Culture of human brain tumors on an extracellular matrix derived from bovine corneal endothelial cells and cultured human glioma cells

Cell culture has become an integral part of the daily routine of most oncology laboratories. It has enabled researchers to investigate a wide range of cellular parameters in a defined system in which the experimental conditions can be controlled and repeated. Although the manufacturers of tissue culture materials are continually improving their products, cell attachment and initial survival of primary cultures from tumor cells are still problems in many laboratories. Many different approaches have been taken to circumvent this problem, and coating of tissue culture dishes with attachment enhancers, such as polyamino acids (1), fibronectin (2), laminin (3), and collagen (4), has been found helpful. For a long time, it was known that endothelial cells produce a basement membrane, and this led to the use of bovine corneal basement membrane by Gospodarowicz et al. (5,6), in their research into the phenomenon of regeneration and nonregeneration of corneal endothelium in different species. The application of this bovine corneal extracellular matrix (bECM) has since been greatly expanded (5,6). bECM has found broad approval, and has been used for mammary carcinoma (7), urological tumors (8), and different kinds of pituitary adenomas (9,10) as well as CNS tumors (11).

Growth factor biology and oncogene activation in human gliomas and their implications for specific therapeutic concepts

The failure of most available treatment modalities to improve the survival time and the quality of survival in patients with gliomas calls for the intense biological analysis of glial neoplasia. The untimely activation of cellular protooncogenes is often related to the process of neoplasia. Several protein growth factors as well as their cellular receptors have been identified as products of proto-oncogenes. Furthermore, these growth factors have been identified as glial mitogens in normal glial cell cultures as well as in tumors. The analysis of growth factor biology gains additional weight by the demonstration of autocrine growth factor secretion by tumor cells. The role of epidermal growth factor (EGF) and its receptor system in glial cell proliferation and differentiation is presented, with the speculation that the EGF receptor system may integrate the biological actions of many different factors, of which EGF itself may be least important. The literature on platelet-derived growth factor and insulin-like growth factors is reviewed, and the biology of fibroblast growth factor is presented in perspective with such phenomena as neovascularization and cell-matrix interactions.

Pre-operative localized in vivo proton spectroscopy in cerebral tumors at 4.0 Tesla--first results

Sixteen patients with prediagnosed cerebral lesions were studied with stimulated echo localized 1H-spectroscopy at 4 Tesla. Initially, CT cerebral angiography and MR investigation at 1.5 Tesla were performed. After selecting a patient and receiving his agreement the high field examination started with the acquisition of an MR image of the known tumor at 4 Tesla using head or surface coil. 1H-spectroscopy was performed by selectively exciting a cubic volume between 8 to 20 cubic centimeters in the center of the tumor, in one case below 4 ccm (pinealoma). If possible, in a second examination the corresponding opposite side of the brain was studied. The extirpation of the tumor followed during the next days. Macroscopic aspects, histology and grading of the investigated lesions were determined. In some cases, specimens of the tumors were cooled in cooking salt solution and in liquid nitrogen, respectively, in order to perform in vitro proton MRS at 8.4 Tesla. The evaluable in vivo spectra showed good resolution and significant differences between corresponding cerebral areas with and without tumor as well as between different types of tumor histologies like medulloblastoma, astrocytoma and meningeomas. Often a good correspondence between in vivo and in vitro spectroscopy was seen. No clinically relevant side effects or complications were observed during the in vivo high field examination.

Cyst fluids of malignant human brain tumors contain substances that stimulate the growth of cultured human gliomas of various histological type

The contents of 14 cysts that were located within human intracranial tumors were obtained at surgery by needle aspiration. These tumor cyst fluids (TCFs) were mostly derived from glial tumors (10 cases). TCFs from one metastasis from a mammary carcinoma, one cystic meningioma, one hemangioblastoma, and a cystic acoustic neurinoma were also included. These TCFs were added to primary cultures of human gliomas, established human glioma cell lines, and normal human arachnoid cells in culture. The presence of proliferation-promoting factors in all cyst fluids could be demonstrated. On the basis of the response patterns of the cultures, it was possible to distinguish different levels of growth autonomy and growth factor sensitivity among these cultures and to speculate about varying degrees of cellular autocrine activation. The TCFs appear to contain factors that are not normally present in fetal calf serum, which is a regular constituent of most cell culture media. Some primary cultured cells as well as cell lines react in an oversensitive manner to the addition of TCFs.

Cyst Fluids of Malignant Human Brain Tumors Contain Substances That Stimulate the Growth of Cultured Human Gliomas of Various Histological Type

The contents of 14 cysts that were located within human intracranial tumors were obtained at surgery by needle aspiration. These tumor cyst fluids (TCFs) were mostly derived from glial tumors (10 cases). TCFs from one metastasis from a mammary carcinoma, one cystic meningioma, one hemangioblastoma, and a cystic acoustic neurinoma were also included. These TCFs were added to primary cultures of human gliomas, established human glioma cell lines, and normal human arachnoid cells in culture. The presence of proliferation-promoting factors in all cyst fluids could be demonstrated. On the basis of the response patterns of the cultures, it was possible to distinguish different levels of growth autonomy and growth factor sensitivity among these cultures and to speculate about varying degrees of cellular autocrine activation. The TCFs appear to contain factors that are not normally present in fetal calf serum, which is a regular constituent of most cell culture media. Some primary cultured cells as well as cell lines react in an oversensitive manner to the addition of TCFs.

