3.1 unit quiz

x-ray

Electromagnetic radiation
sends individual photons through body
shows dense structures (bone)
2d image
examines bones, teeth, lungs, breast, heart, blood vessels, digestive tract

CT scan

a series of x-ray photographs taken from different angles combined by computer into a composite representation of a slice through the body
computerized axial tomography
examine chest, abdomen, pelvis, spine, other skeletal structures

MRI

uses powerful magnets and radio waves
scans the body by turning small magnets off and on
produces detailed images of soft tissues
cross-sectional images of body
examine brain, spine, joint, abdomen, blood vessels, and pelvis

bone scan

nuclear medicine scan using radioactive dye to visualize bones
machine passes gamma camera over body to record tracer pattern in bones
2d images
finds abnormal bone metabolism

Proto-oncogenes

the corresponding normal cellular genes that are responsible for normal cell growth and division

oncongenes

gene in which certain conditions can transform a cell into a tumor cell

tumor suppressor genes

make proteins that stop cell division and kill cells
regulates cell division

mutated tumor suppressor genes

the protein it encodes is not produced or does not function properly, and as a result, uncontrolled cell division may occur

DNA repair genes

a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome

mutated DNA repair genes

increase genomic instability and mutation

normal cells

-replicate in an organized manner
-die after a limited number of cell divisions
-distinct features that enable them to perform their specific function
-same size and shape
-one small nucleus with common shape
-arrange themselves in an organized manner
-well-defined tissue boundaries

cancerous cells

-can replicate indefinitely
-lose specialized features, cannot perform proper functions
-vary in size + shape
-large, variably shaped nuclei, often multiple nuclei
-disorganized arrangement, no clear borders

Levels of Abnormality

normal, hyperplasia, mild dysplasia, carcinoma in situ, cancer

hyperplasia

contains a higher than usual number of cells
cell structure and orderly arrangement of cells are what is seen in healthy tissue cells

mild dysplasia

The tissue shows loss of standard tissue arrangement and cell structure, which is not extreme, thus is not considered cancerous.

carcinoma in situ

shows uncontrolled growth of cells and aberrant tissue arrangement and cell structure
changes remain within original location

cancer

shows uncontrolled growth of cells and aberrant tissue arrangement and cell structure
migrate beyond the original location

upregulation

more mRNA is produced in gene than normal

down regulation

less mRNA is produced in gene than normal

Isolate mRNA from cells of interest

step 1 of DNA microarray
these cells will be from healthy and cancerous tissue

create cDNA

step 2 of DNA microarray
an enzyme transcribes the mRNA and DNA to create complimentary DNA

label cDNA to be visualized in the microarray

step 3 of DNA microarray
helps identify regulation of genes

Hybridization

step 4 of DNA microarray
as the cDNA washed over the chip it will hybridize (bind) to any well that has its complimentary strand

analyze the microarray

step 5 of DNA microarray
results

combined cDNA images

step 6 of DNA microarray
to show what genes need to be monitored
where genes are not regulated, normal, increased, decreased, or not expressed

green color in microarray

healthy cell

red color in microarray

cancer cell

yellow color in microarray

mRNA expressed equally in both cells

white color in microarray

no mRNA expressed in either cell

Human carcinoembryonic antigen (CEACAM6)

This gene codes for a protein that is located in the extracellular matrix. This protein is involved with adhesion between cells and is thought to be a proto-oncogene and when over-expressed is an oncogene.
(increased)

Surfactant protein B (SFTPB)

This gene codes for proteins that assist breathing and is not involved in the regulation of the cell cycle.
(normal)

p53 tumor suppressor (TP53)

This gene codes for a protein that is located in the mitochondria and in the nucleolus. This protein is involved with cell cycle checkpoints. This gene is a tumor suppressor gene and is thought to be the "Guardian of the Genome."
(decreased)

SRY

This gene codes for a protein that is located in the nucleus. The protein that this gene codes for is testis-determining factor (TDF) which initiates male sex determination. This protein has no function in lung cells.
(no expression)

Cytochrome P450 (CYP1A1)

This gene codes for a protein that is located in the endoplasmic reticulum. The protein catalyzes reactions involved in drug metabolism and synthesizes cholesterol, steroids, and other lipids. The expression of this protein is induced by some polycyclic aromatic hydrocarbons (PAHs), some of which are found in cigarette smoke.
(increased)