Undifferentiated Carcinoma Of Lung Research Articles

V-Ha-ras oncogene insertion: a model for tumor progression of human small cell lung cancer.

Small cell lung cancer (SCLC) manifests a range of phenotypes in culture that may be important in understanding its relationship to non-SCLCs and to tumor progression events in patients. Most SCLC-derived cell lines, termed "classic" SCLC lines, have properties similar to SCLC tumors in patients, including high expression of neuroendocrine markers and low c-myc oncogene expression. A significant number of SCLC lines characterized as "biochemical or morphologic variant" SCLC lines have decreased levels of endocrine differentiation markers associated with increased proliferative indices, amplification of the c-myc oncogene, and growth patterns and biochemical markers more typical of non-SCLCs. To delineate further the relationships between these phenotypes and the molecular events involved, we have inserted the v-Ha-ras gene in SCLC cell lines with (biochemical variant) and without (classic) an amplified c-myc gene. These two SCLC subtypes had markedly different phenotypic responses to similar levels of expression of v-Ha-ras RNA. No biochemical or morphologic changes were observed in classic SCLC cells. In contrast, in biochemical variant SCLC cells, v-Ha-ras expression induced features typical of large cell undifferentiated lung carcinoma, including adherent monolayer growth patterns, increased cloning efficiency, increased levels of non-SCLC cell markers, ultrastructural characteristics and an acquired resistance to polyamine depletion typical of large cell carcinoma, but not SCLC, in vitro. Expression of v-Ha-ras in biochemical variant SCLC cells directly demonstrates that important transitions can occur between phenotypes of human lung cancer cells and that these may play a critical role in tumor progression events in patients. The findings provide a model system to study molecular events involved in tumor progression steps within a series of related tumor types.

Comparison of the effects of treatment with the polyamine analogue N1,N8bis(ethyl)spermidine (BESpd) or difluoromethylornithine (DFMO) on the topoisomerase II mediated formation of 4′-(9-acridinylamino) methanesulfon-m-anisidide (m-AMSA) induced cleavable complex in the human lung carcinoma line NCI H157

The positively charged polyamines putrescine, spermidine, and spermine are thought to be important in the maintenance of chromosomal structure. Polyamine depletion by the ornithine decarboxylase inhibitor, 2-difluoromethyl-ornithine (DFMO) is known to alter the effect of several DNA active agents, presumably resulting from the altered conformation of the polyamine depleted DNa. Here we compare the polyamine depletion effects of DFMO and the spermidine analogue N1,N8 bis(ethyl)spermidine (BESpd) on the formation of Topoisomerase II mediated, 4′-(9-acridinylamino) methane-sulfon-m-anisidide (m-AMSA) induced cleavable complex formation in human large cell undifferentiated lung carcinoma NCI H157 cells. This human cell line responds in the normal cytostatic manner to DFMO, whereas it responds in an unusual cytotoxic manner to treatment with BESpd. Here we report that neither DFMO nor BESpd alone affects the formation of cleavable complex. However, both compounds significantly enhance the m-AMSA induced formation of cleavable complex, each by approximately 1.6 fold. These results indicate that both DFMO and BESpd lead to a similar depletion of nuclear polyamines. Additionally, although BESpd closely resembles the natural polyamine spermidine, it appears that it cannot substitute for Spd at the level of DNA.

Immunohistochemical demonstration of phosphorylated and nonphosphorylated forms of human neurofilament subunits in human pulmonary carcinoids

Using immunohistochemical tests and monoclonal antibodies specific for phosphorylated isoforms of the high-molecular-weight human neurofilament subunit (NF-H) or for nonphosphorylated isoforms of NF-H and the middle-molecular-weight NF protein, we detected phosphorylated and nonphosphorylated NF protein isoforms in typical central bronchial carcinoids but not in atypical or peripheral carcinoids or in small cell undifferentiated carcinomas of the lung. Immunoreactive NF protein was seen largely in juxtanuclear globular aggregates which may correspond to cytoplasmic whorls of intermediate filaments observed in one of the tumors by electron microscopy. A monoclonal antibody to low-molecular-weight keratin polypeptides immunostained similar aggregates in central bronchial carcinoids. The precursor cells of human pulmonary carcinoids and the mechanisms leading to abnormal aggregates of NF and keratin immunoreactivity are unknown. However, the preponderance of phosphorylated NF epitopes as compared with nonphosphorylated forms in the cell bodies of carcinoid tumor cells implicates abnormal phosphorylation states in the formation of these intermediate filament aggregates. Our data do not confirm that antibodies to NF-H are helpful for the diagnosis of undifferentiated lung carcinomas, but they can distinguish subsets of bronchial carcinoids with different biological behaviors and growth potentials.

Murine monoclonal antibody LAM2 defines cell membrane determinant with preferential expression on human lung small-cell carcinoma and squamous-cell carcinomas.

