equivalent of bombesin. There is some evidence to support the sugges- tion that GRP is an autocrine regulator of SCLC growth. Therefore, we have tested the effect of hombesin and two antagonists of bombeain on SCLC cell growth in a serum-free liquid tissue culture system. The antagonists used were analogues of substance P: spantide and (D-Arg’, D-Pro*, D-T~TI”,~, Leu”) substance P. The cell lines used in this study all produced GRP-related peptides and one line had demonstrable GRP receptors. Exogenous bombesin did not cause any stimulation of growth in the liquid culture assay. The bombesin antagonists inhibited SCLC cellgrowth, butapparentlynotviathebombesinreceptor.Thebombesin used was biologically active because it stimulated the proliferation of Swiss 3T3 fibroblasts. The antagonists caused inhibition of this bomb- esin-induced proliferation, which was reversed by addition of excess bombesin. In addition, the antagonists and substance P alone stimulated proliferationof3T3 cells, indicating that they may intcractwithanother growth factor receptor on 3T3 cells. We conclude that growth of SCLC cells is not dependent on bombesin under all in vitro culture conditions because bombesin failed to stimulate growth in liquid cultures and the growth inhibition caused by bombesin antagonists was probably not mediated by the bombesin receptor.

myc family DNA amplification in small cell lung cancer patients’ tumors and corresponding cell lines. Johnson BE, Makuch RW, Simmons AD, Gazdar AF, Burch D, Cashell AW. NCI-Navy Medical Oncology Branch, National Cancer Inslilule, Naval Hospital, Berhesda, MD 20814. Cancer Res 1988;48:5163-6.

Tumor specimens procured from 38 different small cell lung cancer patients were studied for DNA amplification of the myc family of protooncogenes (c-myc, N-myc, and L-myc). Six of the 38 specimens (16%) had 4.fold or greater myc family DNA amplification (N-myc in 4 and L-myc in 2). All 6 tumors with amplification came from patients who had received combination chemotherapy. The myc family gene copy number of the DNA prepared from 9 tumor cell lines established from these 38 patients was similar to the myc family gene copy number in the DNA prepared from fresh tumor specimens from these same patients. myc family DNA amplification is present in 16% of small cell lung cancer patients’ tumors and the amplification pattern in the tumor cell lines is representative of the fresh tumors obtained from the same patients.

Restriction fragment length polymorphism studies show consistent loss of chromosome 3p alleles in small cell lung cancer patients’ tumors. Johnson BE, Sakaguchi AY,GazdarAFetal.Na~ionalCancerlns?itute- Navy Medical Oncology Branch, Narianal Cancer Instilute and Naval Hospilal. Bethesda, MD 20814. J Clin Invest 1988;82:502-7.

Previous karyotypic analysis of human small cell lung cancer cell lines hasdemonstratedaconsistentdeletionofaportionoftheshortarm of chromosome 3@14-23). DNA prepared from tumors and normal tissues obtained from 24 small cell lung cancer and two extrapulmonary small cell cancer patients was hybridized to four probes that detect restriction fragment length polymorphisms within chromosome region 3~14-21. Of the 25 patients who were heterozygous for at least one marker in this region in the DNA from normal tissue, 23 (92%) showed an unequivocal loss of heterozygosity in the DNA from their tumor tissue. From these studies we conclude that loss of alleles from the short arm ofchromosome 3 isaconsistent finding in unselected small cell lung cancer patients’ tumor DNA.

A glycopeptide from adenocarcinoma tissue-of human lung. Masuda H, Ozeki T. ThirdDepartment ofInternal Medicine, University of Occupational and Environmental Health, School of Medicine. Yahalanishi-ku, Kitakyushu. Fukuoka 807. Biochem Med Metab Biol 1988;40: l-7.

A glycopeptide from adenocarcinoma tissue of human lung was extracted by protein digestion with papain and trypsin. This component was isolated by Pevikon block electrophoresis. It possessed hexose, glucosamine, fucose, galactosamine, and sialic acid. In its carbohydrate composition and also the abundance of threonin in the peptide moiety it was quite similar to the glycoprotein from gastrointestinaI tract. The physical characteristic of the two, such as their optical rotation and viscositv. were also very similar to each other.

Growth factor effects on small cell lung cancer cells using a colori- metric assay: Can a transferrin-like factor mediate autocrine growth? Nakanishi Y, Cut&a F, Kasprzyk PG et al. NCI-Navy Medical Oncol- ogy Branch, Naval Hospital, Bethesda. MD 20814. Exp Cell Biol 1988;56:74-85.

A semiautomated calorimetric assay @ITT assay), based on the ability of live cells to reduce a tetrazolium-based compound, 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MT-I’), to a purplish colored formazan product that can be measured spectro- photometrically, has recently been adapted for use in drug sensitivity analysis of cultured human tumor cell lines. We report the application of this assay for the evaluation of the growth factor requirements of humansmallcelllungcancer(SCLC)celllines.Specifically,thegrowth stimulation of each constituent of a previously reported serum-free defined medium system for SCLC including various concentrations of hydrocortisone, insulin, transfer&, 17B-estradiol, and selenium (HITES) was evaluated. The optimal concentrations for insulin, trans- ferrin, and selenium derived in the previously reportedexperiments with direct counting of viable cells were similar to optimal concentrations determined for the growth of three SCLC cell lines (NCI-H82. NCI- N417, NCI-H526) using the MTI assay. In contrast to the previous report, the growth-stimulating effects of hydrocortisone and 176estra- diol were negligible. Using the MTT we have been shown that a SCLC cell line, NCIH345 (which has been previously reported to produce a transferrin-like molecule), was growth-inhibited by an antitransferrin receptor antibody, when grown in transferrin-free media. The condi- tioned media from this cell line is stimulatory to other transferrin- sensitivecelllines,suggestingIhepossibilityofanau~rineroleforchis transferrin-likemoleculeat least in thatcellline. Withcarefullydefined conditionsforagivencelllinein whichcelldensityandotherparameters are within a range of constant MTI metabolism, the assay is well suited for precise analysis of growth factor effects.

Radiolaheled monoclonal antibody 15 and its fragment for locahzp- tion and imaging of xenografts of human lung cancer. Endo K, Kamma H, Ogata T. Departmenr of Surgery, InsrirrUe of Clinical Medicine, University of Tsukuba, Ibaraki 305. J Natl Cancer Inst 1988;80:835-42.

Monoclonal antibody (MAb) 15 and its F(ab’), and Fab fragments were radioiodinated, and their biodistribution and imaging were com- pared in BALB/c nude mice bearing a xenograft of a human lung cancer (TKB-2). Association constants for r”I-labeled MAb I5 IgG, F(ab’),, and Fab were 1.9 x 109, 1.8 x 109, and 3.7 x lb M-l, respectively.