Question

Question 3: . I In some breast cancers, the cancerous cells express the receptor for progesterone. Progesterone's structure is shown below. When progesterone is present, the progesterone receptor acts like a transcription factor and enhances the transcription of many genes, including c-myc. c-myc makes a protein that promotes cell division. Imagine that in some of these cancers the progesterone receptor has mutated so that it does not o require progesterone to bind to DNA. A. Is the progesterone receptor located on the cell membrane or in the cytoplasm, and why? Explain in two sentences or less. B. Is the type of cell division that c-myc stimulates most likely mitosis or meiosis, and why? Explain in two sentences or less. C. How will the mutant progesterone receptor affect the amount of c-myc transcribed, and why? Explain in two sentences or less.

Answer 1

1. Progesterone receptor is present in the cytoplasm of the cell. It can act as a transcription factor upon bound by the progesterone molecule. It is a steroid receptor and steroids are easily permeable through plasma membrane.
2. c-myc induces mitosis. Mitosis is the cell division happens in normal cells. Meiosis happens in the gametes.
3. In the mutant progesterone receptor the receptor ligands binding cassette is constitutively active without the progesterone. This receptor will constitutively transcribe c-myc which lead to over expression of c-myc and thus uncontrolled cell death will happen and cancer will progress faster.