Alkylating agent resistance: in vitro studies with human cell lines.

Development of in vitro resistance to HN2 (also called mustargen or mechlorethamine hydrochloride), N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU), and cisplatin [cis-diamminedichloroplatinum(II)] was achieved in two human cell lines, the Raji/Burkitt lymphoma and a squamous cell carcinoma of the tongue. A 10- to 20-fold increase in resistance relative to the parental line was achieved in 3-4 months of continuous selection pressure. At this time, further increase in selection pressure resulted in cell death, while removal of drug led to rapid loss of resistance.

Detection of bone marrow metastasis in small-cell lung cancer by monoclonal antibody.

A murine monoclonal antibody against a surface antigen of small-cell carcinoma of the lung (SM1 antibody) was investigated for its use in detecting bone marrow metastasis. Bone marrow cells of healthy volunteers and of patients with small-cell carcinoma of the lung (SCCL) were examined for reactivity with SM1 antibody and indirect immunofluorescence and the results compared to conventional histochemical staining (Wright-Giemsa stain of bone marrow aspirates and hematoxylin-eosin stains of bone marrow biopsies). No SM1 reactivity was found in marrow cells of eight healthy volunteers.

Selective cytotoxicity of the SM1 monoclonal antibody towards small cell carcinoma of the lung.

A murine monoclonal antibody, SM1, is strongly reactive with the surface membrane of small cell carcinoma of the lung. SM1 antibody is unreactive with most other cancers and various normal tissues including bone marrow cells. We now find that SM1 antibody is selectively cytotoxic to small cell carcinoma (SCC) in vitro.

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.

Cytoskeleton-associated proteins: their role as cellular integrators in the neoplastic process.

The cytoskeleton (CSK) of eukaryotic cells is composed of a complex interconnected network of filaments which is important in a wide variety of cellular functions including changes in cell shape, cell motility, mitosis, anchorage-dependent growth, and the localization of cellular organelles such as mitochondria, polyribosomes, and secretory granules. The various proteins comprising the cytoskeleton include actin in microfilaments, tubulin in microtubules, and the heterogeneous group of intermediate filament proteins that are associated with different cell types (keratin in epithelial cells, vimentin in fibroblasts, desmin in muscle cells, glial filament protein in glial cells, and the neurofilament protein subunits in neural tissue). Many other proteins in glial cells, and the neurofilament protein subunits in neural tissue).

Membrane antigen in small cell carcinoma of the lung defined by monoclonal antibody SM1.

Mouse myeloma cells were fused with spleen cells from BALB/c mice immunized with a cell line derived from human small cell carcinoma (SCC) of the lung. The cloned hybridoma SM1 produced antibody that was reactive with the surface membrane of SCC cell lines and SCC tumors but not with the membrane of several non-SCC cell lines and tumors. SM1 ascites fluid was used to screen for reactivity of the antibody with other human cancer cell lines, tumor tissues, and normal tissues.

Anticarcinoma activity in vivo of rhodamine 123, a mitochondrial-specific dye.

Carcinoma cells and normal epithelial cells differ in the mitochondrial retention of a permeant cationic compound, rhodamine 123. The possibility of utilizing this difference in carcinoma chemotherapy was investigated. Rhodamine 123 exhibited anticarcinoma activity in mice, and this activity was potentiated by 2-deoxyglucose.

In vitro and in vivo growth characteristics of two different cell populations in an established line of human neuroblastoma.

Two distinct cell morphologies were appreciated and separated in a long-established culture line (CHP-100) of human neuroblastoma. Both cell types carried chromosomal markers characteristic of neuroblastoma cells and the parent line; in addition, separate karyotypic changes in each cell type established them as separate and enriched populations. A small, refractile cell, designated CHP-100-S, was present and formed numerous cytoplasmic processes.

Selective toxicity of rhodamine 123 in carcinoma cells in vitro.

