Amplification of the C-erbB-2(HER-2/neu) proto-oncogene in ovarian carcinomas

C-erbB-2(HER-2/neu) proto-oncogene is mainly expressed in epithelial tissue and activated due to its amplification. Amplification of the C-erbB-2 proto-oncogene has been associated with poor prognosis in human ovarian cancer. Our study was to examine whether amplification is more frequently observed in ovarian cancer, or it is associated with poor prognosis of human ovarian cancer in China. The DNA of ovarian cancers was extracted and consequently digested with restriction endonuclease EcoRI, electrophoresed in 0.8% agarose gels and blotted onto nitrocellulose filter with Southern transferring method. It was then hybridized with a 32P-labelled C-erbB-2 probe and subsequently underwent autoradiography. The result has shown that the C-erbB-2(HER-2/neu) gene was amplified in 8 of 26 human ovarian cancers (30.8%). The clinical data showed that all of the 8 cases with the amplified C-erbB-2 were in their advanced stage (III-IV). Five of the patients died from 2 to 4 months after operation. These data suggest that amplification of the C-erbB-2 gene may play a role in the pathogenesis of ovarian carcinoma; it is frequently observed in advanced ovarian cancer and is associated with poor prognosis for these patients.

Radioimmunodetection of prostatic cancer: in vivo use of antibody against r-seminoprotein for diagnosis of prostatic cancer

Forty patients (25 cases of prostatic cancer and 15 cases of benign prostatic hyperplasia) were examined with radioimmunodetection (RAID) using antibody against r-Seminoprotein (r-Sm). The images of malignant tumor sites were revealed from the scan of single photon emission computerized tomography with the tracing of dual radionuclide and computer digital subtraction technique. Of the 25 patients with prostatic cancer tested, twenty-four were demonstrated in RAID with a positive rate of 96%. The ratio of taking in nuclide radioactivity between the tumor tissue and normal tissue (T/N) was 6.9 and the best showing time was the 96th hr from injection of radioactive antibody against r-Sm. The minimum diameter of the tumor detected in RAID was 0.5 cm. All of the 8 cases of metastatic prostatic cancer in pelvic or bone location were detected, with a rate of 100%. Of the 15 cases of benign prostatic hyperplasia, only one showed mild positive result. B-ultrasonography and CT showed a positive detective rate of 72.7% and 65%, respectively. Our results have indicated that RAID using 131I-labeled antibody against r-Sm possesses more advantages in specificity, because RAID not only defines the involved sites, but also shows the sites of the original tumors, and the metastatic location as well as the relationship between them.

Labeling of cysteine 231 in acetylcholinesterase from Torpedo nobiliana by the active-site directed reagent, 1-bromo-2-[14C] pinacolone. Effects of 2,2'-dipyridyl disulfide and other sulfhydryl reagents

Acetylcholinesterase (AcChE, EC 3.1.1.7) was isolated from the electric organ of T. nobiliana and treated with the active-site-directed alkylating agent 1-bromo-2-[14C]pinacolone ([14C]BrPin), or with BrPin, which acts initially as a competitive inhibitor, Ki = 0.18 mM, and then inactivates the enzyme, k2 = 1.8 x 10(-4) s-1. AcChE aliquots were digested with trypsin and fractionated by reversed phase high performance liquid chromatography. Inactivation caused a decrease in one absorption peak and an increase in another, identified as the peptide beginning at Ala-222 and extending to Arg-242. 5-Trimethylammonio-2-pentanone, a competitive inhibitor, isosteric with acetylcholine, retarded the inactivation and decreased the quantity of labeled peptide. On sequencing, the 14C label was found associated with Cys-231. This was confirmed by comparison with synthesized S-pinacolonylcysteine, by study of effects of blocking the sequencing by o-phthalaldehyde, and by inactivation by 2,2'-dipyridyl disulfide (2-PDS), a thiol-specific reagent that acts initially as a competitive inhibitor, Ki = 0.042 mM, and then inactivates the enzyme, k2 = 5.0 x 10(-4) s-1. This is retarded by 5-trimethylammonio-2-pentanone, and prior inactivation by 2-PDS prevents subsequent reaction of [14C]BrPin in the active site. BrPin inactivates AcChEs from Electrophorus electricus and from human erythrocyte, but 2-PDS does not. Neither reagent inactivates butyrylcholinesterases from human and horse serum.