A developmentally regulated gene product from Dictyostelium discoideum shows high homology to human alpha-L-fucosidase

A cDNA library of poly(A+)-RNA has been prepared from membrane-bound polysomes of Dictyostelium discoideum and screened for clones hybridizing to mRNA species that encode developmentally regulated proteins. The clone investigated in this paper recognizes a 1.8 kb transcript that accumulates strongly between the growth phase and aggregation stage. Stimulation of cells with pulses of cAMP enhances the accumulation. The amino acid sequence derived from a complete cDNA and from a genomic clone displays extensive sequence identity to human liver alpha-L-fucosidase. The D. discoideum DNA sequence encodes a 50.5 kDa polypeptide with a hydrophobic signal peptide at the N-terminus. Antibodies against a synthetic peptide corresponding to amino acids 262-275 of the deduced protein sequence recognize a developmentally regulated 50 kDa protein in D. discoideum that is recovered in the particulate fraction.

Spectrum of karyotypic aberrations in cultured human meningiomas

Twenty-two unselected cases of meningioma were initiated in tissue culture on an extracellular matrix derived from bovine corneal endothelial cells. The cultures were available for karyotypic analysis at passages 1 to 5, representing cultivation periods of up to two months. Histologically, the meningiomas were meningiotheliomatous (16 cases), fibrous (1 case), angiotheliomatous (1 case), microcystic (2 cases), and parenchymatous (2 cases). Two of the meningotheliomatous cases had histological signs of malignancy, another case showed increased signs of proliferation, and two cases were recurrences, one after a complete course of irradiation. In five cases no structural chromosome aberrations were found. Monosomy of chromosome 22 was found in six cases and was associated with other random aberrations. Clonal or random aberrations without monosomy 22 were present in 11 cases, including one case with trisomy 7 and another case with a stable translocation marker, t(4;7). In these latter two cases, EGF-receptor binding was not elevated, compared to other meningiomas. Our results illustrate that, in addition to the frequent involvement of chromosome 22, numerous other individual clonal karyotype aberrations exist in meningioma cell populations, reflecting the heterogeneity of biological and pathological findings.

[Percutaneously implantable balloon-inflatable vascular prostheses. Initial clinical results]

Restenosis and occlusion of atherosclerotic arteries are prevented by a newly developed arterial prosthesis consisting of a pliable and elastic wire mesh tube positioned to the balloon of an angioplasty catheter. As the balloon is inflated the prosthesis dilates and provides the arterial wall with a new mechanical support. This new device was successfully implanted in ten patients having an iliac artery stenosis and improved the therapeutic result of the preceding angioplasty. There were no complications.

Complete cDNA sequence of a Dictyostelium ubiquitin with a carboxy-terminal tail and identification of the protein using an anti-peptide antibody

The complete sequence of a Dictyostelium discoideum cDNA is presented that codes for monoubiquitin extended at its C-terminus by a 52 amino acid tail. The sequence of both the ubiquitin portion and the tail is highly homologous to the one of Saccharomyces cerevisiae and to a partial mouse sequence. The highly basic tail sequence contains a putative metal and nucleic acid-binding motif. The gene encoding the 0.6 kb mRNA of the C-terminally extended ubiquitin is represented only once in the haploid genome. The 0.6 kb mRNA as well as its translation product, a 15 kDa protein, is expressed in exponentially growing cells and remains present for at least 5 h of development. Using antibodies against a synthetic peptide that corresponds to the C-terminal amino acid sequence, a 15 kDa protein containing the extension a synthetic peptide that corresponds to the C-terminal amino acid sequence, a 15 kDa protein containing the extension was also detected in yeast.

[The biology of gliomas: growth factors and oncogene expression. A current review]

In recent years several proteins with in vitro cell growth promoting activity were chemically identified and termed growth factors. Their role in normal glial development has been studied in vitro in different defined systems. In addition it has been tried to elucidate their role in the biology of gliomas. Some clues were obtained from the study of growth factor receptors and the expression of oncogenes. It has to be assumed that from the correlation and synthesis of results obtained from studies of growth factors, oncogene expression, gliogenesis and cytogenetics there will emerge useful biological concepts for specific therapeutic approaches.

Biological and karyotypic characterization of a new cell line derived from human gliosarcoma

A cell line (NCE-G28) was established from the biopsy material of a human gliosarcoma of low histological differentiation. The initial cultures showed a mixed population of cells which in later stages became more uniform due to loss of slower growing constituents. The cells have been growing steadily for 20 months. A suspension of NCE-G28 cells injected s.c. as well as i.p. into nude mice produced solid tumors in all cases. Histologically these tumors closely resembled the original tumor. The original tumor, the nude mouse tumor, and NCE-G28 cells were immunochemically positive for glial fibrillary acidic protein as well as for neural plasma membrane antigen A2B5 expression. Two cell strains, 9B2C and 9B2E, were obtained by cloning of the initial cultures and another strain, NCE-G28T, was derived after explantation of a mouse heterotransplant. The two subclones were negative for glial fibrillary acidic protein expression but stained for cell surface fibronectin. NCE-G28T cells initially were positive for glial fibrillary acidic protein but lost this property within 8 months of cultivation. Karyotype analysis of NCE-G28 and the three strains revealed hyperdiploidy and six structurally altered marker chromosomes five of which were shared by nearly all cells. Receptors for epidermal growth factor were detected in all cell lines with the highest levels (about 300,000 receptors/cell) in the parental cell line. The epidermal growth factor receptors had an affinity of 2.5 nM (Kd) and by affinity cross-linking analysis a molecular weight of 170,000 was found. Initially, NCE-G28 cells responded to epidermal growth factor as well as fibroblast growth factor with increased rates of proliferation, while platelet derived growth factor had no effect. In higher passages the growth factor sensitivity was reduced. Using antibodies directed against synthetic protooncogene peptides the production of c-sis immunoreactive material was detected. NCE-G28 cells produce an autocrine factor which stimulated proliferation. This factor is present in conditioned medium and is active on cultured meningiomas and other glioma cell lines. NCE-G28 cells can be maintained in serum-free defined medium on plastic coated with fibronectin or an extracellular matrix from bovine corneal endothelial cells. The NCE-G28 cell line with its strains provide an in vitro model system in which the complexity of gliosarcoma cell populations and the interaction of the cloned cellular constituents can be studied.

