Infectious Causes of Cancer

Question 1

What is the MOA for transformation via Epstein Barr Virus?

Answer 1

Expression of latent genes EBNA2 & LMP1 that promote cell proliferation and telomerase activation

Question 2

What is a direct-acting oncogenic virus?

Answer 2

A virus that introduces a new transforming virus directly into the genome

Question 3

Kaposi’s sarcoma is associated with a CD4+ count…

Answer 3

Less than 400

Question 4

What onco-proteins are associated with HPV?

Answer 4

E6 & E7

Question 5

What virus is associated with Kaposi’s Sarcoma?

Answer 5

Human Herpesvirus 8

Question 6

E6 onco-protein interacts with what normal cellular protein?

Answer 6

p53

Question 7

How does a slow-transforming retrovirus differ from an acute-transforming retrovirus?

Answer 7

An acute-transforming retrovirus carries an oncogene. A slow-transforming retrovirus does not carry an oncogene, but inserts into the genome near a tumor suppressor or oncogene

Question 8

What HPV strains are high risk for genital and oral cancers?

Answer 8

HPV 16 & 18

Question 9

What is the function of the EBNA2 gene of EBV?

Answer 9

Transcriptional factor that promotes proliferation

Question 10

True/False. A retroviral oncogene is likely from a previous host.

Answer 10

True. The oncogene also plays no role in viral replication so the virus is likely to have replication issues.

Question 11

Gastric cancer and MALT lymphoma are associated with what pathogen?

Answer 11

H. pylori

Question 12

What is the normal function of Rb?

Answer 12

When hypophosphorylated, binds E2F and prevents initiation of the cell cycle

Question 13

E7 onco-protein interacts with what normal cellular protein?

Answer 13

Rb

Question 14

What is an indirect-acting oncogenic virus?

Answer 14

A virus that alters the expression of pre-existing genes

Question 15

What is a major pathogenic factor of H. pylori known as an effector of cancer?

Answer 15

cagA

Question 16

What factors play a role in the ability of H. pylori to cause cancer?

Answer 16

Flagella, urease, exotoxins, secretory enzymes, proteins, LPS

Question 17

Burkitt’s Lymphoma consistently has a translocation of what gene?

Answer 17

c-myc-proto-oncogene

Question 18

What cancer is associated with EBV?

Answer 18

Burkitt’s Lymphoma

Question 19

Kaposi’s sarcoma rarely causes cancer. What is the MOA for when it does?

Answer 19

LANA1 binds p53 to block its action. LANA1 also promotes tumor growth by immune suppression and angiogenesis

Question 20

Retroviruses in the (lytic/lysogenic) phase are generally associated with cancer formation?

Answer 20

Lysogenic - cell is rapidly dividing and not dying to release viral particles

Question 21

What is the MOA of E6 onco-protein?

Answer 21

Binds and inhibits p53 so DNA damage accumulates

Question 22

What is the normal function of p53?

Answer 22

Induces growth arrest at G1/S phase due to DNA damage

Question 23

What is the MOA of HTLV as a cancer-associated virus?

Answer 23

Inserts into the genome near transcription factor binding sites and promotes T cell proliferation

Question 24

Viral proteins that interact with normal cellular proteins are called…?

Answer 24

Onco-proteins

Question 25

True/False. Helminth infection prevents cancer development due to H. pylori infection.

Answer 25

True. Prevents creation of a chronic inflammatory environment

Question 26

True/False. All strains of HPV have onco-proteins E6 & E7.

Answer 26

True. But the proteins behave differently from different strains so not all cause cancer

Question 27

What cytokine is stimulated by H. pylori and plays a role in actin remodeling?

Answer 27

IL-8

Question 28

What is the function of the LMP1 gene of EBV?

Answer 28

TNF receptor that puts B cells in a proliferative state and activates telomerase