Question

Imagine that you are a medical student working in a cancer research laboratory. Your boss has given you samples of cancer cells and blood from a patient. She has told you that the cells have no mutations in any of their signaling molecule proteins (i.e., all the proteins are normal), but the cells' signaling transduction properties are not normal, causing them to be cancerous. Which of the following could account for the increased cell proliferation in the patient?

A) The cells taken from the patient have more growth factor receptors than normal.
B) Both choices are correct.
C) The concentration of a signaling molecule in the patient is higher in the patient than usual.

Answer 1

The enhanced cell proliferation leading to cancer in this case could be due to having more growth factor receptors or a higher concentration of a signaling molecule, which overstimulate cell division, even without mutations in the signaling proteins. The correct option is B.

Step-by-step explanation:

The question pertains to the cellular mechanisms leading to cancer despite the absence of mutations in signaling molecule proteins. Since all the signaling proteins are normal, the enhanced cell proliferation in the patient's cancer cells can be due to two non-mutational changes:

• The presence of more growth factor receptors on the cell surfaces than normal (Choice A), which could lead to heightened sensitivity and over-response to growth signals.
• An increased concentration of a signaling molecule within the patient (Choice C), which could result in the overstimulation of normal signaling pathways, promoting excessive cell division.

Therefore, both scenarios could account for the malfunctional signaling transduction properties in the absence of protein mutations, leading to cancer. Thus, both choices are correct. Therefore, the correct option is B.