Tumour Flashcards
What are the layers of embryonic development?
Ectoderm
Mesoderm
Endoderm
What is mucosa?
The epithelium and the connective tissue
What are the 2 main types of epithelium concerning cancers?
Squamous epithelium
Glandular epithelium
What is hyperplasia ?
Increase in the size of organs due to the increase in number of cells
Pathological or physiological
What is hypertrophy?
Increase in organ size due to increase in cell size
What is atrophy?
Decrease in organ size due to decrease in size of cells
What is metaplasia?
Complete transition of 1 differentiated cell to another differentiated cell
What are examples of tumour?
Swellings due to masses or inflammation
What is neoplasia?
Abnormal growth of tissue due to uncoordinated proliferation
Persists even after cessation of stimuli
Benign neoplasm
Neoplasm that doesn’t invade
What’s carcinoma?
Malignant neoplasm in epithelium
What is sarcoma?
Malignant neoplasm in adipose tissue
What is adenoma?
Tumour in glandular of epithelium
What is papilloma?
Tumour in the skin
How does papilloma look?
Finger like projection
What does the suffix -Oma?
Benign tumour
What does carcinoma mean?
Malignant epithelium cancer
What are the exceptions to generic cancer naming?
Leukaemia is malignant.
Lymphoma is malignant alongside myeloma, glioma and melanoma
What is sarcoma?
Malignant cancer in connective and muscle tissue (bones and fat included)
How can you identify carcinoma from histology?
- Looks messy
- can see intercellular bridges as the cells are pushed out
A benign tumour is part of the neoplasm. True or false
True.
How is the growth rate of benign and malignant tumours different?
Benign tumors grow much slower
How are the borders of tumours (malignant and benign) different?
Benign ones are encapsulated hence are smooth whilst malignant is irregular
How do benign tumours spread compared to malignant ones?
Benign ones are confined the by basement membrane whilst malignantones invade locally (adjacent cells) and spreads over a distance (metastasis)
Do malignant and benigntissue resemble the normal tissue?
Benign are well differentiated and malignant are poorly differentiated
What are the treatments and recurrence for benign tumours
Benign tumours require surgery but has alow chance of recurrence whilst malignant is likely to reoccur and needs chemo or radiotherapy alongside surgery
How to identify benign and malignant tumours?
Benign are well defined whilst malignant is messy and depending on the location you can tell if it’s secondary
Osteoma is the most common bone cancer True or false
False. Bones tend not to yet cancers its often osteosarcoma and has glandular epithelial looking cancer
How does adenoma look?
Glandular epithelium.
Lobes with a lumen in between
How do cancer cells look under a microscope ? (5)
- Pleomorphic
-Hyperchromatic - coarse chromatin
- highly mitotic and abnormal forms
- disorganised structure
What does pleomorphic mean?
All the cells have a different shape and sizes
What does hyperchromatic mean?
The nucleus stains dark in colour
What is coarse chromatin?
Lumpy chromatin
What are behaviours of cancer cells?
- Unregulated growth
- loss of cohesion
- immaturity
- immortality
Why do cancer cells have a lack of cohesion?
They are able to break off and spread
How do cancer cells hide from the immune system?
They temporarily hide their cell/cancer markers
How are cancer cells immortal?
Gain the ability to hide from and avoid telomeres
How do cancer cells invade and spread? (4)
- Lack of cohesion between the cells
- over densely packed (with collagen) so it requires enzymes to breakdown and remodel the connective tissue to grow
- it uses the new blood cells which the cancer created as an escape route
- also uses lympathic system to move
How do cancer cells get nutrients?
They induce angiogenesis. They make new blood vessels by secreting certain protein
How do cancer cell metabolise?
The main aim of a cancercellisto grow but they live in low nutrient environments due to lack of blood vessels. So cancer cells change their normal metabolism
How do mutations affect cancer cells?
Cancer cells divide quickly hence are likely to get mutations..
If its a bad mutation, the cell dies.
If it’s a good mutation, the cell benefits and becomes dominant. The cancer cell begins to clone itself
Why do cancer cells cause inflammation?
Cancer cells produces molecules for inflammation to prevent damage to the cancer cell itself.
What is apoptosis?
Programmed cell death
Active process where the cell breaks down into vesicles to prevent toxic intercellular things from entering connective tissue.
What is necrosis?
Premature cell death - passive process and messy
What are proto-oncogenes?
They are normal cells but have the potential to become cancer cells if there is overexpression or mutations
What are oncogenes?
Normal cells which mutated and causes cancer
What are tumour suppressors?
Protective molecules that detect DNA damage and inhibit cell growth/division eg. P53
How do cancers spread?
- Local spreads-spreads to adjacent cells
- lymphatic spread- spreads through the lymphatic system
- haematogenous spread-spreads through the blood (through the newly formed vessels)
- trans-coelomic spread
What is trans-coelomic spread?
- spreads within the body cavity
Eg. Lung cancer spreads the to pleural cavity
Or it is peritonealcabdomen)
What are common places for metastasis?
Liver (due to clearing out toxins from blood)
Brain
Bone ( rich blood supply)
Adrenal gland (melanoma and lung and kidney)
What are part of the peritoneal system?
Ovaries and abdominal organs
What are the local effects of a tumour the brain ?
Coma
Seizure
Confusion
Regardless of metastatic, malignant or benign
What are the local effects of tumours in the colon ?
Constipation tumour is in the way
Haemorrhage- inducing new blood vessels which are more likely to get damaged
Diarrhoea- tumour leaks fluid
What are the local effects of tumours in the bone?
Anaemia- specialised tissue that produce RBC are damagaed
Pain- tumour presses on nerves
Fractures- cancer affects work of osteoclasts and osteoblasts
What are the local effects of a tumour in a liver?
