AFCR ONCOLOGY
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`459A
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`TOPOISOMEP~%SE-HEBIATED DNA D~DE IS CfLL CYCLE DEPENDENT. D.~
`~, S Smallwood,* P Hedges,* and WE Ross, Departments of Pharma~
`~ology and bledicine, Univecsity of Florida, Cainesville, FL.
`M~ny antitumor drugs induce DNA strand breaks (St) via stabilization
`of a DNA-topoisomerase II "cleavable complex." We have examined the
`relatioeshlp between this phenomenon and cell proliferation using the
`intercalating agent m-~MSA and nhe non-lntercalatlng epipodophyllotoxin
`Vp.16. Wild type CHO cells were tremted with drug at several points
`~la~g the gro~=h c~rve and the resul=inB gB’s quantified hy alk~llne
`el~tion. An inverse relationship between =he SB frequency and cell
`density was observed, i.e., early log phase cells demonstrated the
`greatest SB frequency, while lace plateau phase ee!~s (predominantly
`by flow cytometry) showed no drug-induced SB’s. Addition of fresh
`growth media did not alter drug sensitivity. Uptake of [3H]~VP-16 was
`sos significantly different between lag and plateau phase cells.
`covaty of drug seusitivity hy trypsinlzed plateau cells seeded at low
`densi=y in new growth media was colneident with DNA synthesis as mea-
`sured by [3g]-thymidlne inaorporanion. However, inhibition of DNA
`synthesis by aphidi=olin did not ~ffect recovery of drug sensitivity,
`plateau phase cells also demonstrated ~mrked resistance to the ezra-
`toxic effects e[ WP-16 when compared to log phase calls. Our data
`suggest that ~he proliferation-dependent cytotoxicity of these agents
`is conferred by regulation of tepoisomerase II activity during the
`sell cycle. This likely provides the basis for some of the therapeu-
`tic selectivity of these dru~s. In addition, our data indicate that
`topoisomerase II and DNA polymerase ~ are not coordinately regulated
`as has been suggested for other putative components of the multienzyme
`replitase complex.
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`IMPORTANCE OF IMPAIRED rRNA PRODUCTION IN FLUOROPYRI}~IDINE CYTDTOXI-
`ciTY, CH Tahimoto*. EC Cadman and RD Armstrung, Cancer Research Insti-
`
`However, the precise mechanism of RNA related cytctoxicity has not been
`
`0V~RCO~ING COLON CANCER R~SISTANCE ~D HEPATIC .~T~RY INPDSIONAL
`CHE~THERAPY WITH FOLINIC ACID. Glenn Tismsn, Fictoria Flea,r, Hary E.
`Jones~ L~ette Bu~k. Whittier, CA. 90601.
`Reduced relate polyglut~at~s ~nhance binding of th~idylat~
`th~tase to 5Pd~P. Increasing intrac~llular reduced relate concentra-
`tions i~ sssocia=ed wi~h revers~l of cell r~sistance to 5FUdR in some
`tumor cells. We have demonstrated that patient red bloo~ c~ll poly-
`glu~Rtes c~n be elevated by treating with large doses of intravenous
`f~lic xcld plus Cy~ocobal~in. Per~, J., 1979 has sho~ that
`Leucovorin c~ increase intracellular pslyglut~es. ~o patients with
`extensive hepatic metastases fro~ colo~ cancer w~Ye g~eated with i~tra-
`hepatic arterial infusions of 5FUdR 0.1-0.~mg/kg/d. One patient
`sponded initially ~d thee relapsed; ~no~her was resistant from the
`start. Both patients had a rapid tumor response when Leucovorin was
`added to ~he 5FUdR. In one patient ~ of the resistant dose of
`[O.15m~/k~/d) when mixed with Leucovorin ~O,07Smg/kg/d) produced
`response clearly demonstrating enhancemen~ ~£ 5~U~R activity. The
`second patient r~ceived 0.2mg/kg of 5FUdR for 18 days without response.
`Two days ~fzer adding Leucovorin 0.2mg/kg/d t0 th~ infusRte
`p~tient had ~apid iysls of fever. R~peat ~nglography20 days later
`revealed 60% decrease in ~or size. The abo~e anapests that
`Leucoverin may potentiate 5FUdR sctivi=y when both d~gs are given
`through th~ hepatic artery.
