JAK-STAT/TGF-beta/Wnt

Question 0

Name three types of cytokines

Answer 0

Interleukins (IL), Interferons (IFNs), and Colony-stimulating factors (CSFs)

Question 1

What are cytokines?

Answer 1

Family of soluble mediators of cell to cell communication. Required for natural and acquired immunity, hematopoiesis and inflammation as well as neural and embryonic development.

Question 2

Describe the mechanism of JAK-STAT signaling

Answer 2

Binding of cytokine links two receptors into dimer. These receptors are associated with JAK. The JAK dimer autophosphorylate and attract two STAT proteins. The two STATs are phosphorylated and dissociate to make a free dimer. The STAT dimer the translocates to the nucleus to affect Tx

Question 3

T or F: Erythropoietin acts on a JAK-STAT pathway

Answer 3

T

Question 4

What is erythropoietin?

Answer 4

Cytokine that induces differentiation of RBC.

Question 5

T or F: Erythropoietin receptors are crucial for development

Answer 5

T

Question 6

Which pathways can Epo activate?

Answer 6

JAK STAT leading to activation of STAT5, Ras, Phospholipase C, or PI 3-kinase

Question 7

What is TGF-beta?

Answer 7

Transforming growth factor that regulates many developmental processes such as mesenchymal differentiation, skeletal morphogenesis and skin formation

Question 8

Describe the TGF beta pathway mechanism

Answer 8

Dimerization of TWO different types of receptors (Type I and Type II) that dimerize and phosphorylate two different proteins that cooridinate with SMAD 4 to make a trimeric Tx factor

Question 9

Pancreatic cancer is very common in what signaling protein?

Answer 9

Smad

Question 10

T or F: TGF-beta is often over expressed in cancer and their associated fibroblasts

Answer 10

T

Question 11

What is the WNT pathway?

Answer 11

Wingless INT-1 pathway important during embryonic development differentiation and that regulates somatic stem cells. Aberrant WNT pathways lead to neoplastic proliferation.

Question 12

What sort of cells does WNT regulate?

Answer 12

Intestinal epithelial stem cells, Hematopoeitic stem cells, hair follicle stem cells, mesenchyal stem cells

Question 13

Describe the general mechanism of Wnt pathway

Answer 13

Involved in the degredation of beta-catenin. No Wnt, beta-catenin is degraded via APC. WNT turns off beta-catenin degredation leading to Tx

Question 14

What is familial adenomatous polyposis (FAP)

Answer 14

Mutation in the APC proteins in the WNT pathway resulting in run away cell profileration due to overexpression of beta-catenin