Coagulopathy - protein which are involved in clotting are affected since the liver synthesis them.
Jaundice-
Cancer blocks the bile duct
What is cachexia?
You lose muscle mass more than fat due to alterations in the normal metabolism
It can’t be fixed by changing your diet
How is DVT potential sign of cancer?
Cancer increases coagulation leading to more blood clots
What is paraneoplastic syndrome?
Abnormal production of hormones from tumours - like ADH and ACTH.
This causes an autoimmune response and results to nerve damage or moon face
How can we detect cancer in the early stages?
Some cancers have pre-cancers which are like precursors to cancers
What is dysplasia?
Disorderred cell growth due to genetic reasons which doesn’t invade
What is carcinoma in situ?
It’s a pre cancer which looks abnormal and hasn’t spread to nearby tissue
How is cervical cancer prevented?
HPV vaccines
Cervical screening by taking swabs to find cancer dysplasia
What are signal transduction molecules?
Messenger molecules which are captivated by receptors at the cell membrane and cause further reactions the cytoplasm and nucleus
What is BRAF?
Signal transduction molecule is part of a long chain reaction
How are molecules activated and inhibited?
- Phosphorylation
- Conformational shape
What are transcription factors?
Proteins involved in regulation of transcription
Where do transcription factors bind?
Promoters on DNA
How do transcription factors regulate transcription?
They often activate enzymes which transcribe DNA to RNA
What are the regulatory sequences?
Part of DNA which regulates transcription of the gene eg the promoter
What are the phases of the cell cycle?
G1 S G2 M
What are the checkpoints in the cell cycle?
G1 G2 and the M checkpoint
What happens at both checkpoints?
G2 check if it’s correct DNA and cell is big enough
M check if the DNA is correct and the chromosomes are lined down the middle
What is the effect of growth factors?
It is to push the cell along the G1 phase towards the checkpoint by binding to cell surface receptors and causing reaction cascades
How does the cell cycle progress?
At the restriction point
Phosphorylation of a protein therefore forcing out the bound E2F molecules. The E2F molecules binds to DNA regulatory sequences and the cell cycle happens as normal
What is the key protein with the E2F on it?
Retinoblastoma gene product
What does retinoblastoma do in it’s normal state?
Act as a tumour suppressor gene as unless it’s phosphorylated it doesn’t allow the cell cycle to happen
Growth factors are the only reason for G1 progression
True or False
False other factors like glucose and amino acid levels play a crucial role by inhibiting or promoting phosphorylation
What is HER 2?
It is typically an inactive receptor which binds to a cell surface receptors when a growth factor binds to which activates the pathway
What happens when there is DNA damage?
P53 increases which indirectly blocks the formation of phosphorylated retinoblast gene products hence prevents G1 which blocks the checkpoints
How is DNA damage repaired ?
Mismatched repair genes codes for proteins that recognise and replace the DNA base. For example the MLH1 gene
It induces P53 which stops the cell cycle.
What is MLH1 gene?
The products of the mutated gene induces P53 production to stop the cell cycle
Proto oncogenes tend to be growth factors.
True or False
True
What is a tumour suppressor gene?
A gene that regulates cell division by controlling or blocking proto oncogenes
How do cancers happen even with the tumour suppressor gene?
The thmour suppressor gene can get deactivated by environmental factors or can get mutated
How do muatations cause cancer with respect to oncogenes?
Mutations increase the amount of oncogene product or growth factors
Signal transduction world all the to e inste@d of only when triggered
How do mutations cause cancers with respect to the tumour suppresor gene?
Stop proteins like retinoblast from working
A viral protein binds to the protein. to make it stop workimg
MLH1 mismatch repair protein stops working
What else apart from mutation causes cancer?
Genes
Retinoblastoma malignant eye tumour
Give example of mutagens.
Infection
Radiation
Chemicals
How can HER-2 cause cancer?
Overexpression creates lots of growth factors as pushes G1 forwards
What is the most common mutations of BRAF in malignant melanoma ?
An amino acids changes to valine at number 600
So it’s called BRAF V600
This turns on BRAF all the time
How many retinoblast gene copies do we have?
2
What is MLH1 gene?
It’s a mismatch repair gene which protein product is involved in correcting DNA code
How does smoking cause cancer?
The chemicals in cigarettes are broken down into carcinogenes in the liver
This gets released into circulation and DNA gets damages or mutated
How does HPV cause cancer?
Infects the cervix and produces E6 which binds and inactivate P53 so there is uncontrolled cell division which causes pre cancer and then cancer
What does c-myc do?
Increases proteins to push the cell cycle
Increases proteins to stop cell death
TIGHTLY CONTROLLED
How can c myc cause cancer?
It breaks off it’s normal chromosome and binds to another one
What is the normal c myc chromosome?
8
What new chromosome might c myc bind to to create a BIG problem?
14 the immunoglobulin sequence which releases B and T cells
Why is it dangerous for c myc to bind to chromosome 14?
Chromosome 14 releases a lot of B and T cells for our immune system so it would produce a lot of c myc protein which pushes forward the cell cycle
What is translocation?
Parts of the chromosome move and join onto other ones
What type of cancer does the move of c myc from 8 to 14 cause?
Lymphoma
How is translocation denoted?
t(8;14)
How does alcohol cause cancer?
Large amounts gets converted to acetaldehyde which gets into the systemic circulation and breaks double stranded DNA
What happens in the epstein barr virus?
Virus infects B cells
B cells proliferate
C myc is translated onto B cells
To produce cancer
What is multistep cancer?
Various factors combining together to lead to cancer
Why does cancer increase coagulation?
Because the damage to the tissue causes the clotting process to start