Structure of the noncompetitive antagonist-binding site of the Torpedo nicotinic acetylcholine receptor. [3H]meproadifen mustard reacts selectively with alpha-subunit Glu-262

[3H]Meproadifen mustard, an affinity label for the noncompetitive antagonist site of the nicotinic acetylcholine receptor (AChR), specifically alkylates the AChR alpha-subunit when the acetylcholine-binding sites are occupied by agonist (Dreyer, E. B., Hasan, F., Cohen, S. G., and Cohen, J. B. (1986) J. Biol. Chem. 261, 13727-13734). In this report, we identify the site of alkylation within the alpha-subunit as Glu-262. AChR-rich membranes from Torpedo californica electric organ were reacted with [3H]meproadifen mustard in the presence of carbamylcholine and in the absence or presence of nonradioactive meproadifen to define specific alkylation of the noncompetitive antagonist site. Alkylated alpha-subunits were isolated and subjected to chemical or enzymatic cleavage. When digests with CNBr in 70% trifluoroacetic acid or 70% formic acid were fractionated by gel filtration high performance liquid chromatography (HPLC), specifically labeled material was recovered in the void volume fractions. Based upon NH2-terminal sequence analysis, for both digests, the void volume fractions contained a fragment beginning at Gln-208 before the M1 hydrophobic sequence, whereas the sample from the digest in trifluoroacetic acid also contained as a primary sequence a fragment beginning at Thr-244 and extending through the M2 hydrophobic sequence. Sequence analysis revealed no release of 3H for the sample from digestion in formic acid, whereas for the trifluoroacetic acid digest, there was specific release of 3H in cycle 19, which would correspond to Glu-262. This site of alkylation was confirmed by isolation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and reversed-phase HPLC of a specifically labeled fragment from an endoproteinase Lys-C digest of the alkylated alpha-subunit. NH2-terminal amino acid sequencing revealed release of 3H at cycle 20 from a fragment beginning at Met-243 and extending into the M3 hydrophobic sequence. Because [3H]meproadifen mustard contains, as its reactive group, a positively charged quaternary aziridinium ion, Glu-262 of the alpha-subunit is identified as a contributor to the cation-binding domain of the noncompetitive antagonist-binding site and thus of the ion channel.

GAP-43, a protein associated with axon growth, is phosphorylated at three sites in cultured neurons and rat brain

GAP-43 is a neuronal calmodulin-binding phosphoprotein that is concentrated in growth cones and presynaptic terminals. By sequencing tryptic and endoproteinase Asp-N phosphopeptides and directly determining the release of radioactive phosphate, we have identified three sites (serines 41 and 96 and threonine 172) that are phosphorylated, both in cultured neurons and in neonatal rat brain. These three sites account for most of the 32PO4 that was incorporated into GAP-43 in cultured neurons; 8-15% of each site was occupied with phosphate in GAP-43 isolated from neonatal rat brain. Phosphorylation of serine 41 in cultured neurons was stimulated by phorbol ester, indicating that it is the only site phosphorylated by protein kinase C. The resemblance of the sequence surrounding the other two sites suggests that they may be substrates for the same protein kinase. None of the sites phosphorylated by casein kinase II in vitro was phosphorylated in living cells or in neonatal rat brain. These results show that GAP-43 is a substrate for at least one protein kinase in addition to protein kinase C in living cells and brain.

Identification of six phosphorylation sites in the COOH-terminal tail region of the rat neurofilament protein M

The COOH-terminal tail domain of the neurofilament polypeptide M from rat nervous tissue contains approximately six molecules of phosphate. We report here that protein kinases in a crude cytoskeleton preparation of rat nervous tissue phosphorylated a set of tryptic peptides of M similar (but not identical) to those phosphorylated by living dorsal root ganglion cells in culture. Using these phosphopeptides as markers, we purified these same peptides from rat spinal cord and identified six specific phosphorylation sites in M by enzymatic and chemical criteria. These sites, serines 502, 506, 536, 606, 608, and 666, are all located in the COOH-terminal tail domain. Four are embedded in the repeated motif KSP whereas two are within variants of this motif, KSD and ESP. All of the sites that were preceded by lysine were resistant to alkaline phosphatase prior to modification of the lysine with citraconic anhydride. The identification of these sites should aid in investigations of the function of the phosphorylation of this protein and provides criteria for identifying the relevant kinases.

Potent anti-tumorigenic effect of tubeimoside 1 isolated from the bulb of Bolbostemma paniculatum (Maxim) Franquet

Tubeimoside 1, one of the new triterpenoid saponins from the bulb of Bolbostemma paniculatum (Maxim) Franquet, had an anti-inflammatory effect on mouse ear edema induced by arachidonic acid and 12-O-tetradecanoylphorbol-13-acetate (TPA). Furthermore, a potent anti-tumorigenic effect of tubeimoside 1 was observed in 2-stage carcinogenesis of mouse skin after oral administration as well as topical application. Thus, tubeimoside 1 appears to be a promising agent for cancer chemoprevention.

