MCP 15&16 Flashcards
Define benign
-milder, usually harmless, non-progressive disease does not metastasize
Define tumor
- overgrowth of cell material, can be solid or dispersed
- clonality - all the cells typically originate from one mutated cell line
- can be benign or malignant
describe clonal
- tumors generally start as a single cell with a mutation which proliferates to form a group of similarly abnormal cells
Define malignancy
uncontrolled cell growth characterized by a change in the normal organization pattern of tissues or cells
-karyotypic changes, metastasis
Define metastasis
when cells become invasive or migrate to another site. When they move they retain the original cell morphology. Therefore a tumor in the liver that was founded by breast cancer cells is still called breast cancer
Define cancer
-malignant tumor or potentially unlimited growth that expands locally by invasion and systemically by metastasis -> overgrowth of cell material and clonal
How is a primary cancer in a secondary location classified?
- classified by its primary location type
Name some environmental factors that affect cancer incidence
UV light, asbestos, cigarette smoke, plastics dyes, red dye #3
- cancer most likley a combination of environmental and genetic factors
Hallmarks of cancer
- mutations or loss of genes involved in cell control including growth/division, proliferation metabolism
- environmental elements may influence mutation
- mutations may be inherited or acquired
- chromosome instability (gain or loss of chromosomes)
Oncogene
-a dominantly acting gene involved in unregulated cell growth and proliferation
-carried by viruses
-associated with disease in animals
H-ras-harvey rat sarcoma
sis-simian sarcoma virus
abl-abelson murine leukemia virus
What are the oncogenes found in humans?
viral oncogenes in humans
- HPV -cervical cancer E6 and E7
- EBV- nasopharyngeal cancer, hodgkin and burkitt lymphoma
- HHV 8 - kaposi sarcoma
- HTLV -1- T cell leukemia
- HTLV-2 various leukemias
- mutation of other proto oncogenes
Define proto-oncogenes
- critically important housekeeping genes that are present throughout the human genome and in their native state are not associated with diseases
- present throughout the genome and have been mapped to nearly all chromosomes
List some of the functions of proto-oncogenes
- growth factors
- cell surface receptors
- intracellular signal transduction
- DNA binding proteins (transcription)
- regulation of cell cycle
Describe what happens when proto-oncogenes go haywire
- mutation (translocation, amplification, point mutation) can result in “activation” of a proto-oncogene
- this may change gene regulation, gene transcription or a protein product generating alterations to cell growth, proliferation or differentiation
- can lead to tumorigenesis
- gain of function mutation
- dominant - only need one mutation
what is clinically diagnostic of APL
- translocation of 15 and 17 is considered clinically diagnostic
- because of the need of hasty results FISH is generally performed first and then karyotype analysis
Tumor suppressor
- genetic element whose loss or inactivation allows the cell to display an alternate phenotype leading to neoplastic growth
- oncogenetic potential when gene activity is lose
- true recessive
Name and specify the two types of tumor suppressor gene types
gate keepers-> suppress tumors by regulating cell cycle or growth inhibition
caretakers - repair DNA damage and maintain genomic integrity -> effect is indirect via the accumulation of errors in the cells