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Chronic myelogenous leukemia (CML) is a clonal disorder of a pluripotent hematopoietic stem cells characterized by a chimericbcr-ablgene giving rise to a p210Bcr-Ablprotein with dysregulated tyrosine kinase activity. Radicicol, a macrocyclic antifungal antibiotic, binds to the N-terminal of heat shock protein 90 (Hsp90) and destabilizes Hsp90-associated proteins such as Raf-1. This study investigated the effect of radicicol, novel oxime derivatives of radicicol (KF25706 and KF58333), and herbimycin A (HA), a benzoquinoid ansamycin antibiotic, on the growth and differentiation of human K562 CML cells. Although KF25706 and KF58333 induced the expression of glycophorin A in K562 cells, radicicol and HA caused erythroid differentiation transiently. Cell cycle analysis showed that G1phase accumulation was observed in K562 cells treated with KF58333. KF58333 treatment depleted p210Bcr-Abl, Raf-1, and cellular tyrosine phosphorylated proteins in K562 cells, whereas radicicol and HA showed transient depletion of these proteins. KF58333 also down-regulated the level of cell cycle–dependent kinases 4 and 6 and up-regulated cell cycle–dependent kinase inhibitor p27Kip1protein without an effect on the level of Erk and Hsp90 proteins. Immunoprecipitation analysis showed that p210Bcr-Ablformed multiple complexes with Hsp90, some containing p23 and others Hsp70; KF58333 treatment dissociated p210Bcr-Ablfrom Hsp90/p23 chaperone complexes. Furthermore, KF58333 induced apoptosis in K562 cells and administration of KF58333 prolonged the survival time of SCID mice inoculated with K562 cells. These results suggest that KF58333 may have therapeutic potential for the treatment of CML that involves abnormal cellular proliferation induced by p210Bcr-Abl.

• Whole blood serotonin concentrations were studied in 33 chronic schizophrenic patients who previously had computed tomographic (CT) brain scans and in 23 healthy volunteers. The chronic schizophrenic patients had a mean serotonin concentration significantly higher than that of the controls. The patients were subcategorized into a group with abnormal CT scan findings (enlargement of cerebral ventricles, cerebral atrophy, or both) and a group with normal CT scans. The patients with abnormal CT scans had significantly higher serotonin concentrations when compared with schizophrenics with normal CT scans and with controls. The chronic schizophrenic patients with normal CT scans did not have significantly elevated serotonin concentrations compared with controls. Furthermore, ventricular size in the total patient group was significantly correlated with serotonin concentration.

B cell neoplasms are clonal expansions of B lymphocytes thought to be frozen at various points along the normal B cell differentiation pathway. We studied cell suspensions from lymph nodes involved by follicular (nodular) non-Hodgkin' x2018;s lymphoma to determine the capacity of the malignant B cells to secrete immunoglobulin (Ig). Neoplastic B cells from all 14 follicular lymphomas secreted mono-clonal immunoglobulin in culture when appropriate signals were provided. In most cases, maximal Ig secretion occurred when autologous T cells were removed by E rosette depletion, replaced with allogeneic normal T cells, and the cultures were exposed to 12-O-tetradecanoylphor-bol-13-acetate. Autologous T cells exerted a suppressor effect on Ig secretion in 8/8 cases studied, diminishing the response of the malignant B cells to allogeneic T cells. This suppressor effect did not correlate with the percentage of cells staining with anti-Leu-2a or with “helper-suppressor” (Leu-3a-Leu-2a) ratios of the lymph node T cells. Our findings demonstrate that the arrested differentiation of most follicular lymphomas is reversible and implicate a T cell-mediated host immunoregulatory mechanism affecting Ig secretion in vivo. An additional contribution of our results is the demonstration of a cell culture system for synthesis of sufficient monoclonal Ig for use as an immunogen in production of anti-idiotype antibodies. © 1985 by Grune & Stratton, Inc.

β Plasma phenylalanine, tyrosine, and tryptophan concentrations were measured in chronic schizophrenic patients, normal controls, and heterozygotes for phenylketonuria. Schizophrenic patients'plasma concentrations of these amino acids could not be distinguished from those of normal controls, either when fasting or following oral or intravenous (IV) phenylalanine challenge. No neuroleptic effect was observed. Plasma phenylalanine-tyrosine ratios following IV phenylalanine challenge could easily distinguish heterozygotes from schizophrenic and normal control subjects but could not distinguish schizophrenic subjects from normal control subjects. No overlap between heterozygotes' values and those of the schizophrenic and normal subjects was observed. These studies find no evidence of abnormal phenylalanine metabolism in schizophrenic persons. Phenylalanine challenge did not affect the abstraction or judgment capacities of the subjects.

