Exam 3 Objectives Flashcards
Define neoplasm
New growth (abnormal).
Neoplastic cells continue to replicate unaffected by controls of the cell cycle.
Tend to increase in size regardless of their local environment.
Disorderly cell proliferation, differentiation, and relationship to the surrounding stroma.
Depend on the host for their nutrition and blood supply.
Define tumor
A neoplasm.
Can be malignant or benign.
Malignant is cancerous - the lesion can invade and destroy adjacent structures and spread to distant sites (metastasize) to cause death.
Benign - remains local and relatively innocent.
Define carcinogenesis
Cells in a tumor can be caused be genetic mutations that are induced by environmental insult such as chemicals, radiation, or viruses.
Define oncology
Study of tumors.
Oncos = tumor
Logos = study of
Discuss the fundamental characteristics of all cancers
A genetic disorder caused by DNA mutations that can be spontaneous or induced.
Frequently show epigenetic changes.
Altered expression or function of key genes that regulate fundamental cellular processes such as growth, survival, and senescence.
Assess wether a neoplasm change is benign or malignant using all of the proper criteria
Benign: Doesn't invade surrounding tissue No metastasis Growth rate is low Little mitosis Some atrophy of surrounding tissue by pressure of the mass
Malignant: Invades surrounding tissues - invasive Metastasis Lots of mitosis and growth - increased proliferation Damages surrounding tissue Abnormal tissue formation Incomplete differentiation
Describe the morphologic changes associated with anaplasia
Lack of differentiation.
Backward formation - loss of the structural and functional differentiation of normal cells.
Often cells remain “stuck” in more immature states. The more immature, the worse the outcome.
Immature, undifferentiated cells exhibit behaviors, that they sounds’t, like expressing fetal proteins or hormones.
Compare and contrast metastatic neoplasm with dysplasia
Dysplasia: cell changes indicative of malignancy but no invasion present yet. It is a warning sig. Common in epithelial tissues.
If the whole depth of the tissue is dysplasia, then the term carcinoma in situ is used.
Metastatic neoplasm has invades other tissues and spreads from origin to other parts of the body.
Compare and contrast papillomas and adenomas
Papilloma:
Epithelial cells growing in a sheet
Squamous, transitional or columnar
Adenoma: Solid islands or masses of cells Arising from gland or duct epithelium Small groups of cells gather around a lumen No real drainage - cyst may develop
Compare and contrast carcinoma and sarcoma
Carcinoma:
Malignant
From epithelial cells
Sarcoma: Type of carcinoma Malignant Arising in "solid" mesenchymal tissues Designated by the cell type they are composed of (cell or origin)
Contrast neoplastic differentiation defects with metaplasia
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Compare and contrast normal cell adaptations to stress to neoplastic growth
Non-neoplastic changes cease when stimulus is removed
Neoplastic changes don’t respond to normal stimulus - autonomous behavior
Discuss physiological negative feedback loops
Non-neoplastic changes cease when stimulus is removed
Neoplastic changes don’t respond to normal stimulus - autonomous behavior
Hyperplasia:
A response to an increase in functional need
Controlled by negative feedback mechanisms
Congenital hyperplasia:
Defective adrenal cells cause decrease in cortisol and aldosterone.
Increased adrenocorticopic hormone from pituitary.
Made more adrenal cells which still don’t work. Buildup precursors of hormones get used for steroid production instead.
Example of negative feedback not working.
Name the enzyme groups which control the cell cycle
Cyclins: regulate progression through the cell cycle Cyclin dependent kinases (CDKs): activated by binding to cyclins, maintain orderly progression CDK inhibitors (CDKIs): broad and selective inhibitors of CDKs
List the hallmarks of cancer and discuss the genetic alterations that occur in each
- Self-sufficiency in growth signals
* Cancer cells overexpress growth factor receptors
* Can have receptors that are always on - don’t need GF
* Over expression of EGF
* Signal transducing proteins: RAS and ABL
* Nuclear transcription factor: MYC
* Cyclins, CDKs (increased), CDKIs (decreased or inhibited) - Insensitivity to growth inhibitory signals
* Tumor suppressor genes
* RB (the governor), TP53 (the guardian), TGF-beta, Contact inhibition pathways
* Something is wrong with one of these signals and cells grow out of control
* Cadherins: mediate cell-to-cell contact - Evasion of cell death
* BAX-BAK pro-apoptotic
* BCL2 anti-apoptotic
* Avoid autophagy - Limitless replicative potential
* Telomerase
* Ends of chromosomes get connected - Development of sustained angiogenesis
* VEGF, HIF-1alpha, VHL, FGF, ECM - Ability to invade and metastasize
Discuss how each of the hallmarks of cancer contributes to the phenotype of cancer cells
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Describe the three types of spread of tumors within the body
Seeding within body cavities
Lymphatic spread
Hematogenous spread
List and describe the steps that occur in metastasis
- Liberation from the first tumor
- Invasion of surrounding tissues to get to a transfer tubing
- Adhere to the basement membrane of the blood vessel
- Transfer in tubing as an emboli
- Adhesion at endothelium
- Migration from the vessel
- Survival (angiogenesis)
- Multiplication and growth of new tumor much like the original
Link the processes which are required for invasion to the characteristics of a metastatic tumor that contributes to its invasion
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Explain how most cancers result from monoclonal expansion but can then become more aggressive and resistant to treatment overtime
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List and describe the function of the four classes of normal regulatory genes which are the primary targets of genetic damage leading to neoplastic changes
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Describe the two types of tumor suppressor genes
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Describe the types of chromosomal lesions that can be observed in tumor cells
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Explain how epigenetic changes and microRNA mutations can be involved in neoplastic transformation
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List the five factors that contribute to an individual’s risk of developing cancer
- Geographic and environmental variable - sun exposure
- Age - older people tend to have a higher risk
- Heredity - specific alleles, mutations, etc.
- Diseases - chronic inflammation
- Immunosuppressed
List the categories of carcinogenic agents
Direct-Acting Agents
Require no metabolic conversion to become carcinogenic
Can be used as a treatment of cancer and cause another form of cancer (usually leukemia)
Indirect-Acting Agents
Require metabolic conversion
Radiation
Chromosomal breakage
Translocations
Microbial and Viral
Contrast direct-acting chemical carcinogens with indirect-acting agents
Direct-acting does not need a metabolic change to cause damage like indirect-acting agents do.
Direct-acting is very hard on the body
Describe two theories of radiation and carcinogenesis
Direct: radiation itself damages DNA
Indirect: radiation activates dormant viral oncogenes
Type of cancer associated with HPV
Warts and cervical cancer
Interactions with Rb and p53 released transcription factors normally sequestered
Type of cancer associated with EBV
Burkitt’s lymphoma and many others
Attaches to B cells through CD21
Causes proliferation and generation of lymph-blastoid cell lines