HDAC1 and HDAC2 integrate the expression of p53 mutants in pancreatic cancer.

Mutation of p53 is a frequent genetic lesion in pancreatic cancer being an unmet clinical challenge. Mutants of p53 have lost the tumour-suppressive functions of wild type p53. In addition, p53 mutants exert tumour-promoting functions, qualifying them as important therapeutic targets. Here, we show that the class I histone deacetylases HDAC1 and HDAC2 contribute to maintain the expression of p53 mutants in human and genetically defined murine pancreatic cancer cells. Our data reveal that the inhibition of these HDACs with small molecule HDAC inhibitors (HDACi), as well as the specific genetic elimination of HDAC1 and HDAC2, reduce the expression of mutant p53 mRNA and protein levels. We further show that HDAC1, HDAC2 and MYC directly bind to the TP53 gene and that MYC recruitment drops upon HDAC inhibitor treatment. Therefore, our results illustrate a previously unrecognized class I HDAC-dependent control of the TP53 gene and provide evidence for a contribution of MYC. A combined approach targeting HDAC1/HDAC2 and MYC may present a novel and molecularly defined strategy to target mutant p53 in pancreatic cancer.

Effect of laryngoscopy and tracheal intubation on pulse pressure and influence of age on this response.

The study objective was to measure the change in pulse pressure associated with laryngoscopy and tracheal intubation and to relate these changes to trends in systolic, diastolic and mean blood pressure. The rationale was that the rise in systolic and diastolic blood pressure may be disproportionate and may result in either increase or decrease in pulse pressure. We also looked at the influence of age on this response. This prospective observational study measured the changes in pulse pressure secondary to laryngoscopy and tracheal intubation in eighty adult surgical patients. Two groups of forty patients each were included, young (group A) 18-25 years and middle-aged (group B) 45-55 years. The patients were ASA Class 1 or 2, of either gender and non-hypertensive. Systolic, diastolic, and mean blood pressure, and heart rate were measured preinduction and 1, 2 and 3 minutes after induction. Thereafter they were measured every minute for five minutes after intubation. Pulse pressure was obtained by subtracting the diastolic from the systolic blood pressure. No pulse pressure change occurred in the young group despite of a significant increase in both systolic and diastolic blood pressures. The middle aged group showed an average rise of +18 mm of Hg in pulse pressure (taken at 1 minute post-intubation) compared to the baseline measurement (P<0.0001). These changes in pulse pressure during anaesthesia may indicate an additional pulsatile stress in vulnerable patients in addition to the changes associated with resistance alone and need to be studied further.

Bis(1H-2-indolyl)-1-methanones as inhibitors of the hematopoietic tyrosine kinase Flt3.

Aberrant expression and activating mutations of the class III receptor tyrosine kinase Flt3 (Flk-2, STK-1) have been linked to poor prognosis in acute myeloid leukemia (AML). Inhibitors of Flt3 tyrosine kinase activity are, therefore, of interest as potential therapeutic compounds. We previously described bis(1H-2-indolyl)-1-methanones as a novel class of selective inhibitors for platelet-derived growth factor receptors (PDGFR). Several bis(1H-2-indolyl)-1-methanone derivatives, represented by the compounds D-64406 and D-65476, are also potent inhibitors of Flt3. They inhibit proliferation of TEL-Flt3-transfected BA/F3 cells with IC(50) values of 0.2-0.3 microM in the absence of IL-3 but >10 microM in the presence of IL-3. Ligand-stimulated autophosphorylation of Flt3 in EOL-1 cells and corresponding downstream activation of Akt/PKB are effectively inhibited by bis(1H-2-indolyl)-1-methanones whereas autophosphorylation of c-Kit/SCF receptor or c-Fms/CSF-1 receptor is less sensitive or insensitive, respectively. Flt3 kinase purified by different methods is potently inhibited in vitro, demonstrating a direct mechanism of inhibition. 32D cells, expressing a constitutively active Flt3 variant with internal tandem duplication are greatly sensitized to radiation-induced apoptosis in the presence of D-64406 or D-65476 in the absence but not in the presence of IL-3. Thus, bis(1H-2-indolyl)-1-methanones are potential candidates for the treatment of Flt3-driven leukemias.

