Biology of Cancer Flashcards
(51 cards)
Define Cancer
a group of diseases characterised by unregulated cell growth followed by the invasion and spread of cells from the site of origin to other sites in the body.
What % of Cancers arise in Epithelial Cells? Why
85%
it is a site of constant proliferation
What is a Cancer of Epithelial Origin Called?
Carcinoma
What is a Cancer of Mesodermal Tissues Called?
Sarcomas
What is a Cancer of Glandular Tissues Called?
Adenocarcinomas
Define Senescent
cell no longer replicates
At what point do Cells become Senescent
- at the end of each chromosome = telomere
a telomere is a repeated sequence of DNA - telomere shortens with every round of replication
- cell stops dividing when telomere reaches a certain length
What are the 6 Hallmarks of Cancer? Add 2 Extra Hallmarks
- Sustaining Proliferative Signalling
- Evading Growth Suppressors
- Activate Invasion and Metasis
- Enabling Replicative Immortality
- Induing Angiogenesis
- Resisting Cell Death
- Deregulating Cellular Energetics
- Avoiding Immune Destruction
Give 2 Enabling Characterstics of Cancer which Enhances the Hallmarks
- Genome Instability and Mutation
- by causing dna to be faulty, it causes genome instability, passes down onto daughter cells - Tumour Promoting Inflammation
- all malignant cells contain inflammatory cells
- can release reactive species, growth factors and enzymes
Give 6 Environmental Factors Causing Cancer
smoking
obesity
radiation
diet
alcohol use
chemicals
How is the Epidemiology of Nutrition and Cancer Found?
the links between cancer, nutrition and migration
- someone moves from low risk to high risk areas
- new local diets are adopted
What 7 Cancers can Unhealthy Diets Lead to?
Oral and Upper Throat
Larynx
Oesophagus
Lung
Stomach
Bowel
What are the 3 Dietary Cancer Causative Factors?
- Genotoxic agents in food - dietary carcinogenics
- Lack of specific nutrients
- Public health Issues - alcohol and obesity
Give 3 Genotoxic Contaminants and Where they are found in Food
Aflatoxin and Fumonsin B
- mold growing on poorly stored food
Heterocyclic Amines
- high heat cooked meats like BBQ
Polychlorinated Biphenols
- occur in farmed salmons
- in a process called biomagnification, goes through the food chain
Which Deficient Nutrient Increases the Risk for Colorectal Cancer
Vitamin B9 (Folate)
How does Folate Deficiency Increase risk for Cancer? (6)
- hypomethylation of DNA
- inhibits production of dTMP
(deoxyythymidine monophosphate)
= imbalance of nucleotide availability
- Uracil incorporated into DNA due to no Thymine
- DNA repair to remove u and place with T but makes DNA breaks
= increased frequency of mutations
What 4 Cancers are Alcohol a Risk Factor?
oral, breast, colon and liver
How does Alcohol Increase the Risk for Cancer?
Ethanol is metabolised into Acetylaldehyde by endogenous alcohol dehydrogenase
- binds to DNA
= DNA adducts - have a cancer chemical bound to it - causes mutations
After Drinking Alcohol, How much more Acetylaldehyde is Present in the Saliva?
100x
What are the 6 Common Cancer Tissues from Which Obesity Has a High Risk association
- breast
- colorectal
- endometrium
- oesophagus
- kidney
- liver
- multiple myeloma
What are the Proposed Mechanisms for How Obesity Leads to Cancer?
1) endocrine organ, secretes hormones like oestrogen = links to breast cancer
2) adipose increases storage for carcinogens
3) induces a chronic inflam response, more IL6 and TNFa
4) shift in gut microbiome, increased production of deoxycholic acid bacterial metabolism, reaches liver, DNA damage
What are Antioxidants?
compounds that significantly inhibit or delay the damaging action of ROS, may have a protective effect against cancer
Give 4 Phytochemical Antioxidants
Vitamin C
Isoprenoids
Flavonoids
Organosulfur Compounds
= plant derived
What is Isothiocynate?
a micronutrient from vegetables that can affect gene expression
