Source: Prostate Cancer Cells, Wellcome Library

Let's review some safeguards the cell has to make to ensure sure damaged and/or abnormal cells don't complete the cell cycle and reproduce:

1. During G1 phase, the cell checks to make sure the chromosomes have been replicated properly.


2. A certain type of cyclin makes sure all chromosomes are attached to a spindle fiber before entering anaphase.


3. Cells have a characteristic called 'contact inhibition'. They will grow and divide until they begin to touch other cells. Then the cells slow down their division, and eventually stop reproducing.


4. Cells have chemical signals that tell them when to divide faster and cells that are nearby send signals for other cells to slow down or stop dividing. These signals ensure that cells don't 'overgrow' their boundaries and get in the way of other tissues. On the other hand, if you were to cut your finger, the cells around the wound would receive signals to divide quicker so that the cut could heal faster.


5. If a cell is damaged or has chromosomal problems, it receives a signal to 'self-destruct'!

Directions: Watch the following video to learn more about how cell growth is different in cancer cells.

Check for Understanding
Directions: Answer the following questions. (Some questions are from the reading and some are from the video.)

1. During what phase of cell division do the cells check to make sure the chromosomes have been replicated properly? Interactive popup. Assistance may be required.

   Check Your Answer

   G1

2. A certain type of cyclin makes sure all chromosomes are attached to a spindle fiber before entering what stage of cell division? Interactive popup. Assistance may be required.

   Check Your Answer

   anaphase

3. Normal cells will not divide when they receive stop signals from their ____________ cells but cancer cells ignore this signal. Interactive popup. Assistance may be required.

   Check Your Answer

   neighbor

4. When cancer cells continue to divide without stopping this can lead to the formation of a mass of cells that may form a ______________. Interactive popup. Assistance may be required.

   Check Your Answer

   tumor

5. Cancer cells are also different from normal cells in that they have the ability to divide ________________. Interactive popup. Assistance may be required.

   Check Your Answer

   indefinitely