Cancer signaling pathway

1. Cancer Signaling pathway
Prepared by:
Osaid Al Meanazel
Ph.D. student, King Saud University, Saudi Arabia

2. Contents:
• Cancer: Introduction
• Signal Transduction in Cancer
• References

3. Introduction
• Cancer:
• The division of normal cells is precisely controlled. New cells are only formed for
growth or to replace dead ones.
• Cancerous cells divide repeatedly out of control even though they are not
needed, they crowd out other normal cells and function abnormally. They can
also destroy the correct functioning of major organs.
• Cancer arises from the mutation of a normal gene.
• Mutated genes that cause cancer are called oncogenes.
• It is thought that several mutations need to occur to give rise to cancer
• Cells that are old or not functioning properly normally self destruct and are
replaced by new cells.
• However, cancerous cells do not self destruct and continue to divide rapidly
producing millions of new cancerous cells.

4. • A factor which brings about a mutation is called a mutagen.
• A mutagen is mutagenic.
• Any agent that causes cancer is called a carcinogen and is described as
carcinogenic.
• So some mutagens are carcinogenic.
• Examples on carcinogens:
Ionising radiation – X Rays, UV light
Chemicals – tar from cigarettes
Virus infection – papilloma virus can be responsible for cervical cancer.
Hereditary predisposition – Some families are more susceptible to getting certain
cancers. Remember you can’t inherit cancer its just that you maybe more
susceptible to getting it.

5. • Benign tumours do not spread from their site of origin, but can crowd
out (squash) surrounding cells eg brain tumour, warts.
• Malignant tumours can spread from the original site and cause
secondary tumours. This is called metastasis. They interfere with
neighbouring cells and can block blood vessels, the gut, glands, lungs
etc.

6. Signal Transduction in Cancer
• Signal Transduction is the process
where the cell is convert an
extracellular signal into response.
• Involved in: Cell-cell
communication, Cell’s response
to environment, and Intracellular
homeostatsis- internal
communication.

7. • Components of Signalling:
Peptides / Proteins- Growth Factors
Amino acid derivatives - epinephrine, histamine
Other small biomolecules – ATP
Steroids, prostaglandins
Gases - Nitric Oxide (NO)
Photons
Damaged DNA
Odorants, tastants
• Signal = LIGAND
Ligand- A molecule that binds to a specific site on another molecule, usually a protein, ie
receptor.

8. • What are
Receptors?
 Sensors, what the
signal/ligand binds
to initiate ST.

9. • Cell Surface receptors type:
1. Ligand-gated ion channel
2. G-protein coupled receptor
3. Enzyme linked receptors; ie Growth Factor receptors.

10. • Growth Factors
Ligands which bind enzyme
linked receptors Signal
diverse cellular responses
including: Proliferation,
Differentiation, Growth,
Survival, and Angiogenesis
 Can signal to multiple cell
types or be specific

12. • Most growth
factors binds
to Tyrosine
Kinases

16. Pharmaceutical Approached in the treatment
of Cancer
• https://www.youtube.com/watch?v=zE4BkAw_lL4

17. References
• http://www.cell.com/cancer-cell/pdf/S1535-6108(03)00216-2.pdf
• http://basicmedicalkey.com/wp-
content/uploads/2017/02/image02545.gif
• https://www.spandidos-
publications.com/article_images/ijmm/38/1/IJMM-38-01-0003-
g00.jpg