Test 3 Gene therapy, antisense therapy and related technologies

Question 1

gene therapy

Answer 1

introduction of corrective genes into cells of pt

Question 2

in vitro (ex vivo) gene therapy

Answer 2

take cells out of body and modify them outside of the body and return them to the pt

Question 3

in vivo gene therapy

Answer 3

gene therapy directly administered to pt

Question 4

non viral vectors

Answer 4

uses chemical or mechanical manipulation to introduce genes into cells

Question 5

example of non viral vectors

Answer 5

• DNA coated on gold particles which is then blasted into target tissue
• DNA encapsulated inside artificial liposome which then fuses into pt’s cell membranes
• DNA attached to ligands that can bind to specific receptors on target cells
• ectroporation to facilitate movement of DNA into cell

Question 6

viral vectors

Answer 6

modified virus genome used to remove genes that causes disease and/or allow incorporation of new genes for therapeutic purposes

Question 7

examples of viral vectors

Answer 7

• adenovirus
• herpesvirus
• retrovirus

Question 8

retrovirus

Answer 8

• inject RNA into cell
• integrase: integrates viral DNA into human genome; not gene specific
• virus is released after the cell dies
• create packaging strains

Question 9

adenovirus

Answer 9

• has much bigger genome than retrovirus

- replace viral gene with gene of interest

Question 10

transductional targeting

Answer 10

virus infects only a specific cell type

Question 11

transcriptional targeting

Answer 11

virus replicates only in a specific type of cell

Question 12

Kymriah

Answer 12

• treats Acute lymphoblastic leukemia
• modified virus introduces chimeric antigen receptor T cell
• causes T cell to express new antigen on receptor
• identifies and removed CD19 expressing malicious cells (B cell marker)

Question 13

T-VEC (Talimogene laherparepvec)

Answer 13

• Engineered herpesvirus
• can only replicate in tumor cells
• immunomodulatory gene therapy: if replicates in normal cell, nothing happens; replicate in tumor cells and also produce GM-CSF to attract dendritic cells to the site which stimulates T cells

Question 14

herpes virus

Answer 14

• acyclovir only attacks in the presence of thymidine kinase
• introduce thymidine kinase into DNA of tumor and use acyclovir to kill it off

Question 15

Antisense Therapy

Answer 15

• introducing an antisense oligonucleotide to the infected or cancerous cell to block transcription or destroy the mRNA
• creates double stranded RNA which triggers production of RNase H which comes and cuts the site and inactivates the mRNA

Question 16

Formivirsen (Vitravene)

Answer 16

• sulfur di-ester bond an antisense therapy

- inhibits cytomegalovirus (CMV)

Question 17

RNAi

Answer 17

• Uses double-stranded RNA to induce gene specific silencing via by a highly conserved family of RNases
• activates an enzyme-like activity that can destroy multiple target mRNA molecules

Question 18

CRISPR-Cas9

Answer 18

• plasmid introduced into cell which contains Cas9 and Guide RNA
• Guide RNA cuts genome DNA
• can lead to edited or disrupted gene

Question 19

Macugen (Pegaptanib)

Answer 19

• aptamer

- used to treat age related macular degeneration