topics related in this presentation is majorly Cancer, Tumor, Oncogenes, Proto-Oncogenes etc. hope you enjoye and Thumbs up for me.

2. PRESENTED BY: ABDUR RAHMAN KHAN/M-
PHILL
DEPT OF BIOTECHNOLOGY
PRESENTED TO : Dr. MASROOR

3.  Introduction
 Cancer
 Proto Oncogenes
 Discovery of oncogenes
 Oncogenes
 Tumor Suppresser Genes
 Different Genes
 Refrences

4.  Cancer is a group of diseases involving abnormal cell
growth with the potential to invade or spread to other
parts of the body.[2][8] These contrast with benign
tumors, which do not spread to other parts of the
body.[8] Possible signs and symptoms include a lump,
abnormal bleeding, prolonged cough
 While these symptoms may indicate cancer, they may
have other causes.[1] Over 100 types of cancers affect
humans

5.  Normal constituents of cells whose function is to
promote proliferation or cell survival. These genes can
code for growth factors, growth factor receptors, signal
transduction proteins, and transcription factors.
 The proto-oncogene can become an oncogene by a
relatively small modification of its original function.
There are three basic methods of activation

6.  A mutation within a proto-oncogene, or within a
regulatory region (for example the promoter region),
can cause a change in the protein structure, causing an
increase in protein (enzyme) activity.
 An increase in the amount of a certain protein (protein
concentration), caused byan increase of protein
expression (through misregulation)
 A chromosomal translocation (another type
of chromosome abnormality)

8.  Oncogenes produce proteins that have the capacity to
stimulate growth and proliferation. •
 Oncogenes are derived from proto oncogenes which are
genes that encode proteins having function in normal cells
•
 They are dominant or “gain of function” mutations. They
may lead to genetic instability, preventing a cell from
becoming a victim of apoptosis or promote metastasis •
 Different oncogenes become activated in different types of
tumors, which reflects variations in the signaling pathways
that operate in diverse cell types.

9.  First discovered through the ability of Rous sarcoma
virus (RSV) to cause cancer in chickens.
 Mutant studies of RSV: the src gene causes cancer
 “There is a normal cell equivalent of this so-called
“oncogene” and it codes for a protein that has been
associated with tyrosine kinase activity, that
stimulated growth and proliferation via protein
phosphorylation in signal transduction pathways”.

10.  Repression of genes that are essential for
the continuing of the cell cycle.
 Coupling the cell cycle to DNA damage. As long as
there is damaged DNA in the cell, it should not divide.
 If the damage cannot be repaired, the cell should
initiate apoptosis (programmed cell death)
 Some proteins involved in cell adhesion prevent tumor
cells from dispersing, block loss of contact inhibition,
and inhibit metastasis. These proteins are known
as metastasis suppressors.

11.  Caretaker genes:
Maintain the integrity of the genome by repairing DNA damage
 Gatekeeper genes:
Inhibit the proliferation or promote the death of cells with damaged
DNA

13.  Retinoblastoma is a cancerous tumor of the retina. It
occurs in two forms:
 Familial retinoblastoma (hereditary)
 Sporadic retinoblastoma (nonhereditary)
 Mechanism of tumor suppression gene inactivation
 Deletion,DNA methylation, binding viral
oncoproteins , loss of heterogeneity.

14.  Gene encodes a phosphoprotein with 53 kDa with 375 a.a
 It is a transcription factor regulating the cell cycle and
apoptosis.
 It block the cells that have damaged DNA by triggering the
production of another protein P21, which blocks cell
division until the damage is repaired.
 If DNA damage is serve, P53 directs the cell to commit
suicide by apoptosis program
 Most tumors have a complete absence of P53 ,other show
mutation that lead to non function P53
 Inheritance of a mutation in p53 leads to Li-Fraumeni
syndrome.

16.  Wikipedia
(https://en.wikipedia.org/wiki/Oncogene#Proto-
oncogene)
 Slide Share
(https://www.slideshare.net/search/slideshow?searchf
rom=header&q=ONCOGENES)