Ch 12 Cancer biology McCance – Flashcards
Unlock all answers in this set
Unlock answersquestion
lipoma
answer
benign tumor of fat cells
question
sacroma
answer
malignant tumor arising from connective tissue
question
carcinoma
answer
malignant tumor arising from epithelial tissue
question
osteogenic sarcoma
answer
malignant bone tumor
question
rhabdomyoma
answer
benign tumor of skeletal muscle
question
liposarcoma
answer
malignant tumor of fat cells
question
adenocarcinoma
answer
malignant tumor of glandular epithelium
question
leimyoma
answer
benign tumor of smooth muscle
question
hepatocellular carcinoma
answer
primary liver ca
question
rhabdomyosarcoma
answer
malignant tumor of skeletal muscle
question
cancer stem cells in tumor survive
answer
cytotoxic chemo, tumor is likely to regrow
question
progression from benign polyp
answer
to malignant tumor requires multiple mutations
question
normal pro-oncogene ras becomes
answer
oncogene ras when mutation makes RAS protein active all the time
question
malignant tumors in intestines
answer
commonly mets to liver
question
different ca cells from same tumor can mets
answer
to different location because tumors are heterogenous in their cellular composition
question
presence of O2
answer
nml cells metabolize by oxidative phosphorylation & ca cells metabolize it by glycolysis
question
cell to become cancerous
answer
stepwise changes must occur in its genes
question
chronic inflammation
answer
predisposes to develop ca
question
anaplastic
answer
no cellular differentiation
question
tumor
answer
abn growth results from uncontrolled proliferation
question
transformation
answer
process by which nml cell becomes ca cell
question
neoplasm
answer
new growth
question
pleomorphic
answer
having variable size & shape
question
differentiation
answer
process by which cell develops specialized organization & function
question
examples of pro-cancer effect
answer
- point mutation inactivates one tumor suppressor gene allele, epigenetic change silences other - chromosome translocation creates Philadelphia chromosome - decreased expression of specific noncoding RNA causes increased expression of oncogenes - gene amplification creates multiple copies of genes for epidermal growth factor receptor - DNA methylation occurs in promoter regions of both copies of tumor suppressor gene - mutation disrupts caretaker gene - chromosome instability causes loss of both copies of tumor suppression genes
question
anti- cancer effect example
answer
- point mutation inactivates proto-oncogene - epigenetic modification silences oncogene
question
how carcinoma mets through blood
answer
1) mutation enable self-renewal, anchorage independence, increased motility & secretion of proteases 2) tumor microenvironment drives cell dedifferentiation by epithelial-to-mesenchymal transition 3) ca cells intravasate, facilitated by leaky blood vessels created through angiogenesis 4) ca cells circulate, evading immune system by associating w/ platelets or other mechanism 5) ca cells attach to endothelium, attracted by tissue specific characteristics & survival signals 6) ca cells extravasate, facilitated by their motility characteristics & vascular remodeling 7) ca cell secrete chemical signals that co-opt local & circulating cells, creating new cancerized microenvironment where they proliferate
question
benign tumors
answer
- well differentiated cell appearance - slow rate of growth - low mitotic index - has a capsule - slight vascularization - expansile growth - cant metastasize
question
malignant tumors
answer
- poorly differentiated cell appearance - rapid growth rate - high mitotic index - no capsule - neovascularization through angiogenesis - invasive growth - can metastasize
question
TNM
answer
Tumor (size & extent of tumor) Nodes (lymph node involvement) Metastases (extent of distant metastases)
question
assigning TNM
answer
stages ca
question
woman breast ca w/ mets to lungs, invaded chest wall & several fixed lymph nodes
answer
T3 N2 M1
question
proto-oncogene
answer
- nml gene that codes for proteins that stimulate cell proliferation appropriately
question
oncogene
answer
proto-oncogene that mutated in such way that proteins are inappropriately active accelerating cell proliferation
question
tumor suppressor gene
answer
codes for proteins that suppress cell proliferation
question
stem cell & cancer cells
answer
able to divide indefinitely because they make enzyme telomerase
question
tumors stimulate formation of
answer
new blood vessels by secreting angiogenic factors
question
abn premalignant growth in epithelial tissues
answer
that have crossed basement membrane are called carcinoma in situ
question
cancer predisposing genetic events that occur
answer
in somatic cells are not inherited but those that occur in germline cell are inherited
question
ca cell that
answer
secretes growth factor that stimulate its own growth engages in autocrine stimulation
question
characteristics of ca cells that enable them to
answer
