Synergistic effects of chemotherapy and anti-epidermal growth factor receptor (EGFr) monoclonal antibodies (MAb)

17 055 PRE-INVASIVE LESIONS GENETIC CHANGES IN RESPIRATORY TRACT. Sundaresan V1, OF THE Ganly P S1, Haslemn P*, Rudd R3, Sinha G3, Bleehen N Ml, Rabbitts P ~1. IMRC Clinical Oncology and Radiotherapeutics Unit, Hills Road, Cambridge. kepartment of Histopathology, Wythenshawe Hospital, Manchester, England. 3London Chest Hospital, Bonner Road, London, England. A variety of somatic genetic changes have been identified in lung tumours most notably point mutations in the p53 gene, rearrangements of the Rb gene and deletions of the short Amy of chromosome 3. The samples used for these studies have been fully malignant. often metastatic Nmours. With a view to identifying possible targets for early screening of this disease we wish to determine which of the genetic changes occur early in the disease process. An opportunity to do this is provided by the frequent occurrence of severely dysplasic but non invasive bronchial epithelium, which is often found adjacent to lung turnours. Allelic loss on chromosome 3 and mutations in p53 were chosen as candidate genetic changes because they occu with high frequencies in all histological types of lung tumors. Severely dysplastic pre-invasive bronchial epithelium was obtained from archival paraffm wax embedded tissue, from the mucosa adjacent to lung turnours or from the bronchial resection margin. Microdissection of this material provided distinguishable samples of both turn~ur and dysplasia from which DNA was extracted. DNA was also extracted from nomud lung. Using a PCR based RFLP analysis each patient’s constitutional genotype was determined at four polymorphic loci on the short arm of chromosome 3. and compared to the genotype of the tutnou~ and dysplastic samples to assess for allelic loss. Eleven lung Nmour samples had 3p allelic loss and their paired dysplastic samples showed an identical genotype to the tumottr. Similarly. ~53 mutations, detected by immtmohistochemistry using an antibody to mutant ~53. showed good correlation between hmmur and dysplastic samples. The results suggest that genetic changes have occurred in bronchial epithelium which, while dysplastic, is non invasive. To extend these observations we have analysed samples of severe. bronchial dysplasia which were obtained from patients free of invasive disease. Analysis of these samples confirms that somatic genetic changes take place in severe dysplasia. and suggests that such changes might form the basis of a test for early detection of lung cancer.

056 SYNERGISTIC Emcrr OF CHEMOTHERAPY AND ANTIEPIDLRMAL GROWTH FACTOR RECEPTOR (EGFn) MONOCLONIL ANTIBODIES (MAa). J Baselga, W Miller, L Norton, H Masui, C Cordon-Cardo, MG Krtt, and J Mendelsohn. Memorial Sloan-Kettering Cancer Center, New York, NY. U.S.A. Overexpression of EGFr occurs frequently in non-small cell lung cancer. To determine whether chemotherapy effects the EGFr or its ligand, transforming growth factor-a (TGFa), we conducted experiments wtth squamous carcinoma cell line A431 that expresses high numbers of EGFr. Treatment of cultured A431 cells with Adriamycin (ADR) at a concentration of 40 nM produces a 5 fold increase of TGFa mRNA. Thii increase is detected during the first 2 hrs, reaches its peak at 6 hrs, and returns to baseline by 72 hrs. Since this could represent an activation of the TGFa/EGFr loop in response to ADR, we then added anti-EGFr MAb 526 to the ADR treated A431 cells. White ADR alone (2OnMx2days) caused a 10% inhibition by day five, this inhibition increased to 67% when anti-EGFr MAbs was added. In nude mice with established A431 xenografts we tested ADR (1 Omg/kg), anti-EGFr MAb 526 (1 mg twice weekly), or a combination of both, all given intraperitoneally. While ADR or MAb 526 alone produced transient growth inhibition, all animals treated wlth ADR plus anti-EGFr MAb had complete regression of their tumors, with no regrowth after 70 days. The animal death rate was also significantly lower with the combination. We conclude that in A431 cells: 1) ADR increases TGFa mRNA; 2) The combination of ADR and anti-EGFr MAb is synergistic in cell cutture and xenografts; 3) Trials in humans with combination chemotherapy plus anti-EGFr MAbs are warranted.

057 INHIBITICN OF HUMAN LUNG CANCER mASTASIS USING ANTIPLATELET DRUG AND SIALIDASE Hamhiko InufusaS, Toshiyuki Adachi§, Nobuhira Masato Tanaka§, Satoshi Ham§, Nobuya MoriS, NakaniuraS, Masayuki Yasutanig and Yukio Kirmraql SDepartrnent of 1st. Surgery. Kinki University School of Medicine. Osakasayana, Osaka, 589 Japan TlOtsuka Pharmaceutical Co., Tokushima 771-01 Japan Cell surface glycolipid expression and platelet aggregating potential of cancer cell is very wortant factor in the blood borne metastasis. Hursan lung xlenccarcinana cell line with different Ixetastatic potentials in nude mOuse were established using limiting dilution technique. Cell lines HAJA and HAL33 by high and low metastatic were characterized potential to the lung respectively, while HAL24 was ncnmetactatic when cells injected into tail vein. In these 3 cell lines, correlation was observed between sialosyl Iex(defined by mcncclonal antibody R16) flcW potential by metastatic cxpressicn and cytometory. Metastatic cell lines HAI8 and HAL33 platelet aggregating shcnvcd human heparinized potential. To inhibit these cells mctastosis 1)Cclls were treated with ncuraninidase just before injection to reduce sialosyl glycolipids. 2)Nude rr,icewere pretmatcd with Cilostazol(an inhibitor of platelet digestion. nuclcotide phosphodiesterase) cyclic Dcsialylation of cells were inhibited nvetastaois reducecl mctastasi's Cilostazol ccmplctcly and approximately 90%. These results suggest that antiplatelet drug and sial-acid inhibition ~1 useful tn reduce hunwn lung cancer blood bomc ioetastcsis.

MEI'ASTATIC ~IXNI'IAL OF HUMAN LUNG ADENXARCINOMA CORREIATE WIT?1 PIASMINOGFN ACTIVATOR PROWCTION, NOT CORRELATE WITH PIATELETAGGRFGATING POTENTIAL AND CELL ATTACHMENT ACTIVITY Toshiyuki Machi, Haruhiko Inufusa, Nobuhira Mori, Satoshi Hara, Nobuya Tcanaka, Manato Nakanura, Masayuki Yasutani Deparbrent of 1st. Surgery. Kinki University School of Medicine. Osakasayana, Osaka, 589 Japan It has been mported that intemcticn between cancer cells and the ECM (extracellular matrix), platelet aggregation or PA (plasmincgen activator) is prime isportant in cancer metostatic system. Human lung adenccarcinana subcell lines HAIS, ML33 and HAL24, shawing high, low and non metastatic potentials in nude muse, was established fran human lung adenocarcinam cell line KUMLKZ using limiting dilution technique. These cells attacivrent activity to the substance of !ZM (laninin, fibronectin and type IV collagen) was not correlate with metastatic potential. Them significant correlation between was no platelet aggregating metastatic potential and potential of 3 cell lines. cx1 the other hand, cell release of PA in the tissue culture medium was correlated with metastatic potential. There was s?any reports that presents irrportance of cell attachrent activity and platelet aggregating potential in cancer metastasis. However mctastatic made1 of HAL cell lines were not correlate with these characters. Therefore we suggest that n-etastatic potential of this cell lines is depended on the PA prcducticn which lysis fibrin or thrombosis in the bleed borne metastatic systems.