Growth factors in cultured human glioma cells: differential effects of FGF, EGF and PDGF

Primary cell cultures were initiated from surgically obtained specimens from human gliomas. After 4-10 passages in vitro the cells from 18 individual cases were seeded onto cluster dishes and left to attach for 24 h in medium containing fetal calf serum. Thereafter the medium was changed to serumfree, defined conditions and the following growth factors were added: EGF 1.5 x 10-8 M, PDGF 35 ng/ml, FGF 80 pg/ml. The growth factors were added fresh every 2 days. After 9 or 11 days in culture, the cells on one multiwell-plate were counted. In 8 cases another set which was cultured also in a multiwell-plate but on glass cover slides was immunostained for glial fibrillary acidic protein (GFAP), fibronectin (FN), A2B5 and galactocerebroside (galC). The proliferative response pattern in consequence to the growth factor addition varied greatly between different cases. In all cases a pronounced proliferative response was accompanied by marked changes on the culture morphology. Usually the best proliferative response was obtained with PDGF (10 cases) or FGF (8 cases) whereas EGF was most effective only in one case. Two cases showed only minimal response, one of which was an oligodendroglioma D according to Ludwig and another a gliosarcoma which was re-evaluated after 1 year in culture. It could be noted, however, that FGF had a tendency to be less effective in the group of malignant astrocytomas. The staining pattern of the cultures with the afore mentioned markers was not affected by the growth factor treatment. The proliferative response usually resulted in increased staining for fibronectin and never an induction of GFAP. A2B5 staining was positive only in one case of gliosarcoma and galC staining was regularly negative.

Cushing's syndrome due to bilateral adrenal macronodular hyperplasia with undetectable ACTH: cell culture of adenoma cells on extracellular matrix

A 59-year-old man developed Cushing's syndrome with massive bilateral adrenal macronodular hyperplasia. Plasma ACTH levels were undetectable both peripherally and in the inferior petrosal sinus. Computed tomography scans of his pituitary were normal. Hypercortisolism was not suppressed by high doses of dexamethasone. His adrenal cells were successfully isolated and grown on bovine corneal extracellular matrix. The cultured cells displayed strikingly rapid growth and hypersecretion of cortisol during incubation with control serum. Addition of the patient's serum to cultured fetal adrenal cells did not accelerate their growth. This was the first experience with our in vitro system in this rare clinical condition. The techniques described here may be used for future in vitro adrenal studies. These in vivo and in vitro data indicate that this patient's bilateral adrenal hyperfunction and growth were independent of ACTH.

Glioma biology in vitro: goals and concepts

Gliomas are heterogeneous in their cellular composition, affecting therapeutic efforts such as surgical removal, radiotherapy, chemotherapy and immunotherapy. 106 gliomas were taken into culture in our laboratory and 12 cell lines could be established there from. Experiments were carried out in as many early cultures as possible and with the constant experimental system of the cell lines. To subdivide and possibly classify the heterogeneous group of gliomas the following approaches emerged: Immunostaining of cells for glial markers such as GFAP, A4, A2B5, Leu 7 as well as fibronectin will allow one to distinguish different groups of glial cultures. Performance of growth factor sensitivity tests allows the assessment of major aspects of growth control in cultured gliomas. Cytogenetic evaluation in early cultures and correlation with the expression of oncogenes may yield useful information on mechanisms of escape from normal growth control. One of our cell lines (NCE-G28) in which cells switch from GFAP to fibronectin expression and transiently express the x-hapten may serve as a model to study crucial aspects of cellular differentiation. Using different extracellular matrices for the initiation of cultures even from very benign lesions with low proliferative potential it is possible to include these into comparative studies with glioblastomas.

Clinical and laboratory findings in patients with multiple meningiomas

A series of eight patients with multiple meningiomas is presented. Up to 14 meningiomas were diagnosed in one patient. The clinical and laboratory findings suggest that multiple meningiomas do not constitute a disease entity of their own featuring disease-specific clinical or laboratory findings. In our series we find a female predominance with seven female and one male patient. The histological findings were mixed, even within the individual cases. There are no consistent patterns of steroid receptor levels or chromosomal aberrations in the more recent cases in which these parameters could be investigated.

Initiation of primary cell cultures from human intracranial tumors on extracellular matrix from bovine corneal endothelial cells

Tissue specimens from 105 human gliomas and 57 human meningiomas were obtained at surgery, dissociated into single cells and small cell aggregates and then plated onto plain plastic tissue culture dishes and dishes which had been precoated with an extracellular matrix (ECM) derived from bovine corneal endothelium. In 80% of the glioma cases we observed a marked improvement in initial plating efficiency, colony formation and speed of attachment when cells were plated on ECM. In 5 cases cells attached only to the ECM-coated dishes but remained afloat in the untreated dishes. In addition it could be noted that over the first 2 days, those cells which had been initiated on ECM showed more signs of morphological differentiation, i.e., extension of cytoplasmic processes or formation of fiber networks between cell groups. If adaptation occurred and proliferation began in vitro, either immediately or after a several days' lag phase, both the ECM-cultured cells as well as those which slowly had adapted to culture on plastic could be passed on to untreated culture ware and perpetuated thereon. In the case of well-differentiated low-grade gliomas where no growth in culture took place, the cultures on ECM could at least be used for initial experiments in the primary cultures (P0). Meningiomas usually attached well to both, plastic or ECM. In 50% of our cases the plating efficiency was higher on ECM but after successful initial culture, the delay until the cells on plastic reached confluence in comparison with those on ECM was 1 or 2 days. Again there were 2 cases in which the cells would not plate on plastic. Here the cells which after 1 day were still afloat plated to more than 80% within the first 2 h after transfer to ECM. In all cases the cells from plastic and ECM cultures were indistinguishable and could be passed onto untreated dishes henceforth. In later culture stages ECM offers several advantages: It is easier to shift cells to serum-free defined culture conditions, the cells will grow at a faster rate on ECM when in higher passages and the maximal number of passages possible is higher on ECM.

