Biology and molecular biology of cancer I Flashcards
Why os the numer of people with cancer increasing?
- Better diagnosis tecnique
2. People are living longer
give some of the biggest causes of death world wide
- Heart disease
2. Cancer
How many new cases of cancer were their in 2013?
352,197
How many deaths did cancer cause in 2012?
161,823
How many cases of cancer could be prevented in the uk through lifestyle change?
More than 4 in 10 cases
Give examples of lifestyle choices that can increase a persons risk of getting cancer?
- Smoking
- Diet
- Obesity
- Alcohol
What is the connection between diet and cancer?
A healthy balanced diet with plenty of fibre, fruit and vegetables and less red and processed meat and salt can help cut cancer risk
Do we knoq which foods lower or raise the risk of cancer
Very few specific food have been convincingly shown to raise or lower the risk of cancer
Give n example of a study scientist are conduction to see which foods may reduce the risk of cancer
The EPIC study (European prospective investigation into cancer and nutrition)
What is the link between fruit and veg and cancer risk
Research suggest snearly 1 in 20 cancers in the uk may be lined to diets low in fruit and veg
Name some nutrients found in fruit and veg
carotenoids, folate, vitamin C, vitamin E, selenium, flavonoids and various other phytochemicals (chemicals found in plants).
How do the nutrients in fruit and vegetable help reduce cancer risk
- Mopping up harmful chemcals that could potentially damage DNA
- Helping with repairing DNA
- Blocking the formation of cancer causing chemicals
Reseach has shown that _______ cancer is less common in people who eat a lot of __________
Bowel cancer
Fibre
How does fibre help protect against bowel cancer?
- Fibre increases the size of stool, dilutes their content and help people have more frequent bowel movements
- Reduces the contact time between the bowel and harmful chemicals in the stools
- Fivre may also help gut bacteria produce helpful chemicals that change the conditions in the bowel
- All of these things help to reduce the risk of cancer
Eating loads of P_______ M____ can increase the risk of B_____ cancer and posible S____ and P_______ cancer
Processed Meat
Bowel cancer
Stomach and pancreatic cancer
What does red meat include?
All fresh, minced and frozen beef, pork and lamb
What does processed meat include?
Ham
Bacon
Salami
Sausage
What is present in red and processed meat that can cause damage to us?
Haem
Nitrates and nitrites
Heterocyclic amines
How can Heam increase our cancer risk?
May damage the cells in the bowel or fuel the production of harmful chemicals by bacterial in the gut
How can nitrites and nitrates increase our cancer risk?
In the bowel nitrites can be converted into cancer causing chemicals called N-nitroso compounds (NOCs)
Why are nitrites and nitrates added to meat?
To preserve processed meat
What happens when we cook meat at high temperatires?
Cooking meat at high temperatures such as grilling or barbecuing can produce cancer-causing chemicals called heterocyclic amines (HCAs) and polycyclic amines (PCAs).
What connection has the national cancer institute found?
That at least 35% of all cancers have a nutritional connection
Why foods are important for health?
- Foods that come from the plant kingdom as they have protective botanical factors
- Antioxidants, anti-carcinogens and bioflavonoids
Give some examples of food rich in botanical factors anf phyonutrients
Berries Dark leafy vegetables Citrus fruits Legumes Whole grains
Name a theroy that describes and explains cancer progression
Two hit theory
Briefly outline the Two hit theory
- Initiation: Normal cells mutate into pre cancer cells
- Promotion: Pre cancer cells mutate to form cancer cells
3 Progression: Cancer cells multiple leading to invasive cancer
Name the 2 types of genetic damage that can be found in cancer cells
- Proto oncogenes
2. Tumour suppressor genes
Describe proto oncogenes
They are dominant
Describe tumour suppressor genes
They are recessive
Give some other names of tumour suppressor genes
Growth suppressor
Recessive oncogenes
Anti oncogenes
Give some changes in cells that can cause cancer
- Self sufficiency in growth signals
- Insensitivity to antigrowth signals
- Evasion of apoptosis
- Limitless replicative potential
- Tissue invasion and metastasis
- Sustained angiogenesis
How can cancer develop in the colan?
- Normal colon cells lose their APC tumour suppressor gene
- Te K-ras oncogene is activated
- The tumour suppressor gene is lost in the DCC region (chromosome 18)
- p53 tumour suppressor gene is lost
- a maignant carcinoma forms for polyp in the colon wall
- Tumour cells invase blood vessels allowing metaastasis
Name some common sites of cancer Metastasis
1. Brain 2, Respiratory 3. Lymph nodes 4. Liver 5, Skeletal
Give some symptoms a patient would have if cancer had Metastasised in their brain?
- Headaches
- Seizures
- Vertigo
Give some symptoms a patient would have if cancer had Metastasised in their respiratory system?
- Cough
- Hemoptysis
- Dyspnea
Give some symptoms a patient would have if cancer had Metastasised in their lymph nodes?
Lymphadenopathy
Give some symptoms a patient would have if cancer had Metastasised in their liver?
- Hepatomegaly
2. Jaundice
Give some symptoms a patient would have if cancer had Metastasised in their skeletal system?
- Pain
- Fractures
- Spinal cord compression
What is the distinction between the proto oncogenes and oncogenes related to?
Related to the activity of the protein product of the gene
What is a proto oncogene?
A gene whose protein product has the capacity to induce cellular transformation given it sustains some genetic insult
What is an oncogene?
A gene that has sustained some genetic damage and therefore produces a protein capable of cellular transformation
Name the 5 ways we can classify proto oncogenes
- Growth factors
- Cell receptors/ protein kinases
- Membrane associated G proteins/ 2nd messengers
- Nuclear DNA binding/ transcription factors
- Other genes involved in DNA repair/ cell cycle control
How is a proto oncogene activated into an oncogene?
By gene mutation or retroviral integration
What have proto oncogenes been identified at?
Proto-oncogenes have been identified at all levels of the various signal transduction cascades that control cell growth, proliferation and differentiation.
How are resident proto oncogenese designated?
With a V to signify viral origin
How are proto oncogenes with cellular origins identified?
With a C to indicate their cellular origin
