Cancer Flashcards
Tumor
Lesions that occupy space and may or may not be an abnormal tissue mass (neoplasm)
Neoplasm
- abnormal tissue mass that results from dividing cells with abnormal gene regulation
- Benign or malignant
Cancer
Malignant neoplasm
Metastasis
Another cancer growth at a location different from the original neoplasm
What are the steps of cancer (in order)
1) Initiation
2) Promotion
3) Progression
Initiation (cancer)
- Genotoxic event (chemicals, radiation, viruses)
- Mutation of one or more genes controlling regulatory paths/sequence change
- undetectable
- Irreversible
- Can be the result of oncogene activation or suppression of tumor suppression genes
Promotion (cancer)
- Epigenetic event (gene activation/repression, leading to clonal expansion of certain gene)
- Enhancement of signal transduction pathways that indicate continuous growth
- Undeteceted
- Reversible in early stage (i.e. eating right/phys. activity)
Progression (cancer)
- Clastogenic event
- Continuous proliferation and change of the unstable karyotype
- Detected
Genotoxic event
Change in DNA sequence
Epigenetic event
Changes kin gene expression that are not the result of changes in the DNA sequence (i.e. DNA methylation and histone modification
Clastogenic event
- changes in karyotype brought on by mutation
- leads to rearrangement/deletion of genetic material, amplifications
Hallmarks of Cancer
1) Insensitive to growth suppression signals
2) Limitless reproductive potential
3) Promote inflammation
4) Can invade tissues, metastasize
Oncogenes
- Expression stimulates growth and cell division
- Regulation loss leads to extreme expression of these proteins
i.e Gas pedal on a car
Tumor Suppressors
- inhibit/check cell division
- Loss of reg leads to cell growth
i.e brakes on a car
Oncogene dominance
A single copy of the gene, rather than two, is necessary for growth training expression —- REAALLLLY BAD and why cancer sucks
Oncogene forms
1) Cellular proto-oncogenes (captured by retroviruses)
2) Virus-specific oncogenes (behave like cell proto-onco that are mutated)
3) Cellular porto-oncogenes that are mutated
What is a proto-oncogene
A normal gene that, when mutated, becomes and oncogene that can contribute to cancer
Viral Oncogenes Types
1) Transducing viruses
2) Non-transducing viruses
3) Non-transducing long-latency viruses
4) Retroviruses that contain a signaling envelope
Transducing viruses
Carries oncogene in retrovirus
Non-transducing viruses
oncogene activated by proviral insertion
Non-transducing long-latency viruses
Retrovirus protein that disrupts normal cell transcription regulation
Retroviruses that contain a signaling envelope
Viral envelop interacts with cell receptor, signaling proliferation