George D. Sorenson

Hormone production by cultures of small-cell carcinoma of the lung.

Continuous cell lines have been established from a variety of biopsy and postmortem species of tumor from patients with small‐cell carcinoma of the lung (SCCL) and have been maintained over several years. The medium from the cultures has been assayed for peptide, glycoprotein, and steroid hormones. Significant amounts of 14 hormones including calcitonin, adrenocorticotropin (ACTH), parathormone, luteinizing hormone, chorionic gonadotropin, glucagon, growth hormone, somatostatin, prolactin, β‐endorpin, lipotropin, oxytocin‐neurophysin, vasopressin‐neurophysin, and estradiol have been demonstrated. Up to ten different hormones have been produced by a single cell line. Most produce ACTH and all evaluated so far produce estradiol. These studies indicate that cells from SCCL have a potential for producing a wide variety of hormones and that this characteristic can be maintained for prolonged periods of culture in vitro.

Isolation and growth characteristics of continuous cell lines from small-cell carcinoma of the lung

Sixteen continuous tumor‐cell cultures have been isolated from 91 tissue specimens from patients with small‐cell carcinoma of the lung. Biopsy and autopsy specimens of primary and metastatic tumors have been utilized. The developing cell lines were recognized by proliferation of tumor cells in the culture from one to 14 weeks after explantation and have been maintained for up to four years. Primary lung tumor, bone marrow aspirations, pleural effusions and other metastases have all been productive explant material for the development of cell lines. Their human origin has been demonstrated by chromosome and/or isoenzyme analysis. Dense core vesicles, characteristically found in small‐cell tumor cells were observed by electron microscopic examination of cultured cells. Growth rates in vitro have been measured and the in vitro cycle time in tumors of one cell line (DMS 79) has been compared with in vivo cycle time in tumors arising from DMS 79 cells in nude athymic mice.

Bombesin production by human small cell carcinoma of the lung

A series of continuous cell lines of human small cell carcinoma of the lung (SCCL) have been evaluated for the production of bombesin (BN). In early established cultures BN was detected in the medium of 9 out of 11 cell lines and in 6 out of 7 cell homogenates examined. Levels in the medium were frequently higher in cultures of later passages compared to earlier passages of the same line and low levels developed in the two previously negative cell lines. Plasma concentrations were greater than 80 pmol/l in 2 out of 27 (7%) randomly selected patients with SCCL. A culture (DMS 406) established from the tumor of a patient with the highest plasma level (1240 pmol/l) was the highest producer in vitro. The results indicate that BN, which has been demonstrated immunocytochemically to be present in normal bronchial mucosal cells, is frequently produced by SCCL in vitro but elevated plasma levels are infrequently found in patients with this neoplasm.

Cytogenetics of small cell carcinoma of the lung

Nineteen cell lines derived from various malignant tissues of 15 patients with small cell carcinoma of the lung (SCCL) have been studied. The results showed heterogeneity in all cell lines, with no one consistent abnormality among them. Cell lines from 11 of the patients had minute and double minute chromosomes, and cell lines from 2 patients had abnormally banding regions, designated as ABRs, as distinguished from homogeneously staining regions (HSRs). The latter 2 and several of the former cell lines were derived from specimens taken before the patients were placed on therapy. All but 2 of the cell lines had a constant marker load, consisting of 24%-35% of the complement. Some markers remained stable through months and years of culture life, while other markers came and went. Chromosomes #1, #6 and #11 were most frequently involved in marker formation in the cell lines, and these were compared to similar markers in direct bone marrow preparations. Chromosome #1 markers were of variable structure, whereas #6 and #11 most often took the form of 6q- and 11p+ markers, with breakpoints most frequently at 6q23-25 and 11p11-12. A 3p- marker was found in a minority of cell lines. All of these markers were also found in direct marrow preparations from some patients with SCCL. Nonmonoclonal tumors arose from inoculation of bimodal cell lines into nude mice, but population selection by undetermined mechanism was evident. Cytogenetic parameters showed no positive correlation with hormone production by these cell lines.

Bombesin and calcitonin secretion by pulmonary carcinoma is modulated by cholinergic receptors

Three established cell lines derived from human small cell carcinoma of the lung, and known to produce significant amounts of peptide hormones were used to evaluate the regulation of hormone secretion by cholinergic agonists. In two of the cell lines (DMS 53, DMS 153) acetylcholine chloride, bethanechol chloride, and carbamylcholine at the concentrations of 10(-3)M to 10(-5)M stimulated secretion of bombesin and calcitonin as measured by RIA. The third cell line, DMS 406, was not significantly stimulated. Inhibition of induced stimulation by the cholinergic antagonist atropine, but not hexamethonium, indicated the presence of muscarinic rather than the nicotinic type of cholinergic receptors on the stimulatable cells. These receptors appear to mediate hormone secretion comparably to normal endocrine cells.