survive & proliferate include loss of contact inhibition, resistance to apoptosis & anchorage independence
question
survival of malignant tumors is
answer
facilitated by tumor-associated macrophages that secrete cytokines & other factors that assist ca cell survival & proliferation
question
immune system
answer
important in protecting against ca caused by specific viral infection
question
carcinomas
answer
arise from epithelial tissues
question
leukemias
answer
ca of blood forming cells
question
CIS
answer
refers to preinvasive epithelial tumors of glandular or squamous cell origin
question
localize ca
answer
considered low stage
question
ca thats spread regionally & distantly
answer
stage 3 & stage 4
question
ca cells
answer
characterized by anaplasia or loss of differentiation & autonomy or independence from normal cellular controls
question
undifferentiated cells not committed to specific function
answer
known as pluripotent cells, precursor cell or adults stem cell
question
cancerous growth
answer
depends on derangement of cell differentiation
question
tumor markers
answer
- substances like hormones, enzymes, genes, antigens, antibodies) found in ca cells & in blood, spinal fluid or urine - used to screen & identify individuals at high risk for ca - help diagnose specific types of tumors - follow clinical course of ca
question
genetic events
answer
primary basis of carcinogenesis
question
mutations in cancer-causing genes accumulate
answer
w/ age causing increasing risk of ca w/ advanced age
question
mutations
answer
- activate growth promotion pathways - block antigrowth - prevent apoptosis - turn on telomerase & new blood vessel growth - allow tissue invasion & distant metastasis
question
rare families, ca is
answer
inherited in autosomal dominant fashion as result of mutations in tumor suppressor genes like TP53, RB1 & BRAC1
question
proto-oncogenes
answer
encode growth factors (PDGF0 growth factor receptors (HER2) signal transducers (RAS) nuclear growth-promoting proteins (MYC)
question
3 key genetic mechanisms have role in human carcinogenesis
answer
1) activation of proto-oncogenes resulting in hyperactivity of growth-related gene products called oncogenes 2) mutation of genes resulting in loss or inactivity of gene products that normally would inhibit growth (called tumor suppressor genes) 3) mutation of genes resulting in overexpression of products that prevent nml cell death, or apoptosis thus allowing continued growth of tumors
question
tumor suppressor genes encode for proteins
answer
- that act as inhibitors of growth factor stimulation - block specific phases of cell cycle - induce end stage (terminal) differentiation - stimulate cell senescence or death
question
carcinogenesis or development of ca
answer
involves both inactivation of tumor suppressor genes usually by loss of heterzygosity or by silencing & activation of oncogenes
question
epigenetic changes in genes by
answer
DNA methylation & covalent histone modification can mimic mutation by heritably inactivating tumor suppressor genes
question
caretaker genes
answer
responsible for maintaining genomic integrity inherited mutations can disrupts caretaker genes & cause chromosome instability
question
human cervical ca
answer
causes by papillomavirus
question
Kaposi sarcoma
answer
caused by infection w/ HHV 8 or member of Herpesviridea family
question
chronic hepatitis infection w/ HBV or HCV
answer
leading cause of liver ca
question
chronic H pylori
answer
associated inflammation causes stomach ca
question
human papillomavirus
answer
cause cervical ca
question
carcinomas undergo process of epithelial transition (EMT) during which
answer
many epithelial like characteristics are lost (ex polarity, adhesion to basement membrane) resulting in increased migratory capacity, increased resistance to apoptosis & dedifferentiation to stem cell like state that favors growth in foreign microenvironments & establishment of metastatic disease
question
clinical manifestations of ca
answer
fatigue pain cachexia anemia leukopenia thrombocytopenia infection
question
paraneoplastic sndromes
answer
rare caused by release of active substances from or stimulation of immune response by ca that causes sx not directly produced by local effects of ca
question
pain
answer
associated w/ late stage ca caused by pressure, obstruction, invasion of structure sensitive to pain, stretching, tissue destruction & inflammation
question
fatigue
answer
most frequently reported
question
cachexia
answer
loss apetite, early satiety, weakness, inability to maintain wt, taste alterations, AMS) leads to protein calorie malnutrition & progressive wasting
question
anemia
answer
associated w/ ca usually occurs because of malnutrition, resultant iron deficiency, chemotherapy, radiation & malignancies in blood forming organs
question
leukopenia
answer
- results of chemo which is toxic to bone marrow or radiation
question
infection
answer
may cause by leukopenia, immunosuppressed or debility associated w/ advanced disease
question
catecholamines
answer
marker used tumor of adrenal glands