The study of mitochondria in situ has recently been facilitated through the use of rhodamine 123, a mitochondrial-specific fluorescent dye. It has been found to be nontoxic when applied for short periods to a variety of cell types and has thus become an invaluable tool for examining mitochondrial morphology and function in the intact living cell. In this report, however, we demonstrate that with continuous exposure, rhodamine 123 selectively kills carcinoma as compared to normal epithelial cells grown in vitro.

Effects of dibutyryl cyclic adenosine 3':5'-monophosphate on the growth of cultured human small-cell lung carcinoma and the specific cellular activity of L-dopa decarboxylase.

High activity of L-dopa decarboxylase separates small (oat)-cell from non-small-cell lung cancer in cell culture. The present study investigates relationships between the specific cellular activity of this enzyme and: (a) cell growth kinetics of an established line (O-H-1) of human small cell lung carcinoma, and (b) responses of these cells to treatment with cyclic adenosine 3':5'-monophosphate and sodium butyrate. The O-H-1 cells, as for most other established small-cell lines, grow as suspended cell aggregates.

Rhodamine-123 selectively reduces clonal growth of carcinoma cells in vitro.

Rhodamine-123, a cationic laser dye, markedly reduced the clonal growth of carcinoma cells but had little effect on nontumorigenic epithelial cells in vitro. This selective inhibitory effect of Rhodamine-123 on some carcinomas is unusual since known anticancer drugs, such as arabinosyl cytosine and methotrexate, have not been shown to exhibit such selectivity in vitro.

Induction of cytoskeleton-associated proteins during differentiation of human myeloid leukemic cell lines.

Alterations in the expression of proteins associated with the cytoskeletal framework during differentiation of two human myeloid leukemia cell lines were analyzed by two-dimensional gel electrophoresis of Triton-insoluble cellular framework fractions. During in vitro differentiation of HL60 (human promyelocytic leukemia line) and U937 (human monocytoid leukemia line), several new cytoskeleton-associated (CSK) proteins are induced. All of these CSK proteins are also present in freshly isolated normal granulocytes and macrophages.

Unusual retention of rhodamine 123 by mitochondria in muscle and carcinoma cells.

Mitochondria in cardiac muscle cells and myoblast-fused myotubes display unusually long (3-5 days) retention times of rhodamine 123, a mitochondria-specific fluorescent probe, in living cells. Among 50 keratin-positive carcinoma or transformed epithelial cell lines tested, mitochondria with prolonged rhodamine 123 retention are detected in most of the transitional cell carcinoma, adenocarcinoma, and chemical carcinogen-transformed epithelial cell lines and in some squamous cell carcinoma lines but not in any oat cell carcinoma lines. The presence of mitochondria having unusual dye retention may be useful for diagnosis and exploitable for chemotherapy of certain human carcinomas.

Monitoring the effect of anti-cancer drugs on L1210 cells by a mitochondrial probe, rhodamine-123.

The cancer chemotherapeutic agents 1-beta-D-arabinofuranosylcytosine (Ara-C), methotrexate, and 5-fluorouracil cause a rapid loss of mitochondrial Rh-123 uptake in L1210 cells, which correlates with the loss of clonogenic ability. The loss of Rh-123 uptake is irreversible and occurs prior to Trypan Blue staining. Thus, the antimetabolites, unlike freeze-thawing and detergent treatments, generally cause mitochondrial damage prior to changes in plasma membrane permeability.

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.

Requirement of initiation factor 3 in the initiation of polypeptide synthesis with N-acetylphenylalanyl-tRNA.

Initiation factor 3 is required, along with initiation factors 1 and 2, for the incorporation of N-acetylphenylalanine into polypeptides and the formation of N-acetylphenylalanylpuromycin. Initiation factor 3 also strongly stimulates the binding of N-acetylphenylalanyl transfer RNA to isolated 30S ribosomal subunits. Phosphocellulose fractions of initiation factor 3 were found to catalyze N-acetylphenylalanine incorporation differentially with different synthetic messenger RNAs not containing any codons for N-formylmethionine.