Complete sequence and transcript regulation of a cell adhesion protein from aggregating Dictyostelium cells

Three cDNA clones coding for the contact site A (csA) protein, a cell adhesion molecule of Dictyostelium discoideum, were isolated by screening a cDNA library with monoclonal antibodies. Two of these clones contained the complete coding region for the csA protein of 1542 bp including a sequence of 57 bp coding for the leader. The N terminus of the mature protein, as it was published previously, was identified in the amino acid sequence derived from both full-length cDNA clones. Southern blot analysis suggests the presence of only one csA gene in the haploid genome. Accumulation of the csA-specific message of 1.9 kb begins during development on nitrocellulose filters at 9 h of starvation, and reaches a maximum at 12 h, the time of cell aggregation. Expression of the csA glycoprotein follows closely accumulation of the transcripts. In the multicellular slug stage following cell aggregation, the amount of csA transcripts rapidly declines to low levels.

Prostaglandins: antiproliferative effect of PGD 2 on cultured human glioma cells

Five cultured human glioma cell lines were investigated for their reaction to prostaglandin (PG) D2 and E2. In all cases a suppressive effect on DNA synthesis as assessed by 3H-thymidine incorporation was seen with all test substances as early as six hours after the addition of the compounds in doses of usually 10(-5) M. A dose response curve was generated in four cases and showed an estimated ED 50 of about 5 X 10(-6)M. The effect was most pronounced at 12 hours after which the cultures began to recover except those which had been incubated with PGD2. In those cultures which had been exposed to PGD2 virtually no thymidine incorporation was seen after 24 hours and as long as 72 hours. In another set of experiments, the effect of PGD 2, PGE 2, two synthetic PGD 2 analogues, with a chlorine substitution in position 9 (DACl) or with a fluoride substitution in position 9 (DAF) and a synthetic prostacyclin-analogue (Iloprost) was investigated after single and repeated addition of the compounds. A second administration after 12 hours of incubation did not result in a further decrease in 3H-thymidine incorporation like that observed during that first incubation period. In general the cells recovered after 24 hours total incubation time except those which had received PGD 2 or repeated doses of PGE 2. Only in those cells which had been treated with PGD 2, an almost complete blockade of 3H-thymidine incorporation was seen even after the single administration. Parallel evaluation of the cells by flow cytometry showed effects on cell cycle distribution at different times of the incubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidermal growth factor--receptors on cultured human meningioma cells

Equilibrium binding assays of EGF were performed on confluent cultures of 12 human meningiomas at early passage. In all meningiomas complete binding curves were obtained and the resulting ED 50 values ranged between 0.5 and 6.3 nM. In four cases (ED 50 values ranging from 1.5 nM to 3.0 nM) where saturation analysis was performed, the sites were saturable at similar levels (7 nM). In five cases additional experiments were undertaken to evaluate the biological response of cultured cells to EGF as assessed by 3H-thymidine incorporation. In all cases EGF was a potent stimulus and increased 3H-thymidine incorporation by 2.5 to 6-fold. Functionally intact EGF receptors appear to be a regular feature of meningiomas in cell culture and appear not to be related to histological classification.

Long-term culture of human corticotropin-secreting adenomas on extracellular matrix and evaluation of serum-free conditions. Morphological aspects

Tissues from 12 human corticotropin-secreting adenomas, obtained during transsphenoidal surgery for Cushing's disease (CD, ten cases) or Nelson's syndrome (NS, two cases), were mechanically dispersed. The resulting single cells and cell aggregates were plated on extracellular matrix derived from bovine corneal endothelia. CD and NS cells showed distinct morphological differences initially, CD cells being much more spherical than the flattened NS cells. By 10 days at the latest after plating, however, CD and NS cells were indistinguishable morphologically. Cultured cells from both entities responded with rounding to cortisol (hydrocortisone, 10(-6) M) within 4-6 h. Synthetic ovine corticotropin-releasing factor (10(-8) M) produced flattening and extension of cytoplasmic processes after as early as 2 h.

Long-term culture of human corticotropin-secreting adenomas on extracellular matrix and evaluation of serum-free conditions. Secretory aspects

Tissues from 12 human corticotropin-secreting adenomas, obtained during surgery for Cushing's disease (CD, ten cases) or Nelson's Syndrome (NS, two cases), were exclusively mechanically dispersed. Single cells and cell aggregates were plated on extracellular matrix derived from bovine corneal endothelia. Functional responses to physiological stimuli were analyzed by measuring human beta-endorphin (beta h-EP) immunoreactivity (IR) by radioimmunoassay in the culture medium. All adenomas responded with stimulated secretory activity to arginine vasopressin (AVP), corticotropin-releasing factor (CRF), or both. Cortisol higher than 10(-8) M suppressed basal secretion and CRF- or AVP-stimulated beta h-EP-IR secretion. There was no consistent difference in response of the cells when cultured in medium containing 10% fetal calf serum (FCS) or in serum-free conditions. A change of cells from serum to serum-free conditions usually resulted in 10%-50% reduction in the basal secretion level that remained stable for at least 2 weeks and, in one case (NS), 10 weeks. In cells maintained in medium supplemented with 5% serum obtained from the respective patients 40 min after adenoma removal, basal secretion was suppressed to 60% of the baseline level in a 10% FCS control. Long-term incubation with CRF (10(-9) M) showed sustained stimulation of hormone secretion. No remarkable cell proliferation was observed under basal conditions or during long-term, low-dose incubation with cholera toxin (10(-12) M) in two cases (CD), or CRF (10(-9) M) in two cases (NS, CD). Parallel beta-EP-IR and adrenocorticotropin secretion was verified in selected cases.