Structure of the agonist-binding site of the nicotinic acetylcholine receptor. [3H]acetylcholine mustard identifies residues in the cation-binding subsite

To characterize the structure of the agonist-binding site of the Torpedo nicotinic acetylcholine receptor (AChR), we have used [3H]acetylcholine mustard [( 3H]AChM), a reactive analog of acetylcholine, to identify residues contributing to the cation-binding subsite. Reaction of [3H]AChM, in its aziridinium form, with AChR-rich membrane suspensions, resulted initially in reversible, high affinity binding (K approximately 0.3 microM) followed by slow alkylation of the acetylcholine-binding site. Incorporation of label into AChR alpha-subunit was inhibited by agonists and competitive antagonists, but not by noncompetitive antagonists, and reaction with 3 microM [3H]AChM for 2 h resulted in specific alkylation of 0.6% of alpha-subunits. Within the alpha-subunit, greater than 90% of specific incorporation was contained within an 18-kDa Staphylococcus aureus V8 proteolytic fragment beginning at Val-46 and containing N-linked carbohydrate. To identify sites of specific alkylation, [3H]AChM-labeled alpha-subunit was digested with trypsin, and the digests were fractionated by reverse phase high pressure liquid chromatography. Specifically labeled material was recovered within a single peak containing a peptide extending from Leu-80 to Lys-107. NH2-terminal amino acid sequencing revealed specific release of 3H in cycle 14 corresponding to alpha-subunit Tyr-93. Identification of Tyr-93 as the site of alkylation was confirmed by radiosequence analysis utilizing o-phthalaldehyde to establish that the released 3H originated from a peptide containing prolines at residues 2 and 9. Because [3H]AChM contains as its reactive group a positively charged quaternary aziridinium, alpha-subunit Tyr-93 is identified as contributing to the cation-binding domain of the AChR agonist-binding site. The selective reaction of [3H]AChM with tyrosyl rather than acidic side chains indicates the importance of aromatic interactions for the binding of the quaternary ammonium group, and the lack of reaction with the tyrosyl or acidic side chains within alpha 190-200 emphasizes the selective orientation of acetylcholine within its binding site.

The major 35S-methionine-labeled rapidly transported protein (superprotein) is identical to SNAP-25, a protein of synaptic terminals

Superprotein is a rapidly axonally transported protein that is conspicuously labeled with 35S-methionine supplied to the cell bodies of retinal ganglion cells. Superprotein candidates are apparent among the rapidly transported proteins of many neurons from the CNS and PNS, including cranial, sympathetic, sensory, and motor neurons from mammals, fish, and amphibians. To determine the identity of Superprotein, we purified it from rabbit visual system and spinal cord and determined the amino acid sequence of seven of its tryptic peptides. The sequence shows that Superprotein is SNAP-25, a protein recently predicted from a cDNA sequence; SNAP-25 has been reported to be concentrated in the synaptic terminals of a selected population of CNS neurons. We measured the amount of radioactivity associated with Superprotein in tissue containing axons (optic tract) and synaptic terminals (superior collicules) of rabbit retinal ganglion cells. Labeled Superprotein disappeared from the superior colliculus more rapidly than another protein (synapsin I-like protein) that is concentrated in synaptic terminals. These results serve to unite the observations on the synthesis, distribution, metabolism, and axonal transport of Superprotein with observations of SNAP-25 and its mRNA.

Identification of serine 473 as a major phosphorylation site in the neurofilament polypeptide NF-L

Neurofilaments are composed of 3 polypeptides designated NF-H, NF-M, and NF-L, all of which are subject to posttranslational phosphorylation. It has been suggested that phosphorylation of the NF-L polypeptide can influence the assembly of NF-L into filaments, but the sites at which NF-L is phosphorylated are unknown. To locate these phosphorylation sites, we have identified phosphopeptides of NF-L by labeling them with 32P both in vitro and in cultured neurons and also by observing their change in chromatographic behavior after they have been treated with phosphatase. We report here that serine 473, in the carboxy-terminal tail domain of NF-L, is a major substrate in vitro for protein kinases endogenous to a crude cytoskeleton-containing fraction. Moreover, serine 473 is a major phosphorylation site in vivo; in neurofilaments isolated from rat spinal cord, approximately 73% of serine 473 was phosphorylated, and accounted for at least one-third of the total phosphate associated with NF-L. The identification of this phosphorylation site in NF-L provides a criterion for identifying the protein kinase that phosphorylates NF-L and raises the question of its function.

