37

intestine, and heart, but reactive with stomach cancer, breast cancer, and normal skin.

Enzyme treatment study showed the epi- tope recognized was polypeptide. SDS-PAGE and immunoblot analyses suggested the mo- lecular weight of the antigen was 34000.

This antibody may be useful in consi- dering the lineage patterns of human lung cancers.

Successful Preparation and Specificity Studies of Monoclonal Antibodies Against

Lung Adenocarcinoma. Wu, S.F., Ye, Q.W., Dai, H.M., Fang, J., Wang*, Ge*, X.R. Shanghai Chest Hospital and Shanghai Institute of Cell Biology, Academia Sinica*, China.

Fusion of the murine myeloma line NS-1 with spleen cells from BALB/C mice immu- nized with a human lung adenocarcinoma cell line (SPC-A-I) coated with antibodi- es against normal human lung tissues yiel- ded ten stable hybridoma monoclones that produce monoclonal antibodies which reac- ted by indirect immunofluorescence and Avidin Biotin Complex (ABC) assays with immunizing SPC-A-I cells and its trans- plant tissues of nude mice.

Two monoclonal antibodies, LAC-163 and LAC-210, were characterized by immuno- fluorescence on live cells from various tumor cell lines and by ABD on frozen sec- tions of different tumor tissues from sur- gical specimens, and of normal fetal or adult lung and other tissues.

The results obtained indicate that LAC- 163 and LAC-210 reacted and squamous cell carcinoma in both tissue and cell lines, but hardly showed cross-reaction with small cell lung carcinoma and other carcinoma of breast, stomach, colon, rectum, esopha- gus, maxillopalatine and thymoma as well as fetal and adult normal tissues. Those monoclonal antibodies also failed to re- act with various tumor cell lines of ton- gue, breast, malignant mesothelioma and

hepatoma.

Serological and Innnunohi~tochemical Stu- dies on Sialylated Lewis Antigen in Sera and Tissues from Lung Cancer Patients. Sugawara, Y., Nat~ri, H., Asakaw~, M., Su- zuki, A,, Yoshida ,,~., Kusajima** K., Komatsu **S., Iguro , T., Iwaki , Y., Terasaki , P.I. Dept. Med./Section 3. *Dept. Surg./Section 2. Sapporo Medical College, Sapporo, Japan. ** Dept. Surg. UCLA School of Med., University of Cali- fornia, Los Angeles, U.S.A.

In recent years numerous monoclonal antibodies against tumor-associated an- ticens have been identified. High titers of reverse passive hemagglutination (RPHA)

were noted in sera from lung cancer pa-

tients with a new monoclonal IgM antibody CSLEXI x

that can detect the sianylated Lewis antigen. Immunohistochemical studies of the sialylated

Lewis x antigen were carried out to determine the histological localization of this antigen in lung can- cer tissues, ee~ xe.~ with CSLU/ (128 ¢..e. o f fun B cancer)

T l t e r o f ~ l i t i v e sera Type ~ . N o . / ( + ) 32x-128x 2 5 6 x -

~ e n o c a r c i n o u 56 2b 18 8 Squa~us c e l l ca. 52 10 9 1 S u l l c e l l ca. 14 4 3 1 ~ r g e c e l l ca . 3 2 1 1 U n d i f f e r e n t l n ~ e d ca. 3 _- 1 1

In the immunohistochemical studies, the posi- tive rates were 70% (22/32) in adenocarcinoma and 15% (2/14) in squamous cell carcinoma. Two out of 6 preoperative sera from immunohistochemically positive adenocarcinoma patients, showed a posi- tive serological reaction. One serologically & immunohistochemically positive case, and five sero- logically & immunohistochemically negative cases were found among 6 cases of squamous cell carci-

noma. Serological and immunohistochemical analysis

suggested the sialylated Lewis x antigen to be a tumor-associated antigen in lung cancer, especi- ally in adenocarcinoma.

Monoclonal Antibodies (MoAbs) to Surface Antigens of Sm~ll Cell Lung Carcinoma (SCLC). I Reeye , J.G., Wulfrank , D.A., Stewart , J., Blee- hen-, N.M.i. MRC Clinical Oncology and Radiothe- rapeutics Unit, MRC Centre, Cambridge, U.K. 2. Department of Radiotherapy, University Hospital, Ghent, Belgium.

Intact SCLC cells from the lines NCI-H69 and the recently derived COR-L32 have been used to produce a panel of MoAbs directed against lung tumour cell surface antigens. These MoAbs were tested in radiobinding assays against 9 pulmona- ry, 6 non-pulmonary, 6 neuroectodermal and i0 o- ther human tumour cell lines. These analyses re- vealed that (a) lung tumour antigens can be divi- ded into those that are restricted to SCLC and those which are common to SCLC and non-small cell lung cancer; (b) while many ttunour cell lines fail to express the antigens, human melanoma and neuro- blastoma lines frequently did express certain SCLC antigens. Immunohistochemical assays revea- led that certain SCLC lung tumour antigens are expressed on brain, normal respiratory epithelium, proximal tubules of adult kidney and neuroendo- crine cells of the adrenal medulla, pancreas and colon.

The biological effect of these MoAbs on SCLC colony growth in vitro was determined using a semi solid agar growth assay. Compared to cells treated with an irrelevant MoAb, complete colony growth inhibition was obtained for SCLC cell lines FRE and POC with the anti-SCLC MoAbs studies, at culture supernatant dilutions of up to 1:40. The growth of HeLa (cervical carcinoma) cells and T278 (osteogenic sarcoma) cells was unaffected by the MoAbs even after treatment with undiluted superna- tants. The anti-proliferative effect of these MoAbs therefore appears to be dependent upon specific antigen binding and may indicate a therapeutic