Devita, Hellman, and Rosenberg's Cancer

LWBK1006-02 LWW-Govindan-Review November 24, 2011 11:18

28 DeVita, Hellman, and Rosenberg’s CANCER: Principles and Practice of Oncology Review

Answer 2.18. The answer is A.

Autophagy is regulated by mTOR in the PI3-kinase/AKT pathway that

functions to link nutrient availability to cellular metabolism. Defective

autophagy has been implicated in carcinogenesis in certain human breast,

ovarian, and prostate tumors. Type I programmed cell death, apoptosis,

is regulated by Bax/Bak and BH3-only proteins. APC/C is the anaphase

promoting complex/cyclosome that regulates sister chromatid separation

in mitosis.

Answer 2.19. The answer is C.

Autophagy is involved in recycling normal cellular constituents, damaged

protein/organelle removal, innate immunity by removal of cells infected

by intracellular pathogens, acquired immunity by promoting T-cell sur-

vival/proliferation, and protection against aging. Cell lysis secondary to

surrounding inflammation or insult is a feature of necrosis.

Answer 2.20. The answer is B.

Lysosome activation is a feature of apoptosis, as is cell shrinkage, bleb-

bing of the plasma membrane, chromatin condensation, and intranu-

cleosomal DNA fragmentation without being followed by surrounding

inflammation. Necrosis is characterized by rapid swelling of the cell, loss

of plasma membrane integrity, and release of intracellular components

into the extracellular compartment resulting in an acute inflammatory

response.

Answer 2.21. The answer is B.

The Warburg effect describes an observation where most cancer cells pro-

duce energy by anerobic glycolycis even when oxygen is plentiful. This is

an inefficient way of producing energy. Generating less ATPs per mode of

glucose metabolized explaining the high glucose requirement by tumors.

Answer 2.22. The answer is B.

For tumor cells to support their vast metabolic demands, they must induce

and sustain a supply of new blood vessels through the process of angio-

genesis. This is the basis of antiangiogenic therapy as a means of cancer

treatment.

Answer 2.23. The answer is B.

Bevacizumab is the first successful antiangiogenic agent that has shown

activity in randomized phase III trials. It is a monoclonal antibody to

VEGF. It has been shown to be effective in combination with chemother-

apy for the treatment of metastatic colorectal cancer, breast cancer, renal

cell carcinoma, and nonsmall cell lung cancer.

Answer 2.24. The answer is A.

Tumor angiogenesis is first mediated by several proteolytic enzymes,

such as matrix metalloproteinases, and urokinase plasminogen activator,