View
214
Download
0
Category
Tags:
Preview:
Citation preview
In The Name Of God
Targeting Gene Therapy Targeting Gene Therapy to Cancerto Cancer
Abstract
In recent years the idea of using gene therapy specially,cancer gene therapy will need to combine highly selective gene delivery with highly specific gene expression,specific gene product activity and specific drug activation.
This presentation will discuss the progress has made in recent years about the efficient delivery of DNA to tumour sites.
IntroductionIntroduction
MAJOR MAJOR DEVELOPMENT IN DEVELOPMENT IN GENE THERAPYGENE THERAPY
19891989::THE FIRST PROTOCOL FOR THE FIRST PROTOCOL FOR CANCER GENE THERAPYCANCER GENE THERAPY
19901990::GENE THERAPY TO TREAT SCID GENE THERAPY TO TREAT SCID USING STEM CELLSUSING STEM CELLS
19931993::NEW GENE THERAPY APPROACH NEW GENE THERAPY APPROACH REPAIRS ERRORS IN mRNAREPAIRS ERRORS IN mRNA
New approach using liposome 25 New approach using liposome 25 nanometersnanometers
SICKLE CELL DISEASE IS A SUCCESSFULLY TREATED IN MICE
2003:USING LIPOSOME COATED WITH PEG TO TREAT PARKINSON DISEASE
USING siRNAs TO TREAT HUNTINGTON
2006:THE FIRST REPORT THAT GENE THERAPY CAN BE EFFECTIVE IN TREATING CANCER
PREVENTION THE IMMUNE SYSTEM WITHMicro RNA
2007:THE FIRST GENE THERAPY TRIAL FOR INHERITED RETINAL DISEASE
2008:TREATMENT OF LEBER CONGENITAL DISEASE
TYPE OF GENE THERAPY
SOMATIC CELL GENE THERAPY
GERM LINE GENE THERAPY
GENE THERAPY
***REMOVE GENE FROM A SELECTED TISSUE
***EXPOSITION TO THE GENE TRANFER VECTOR
***SELECTION FOR TRANSGENIC USING MARKER
***REINTRODUCTION THE CORRECTED IN TO THE PATIENT BODY
GENE THERAPYGENE THERAPY
INJECTION THE VECTOR DIRECTLY INJECTION THE VECTOR DIRECTLY IN TO THE TARGETED TISSUEIN TO THE TARGETED TISSUE
BROAD METHODSBROAD METHODS
******REPLACE A NON FUNCTIONAL GENEREPLACE A NON FUNCTIONAL GENE
******HOMOLOGOUS RECOMBINATIONHOMOLOGOUS RECOMBINATION
******SELECTIVE REVERSE MUTATIONSELECTIVE REVERSE MUTATION
******THE ALTERATION OF THE GENE THE ALTERATION OF THE GENE REGULATIONREGULATION
To increase specificity and safety of gene therapy needs to:
Gene delivery using viral and non-viral method.
Targeting gene expression
Condition targeted expression
Disease targeted expression
Targeted delivery
Molecular
chemotherapy
Genetic
immunopotentiationMutation
compensation
Delivery of suicide gene
Gene directed enzymeProdrug therapy
Viral and
non-viral
.1methods
Viral-mediated
methods
Lipid-mediated
methods
The
others
retrovirus HVJAdeno
virusLiposome
Micro
injection
Microparticle
bombardment
LIPOLEXES
ANIONIC NEUTRAL CATIONIC
POLYLEXES
CHITOSANTRIMETHL CHITOSAN
HYBRID METHODSHYBRID METHODS
VIROSOMESVIROSOMES((LIPOSOME +INACTIVATED HIVLIPOSOME +INACTIVATED HIV))
DENDRIMERS
Non solid tumoursNon solid tumours::
Herpes simplex virus thymidine Herpes simplex virus thymidine kinase and cytosine deaminasekinase and cytosine deaminase
Modified envelope proteinsModified envelope proteins
Targeted delivery of DNA via Targeted delivery of DNA via receptorreceptor
Solid tumoursSolid tumours::An aerobic bacteriaAn aerobic bacteria
Retroviral vectors with modified envelope proteins
Mo-MuLV
SU TM
Binding ofthe virus to
Its cell receptor
Anchors the molecule to
the viral membrane
SPECIFIC TARGETING STRATEGIES OF CANCER
GENE THERAPY USING scFv
•RETROVIRAL VECTOR DISPLAYS BOTH ANTI CEA scFv AND Inos gene
•CHIMARIC RECEPTOR GENE WHICH ENCODED AN NATI CEA scFv AND THE ZETA CHAIN OF TCR/CD3
Delivery of suicide geneDelivery of suicide gene
Targeted delivery of Targeted delivery of DNA via receptorDNA via receptor
•REDIRECTING VIRUS TO A TISSUE REDIRECTING VIRUS TO A TISSUE SPECIFIC RECEPTORSPECIFIC RECEPTOR
•USING TISSUE SPECIFIC LIGANDS OR USING TISSUE SPECIFIC LIGANDS OR mAb INCORPORATED ON TO THE mAb INCORPORATED ON TO THE SURFACE OF LIPOSOME TO DIRECT SURFACE OF LIPOSOME TO DIRECT THEM TO TARGET CELLSTHEM TO TARGET CELLS
Targeted delivery and receptor overexpressing human cells
EGF-R
Folate-R
C-kit-R
VDEPTVDEPT
Virally directed enzyme Virally directed enzyme prodrug therapyprodrug therapy
SYNTHETIC OLIGONUCLEOTIDES
ANTISENSE siRNA
DOUBLE STRANDED OLIGODEOXYNUCLEOTIDES
PEPTIDE NUCLEIC ACID SEQUENCE SPECIFIC
RECOGNITION IN TARGETING GENE THERAPY TO CANCER
PNA IN CANCER GENE THERAPY
•***INHIBITION OF TELOMERASE ACTIVITY
•***ANTISENSE AND ANTIGENE ACTIVITY OF PNA TO HUMAN B-CELL LYNPHOMA
•***INHIBITION OF HIV REVERSE TRANSCRIPTASE
•***PNA AS A GENETIC ANTIBIOTICS
•***DIHYDROTESTOSTRONE LINKED TO PNA AS A VECTOR FOR TARGETING C-MYC DNA TO PROSTATIC CANCER CELLS
