genes and cancer
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Genes and Cancer. What is cancer?. Uncontrolled cell growth Ability to spread to other parts of the body Generally a disease of aging Tumors are named according to the tissue from which they form Benign (do not spread) Malignant (can metastasize). Is cancer genetic?. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/1.jpg)
Genes and Cancer
![Page 2: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/2.jpg)
What is cancer?
• Uncontrolled cell growth• Ability to spread to other parts of the body• Generally a disease of aging• Tumors are named according to the tissue
from which they form– Benign (do not spread)– Malignant (can metastasize)
![Page 3: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/3.jpg)
Is cancer genetic?
• “Predisposition” can be inherited• Most mutagens are carcinogens• Cancer genes can be spread by viruses• Some cancers are know to be cause by
chromosome abnormalities• Most cancers are sporadic (not inherited)• Cancers are caused by damage to DNA
(mutation)
![Page 4: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/4.jpg)
Trialx.com
Nature.com
Metastasis
![Page 5: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/5.jpg)
First mutation Secondmutation
![Page 6: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/6.jpg)
The cell cycle and regulation• Cell division usually closely
regulated• Checkpoints control
transition through stages– Tumor suppressor genes– Proto-oncogenes
• Triggered by signal transduction
• Loss of control leads to tumor formation
![Page 7: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/7.jpg)
Bio.miami.com
Model of cell activation
![Page 8: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/8.jpg)
Mutations in regulatory genes implicated in cancer
• RB1- tumor suppressor , controls progression from G1 to S
• Ras proto-oncogenes: mutants are always switched on
![Page 9: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/9.jpg)
Nature.com
Wormbook.org
Ras proteins mutated atAa 12 or 61
![Page 10: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/10.jpg)
Genomic stability and hereditary cancer
• BRCA 1 and BRCA 2 (breast, ovary prostate)• more information• p53: whether cell is repaired or undergoes apoptosis• Abl- proto-oncogene, white blood cells• Some genes are widely distribute; some restricted to
specific tissues
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Multistep model for colon cancer
APC K-ras DCC
p53
p53 implicated in about half of all cancers
![Page 12: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/12.jpg)
Li- Fraumeni syndrome: a mutation in p53
![Page 13: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/13.jpg)
Inheritance of von Hippel-Lindau syndrome
![Page 14: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/14.jpg)
www.nobelprize.org
Chromosomal translocations- hereditary cancer
Found in several leukemiasAnd lymphomas
Burkitt’s lymphoma
![Page 15: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/15.jpg)
What causes cancer?
• Minority of cancers are inherited• Environmental factors
– Carcinogens– Viruses– Diet– Etc.
![Page 16: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/16.jpg)
How do we study causes of cancer?
• Population studies• Case-control studies• Prospective studies
![Page 17: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/17.jpg)
Treatment strategiesExample: breast cancer
strategy• Removal
• Match phenotype to treatment
• Use genotype to select drug
example• Surgery, radiation,
chemotherapy• Target estrogen receptor if
present• Depends on presence of
cancer-specific gene• Microarrays make rapid
diagnosis possible
![Page 18: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/18.jpg)
Summary
• Cancer is caused by genetic mutation, but is usually not inherited
• Tumor cells divide uncontrollably• Tumors can arise in a variety of cells• Proto-oncogenes, tumor suppressor genes,
and DNA repair genes are implicated in cancer• Cancers can arise from two or more mutations
![Page 19: Genes and Cancer](https://reader036.vdocument.in/reader036/viewer/2022062501/568160df550346895dd00d8e/html5/thumbnails/19.jpg)
• Population studies in conjunction with biochemical and genetic studies can help explain causes of cancer
• Molecular and genomic studies are used to develop treatments that are specific to the type of tumor.