BIOL 2160 Chapter 6

Genetic damage can result from a mutation in 1 or 3 types of genes. What are these genes?

proto-oncogenes , tumor-suppressor genes, and caretaker genes.

What do Proto-oncogenes do?

normally promote cell division, but are changed into oncogenes by mutations that make the gene excessively active.

What do Tumor-suppressor genes do?

normally restrain growth. Mutations cause inactivation of these genes, allowing excessive cell division to occur.

What do caretaker genes usually do?

normally protect genome

When caretaker genes are inactivated, mutations in the genome ___________.

accumulate

What are the Environmental substances that induce cancer-causing mutations in cells called?

carcinogens

Name 3 carcinogens.

UV radiation (excessive sunlight)

Tobacco

Asbestos

Alcohol

Benzene

Lead

Nickel

Countless other chemicals...

What is the virus that causes warts on the skin, mouth, genitals, and larynx called?

HPV

What percentage of sexually active people already have HPV?

3/4

naturally clears up in 1-2 years

What percentage of women will get HPV in their lifetime? how many female students will get HPV during their college years?

80%

60%

HPV causes what percentage of all cervical cancers?

90-98%

In about 10% of women, HPV remains in the cervix and increases _______ ________.

cervical cancer

T/F women that have HPV are very likely to develop cervical cancer/

False. most women with HPV will not develop CA

What are some factors that increase the risk of contracting cervical cancer?

increasing age, smoking, and lowered immunity.

About what percentages of cervical CA will not be prevented by the HPV vaccine?

30%

T/F: Gardasil protects women from getting cervical cancer even after they have been exposed to the HPV virus.

false

What is the 3rd most common type of cancer in women?

cervical cancer

Regular pap smears can reduce the date rate due cervical cancer by what percentage?

70%

What is the viral protein that spans the plasma membrane and forms a dimer or trimer which will eventually lead to cervical cancer?

E5

What is the protein that plays a key role in angiogenesis?

PDGF

Platelet-derived growth factor

E5 polypeptides can form stable complexes with one endogenous receptor for ______.

PDGF

What does E5 essentially cause in the body that makes it cancerous?

Causes receptors to dimerize and acts as an on switch. Activates more cell division

Which protein is present in almost all cancer cells? Are they inactivated or activated?

inactvated Rb

What inhibits p53 activity?

E6

What inihbits Rb?

E7

Does the HPV vaccine contain any virus? What does it contain?

no

capsid protein L1

What do Hep B and C ciruses cause in the body?

liver infections that lead to cancer

What perentage of liver cancers in the US are due to Hep B and C?

30%

Mutations usually occur in what kind of cells? Can they be passed on to an offspring?

somatic

yes, if they occur in germ line cells. Doesnt happen often

Why do most cancer occur later in life?

takes many years to acquire multiple mutations necessary for tumor formation

What is the 5th leading cause of cancer DEATH in women?

ovarian

8th most common form of cancer in women?

ovarian

The process in which an ovarian follicle ruptures, and discharges an ovum (egg), that bursts through the wall of the ovary is called?

ovulations

What causes ovarian cancer?

mutations in the genes that encode the for the cell division when repairing the walls of that ovaries

Does the "the pill" inhibit menstruation or ovulation? What hormones does it contain?

ovulation

progestin and estrogen

The pill can reduce contracting ovarian cancer by what percent?

50%

The longer the will is taken the _____ the risk of developing the disease even after so many years after taking it regularly.

lower

Natural doesnt always mean ______.

healthy

What is the cancer forming process called?

oncogenesis

A rapidly proliferating cell type that escapes normal growth restraints and stimulates the growth of vasculature to obtain oxygen is called?

Tumor

In terms of caner, which cells are the most dangerous of developing mutations?

skin cells, ovarian cells.

Cells that proliferate quickly

A case in which cells from the primary tumor migrate to new sites where they can form secondary tumors is called?

metastasis

Tissues are more resistant if they produce:

anti-proliferative factors:

inhibitors of proteolytic enzymes:

anti-angiogenesis factors:

What are some properties of a cancer cell?

changes in cell morphology- layers of cells on top of each other

changes in membrane properties- interactions change

growth changes

secretion of plasminogen activator- breaks down basal lamina

loss of actin microfilaments

nucleoli enlarged

Normal Ras protein functions in signal tranduction pathways are activated by ______ ________.

growth factors

In RasD, the glycine that is usually found in the 12th position was replaced by which amino acid?

valine

RasD breaks down _____ very ______.

What does this cause?

GTP; slowly

remains in the on position for too long

Any gene that encodes a protein capable of transforming normal cells into cancer cells is called?. i.e.: RasD

oncogene

A normal cellular gene, that, upon mutation, can become an oncogene is called?

proto-oncogene

T/F: Loss of Ras always leads to cancer

false

cancer is a multi hit phenomenon.

Mutations in non-dividing cells are ________.

aren't usually cancerous.

The brain doesn't have proliferating cells, why is then that people can develop brain cancers?

the glial cells divide, these are the ones that become cancerous

The recruitment of new blood vessels is required for the growth of all tumors. What is this called?

angiogensis

About how many mutations are thought to be needed for most cancers to occur?

5-6

What is the interaction of two or more agents or forces so that their combined effect is greater than the sum of their individual effects called?

synergy

What two oncogenes have synergistic effects? (example in class)

Myc and Ras

The Family of proteins that control progression of cells through the cell cycle is called? These don't have enzymatic activity, so what does it rely on?

Cyclins

cyclin dependent kinases

At which checkpoint is where the cell divides?

M checkpoint

What regulates cell cycle checkpoints?

cyclins and cyclin dependent kinases

Loss-of-function mutations occur in these genes.

tumor suppresor genes

50% of all human tumors carry mutations in the ______ tumor suppresor gene

p53

What does p53 encode for?

stress response regulator

p53 is usually ________, but a damaged one is usually destroyed by ________.

ubiquitinated; proteasome

Which checkpoint prevents cells with damaged DNA from entering the S phase?

G1

What is the 5th most common cause of ALL cancer deaths?

Breast

2nd most common type of cancer?

breast

most common type of cancer?

lung

Breast cancer develops Due to inheritance of one mutant allele of ______ or ______ genes (Breast cancer, early onset), tumor-suppressor gene. Mutation in at least one of these genes results in what percentage of developing cancer?

BRCA 1

BRCA 2

60%

What is the drug that inhibits estrogen receptors and is used to treat breast cancer?

tamoxifen

is chemotherapy the primary treatment for cancer?

the last resort

Patients that have breast cancer are given _____ to promote WBC growth and _______ to promote RBC.

G-CSF

Erythropoietin