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Abstract Background Aberrant expression of cyclin D1 is a common feature in multiple myeloma (MM) and always associated with mantle cell lymphoma (MCL). CCND1 gene is alternatively spliced to produce two cyclin D1 mRNA isoforms which are translated in two proteins: cyclin D1a and cyclin D1b. Both isoforms are present in MM cell lines and primary cells but their relative role in the tumorigenic process is still elusive. Results To test the tumorigenic potential of cyclin D1b in vivo, we generated cell clones derived from the non-CCND1 expressing MM LP-1 cell line, synthesizing either cyclin D1b or cyclin K, a structural homolog and viral oncogenic form of cyclin D1a. Immunocompromised mice injected s.c. with LP-1K or LP-1D1b cells develop tumors at the site of injection. Genome-wide analysis of LP-1-derived cells indicated that several cellular processes were altered by cyclin D1b and/or cyclin K expression such as cell metabolism, signal transduction, regulation of transcription and translation. Importantly, cyclin K and cyclin D1b have no major action on cell cycle or apoptosis regulatory genes. Moreover, they impact differently cell functions. Cyclin K-expressing cells have lost their migration properties and display enhanced clonogenic capacities. Cyclin D1b promotes tumorigenesis through the stimulation of angiogenesis. Conclusions Our study indicates that cyclin D1b participates into MM pathogenesis via previously unrevealed actions.

Evidence from clinical and laboratory studies suggests that angiogenesis is important in the progression of solid tumours and hematologic malignancies. We have shown that the naturally occurring tetrapeptide Acetyl-Ser-Asp-Lys-Pro (AcSDKP) is a potent angiogenic factor normally present at nanomolar concentrations in the blood. A murine leukemia model was used to assess whether there was a correlation between levels of endogenous AcSDKP and the development of disease. Levels of AcSDKP in the plasma and bone marrow (BM) cells from mice bearing an acute myeloid leukemia (AML) were five- to ten-fold greater than those in non-leukemic mice. Furthermore, a strong correlation between the concentration of endogenous AcSDKP and the progression of AML was demonstrated. These results are consistent with the marked increase in BM vascularity observed in leukemic mice. The physiologic relevance of these findings awaits further studies and the contribution of AcSDKP to the pathogenesis of leukemia is under investigation. [ABSTRACT FROM AUTHOR]

The tetrapeptide acetyl-serine-aspartyl-lysine-proline (AcSDKP) has recently been recognized as a potent angiogenic factor. Given the importance of vascular blood supply in the process of tissue repair we have investigated the ability of AcSDKP to contribute to the repair of cutaneous injuries by using dorsal and abdominal skin flap models. Postoperative subdermal AcSDKP injections (5 μg/kg/injection twice a day for 3 days following flap elevation) prevented marginally perfused areas from undergoing necrosis. Mean skin survival area of abdominal and dorsal flaps ranged, respectively, from 50.9±19.3 and 53.4±4.2% in the control groups to 66.4±7.5 and 74.7±6.6% in AcSDKP-treated groups. Furthermore, in an ex vivo assay, AcSDKP applied locally to skin explants at doses from 10−8 to 10−5 M improved survival of the explanted skin exposed to UVB irradiation at 10 J/cm2. Increased reepithelialization, as well as higher levels of expression of basal keratin 14 and increased expression of fibronectin was observed after topical application of AcSDKP. These data provide experimental evidence that AcSDKP can improve the viability of ischemic skin flaps in the rat by promoting angiogenesis. Moreover, it enhances wound healing of injured avascular skin explants. Thus, these findings identify AcSDKP as a new tissue-repair agent and suggest its potential clinical use for the management of skin wounds. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented commenting on the role of angiogenesis in the pathogenesis of different non-solid hematologic malignancies.

Matrix metalloproteinases (MMPs) play an important role in cancer metastasis. Here, we investigated the effect of fibroblast growth factor-2 (FGF-2) and 12-O-tetradecanoylphorbol-13-acetate (TPA) on the secretion of type IV collagenases (MMP-2, MMP-9) in breast cancer MCF-7 cells. As shown by gelatin zymography, both FGF-2 and TPA stimulated the secretion of MMP-9 in MCF-7 cells while they did not change the level of MMP-2 secretion. Signaling cascade studies indicated that both FGF-2 and TPA induced Ras activation, c-Raf phosphorylation, mitogen-activated protein kinase/ERK kinase (MEK1/2) phosphorylation, and extracellular signal-regulated kinase (ERK1/2) phosphorylation. The FGF-2- and TPA-induced MMP-9 secretion was significantly inhibited by transient transfection of MCF-7 cells with dominant negative Ras (Ras-N17) and by treatment with MEK1/2 inhibitor PD98059. A pan-protein kinase C (PKC) inhibitor, GF109203X, was found to totally abolish the FGF-2- and TPA-induced MMP-9 secretion and ERK1/2 phosphorylation. Use of isoform-specific PKC inhibitors such as Rotllerin and Go¨6976 suggested, moreover, that the PKC-δ isoform is a likely component of FGF-2 and TPA trophic signaling. These results demonstrated that FGF-2 and TPA induce MMP-9 secretion in MCF-7 cells mainly through PKC-dependent activation of the Ras/ERK1/2 signaling pathway. [Copyright &y& Elsevier]

