29

110

IN VITRO DRUG SEfWTMTY TESTING OF CELL LINES FROM EXTFJ’I- SlVEVSLlMlTEDSMALLCELLLUNGCWCER@CLC)P.4TlENTS E.G. Fe&l, SM. Steiabq AI’. Gazdar, E.K. Rwdl, D.C. II&, B.B. Jolmon. National Cancu lnstihdt and Naimal Naval Medical Cutter, Be&&, MD, USA

Inordatocanpsns~~c~Lines~~~w~~ ofSCLCtotiCUSC~egClUS,~ntndicddlinesf~CetSWitll extcapivcandlimitedgaBcdircasc. IntibudNSsedidy~(DST)~gIbe Weismhrldycaclusionassaywar~~~plntdpoapEtivc~on31 hmorcelllithn115(27%)prchody~~withcxtmsivcmlSc diswseand9fmm53(17?c)tithlimitcdstuSc~. Twmty-(23%)of115 patiauswithextensivesul~~badacRto~ and66(57%)hadS PR(8O%o~erall). Thialy+i,ghI (72%)d53patimt~withlimital24BcSCLChada CRtommbiimodalitytherepy(~plusclKet~)end13 (25%) had a PR (97% mmall). The in vitro DST was pmfbnmd usiq tk drugs Iii belowaspmriousfydescn‘brd(JNCI82:1117)withrriaogenmurtard~asm alkylatinS agent for cyclqhos@h& which requim in viva Mivstion

109

RELATIONSHIP BETWEEN TUMOR RESPONSE AND THE NUCLEOTIDE TRIPHOSPHATES (NTP) TO INORGANIC PHOSPHATE IPI) RATIO IN SMALL CELL LUNG CANCER. P.E.G. Krfstjan&n.‘C.A. Kristensen, M. Spang-Thomsen, B. Quistorff. Department of Cncofcgy, The Finsen lnstftute; Laboratory of Tumor Pathobgy, and NMA-Center, Unfversfty of Copenhagen, Denmark.

The ratio of nucleotfde trfphosphates (NTP) to inorganic phosphate (Pi) in tumors, monftored during therapy by phosphorcus magnetic resonance spectroscopy (31PMRS), has been proposed as an early response parame- ter, useful for predktiie purposes with different antineoplastic therapies. It is unclear if this oarameter can credkt tumor resconse in diiererrt turnOffi Me- pendent of the type of therapy. We examined whether comparable tumor re- sponses, obtained by d8ferent types of therapy induce similar changes in the NTPlPf in two human tumor lines, derfved from the same patient tumor. Tumor responses were induced by doxombfcin 10 rngkg Lp. or 5 Gy X-irradi- ation in the human small cell lung cancer (SCLC) lines 54A and 548, grown as xenografts in nude mice. 31 P-MRS of tumors was performed pretherapeutk tally;and on days 1,4,8, and 15 following therapy, in a 4.7 T magnet. Individual NTP/Pi ratios were calculated relative to the cretheraceutic value at each measurement. Treated (n=28) and ccntrols (n=i8) were compared by non-parametric anafysis. In both tumor lines, doxorubfin induced a significant drop in NTP/Pf at day 1. In the 54A turnots, radffthempy induced a sfgnifkant increase in NTP/Pf, at days 1,4, and 8, whereas no difference between the NTP/Pi of irradiated and cmtrols was found in 546 tumors. Among 4 different treatment-tumor combinations, each with significant tumor response, 3 dis- tinct 31P-MRS patterns were observed: (1) A deU8aSe in NTP/Pf, (2) an in- crease, and (3) IX) c/range. The time course of changes in this ratio was quite scecBi for each of these 4 aroucs. and the variatbn within aroucs was low.

We conclude that char&s in the NTP/Pt ratff dc not &relate indepen- dently wfth tumor response. The NTP/Pt ratio appears to be of questionable future use as a response parameter in SCLC, except for in pmclinfcal experf- mental models, where the energy metabolic inte’mctffns‘of the particular treatment-tumcr constellatffn is well characterized in advance.

111

EFFECTS OF THE MULTIDRUG RESISTANCE MODULATORS DEXNICZJLDIPINE, VERAPAMIL, AND CYCLOSPORIN A ON DRUG ACCUMULATION AND CYTOTOXICITY IN MDR- 1 AND MRP EXPRESSING LUNG CANCER CELL LINES. D. Chart, S. Sobolevsky, D. Kirpotin, B. Helfrich, K. Helm, P. Bunn. Univ. of Colorado Cancer Center, Denver, CO. 80262

