Basic Genetics of Neoplasia

Question 1

Where is genetic information stored?

Answer 1

In DNA (deoxyribonucleic acid)

Question 2

What is the function of genes?

Answer 2

They code for a protein

Question 3

What is the function of a protein?

Answer 3

It has a task (from the gene) and does the task

Question 4

What do DNA repair genes do?

Answer 4

Continuously read through genetic code to check for error

Question 5

Why would a codon thats supposed to read ACC but is read ATC a problem?

Answer 5

The cellular function will be compromised by this mistake and must be fixed.

Question 6

In this situation: A codon thats supposed to read ACC but is read ATC.

How would DNA repair genes fix this?

Answer 6

Through a single nucleotide base change due to an insertion, deletion, or subsitution

Question 7

What targets DNA repair genes so that you can’t check for errors?

Answer 7

Carcinogens

Question 8

What are the categories relating to tumors?

Answer 8

• Proto-oncogenes

- Tumor suppressor genes

Question 9

Proto-oncogenes?

Answer 9

Enhance cell division (good to have because they oppose homeostasis).

They are normal genes that become cancer-causing genes if mutated.

Question 10

What are proto-oncogenes associated with?

Answer 10

Gene overactivity

Question 11

What occurs if proto-oncogenes become mutated?

Answer 11

You end up with uncontrolled cell growth (defective protein -> defective growth) -> Tumor

Question 12

What are tumour suppressor genes?

Answer 12

Inhibit cell division

Question 13

If mutated what does the tumor suppressor genes cause?

Answer 13

They cause uncontrolled growth and tumor formation

Question 14

What are tumor suppressor genes associated with?

Answer 14

gene underactivity

Question 15

What is TP53?

Answer 15

A gene that causes apoptosis of cell if DNA damaged.

Question 16

What does TP53 code for?

Answer 16

P53 (protein)

Question 17

What is the main target for DNA repair genes?

Answer 17

Cancer

Question 18

Oncogenes?

Answer 18

Cancer causing genes

Question 19

What do oncogenes promote?

Answer 19

Malignant growth

Question 20

What do you name tumors based on?

Answer 20

The tissue of origin

Question 21

Which tumors usually have the suffix “-oma”?

Answer 21

Benign

Question 22

Which tumors have the suffix “-carcinoma”?

Answer 22

Epithelial origin, malignant

Question 23

Which tumors have the suffix “-sarcoma”?

Answer 23

Mesenchyme origin, malignant

Question 24

What kind of tumor is the following?

Adenoma

Answer 24

Benign tumor in glandular epithelium (‘adeno’=glands)

Question 25

What kind of tumor is the following?

Adenocarcinoma

Answer 25

Malignant tumor in glandular epithelium

Question 26

What kind of tumor is the following?

Chondroma

Answer 26

Benign cartilage

Question 27

What kind of tumor is the following?

Chondrosarcoma

Answer 27

Malignant cartilage

Question 28

How often does a tumor double in size?

Answer 28

Roughly every 120 days (approximately 3x a year - every 4 months)

Question 29

How long does it take for a tumor to become clinically detectable?

Answer 29

10 years (30 doublings)

Question 30

How big does a tumor have to be in order for it to be clinically detectable and how is it detected?

Answer 30

1 cm (however exceptions do exist) by a physical exam, chest X-ray etc