Synthetic 2-aroylindole derivatives as a new class of potent tubulin-inhibitory, antimitotic agents.

A new class of simple synthetic antimitotic compounds based on 2-aroylindoles was discovered. (5-Methoxy-1H-2-indolyl)-phenylmethanone (1) as well as analogous 3-fluorophenyl- (36) and 3-methoxyphenyl (3) derivatives displayed high cytotoxicity of IC(50) = 20 to 75 nM against the human HeLa/KB cervical, SK-OV-3 ovarian, and U373 astrocytoma carcinoma cell lines. The inhibition of proliferation correlated with the arrest in the G2/M phase of the cell cycle. In in vitro assays with tubulin isolated from bovine brain, in general antiproliferative activity correlated with inhibition of tubulin polymerization. Thus, the antimitotic activity of 2-aroylindoles is explained by interference with the mitotic spindle apparatus and destabilization of microtubules. In contrast to colchicine, vincristine, nocodazole, or taxol, 1 did not significantly affect the GTPase activity of beta-tubulin. Interestingly, selected compounds inhibited angiogenesis in the chorioallantoic membrane (CAM) assay. In xenograft experiments, 1 was highly active after oral administration at 200 mg/kg against the human amelanocytic melanoma MEXF 989 in athymic nude mice. We conclude, that 2-aroylindoles constitute an interesting new class of antitubulin agents with the potential to be clinically developed for cancer treatment.

Pyrrolo[3,4-c]-beta-carboline-diones as a novel class of inhibitors of the platelet-derived growth factor receptor kinase.

Members of the structurally diverse family of beta-carbolines have previously been shown to exhibit a wide range of biological activities. A novel synthetic strategy for generation of beta-carbolines was developed, allowing imido-beta-carbolines to be created in three steps from known compounds. The compounds were screened for inhibition of platelet-derived growth factor (PDGF)-stimulated tyrosine phosphorylation in Swiss 3T3 fibroblasts. A number of the newly synthesized beta-carbolines with moderate to potent inhibitory activity were revealed. The most active derivative, 2,3-dihydro-8,9-dimethoxy-5-(2-methylphenyl)-1H,6H-pyrrolo[3, 4-c]pyrido¿3,4-bindole-1,3-dione 2ee, inhibited purified PDGF receptor kinase and PDGF-receptor autophosphorylation in intact cells with IC(50) values of 0.4 and 2.6 microM, respectively. Dione 2ee also inhibited PDGF-stimulated DNA synthesis in Swiss 3T3 fibroblasts with an IC(50) of 3.2 microM. The compound had no effect on Src or epidermal growth factor (EGF) receptor kinase activity and a six-seven-fold higher IC(50) for inhibition of basic fibroblast growth factor (bFGF)-stimulated tyrosine phosphorylation or Kit/stem cell factor (SCF) receptor autophosphorylation, indicating a reasonable extent of kinase specificity. Thus, beta-carbolines present a new lead of tyrosine kinase inhibitors with the capacity to selectively interfere with PDGF receptor signal transduction and PDGF-dependent cell growth.

Synthesis and biological evaluation of 4,4-dimethyl-5,5-di(1-methylethyl)-2,3,4,5-tetrahydro-1 H-dipyrrolo[3,4-d:2,1-f][1,2]azasiline-1,3-dione and other pyrrolediones as new antibacterial active agents.

The UV-light induced photosubstitution of 3,4-dibromo-2,5-dihydro-1H-2,5-pyrroledione (2) [1] with pyrrole derivatives leads to 3-mono- and 3,4-disubstituted pyrrolediones depending on the starting material. These pyrrole homologues of arcyriarubin A (1) are further processed by nucleophilic substitution of the remaining bromine substitutent with pyrrolidine. Cleavage of the protecting group affords the free pyrrole substituents. By UV-light irradiation the azasiline-system (6) is accessible, and its structure was established by X-ray methods. The in vitro antibacterial activity of the pyrrolediones was evaluated, and a strong activity of the compounds 4, 7, 8 and 12 against the methicillin- and ciprofloxacin-resistant bacterium Staphylococcus aureus 134/94 was established.

beta-Carbolinedione derivatives as topoisomerase I inhibitors.

