INTRODUCTION HISTORY GENES INVOLVED IN CANCER ONCOGENES TUMOUR SUPPRESSOR GENES ONCOGENE INTRODUCTION TYPES ACTIVATION OF PROTO ONCOGENES FUNCTION TUMOUR SUPPRESSOR GENES INTRODUCTION EXAMPLE RB GENE TP53 GENE CONCLUSION REFERENCES

1. CANCER GENETICS
By
KAUSHAL KUMAR SAHU
Assistant Professor (Ad Hoc)
Department of Biotechnology
Govt. Digvijay Autonomous P. G. College
Raj-Nandgaon ( C. G. )

2. SYNOPSIS
INTRODUCTION
HISTORY
GENES INVOLVED IN CANCER
• ONCOGENES
• TUMOUR SUPPRESSOR GENES
ONCOGENE
• INTRODUCTION
• TYPES
• ACTIVATION OF PROTO
ONCOGENES
• FUNCTION

3. TUMOUR SUPPRESSOR GENES
•INTRODUCTION
•EXAMPLE
• RB GENE
• TP53 GENE
CONCLUSION
REFERENCES

4. INTRODUCTION
CANCER
• Cancer is a group of disease that
involve uncontrolled division of
cells.
• It is due to failure of the
mechanism that usually control the
growth and proliferation of cells.

5. • Cancer arises from a single cell which has
undergone mutation.
• TUMOUR is a cluster of cells resulting
from rapid cell growth
• Cancer genetics deals with the study of
genes involve in causing cancer.
• Most or all cause of cancer are genetic
damage.

6. HISTORY
• 1890- HANSEMANN -abnormal
behaviour of chromosome in cancer
cell.
• 1911- PEYTON ROUS -a virus can
cause cancer when injected into a
suitable host animal
• 1976- Dr.J.MICHAEL BISHOP and
HAROLD E. VARMUS oncogenes
were defective proto-oncogenes.

7. GENES INVOLVED IN CANCER
ONCO GENES
TUMOUR SUPRRESSOR GENES

8. 1) ONCOGENES
• The word ONCO comes from a Greek word
onkos –bulk or mass
• Any gene that encodes a protein able to
transform cells in culture or to induce
cancer in animal.
• Oncogene encode protein that promote the
loss of growth control and conversion of a
cell to a malignant state.

9. TYPES
Cellular or c-oncogene -present in host
cell and carry out all the necessary
function of the host cell.
• Viral or v-oncogene- derived by capturing
a proto-oncogene from a host genome.

10. ACTIVATION OF
PROTO-ONCOGENES TO
ONCOGENES
• .

11. Mechanism of
activation
•
I. MUTATION
II.GENE
DUPLICATION
III.CHROMOSOME
REARRANGEME
NT

12. Fig;-mutation in oncogene

13. Fig;-Types of protein encoded by oncogene.
FUNCTION

14. 1.Oncogenes That Encode Growth
Factors
• Cancer-causing simian sarcoma virus
contained an oncogene (sis) derived from
the cellular gene for platelet-derived
growth factor (PDGF), a protein present in
human blood.
• Cultured cells that are transformed with
this virus secrete large amounts of PDGF
into the medium, which causes the cells to
proliferate in an uncontrolled fashion.

15. 2. Oncogenes That Encode Growth Factors
Receptors(GFR)
• Malignant cells contain a much larger
number of the receptors which makes the cells
sensitive to much lower concentrations of the
growth factor.
•Proto-oncogene encode GFR can also activated
by mutation that cause the receptor monomer
to undergo dimerization in the absence of
exogenous ligand, which leads to their protein
kinase activity.

16. 3.Oncogenes That Encode Cytoplasmic
Protein Kinases

17. 4.Oncogenes That Encode Nuclear
Transcription Factors
•Cells that are not actively
growing and dividing tend to
withdraw from the cell cycle and
enter to G0,stage.
Myc is one of the first proteins to
appear when a cell in this quiescent stage
has been stimulated by
growth factors to renters the cell cycle
and divide.

18. 5.Oncogenes That Encode Products That
Affect Apoptosis

19. 2) TUMOUR SUPPRESSOR GENES
(TSG)
TSG inhibit cell proliferation by
arresting progression through the cell
cycle.
Protein encoded by TSG act as
negative regulation of cell proliferation.
Their elimination promotes
uncontrolled cell growth

20. Fig;-Mutation in TSG

22. EXAMPLE
1) RB GENE
This gene responsible for
RETINOBLASTOMA cancer of
retina of eye..
-

23. • Retinoblastoma
is inherited.
• Retinoblastoma
requires both
copies of the RB
gene either
mutated or
eliminated.
1)SPORADIC
2)FAMILIAL

24. Fig:- pRB in
controlling
transcription
of genes
required for
progression of
the cell cycle.

25. 2) TP53 GENE
• TP53 is a TSG that when absent is
responsible for a rare disorder called
Li-Fraumeni syndrome.
• Inherit one normal and one abnormal
(or deleted) allele of the TP53
tumour-suppressor gene.
Function of p53
p53 is a transcription factor that
activates the expression of genes
involved in cell cycle regulation and
apoptosis.

26. Fig;-Function of p53

27. •The Role of p53:
•p53 is a transcription factor that activates
the expression of either-
•p21 gene, whose product cause cell arrest
or,
Bax gene, whose product cause apoptosis .
•genetic damage, as occurs if the cell is
subjected to ultraviolet light or chemical
carcinogens, the concentration of p53 rises
rapidly.
•p53 degradation is facilitated by a protein
called MDM2.

28. fig;-Role of p53 in regulation of cell cycle

30. S.
No.
BOOKS AUTHOR
1. Cell and molecular
biology
Gerald karp
2. Molecular cell biology Lodish
3. Molecular biology of
cancer
F. Macdonald and
C.H.J. Ford
4. Internet www.kbiotech.com
5. Internet www.genetics.edu.au
References