Samenvatting Cell Biology and Health

Samenvatting Cell biology and
Health
Colleges
- Introduction on PO subjects - Cancer
- Immunology
- Virology
- Toxicology
Practica
- Immunology
- Virology
- Toxicology
PO subjects
- HPV – Immunology
- HPV- Virology
- HPV – Toxicology
- Breast cancer – Immunology
- Breast cancer – Toxicology BPA
- Breast cancer – Toxicology alcohol
- Liver cancer – Immunology
- Liver cancer – Virology
- Liver cancer – Toxicology

College ‘Introduction to PO subjects – Cancer’
Cancer
- 90% environmental disease (including food)
- Number 2 disease of the world
- 1 on 3 persons will be diagnosed with a type of cancer in his/her life
- Main causes: Aging, Obesity and smoking
What is cancer?
- Division: uncontrolled cell division
o More Oncogenes -> Gain of function mutation
o Less function of Tumour suppressor genes (p53) -> blocking the loss of function
mutation
o Less function of Suicide genes (apoptosis) -> no apoptosis when cells are wrong
o Less function of DNA repair genes -> poor repair of cell damage
- Growth: formation of a lump (tumour) or large numbers of abnormal cells in the blood
(neoplasia)
o Pressure on nerves
o Blocking organs
o Stopping normal function

, o Altering nerve
signals
o fungating
- Mutation: changes to
how the cell is viewed by
the immune system
- Spread: ability to move
within the body and
survive in another part +
angiogenesis (new
blood vessels)
- Malignant as opposed to
benign:
o Malignant: rapid
growth, invasive,
potential for
metastasis
 When melanoma (initial
tumor) cells enter
bloodstream: danger!
o Benign: slow
growth, non-
invasive, no
metastasis
- Types of cancer:
o Carcinomas (lung, breast, colon, prostate etc.)
o Sarcomas (fat, bone, muscle)
o Lymphomas (lymph system)
o Leukaemias (blookstream)
o Adenomas (Glandular benign tumor)
- Is cancer heritable?
o There are some heritable cancer syndromes
o Majority not familial
o 5-8% is genetically determined
- What causes the mutations which lead to cancer?
o Viruses: HPV -> cervical cancer
o Bacteria: H. pylori -> Gastic cancer
o Chemicals: B[a]P -> Lung cancer
o UV and ionizing radiation -> skin cancer
- How does these things work?
o Viruses: insertional mutagenesis
o Chemicals: DNA adducts
o UV: single and double strand DNA breaks
- What types of genes get mutated in cancer?
o Oncogenes are activated -> over active cell growth
 Their normal function is: giving signal for cell growth, gene transcription
o Tumor suppressor genes are inactivated -> Less DNA repair, cell cycle control
etc.
- Chromosome translocation
o Example: chromosome number 8 & 14: they transfer certain parts of their
chromosome -> creating proteins that give signals to the body -> fooling the
body to produce more cells -> extreme cell division of that cell -> tumour cells!
o Example 2: chromosome number 9 & 22: exchange of parts of their chromosome
(ABL goes from CH 9 to the BCR part of CH 22) -> Philadelphia chromosome (Ph1
chromosome) -> Kinase activity -> Activation of proteins -> see example 1
- Growth factor receptors
o Tumour expresses gene for a growth factor (EGF, epidermal growth factor) -> the
receptor gene for the EGF is induced by overexpression of the protein HER2

, (Human epidermal growth factor receptor - 2) -> Her2 is very typical in many
types of tumors! (breast cancer!)
o Treatment for this breast cancer: Herceptin! -> antibody that blocks the receptor
induced by HER2 protein overexpression -> EGF can’t bind anymore -> No signal
for the cell to divide and to grow
- Marker genes
o Fetal/embryonic genes: switcht on during growth in the uterus and switcht off
after -> will be never switched on again! -> When found in the blood, tissue or
something: it marks for a tumour! (not 100% of the cases..)
- The six hallmarks of cancer:
o Self-sufficient growth signals
 Constitutively activated growth factor signalling
o Resistance to anti-growth signals
 Inactivated cell cycle checkpoint
o Immortality
 Inactivated cell death pathway
o Resistance to cell death
 Activated anti-cell death signalling
o Sustained angiogenesis
 Activated VEGF signalling
o Invasion and metastasis
 Loos of cell-to-cell interactions -> it has no boundary’s, like when there is
normal cell growth



Colleges Immunology
Deel 1: (Colleges 1-4)
Introduction to the immune system
The main functions of the immune
system:
- Protection against infectious
microbes, ‘non-self’
o Intracellular: viruses
and some bacteria and
parasites
- Protection against modified
‘self’
o Cancer/tumour cells or
transformed cells
o Auto-immune
reactivity




Figure - Many different immune cells differentiated from the
stem cell