Term
| What are the 8 primary features of malignant transformation? |
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Definition
AIR DREAM
1) Autonomy (from external growth signals)
2) Invasion (and metastasis) using enzymes to digest and migrate
3) Resistance (to growth inhibition)
4) DNA repair defects
5) Replication (without end)
6) Evasion (of apoptosis)
7) Angiogenesis (only 2mm without it)
8) Means of escape from host immunity and rejection |
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Term
| How do oncogenes promote malignant transformation? |
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Definition
- mutations in "proto-oncogenes" cause genes to produce products that do work of causing cells to grow and divide
- Only 1 couple of the gene is needed
- Can be Growth Factors (FGF3), GF receptors (EGFR), Signal transduction proteins (RAS), t-factors (MYC), cell-cycle regulators (Cyclin-D1) |
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Term
How do tumor suppressor genes suppress and promote malignant transformations?
What are some examples? |
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Definition
1) Normally, they are growth-inhibitory genes.
2) Multiple genes form network of "checkpoints"
3) BOTH copies must be lost for neoplasia to result
4)
- APC- inhibits signal transduction to prevent colon cancer
- p53 arrests cell cycle
- Rb1 involved in retinoblastoma
- BRCA1 and BRCA2 in DNA repair in breast, ovarian and other cancers. |
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Term
| Explain how "initiation" and "promotion" work in chemical carcinogenesis. |
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Definition
1) Initiation occurs when alterations are made to DNA by direct or indirect initiator molecules (they have to be permanent changes in order to propagate). Most are indirect, and require metabolic conversion.
2) Promoter elements propagate the initiating mutation by causing increased cell division
Examples are Pesticides, Alkylating Agents an Nitrosamines. |
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Term
| Provide an example of Microbial carcinogenesis |
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Definition
1) Viruses can act as "portable oncogenes"
2) Helicobacter pylori (causes ulcers in stomach and duodenum) can cause metaplasia and lead to Lymphoma and gastric adenocarcinoma. |
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Term
| What is the "adeno-carcinoma" sequence? |
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Definition
| The idea that the phenotype of tissues changes as it acquires more and more genetic damage, and that each damage pre-disposes to further damage. |
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Term
Explain how the UICC (TNM) system of assessing tumor stage.
What does pT2a N1 M1 mean?
How does the TNM system differ from AJC? |
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Definition
1) Give numbers to T (tumor), N (lymph nodes), and M (metastasis)
2) A "pathological" Tumor (between 3 and 5cm), found only in the intrapulmonary peribronchial lymph nodes (N1), that has also been found in a distant site (M1)
3) AJC integrates the TNM stages into a single stage from 1-4 (above would be 4, and 2a if it had no metastasis) |
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Term
| What is the most common tumor of the liver? |
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Definition
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Term
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Definition
| Decreased in overall body mass resulting from metabolic demands of tumor. |
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Term
What are paraneoplastic syndromes?
Provide a few examples. |
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Definition
- Symptoms that are associated with neoplasms that cannot be explained by characteristics that are inherent to the tumors themselves.
- Occur in 10% of cancer patients
- Hypercalcemia (PTH-analog), Cushing (ACTH-analog), Carcinoid (serotonin)
Hypercalcemia (substances acting like PTH coming from tumors),
- Cushing syndrome (increased cortisol from substances acting like ACTH)
Carcinoid syndrome (skin flushing, ciarrhea from too much Serotonin release) |
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