Cancer Flashcards
What is cancer?
An uncontrolled growth of cells - tumour
what are 2 kinds of hyper-proliferated lesions, explain them
- benign: cyst/wart, not life threatening in north America
- malignant: grow with no control, has an irregular shape, were most worried about these
What is the number 1 cause of death in Canada
Cancer
Why are males more likely to die from cancer than women? What year was it most similar for genders?
they are more stupid!
They die from mostly lung cancer, they smoke more an average compared to women
1930’s
what are 3 types of cancer treatments?
chemo, radiation, surgery
very unpleasant!
Has the death rate for cancer decreased at all since the past?
No. we are not successful at treating cancer much better for other diseases
what are the cancers that have decreased in men and women overtime?
men: stomach,
women: uterine, stomach
explain Cell Division for normal cells
it is regulated
has a cap for 5 divisions
divide only on demand
the cells must touch similar cells (tissue)
explain Cell division for Cancer cells
uncontrolled
divide as many times (50+)
they can move around (mobile)
Why are cancer cells useful to study in labs?
They are immortal, can keep them if removed from a person,
What is an example of cells we still use today in research - Henrietta Lacks
HeLa Cells
- cervical cancer cell (tumour was removed and kept growing in a lab
they are still used today - her cells out lived her
how many years does it require for cancer to develop? and why does it take long?
20 years
it requires 8-10 mutations in the same cell, and our body protects against mutations
What is a cell mutation? and biological regulation
it is a loss of function of a cell - proteins stop working properly
the only way to treat it is by killing it… but the cancer is YOU
biological regulation is the way our bodies balance for survival - controlled by activation (ON) and suppression (OFF) pathways at the same time
What is the accelerator and breaks in cell division regulation?
the stimulation says “time to divide” and the repression says: don’t divide”
What happens to the accelerator and breaks with cancer?
The brakes are broken and the gas pedal is on the floor
what is the role of RAS?
It is a common ON/OFF switch for cell division and is stuck on “ON” for 30% of tumous
What is p53?
A breaking protein - it doesn’t work in 50% of tumors and there is A LOT of trouble if it’s broken.
What is Apoptosis and what happens to it when the p53 doesn’t work
It is a programmed cell death to protect against tumor formation ex: wound healing. IF the p53 is broken then apoptosis doesn’t work
What happens when cells hit 50 divisions, but cancer interferes?
The cells die after 50 divisions and the tips get cut off… but cancer regrows these tips as a malfunctioned cell
What is the gene’s role in making proteins? what happens with mutation?
it is an instruction to make proteins with codons (amino acids) and string them together = protein.
mutation= type in the gene = wrong shape of protein
protooncogenes = oncogenes
some people may be more susceptible depending on their sequence - behaviour + body type
explain alcohol’s role in cancer
acetaldehyde = carcinogenic
ex: 2 people-
1- has equal amounts of enzymes
2- has a small amount of the second enzyme -> gets more acetaldehyde
- but they can also be at a lower risk cause these people don’t tend to drink often
Tobacco’s role in cancer
4800 chemicals, 400 toxic, 40 corcinogenic
causes cancer by burning toxic chemicals (ex: polonium 210)
This comes from fertilizers - uranium
alpha emitter - safe on the outside of the body: plastic brushed, spark plugs, toy in kix cereal
heat burns the polonium and turns it to vapor, when it’s inhaled the body temp cools it back down into metal form that welds into place in the lungs
Benzopyrenecarcinogenicity
combustion of byproducts = dangerous and react chemically with DNA - changes its structure
why did women smoke later than men?
They created advertizements to reach the larger audience (1970’s)
Diet/Obesity
- food
we cook for safety + flavour - controlled burning
meet darkens as you cook it (combustion) - creates materials that affect our DNA
Fruits and veggies activate pathways for bad materials which is more safe
FIBER: promotes passage of waste and not the absorbant of dangerous substances
Added weight means organs are too small for the body
- we eat way more processed foods now (fat, sugar, starch)
- we eat BIGGER portions, more than we need
Viruses
15%
What’s the #1 cancer in Canada?
skin cancer, exposure to UV light
Environmental exposure
artificial:
- pesticides, preservatives
- small % of risk
- less risk but exposed to them more
natural:
- more carcinogenic
- but we get exposed to them in smaller quantities
Aflatoxin and Phorbol
- mold that grows on peanuts
- a plant, extremely dangerous, bad skin lesions by touching it, used to cause cancer in a lab… study rats
Why is cacer difficult to target?
Selectivity - drugs don’t know the difference between a normal and cancerous cell
Why are drugs created to operate on cell division?
because we know cancer cells grow fast so we can create drugs to target fast cells first
- a poison that kills cancer faster than the patient
will cancer drugs have side effects?
100% of the time
The first cancer drug ever: Mustard Gas
- used as a chemical weapon during the war
- destroys tissue, blistering
transported on a ship that sank and killed many but the survivors demonstrated something interesting - they has fewer white blood cells - leukemia has more WBC - so was this a cure?
Most common cancer drug:
investigating the effect of electric fields on bacteria
- found that when you zap bacteria, some cells stop dividing
- found that it was die to the platinum electrode they were using - very corrosion-resistant but it actually generated a chemical called pyrones salt (cisplatin) which reacts with DNA and stops fast growing cells from dividing and was succeccful on tumors
Interetsing drug:
Yew bark story - Taxol
wanted to search for poisons in nature - cause of penicillin
Yew bark caused cancer
- taxol the active substance was toxic - and effective for curing breast cancer
impossible to make the synthetic version of it
and Yew trees you needed 13,000 for 1kg so would need 360,000 trees/ year
Taxus Baccata= Europeen Yew
not in the bark but in the leaves
- synthesized to make the drug they wanted
- Rober Holton from FSU created the idea of semi-synthesis
taxol is now manufactured using cell structure and genetic modification