Chapter 11 Medical Biotechnology

biomarker

typically proteins produced by diseased tissue or proteins whose production is increased when a tissue is diseased

animal models

animal tests thought to be related to human disorders, used for research or drug development; must always be assessed in detail for their validity.

ob gene

Obesity gene. The gene that encodes leptin.

Example of biomarker

PSA (prostate-specific antigen) is released into bloodstream when prostate gland is inflamed. shows prostate inflammation or prostate cancer

FISH (fluorescent in situ hybridization)

fluorescently labeled probes can be used to hybridize denatured chromosome spreads. can detect submicroscopic deletions, translocations and duplications of genes

Chronic Myelogenous Leukemia (CML)

Translocation between chromosomes 9,22) called Philadelphia Chromosomes

amniocentesis

fetus is 16 weeks of age

take sample of amniotic cells, culture and grow them, create karyotype

chorionic villus sampling

fetus is 8-10 weeks

remove a small portion of a layer of cell called the chorionic villus (fetal tissue that helps form the placenta), create karyotype

Karyotype

A display of the chromosome pairs of a cell arranged by size and shape.

Restriction Fragment Length Polymorphisms (RFLP)to detect genetic diseases

mutations mostly happen in specific genes, not abnormalities in chromosome numbers

detective gene sequences may be cut differently by restriction enzymes than their normally bc nucleotide changes

EX: sickle cell disease

Allele specific oligonucleotide (ASO) to detect genetic diseases

mutation that doesn't change restriction site - single nucleotide change in a gene

DNA is isolated, then amplified, and probe with 2 different ASO's (one for normal gene, one for diseased gene)

preimplantation genetic testing

using ASO, PCR, and FISH to screen for genetic defects in the 8 to 32-cell-stage embryos during in vitro fertilization

single nucleotide polymorphisms to detect genetic disease

SNPs - common form of genetic variation in humans

changes protein structure that produces diseases or influences traits in a variety of ways

predict susceptibilities to: stroke, cancer

DNA microarray analysis

track the expression of thousands of genes; used to identify and devise treatments for diseases based on the genetic profile of the disease

protein microarrays

Large number of different proteins applied to a solid support as a series of spots, each containing a different protein; similar to gene chips

oncogenes

genes involved in the growth of cancer cells

tumor suppressor genes

A gene whose protein product inhibits cell division, thereby preventing the uncontrolled cell growth that contributes to cancer.

ctDNA (circulating tumor DNA)

DNA that is released into the bloodstream when tumor cells die

DNA and RNA sequencing

Uses probes/primers to identify genes of interest, may replace microarrays

Single-cell RNA sequencing (scRNA-seq)

examines the genomes or transcriptomes of individual cells, providing a high-resolution view of cell-to-cell variation

Single-cell sequencing (SCS)

Technology that can provide DNA or RNA sequence information from a single cell as opposed to sequencing the genomes from a collection of cells, good for somatic cell mutations and can determine the heterogeneity of tumors

Transcriptome analysis

the study of all expressed genes, uses RNA sequencing

Whole Exome Sequencing (WES)

Genomic technique for sequencing all of the protein coding genes in the genome

Whole Genome Sequencing (WGS)

complete DNA sequence of an organism's genome at a single time; generating accurate reference genomes for microbial identification, and other comparative genomic studies

Pharmacogenomics

customizing medicine by designing effective drug therapy and treatment strategies based on the specific genetic profile of a patient

individuals can react differently to the same drug due to genetic polymorphisms

nanotechnology

area of science involved in designing, building, and manipulating structures at the nanometer scale

nanomedicine

applications of nanotechnology for improving human health

EX: nanodevices that deliver tiny particles that can be used to monitor blood pressure; nanoparticles that can unclog arteries, detect and eliminate cancer cells

