Term
| Where do cancer cells derive from? |
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Definition
| single cell, forming a neoplasm, or tumor |
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Term
| What are the two types of tumors? |
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Definition
Benign: noninvasive
malignant: can invade and spread (metastasis) |
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Term
| How are cancers classified? |
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Definition
By their origin
- Carcinomas- skin, organ, glands
- leukemias and lyphomas- bone marrow cells
- sacromas- bone, fat, cartilage |
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Term
| What are the general stages of becoming a malignant tumor? |
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Definition
a) initially modified tumor cell
b) mass of tumor cells (localized benign tumor)
c) invasive tumor cells
d) tumor cells invade blood vessels, allowing metastasis to occur |
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Term
| How do healthy cells become transformed into malignant cells? |
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Definition
- radiation
- carcinogens
- pathogens - viruses and bacteria |
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Term
What are the three types of regulatory genes?
What happens if there is a defect in any of them? |
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Definition
1. proto-oncogenes: induced proliferation in various ways
2. tumor suppresors: inhibit cell proliferation
3. Regulators of apoptosis
Defect of any of the above will cause uncontrollable cell growth |
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Term
Name the following
a. growth factor
b. signal transducers
c. transcription factors
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Definition
a. sis- form of platelet growth factor
b. src; tyrosin kinase. N-ras and K-ras are both GTP-binding protein w/ GTPase activity
c. p53; nuclear phosphoprotein that inhibits formation of small-cell lung cancer and colon cancers. |
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Term
| What do proto-oncogenes on normal cells normally express? |
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Definition
essential grwoth-controlling proteins
- growth factors
- growth factor receptors
- signal transducers
- intranuclear factors
- regulators of programmed cell death
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Term
| When proto-oncogenes undergo retroviral transduction, what happens? |
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Definition
| transformed cells via viral oncogenes |
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Term
| What is the philadelphia chromosome? |
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Definition
| Cancer is caused when there is a switch on genes from 9 to 9 q+ and 22 to 22q-. |
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Term
| Explain the mechanism of how a normal epithelium would become metastasis? |
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Definition
- Normal epithelium gets loss of APC than it becomes hyperproliferative.
- DNA hypomethylation than begins early adenoma
- K-Ras becomes activated than intermediate adenoma
- loss of DCC goes into late adenoma
- loss of P53 leading to a carcinoma
- other alterations will then lead to metastasis
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Term
| What is unique or "not unique" about Burkitt's syndrome? |
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Definition
Most patients w/ this cancer has the c-myc gene translocated to the Ig heavy-chain gene cluster on chromosome 14.
What is unique is that the c-myc gene can be either
- entire gene can be near heavy chain
- only coding exons (2 and 3) of of c-myc are inserted in S mieu switch site |
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Term
| Where are tumor-specific antigens (TSA) found? |
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Definition
only on tumor chemical or physical carcinogens, some viruses (ATLL, HPV)
- adult t cell leukemia/lymphoma
- human papilloma virus (types 16 + 18) |
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Term
| What are tumor-associated antigens (TAA)? |
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Definition
| Gene products that are not normaly expressed (or at the abnormal levels seen in cancer) |
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Term
| What are the two methods used to isolated tumor antigens that induce tumor-specific CTLs? |
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Definition
1) make a malignant tumor. Elude the MHC peptide (b/c they express different antigens); due to down regulation from MHC and/or expression of chemokines so our immune cells aren't picking up that malignant tumor is wrong. Make peptides and purify HPLC and then sequence the peptides to see if it is a melanoma or not.
2) cDNA library. There is a tumor cell cDNA library, make a plasmid to the DNA and introduce it to the cell to get replication |
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Term
| Why do well-developed countries have more cancers? |
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Definition
a) live longer
b) active screening
c) diet
d) pollution |
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Term
| Explain the results of the experiment with the mouses used to develop tumor |
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Definition
Discovered that when the mouse is exposed to a recombinant pv tumor antigen or vaccinia virus vectoc-pv tumor antigen or CTLs with a live pv-induced tumor cells that they would not develop the tumor.
An unimmunized mouse would develop a tumor with injection of live pv-induced tumor cells |
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Term
| What is found during cancer with fetal proteins? |
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Definition
Fetal proteins decrease throughout life, but are found to increase during cancers e.g growth factors
e.g CEA: Carcinoembryoic antigen
AFP: alpha-fetoprotein
Oncogenes proteins as tumor antigens
- neutrophils on human breast cancer cells
- TATA's on human melanomas: MAGE 1, |
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Term
| Tumors reduce which class of MHC's expression? |
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Definition
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Term
| What cells can attack and kill? |
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Definition
| Macrophage and NK can attack. NK can also kill |
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Term
| How can tumors evade the immune response? |
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Definition
- anti-tumor ab can block T cell responses (enhance tumor growth)
- tumor can modulate antigens
- tumors can reduced MHC class I expression
- tumors can reduce 2nd signal expression
- no B7 -> clonal anergy
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Term
| What are some strategies for immunotherapy? |
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Definition
- make cells more immunogenic
- enhancement APC activity can modulate
a) tumor immunity
b) BGC
c) mouse dendritic cels incubated w/ GM-CSD and
tumor fragments, then into animal, activate
anti-tumor Th and CTLs |
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Term
| Explain the mechanism for the tumor destruction via CTL activation? |
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Definition
| Tumor cell transfected w/ B7 gene to activate CTL to destroy the tumor. |
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Term
| Explain the mechanism of tumor destruction with GM-CSF gene? |
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Definition
APC presents to TH which release IL-2
- IL-2 attaches to a CTL-p receptor which is also attached to the dendritic cell to destory the tumor cell with tranfected GM-SCF gene. |
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Term
| What are some cytokine therapies? |
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Definition
- attempt with inteferons (increase MHC), TNF, IL,2,4,6,12 and GM-CSF
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Term
| what are some problems with cytokine therapies? |
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Definition
a) complexity of cytokine interaction
b) harder to administer
c) short half life
d) serious side effects |
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Term
| How are Lak cells a solution? |
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Definition
- grow blood cells in high levels of IL 2
- produce mostly NK cells
- not tumor-specific |
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Term
| How are TIL (tumor infiltrating lymphocytes) used as therapy?- |
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Definition
- may have more tumor specificity activity
- need less IL-2 |
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Term
| What are some tumors that monoclonal antibodies are useful in treating? |
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Definition
1) idiotype-specific for B-cell lymphoma
2) humanized
3) anti-her2 for Her2-receptor bearing (breast cancer)
4) immunotoxins: mab conjugated to ricin |
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