Lecture 33

Question 1

What is responsible for control of the cell cycle?

Answer 1

Cyclin-dependent kinases (CDKs), cyclins

Question 2

What is responsible for controlling the G1-to-S transition of the cell cycle?

Answer 2

Retinoblastoma protein (RB)

Question 3

What is responsible for controlling the G2-to-M transition of the cell cycle?

Answer 3

Mitosis-promoting factor (MPF)

Question 4

What is the function of Ras?

Answer 4

Responsible for fast mitosis in early embryonic development; very commonly mutated in cancers

Question 5

What is t(14;18)(q32;q21)?

Answer 5

Hallmark of follicular lymphoma is the chromosomal translocations that lead to hyper-upregulation of BCL2 expression in tumor cells (makes BCL2 extremely active)

Question 6

Explain microRNAs and their involvement in cancer initiation and progression

Answer 6

In cancers, there is often a very high upregulation of microRNAs; the oncogenes activate some microRNAs that will target the mRNA to downregulate those genes that are tumor suppressors or that control the cell cycle

Question 7

Why don’t elephants get cancer?

Answer 7

Elephants have 20 copies of p53 in their genome, while other mammals (and humans) have only 1; p53 snaps to action when cells suffer DNA damage, churning out copies of its associated p53 protein and either repairing the damage or killing the cell