Pathophys 5

Question 1

What’s tumour invasion?

Answer 1

The active migration of neoplastic (Tumour) cells out of their tissue of origin and into adjacent tissues of different types

Question 2

What is the 3 step process of cellular invasion?

Answer 2

Cell attachment—>enzyme degradation of ECM—>cell migration

Question 3

What is cell adhesion?

Answer 3

Cell connections involve between multiple Ligands and cell adhesion receptors

Question 4

What is the composition of the extra cellular matrix?

Answer 4

Cells (fibroblasts, smooth muscle cells, chrondroblasts, osteoblasts, water)

Question 5

Collegen network + what? =co gel

Answer 5

Non fibrillation matrix

Question 6

What is the structure of the ECM?

Answer 6

Collegen
Elastin
Proteoglycans
Structural glycoproteins (fibronectin, laminin)

Question 7

What connects Individual cells?

Answer 7

Cell adhesion receptors, enable cells to recognise and bind molecules on other cells or in the extra cellular matrix (ECM)
Make cells stick to other cells
Activate intracellular signalling pathways (primarily for cell death)

Question 8

5 adhesion molecules

Answer 8

1. Intigrin family
2. Selectin family
3. Immunoglobulin superfamily
4. cadherin family
5. mucin like family

Question 9

What is the abbreviation for cell adhesion molecules?

Answer 9

CAM

Question 10

Cell adhesion receptors can form:

Answer 10

1-homophillic adhesions-between the same type of molecules (eg, cadherins)
2-heterophillic adhesions-between different types of molecules (selectins)

Question 11

What cell adhesion receptor mediates cells?

Answer 11

Intergrins

Others mediate cell to cell adhesion

Question 12

What is an example of an intergrin?

Answer 12

Avb6

Question 13

Where is avb6 expressed?

Answer 13

Only on epithelial cells and can be regulated

Question 14

Does the level of avb6 increase or decrease when there is a wound?

Answer 14

Increase

Question 15

What happens to avb6 in squamous cell carcinoma (SCC)

Answer 15

avb6 is upregulated on squamous cell carcinoma

Question 16

When avb6 has increased expression on SCC what specifically happens?

Answer 16

Cell adhesion is increased
Cell migration is increased
Production of enzymes that destroy the basement membrane
SCC invasion through membrane

Question 17

What do cadherins do?

Answer 17

Mediate Ca2+ dependant homophillic cell to cell adhesion which is used in organ formation, form desmosomes and adherens junction
Critical role in development

Question 18

What happens if there is a loss of e cadherin expression?

Answer 18

Mutations, lead to cancer

Question 19

What are the three extracellular proteinases in cancer?

Answer 19

1.Cathepsins–>CTS (cathepsin B, CTS S, CTS D)
2.matrix metalloproteinases (MMP’s)
Eg, gelatinases
3.serine proteinases eg, plasmin

Question 20

What are MMPs roles in tumour progression?

Answer 20

Degradation of matrix barriers
Release of growth factors
Plays a role in morphogenisis and tissue repair

Question 21

What are MMPs?

Answer 21

Zinc binding enzymes secreted as proenzymes

Activated in the ECM through cleavage located in the amino terminal domain

Question 22

How is the MMPs function maintained?

Answer 22

By endogenous inhibitors of the MMPs, called tissue inhibitors of metalloproteinases (TIMPS)

Question 23

What is metastasis?

Answer 23

The transfer of disease from 1 organ or part of an organ to another not directly connected with it