Giemsa-banded chromosomes of mouse myeloma in relationship to oncogenicity.

G-banded karyotypes (413 in all) of the hypotetraploid mouse myeloma MOPC-21 and five cell lines isolated at different times, of the MOPC-315 tumor and a cell line, and of the X5563 tumor were compare

Mapping and characterization of an X-linked processed gene related to MYCL1

A DNA sequence with homology to the myc family of proto-oncogenes has been characterized and found to be a processed gene related to L-MYC (MYCL1). This processed gene (MYCL2) was isolated by cross-hybridization to an oligonucleotide probe synthesized from the C-MYC (MYC) sequence in a highly conserved region of the myc gene family. Sequence analysis of MYCL2 revealed an open reading frame of 1194 bp with no intervening sequences and strong homology to the recently published DNA sequence of MYCL1. Southern and Northern blot analyses of DNAs and RNAs from small cell lung carcinomas confirmed its MYCL1 homology. Mapping of MYCL2 by somatic cell hybrids places this sequence on the long arm of the X chromosome in bands q22----q28.

Lysis of small cell carcinoma of the lung tumor cell lines by gamma interferon-activated allogeneic peripheral blood mononuclear cells: abrogation of killing by pretreatment of tumor cells with gamma interferon

SummaryInterferon has been shown to enhance the ability of nonspecific cytotoxic mononuclear cells to lyse some, but not all, tumor cells. We have examined the effect of recombinant human gamma interferon (rIFNγ) on the cell-mediated cytolysis of tumor target cells derived from continuously cultured lines of small cell carcinoma of the lung (SCCL). Cells from the SCCL lines DMS 44, 53, 79, 92, and 406 were labeled with 51Cr and incubated with normal and rIFNγ-stimulated peripheral blood mononuclear cells for 18 h at 37 °C and tumor cell lysis estimated by measuring 51Cr release. Although cells from certain SCCL lines were good targets for cell mediated cytotoxicity, susceptibility to lysis was heterogenous among the different SCCL lines. DMS 406 and 79 were, on average, maximally lysed, while DMS 44, 53, and 92 showed less susceptibility to lysis by either control or rIFNγ-stimulated effector cells. In addition, although pretreatment with rIFNγ increased the cytolytic capacity of normal peripheral blood mononuclear cells from several different donors, preincubation of the tumor cell lines with rIFNγ resulted in inhibition of cytolysis mediated by both control and IFN-activated effector cells. These findings suggest that although rIFNγ may enhance cell-mediated lysis of SCCL tumor cells, it may also decrease susceptibility to lysis.

Biogenic amine metabolites in human lung tumor cells: Histochemical and mass-spectrographic demonstration

Three continuous cell lines isolated from small cell carcinoma of the lung (SCCL) have been examined for their ability to take up and metabolize the biogenic amine precursors, L-DOPA and 5-hydroxytryptophane (5-HTP). In two of the three lines formaldehyde-induced fluorescence (FIF) and mass-spectrographic analysis indicated specific uptake and metabolism of L-DOPA and 5-HTP.

Immunocytochemical staining of cytocentrifuge prepared cultured cells: nonspecific staining and its elimination

SummaryIn an attempt to localize hormones in cytocentrifuge-prepared cultured cells of small cell carcinoma of the lung (SCCL), various modifications of the immunoperoxidase (PAP) procedure (Sternberger, 1979) were tested. When using glutaraldehyde, formaldehyde, orp-benzoquinone fixation (Pearse & Polak, 1975) and rabbit antibodies in primary or bridging steps of the PAP procedure, nonspecific staining (false positives) could be elicited with the majority of rabbit antibodies tested, but not with antibodies from other animal sources. This problem could be eliminated by fixation of cells either with formalin-acetone (Masonet al., 1975) or, when using antibodies from a source other than rabbit, glutaraldehyde. It was not possible to localize ACTH in DMS-79, a human SCCL line known to produce this hormone. However, calcitonin was localized in the calcitonin-producing SCCL line DMS-53. Failure to localize ACTH in DMS-79 may be due to the lower levels of this hormone in DMS-79, as compared to the levels of calcitonin in DMS-53. This study emphasizes the importance of proper controls before concluding successful localization in a given immunocytochemical preparation of cultured cells.