189

of the presence of the polymorphtc EcoRI restriction site m the second mtron of the L-myc proto-oncogene. These datacmphasize the impor- tanceofconductingeptdemiologic studiesthatcontrol forethnicfactors and mdnzate that L-myc EcoRI allelotypes do not appear to bc predic- t~veoflungcancerriskord~seasestatus m Amertcan blacksand whites.

Increase of epidermalgrowth factor receptor expression associated with a lack ofantiproliferative effect of IFN-B in human lung cancer nodules in organotypic culture Martyre MC, Grimaux M, Beaupain R. Laboratoire d’lmmunopharma-

cologieExperwnentale. oil CNRS579,Paris. TumorBml1990;11:202- 9.

The possible relationship between the effects of a>-, B- and gamma- inlerferons (IFNs) on the growth of alveolar II pulmonary tumor cells (A549) maintained in tridimensional organotypic culture (nodules) and the modulation of epidermal growth factor receptor (EGFR) expression was invcsugated. Treatment with rHu IFN-a, or IFN-gamma which results in the inhibition of the growth of A549 nodules had no effect on the binding of ‘=‘I-EGF to these cells. In contrast, treatment with rHu IFN-B which exhibits no antiproliferative activity on A549 nodules resulted in a reproducible increase of the binding of ‘“sI-EGF. Scatchard analysis of the EGF binding data indicated that a 4%hour exposure period resulted in an increase in the apparent number of cells surface EGF-R but did not significantly alter receptor affinity. Results from Northern blot analysis showed that the enhanced expresston of EGF-R on the A549 nodule cells treated with IFN-l3 correlates with an increase m mRNA for EGFR. No modification of the EGF-R mRNA expression was observed in nodules treated with IFN-a, or IFN-gamma. In this model, our results suggest a relationship between resistance to antipro- lifcrative effect of IFN-!3 and modulation of EGF-R.

SelectivecytotoxiceffectsofaricinAchainimmunotoxinmadewith the monoclonal antibody SWAll recognising a human small cell lung cancer antigen Wawrzynczak EJ, Dcrbyshrre EJ, Henry RV et al. Drug Targeting

Laboratory. Section ojhledtcine. Institute ofCancer Research. Sutton

SM2 SNG. Br J Cancer 1990;62:410-4. The potential of mouse monoclonal antibodies for recognising differ-

cnt antigens associated with human small cell lung cancer (SCLC) to form active immunotoxins was assessed by an indirect in vitro screen- mg assay. The screening agent used was a conjugate made by linking ricin A chain to a sheep anti-mouse IgG Fab’ fragment via a disulphide bond. The monoclonal antibodies SWAI 1 and SWAZO both mediated the toxtceffcctsofricin Achain agamst the HClZclassic SCLCcell line m dose-dependent fashion. The SWAll antibody was the more effec- uve; in combination with the screening agent at a concentration of 1 x IO-? M, it inhibited the incorporation of [‘HI leucine into HC12 cells by 94% compared with only 44% inhibition m the case of SWA20. An immunotoxm made by the direct chemical conjugalton of ncin A chain to SWAl I exhibited selective toxic effects upon HC12 cells in tissue culture Inhibiting the incorporation of [?H] leucine by 50% at a concen- tration (ICsO) of6.2 x 10l”M and by 98% at 1 x IO-‘M. SWAI I-ticin A chain hadan IC,,of4.4 x 10-‘OMagainst theNCI-H69classic SCLC cell line but showed no cytotoxic activity against the human lung ade- nomacarcinoma cell line NCI-H23 at a concentration of I x 10-8M.

Frequent amplification of the bcl-l locus in poorly differentiated squamous cell carcinoma of the lung Berenson JR, Koga H, Yang J, Pearl J, Holmes EC, Fighn R. Depart-

ment of Medicine, Center for the Ilealth Sciences, UCLA School of

Medrcine, 10833 Le Conte Avenue, Los Angeles. CA 90024. Oncogene

1990;5:1343-8.

The bcl- I locus on chromosome 1 I at band q13 has been shown to be rearranged in some chronic B lymphoid malignancies with the t(1 l;14) (ql3;q32). Chromosome 1 I abnormalities occur in solid tumors includ- mg squamous cell cancers and adcnocarcinomas. We have recently reported the frequency amplification of the bcl- 1 locus in squamous cell carcinomas of head and neck origin, and increased copy number also has been found in some breast adenocarcinomas. In this investigation, we analyzed the arrangement, copy number and expression of this locus

in 111 primary non-small cell lung cancers. Bcl-I was found to be amplified three- to IO-fold in seven fresh tumors. Whereas none of 51 adenocarcinomas showed bcl-1 amplification, six of 46 squamous cell carcinomas rcvcaled an increase m bc- 1 copy number. This amplifica- lion was more frequently associated with larger and more poorly differcntiatcd tumors. None of the cancers showed rearrangement of this locus.

