Transcript Genomics and Me

Genomics and Me
The Study of Cancer Disease
Introduction
What is Cancer Disease?
 A set of disease in which cells escape from the
control mechanisms
 Will cause death
 Cancer gene products produced in two ways
Quantitatively
- gene products expressed at an abnormally
level or not expressed at all.
Qualitatively
- DNA sequence changed (gene is mutated)
How to detect the cancer gene?
By comparing the “fingerprint” of a normal cell
with a cancer cell will highlight genes by their
suspicious presence or absence, the cancer
genome anatomist can determine whether such
suspect play a role in cancer.
Cancerous cell usually undergo a gradual
transformation and often goes undetected for
years. Thus the cancer cell genetic study is very
important in cancer curing.
Causes of Cancer

Chemicals
- Chemical in the workplace
e.g. manufacture of dyes and chemicals
- Tobacco and Alcohol
- Diet
aromatic amines and polycyclic hydrocarbons
(over cooking)
free radicals (metabolism of certain food)
- Environmental pollution
-aromatic hydrocarbons produced by the burning of
of wood, tobacco, and fossil fuels
Viruses
e.g. hepatitis B virus (HBV) and the human
immunodeficiency virus (HIV)
 Irradiation
Ultraviolet from sunlight and
atomic/ionizing radiation such as nuclear
explosions

Not all carcinogens do cause cancer because
 most are eliminated by the immune system.
 one mutation usually is not enough to cause
cancer
How cancer causes?
There is a cellular gene called protooncogene, which code for proteins that stimulate
normal cell growth and division. When protooncogene turns to oncogene , cancer will occur.
When proto-oncogene exposed to
carcinogen (cancer-causers), its fragile sites will
break and then proto-oncogene will turn to
oncogene.
The genetic changes that convert protooncogene to oncogene fall into three main
categories
 movement of DNA within the genome
 amplification of a proto-oncogene
 point mutation in a proto-oncogene
Treatment Methods of Cancer
Gene therapy
 a new technique of cancer treatment
 to treat cancer patients by alter patient’s
genetic material to fight or prevent cancer
 improve human body’s natural ability to
fight the disease or make the cancer cells
more sensitive to other kinds of therapy
Methods
 supply cells with healthy copies of missing
e.g. insert missing DNA into a certain genetic
material by vectors
 altered gene by insert missing DNA or change
cell’s function
e.g. stimulate immune system cells to attack
cancer cells, and to introduce the multidrug
resistance (MDR) gene into stem cells
 the most common vectors are viruses.
Retroviruses are usually used
ex vivo
To remove patients’ cells and grown the cells in
the laboratory . Exposed to cells to the virus that
is carrying the desired gene. The virus will enter
the cell, and the desired gene will become the
part of cells’ DNA. Finally inject the cells into
patients’ vein.
 in vivo
the desired gene is delivering to the patients’
cells by vectors or liposomes inside the patients’
body.

The Side effects
 when viral vectors carry desired gene into
cells, they might altered genes of other
healthy cells
 the new gene might be inserted into the
wrong location in DNA
 the transferred gene may be over
expressed that produce too much of
missing protein and may cause
inflammation, and then the virus could be
transmitted from the patients to other
people
The first disease approved for treatment
with gene therapy was adenosine
deaminase (ADA) deficiency.
The first clinical trial of gene therapy began
in September 1990
Surgery
 Cryosurgery
the use of extreme cold to destroy cancer
side effects : can lead to heavy bleeding
 Laser therapy
- carbon dioxide (CO2) laser
- neodymium:yttrium-aluminum-garnet
(Nd: YAG) laser
- argon laser
Chemotherapy
The using of “antidrugs”.
side effects : also harm to healthy cell
Radiation therapy
Also called radiotherapy, is the treatment of
cancer with ionizing radiation.
usually used involves photons, such as X-ray
And Gamma rays.
Side effects: temporary or permanent loss of hair,
the skin irritation in the treated area.
Biological therapy
Sometimes called immunotherapy, is a
therapy that use the body immune system
to fight cancer or to lessen the side effects
which caused by other cancer treatment.
It is to repair, stimulate, or enhance the
immune system’s responses by using of
antibodies, cytokines, and other immune
substances.
The End
Have a nice Christmas 