Microm 445 Exam 3 With Verified
Answers
Cancer v- vCORRECT✅✅A vgroup vof vdiseases vcharacterized vby vuncontrollable
vgrowth vand vspread voof vabnormal vcells. vif vthe vspread vis vnot vcontrolled, vit vcan
vresult vin vdeath- vgroup vof vdiseases vneoplasia
Neoplasm v- vCORRECT✅✅Tumor, vnew vgrowth- vproliferation vof vcells vno vlonger
vunder vnormal vphysiologic vcontrol
Metastasis v- vCORRECT✅✅cells vfrom vthe vtumor vseed vout vto vother vparts vof vthe
vbody vand vthen vgrow vinto vtumors vthemselves
Benign vv vmalignant vtumors v- vCORRECT✅✅Benign- vdo vnot vinvade vother vtissues
vor vorgans vand vcannot vmetastasize
Malignant- vtumors vcan vinvade vand vmetastasize
Burden voof vcancer v- vCORRECT✅✅every v6th vdeath vin vthe vworld vis vfrom vcancer
About v40% vof vpeople vwill vbe vdiagnosed vwith vcancer vat vsome vpoint vin vtheir vlives
15-17% vof vall vhuman vcancers vare vcaused vby vviral vinfectioons
Relative vranking vof vcancer vincidence vvaries vin vdifferent vcountries
Seven voncogenic vviruses vof vhumans v- vCORRECT✅✅Herpesviridae- vEBV, vKaposi
vsarcoma vassociated vherpesvirus v(KSHV)
Papillomaviridae- vhuman vpapillomavirus v(HPV)
Polyomaviridae- vMerkel vcell vpolyomavirus
Hepadnaviridae- vHepatitis vB vVirus v(HBV)
Flaviviridae- vHEp vC
Retroviridae- vHuman vT vlymphotropic vvirus v1
Not va vlot vin vcommon- vnot vzoonotic
can vestablish vpersistent vinfections
,Characteristics vof voncogenic vviruses v- vCORRECT✅✅Not va vlot vin vcommon,
vtransmitted vbetween vhumans v(not vzoonotic, vcan vestablish vpersistent vinfections
These vproperties vare vnot vunique vto voncogenic vviruses
Cancer vis vnot vneeded vfor vreplication v
Viruses vhave vnot vevolved vto vcause vcancer
Cancer vis vessentially va vby-product vof vthe vaction vof vviral vproteins von vthe vcell vto
vpromote vreplication vand vtransmission
Types vof vcancer
by vlocation v
by vtissue vtype
Carcinoma, vsarcoma, vmyeloma, vleukemia, vlymphoma v- vCORRECT✅✅Carcinoma-
vepithelial vorigin, vmost vcommon
Sarcoma- vfrom vsupportive vor vconnective vtissue
Myeloma- vfrom vplasma vcells vof vbone vmarrow v
Leukemia- vbone vmarrow, vthe vsite vof vblood vcell vproduction v
Lymphoma- vglands vor vnodes vof vthe vlymphatic vsystem
Reasons vwhy vcancer vis vdeadly v- vCORRECT✅✅Four vstages:
1. vCancer vis vlocalized vto va vsmall varea, vnoot vgrown vdeeply
2-3: vcancer vhas vgrown vmore vdeeply, vmay vhave vspread vt vlymph vnodes, vdisrupt
varchitecture
4: vadvanced vor vmetastatic- vhas vspread vto vother vsites
Cancers vnot vequally vdeadly- vhow vearly vis vit vcaught
Death vcan vbe vdue vtoo vmany vfactors:
overt vorgan vrupture vof vdysfunction
Blockage vof vdigestive vtract
systemic vcalcium vdysregulation
disrupted vblood vhomeostasis vor vfunction v
immunodeficiency
clotting vor vrupture vof vvasculature
Oncogenesis v- vCORRECT✅✅Process vof vforming vcancer
most vcells vcan vnot vdivide vindefinitely vexcept vfor vstem vcells
Oncogenesis vand vcell vculture
,senescence
immortalization v
