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39 Cards in this Set
- Front
- Back
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What are the paths to cancer?
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1. Loss control of mitotic cycle (tumor)
2. Invasion of surounding tissue (malignancy) |
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what disease is connected with defective nucleotide base excision repair?
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XP
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What disease is associated with defective mismatch repair?
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heredity non polyposis colon cancer
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What disease is associated with defective double strand break repair?
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Familial breast cancer
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A thymine dimer is recognized by what protein?
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XP-C and 23B
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What does the XP-C and 23B complex recruit and what does it do?
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TFII-H has helicase activity i.e opens dsDNA
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Following XPII-H, what comes and further opens and stabalizes the dsDNA?
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XP-G and RPA
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What XP genes act as endonucleases?
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XP-G and XP-F
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Is XP characterized by Locus Heterogeneity?
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Yes -->mutations in 7 genes
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Cancer is causes by SOMATIC muations in genes that control what?
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1. cell proliferation
2. programmed cell death 3. genome stability |
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What are some gentoxic mechanisms?
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1. ionization radiation
2. chemical carcinogens |
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What are some non-genotoxic mechanisms?
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1. alcohol
2. hormones other tumor promoters |
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Is malignant transformation a multistep process?
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yes
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What is an example of Self-sufficiency of growth signals?
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Ras mutation
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What is an example of an insensitivity to anti-growth signals?
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Turn off Rb
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What is an example of evading apoptosis?
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IGF production
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What is an example of limit-less replicative potential?
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turn on telomerase
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What is an example of sustained angiogenesis?
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produce VEGF inducer
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What is an example of uncontrolled tissue invasion and metastasis?
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overactive E-Cadherin
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Which cancer genes are recessive at the cellular level?
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tumor supressors genes: require mutation on both alleles
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Which cancer genes are dominant at the cellular level?
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Oncogenes: mutation in 1 allele is enough
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What are some tumor suppressor cancers?
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1. Rb-loss of RB
2. FAP- loss of APC 3. HNPCC- MSH 4. Familial Breast Cancer- BRCA 1|BRCA 2 5. liFraumeni Syndrome- p53 loss |
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What cancers have a high contribution of hereditary factors?
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1. prostate
2. colorectal 3. breast |
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In retinoblastoma we have an insensitivity to anti-growth signals i.e loss of Rb inhibition on E2F. How is heterozygosity lost?
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1. mitotic non-disjunction
2. mitotic recombination *@ chromosome 13 |
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How is Rb that is inherited distinguished from non inherited Rb?
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inherited has bilateral tumors present
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What is the the etiology of Familial Adenomatous Polyposis?
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1. Growth Factor (WNT) causes the APC to fall off from its inhibition from Beta-Catenin that turns on TCF causing Proliferation
2. In FAP, APC is mutated and unable to destroy Beta-Catenin |
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What malignant transformations does FAP have?
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1. Self Sufficieny (no need for WNT)
2. Insensitivity to Anti-growth signals (bad APC) |
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Which has an increase in the number of polyps. FAP or HNPCC?
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FAP
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What is the etiology of HNPCC?
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1. Typically, MSH2/6 recognize mismatch repairs and MLH1 and PMS endonuclease errors
2. HNPCC has mutations in these genes |
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What malignant transformations does HNPCC have?
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Genomic Instability (bad MSH)
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What is LiFraumeni Syndrome?
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the development of many cancers
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What is the the etiology of LiFraumeni Syndrome?
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Loss of p53 which cause increase in cell proliferation and loss of apoptosis potential
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What is a dominat negative mutation in p53?
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1. p53 is a tetramer
2. Loss function in 1 subunit causes the whole protein to not work |
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What does p53 activate?
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1. Bax --> Apoptosis
2. p21 --> CDK inhibitors --> stop G1 |
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What malignant transformations does LiFraumeni Syndrome have?
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1. Genomic Instability: (DNA damage accumilation)
2. Insensitivity to Anti-growth signals: (CDK inhibitor (p27) loss) 3. Evasion of Apoptosis: (no Bax) |
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What is the etiology of Familial Breast Cancer?
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1. mutations in either BRCA 1 or BRCA 2 that normally fix Double stranded breaks in DNA
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Who does BRCA 2 derived breast cancer affect?
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Males and females
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What malignant transformations does Familial Breast Cancer have?
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Genomic Instability ( bad BRCA1/2)
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Inablity for RAD to look for homologous DNA on sister chromatids due to mutations in BRCA1/2 can lead to what?
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Other mutations will arise b/c other mechanism will try to fix the double stranded break and cause:
1. base pair loss 2. translocations |