Probing an adhesion mutant of Dictyostelium discoideum with cDNA clones and monoclonal antibodies indicates a specific defect in the contact site A glycoprotein

Expression of developmentally regulated membrane proteins of aggregating cells of Dictyostelium discoideum is subject to several control mechanisms. One of them involves periodic cyclic-AMP pulses as signals for gene expression. To increase the probability of selecting mutants specifically defective in the contact site A (csA) glycoprotein, one of the characteristic proteins of aggregating cells, we have bypassed the requirement for both cyclic-AMP pulses and another control element by two runs of mutagenesis. A ;double bypass' mutant, HG592, was obtained which aggregated in nutrient medium where wild-type did not develop. Mutants defective in expression of the csA-glycoprotein were selected from HG592 by fluorescence-activated cell sorting and colony immunoblotting using a monoclonal antibody specific for that protein. One among 51 csA-negative mutants, HG693, specifically lacked the capability of forming EDTA-stable intercellular contacts. It acquired chemotactic responsiveness and developed into fruiting bodies. Expression of the transcripts for eight developmentally regulated proteins was determined in HG693. Seven of the RNA species were normally expressed; they were recognized by cDNA clones which had been produced from poly(A) RNA isolated from membrane-bound polysomes. The single RNA species which was not substantially expressed in HG693 was recognized by a cDNA clone that was obtained by screening a lambdagt11 library with an antibody specific for the csA-glycoprotein. When probing RNA from wild-type cells, this clone hybridized with a single developmentally regulated RNA species of 1.9 kb whose expression was strongly enhanced by cyclic-AMP pulses. Appearance of this RNA coincided with the expression of the csA-glycoprotein.

Radioimmunoassay for an inhibin-like peptide from human seminal plasma

Antisera raised in rabbits to a synthetic peptide consisting of 31 amino acids with a sequence identical to inhibin-like peptide (ILP) isolated from human seminal plasma afford a highly specific and sensitive radioimmunoassay. Synthetic ILP completely displaces antiserum binding of radioiodinated [Tyr4]-ILP, with half maximal displacement at 36 fmoles ILP/tube. ILP, [Tyr4]-ILP and ILP-(9-31) had essentially equal potency, while ILP-(1-25), ILP-(1-23) and ILP-(1-16) had reduced potency. No cross reactivity was found among a variety of peptide hormones and proteins. Human seminal plasma displaces 50% of [125I-Tyr4]-ILP at dilutions equivalent to 50-250 pl/tube, corresponding to immunoreactive ILP concentration of 0.5-2.5 mg/ml.

Human retinoblastomas have binding sites for the COOH-terminal segment of human beta-endorphin

Two human retinoblastoma cell lines (Y79 and McA) were evaluated for the presence of binding sites for human beta-endorphin (beta h-EP). Using tritiated beta h-EP (3H-beta h-EP) and synthetic beta-EP analogues, it was possible to demonstrate binding sites for 3H-beta h-EP with an ED50 of 3.5 nM in Y79 cells and 8 nM in McA cells respectively. The non-opioid segment [beta h-EP-(6-31)] retained about 20% relative potency in Y79 and 40% in McA in displacing the tritiated hormone when compared with beta h-EP. Camel beta-EP had a relative potency of less than 1% and beta h-EP-(1-27) was inactive in both cells in doses as high as 4 microM. Taken together with previous reports on similar binding sites in human neuroblastoma and glioblastoma cell lines, it appears that cell lines of neural origin have binding sites for the COOH-terminal of human beta-EP.

Epidermal growth factor receptors in the human glioblastoma cell line SF268 differ from those in epidermoid carcinoma cell line A431

Two established human tumor cell lines, epidermoid carcinoma line A431 and glioblastoma line SF268, were studied to compare the interaction of each with epidermal growth factor (EGF). SF268 cells bound [125I] EGF with 35-40 fold higher affinity than did the A431 cells. The EGF binding sites of both lines were photoaffinity labeled using 2,4-NAPS-[125I] EGF, a photoreactive derivative of EGF. Extracts of photolysed cells analyzed by SDS-PAGE showed a difference between the two cell lines in the high molecular weight component corresponding to the EGF receptor. EGF in a dose range from 0.3-200 nM had no effect on thymidine incorporation by SF268 cells, whereas thymidine incorporation by A431 cells was markedly inhibited by EGF.

Beta-endorphin: photoaffinity labelling of a non-opioid binding site in a human neuroblastoma

A photoaffinity reagent 2-nitro-4-azidophenylsulfenyl chloride (2,4-NAPS-Cl) and synthetic analogs of human beta-endorphin (beta h-EP) were employed to demonstrate the presence of receptor sites specific for beta h-EP but of non-opioid character in a human neuroblastoma cell line (IMR-32). The radioactive photoaffinity probe was carried out using [125I-Tyr1,2,4-NAPS-Trp27]-beta h-EP and IMR-32 cell membranes. After solubilization with sodium dodecyl sulfate (SDS) and SDS polyacrylamide gel electrophoresis, a single labelled protein band was identified with a molecular weight of 72,000. Labelling was blocked by beta h-EP or beta h-EP-(6-31) but remained in the presence of beta h-EP-(1-27). The specificity of this band is thus identical to that of the non-opioid site previously characterized. Various nonionic or zwitterionic detergents did not extract the labelled non-opioid site.

