Neoplasia I (.Doc + .ppt) Flashcards
5 adjectives that describe neoplasms:
in order of importance
- autonomous
- irreversible (once you go autonomous you never go back)
- clonal (from a single cell gone baaad)
- Benign (or)
- Malignant
Benign or Malignant?
Commonly causes destruction of surrounding tissue
malignant
Benign or Malignant?
Cohesive, expansile local growth
benign
Benign or Malignant?
Progessively infiltrative, local growth
Malignant
Benign or Malignant?
Commonly has a fibrous capsule
benign
Benign or Malignant?
Rounded margins
benign
Benign or Malignant?
Metastasis
malignant
What is metastasis?
Secondary site of tumor discontinuous with the primary site
3 patterns of metastatic spread:
Lymphatic (to regional lymph nodes)
Hematogenous (to lung/liver)
Seeding (body cavities or surfaces)
Type of metastasis that is typical of sarcoma:
Hematogenous
Type of metastasis that is typical of ovarian carcinoma:
Seeding
Type of metastasis that is typical of carcinomas:
Lymphatic
Malignant neoplasm of epithelial cells
CARCINOMA
Malignant neoplasm of mesenchyme-derived tissue
SARCOMA
mesenchyme = connective tissue, including bone, cartilage, blood vessels, etc.
Mixed germ cell tumor
teratoma
Neoplasm containing components of more than one germ cell layer (usually all three)
TERATOMA
layers = ectoderm, mesoderm, endoderm
Mass of mature but disorganized tissue indigenous to its site
HAMARTOMA
developmental anomaly*
Mass of normal tissue present outside its normal site
CHORISTOMA
or an “ectopic rest”
Chondroma
cartilaginous hamartoma
Macroscopic projection above mucosal surface
POLYP
Term for “on a stalk” (adj)
Pedunculated
Term for “flat, like a plateau” (adj)
Sessile
Benign epithelial neoplasm forming glands or derived from glands
ADENOMA
Lack of visible differentiation of malignant tumor cells
ANAPLASIA
What gives cells the appearance of “primitive” cells?
anaplasia
Features of anaplastic cells (3)
- Larger than normal cells
- Higher nuclear/cytoplasmic ratio
- Pleomorphic
What is different about the nuclear components of anaplastic cells?
- angulated shape
- hyperchromatism
- clumped chromatin
- mitoses (the mitosis may be abn?)
- nucleoli
Tripolar mitosis is characteristic of:
anaplasia
The inability to tell what organ you’re looking at (in Nichols’ powerpoint) implies it’s an example of:
anaplasia
2 types of dysplasia:
- congenital embryonically abnormal cell organization
2. acquired cellular atypia (usually premalignant, may/may not be reversible)
Formation of abundant fibrous stroma by some carcinomas
DESMOPLASIA
Tissue with all the cytologic (individual cell) features of malignancy without visible invasion
CARCINOMA IN SITU
Most common causes of cancer death:
- Lung
- Breast (women), Prostate (men)
- Colon
9 most common types of cancer caused by smoking
- lung (90% of them)
- mouth
- pharynx
- larynx
- esophagus
- stomach
- pancreas
- kidneys
- bladder
Obesity is the cause of ____% of cancers in men and ____% of cancers in women in the US.
14
20
6 Hallmarks of cancer:
(1) self-sufficiency in growth signals
(2) insensitivity to anti-growth signals
(3) evasion of apoptosis
(4) sustained angiogenesis
(5) limitless replicative potential
(6) the ability to invade tissue + metastasize
What do tumor suppressor genes do?
control cell proliferation
How does the number of tumor suppressor genes relate to defects?
One good tumor suppressor gene is sufficient
Thus, it takes defects in both copies to contribute 1 of the many defects necessary for neoplasia
What are oncogenes?
Genes that drive autonomous cell growth in cancer cells
“Genes that apply brakes to cell proliferation”
TUMOR SUPPRESSOR GENES
RB genes are a type of ____ ______ genes
tumor suppressor
How does phosphorylated RB gene affect the cell? What phorphorylates it?
releases/allows transcription factor E2F to initiate cell proliferation
Phosphorylated by cyclins
How does dephosphorylated RB gene affect the cell?
prevents cell proliferation by binding up transcription factor E2F
What stage of the cell cycle can be blocked by RB protein (gene product)?
G1
What causes retinoblastomas in infants?
Retinoblastomas occur when a SECOND gene is defective in an infant who already has one defective copy of RB gene
(the 1st defective copy can be familial or de novo)
What is the function of APC tumor suppressor gene?
controls intestinal stem cell proliferation by WNT signaling
What is the function of APC gene product?
Breaks down beta-catenin so it can’t bind TCF (transcription factor that drive cell prolif)
APC mutations are present in ____% of colon cancers with familial adenomatous polyposis and ____% of sporadic colon cancers.