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`POSSIBLE POT£NTIATION OF FLUOROPYRIMIDIN~ ANTI-TUMOR ACTIVIYY BY
`PTEROYLGLUTAMIC ACID (NOLIC ACID) AND CYANOCOBALA~|IN (B12). Glenn
`Tisman, Victoria Planer, Mary E. Jones, Lznette Buck. Whittier, CA.
`90601.
`Laborataryatudies confirmed ~hat both folini¢ acid and folio acid
`nan potentiate 5FU activity against different tumo~ cells. Our pre-
`liminary clinical work with attempts to potentiate 5FU activity with
`low doses ~amg) of Lencevorin was unsuccessful [Tisman, at.el., AACR,
`19, 197B, 217~). Because folio ~cid m~y be the preferred substrata for
`intracellular conversion to polyglutamates [Perry, J., at.el., 1979),
`a~d because reduced relate polyglutamates potentiate the binding ~f
`5~di~P to thy~idylats synthetase, we f~it tba~ l~r~e doses of folio
`acid might potentiate 5FU oncolytic effects clinically. Polio acid 20D
`mg/m2 plus Cy~ocobelamin 10,0COmaE [used to enhance intrRcellular
`transport of folate~ [Herbert, Tisman, at.el., Blood 4:d65, 1973~ in
`200mi. of ~N saline plus 20HEq of sodium bicarbonate was infused
`over 2 hours daily for 3 days. After the first hose of each infusion a
`bolus of 5~U 200m£/m2 was given I.V. Each treatment was repeated ~eekl)~
`Thus far 3 patients with breast cancer refractor~ to SFU containing
`regimens hare received ~6 infusions. Two of 3 patients had an exacerba-
`tion of bone pain within 12 to 4B hours Of initiation Of £herspy. All
`patients had subsequent alleviation of bone pain within i week.
`biters decremsed fn all patients. Hematologic toxicity was not signi-
`ficant in 2 ~d mild in one. ~’o of three patients devsloped
`at the end of 1 and 3 weeks, Red blood cell relate levels after therapy
`revealed red cell relates (pelyglutsmates) wets 2 to 3 times hemal,
`The above profocol is clearly associated with tu~er response to 5PD in
`
`BIOPHYSICAL AND ULTRASTRUCTUNAL CHARACTEKISTIOS OF A SARCOMATBID RENAL
`CELL CARCINOMA. D.A. Terraroe. A. Bahb~hani~ ~. King~ and F. Cuppmge.*
`Department off Pnthology, University of Kensas~ Ksnsms City. Kansas.
`Classification of renal neoplasms has been controversial as the
`kidney is a mesodermally derived organ. A clear d~stlnstion between
`the less dlfferent~ated sareomatold variant Df renal carcinoma and
`llbrosarcema is =umbersome. Tea purpose of this work was to study a
`primary renal sarcoma-like tumor that developed in the bydron~phrotla
`kidney of an elderly female. Toe primary tumor and its metastases to
`hone and skin had a spindle cell sarcoma-like morphology. Cultures
`were star~ed with cells obtained from cystic and solid tu~or areas.
`2~e ¢ell lines are presently {n passages 59 an~ 52 res~ectlvelv. ~
`cells grow ~11 in ea~le~s media with or wi£hout serum supDlement,
`Both cell l~nes possess proximal tubular intercellular junctions,
`microvilll ~larlzed towards the nutr£enh media~ a~d multiple cellular
`inte~diK~a~ions. ~elr karyo£ype is hypodiploid wi£h variable
`c~ro~osoa~al rear~an~ements and constant C-I and ~-3 mon0ssmy. ~SV-I
`and 2, Adeno-5, Echo l! and CoK-B v~ruses reDlicate well in bach l~nes.
`By means of [ntracellularly placed m~croelec~v~des, a cellular elec-
`tromotive [orc~ of -16 + !~V S.E.M, (No70) was found. ~s value ~s
`s{gnif{=an£1v lo~r th~ those measured by us and oKhers in non-neo-
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`cin~a (Nature 186:402, 1960), giving fur=her i~s~ht into the bioloEy
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`CLINICAL RESEARCH, VOL, 33, NO, 2, 1985
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`Sandoz Inc.
`Exhibit 1028-0001
`
`JOINT 1028-0001