Beta-endorphin does not protect alkylation of opiate receptor by N-ethylmaleimide

Rat brain membranes were incubated in N-ethylmaleimide (NEM, 0.5-1.0 mM) in the presence and absence of various concentrations of morphine, Leuenkephalin and human beta-endorphin (beta h-EP). After sufficient washing, the binding of dihydromorphine (DHM), [D-Ala-D-Leu]-enkephalin (DADLE) and tritiated beta h-EP was 10-40% above that of membranes treated with NEM alone. There was no additive effect of morphine and Leu-enkephalin with respect to their effect on recovery of beta h-EP binding. Evaluation of beta h-EP as protecting ligand proved to be difficult since preincubation completely inhibits subsequent DHM and DADLE binding unless a more extensive washing protocol is employed. A protocol for washing beta h-EP preincubated membranes using a Tris-phosphate buffer of pH 6 containing 150 mM NaCl, 20 mM MgCl2 and 10% glycerol was used to recover enough binding potential to evaluate the effects of beta h-EP preincubation towards NEM treatment. Preincubation with beta h-EP itself at 0.1-1.0 microM did not result in any increased recovery of opiate binding, in contrast to the findings with the other two ligands.

Synthetic insulin-like growth factor II

Human insulin-like growth factor II with 67 amino acid residues and three disulfide bridges has been synthesized by the solid-phase method. Homogeneity of the synthetic product is ascertained by chromatofocusing, high performance liquid chromatography and amino acid analysis. In both radioimmunoassay and radioreceptor assay, the synthetic product is indistinguishable from the natural hormone.

Characterization of immunoreactive beta-endorphin secreted from cultured human corticotropin-secreting adenomas

Seven human corticotropin-secreting adenomas causing Cushing's disease or Nelson's syndrome were maintained in long-term culture. Pooled media from the individual adenomas were analyzed for the composition of their secretory products. From a radioimmunoassay (RIA) with 100% cross-reactivity for human beta-endorphin (beta h-EP) and beta-lipotropin (beta h-LPH), immunoreactive beta h-EP (IR X beta h-EP) was found to be the predominant secretory product after Sephadex G-50 analysis in 4 cases (40-80% of total IR), immunoreactive beta h-LPH (IR X beta h-LPH) predominated in 1 case, and both were equipresent in 2-cases. IR X beta h-EP was further purified by high-performance liquid chromatography (HPLC) and analyzed in 4 cases with ion-exchange chromatography on SP-Sephadex C-25 and a RIA which completely cross-reacts with beta h-EP, [N alpha-Ac]-beta h-EP, beta h-EP-(1-27) and [N alpha-Ac]-beta h-EP-(1-27). In all cases, the IR X beta h-EP was the main component (40-70%); the remaining IR material was attributable partially to [N alpha-Ac]-beta h-EP or other, less defined immunoreactive material. In 3 cases, enough IR X beta h-EP material was available for HPLC and to perform a radioreceptor assay using tritiated beta h-EP as primary ligand. The displacing potency of these preparations relative to synthetic beta h-EP was related to the content of the immunoreactive component eluting in the position of synthetic beta h-EP.

Protease inhibition increases the analgesic potency of peptide E

Peptide E (PE), an opioid peptide from adrenal medulla, is known to possess very low analgesic potency when injected intracerebroventricularly in mice. The present study showed that PE analgesia was increased by co-injection with protease inhibitors (bacitracin and bestatin).

Binding characteristics of dermorphin, and [dermorphin1-7]-beta c-endorphin in rat brain membranes

Dermorphin and a camel beta-endorphin (beta c-EP) analog in which residues 1-7 correspond to the dermorphin sequence ([Dermorphin1-7]-beta c-EP) have been investigated with respect to their receptor binding characteristics using human and camel beta-EP as reference peptides. Tritiated dihydromorphine, [D-Ala2, D-Leu5]-enkephalin, ethylketocyclazocine and human beta-endorphin were used as primary ligands in the rat brain membrane preparation for radioreceptor assay. Camel beta-endorphin was the most potent peptide in all experiments. [Dermorphin1-7]-beta c-EP is significantly less potent towards 3H-ethylketocyclazocine and 3H-[D-Ala2, D-Leu5]-enkephalin but is as potent towards 3H-dihydromorphine and 3H-human beta-endorphin. Dermorphin itself weakly displaces tritiated dihydromorphine, [D-Ala2, D-Leu5]-enkephalin and ethylketocyclazocine (potency relative to camel beta-EP, 1-4%) but it is more potent (9%) in competition with tritiated human beta-endorphin. Dermorphin and the [Dermorphin-1-7]-beta c-EP appear to interact preferentially with mu opiate receptors.

Human beta-endorphin. Synthesis and biological activity of analogs with modifications in residue positions 3, 4 or 5

Three analogs of human beta-endorphin (beta h-EP) have been synthesized by the solid-phase method: [Phe2, Gly4]-beta h-EP(I), [Tyr5]-beta h-EP (II), and [Trp5[-beta h-ET (III). Analogs I and II are related to the highly potent hybrid analog [dermorphin1-7]-beta c-EP (beta c-EP). Radio-receptor-binding and analgesic assays gave relative potencies as follows, respectively: beta h-FP, 100, 100; I, 51, 43; II, 64, 30; III, 15, 4. The high potency of [dermorphin 1-7]-beta c-EP is not due to any one of the following structural elements: D-Ala2, Phe3-Gly4, Tyr5, and Pro6. Increasing hydrophobicity in position 5 (Met in beta-EP) leads to decreasing biological activity.

