4th LTBW Abstracts/ Lung Cancer 10 (1994) 347-373 359

specific sites within the regulatory region of the AHH encoding CYPlAl gene. The mutated sequences were cloned into a chloramphenicol acetyltransferase (CAT) reporter gene vector and the constructs were introduced into the cells to produce stably transfected cell lines. Reporter gene expression was in- duced by the addition of 10 nM TCDD (2,3,7,8-tetrachloro- dibenzo[p]dioxin), a potent inducer of CYPIAI gene expres- sion. Levels of the CAT gene product were measured in the cell lines by an ELISA-based assay. The cell lines used in this study all exhibited elevated basal levels of CAT gene expression that were only slightly increased in the presence of inducer. To date, we have identified two sites within the regulatory region of the human CYPlAl gene that are responsible for the elevated basal level of expression observed in two of the cell lines under study. In both cell lines, alteration of either of the two sites results in a significant decrease in the level of reporter gene expression. Simultaneous alteration of both sites results in complete loss of expression of the reporter gene. The patterns of reporter gene expression observed in the mutants were consistent with those that are predicted for the altered interaction of one or more trans-acting factors with the regulatory region of the CYPIAI gene. In contrast to what has previously been proposed, no pat- terns that could be attributed to c&acting effects, either within the regulatory region or the AHH coding region, were observed. Further investigation may permit us to develop mo- lecular screening tools for the identification of increased risk for the development of lung cancer.

clinical complete response to a murine moaoclonal antibody (2All) directed against gastrin releasing peptide in a patient with small cell lung cancer Kelley MJ, Avis I, Linnoila RI, Richardson G, Snider R, Phares J, Ashbum R, Laskin WB, Becker K, Boland C, Cuttit- ta F, Mulshine J, Johnson BE. NCI-Navy Medical Oncology Branch, and Biomarkers and Prevenfion Research Branch, Na- tional Cancer Institute. Bethesda, MD; Veterans Affairs Medical Cenier, Washington, DC: National Naval Medical Center. Bethesda, MD.

Gastrin releasing peptide (GRP) is an autocrine growth factor for small cell lung cancer (SCLC) [ 11. Interruption of this autocrine growth factor loop by the murine monoclonal anti- body, 2A11, has been shown to have anti-tumor activity in vivo and in athymic nude mice [l]. In order to determine the clinical utility of interruption of growth factor stimulation in SCLC, we examined the activity of 2All (250 mg/m*, three doses/week for 4 weeks) in 12 patients with SCLC in a Phase II trial. Prior treatment included at least one cisplatin-containing regimen for all patients. The median age was 57 years (range 44-69). There were nine males and three females. The performance status was 0 (n = l), 1 (n = lo), or 2 (n = 1). One of these twelve patients (8%) had a clinical complete response documented by chest X- ray, chest CT scan and by direct bronchoscopic visualization; four had stable disease, six had progressive disease, and one was not evaluable. There was no toxicity and clinically signifi- cant human anti-mouse antibody (HAMA) did not develop. The completely responding patient was a 6S-year-old female who had isolated lung recurrence after a 3.5year disease-free interval following initial treatment with combined chemother-

apy and radiotherapy for limited stage SCLC. Bronchoscopic biopsy at the time of clinical complete response suggested small cell carcinoma but was inconclusive due to scant amount of tumor and crush artifact. She was treated with a second course of 2A11 and maintained a CR for 4.5 months at which time she had local recurrence documented by bronchoscopy. The pt was still free of immunologic evidence of HAMA but her tumor progressed at the site of the initial recurrence despite a third course of 2All. Immunohistochemistry using 2All failed to reveal GRP staining in this patient’s pre-treatment and post- treatment tumor biopsies. The median pre-treatment serum GRP level of 11 patients on this study determined by RIA using a polyclonal anti-GRP antiserum was 21 pg/ml (range < 3 to 83). The completely responding patient’s pre-treatment serum GRP was 9 pg/ml. Urine obtained prior to initial chemotherapy had a GRP level of 38 pg/mg of urine creatinine in the com- pletely responding patient and 125 and 27 pg/mg of urine creatinine in two non-responding patients. We conclude that: (i) 2All has clinical antitumor activity; (ii) treatment with 2A11 is non-toxic; (iii) sustained treatment is possible without the development of clinically significant HAMA; and (iv) tumor response to 2Al1 is not predicted by pre-treatment se- rum or urine GRP levels as measured by a polyclonal anti- serum. Further evaluation of the clinical efficacy of 2All continues with emphasis on the identification of tumor characteristics, such as the presence of receptors for GRP, that predict for response to 2A11.

Malignancy associated changes in broachial epithelial cells Lam S, MacAulay C, Payne PW,, Palcic B. Cancer Imaging, Medical Physics Division, British Columbia Cancer Agency Vancouver, Briiish Columbia, Canada VSZ 4E6.

Sputum cytology is the only non-invasive method that can detect pre-malignant lesions or carcinoma in situ in the tracheobronchial tree. Unfortunately the yield of sputum of cytology is low. In a study at Johns Hopkins, among 5226 subjects, 233 of them were found to have lung cancer over a 6- to 9-year period. Initial sputum cytology examination detected 11 cancers or approximately 5% of those who developed lung cancer. Marked or moderately dyskaryotic cells were found in another 3.5%. In the 183 subjects with suspicious sputum cytology, the probability of developing cancer varied between 40% in those with marked atypia to 10% in those with moderate atypia. Even if immuno-staining techniques directed towards differentiation markers on the cell surface can help to predict which of the subjects with atypical bronchial epithelial cells would develop cancer, we can at best detect 15% of the subjects who would develop lung cancer. Clearly, there is a need to im- prove the sensitivity and specificity of sputum cytology to detect lung cancer.

To approach this problem, quantitative microscopy was used to measure quantitative features of bronchial epithehal cell nu- clei that have been stained with a quantitative DNA stain (Thionin-SO*). A large number of features are calculated for each nucleus, including textural features which measure the spatial distribution of DNA in the nucleus. It has been shown that normal cells growing in the vicinity of pre-malignant le-