Medical Interventions Unit 3.1

protooncogenes

A normal cellular gene corresponding to an oncogene; a gene with the potential to cause cancer but that requires some alteration to become an oncogene.

Protooncogenes function

Proto-oncogenes are normal genes that play a role in cell growth, division, and differentiation.

Difference between proto oncogene and oncogenes

A proto-oncogene is a normal gene that helps cells grow and divide, while an oncogene is a mutated proto-oncogene that can cause cancer.

p53

Regulates cell division, DNA repair, and triggers apoptosis, all functions that are important in developing cancer

Copies of p53

Having only 1 copy can increase the risk for cancer in an individual

Exhaustive list of mutation causes

errors during DNA replication, environmental factors like where you live, and what the soil, sun, and anything else is like. Lifestyle choices like what you eat, if you smoke, how often you exercise, and age can also be a factor as cancer is more likely in the later years. Heredity can also play a role: what kind of genes run in the family, BRCA 1 and BRCA 2 for example, radiation, chemicals, and some viruses. 400 different miscellaneous things that can be added to food. Stuff that makes apple waxy, or cereal crunchy can also cause cancer, especially sine the number of different sands has increased to 400.

Human Papilloma Virus

Can cause cancer

Promoters causing cancer

Translocation of a promoter: promoter can be moved before a proto-oncogene which makes the proto-oncogene turn on regularly, which increases the risk of cancer

Methylation

adds a methyl group to DNA, RNA or protein and plays a role in regulating gene expression.

Hypermethylation

Hypermethylation of tumor suppressor genes can lead to cancer because the tumor suppressor gene is hypermethylated, meaning it is silenced

Mutations in protooncogenes

When protooncogenes become mutated and lose their function, it could lead to unregulated cell division which can cause cancer.

Nickname for p53

Guardian of the genome

Cancer detection that is better than man-made methods

Canines. They can detect lung cancer early

BRCA1 and BRCA2

BRCA1 and BRCA2 help prevent uncontrolled cell growth and tumor formation.

Mutations in BRCA 1 and 2

When a person inherits a mutated BRCA gene, they are at a larger risk for cancer

Cancer can affect

any and everybody

Cancers that are on the rise

colon cancer, eyelash cancer

Phthalates

a class of chemicals that may be carcinogenic to humans. Found mostly in nail polish, perfumes, deodorants, hair gels, shampoos, soaps, hair sprays, and body lotions

Cancer cells in a culture

can reproduce forever, and are known to accumulate a few more mutations along the way

Contact Inhibition in cancer

Cancer cells don't have contact inhibition, they don't respect boundaries of cells and are not inhibited by contact

Cancer cells growth conditions

They can grow in mutiple mediums, and they also grow on to of one another. Can grow in less stringent conditions.

Visuals of a cancer cell

Irregular shapes in cells, larger nucleus and can have multiple nuclei. Have more chromosomes than normal

Pre cancerous cells

Look puffy and large, but are not yet cancer.

Imaging systems

X-ray, CT Scan, MRI, and Bone Scan

X-ray (Ad/Dis)

dense structures like bone, appear white, structures that contain air will appear black, while muscle, fat, and fluid will appear gray. Quick painless, noninvasive and inexpensive but exposes the people to radiation.

CT (Computerized Tomography) (Ad/Dis)

Used to image bone, soft tissue, and blood vessels all at the same time. Painless, noninvasive fast and simple. Can be performed if a medical device is implanted. But has ionizing radiation exposure.

MRI (Magnetic Resonance Imaging) (Ad/Dis)

poses almost no risk, does not involve exposure to ionizing radiation, more accurate images of soft tissure structures are more likely to identify and accurately characterize diseases, but cannot contain any implanted medical devices.

Bone Scan (Ad/Dis)

Non invasive, extremely sensitive to abnormalities and variations in bone metabolism and can scan the entire skeleton but cannot determine cause of bone metabolism abnormalities also small amount of radiation exposure.

X-ray

electromagnetic radiation is sent to the body

CT scan

series of X-ray views taken from many different angles are combined to produce cross-sectional images of the bones and soft tissues inside your body.

MRI

MRI uses powerful magnets and radio waves.

Bone Scan

a nuclear imaging test. tiny amounts of radioactive materials called tracers (radionuclides). usually done at an older age

More about X-rays

the cheapest way to look for fluid in the lungs, can look for blockages

More about CT scans

a whole bunch of X-rays from different angles, does soft tissue and hard tissue, not the safest

More about MRIs

safer, a giant magnet, electromagnet, lines up all cations and ions in the body and gets a pic. Great for soft tissue

More about Bone Scans

Radioactive tracers soaked up by the bone to identify areas of high metabolism. A darker color can indicate cancer, bright white can indicate bone rebuilding

Microarrays

Measure expression levels of thousands of genes at once and what genes are turned on or off in cancer cells and normal cells.

How Microarrays work

collect mRNA, convert to complementary DNA using reverse transcriptase.

Microarrays and correlation

Used to determine the correlation between the expression levels of two genes based on a number between -1 and 1

The four colors on a microarray

RED, GREEN, YELLOW and BLACK

RED

Greater expression (upregulated) in cancer cells than in normal cells. Can indicate the presence of oncogenes and genes involved in cell replication.

GREEN

Greater expression in normal cells and lower expression in the experimental sample (downregulated). Can indicate the presence of tumor suppressor genes.

Downregulated

Gene expression in the cancer is lower than in the normal cell

Upregulated

Gene expression in the cancer cell is higher than in the normal cell.

BLACK

No expression in both cancer and normal cells

YELLOW

Similar levels of gene expression in both cancer cells and normal cells. Usually represents cell function that is needed for both cells like metabolizing and dividing.

Intensity of color

The darker the color, the more expressed the gene was. So dark red means a lot of cancer genes, while light red means not that much.

Colors on microarray translated to numbers

Greater than 1 means more expressed in cancer cells, while less than 1 means less expressed in cancer cells while 0 means expressed in neither, 1 means similar expression

Positive

Genes behaved similarly

Negatively

Genes behaved in opposite ways

Correlation

0 means no correlation, 0 to 1 means not equal but correlation increases in strength as number increases.