transformation v- vCORRECT✅✅In vculture, vmost vcells vreach vsenescence vand vstop
vdividing
May vundergo vcrisis vand vdie
immortalization vis vthe vprocess vof vovercoming vsenescence vand vcrisis, vallowing
vindefinite vdivision
However, vthere vare vother vbrakes von vcell vreplication- vex vcontact vinhibition v
Transformation vis vthe vadoption vof va vfully vcancerous vphenotype
Transformation vis va vmultistep, vevolutionary vprocess
viral vinfection vcan valter vthe vevolvability vof vcells
Hallmark vtraits vof vcancer v- vCORRECT✅✅Always vpromoted: vSustained
vproliferative vsignaling, vevade vgrowth vsuppressors, vavoid vimmune vdestruction,
vresisting vcell vdeath
can vbe vpromoted:Deregulating vcellular vmetabolism, venabling vreplicative vimmortality,
vactivating vinvasion vand vmetastasis, vinducing vor vaccessing vvasculture v(get vaccess
vto vnutrients)
enablers- vby vwhich vcells vacquire vhallmark vtraits- vgenome vinstability vand vmutation,
vtumor vpromoting vinflammation
Oncogene
Proto-oncogene
viral voncoprotein v- vCORRECT✅✅Oncogene: vgene vthat vcan vinduce vtransformation
vof vcells
Proto-oncogene vis va vnormal vcellular vgene vthat vcan vbe valtered v(by vmutation vor
vsimply voverexpression) vto vbecome van voncogene
Viral voncoprotein vis va vviral vgene vproduct vthat vinduces
Most voncoogenic vviruses vblock vthe vaction vof vtumor vsuppressors
p53 vand vpRB
mutation vrate
mechanisms v- vCORRECT✅✅P53 vand vpRB vsuppress vuncontrolled vcell vdividion
regulate vcell vcycle vprogression
, stimulate vDNA vdamage vresponses
inducce vcell vdeath vwhen vdamage vcannot vbe vrepaired v
P53 vis vmutated vin v50% vof vcancers
Viruses vblock vp53 vand vPRB vthrough vthe vexpression vof vviral voncoproteins
Mechanisms vof vp53 vand vpRB vinactivation vdiffer vamong vviruses
Beneficial vto vthe vvirus vby vpromoting vS vphase vand vallowing vgenome vreplication v
Thuys, vnon voncogenic vviruses vmay valso vinactivate vthese vpathways
can vcause vunscheduled vcell vcycle vprogression, vand vaneuploidy
Proliferative vsignaling vof voncogenic vviruses v- vCORRECT✅✅allow vfor vcell
vproliferation vin vthe vabsence vof vnormal vgrowth vfactors vor vcellular vsignals
v(adhesion)
Key vcanonical vpathways voften vtargeted
mechanisms vdiffer vbeween vviruses
perturbing va vcellular vpathway vcan vlead vto vmore vthan vone vcancer vhallmark
oncogenic vviruses vpromoting vcell vsurvival v- vCORRECT✅✅if vcell vdies vit vends vviral
vreplication v
cells vdie vin vmany vways
apoptosis vor vprogrammed vcell vdeath vis va vnon-inflammatory vform vof vcell vdeath v
Apoptosis vis vpart vof vtissue vhomeostasis
apoptosis vcann vbe vtriggered vwhen vthe vcell vis vdamaged
many vviruses vblcok vapoptosis vto vprevent vcell vdeath vdue vto vinnate vimmune
vsignaling vand vdamage vresponses
often vmultiple vredundant vblocking vmechanisms
Viral vgene vproducts vfrom vsingle vvirus vinhibiting vmultiple vaspects vof vapoptosis
oncogenic vviruses vevade vimmune vdestruction vof vinfected vcells v-
vCORRECT✅✅viruses vcan vblock vinnate vimmune vpathways v(notably vinterferon)