Microspheres

nanoparticle that can be filed or coated with drugs. Used to increase drug delivery and effectiveness

resemble phospholipids

Monoclonal Antibodies

purified antibodies that are very specific for certain molecules

EX; cancer cells, arthritis, Alzheimer's, addiction to harmful drugs

making a mAb

1. inject purified antigen into rat

2. makes antibodies

3. mix antibodies with myeloma cancerous cells

4. creates hybridoma

5. divides fast like cancer but makes B cells like antibodies

6. inject back into humans

immunotherapy

a disease treatment that involves either stimulating or repressing the immune response

Hybridoma technology

Entails isolation of B cells and subsequent fusion with myeloma cells

Myeloma cells

rapidly-dividing cancerous plasma cells which are fused with extracted B cells from mice to produce hybridomas

Gene therapy

delivery of therapeutic genes into the human body to correct disease conditions created by a faulty gene or genes

oncolytic viruses

infect and lyse cancer cells, examples used are adenovirus, adenoassociated virus (AAV), influenza, Herpes

vectors for gene delivery

typically rely on viruses as vectors. use viral genome to carry a gene and use virus itself to infect human cells, which includes the gene

CRISPR/Cas 9 examples

Used to remove a defective exon from the Dmd gene in a mouse model of Duchenne muscular dystrophy (DMD)

Used to target and replace the defective clotting Factor IX gene in liver cells to cure mice of hemophilia B

Gene therapy for treating different forms of blindness

Leber's congenital amaurosis (LCA)

CRISPR/Cas9

a unique technology that enables geneticists and medical researchers to edit parts of the genome by removing, adding or altering sections of the DNA sequence using nucleases derived from bacteria

Liposomes

small, hollow particles made of lipid molecules

packaged with gene or drug then injected/sprayed into tissues

RNA interference (RNAi)

A technique used to silence the expression of selected genes. RNAi uses synthetic double-stranded RNA molecules that match the sequence of a particular gene to trigger the breakdown of the gene's messenger RNA to prevent translation

2 delivery approaches of RNAi

1. inject antisense RNA or siRNA directly

2. using plasmid vector that is taken in by cells to be transcribed to make antisense of RNAi molecules

Antisense RNA technology

a way to block translation of mRNA molecules to silence gene expression

Regenerative medicine

growing cells and tissues that can be used to replace or repair defective tissues or organs

EX: replacing heart and brain cells after a heart attack/stroke, replacing kidneys

tissue engineering

artificial production of tissues and organs in the lab for implantation in the human body

3D bioprinting

is the process of creating cell patterns in a layer-by-layer method to deposit materials known as "bioink" to create tissue-like structures that are later used in medical and tissue engineering fields

Organoids

miniaturized and simplified version of an organ produced in vitro in three dimensions that shows realistic micro-anatomy

Organ-on-a-Chip Model

refers to cells that are cultured on a specialized microchip that attempts to recapitulate the microenvironment of a human organ.

autografting

transplantation of a patient's own tissue from one region of the body to another

EX: coronary artery bypass

Xenotransplation

transfer of organs from different species

Source of embryonic stem cells

inner cell mass of blastocyst

embryonic stem cells

An undifferentiated cell, taken from an embryo that has potential to give rise to various other cell or tissue types, self renewing, pluripotent

stem cell applications

1. Discovery and development of drugs

2. Observing the earliest sign of disease

3. Treatment of disease via implants and transplants

4. Stimulating stem cells in the body via the introduction of reprogramming proteins

therapeutic cloning

The cloning of human cells by nuclear transplantation for therapeutic purposes, such as the generation of embryonic stem cells to treat disease.

reproductive cloning

Using a somatic cell from a multicellular organism to make one or more genetically identical individuals.

ELISA steps

1. Add sample

2. Add primary antibody

3. Add secondary antibody

4. Add substrate (will cause color change if antigen)

5. Look for color change (If no change then there was no antigen)

Phenylthiocarbamide (PTC)

An artificially created substance whose main use is in detecting the ability to taste it; ability to taste PTC is inherited as a dominant.