Human beta-endorphin. Synthesis and biological activity of analogs with modification in residue positions 8, 27, and 9 or 11

Three analogs of human beta-endorphin (beta h-ER) were synthesized by the solid-phase method: [Gln8,Trp27]-beta h-EP (I), [Gln8,Arg9,Trp27]-beta h-EP (II), and [Gln9,Arg11,Trp27]-beta h-EP (III). Radioreceptor binding assay with use of tritiated beta h-EP as primary ligand gave relative potencies as follows: beta h-EP, 100;I, 778;II, 467;III, 449. Relative potencies in an analgesic assay were: beta h-EP, 100;I, 114;II, 165;III, 83. The 8-11 segment of beta h-EP can tolerate a net increase in charge of +2 without diminishing analgesic potency. The substitution of Glu8 may be one of the more dependable means of designing beta-endorphin antagonists.

Synthesis of human pancreatic growth hormone-releasing factor and two omission analogs by segment-coupling method in aqueous solution

The human growth hormone-releasing factor (GRF) peptides [GlyS15]-GRF-(1-15) (IV), trifluoroacetyl-GRF-(20-44) (VI), trifluoroacetyl-GRF-(18-44) (VIII), and trifluoroacetyl-GRF-(16-44) (X) were synthesized by the solid-phase method. Each of the peptides was reacted with citraconic anhydride and the trifluoroacetyl group was removed by reaction with 10% hydrazine in water. The citraconylated GRF-(1-15) peptide was coupled to the (20-44), (18-44) or (16-44) peptides by reaction with silver nitrate/N-hydroxysuccinimide to give GRF-(1-15)-(20-44) (XII), GRF-(1-15)-(18-44) (XIII), or GRF-(1-44), respectively. GRF-(1-44) was shown to stimulate the release of rat growth hormone from rat pituitary cells with an ED50 = 8.8 X 10(-11)M. Peptides XII and XIII were inactive, either as agonists or as antagonists of the action of GRF-(1-44).

In vitro secretion of pro-opiomelanocortin (POMC) derived peptides in human ACTH-producing pituitary adenomas: evaluation of hormone ratios in different functional states

In 14 cases of ACTH-producing pituitary adenomas (8 cases of Cushing's disease and 6 cases of Nelson's syndrome) dispersed cells prepared from adenoma tissue were incubated in a superfusion or static incubation system and investigated for ACTH, beta-endorphin (beta-EP) and beta-lipoprotein (beta-LPH) production. Effects of cortisol and lysine vasopressin (LVP) were evaluated. During the superfusion a qualitatively parallel secretory pattern is obtained for all hormones. Quantitatively, however, the response to LVP stimulation is more pronounced for beta-endorphin-like immunoreactivity (beta-LPH/beta-EP-IR) causing ACTH/beta-LPH/beta-EP-IR ratios to change throughout single experiments. beta-EP/beta-LPH ratios, however, which were estimated by means of Sephadex G-50 gel chromatography at various key points of the superfusion, were constant for each tumor, although variable between different adenomas, ranging from 0.68 to 2.0. The results suggest neither a differential control for the secretion of the peptides investigated within individual tumors nor a direct effect of cortisol or LVP on pro-opiomelanocortin processing. Summarizing clinical data and in vitro findings such as secretory behavior or hormone ratios, we can find no characteristic differences between Nelson's syndrome and Cushing's disease.

beta-Endorphin: evidence for the existence of opioid and non-opioid binding components for the tritiated human hormone in NG108-15 cells

Human beta-endorphin (beta h-EP) binding on neuroblastoma X glioma hybrid NG108-15 cells using tritiated human beta endorphin (3H-beta h-EP) as a primary ligand was found to have a component which was not displacable with [D-Ser2 )-Leu-enkephalin-Thr6 (DSLET). The beta h-EP binding on these cells after saturation of the delta opiate sites with 200 nM DSLET was further characterized with synthetic beta h-EP analogs. The nonopioid binding site appears to recognize beta h-EP-(6-31), beta h-EP-(21-31) and beta h-EP-(28-31). Under these conditions, these COOH-terminal segments fully displace the tritiated beta h-EP. However, beta h-EP-(1-27) does not further displace 3H-beta h-EP in the presence of DSLET. The fact that a combination of DSLET and beta h-EP-(6-31) results in a full displacement of 3H-beta h-EP provides direct evidence for the existence of two binding sites for beta h-EP in NG108-15 cells, one recognizing the NH2-terminal enkephalin sequence and the other the non-opioid COOH-terminal segment.

Beta-endorphin: demonstration of binding sites in three human neuroblastoma cell lines specific for the COOH-terminal segment of the human hormone

This communication reports for the first time specific binding sites in human neuroblastoma cells for human beta-endorphin (beta h-EP). Three cell lines (IMR-32, NMB and Kelly) were investigated and found to bind tritiated beta h-EP with an apparent dissociation constant of 2.2-4.2 nM. Further characterization with camel beta-EP and synthetic analogs indicated that the binding is most likely mediated by the COOH-terminal segments. beta h-EP-(6-31) had significant potency (15-75%) and beta h-EP-(1-27) was without displacing activity. The camel beta-EP has below 1% of the human beta-EP activity.

beta-Endorphin: characterization of binding sites specific for the human hormone in human glioblastoma SF126 cells

The established human glioblastoma cell line SF126 was found to bind tritiated human beta-endorphin (beta h-EP) in a saturable fashion. From displacement studies, the ED50 was estimated to be about 2.5 nM. The Kd was estimated as 1.9 X 10(-9) M and Scatchard analysis showed a biphasic pattern with a predominant low-affinity component. Binding reached a maximum at about 90 min at 22 degrees C and was instantaneously reversible. Tritiated [D-Ala2,D-Leu5]enkephalin and tritiated dihydromorphine did not bind to the cells. Sodium at a concentration of 150 mM decreased the specific binding by 80%. The interaction with the cellular binding site appeared to be mediated by the COOH-terminal segment of beta h-EP, as beta h-EP-(6-31) retained a high potency for displacing tritiated beta h-EP, and beta h-EP-(1-27) has no activity. Camel beta-EP was only about 1% as active as the human hormone.