Photosensitizing dyes for the selection of nontumorigenic rever- tants from human lung cancer cell lines McDonald JW, Brash DE, Oseroff AR, Harrts CC. Laboratory of

ffuuman Carctnogenesis, Natonal Cancer Institute, NIH, Building 37,

Room 2COI, 9000 Rockviile Pike, Bethesda. MD 20892 Cancer Res 1990;50:5369-73.

Certain positively charged, hpoplnhc dyes have been noted by variousauthors tolocalizesekxxrvely m the mitochondriaofcarcinoma cells. Oseroff et al. (Proc. Natl. Acad. Sci. USA, 83:9729-9733, 1986) studied 10 carcinoma-specific mitochondrlal photosensitizers and judged N,N’-bis(2-ethyl-1.3~dioxolane)kryptocyanine (EDKC) to be the most effective in selective carcinoma cell photolysn. a system where light- absorbing molecules accumulate only in carcinoma cells and on illumi- nation imtiate a reaction that kills or damages those cells. The present study duplicated the published EDKC retention result for the normal monkey kidney cpithclial cell line CV- I. A serlcs of nontumorigenic and tumorigcnic human bronchial epithelial and human pleural meso- thelial cells were assayed for EDKC uptake and retention, with the intent of using selective carcinoma cell photolysis to isolate nontumo- rigemc revertants of the tumorigenic lung cell lines. In addition, the uptake and retention of the fluorescent, mitochondria- and carcinoma- specific dye rhodamine- were surveyed in a series of hybrids between tumorigenic and nontumorigemc human bronchial epithelial cells. The half-life of dye retention ranged from 6 to 12 h in all the bronchlal epitheltal and mesothelial cells studted, with little or no dye selectrvity for tumorigcnic cells. When EDKC-retainmg bronchial epithelial cells were illuminated wtth red light, stgnificant reductions in short term viability and colony-forming effictcncy were seen, which bccamc more pronounced as light and dye doses were increased. However, these effects did not correlate with tumorlgenicity within the cell series. The method, therefore, does not appear generally useful for the selection of nontumorigemc vartants of human bronchial ep&elial or pleural mesothelial cancers of the lung.

Effect of guanine and adenine nucleotides on bombesin-stimulated phospholipase C activity in membranes from Swiss 3T3 and small cell lung carcinoma cells Sharoni Y, Viallet J, Trepcl JB, Sausvdle EA. NCI-Navy Medical

Oncology Branch, National Cancer Insritute, NISI. 9000 Rockville

Pike, Bethesda. MD 20892. Cancer Res 1990;50:5257-62.

In [3H]inositol-labeled membranes prepared from Swiss mouse 3T3 and human small cell lung carcinoma cells, [Tyti]-bombesin stimulated productton of water-soluble inositol phosphates. The reaction was stimulated by guanosine5’-O-[3-thiotriphosphate] and was specilically Inhibited by both [Leu”-psi-CH,NHLeu’4]-bombesin and the anti- bombesin antibody 2All. [Tyti]-bombesm-Induced activation of phospholipase C is most apparent in Ca2+-depleted conditions (<I pM[Ca”](frce)]. The kinetics of activation by ligand also demonstrate that [Tyfl]-bombesin-dependent phospholipase C activation is most apparent at [Mg”+](free) of -0.2 pM. At millimolar concentratmns of [Mg*‘](free), thereisconsiderably lessdependenceon [Tyr’l-bombesin for activation of phospholipase C. ATP is not necessary for initial activation of phospholipase C, and &gamma-imidoadenosine-5’. uiphosphatc does no1 inhabit the reaction. These resul& demonstrate that in these cell types ]TyP]-bombesin activates phospholipase C In

conjunction with guanine nucleotides. Phospholipase C-coupled gua- nine nucleotide regulatory proteins would be appropriately considered as novel targets for the development of therapeutic strategies in small cell lung carcinoma.

lsoehromosome (8q) in four patients with adenocarcinoma of the lung Miura I, Resau I, Tomiyasu T, Testa JR. Secrion ofMolecular Cyrogen-