Lecture 3 - Cancer

Question 1

By what is the cell cycle controlled?

Answer 1

Cyclins.

Growth factors increase cyclins through CDKs (cyclin-dependent kinases)

Question 2

What is differentiation?

Answer 2

process where cell gains specific characteristics.

usually loses its ability to replicate

Question 3

What is transformation

Answer 3

when a normal cell becomes malignant

Question 4

What is cancer progression?

Answer 4

invasion and destruction of normal tissue by cancer cells

Question 5

What is neoplasm?

Answer 5

tumor that spreads through metastasis from primary to distal site

Question 6

Differences between benign and malignant tumors…

Answer 6

Benign:

• looks like tissue of origin
• slow growth
• encapsulated
• no metastasis
• no necrosis or ulcer
• not fatal
• slight vascularity

Malignant:

• looks different than tissue
• rapid growth
• spreads to other tissue
• metastasis
• necrosis
• recurrence
• fatal
• high vascularity

Question 7

Of what origins?…

1. Carcinoma
2. Sarcoma
3. Lymphoma
4. Leukemia
5. Glioma

Answer 7

1. epithelial (in situ, invasive)
2. connective
3. lymphatic
4. bone marrow
5. glial cells of CNS

Question 8

Cancer grades…

Answer 8

Grade I: well differentiated
II: increased mitosis
III: much variation in size and shape and greatly increased mitosis
IV: no resemblance to tissue of origin

Question 9

What do cancer cells lack?

Answer 9

density-dependent inhibition of growth

Question 10

Manifestations of malignant cells…

Answer 10

local inc in cell #
inc mitosis
inc nuclear size/density
abnormal mitosis and chromes
loss of normal arrangement
variation in cell shape, size, structure, etc
anchorage independent for cell growth

Question 11

What do tumor cells often produce?

Answer 11

Hormones not usually associated with the tissue.

Called tumor markers

Also growth factors, or are independent of GFs for growth

Question 12

Proto-oncogene

Answer 12

a gene that may become an oncogene due to inc expression or mutation

Question 13

oncogene

Answer 13

a gene that has the potential to cause cancer

Question 14

The master tumor suppressor gene

Answer 14

p53

Question 15

Environmental factors that cause altered DNA

Answer 15

tobacco
diet
alcohol
pollution 
UV 
ionizing radiation

Question 16

some oncogenic viruses

Answer 16

Human papilloma virus
Epstein-Barr virus
Hepadenoviruses
Human T leukemia virus

Question 17

Stages of cancer

Answer 17

Initiation: mutation of proto-oncogene or tumor suppressor

Promotion: constant exposure to growth factors or mimics

Progression: now grows in absence of GFs

Immortalization: telomerase activity increases and cancer cells can divide indefinitely

Question 18

Can our immune system recognize cancer cells as foreign?

Answer 18

Yes. Thus our immune system can help and kill malignant cells

Question 19

How can cancer cells escape immune system?

Answer 19

alter TAAs - rid of them, alter, cover

inhibit immune system with produced chemicals

Question 20

Cancer cells are carried to other parts of the body by…

Answer 20

fluid in body cavity
spaces b/w tissues
lymph vessels
blood vessels

Question 21

manifestations of cancer

Answer 21

Pain
Fatigue
Cachexia
Decreased synth of blood cells
   leads to anemia, leukopenia, thrombocytopenia

Question 22

treatments of cancer

Answer 22

chemotherapy
radiation
surgery
immunotherapy
hormone therapy
decrease angiogenesis

Question 23

causes of cancer death

Answer 23

infection
hemorrhage
blood clots
anemia
weakness due to weight loss
loss of function of organs