Neoplasia Flashcards
what are the 8 fundamental changes in cell physiology which are considered the hallmarks of cancer?*****
1) self-sufficiency in growth signals –> proliferate without external stimuli
2) evading growth suppressors
3) altered cell metabolism –> switch to aerobic glycolysis to use more energy for more growth (WARBURG)
4) Evading apoptosis
5) unlimited replication
6) inducing angiogenesis
7) ability to invade and metastasize
8) evade host immune response
What gene rearrangements revolve around the tyrosine kinase ALK receptor?
deletion on chromosome 5 fuses part of the ALK gene with another gene called EML4 –> this is in a subset of lung adenocardinoma!
What differentiates the rate of growth between benign and malignant tumors?
Benign: usually progressive and slow; may come to a standstill; mitotic figures are rare but normal if present.
Malignant: erratic, may be slow to rapid; mitotic figures may be numerous and abnormal.
What is Carcinoma in situ and what makes it different than carcinoma?
what is the best example of this
a pre-invasive neoplasm… when dysplastic changes involve the full thickness BUT DOES NOT penetrate the basement membrane.
once the tumor breaches the basement membrane, it’s “carcinoma” or invasive.
how many alleles do we have to change in proto-oncogenes to make it cancerous?
what about tumor suppressor and the promoting of neoplasms?
1
2
follicular lymphoma translocation?
(14;18)(q32;q21)
most carcinogens are metabolized by what?
cytochrome P-450 dependent mono-oxygenases
On the worldwide distribution of prostate and breast, where is it most frequent?
what are the reasons for the differing incidences? (6 things)
developed countries have the highest levels of people suffering from these
1) infectious disease
2) smoking + alcohol consumption
3) Diet
4) obesity
5) reproductive history (exposure to estrogen stimulation)
6) environmental carcinogens
When might you see migratory thrombophlebitis?
(trousseau syndrome) –> encountered with deep-seated cancers, most often carcinomas of the pancreas or lung.
What is the one unequivocal criterion of malignancy? what is its definition?
Metastasis… benign do NOT metastasize.
spread of a tumor to sites that are PHYSICALLY DISCONTINUOUS with the primary tumor.
ERBB1 problems are found in a subset of what cancer? how is it happening?
what about ERBB2? what does it encode and what happens?
lung adenocarcinomas –> POINT MUTATIONS lead to constitutive activation of EGFR tyrosine kinase (since ERBB1 encodes it)
Encodes HER2 –> breast carcinomas –> AMPLIFICATION (not mutations) leading to over expression of HER2 receptor and constitutive tyrosine kinase activity
What is TP53?
GUARDIAN OF THE GENOME
it’s a tumor suppressor protein that regulates cell cycle progression, DNA repair, cellular senescence, apoptosis
MOST FREQUENT MUTATED GENE IN HUMAN CANCER
why are benign tumors generally considered well-differentiated? (2 things)
how do we know a benign tumor of a endocrine gland is well-differentiation and what’s the implication behind this?
How does this differentiate from anaplastic tumors?
pretty much retains its functional ability
1) it so easily resembles the normal tissue that it can be impossible to recognize it as a neoplasm.
2) mitoses are rare and usually are of normal configuration
– they secrete hormones characteristic of their origins, so we would see increased levels of hormones in the blood.
***anaplastic tumors will instead have new and unanticipated functions
TP53 is found where?
17p13.1
Asbestos:
1) what types of human cancers are associated with this?
2) when might someone be exposed to this?
lung, esophageal, gastric, and colon carcinoma; mesothelioma
used to be part of fire, heat, and friction resistant materials. underlayment and roofing papers/roof tiles.
NF2
1) what does it encode?
2) lack of this product means what?
3) what disease is a complication?
creates neurofibromin 2 or MERLIN
lacking merlin means no stable cell-to-cell junctions, and are insensitive to normal growth arrest signals generated by cell-to-cell contact
neurofibromatosis type 2
What’s said to cause the induction of cutaneous cancers?
why is this carcinogenic?
nonmelanoma vs melanoma?
UVB light
it forms pyrimidine dimers
total cumulative exposure to UV –> nonmelanoma (low and slow exposure)
intense intermittent exposure –> melanoma (high and fast exposure)
What is tumor differentiation?
what if there is lack of differentiation? what does this mean?
what tumor is considered to have this lack of differentiation, typically?
extent to which neoplastic PARENCHYMAL cells resemble the corresponding NORMAL parenchymal cell morphologically and functionally.
this is called anaplasia –> “to form backward” implying a reversal of differentiation to a more primitive level.
malignant neoplasms are considered to be anaplastic in nature.
Hypercalcemia can be seen in what cancers?
squamous cell carcinoma of the lung.
what is a promoter?
what are indirect-acting carcinogens? what’s the product called?
what’s an example?
chemical agents that increase in proliferation, but that are not mutagenic UNLESS an initiator has screwed up the DNA.
these REQUIRE metabolic conversion to become active –> called an “ULTIMATE CARCINOGEN”
Polycyclic hydrocarbons
Radon
1) what types of human cancers are associated with this?
2) when might someone be exposed to this?
Lung carcinoma
decay of mineral containing uranium; quarries and underground mines
What’s to note about genetic predispositions and the relevance of inherited factors and environmental factors in neoplasia?
include 2 diseases
well defined inherited components that lead to cancer can be greatly influenced by non genetic factors
ex) breast cancer (BRCA1 and BRCA2) –> enhanced 3x after 1940 because change in reproductive history
strongly environmental diseases can conversely be upregulated by genetic problems
ex) cytochrome p-450 problem’s increases susceptibility in lung cancer caused by smoking.
What is metaplasia?
what is dysplasia? what features can you see that tell it’s not metaplasia?
what features of anaplasticity can be seen in dysplasia?
replacement of one type of cell with another type, often in association with tissue damage, repair, regeneration. –> the replacement is always better suited for the new environment.
“disordered growth” –> metaplasia that has gone awry… loss of uniformity, loss of architectural orientation.
pleomorphism, abnormal nuclear morphology (1:1 cytoplasm:nucleus), mitotic figures
Arsenic and arsenic compounds:
1) what types of human cancers are associated with this?
2) when might someone be exposed to this?
Lung carcinoma + skin carcinoma
metal smelting, food and water contamination