Neoplasia Flashcards
what is total failure of the development of an organ or tissue
aplasia
what is a cell mutation
a change in the gentic make-up (genotype) of a cell:
* heritable (gametes)
* somatic
what conditions can cause mutations in a cell
- spontaneous
- chemicals/radiation
most impair cell survival and result in cell death, but some mutations give the cell a growth advantage
what do oncogenes do
stimulate cell division
which genes inhibit cell division
tumour suppressor genes
term for cancer
malignant neoplasm
what is histogenesis
formation of tissues due to cellular differentiation
what is the term for malignant tumours of epithelium
carcinoma
what is the term for mesenchymal tumours
sarcoma
how does a malignant neoplasm differ from a benign neoplasm
- more autonomous
- invasion and metastatic spread
- resistant, can be fatal
what are the genes called that are capable of causing cancer in response to stimuli
oncogenes
mutated forms of oncogenes, approximately 100 known oncogenes
what is oncogenesis
transformation of normal cells into cancer cells
what do proto-oncogenes do
enourage and promote normal cell growth and division
what does the ras gene do
responsible for cell growth
what is the p53 gene (4)
- suppresses tumour growth
- exists on chromosome 17
- stimulates the expression of several genes, including a key promoter of apoptosis
- abnormalities of this gene have been detected in many common cancers including colon, breast and lung
what do oncogenes do (4)
- overproduction of growth factors
- flood cell with replication signals
- uncontrolled stimulation in intermediary pathways
- unrestrained cell growth driven by elevated levels of transcription factors
how are proto-oncogenes activated
- point mutation
- chromosome rearrangement
- gene amplification
- viral insertion
what is the role of growth factors
cell proliferation
what regulates the passage of growth signals from outside the cell to inside
Ras proteins in the plasma membrane
what can mutated Ras proteins cause
continuous growth signal - found in 30 of human cancers
what are the complications of benign neoplasms
- pressure
- obstruction
- ulceration
- haemorrhage
- malignant changes
- infarction
- infection
- rupture
- hormone production
direct spread of malignant tumours
- interstital
- lymphatic
- venous
- coelomic
- CSF
- epithelial (rare)
how can malignant tumours be managed
- surgery
- radiotherapy
- chemotherapy
- hormone manipulation
