P-58
医療・福祉・介護
医療・福祉・介護CARF Overexpression-mediated Growth Arrest
CARF Overexpression-mediated Growth Arrestof Cancer Cells Involve p53 Proteinof Cancer Cells Involve p53 Protein■ はじめに■ Collaborator
はじめに of ARF (CARF) has been shown to bind toCollaborator
ARF (CARF)
shownoftop53-p21
bind toARF, p53 and ofHDM2
resultinghas
in beenactivation
ARF,p53
andHDM2
resultinginactivation
ofp53-p21
pathway. Overexpression of CARF was shown to cause
pathway.
Overexpressionof CARF
was thatshownto cause
growth arrestof osteosarcoma(U2OS)
harbors
wild
growtharrestofosteosarcoma(U2OS)
that
harborswild
type p53 function. Its knockdown caused apoptosis
typep53 thatfunction.
knockdown
suggesting
it is anItsessential
survivalcaused
protein.apoptosis
In ordersuggesting
that
it
is
anessentialsurvivalprotein.
order
to investigate the critical involvement of Inp53
intoinvestigate
thecriticalinvolvementofp53
in
CARF-induced growth arrest, we used p53-compromised
CARF-induced(Saos-2, MCF7)growthcells. arrest, we used p53-compromised(Saos-2, MCF7) cells.
■ 活動内容■ In
活動内容
order to validate the involvement of p53 inIn
order togrowthvalidate
theof involvementof p53used
inCARF-induced
arrestcells, we presently
CARF-induced
growtharrestofcells,
wepresently
usedcells that lack functional p53.
cells that lack functional p53.
１． Ｉn vitro/in vivo assays for CARF-OE Saos-2 cells
Ｉn foundvitro/invivo
assaysfor CARF-OE(OE)
Saos-2cells cells
１．We
thatCARF
overexpression
in theseWe
foundthatCARF
overexpression(OE)inthesecells
lead to increase in proliferation rate and malignant
leadtoincrease
inproliferation
rateandmalignant
transformation (Fig. 1 b and d).
transformation (Fig. 1 b and d).
２． Molecular analysis
２．We
Molecularanalysis DNA damage response (ofinvestigatedWe
investigatedDNA
damageresponse (ofATM/ATR/CHK1/CHK2
pathway)in p53-compromised
ATM/ATR/CHK1/CHK2
pathway)inp53-compromised
cells, similar to the one performed for p53-functional cells.
cells,
similar to theperformed
p53-functional
cells.
We observed
thatonealthough
thefor early
DNA damage
Weobserved
thatalthough
theearlyDNA
damageresponse elements were upregulated in p53-compromised
response
elements
p53-compromised
cells similar
to thewere
one upregulated
observed in in
p53-functional
cells,
cells
similartotheoneobservedinp53-functional
cells,
pERK1/2 was upregulated and was in sharp contrast to
the
pERK1/2
was upregulated
and wasitsindownregulation
sharp contrast (Fig.
to the1
p53 fucntional
cells that showed
p53
fucntional
cells thatshowed ofitsCARF-OE
downregulation(Fig.
1a andb). In addition,
treatment
Saos-2cells
awithand b).
Inaddition,
treatmentofCARF-OE
Saos-2cells
ERK1/2 inhibitors caused decrease in theirwithERK1/2
causeddecrease ofinERK1/2
theirproliferation
rate inhibitors
suggesting thatthe activation
proliferationratesuggestingthat
theactivationofERK1/2
was involved in increase in proliferation caused bywasinvolved
in increasein proliferation
caused by
CARF-OE
in Saos-2cells. Furthermore,
overexpression
CARF-OE
in
Saos-2cells.
Furthermore,
overexpressionof CARF in MCF7 cells also led to an increase in theofCARF inlevel
MCF7cells also
to an increasein withtheexpressionof CHK1/2
andledγH2AX,comparedexpression
levelofCHK1/2
andγH2AX,comparedwiththe controls (Fig. 2).These data suggested the activation
the(Fig. 2).Thesethe normal
activationof controls
DNA damage
responsedatabysuggested
CARF isinofDNA
damageresponseby
CARF
isnormalp53-compromised cells and lack of growth arrest is due into
p53-compromised
and lack of growthis due toabsence of p53 andcells
its down-stream
effectorarrest
pERK1/2.
absence of p53 and its down-stream effector pERK1/2.

■ 関連情報等 （特許関係、施設）■ 関連情報等 （特許関係、施設）

代表発表者
代表発表者
所属
所属

■キーワード： （1）CARF（2）p53■キーワード： （1）CARF（3）DNA damage（2）p53（3）DNA damage

Mijung KIM（キム ミジョン）
Mijung
KIM（キムNationalInstituteミジョン）
of Advanced Industrial
National
Advanced Industrial
Technologyof(AIST)
Science & Institute&Technology(AIST)
Science
問合せ先 Central 4, 1-1-1 Tsukuba, Ibaraki 305-8562, Japan
TEL：029-861-2900
FAX：029-861-2900
問合せ先 Central4, 1-1-1 Tsukuba,Ibaraki 305-8562, Japan

(a)
(a)

(b)
(b)

(c)
(c)

(d)
(d)

Fig.1. Overexpressing CARF (CARF-OE) caused growth arrest
Fig.1.
Overexpressing
CARF (CARF-OE)
growthin cancer
cells with functional
p53 plus cellscaused(a). p53
minusarrest
cells
incancerincrease
cells with
p53inplus(a).c,p53
cells
showedin functional
proliferation
vitrocells
b andandminus
malignantshowedincreasein inproliferationin vitro b and c, and malignant
transformationin vivoassays (d).
transformation in in vivo assays (d).

Fig.2. Overexpression CARF caused DNA damage response in
Fig.2.
CARF
causedDNA damagep53
responseinHumanOverexpression
breast carcinoma(MCF7)with compromisedfunction.
Human breast carcinoma (MCF7) with compromised p53 function.

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