Biology and the Molecular biology of Cancers Flashcards
Objectives: To examine: the prevalence of cancer the lifestyle causes of cancer possible approaches to cancer prevention the cellular basis of cancer
what is the new cases of cancer in 2013
352,197
how many preventable cases of cancer are there
42%
what are the new cases of cancer worldwide in 2012
14 million
why is the number of cancer increasing in the population
due to early diagnosis and early detection
people are also living longer
what are the causes of cancer
smoking poor diet leading go obesity XS alcohol intake UV rays sedentary lifestyle
how many cases of cancer can be prevented by lifestyle changes
more than 4 out of 10 cases
what is the connection between nutrition and cancer
A healthy balanced diet with plenty of fibre, fruit and vegetables and less red andprocessed meat and salt can help cut cancer risk.
which studies can we use to see which foods can increase or reduce the risk of cancers
EPIC study( European Prospective Investigation into Cancer and Nutrition)
risk of which cancers can be reduced by eating fruits and veggies
mouth cancer oesophagus lung larynx stomach cancer
which minerals and vitamins are contained in fruits and veggies
carotenoids, folate, vitamin C, vitamin E, selenium, flavonoids and various other phytochemicals (chemicals found in plants).
what do the vitamins and minerals in fruits and veggies do
Mopping up harmful chemicals that could potentially damage DNA.
Helping with repairing DNA.
Blocking the formation of cancer-causing chemicals.
what are checkpoint inhibitor drugs
revolutionary drugs which increases survival rate different for certain types of cancer
what does obesity lead to
generally leads to chronic inflammation and that can lead to cancer
what is the risk rate of cancer when eating a diet low in fruits and veggies
1 in 20
which vitamins are free radicals
vitamin E
Vitamin C
Why might it be difficult to eat healthily
Socioeconomic factors like fruit and veggies are very expensive
How do we prevent developing bowel cancer
Bowel screening for people above the angle of 40
Why are anti oxidants important
During oxidative phosphorylation of aerobic respiration- free oxygen species are produced and these can bind to compounds in the body- eg if it binds to DNA can cause mutations
Which group of people is bowel cancer less common in
People who eat a lot of fibre
What are the benefits of fibre
Fibre increases the size of stools, dilutes their contents and helps people have frequent bowel movement
This reduces the content time between the bowel and harmful chemicals in the stools
Fibre may also help gut bacteria produce helpful chemicals that change the conditions in the Bowel
what are phytochemicals
chemicals found in plants
what is a big constituent of faeces
cells from the colon and harmful products
how does eating too much meat increase the risk of cancer
chemicals found in the meats and some are natural and some added in the cooking or preservation stages
eating too much red meat increases the risk of which types of cancer
pancreatic
stomach
bowel
what are some natural chemicals in red meat
haem and myoglobin
what is dangerous about too much haem
may damage cells in the bowel or fuel the production of harmful chemicals by bacteria in the gut.
why dont white meats increase the risk of cancer
because they have less haem
which chemicals are used to preserve meats
nitrate and nitrites
what can nitrities be converted to in the liver
cancer causing chemicals called N-nitrosocompounds(NOCs)
what is converted into N nitroso
nitrites
why does grilling meats at high temperatures increase cancer risk
can produce cancer causing chemicals called heterocyclic amines(HCA) and polycyclic amines (PCA)
which reaction can occur when grilling meats
the maillard reaction which the proteinsand sugar in the n=meat are converted into advanced glycation end products which are tasty
what percentage of cancers have a nutritional connection
35%
what is the risk of cancers when lifestyle factors such as smoking and exercise are included
as high as 85%
what do cancer cells contain
genetic damage- the initial event leading to tumorgenesis
how does cancer progress
by a two hit theory
what is the two hit theory of cancer
normal cell—–>pre cancer—->cancer—-> invasive cancer cell
what is tumorgensisis
the process fo converting normal cells into cancer invading cells
what is the first stage of the two hit theory
normal cell—> pre cancer
this is called initiation- mutation 1
what is the second stage of the theory
pre cancer—-> cancer
promotion- mutation 2 stage
what is the final stage of the cancer progression stage
cancer- invasive cancer
this is the progression stage eg metastasis
how do people usually die from cancer
when it metastasises and forms secondary tumors
what are the two type of genetic damage found in cancer cells
- Dominant and the genes have been termed proto-oncogenes.
- Recessive and the genes variously termed tumor suppressors, growth suppressors, recessive oncogenes or anti-oncogenes.
what are the changes in cells that cause cancer (6 THINGS)
- sustained angiogenesis
- self sufficiency in growth signals
- insensitivity to antigrowth signals
- tissue invasion and metastasis
- limitless replicative potential
- evasion of apoptosis
what is the development and metastasis of human colorectal cancer
a polyp grows on the colon wall benign precancerous tumor grows a class II benign adenoma grows a class III benign adenoma grows a malignant carcinoma develops
what is limitless replicative potential
cells do not reach the end of the replicative potential due to the fact that Telomerase increases the telomere size
Cancer cells can activate telomerase which stops them from dying
which cells is telomerase important
eg in sperm cells
why is henrietta lacks important
HeLa cell line- immortal cell lineage she had a
epidermoid carcinoma
what would happen if sperm cells did not have telomerase
after 4/5 generations we would not be able to reproduce
how do we detect colon cancer
colonscopy- can detect pre cancerous lesions which can be removed in procedure
what is metastasis
the access of cells from primary tumour into circulation and the cells acquiring certain properties which allow them to survive in different types of tissue and be undetected by the immune system
what is antiangiogenic therapy
inhibits the growth of new blood vessels.
what size does the tumour grow till
2mm- as if it is bigger the inside of tumour dies due to lack of o2
what is angiogensis
the formation of blood vessels
what are common sites of cancer metastasis
brain respiratory lymph nodes liver skeletal
what are the symptoms of metastasis in the brain
headaches
seizures
vertigo
what are the symptoms of metastasis in the respiratory system
cough
hemoptysis- coughing up blood
dyspenea- shortness of breath
what are the symptoms of metastasis in the lymph nodes
lymphadenopathy
what are the symptoms of metastasis in the liver
hepatomegaly- enlargement of the liver
jaudice
what are the symptoms of metastasis in the skeletal
pain
fractures
spinal cord compression
what is the difference and distrinction between the terms proto-oncogene and oncogene
the activity of the protein product
what is a proto oncogene
a gene whose protein product has the capacity to induce cellular transformation given it sustains some genetic insult eg by a mutation
what is an onco ogene
sustained some genetic damage and therefore produces a protein capable of cellular transformation
which is the cancerous form of the protoncogene
the oncogene
what is the classification of proto oncogenes
- Growth Factors
- Cell receptors/ProteinKinases
- Membrane Associated G-Proteins/2nd Messengers
- Nuclear DNA-Binding/Transcription Factors
- Other genes involved in DNA repair/cell-cycle control
how do proto oncogene activate into a oncogene
gene mutation or retroviral integration.
how are proto oncogene classified into different groups
by normal functions within cells
what do proto oncogene control in cells
CELL GROWTH
PROLIFERATION
DIFFERENTIATION
what is a v- proto oncogene
signify viral origin which are resident in transforming retroviruses
what is c- proto oncogene
homologous genes of cellular origin comes from a mutation rather than a virus
