Question

P-glycoprotein 1 (Pgp) is a membrane protein that normally protects the cell by using energy from ATP to pump a wide range of toxins and other foreign compounds out of the cell, so that they can be removed by the body. This includes a large range of drugs, including crizotinib and ceritinib. Some cancer cells have developed a resistance to many drugs (known as multidrug resistance) based on genetic changes to Pgp. Which of the following mechanisms would be likely to promote multidrug resistance? (Select two answers.)

changes to regulation or signaling that decrease expression of Pgp

changes to regulation or signaling that increase expression of Pgp

an amplification of the region of the genome encoding Pgp

a deletion of the region of the genome encoding Pgp

Answer 1

P-glycoprotein 1 or Pgp is a membrane protein that works by pumping out toxins and drugs in an ATP-dependent manner.

Cancer cells are targeted by a large number of drugs but these are not effective many times on cancer tissues. This is due to the expulsion of these drugs by the cancer cells. The protein responsible for expulsion is Pgp. Hence to ensure that the expulsion is active, the cancer cells should be allowing higher expression levels of Pgp.

The increased levels of Pgp will facilitate a large amount of drug removal.

Hence the correct option is b (changes to regulation or signaling that increase expression of Pgp).