129

Distribution of radiolabelled monoclonal antibody Po66 after iatra- veaous injection into nude mice bearing human long cancer grafts Desrues B, Collet B, Rame MP et al. Service de Pneumologie, Cenfre Hospiralier Regional. Ponrchaillou. F-35033 Rennes Cedex. Cancer lmmunol Immunother 1989;30:295-9.

Monoclonal antibody Po66, produced by immunization against a patient’s lung squamous cell carcinoma was found suitable for the scintigraphic detection of human turnours. Surprisingly, the cellular antigen recognized by Po66 was abundant in the cytoplasm of tomour cells but could not be detected on the surface membrane. In the present work the biodisuihution of radiolabelled Po66 and of an unrelated immunoglobulin were studied comparatively after intravenous injec- tion into nude mice bearing lung squamous cell carcinoma grafts. Radioactivity distribution among mouse organs and tumour was ana- lyscd by gamma counting and autohistoradiography. After injection, radiolabelled Po66 decreased rapidly from the blood in tumour-bearing animals whereas, in controls, it remained at a level comparable to that of the unrelated immunoglobulin. The antibody seemed slowly trapped by the tumowand, 12daysafterits injection,distributionratiosbetween tumour and mouse organs reached values of 20-30 as against 1 in animals injected with the non-specific immunoglobulin. Autohistoradi- ographic investigations in the turnour confirmed the slow diffusion rate of the antibody, which remained in the vascular spaces up to the 24th hour after injection and diffused afterwards throughout the clusters of tumor cells. Furthcrmorc, radioactivity was detected in cells which, unexpectedly, seemed morphologically unaltered. These cells, the viability of which remains to be determmed, wcrc predominant in the central area of the turnours. The results presented constitute new evidence of the ability of an in viva injcctcd monoclonal antibody to reach a cytoplasmic target inside non-necrotic cells and suggest that the cells permeable to the antibody might be in defective nutritional conditions.

Amplification of protooncogenes in surgical specimens of human long carcinomas Shiraishi M, Nogochi M, Shimosato Y, Sekiya T. Oncogene Division, Nalionai Cancer Cenler Research Inslilure. l-1, Tsuki) 5-chome, Chuo-ku. Tokyo 104. Cancer Res 1989;49:6474-9.

The possible existence of amplification or rearrangement of protoon- cogenes was examined in more than 100 surgical specimens of human lung carcinoma. Protooncogenes were amplified in 28% of the carcino- mas. About 90% of the amplified genes were of the myc, ras, or erbB family. Ofthemyc familygenes,myc wasamplifiedin l4of 137 tumors and L-myc in four of I08 tumors, but N-myc was not amplified. A high frequency of amplification of myc was observed in squamous cell carcinomas (seven of 37) and of L-myc in small cell carcinomas (two of six). Of the ras family genes, K-ras-2 was amplified in six of the I37 tumors and N-ran in two of the 137 tumors, but no amplificalton of H- ras-1 was dctccted. Seven of the eight cases ofamplificd ras genes were in advanced pathological stages. Of the erbB family genes, erbB-1 (epidcrmal growth factor rcccptor) was amplified m 10 of 1 I4 tumors and erbB-2 (HER-2/ncu) in one of 51 tumors. Amplifications of the myc, ras, and erbB family genes might be one of the crucial DNA abnormalities involved in the development of human lung carcinomas.

Differentiation of human variant small cell lung cancer cell lines to a classic morphology by retinoic acid Doyle LA, Giangiulo D, Hussain A, Park H-J, Yen R-WC, Borgcs M. Universiq of Maryland Cancer Center. 655 W. Baltimore Sf., Balti- more. MD 21201. Cancer Res 1989;49:6745-51.

