Cancer Bio Flashcards
epigenetics
- methylation
- histone modification
what does it mean that cancer is epistatic?
- one lesion per pathway required
nearly 100% of cancer has which inactivation
- p16^INK4a-Rb
90% of cancer has which inactivation?
- p53
how does inactivation occur
- deletion of the gene
- point mutation fo the gene
- silencing of the gene
- by promoter methylation
proto-oncogene type of gene
- high conserved eukaryotic gene
proto-oncogene important in
- cellular growth and development
proto-oncogenes become oncogenes by
- over/under expression
- mutation
cellular oncogenes involved in
- cellular genes involved in development and/or maintenance of malignant phenotype
viral oncogene
- viral genes able to transform cells
oncogenic mechanisms
- growth factors
- signal transduction
- cell cycle control
- regulation of gene expression
examples of professional tumor suppressor genes
- p16^INK4a
- p53
tumor suppressors role in normal development
- serve only to prevent transformation
Li-fraumeni syndrome
- hereditary predisposition to cancer
role of p53 gene
- arrests cell cycle when DNA damage occurs
- promotes apoptosis in damaged cells
what is the most commonly mutated gene in cancer
- p53
people born with Li-Fraumeni syndrome
- born with one abnormal copy of p53
formation of cancer requires that
- a sub-population of neoplastic cells maintain the ability to self renew
- malignant cells not die
cellular adaptations
- can be pathologic and physiologic
- hyperplasia
- hypertrophy
- metaplasia
abnormal growth
- always pathologic
- dysplasia
- neoplasia
hyperplasia
- increase in cell number
hyperplasia usually associated with
- increase in tissue mass (hypertrophy)
hypertrophy
- increase in cell size
- production of new sub cellular components
what is hypertrophy not
- hypertrophy is not swelling
metaplasia
- change of one differentiated cell type into another differentiated cell type
what type of response is metaplasia
- adaptive response
reversibility of metaplasia
- usually reversible
dysplasia
- atypical proliferation of cells with abnormal appearance and disorderly rearrangement
dysplasia - abnormal appearance
- pleomorphism
- nuclear enlargement
- nuclear irregularity
- hyperchromasia
dysplasia - nuclear enlargement
- increased nuclear-to-cytoplasmic ratio
disorderly arrangement
- loss of polarity
- loss of maturation
- abnormal location of mitotic figures
neoplasia
- abnormal growth of tissue
- excessive growth of tissue
- uncoordinated and autonomous
anaplastic
- lack of cellular differentiation
benign neoplasms
- growth without invasion of spread
growth of benign neoplasms
- grow slowly
- usually remain localized
morbidity of neoplasms caused by
- size
- anatomic location
- production of hormone or other cell product
nomenclature for benign neoplasms
- add -oma
histology of benign neoplasms
- resembles normal counterpart
paraneoplastic syndrome symptoms due to
- symptoms not due to local presence of neoplastic cells
- but systemic effect
- secretion of humoral factors by tumor cells
paraneoplastic syndrome most commonly associated with
- malignant neoplasms
cells in dysplasia
- abnormal appearing
- abnormal cellular architecture
reversibility of dysplasia
- reversible
carcinoma in situ
- dysplastic changes involving full thickness of epithelium
cells in carcinoma in situ
- don’t extend beyond basement membrane
carcinoma
- malignant cells with atypical morphology extend beyond basement membrane
nomenclature for malignant neoplasms in mesenchymal cells
- sarcomas
nomenclature for malignant neoplasms in epithelium
- carcinoma
mixed neoplasms are called
- teratomas
most common of solid tumors
- carcinomas
sarcomas are more common in
- children
- adolescents
histologic grade refers to
- level of differentiation
high histologic grade refers to
- poorly differentiated
anatomic stage refers to
- extent or spread of the tumor
anatomic staging system
- tumor 0-4
- nodes 0-4
- metastasis 0+
all cancers demonstrate
- dysregulation of proliferation
- DNA repair
- apoptosis and differentiation
