TARGETED GENE THERAPHY

1. TARGETED GENE
THERAPY
DR.S.SELVA MANI
II YEAR POST GRADUATE
DEPT.OF.PUBLIC HEALTH DENTISTRY

2. CONTENTS
• Introduction
• Gene therapy
• Historical background
• Types of gene therapy
• Steps in gene therapy
• Various Vector agents
• Route of administration
• Cancer –gene theraphy
• Hallmarks of tumor
• Conclusion

3. INTRODUCTION

4. GENE THERAPY ?

5. HISTORY
Ashanti DeSilva JesseGelsinger

7. TYPES
1. GERM LINE THERAPY
2. SOMATIC GENE THERAPY
• EX –VIVO GENE THERAPY
• IN -VIVO GENE THERAPY

8. EX-VIVO GENE
THERPHAY

9. EX-VIVO GENE
THERPHAY

11. IN –VIVO GENE THERPHAY

12. IN –VIVO GENE
THERPHAY

13. IN –VIVO GENE
THERPHAY

14. STEPS IN GENE THERAPY
Identification of affected gene
Cloning of healthy gene
Loading vector with
therapeutic gene
Vector reaches target cell
Delivering therapeutic gene
into nucleus of target cell
Genetic material intergrated
into DNA and performs

16. METHODS
• In vivo approach- Inject the vector into the body and
specifically target affected cells.
• Ex vivo approach- Isolating the desired cells from the body.
Culturing the cells in a Petri dish in the laboratory.

18. IDEAL CHARACATERISTICS
OF VECTOR
VARIOUS TYPES OF VECTOR

20. MICROMANIPULATOR.

33. ROUTE OF ADMINISTRATION

35. Immuno-gene therapychemoprotection
suicide gene therapy
tumor suppressor
(p53)

36. Cancer gene therapy
1.Direct attack on tumor cells
a)transfer of tumor suppressor gene
b)inhibition of oncogenes
c)suicide genes
d)oncolytic viruses (replication-competent
viruses)
2.Harnessing immune response to tumor antigens
3.Chemoprotection
4.Anti-angiogenic therapy

37. p53 – the guardian of the genome

38. p53-induced cell-cycle arrest in response to DNA damage.
The normally unstable p53 protein is stabilized by damaged DNA, so its
concentration increases. Acting as a transcription factor, p53 induces expression of
p21CIP, a cyclin-kinase inhibitor that inhibits all Cdk1-, Cdk2-, Cdk4-, and Cdk6-
cyclin complexes. Binding of p21CIP to these Cdk-cyclin complexes leads to cell
cycle arrest in G1 and G2

39. First officially registered therapeutic nucleic acid
Gendicine (SiBiono GeneTech, Chiny)
Adenoviral vector with a correct p53 gene
Efficient in patients with head and neck cancers
Appears 3 x more efficient than radiotherapy alone
Registered on 16. X. 2003, after 5 years of clinical trials

40. Advexin – adenoviral vector expressing p53 gene
effective in patients with head and neck cancer

41. Nature Biotechnology, January 2004
Examples of the most advanced clinical trials of
cancer gene therapy

42. Suicide gene therapy –pro-drug activation
The objective of pro-
drug activation
therapy is to express
an activating enzyme
within the tumor,
which will then
activate a
systemically
delivered, inactive
pro-drug
at the target site only

43. Enzyme-prodrug combination for suicide gene
therapy
Enzyme Prodrug Product Mechanism
HSV-tk ganciclovir ganciclovir triphosphate blocks DNAsynthesis
cytosine deaminase 5-fluorocytosine 5-fluorouracil (5-FU) blocks DNA and RNA
synthesis (pyrimidine antagoni
cytochrome P450 cyclophosphamide phosphoramide mustard DNA alkylating agent;
blocks DNAsynthesis

44. Strategy of genetically modified tumor vaccines
• Isolate tumor cells from a
patient
• Alternative – culture other
tumor cells- eg, cell line of
the same type – i.e. allogeneic
cell line
• Transduce such cells with
vector – eg. Retroviral vector
harboring cytokine gene
• Inject such modified cells into
patients
• Antigens present on
allogeneic tumor cells
stimulate immune system,
which respond to the same
antigens present on patient’s
tumor
• Cytokines enhance the
response

45. IL-6 and sIL-6R retrovirus melanoma (allogeneic)
A. Mackiewicz et al., - Poznań
Wadhwa et al., Ann Rev Med. 2002

46. Physiological angiogenesis in adults is
restricte
placent
a
uterus
Hair growth
Wound healing

47. In healthy organism the action of activators
and inhibitors of angiogenesis is balanced
Nature Review Cancer

48. Strategies of anti-angiogenic gene therapy

49. Drawbacks of anti-cancer gene therapy
1. Limited access to tumor cells
2. Heterogeneity of tumor cells
3. Emergency of resistant tumor cells
4. Toxicity
Advantages of anti-angiogenic gene therapy
1. Little or no toxicity
2. Does not require that therapeutic agent enter any tumor cells nor cross the
blood brain barrier
3. Acts independently of tumor cell heterogeneity and tumor type
4. Does not induce acquired drug resistance

50. •Recent update
•KIF11 as a novel prognostic biomarker and therapeutic target for
oral cancer-protein required for establishing a bipolar spindle in cell
division(kayo et al.,Oct 2017)
•To date, almost 2600 gene therapy clinical trials have been
completed, are ongoing or have been approved worldwide.(The
Journal of Gene Medicine)
•Chimeric antigen receptors (CAR Tcells) represent another
autologous cell‐based therapy targeting tumour‐associated
cell‐surface antigens that had entered the clinic.
•Latest news on gene therapy – found successful trails in treament of
beta-thalassemia

52. In vivo approved gene therapy drugs such as Neovasculgen, Glybera, Defitelio, Rexin-G,
Onpattro, Eteplirsen, Spinraza,, Vitravene as well as Zolgensma directly injected into their
target tissue or organ.

56. . Gene Therapy Market 2015-2025, Roots Analysis Report (2017).

59. CONCLUSION
• In future, this technique will be an everyday used
word and change the field of medicine and the
potential of treatment is limitless
• Studies states that increasing percentage of Oral
cancer which be higher rates by 2020 and 2030
• The development of gene therapy will be definite cure
though have an increasing rate of incidence

60. REFERENCES
Dubey R.C, A textbook of biotechnology, 1st
edition(2004), S Chand and company, New Delhi
Gupta P.K, Elements of Biotechnology, 1st
edition(2001), Rastogi Publications, Meerut.
Satyanarayana U, Biotechnology, 1st edition, Book and
allied (P) Ltd, Kolkata.
http://www.medindia.net/articles/genetherapy_treat
ment.htm
http://en.wikipedia.org/wiki/Gene_therapy