Variant small cell lung cancer (SCLC) is distinguished from the classic histology by changes ingrowthcharactcristicsand morphology, c-myc amplification, a loss of some biochemical markers, and relative chcmo- and radioreslstance. Three variant SCLC lines were incubated in 1 pM all-trans retinoic acid. After 8.10 days, a marked change in morphology was noted in all three iincs, with tightcell aggregation and

central necrosis of large floating spheroids similar to classic SCLC. The retinoid-treated cells demonstrated decreases in growth rate and clon- ing efficiency to levels comparable with classic SCLC cell lines. Retinoic acid incubation caused a reproducible decrease in c-myc expression in variant SCLC cells, but was not noted to increase L-dopa carboxylase, an enzyme which biochemically distinguishes classic from variant SCLC cell lines. Rctinoid exposure led to an increase in HLA and Lea-7 antigens, but a reduction of antibody binding to 3- fucosyllactosamine, a dominant SCLC glycolipid antigen. Clonogenic assays revealed that the variant cells, after incubation in retinoic acid, became more sensitive to etoposide, but more resistant to Adriamycin. We conclude that exposure of variant SCLC cells to retinoic acid can lead to a morphologic phenotype similar to classic SCLC, but with substantial differences in cell biology.

Synthesis and secretion of plasminogen activators and plasminogen activator inhibitors in cell lines of different groups of human lung tumors Heidtmann H-H, Hofmann M, Jacob E, Emil C, Havemann K, Schwartz- Albicz R. Departmenr of Inrernal Medicine, Division of Hematology/ Oncology. Philipps University, 3550 Marburg. Cancer Res 1989;49:6%0- 5.

Several human lung tumor cell linesderived from largecell, squamous cell, and small cell carcinomas, as well as from mesotheliomas of the lung have been investigated for their gene expression and secretion of urokinase-type plasminogen activator(u-PA), tissue-typeplasminogen activator (I-PA), and plasminogen activator inhibitors 1 and 2. All bronchogenic non-small cell carcinoma-derived cell lines studied could produce either plasminogen activators, their inhibitors, or both compo- nents, whereas in small cell lung carcinoma cell lines and cell lines derived from mesothelioma of the lung, no substantial amounts of any of these substances were synthesized. In detail, a large cell carcinoma- derived cell line, LCLC 97TM1, constitutively secreted large amounts ofplasminogenactivatoor. Northern blotanalysisrevealedRNA specific for U-PA and t-PA. Another large cell carcinoma-derived cell line, LCLC 103H. secreted smaller amounts of asminogen activator and, additionally, plasminogcn activator inhibitor. Specific mRNAs for u- PA and plasminogen activator inhibitors 1 and 2 were found in this cell line. In contrast, squamous cell carcinoma-derived cell lines secreted plasminogen activator only after treatment with the phorbol ester 12-O- tetradecanoylphorbol-13-acetate; enhanced levels of u-PA, t-PA, and plasminogcn activator inhibitor 1 mRNAs could then be demonstrated. The different expression of the plasminogen activator enzyme system distinguishes cell lines derived of non-small cell lung carcinoma from those of small cell lung carcinoma and may also reflect significant differences in the biological behavior of these tumor types.

Lung cancer cells often express high levels of protein kinase C activity Hirai M,Gamou S, Kobayashi M, Shimizu N.DeparrmenlofMolecular Bwlogy, Keio University School of Medicine, 35 Shinanomachi, Shin- luku-ku, Tokyo 160. Jpn J Cancer Res (Gum) 1989;XO:204-8.

We analyzd protein kmase C (PKC) activity in twenty-two tumor cell lines derived from long, pancreas, stomach, tongue and vulva, and found that lung cancer cells often (9 out of 13) exhibit significantly higher PKC activity than other types of cancer cells. The PKC in these lung cancer cells was separated into one major and one minor peaks by a Mono Q column chromatography. The PKC in the major peak had an absolute requirement for Ca*+, phosphatidylserine and 12-O-tctrade- canoylphorbo-13.acetate(TFA),ascxpected. However, thePKCinthe minor peak did not require TPA for its activation. Hydroxyapatite column chromatography revealed that the PKC in the major peak is type 111. These results indicate that in lung canccrcells type Ill PKC activity is often elevated compared to other types of cancer cells. The growth of many lung cancer cell lines was Inhibited by TPA.