Murine monoclonal antibodies (MAbs) were generated against a human undifferentiated lung carcinoma cell line. The hybridoma designated LAM2 produced an IgM kappa MAb with reactivity to the cell membrane. Indirect immunofluorescence staining and radioimmunoassay showed LAM2 antibody to react preferentially with lung small-cell carcinoma (SCC) cell lines and squamous-cell carcinoma (SQC) cell lines. LAM2 antibody also stained primary cultures of normal bronchial epithelial cells, but was unreactive with human erythrocytes and nucleated marrow cells. Indirect immunofluorescent staining with LAM2 antibody was performed on frozen sections of human tumor tissues and normal tissues. LAM2 antibody stained all 8 SCC carcinomas, 4 of 5 SQC of the lung and head and neck region, and 2 or 4 lung large-cell carcinomas. No staining was seen on lung adenocarcinomas, breast carcinomas, ovarian carcinomas, renal cell carcinomas, colon carcinomas, or mesotheliomas. Staining was present on sections of normal bronchus, but not on normal lung parenchyma, liver, kidney, adrenal or skin. While LAM2 antibody was highly reactive with all SCC examined, its antigenic determinant was not expressed in other cell lines and tumors of presumed neuroectodermal origin, including neuroblastoma, melanoma, and bronchial carcinoid. Radioimmunoprecipitation showed the antigen defined by LAM2 antibody to have two major bands of approximate molecular weights of 45,000 and 125,000. The selective reactivity of LAM2 antibody with SCC and SQC, but not with most other tumor tissues and normal tissues, makes it a good candidate for use in clinical diagnosis and possibly serotherapy.

A unique cell-surface protein phenotype distinguishes human small-cell from non-small-cell lung cancer.

We have used radioiodination (125I) and two-dimensional polyacrylamide gel electrophoresis to determine that small- (oat) cell lung carcinoma (SCC)--a tumor with neuroendocrine features--possesses a surface protein pattern distinct from the other types of lung cancer cells (squamous, adeno-, and large-cell undifferentiated carcinoma). Twelve distinguishing proteins, 40 to 70 kilodaltons (kDal), characterized four separate lines of SCC; three of these, designated E (60 kDal; pI = 7.3), S (30 kDal; pI = 6.0), and U (57 kDal; pI = 5.6), may be unique SCC gene products and were identified only in [35S]methionine labeling of SCC and not in non-SCC or human fibroblasts. Two lines of adeno-, one of squamous, and one of undifferentiated large-cell lung carcinoma exhibited similar surface protein patterns to one another. Nine distinguishing proteins (40 to 100 kDal) and at least five large proteins (greater than 100 kDal) were unique to these lines. The surface protein phenotypes for SCC and non-SCC were distinct from those for human lymphoblastoid cells and fibroblasts. However, the neuroendocrine features of SCC were further substantiated because 6 of the 12 distinguishing SCC surface proteins, including E and U, were identified on human neuroblastoma cells. The proteins identified should (i) help define differentiation steps for normal and neoplastic bronchial epithelial cells, (ii) prove useful in better classifying lung cancers, and (iii) be instrumental in tracing formation of neuroendocrine cells.

Intracellular keratins in normal and pathological bronchial mucosa. Immunocytochemical studies on biopsies and cell suspensions.

The distribution of intracellular keratins was investigated in normal bronchial epithelium and in several morphologically distinct forms of respiratory tract carcinomas. This study was performed with two different experimentally produced antisera against normal human stratum corneum keratin and against keratin protein of MW 67,000 dalton, using indirect immunofluorescence and immunoperoxidase methods on tissue sections and cell suspensions. In normal bronchial epithelium, the basal cells were strongly labelled by both antisera. The ciliated columnar cells appeared devoid of cytokeratins in tissue sections but were strongly labelled with both antisera in cell suspensions. The goblet cells remained negative in every case. In squamous metaplasia of the bronchus, all epithelial cells were unevenly stained with both antisera. Among tumours, only the squamous cell carcinomas were strongly labelled by both antisera. Primary lung adenocarcinoma appeared weakly positive, whereas metastatic lung carcinomas, undifferentiated lung carcinomas, oat cell tumours, carcinoid tumours were negative. The immunocytochemical determination of keratins appeared to be of value in the study of normal and abnormal epithelial differentiation, in the diagnosis of poorly differentiated carcinomas and in their distinction from metastatic tumours of the lung.

Unpredictable course of small cell undifferentiated lung carcinoma

Twenty-nine patients with small cell lung carcinoma were examined as to ultrastructural morphology, stage of disease, and survival. Although all tumors met the light microscopic criteria for oat cell carcinoma, only 19 (66%) contained neurosecretory granules characteristic of this tumor. Of 12 patients undergoing pulmonary resection, five of six patients with non-neurosecretory tumors and two of six patients with neurosecretory (true oat cell) tumors survived more than 2 years. Survival of all patients with Stage I or II disease was significantly different from that of patients with Stage III disease. Stage together with ultrastructural morphology may carry important therapeutic and prognostic implications. Pulmonary resection appears to be effective treatment for certain subsets of patients with small cell undifferentiated carcinoma.

The superiority of combination chemotherapy over single agent chemotherapy in small cell lung carcinoma

From June 1974 to October 1976, 288 patients with small cell undifferentiated lung carcinoma were entered into a randomized, controlled study comparing the two noncycle-active induction regimens of cyclophosphamide vs. the combination of cyclophosphamide, doxorubicin and imidazole carboximide (DTIC). Patients were stratified by extent of disease, previous radiotherapy and performance status. Responding patients and those who did not progress were then randomized to receive their initial regimen alone, or their initial regimen with added cycle-active therapy (vincristine, hydroxyurea and methotrexate). While only 4/34 (12%) evaluable patients treated with cyclophosphamide achieved a response (greater than 50% regression), a final total of 119/217 (57%) evaluable patients on the three drugs have responded (p = 0.005). The survival curve for all the combination-treated patients was significantly better than for those treated with cyclophosphamide alone (p = 0.012). There was no demonstrable statistical superiority in length of remission or survival for patients on the combination who received in addition cycle-active consolidation therapy. In the combination chemotherapy group, survival duration was longer for patients with limited disease than extensive disease (p = 0.035). There was a strong correlation between quality of remission produced by the combination and survival.