Detection of bovine pancreatic trypsin inhibitor (bPTI) in bovine and ovine pituitaries, bovine brain, and adrenal medulla. A specific radioimmunoassay for bPTI

An antiserum against bovine pancreatic trypsin inhibitor (bPTI) has been raised in rabbits. The antiserum does not cross-react with known pituitary hormones and other proteins. A specific radioimmunoassay for bPTI has been developed. The ED50 is about 250 fmol per assay tube and the sensitivity is reliable to 15 fmol per tube. Immunoreactivity could be detected in bovine and sheep pituitaries, bovine brain, and adrenal medulla, but not in human, pig, and rat pituitaries. In the bovine pituitary the immunoreactivity is restricted to the posterior lobe.

Monoclonal antibody against cytoplasmic lectins of Dictyostelium discoideum: cross-reactivity with a membrane glycoprotein, contact site A, and with E. coli beta-galactosidase and lac repressor

Monoclonal antibodies were raised against two soluble, galactose-binding lectins from cells of Dictyostelium discoideum, discoidin I and II. These antibodies reacted not only with both discoidins, but also with a plasma membrane glycoprotein of aggregation competent cells, called contact site A, and with two carbohydrate-binding proteins of E. coli, beta-galactosidase and lac repressor. The possibility that the antibody recognizes a structure common to different carbohydrate-binding proteins is discussed. The two carbohydrate-binding proteins of E. coli share with discoidin I the sequence -Ser-X-X-Ile-His(Pro)-Pro(His)-Leu-Thr- which might be responsible for the cross-reactivity.

[Dynamic cerebral computed tomography. A contribution to the nosology of cerebral space-occupying processes?]

Dynamic cerebral studies were carried out in 21 patients with cerebral abnormalities. Thirteen had tumours and eight showed vascular abnormalities. In most cases the diagnosis was confirmed by histology, but occasionally by angiography or by computed tomography and the clinical course. Dynamic cerebral studies were performed, involving the production of concentration-time curves following bolus injection of ordinary contrast medium. The type of contrast enhancement gave a better indication of the nature of the lesion. The method can be used together with the more common type of investigations, such as plain scans and contrast scans. The small number of patients requires further studies with larger numbers; for this a multi-centric study would be suitable.

Synthesis of adrenal peptide E and some of its biological activities

A synthesis of peptide E, a highly potent, 25-amino acid adrenal opioid peptide containing both a [Met]enkephalin at the NH2-terminus and [Leu]enkephalin sequence at the COOH-terminus, originally isolated from bovine adrenal medulla [D. L. Kilpatrick, T. Taniguchi, B. N. Jones, A. S. Stern, J. E. Shively, J. Hullihan, S. Kimura, S. Stein, and S. Udenfriend (1981) Proc. Natl. Acad. Sci. USA 78, 3265-3268], is reported. The synthesis was accomplished by the solid-phase method employing the 4-(aminoacyloxymethyl)phenylacetamidomethyl(Pam)-copoly(styrene-1% divinylbenzene) resin. Two synthetic strategies (N-indole formyl protected vs unprotected tryptophan) were followed and results compared and evaluated. It was determined that peptide E prepared with protection of tryptophan (residues 13 and 14) was preferred and gave final product that was readily purified by HPLC. The biological activity of the synthetic material was found to be equivalent to the reported activity of the natural compound.

Comparative studies on the structural organization of membrane-depleted nuclei and metaphase chromosomes

Interphase membrane-depleted nuclei and metaphase chromosomes were prepared in parallel with a nonionic detergent lysis procedure at low ionic strength. By flow microfluorometry we showed for the first time that cell lysates contain all stages of the cell cycle in the same proportions as the starting cell population. Morphologically intact membrane-depleted nuclei and metaphase chromosomes were isolated as non-aggregated structures on sucrose gradients. When analysed in the electron microscope, membrane-depleted nuclei that had been treated with 2M NaCl appeared as residual structures containing the pore complex-lamina layer attached to a halo of DNA filaments. In contrast, no distinct high salt-resistant structure was found with metaphase chromosomes. They formed a highly fragile network which disintegrated easily into small complexes connected with DNA filaments. High salt-resistant DNA-protein complexes were purified by Metrizamide density gradient centrifugation. The main difference in the protein composition of interphase and metaphase residual complexes was the presence in interphase of a protein triplet in the 60-75 kilodalton molecular weight range and its absence in metaphase. This protein triplet most likely corresponds to the lamins A, B, and C of the nuclear lamina. The combined results suggest that the main difference in the structural organization of interphase nuclei and metaphase chromosomes is the presence or absence of the pore complex-lamina layer.

Peptide E: opiate receptor binding profile in the rat brain membrane assay. Comparison with beta-endorphin

Beta-endorphin (beta-EP) and peptide E were compared in respect to their binding potency in the rat brain membrane by radioreceptor binding assay using tritiated human beta-EP, [D-Ala2,D-Leu5]-enkephalin (DADLE), dihydromorphine (DHM) and ethylketocyclazocine (EKC) as primary ligands. When the potency of beta h-EP was chosen to be 100%, peptide E was equipotent with beta-EP in displacing DHM (95%) and EKC (103%) less potent for competing with beta h-EP (60%) and least active (7%) for displacing DADLE. It may be concluded that peptide E binds preferentially with the opiate mu and kappa receptors in the rat brain membrane.