We sought to determine whether dexniguldipine(dex)(-stereoenantiomer of niguldipine without its cv efffects),verapamil (vpr), or cyclosporinA (csa) could overcome MDR -1 AND MRP associated drug resistance in small lung cancer cell lines (H69 parental , Adria resistant H69ADR with MRP, VP16 resistant H69VPR2 with MDRl) and squamous cancer cell lines (KB parental[KB-3-Hand resistant [KB-8-51 with MDR-1). MDR expression was asssessed using the moab 4E3 and rhodamine 123 uptake by flow cytometry. Drug cytotoxicity was measured in M’IT assays. Concentrations of dex(luM), vpr(5uM), and csa(L6uM) were non- cytotoxic alone. The results were:

Rh123 UPTAKE ICSOINDOX’PLUS IC5OINVP16 ‘PLUS LJfs s?m~&&~~~&S~rpr~IlpoevJ~ H69P 6% 100 nd nd loo <I <I Cl <I 5 5 5 5 H69vpr2 95% 43 67 50 90 >20 <I <1 <l >20 3 5 5 H69ADR 6% loo 120 98 109 nd nd nd nd nd nd nd nd KB-3-l 13% 100 74 nd nd <1 <1 <I <l 1 1 1 1 KEGS-5 40% 2s 54 68 50 5 cl <I <l 8 1 1 1

nd=not done pend=pending ‘=ughll

The results show a higher MDR expression and lower Rh123 uptake in the MDR-1 resistant than parental but low MDR expression and high Rh123 uptake in MRP resistant lines, that the 3 modulators increased Rh123 uptake in MDR-1+ and only slightly in MPR+ lines, but not to parental levels and all 3 modulators decreased the It& levels in resistant cells to parental levels or less. We conclude that all 3 agents should be evaluated in lung cancers with an MDR phenotype with priority to dex because it affecs both MDR-I and MRP and its lack of toxicity at 1uM a concentration which can be achieved in humans.

1 N median (nagrl N mulian (nmge) P EtOpide 30 49 (o-loo) 9 47 (4-100) 0.55 CiSDhtb 25 64 cl-loo) 9 56 (33-W) 0.97 Dor;orubicin 30 72 &J-lod) 9 80 {lz-moj 0.65 Nitmpn mustard 30 54 (O-100) 9 62 (22-100) 0.35 vii& 29 89 (12-100) 9 78 (52~100) 0.78 cm-u 30 71 (O-100) 8 56 (3-100) 0.73

30 88 (23100) 9 n e6-100) 0.91

Cosdurba:WeprcviouslyrcponedsclosccomiationkhmeninvihoDSTand clinicalrtspoosein~~udcnsivcstegcSCLC(JNCI82:111’1). Despitea >3foldbighnCRratcinp&dswithlimitrdvsextfmb~ thcinvim

semitidyasmcaJurcdbythcW~dyeexclusion~issimilarinpatice~ wiullimitcdaad~We~SCLC.Tbehighanrpoarrate~in~~ withlimitedsIagcSCLcmaybe&ctotheedditionofcbeStrs&&apyto chematharWin~~wifhlimitcdstPgcdisaac.F~studicsusiogththiTIT assay.mongoingtoieVestiSatcthisfortha.

112

MDRl GENE EXPRESSION AND TREATMENT OUTCOME IN SMALL CELL LUNG CANCER. M. Tabata, T. Ohnoshi, H. Ueoka, K. Kiura, Y. Segawa, T. Shibayama, I. Kimura. Second Department of Medicine, Okayama University Medical School, Okayama, 700, Japan.

We report a study to determine whether MDRl gene expression level in small cell lung cancer (SCLC) tumor is a useful predictor of tumor response to chemotherapy and patient survival. Transbronchial biopsy specimens were obtained from 18 patients with SCLC at diagnosis between August 1989 and November 1991; 16 males and ‘2 females, median age of 68 years, and 7 with limited disease (LD) and II with extensive disease. AU the patients tested received CAV-EP chemotherapy consisting of cyclophosphamide, doxorubicin, vincristine, cisplatin, and etoposide. MDRl mRNA expression levels in biopsy specimens obtained at diagnosis were determined by RT-PCR. The feasibility of RT-PCR method was tested in the human SCLC cell line SBC-3 and its adriamycin resistant sublines. As a result, all sample! were negative for immunohistochemical staining using anti-p-glycoprotein monoclonal antibody C219. However, we were able to measure the MDRl mRNA levels in all samples using RT-PCR method. Five patients were determined to have high MDRl expressing tumor and remaining 13 patients were determined to have low MDRl expressing tumor. Patients with tumor expressing low MDRl mRNA responded more favorably to chemotherapy than those with tumors expressing high MDRl mRNA. In spite of higher proportion of LD patients in the high MDRl group, the overall survtval was sigmficantly shorter in the latter than io the former (7.2 months versus 11.7 months: p=O.O23). Finally, it appears that patients with high MDRl mRNA level are resistant to CAV-EP chemotherapy and have poor prognosis.