(CANCER RESEARCH 48. 3140-3147. June I. 1988] Profiles of Prostaglandin Biosynthesis in Normal Lung and Tumor Tissue from Lung Cancer Patients Theodore L. McLemore,1 Walter C. Hubbard, Charles L. Litterst, Mark C. Liu, Stephan Miller, Noreen A. McMahon, Joseph C. Eggleston, and Michael R. Boyd Program Research and Development Group, Office of the Associate Division Director for Developmental Therapeutics, Division of Cancer Treatment, National Cancer Institute—Frederick Cancer Research Facility, Frederick, Maryland 21701 ¡T.L. M., W. C. H., C. L. L., M. K. B.J,and Departments of Medicine (Pulmonary Division) and Surgical Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 [M. C. L., S. M.,N. A. M.,J. C. E.J ABSTRACT Prostaglandin (PC) biosynthetic profiles from endogenous arachidonic acid were determined by capillary gas chromatography-mass spectrome- try in matched fresh normal lung (NL) and lung cancer (LC) tissue fragments obtained from 42 individual LC patients at the time of diag nostic thoracotomy. The histológica!diagnoses represented were squa- mous cell carcinoma (/V = 20), adenocarcinoma (/V = 7), small cell carcinoma ( V = 4), mixed cell carcinoma (.V = 2), bronchioloalveolar cell carcinoma (.V = 2), large cell undifferentiated carcinoma (/V = 3), bronchial carcinoid ( V = 1), and metastatic tumors (A/ = 3). When PG biosynthesis was determined in NL tissue separately, low mean levels of PGEj and PGFi, (<2 pmol/mg protein/15 min), intermediate levels of PGD2 and 6-keto-PGF,,, (6KPGF,.) (2-7 pmol/mg protein/15 min), and high levels of thromboxane B2(TXB2) (>7 pmol/mg protein/15 min) were observed. There was no particular correlation with cigarette smoking history and PG biosynthesis in NL. When PG production in LC tissue was evaluated separately, high levels of !'(.!'. I'M-.., and 6K1'(,I ,., as well as I \H.. and low levels of PGD2 were noted. In addition, LC tissue from cigarette smokers demonstrated elevated levels of PGE2, 6K I'M-',.,, and IAlt., when compared to current nonsmokers with LC (/' < 0.05 in all instances). Simultaneous comparison of PG production in matched LC and NL tissue from individual patients indicated increased biosyn thesis of 1'Mv. and I'M-'..., and low levels of PGD2 in LC compared to NL tissue (/' < 0.05 in all instances; paired, two-tailed. Student's t test). Individual comparison of PG biosynthesis according to LC histological cell type revealed that I'M , and PGF&, were consistently elevated in all four common primary LC histological cell types, the only exception being large cell undifferentiated carcinoma. Interestingly, this latter LC histo logical cell type presented a unique profile with lower levels of I'M- . and I'M)., in LC than in NL tissue (/' < 0.05 in both instances). In addition, the biosynthesis of all 5 PGs studied was consistently higher in primary than metastatic adenocarcinomas of the lung (/' < 0.05 in all instances). No differences were observed in NL and LC tissue for the major LC histological cell types when I'M »... IAB , or hkl'M ,. biosyntheses were compared. These findings indicate that the profiles of PG biosynthesis in LC and NL tissue from individual patients may differ substantially. These differences may reflect, in part, contributions to the PG biosyn thetic profile unique to malignant cells. INTRODUCTION Pulmonary carcinomas are a major cause of adult morbidity and mortality in the United States population (1-5). A more detailed understanding of the biochemistry of human LC2 could contribute to the further development and refinement of better approaches to earlier, more specific diagnoses as well as poten tially lead to improvements in the therapeutic intervention and treatment of this disease. Studies characterizing human lung carcinomas according to selected neuroendocrine and cellular properties have provided valuable initial information regarding Received 11/18/87; revised 2/26/88; accepted 3/4/88. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. 1To whom requests for reprints should be addressed, at NCI-FCRF, Bldg. 428, Rm. 63, Frederick, MD 21701. :The abbreviations used are: LC, lung cancer; NL. normal lung; PC, prosta- glandin; TX, thromboxane; 6KPGF,„,6-keto-PGF,„. certain biochemical features of pulmonary tumors, particularly small cell carcinomas (see Refs. 6-9 for review). The PGs and related eicosanoids are important mediators of NL function (10-12) and might also be important in the pathophysiology of certain human LC (13-17). Since the lung is a tissue rich in enzymes that biosynthesize PGs and TX as well as inactivate these compounds (18-23) the biosynthetic capability of lung tumor tissue to synthesize this family of compounds might be useful in the classification of LC and provide a more complete understanding of the role of PG and TX in the pathophysiology of this disease (13-17, 24-49). There is little information currently available regarding the profiles of 20-carbon fatty acid cyclooxygenase products in either NL or LC tissue. In the present studies, the profiles of five such products synthesized from endogenous arachidonic acid in matched NL and LC tissue from individual patients representing several histological classes of human LC were simultaneously compared. MATERIALS AND METHODS Study Subjects. LC and NL tissue were obtained at the time of diagnostic thoracotomy at the Johns Hopkins University School of Medicine from 42 LC patients (23 males and 19 females). A summary of the pertinent clinical information for these patients is provided in Table I. Ninety-three % (39 of 42) of the subjects had presented initially with primary lung tumors. The histological classification of both pri mary and metastatic LC is provided in Table 2. Collection, Preparation, and Incubation of Tissue Fragments. Proce dures for tissue collection, preparation for experimentation, and incu bation for PG from endogenous precursor in vitro are identical to those described previously (50). Triplicate specimens of biopsy fragments of NL and LC tissues were used for determinations of intersample varia tions of PG biosynthesis in the tissues studied. PG Analysis. The profiles of PGF2„, PGD2, PGE2, TXB2, 6KPGF,,,, and the 15-keto-13,14-dihydrometabolites of PGE2, PGF2„, 6KPGF,,, synthesized from endogenous arachidonic acid were performed via capillary gas chromatography-mass spectrometry as described previ ously (50). This method of analysis offers a very high degree of selec tivity, sensitivity (detection limits -0.1 pg of individual analyte per injection), and reproducibility. RESULTS Reproducibility of PG Measurements in Human Lung Biopsy Fragments Capillary gas chromatography-mass spectrometry measure ments of PG synthesized in biopsy fragments of NL tissue and lung carcinoma tissue have been demonstrated previously to be highly reproducible with coefficients of intrasample variations ranging from 2.2 to 18.5% (50). The cellular heterogeneity of NL tissue and LC tissue may contribute significantly to varia tions in the quantitative and qualitative profiles of PG synthe sized in these tissues. Examples of the variability of PG pro duction in triplicate samples of biopsy fragments of tissues (NL 3140 Research. on November 10, 2015. © 1988 American Association for Cancer cancerres.aacrjournals.org Downloaded from