sensitive receptors that continually signal the cell to divide, cancer cells effectively ignore the regulatory mechanisms that would normally halt their proliferation in the absence of sufficient external stimuli. This independence from external growth signals allows them to grow and divide uncontrollably, leading to tumor development.

The other choices, while related to aspects of cell behavior, do not directly address how cancer cells overcome cell cycle checkpoints. For example, consuming more nutrients may provide the energy needed for division but does not specifically pertain to the evasion of cell cycle controls. Doubling their chromosomes can occur in cancer cells, but this is often a result of uncontrolled division rather than a strategy for evading checkpoints. Remaining dormant until conditions are favorable is characteristic of some normal cells or specific types of cancer cells in certain stages, but it does not explain how they generally evade the regulatory processes governing the