Answers
Cancer v- vCORRECT✅✅A vgroup vof vdiseases vcharacterized vby vuncontrollable
vgrowth vand vspread voof vabnormal vcells. vif vthe vspread vis vnot vcontrolled, vit vcan
vresult vin vdeath- vgroup vof vdiseases vneoplasia
Neoplasm v- vCORRECT✅✅Tumor, vnew vgrowth- vproliferation vof vcells vno vlonger
vunder vnormal vphysiologic vcontrol
Metastasis v- vCORRECT✅✅cells vfrom vthe vtumor vseed vout vto vother vparts vof vthe
vbody vand vthen vgrow vinto vtumors vthemselves
Benign vv vmalignant vtumors v- vCORRECT✅✅Benign- vdo vnot vinvade vother vtissues
vor vorgans vand vcannot vmetastasize
Malignant- vtumors vcan vinvade vand vmetastasize
Burden voof vcancer v- vCORRECT✅✅every v6th vdeath vin vthe vworld vis vfrom vcancer
About v40% vof vpeople vwill vbe vdiagnosed vwith vcancer vat vsome vpoint vin vtheir vlives
15-17% vof vall vhuman vcancers vare vcaused vby vviral vinfectioons
Relative vranking vof vcancer vincidence vvaries vin vdifferent vcountries
Seven voncogenic vviruses vof vhumans v- vCORRECT✅✅Herpesviridae- vEBV, vKaposi
vsarcoma vassociated vherpesvirus v(KSHV)
Papillomaviridae- vhuman vpapillomavirus v(HPV)
Polyomaviridae- vMerkel vcell vpolyomavirus
Hepadnaviridae- vHepatitis vB vVirus v(HBV)
Flaviviridae- vHEp vC
Retroviridae- vHuman vT vlymphotropic vvirus v1
Not va vlot vin vcommon- vnot vzoonotic
can vestablish vpersistent vinfections
,Characteristics vof voncogenic vviruses v- vCORRECT✅✅Not va vlot vin vcommon,
vtransmitted vbetween vhumans v(not vzoonotic, vcan vestablish vpersistent vinfections
These vproperties vare vnot vunique vto voncogenic vviruses
Cancer vis vnot vneeded vfor vreplication v
Viruses vhave vnot vevolved vto vcause vcancer
Cancer vis vessentially va vby-product vof vthe vaction vof vviral vproteins von vthe vcell vto
vpromote vreplication vand vtransmission
Types vof vcancer
by vlocation v
by vtissue vtype
Carcinoma, vsarcoma, vmyeloma, vleukemia, vlymphoma v- vCORRECT✅✅Carcinoma-
vepithelial vorigin, vmost vcommon
Sarcoma- vfrom vsupportive vor vconnective vtissue
Myeloma- vfrom vplasma vcells vof vbone vmarrow v
Leukemia- vbone vmarrow, vthe vsite vof vblood vcell vproduction v
Lymphoma- vglands vor vnodes vof vthe vlymphatic vsystem
Reasons vwhy vcancer vis vdeadly v- vCORRECT✅✅Four vstages:
1. vCancer vis vlocalized vto va vsmall varea, vnoot vgrown vdeeply
2-3: vcancer vhas vgrown vmore vdeeply, vmay vhave vspread vt vlymph vnodes, vdisrupt
varchitecture
4: vadvanced vor vmetastatic- vhas vspread vto vother vsites
Cancers vnot vequally vdeadly- vhow vearly vis vit vcaught
Death vcan vbe vdue vtoo vmany vfactors:
overt vorgan vrupture vof vdysfunction
Blockage vof vdigestive vtract
systemic vcalcium vdysregulation
disrupted vblood vhomeostasis vor vfunction v
immunodeficiency
clotting vor vrupture vof vvasculature
Oncogenesis v- vCORRECT✅✅Process vof vforming vcancer
most vcells vcan vnot vdivide vindefinitely vexcept vfor vstem vcells
Oncogenesis vand vcell vculture
,senescence
immortalization v
transformation v- vCORRECT✅✅In vculture, vmost vcells vreach vsenescence vand vstop
