Neoplasia

Question 1

what is an oncogene

Answer 1

a gene whose activated product causes growth

Question 2

what is a tumor suppressor gene

Answer 2

a gene whose product prevents growth

Question 3

true or false: benign tumors are always harmless

Answer 3

false: benign means that the neoplasm doesn’t move other parts of bodies, can cause symptoms depending on location and size

Question 4

two most common epithelial malignant neoplasms

Answer 4

adenocarcinoma (glands that line inside of organs) and squamous cell carcinoma (middle and outer layers of skin)

Question 5

four types of malignant neoplasms

Answer 5

epithelium (skin), sarcoma (soft tissue), hematolymphoid (blood and lymph system), nervous system (brain and spinal cord)

Question 6

two types of malignant hematolymphoid neoplasms

Answer 6

leukemia, lymphoma

Question 7

what are the 8 hallmarks of malignant neoplasm

Answer 7

self-sufficiency in growth signals
insensitivity to growth inhibitors
altered cellular metabolism
evasion of apoptosis
immortality
sustained angiogenesis
ability to invade and metastasize
ability to evade human immune response

Question 8

what protein is first activated by growth factor

Answer 8

RAS

Question 9

what kind of proteins does the tumor suppressor gene activate

Answer 9

GAP (inactivates RAS), PTEN (inactivates PI3K)

Question 10

what gene mutation can lead to breast and stomach cancers

Answer 10

Her2

Question 11

what gene mutations can lead to lung cancers?

Answer 11

EGFR, ALK

Question 12

what percentage of human cancers involve the growth factor, receptor, or RAS protein mutations

Answer 12

20%

Question 13

what gene mutation leads to skin, lung, colorectal, thyroid cancers

Answer 13

BRAF

Question 13

what does the BRAF mutation do

Answer 13

cause continuous production of RAF leading to cell growth

Question 13

how do cancers alter cellular metabolism

Answer 13

more interest in reproduction than production of energy so recruit neighboring cells to switch over to anaerobic glycolysis to harvest lactate product for carbons to continue fueling anaerobic process (Warburg effect)

Question 14

what actions does p53 activate

Answer 14

senescence (sleep), DNA repair, inhibit growth, apoptosis

Question 14

what is p53

Answer 14

tumor suppressor gene that provides surveillance on cell’s genetic material and directs cell in how to handle genetic damage

Question 14

how do malignant neoplasms avoid apoptosis and remain immortal

Answer 14

Tumors activate telomerase to regenerate telomeres at end of DNA stands so cell never receives signal to undergo apoptosis for damaged/mutated DNA

Question 15

What are vascular stimulator genes

Answer 15

VEGF, bFGF

Question 16

3 ways malignant neoplasms can spread

Answer 16

seeding of adjacent surfaces, lymphatic spread, hematogenous spread

Question 17

what do MHC class I receptors signal

Answer 17

alerts immune system that cell is infected or broken in some way

Question 18

how do tumor cells evade immune system

Answer 18

don’t display antigen on MHC class I receptor, stop making MHC class I receptors, make immunosuppressive (anti-inflammatory) cytokines that kill T cells

Question 19

define initiation phase of carcinogen exposure

Answer 19

electrophilic intermediates bind to DNA and creates permanent DNA lesion

Question 20

define promotion phase of carcinogen exposure

Answer 20

cell will replicate uncontrollably with altered DNA, ultimately leading to malignant neoplasm

Question 21

how does ionizing radiation (UV and X-rays) increase risk of cancer

Answer 21

Waves excite electrons in our bodies causing them to cling to water. this breaks up the water molecules into free radicals which can eventually damage and break DNA

Question 22

What does TNM mean when it comes to tumor staging

Answer 22

T: tumor (primary), how big it is
N: number of lymph nodes involved
M: metastasis, how far it traveled