Cancer

Question 1

Similar to tRNA, which other RNA has a characteristic hairpin loop

Answer 1

microRNA (miRNA)

Question 2

Both the siRNA and miRNA have approximately how many nucleotides in length

Answer 2

22

Question 3

Which RNAs silence genes by interrupting expression between trasncription and translation

Answer 3

siRNA and miRNA

Question 4

These RNA sequence are transcribed from enhancer regions of the DNA and appear to be associated with increased transcriptional activity

Answer 4

Enhance RNA (erNA)
*a very new area of research and its physiological function has not been conclusively determined yet

Question 5

A disease in which gene expression is abnormal

Answer 5

Cancer

Question 6

Term for teh development of cancer

Answer 6

Oncogenesis

Question 7

This term describes any abnormal proliferation of cells

Answer 7

Tumor

Question 8

These tumors remain localized

Answer 8

Benign tumors

Question 9

These tumors can invade other organs and tissues in the body

Answer 9

Malignant tumors

Question 10

The process in which malignant tumors invade and spread around the body

Answer 10

Metastasize

Question 11

The first step in oncogenesis which involves changes that allow a single cell to proliferate abnormally

Answer 11

Tumor initiation- this means that teh cell must envelop the ability to bypass regulatory steps of the cycle that normally help to restrain mitotic proliferation

Question 12

Occurs as a cell develops the ability to proliferate even more aggressively, such that its descendants are preferentially selected for and come to predominate teh growing tumor.

Answer 12

Tumor progression

Question 13

Malignant cells often undergo mutations allowing them to secrete ________ _______ to stimulate their own growth, ___________ that digest components of the extracellular matrix and favor metastasis, and __________ _________ that promote the formation of new blood vessels to feed the growing tumor

Answer 13

Growth factors; proteases; growth factors

Question 14

Formation of blood vessels

Answer 14

Angiogenesis

Question 15

Oncogenesis is associated with mutations that occur by random chance or as a result of mutagenic compounds known as

Answer 15

Carcinogens

Question 16

Compounds that help induce the growth of proliferative cells by stimulating the activity of proteins involved in growth and division

Answer 16

Tumor promoters

Question 17

The genes involved in oncogenesis can be divided into?

Answer 17

Oncogenes and tumor suppressor genes

Question 18

These function to promote abnormal growth and proliferation, leading to cancer

Answer 18

Oncogenes

Question 19

These genes function to prevent tumorigenic properties

Answer 19

Tumor suppressor genes

Question 20

Cancer- causing viruses. Give examples

Answer 20

Tumor viruses

Ex. Hepatitis B and C, papilloma viruses, Epstein-Barr virus

Question 21

This tumor invades through the basement membrane and may spread to other tissues and organs

Answer 21

Malignant tumor

Question 22

T or F. Benign tumors can be fatal.

Answer 22

True. It can press on nerves or blood vessels. Benign tumors can certainly be fatal

Question 23

Tumorigenesis starts from just one cell that is able to bypass normal ________ _________ ____________ and begin to divide abnormally

Answer 23

Cell cycle checkpoints

Question 24

T or F. Tumor usually starts with an accumulation of mutations in critical genes that together allow a mutinous cell to divide when it shouldn’t evading normals controls on cell division and growth.

Answer 24

True

Question 25

De novo mutations during DNA replication occur what rate

Answer 25

1 error / 100,000 bp (but proofreading enzymes catches 99% of these errors) Overall rate: 1 / 10,000,000

Question 26

What tissues are prone to cancer?

Answer 26

Tissues that divide frequently such as epithelial tissues, liver, or digestive tract *cancer is less likely to occur in cells that divide infrequently such as neurons

Question 27

Most of the brain tumors are __________ or _________ from other parts of the body

Answer 27

Gliomas, metastases

Question 28

Mutagenic agents that can cause cancer. Give examples

Answer 28

Carcinogens | Ex. Chemical mutagens, radiation (X-rays, gamma rays)

Question 29

UV radiation is known to produce what kind of mutation?

Answer 29

Pyrimidine dimers - could result to lasting DNA damage

Question 30

Characterized by highly dysregulated genes expression, favoring the synthesis of RNA and proteins that promote the growth and survival of the tumor

Answer 30

Cancer

Question 31

Mutant genes promoting abnormal cell growth leading to cancer

Answer 31

Oncogenes

Question 32

Genes protecting against abnormal cell growth whose impaired function can promote cancer

Answer 32

Tumor suppressor genes

Question 33

The non mutated oncogenes are

Answer 33

Proto-oncogene

Question 34

Oncogenes tend to occur to those that code for

Answer 34

Growth factors, growth factor receptors,transcription factors, protein kinases, other signaling molecules- especially those that play a role in cell growth and differentiation *they are also found in cancer-causing viruses

Question 35

Cancer-causing viruses do what?

Answer 35

They either insert oncogenes directly or upregulate existing proto-oncogenes in the host genome

Question 36

Hepatitis B and C causes what cancer

Answer 36

Liver cancer

Question 37

Papilloma viruses cause what kind of cancer

Answer 37

Cervical and anogenital cancers

Question 38

Epstein-Barr virus cause what kind of cancer

Answer 38

Burkitt’s lymphoma and Nasopharyngeal carcinoma

Question 39

TP53 gene

Answer 39

Encodes the p53 tumor suppressor protein Known as the “guardian of the genome” *if downregulated or nonfunctional, damages can evade checkpoints and mutations can propagate through generations

Question 40

Mutations in p53 have been implicated in atleast _________ percent of human cancers

Answer 40

50

Question 41

BRCA 1 and BRCA 2

Answer 41

Play important roles in repairing DNA damage | -mutations in these genes are heritable and are associated with greatly increased risks of breast and ovarian cancer

Question 42

BRCA 1/2 genes mutations in females are associated with up to ________ percent risk of developing breast cancer by age 90. As well as increased risk of ovarian and other cancers

Answer 42

80%

Question 43

These genes are associated with proliferation, bypass of cell cycle checkpoints, and avoidance of DNA repair

Answer 43

Oncogenes

Question 44

These genes limits on mitosis, cell cycle regulation, and DNA repair

Answer 44

Tumor Suppressor genes

Question 45

_________ of oncogenes or ________ of tumor suppressor genes

Answer 45

Activation; dysfunction

Question 46

Why do anti-mitotic chemotherapeutic agents commonly cause gastrointestinal side effects

Answer 46

Cells of the GI tract experience a high rate of turnover