Tumor suppressor genes

Question 1

RB

Answer 1

Syndrome: Retinablastoma

Major tumor: Retinablastoma, osteosarcoma

Question 2

TP53

Answer 2

Syndrome: Li-Fraumeni Syndrome

Major tumor: Soft-tissue sarcoma, glioma, leukemia

Question 3

APC

Answer 3

Syndrome: Familial adenomatous polyposis (FAP)

Major tumor: Colorectal Cancer

Question 4

MSH2,MLH1,PMS1/2

Answer 4

Syndrome: Hereditary nonpolyposis colon cancer (HNPCC)

Major tumor: colorectal cancer

Question 5

BRCA1/2

Answer 5

Syndrome: Familial Breast/ovarian cancer

Major tumor: Breast and ovarian cancer

Question 6

VHL

Answer 6

Syndrome: Bon Hippel-Lindau Syndrome

Major tumor: Hemangioblastoma, pheochromocytoma, renal cell carcinoma

Question 7

NF1

Answer 7

Syndrome: Neurofibromatosis type 1

Major tumor: Neurofibroma , astrocytoma, sarcoma, leukemia

Question 8

NF2

Answer 8

Syndrome: Neurofibromatosis type 2

Major tumor: Schwannoma, meningioma, ependymoma

Question 9

TSC1/2

Answer 9

Syndrome: Tuberous sclerosis complex

Major tumor: cortical dysplasia, renal angiomyolipoma

Question 10

WT1

Answer 10

Syndrome: WAGR (Wilms Tumor, aniridia, Genitourinary anomalies, growth retardation)

Major tumor: wilms tumor

Question 11

MEN1

Answer 11

Syndrome: Multiple Endocrine Neoplasia 1

Major tumor: Islet Cell adenoma, pituitary adenoma, parathyroid adenoma

Question 12

Wilms tumor

Answer 12

Autosomal dominant inheritance

results from the loss of function in the WT1 gene on chromosome 11 which encodes a transcription factor important in the control of cell growth and differentiation

Question 13

Two hit hypothesis: sporadic cancers

Answer 13

“two hits”(mutations) are needed for tumor progression

A mutation occurs in a tumor suppressor gene on one homolog in one cell

the second mutation occurs in the same gene(2nd copy) in the same cell

leads to loss of all tumor suppressor activity

Question 14

Two hit hypothesis Familial cancers

Answer 14

The 1st hit is present in every cell inherited. only one more hit needed for tumor initiation

Question 15

Mechanisms producing the 2nd hit

Answer 15

non disjunction

mitotic recombination

gene deletion

point mutation

Question 16

what are the genes needed for regulation of the G1-S checkpoint

Answer 16

RB

CDK4,

Cyclin D gene

CDKN2A

Question 17

What is this image of?

Answer 17

White pupillary reflex in the eye

indicative of retinoblastoma

Question 18

What happens if there is loss of function of the p53 protein?

Answer 18

net cell growth

increased mutation frequency

Question 19

what are the differences between familial and sporadic cancer forms?

Take some time to think about it

Answer 19

Familial/mendelian

• Germline mutation
• Multiple tumors
• bilateral
• early onset

Sporadic

• starts with normal gene
• single tumor
• unilateral
• later onset

Question 20

Li-Fraumeni Syndrome

Answer 20

Inherited mutation of p53

Increases risk of cancer at young age
several types of cancer

1st hit is maternally inherited, 2nd hit is somatic

Question 21

Familial Adenomatous Polyposis

Answer 21

Autosomal dominant inheritance

Affects Beta catenin involved in growth control pathway
Allows Beta catenin to not be degraded and grown in the absence of the WNT signal