Cardiovascular effects of large doses of pentamorphone in the dog

The cardiovascular effects of large doses of pentamorphone were evaluated in nine mongrel dogs basally anesthetized with sodium thiopental, 25 to 30 mg/kg, intravenously. All dogs were mechanically ventilated with 100% oxygen, and the PaCO2 was maintained between 35 and 40 mm Hg. Mean arterial pressure (MAP), central venous pressure, heart rate (HR), cardiac output (CO), pulmonary artery pressure, and pulmonary artery occluded pressure were measured, and stroke volume and systemic and pulmonary vascular resistances were calculated. Baseline measurements were obtained, then pentamorphone, 10 micrograms/mL, was given as an intravenous infusion at 2.5 micrograms/kg/min. Additional data were obtained after infusion of 25, 50, 75, 100, 125, 150, 200, 250, 300, and 350 micrograms/kg of pentamorphone. The inspired gases were then changed to 50% nitrous oxide in oxygen, and after a 20-minute equilibration period, an additional set of data was collected. Pentamorphone, 25 micrograms/kg, decreased HR 50%, MAP 65%, and CO 54%. No further changes in any measured or calculated variables were observed with additional doses of pentamorphone. The addition of 50% nitrous oxide to the inspired gas mixture had no effect on any measured or calculated hemodynamic variable. The minimal hemodynamic effects of pentamorphone in the dog suggest that further investigation into its use as an anesthetic is warranted.

Synthetic peptide inhibitors of complement serine proteases--I. Identification of functionally equivalent protease inhibitor sequences in serpins and inhibition of C1s and D

Sequence homology comparisons between serum serine protease inhibitors led to the prediction that the C-terminal sequences are functionally equivalent and represent an essential protease binding domain. Inhibition of complement serine protease D cleavage of factor B and of C1s cleavage of C4 by synthetic peptides containing sequences from the C-termini of three serum serine protease inhibitors supports this prediction. These functionally equivalent peptides represent a new class of inhibitors of D and C1s as well as other serum serine proteases.

Synthetic peptide inhibitors of complement serine proteases--II. Effects on hemolytic activity and production of C3a and C4a

Synthetic peptides based on the amino acid sequence at the site of cleavage of C3 by classical and alternative pathway convertases were found to be poor inhibitors of hemolysis except at concns of 1 mM and higher. Synthetic peptides of a second type, based on the C-terminal sequence of antithrombin III, were more effective; the best among them caused significant inhibition of hemolysis at a concn of 5 microM. A hybrid peptide composed of the sequence at the site of cleavage of C4 by C1s attached to an antithrombin III sequence was selective, inhibiting the classical pathway with no effect on the alternative pathway at a concentration of 25 microM. Several of the antithrombin III peptides that inhibited hemolysis did not inhibit C4 activation by the classical pathway or activation of C3 by the classical and alternative pathways suggesting that these peptides affect hemolysis by inhibiting enzymes other than C1s and C4b2a of the classical pathway and C3bBb of the alternative pathway.

Comparison of sufentanil-N2O and fentanyl-N2O in patients without cardiac disease undergoing general surgery

Sufentanil (mean total dose 2 micrograms/kg) was compared with fentanyl (mean total dose 15 micrograms/kg) as a supplement to 60% N2O anesthesia in 30 adult patients undergoing general surgical procedures. Comparisons were made with respect to stability of hemodynamic variables (heart rate and systolic and diastolic blood pressure), changes in stress hormones (cortisol, antidiuretic hormone, epinephrine, norepinephrine, and dopamine), recovery of alertness and orientation, time to extubation, postoperative analgesia, and measures of respiratory depression (resting end-tidal carbon dioxide tension [PETCO2], CO2 response curve for minute ventilation [delta VE/delta PETCO2]). Hemodynamic variables remained stable and similar in both groups throughout the study. Plasma hormone levels remained similar to baseline in both groups until 1 h postoperatively when epinephrine levels were significantly elevated in both groups (P less than 0.05). Recovery times, including time to extubation, were similar in both groups. Patients given sufentanil had less pain 30 min postoperatively than those given fentanyl, although at 60 min postoperatively pain levels were similar in both groups. Small but significant elevations in resting PETCO2 were seen in both groups postoperatively (P less than 0.05), but postoperative delta VE/delta PETCO2 responses were significantly depressed only in patients receiving fentanyl (P less than 0.05). The results of this study demonstrate that sufentanil-N2O anesthesia is as effective as fentanyl-N2O in attenuating the hemodynamic and hormonal responses to the stress of general surgery. Because continuous intraoperative PETCO2 monitoring was not employed in this study, intraoperative hypocapnea cannot be strictly excluded as a possible influence on the postoperative measures of ventilatory drive.(ABSTRACT TRUNCATED AT 250 WORDS)