100
70
What is the function of p53?
prevents propagation of genetically damaged cells
- binds to DNA -> arrests cell cycle for repair
OR - initiates apoptosis if repair impossible
p53 has a (long/short) half life, and its activity is ended by:
short (~20 min)
ubiquitin proteolysis
p53 resistance is mediated by: (2)
- increased MDM2 (destroys p53)
2. E6 protein of HPV (degrades p53)
In _____% of tumors, biallelic loss of p53 is present
70
T/F: Hypoxia activates p53
T
Mutated NF-1 and -2) gene causes:
neurofibromatosis type 1
What function does NF-1 gene product serve in cells?
- activates GTPase, which produces GDP
- GDP binds to cell membrane RAS and inactivates it
*RAS is involved in transduction of growth factor signals for cell prolif
Von Hippel Lindau (VHL) gene product causes:
ubiquitination/degradation of hypoxia inducible transcription factor-1
(TF-1 causes increased PDGF/VEGF and tumor angiogenesis)
What does a germline mutation of Von Hippel Lindau (VHL) gene cause?
- kidney cancer
- pheochromocytoma (adrenal medulla tumor)
- retinal angioma
(with second hit mutations)
HER2, C-MYC, L-MYC and K-RAS are examples of:
oncogenes
What function does HER2 serve in cells?
EGFR receptor
What is the result of HER2 mutations?
EGFR receptor overexpressed
HER2 mutations are present in ____% breast cancers, and can be treated by:
20
blocking with antibodies
Diagnosis of a HER2 mutation?
Gene product (of HER2 overexpression) can be:
- stained
- FISH, look for gene amplification (>6)
(both are “on a continuum”)
What does K-RAS code for?
Cytoplasmic GTPase
GTPase –> GDP, which generates signal transduction proteins in response to growth factor binding EGFR.
(This induces proliferation)
What is the result of mutated K-RAS?
Increased cell proliferation (K-RAS works without the EGFR signal)
Why don’t extracellular therapies work if K-RAS is mutated?
The mutation causes proliferation in the ABSENCE of growth factor binding EGFR, which is an upstream signal
T?F: A single nucleotide substitution can cause a K-RAS mutation capable of causing cancer.
T
Tissue with all the cytologic (individual cell) features of malignancy without visible invasion
Carcinoma in situ
This initiates cell repair or suicide.
p53
A neoplasm is considered malignant when it is _______ or _______.
invading or metastasizing
T/F: A polyp will be on a stalk, never against the mucosal/epidermal surface.
F
(If a polyp is on a stalk, it is referred to as pedunculated. If it is flat, like a plateau, it is referred to as sessile. )
Disordered growth
dysplasia
Acquired dysplasia of glandular epithelium
“atypical hyperplasia” or “atypical adenomatous hyperplasia”
Why have # deaths from cancer been dropping since the 90’s?
Improvements in treatment of the 4 most common types
Most cancer deaths occur between the ages of __ and __
55
75
Causes of cancer: (7)
smoking** obesity* alcohol diet human papilloma virus (HPV) ultraviolet light asbestos
_____________ mutation or malfunction is like having faulty brakes, but _______ are like having the accelerator stuck to the floor
- Tumor suppressor gene
- oncogenes (mutations?)
Neoplasia usually accumulates multiple mutations before becoming:
a benign tumor
Why do most cancers occur in patients over 55?
the mutations needed to create a malignant tumor usually take decades
Oncogenes are mutated:
proto-oncogenes
It takes _____ bad tumor suppressor genes before theres a problem, and takes ______ bad onocogenes before theres a problem.
- 2
- 1
TP53 is one of the most commonly mutated genes in neoplasia. This is a problem because it encodes:
p53
T/F: p53 is generated in short bursts.
F: continually generated
What mediates a tumor’s response to radiation therapy?
p53
Tumor suppressor gene important in cancers of the endometrium and brain
PTEN
TGF-beta pathway mutations are important in _________ carcinomas.
pancreatic
Important in carcinomas of esophagus, colon and other sites
cadherins
KLF6 is influential in ____ cancers
prostate
Patched (PTCH) is important in:
basal cell carcinoma of the skin
K-RAS is active in some carcinomas of: (3)
colon, lung and pancreas
L-MYC is important in some
small cell carcinomas of lung
C-MYC is present in:
Burkitt lymphoma
Monoclonal antibody called trastuzumab, lapatinib and pertuzumab treat:
HER2-related breast cancers
HER2 is on chromosome:
17
A positive FISH is diagnosed by a HER2/CEP17 ratio of:
2.2 (sorry, this is stupid-specific)
T/F: EGFR blocker cetuximab is an excellent therapy for metastatic colon cancers with KRAS mutation.
F: tumors with KRAS mutation are unresponsive