Lecture 17 - Cancer

Question 1

What does benign mean?

Answer 1

Tumor is not capable of indefinite growth.

Question 2

What does malignant mean?

Answer 2

Invasive tumor that can grow indefinitely.

Question 3

Define metastasis.

Answer 3

Cancerous cells dislodge from tumor which are carried to other tissues where they proceed to proliferate.

Question 4

Define carcinoma.

Answer 4

Tumor from endodermal or ectodermal tissue.

Question 5

Define leukemia/lymphoma.

Answer 5

Malignant tumors of the hematopoietic cells of the bone marrow.

Question 6

Define sarcoma.

Answer 6

A tumor of the mesodermal connective.

Question 7

Can proto-oncogenes become oncogenes? How?

Answer 7

Yes; By undergoing mutation

Question 8

What do proto-oncogenes do?

Answer 8

Code for proteins which control growth of different things, including cells.

Question 9

What are oncogenes?

Answer 9

The viral counterparts of cellular proto-oncogenes.

Question 10

Cyclins and CDKS which are proto-oncogenes drives/promote what?

Answer 10

Drive/promote cell division under unfavorable conditions and become oncogenes.

Question 11

When an abnormal cell escape, what does this mean?

Answer 11

The checks (G1 checks, synthesis, M stage) have failed. And we will have cancer thanks to the oncogenes.

Question 12

List the 3 major mechanisms of the conversion of proto-oncogenes to oncogenes.

Answer 12

Carcinogens, viruses, and radiation

Question 13

What causes malignant transformation?

Answer 13

The translocation of a proto-oncogene from one chromosomal site to another, or a separate chromosome.

Question 14

List 2 diseases that is the result of malignant transformation.

Answer 14

Chronic myelogenous leukemia, and Burkitt’s lymphoma.

Question 15

What happens if p53 is mutated in metastatic colon cancer?

Answer 15

It cannot stop the process of the tumor forming in the carcinoma.

Question 16

What are tumor specific transplanted antigens (TSTAs)? How is it induced?

Answer 16

Antigens that are unique to tumor cells.
Chemically, physically or virally induced.

Question 17

What are tumor associated transplanted antigens (TATAs)? How is it induced?

Answer 17

Antigens that are not unique to tumor cells.
Expression of an embryonic gene, and overexpression of a normal cellular protein.

Question 18

List factors of tumor evasion of the immune system.

Answer 18

Antitumor antibodies, antibodies modulate tumor antigens, low levels of Class I MHC molecules, and poor costimulatory signals

Question 19

What does antitumor antibodies do?

Answer 19

Act as a blocking factor forming complexes with tumor antigens.

Question 20

What effects does low levels of class I MHC molecules have?

Answer 20

Has a profound effect on the cell-mediated cytotoxic T cell response.

Question 21

What happens when there is poor costimulatory signals?

Answer 21

Lack of costimulatory molecules cannot stimulate CTL response.

Question 22

Cancer immunotherapy involves…

Answer 22

Manipulation of costimulatory signals, enhancement of APC activity, cytokine therapy, and monoclonal antibodies.

Question 23

What does monoclonal antibodies cause in cancer immunotherapy?

Answer 23

Can cause direct complement-mediated lysis, or can be conjugated with an agent which can be directly delivered to the tumor cell.

Question 24

What happens during the manipulation of costimulatory signals?

Answer 24

Transfect genes for costimulatory signals (B7 ligand) into tumor cells to activate CTLs.

Question 25

What happens during the enhancement of APC activity?

Answer 25

Transfect a gene for GM-CSF to increase macrophage activation.

Question 26

List 2 kinds of tumor antigens.

Answer 26

TSTAs and TATAs