EFFECTIVE METHODS TO EFFECTIVE METHODS TO INDUCE UPTAKE OF PNA IN TO INDUCE UPTAKE OF PNA IN TO CELLSCELLS
******ELECTROPORATIONELECTROPORATION
******CATIONIC LIPIDSCATIONIC LIPIDS
******ADENO VIRUS-POLYLYSINE ADENO VIRUS-POLYLYSINE COMPLEXESCOMPLEXES
******STEREPTOLYSINESTEREPTOLYSINE
TRANSCRIPTIONAL CONTROL OF EXPRESSION
T0MOUR SPECIFIC PROMOTERST0MOUR SPECIFIC PROMOTERS
11))PROMOTERS THAT SPECIFIC ONLY PROMOTERS THAT SPECIFIC ONLY IN MALIGNANT PROCESSIN MALIGNANT PROCESS
22))PROMOTERS THAT ONCOFOETAL PROMOTERS THAT ONCOFOETAL RELATED WITH TISSUE SPECIFICITYRELATED WITH TISSUE SPECIFICITY..
33))TOMOUR MICROENVIROMENT-TOMOUR MICROENVIROMENT-RELATED PROMOTERSRELATED PROMOTERS
44))TOMOUR VASCULATURE-RELATED TOMOUR VASCULATURE-RELATED PROMOTERSPROMOTERS..
Tissue targeted expression
Alpha feto protein to Alpha feto protein to target hepatocellular target hepatocellular
carcinomacarcinoma
AFP has been found to be abnormally activated in hepatocellular carcinoma.
Transgenic mice carrying the SV40 large T-antigen developed carcinoma crossed with mice transgenic for HSV thymidine kinase.
HSVtk activate GCV under the AFP promoter/enhancer control.
•Tissue targeted expressionTissue targeted expression•Albumin enhancer to target liver Albumin enhancer to target liver
cancercancer
Retroviral vector containing the liver-specific expression system.
The albumin enhancer element and promoter to target expression of B-gal to hepatoma cells.
Expression could only be detected in dividing hepatocytes.
Condition targeted expression
Tissue-type plasminogen activator regulated Tissue-type plasminogen activator regulated by radiationby radiation..
t-pA induces over 50 fold after irradiation t-pA induces over 50 fold after irradiation with x-rayswith x-rays..
The t-pA protease have a function The t-pA protease have a function equivalent to the sos repair systemequivalent to the sos repair system..
GRP encoding gene was used to control expression of a marker gene in a murine fibrosarcoma model.
In vitro glucose deprivation of transduced fibrosarcoma cells showed an 8-fold induction over non-stressed cells.
Hypoxia regulated gene expressionHypoxia regulated gene expression)in almost solid tumours()in almost solid tumours(
Hypoxic conditions can modulate Hypoxic conditions can modulate the expression of a number genesthe expression of a number genes::
Encoding growth factorsEncoding growth factors..
Transcription factorsTranscription factors..
Glycolytic and DNA repair enzymesGlycolytic and DNA repair enzymes..
Hypoxic expression is controlled by the Hypoxic expression is controlled by the binding of transcription factor(HIF-1) to a binding of transcription factor(HIF-1) to a DNA sequence which can be enhancer or DNA sequence which can be enhancer or response element.(HRE)response element.(HRE)
The use of hypoxia enhancer elements increase the levels of the marker gene CD2.
Hypoxic induction in vivo of the CD2 was confirmed by CD2 staining with the comet assay.
In comet assay,tumour cells are treated with radiation and a bioreductive drug)which indices DNA crosslinks only in hypoxic cells(
Electrophoresis of single cells isolated from the treated tumours can differentiate the two populations.
The hypoxic cells,according to the comet The hypoxic cells,according to the comet assay,stained positive for CD2,whereas the assay,stained positive for CD2,whereas the aerobic ones did notaerobic ones did not..
This result demonstrate the selectivity of the This result demonstrate the selectivity of the system and its potential for tumour specific system and its potential for tumour specific targeting of gene expressiontargeting of gene expression..
INDUCTION OF APOPTOSIS IN INDUCTION OF APOPTOSIS IN HYPOXIC CONDITIONHYPOXIC CONDITION
P53P53
BAXBAX
hREC2hREC2
Caspase-8Caspase-8
Genetically modified tomour vaccines in gene therapy
Cytokine genes
Co-stimulatory moleculesCo-stimulatory molecules
DNA VACCINE
ConclusionConclusion
Gene therapy has the potential to have few side effects and lower systemic toxicity than current therapies.
Also choosing only one criteria for selectivity such as targeting delivery to cells or tissue specific expression,is not sufficient.
Only by combining the Only by combining the most successful strategies most successful strategies in cancer gene therapy in cancer gene therapy approaches,will be a approaches,will be a successful clinical successful clinical treatment emergetreatment emerge..
Recommended