Pyrrolo[3,4-c]-beta-carbolinedione dimers 5-14 were synthesized from furo[3,4-c]-beta-carbolinediones and diamines by solvent-free TaCl5/silica catalyzed reaction under microwave irradiation. The inhibitory property of these target compounds, the starting materials 2, 31, 32, and the N-alkylated pyrrolo[3,4-c]-beta-carbolinediones 16, 17, 20-30 was tested against the relaxation of supercoiled pRB322 DNA by calf thymus topoisomerases I and II. Some of these compounds, especially 7 and 23 proved to be selective inhibitors of topoisomerase I.

Synthesis of enantiomerically pure (-)-(S)-brevicolline

(-)-(S)-Brevicolline (1) and related beta-carbolines were synthesized using an enantiomerically pure Michael-acceptor synthon (3). Subsequent Pictet-Spengler reaction afforded the tetrahydro-beta-carboline skeleton, which, in turn, was transformed to the beta-carboline by catalytic dehydrogenation.

[Synthesis of carbazole derivatives. 1. The reaction of 3-(2-nitroethenyl)-indole-2-malonic acid esters with Michael acceptors]. / Uber die Reaktion von 3-(2-Nitroethenyl)indol-2-malonestern mit Michael-Akzeptoren.

Michael-type reaction of compounds of type 9 were studied. Addition reactions with acrolein and methyl vinyl ketone, respectively, lead--depending on the conditions--to pyridoindoles of type 16 and 14 and/or to tetrahydrocarbazoles of type 17 and 15. With Triton B compounds 15 undergo retro-Michael-type elimination of the nitromethyl group, followed by hydrolysis/decarboxylation and dehydrogenation, leading to the disubstituted carbazoles 20. In the case of 17a, the primary elimination product 18 could be isolated. The synthetic potential of these reaction types is discussed. Some of the described compounds and derivatives of them show antimycobacterial activity.

[Antimycobacterial acting carbazole derivatives]. / Antimycobakteriell wirksame Carbazolderivate.

Carbazoles are synthesized and tested for antimycobacterial properties (M. tuberculosis H 37 Ra, Middlebrook-7H9-broth). The different antimycobacterial properties of diastereomeres are examined using compounds 32 and 33, those of a racemic compound and the (+)-enantiomer are tested with (+/-)-12/(+)-12 and (+/-)-5/(+)-5, respectively. (+)-12 is prepared by enantioselective synthesis.

[3-Substituted 2-phenylindoles: synthesis and biological properties]. / 3-Substituierte 2-Phenylindole: Synthese und biologische Eigenschaften.

Knoevenagel-reaction of indol-3-carbaldehydes 5a,b and 7a,b with nitromethane leads to the nitroethenes 12 and 14, the analogous reaction with malodinitrile to the methylidenemalonic acid dinitriles 16.- Michael-addition of nitromethane at 12 and 14 affords the 1,3-dinitropropanes 13 and 15, reduction of 16 the methylmalonic acid dinitriles 17.- Reaction of indoles 3 with n-BuLi/phenylsulfonylchloride leads to the 3-chloroindoles 18, reaction with NaH/ethyliodide, either cleavage and acylation to derivatives 19.- Compounds 7-11, 14-17, and 19 show affinity to the estrogen receptor. Compounds 7b, 9-11, 17b, and 19b inhibit the growth of MCF-7- and MDA-MB-231-cells. IC50-values are determined and structure-activity relationships are discussed.

[Antimycobacterial indole derivatives]. / Antimykobakteriell wirksame Indolderivate.

1,3-Dinitro-2-(indol-3'-yl)-propanes 3 are synthesized by Michael reaction of nitromethane with the indolylnitroethenes 2. Reaction of the aldehydes 4 and 10 with the benzylamines 12 as well as the reaction of the indolylalkylamines 6a and 9a with the benzaldehydes 11 lead to Schiff bases which are reduced to N-benzyl-(indol-3-ylmethyl)-amines 13 and N-benzyl-(indol-3-ylethyl)-amines 14, respectively; tert amines 16 are synthesized via the formamides 15, amines 18 are prepared according to Mannich. Inhibitory effects on Mycobacterium tuberculosis H 37 Ra are investigated, a structure-activity relationship is discussed.