vdividing
May vundergo vcrisis vand vdie
immortalization vis vthe vprocess vof vovercoming vsenescence vand vcrisis, vallowing
vindefinite vdivision
However, vthere vare vother vbrakes von vcell vreplication- vex vcontact vinhibition v
Transformation vis vthe vadoption vof va vfully vcancerous vphenotype
Transformation vis va vmultistep, vevolutionary vprocess
viral vinfection vcan valter vthe vevolvability vof vcells
Hallmark vtraits vof vcancer v- vCORRECT✅✅Always vpromoted: vSustained
vproliferative vsignaling, vevade vgrowth vsuppressors, vavoid vimmune vdestruction,
vresisting vcell vdeath
can vbe vpromoted:Deregulating vcellular vmetabolism, venabling vreplicative vimmortality,
vactivating vinvasion vand vmetastasis, vinducing vor vaccessing vvasculture v(get vaccess
vto vnutrients)
enablers- vby vwhich vcells vacquire vhallmark vtraits- vgenome vinstability vand vmutation,
vtumor vpromoting vinflammation
Oncogene
Proto-oncogene
viral voncoprotein v- vCORRECT✅✅Oncogene: vgene vthat vcan vinduce vtransformation
vof vcells
Proto-oncogene vis va vnormal vcellular vgene vthat vcan vbe valtered v(by vmutation vor
vsimply voverexpression) vto vbecome van voncogene
Viral voncoprotein vis va vviral vgene vproduct vthat vinduces
Most voncoogenic vviruses vblock vthe vaction vof vtumor vsuppressors
p53 vand vpRB
mutation vrate
mechanisms v- vCORRECT✅✅P53 vand vpRB vsuppress vuncontrolled vcell vdividion
regulate vcell vcycle vprogression
, stimulate vDNA vdamage vresponses
inducce vcell vdeath vwhen vdamage vcannot vbe vrepaired v
P53 vis vmutated vin v50% vof vcancers
Viruses vblock vp53 vand vPRB vthrough vthe vexpression vof vviral voncoproteins
Mechanisms vof vp53 vand vpRB vinactivation vdiffer vamong vviruses
Beneficial vto vthe vvirus vby vpromoting vS vphase vand vallowing vgenome vreplication v
Thuys, vnon voncogenic vviruses vmay valso vinactivate vthese vpathways
can vcause vunscheduled vcell vcycle vprogression, vand vaneuploidy
Proliferative vsignaling vof voncogenic vviruses v- vCORRECT✅✅allow vfor vcell
vproliferation vin vthe vabsence vof vnormal vgrowth vfactors vor vcellular vsignals
v(adhesion)
Key vcanonical vpathways voften vtargeted
mechanisms vdiffer vbeween vviruses
perturbing va vcellular vpathway vcan vlead vto vmore vthan vone vcancer vhallmark
oncogenic vviruses vpromoting vcell vsurvival v- vCORRECT✅✅if vcell vdies vit vends vviral
vreplication v
cells vdie vin vmany vways
apoptosis vor vprogrammed vcell vdeath vis va vnon-inflammatory vform vof vcell vdeath v
Apoptosis vis vpart vof vtissue vhomeostasis
apoptosis vcann vbe vtriggered vwhen vthe vcell vis vdamaged
many vviruses vblcok vapoptosis vto vprevent vcell vdeath vdue vto vinnate vimmune
vsignaling vand vdamage vresponses
often vmultiple vredundant vblocking vmechanisms
Viral vgene vproducts vfrom vsingle vvirus vinhibiting vmultiple vaspects vof vapoptosis
oncogenic vviruses vevade vimmune vdestruction vof vinfected vcells v-
vCORRECT✅✅viruses vcan vblock vinnate vimmune vpathways v(notably vinterferon)