The expression of the interleukin-2 (IL-2) receptor was studied in neoplastic cells derived from acute leukemias, T-cell lymphoblastic lymphomas, peripheral T-cell lymphomas, chronic lymphocytic leukemias, well-differentiated lymphocytic lymphomas, and established cell lines by both flow cytometric analysis and sodium dodecyl sulfate/ polyacrylamide gel electrophoresis (SDS-PAGE) after affinity crosslinking of radiolabeled IL-2. Cells from most acute leukemias (19 of 22), irrespective of their subtype (T, common or nonlymphoid leukemias), as well as T-cell lymphoblastic lymphomas and peripheral T-cell lymphomas expressed only the p70-75 β subunit of the IL-2 receptor. Cells from the more mature B-cell neoplasms, chronic lymphocytic leukemia, and well-differentiated lymphocytic lymphoma, expressed predominately αβ IL-2 receptors (11 of 14). In contrast to these results, most cell lines established from hematopoietic malignancies do not express either chain of the IL-2 receptor. Further studies are necessary to determine the exact function of the IL-2R p70-75 β subunit in immature hematopoietic cells, but its wide distribution throughout the hematopoietic system suggests that IL-2 may play a role in the early stages of hematopoiesis.© 1989 by Grune & Stratton, Inc. 0006-4971/89/7307-0038$3.00/0

Initiation of T-lymphocyte proliferation by mitogen or antigen involves a cascade of gene activation events. Thus, by the time mitogen-activated T cells have reached the G1/S interface, many genes that are transcriptionally silent in GO, like the c-myc, IL-2, IL-2 receptor (IL-2R) and transferrin receptor (TfR) genes, have been transcriptionally activated1–4. To understand the role of the individual genes in the activation process, one must be able to interfere specifically with the expression or function of each particular gene product. In this way, by blocking the IL-2R with an antibody, it has been demonstrated that IL-2/IL-2R interaction is required to induce TfR expression in activated T cells3. When the function or expression of intracellular proteins is to be blocked, however, the need to introduce antibodies into the cytoplasm of viable cells, although possible5–7, is a limiting factor. We have taken another approach, namely the exogenous addition to bulk cell cultures of small antisense oligomers. Sequence-specific anti-sense oligodeoxyribonucleotides have been reported to inhibit intracellular viral replication without interfering with cellular protein synthesis8,9. Similarly, rabbit globin mRNA translation in a cell-free system and in rabbit reticulocytes has been inhibited by oligomers complementary to the globin mRNA initiation codon region10. Recently, a pentadecadeoxyribonucleotide complementary to the initiation codon and four downstream codons of human c-myc mRNA was reported to inhibit the proliferation of the human leukaemic cell line HL-60 specifically11. We report here that the same c-myc complementary oligonuelectide inhibits mitogen-induced c-myc protein expression in human T lymphocytes and prevents S phase entry. Interestingly, c-myc antisense treatment did not inhibit G0to G1traversal as assessed by morphologic blast transformation, transcriptional activation of the IL-2R and TfR genes, or induction of 3H-uridine incorporation.

The abundant, cytoplasmic 90-kDa heat-shock protein associates transiently with the Rous sarcoma virus oncogenic protein tyrosine kinase, pp60v-src, directs its cellular trafficking and negatively regulates its kinase activity. Here we report that the serine/threonine phosphatase inhibitor, okadaic acid, destabilized the heat-shock protein 90-pp60v-srcchaperone complex in v-src-transfected cells. Concomitant with complex destabilization by okadaic acid, phosphoserine was doubled and phosphothreonine was increased 20-fold in the heat-shock protein 90. Although phosphorylation of the total pool of immunoprecipitable pp60v-srcwas unchanged, okadaic acid slightly increased phosphoserine and phosphothreonine levels specifically in pp60v-srcbound to heat-shock protein 90. The low level of tyrosine phosphorylation in the pp60v-srccomplexed with heat-shock protein 90 was further decreased by okadaic acid. Interestingly, okadaic acid-stabilized hyperphosphorylation of the heat-shock protein 90-pp60v-srccomplex lowered the level of pp60v-srcin cell membranes, the functional location for pp60v-src. We suggest that serine/threonine phosphorylation of heat-shock protein 90 and/or pp60v-srcfunctions as a regulatory molecular trigger to release pp60v-srcfrom the chaperone complex at the inner surface of cell membranes.

The reliance of many cancers on aerobic glycolysis has stimulated efforts to develop lactate dehydrogenase (LDH) inhibitors. However, despite significant efforts, LDH inhibitors (LDHi) with sufficient specificity and in vivoactivity to determine whether LDH is a feasible drug target are lacking. We describe an LDHi with potent, on-target, in vivoactivity. Using hyperpolarized magnetic resonance spectroscopic imaging (HP-MRSI), we demonstrate in vivoLDH inhibition in two glycolytic cancer models, MIA PaCa-2 and HT29, and we correlate depth and duration of LDH inhibition with direct anti-tumor activity. HP-MRSI also reveals a metabolic rewiring that occurs in vivowithin 30 min of LDH inhibition, wherein pyruvate in a tumor is redirected toward mitochondrial metabolism. Using HP-MRSI, we show that inhibition of mitochondrial complex 1 rapidly redirects tumor pyruvate toward lactate. Inhibition of both mitochondrial complex 1 and LDH suppresses metabolic plasticity, causing metabolic quiescence in vitroand tumor growth inhibition in vivo.