Thermoresponsive behavior of different kinds of polymersomes was studied using small angle neutron scattering (SANS), transmission electron microscopy (TEM), and proton nuclear magnetic resonance ((1)H NMR). The polymersomes were made of block copolymers containing a 2000 Da polyethylene glycol (PEG) as a hydrophilic block and either a liquidlike polymer (e.g., PBA: polybutylacrylate), a solidlike polymer (PS: polystyrene), or a liquid crystalline (LC) polymer as a hydrophobic block. Structural changes in polymersomes are driven in all cases by the critical dehydration temperature of PEG corona, which is closely related to the chemical structure and chain mobility of the hydrophobic block. No structural changes occur upon heating from 25 to 75 °C in the liquidlike polymersomes where the critical dehydration temperature of PEG should be higher than 75 °C. In contrast, glassy PEG-b-PS polymersomes and LC polymersomes show structural changes around 55 °C, which corresponds to the critical dehydration temperature of PEG in those block copolymers. Furthermore, the structural changes depend on the properties of the hydrophobic layer. Glassy PEG-b-PS polymersomes aggregate together above 55 °C, but the bilayer membrane is robust enough to remain intact. This aggregation is reversible, and rather separate polymersomes are recovered upon cooling. However, LC polymersomes display drastic and irreversible structural changes when heated above ∼55 °C. These changes are dependent on the LC structures of the hydrophobic layer. Nematic LC polymersomes turn into thick-walled capsules, whereas smectic LC polymersomes collapse into dense aggregates. As these drastic and irreversible changes decrease or remove the inner compartment volume of the vesicle, LC polymersomes can be used for thermal-responsive controlled release, as shown by a study of calcein release. Finally, toxicity studies proved that LC polymersomes were noncytotoxic and had no effect on cell morphology.

Background: Aberrant expression of cyclin D1 is a common feature in multiple myeloma (MM) and always associated with mantle cell lymphoma (MCL). CCND1 gene is alternatively spliced to produce two cyclin D1 mRNA isoforms which are translated in two proteins: cyclin D1a and cyclin D1b. Both isoforms are present in MM cell lines and primary cells but their relative role in the tumorigenic process is still elusive., Results: To test the tumorigenic potential of cyclin D1b in vivo, we generated cell clones derived from the non-CCND1 expressing MM LP-1 cell line, synthesizing either cyclin D1b or cyclin K, a structural homolog and viral oncogenic form of cyclin D1a. Immunocompromised mice injected s.c. with LP-1K or LP-1D1b cells develop tumors at the site of injection. Genome-wide analysis of LP-1-derived cells indicated that several cellular processes were altered by cyclin D1b and/or cyclin K expression such as cell metabolism, signal transduction, regulation of transcription and translation. Importantly, cyclin K and cyclin D1b have no major action on cell cycle or apoptosis regulatory genes. Moreover, they impact differently cell functions. Cyclin K-expressing cells have lost their migration properties and display enhanced clonogenic capacities. Cyclin D1b promotes tumorigenesis through the stimulation of angiogenesis., Conclusions: Our study indicates that cyclin D1b participates into MM pathogenesis via previously unrevealed actions.

The natural tetrapeptide acetyl-ser-asp-lys-pro (AcSDKP) is formed in vivo by enzymatic cleavage of the N terminus of thymosin beta4 by prolyl oligopeptidase (POP). Recently, AcSDKP was shown to promote angiogenesis. Because of the critical role of neovascularization in cancer development, the levels of AcSDKP and POP activity in a number of different malignant tissues were investigated. Our studies revealed that AcSDKP levels were markedly elevated in neoplastic diseases including hematologic malignancies and solid neoplasms. Consistent with this finding, the enhanced activity of POP was also detected in all analyzed specimens of cancer tissues. Both these novel findings are in concert with the previously reported overexpression of thymosin beta4 in a large variety of malignant tumors and with its potential role in cancerogenesis. The physiological relevance of these findings awaits further studies; however, our first results strongly suggest a key role for AcSDKP in the pathogenesis of cancer.

Herein is reported a convergent synthesis of isocombretastatins A, a novel class of potent antitubulin agents. These compounds having a 1,1-diarylethylene scaffold constitute the simplest isomers of natural Z-combretastatins A that are easy to synthesize without need to control the Z-olefin geometry. The discovery of isoCA-4 with biological activities comparable to that of CA-4 represents a major progress in this field.

Background: The putative pharmacophore of a naturally cytotoxic limonoid haperforin B1, E-5-iodomethylene-6,6-dimethyl-5,6-dihydropyran-2-one (IDDP) was synthesized and its biological activity was investigated., Materials and Methods: The cytotoxicity of IDDP was assessed using human breast, lung, colorectal and epidermal carcinomas, chronic myeloid leukemia and glioblastoma cell lines. Cell cycle analysis was performed by flow cytometry. The induction of apoptosis was studied by a caspase assay and by annexin V-propidium iodide double staining. The organization of actin and tubulin microfilaments was analysed by immunocytochemical labeling., Results: IDDP was shown to inhibit the growth of a panel of human cancer cell lines independently of their p53 status with IC(50) ranging from 0.07 to 0.50 microM. All the treated cells were arrested in the G(2)/M phase in a time-dependent manner before cell death occurred through an apoptotic pathway. Immunocytochemical studies revealed that the normal organization of microfilaments and microtubules was disrupted in IDDP exposed cells., Conclusion: IDDP can be considered as a promising anticancer agent.

Background: The natural tetrapeptide acetyl-Ser-Asp-Lys-Pro (AcSDKP), generated from thymosin beta4 following its cleavage by prolyl oligopeptidase (POP), is a physiological stimulator of angiogenesis. Because of the critical role of neovascularisation in tumor development, the expression of AcSDKP and the activity of POP were examined in different human solid malignancies., Materials and Methods: The expression of AcSDKP and the activity of POP were evaluated in human blood samples and tissue specimens of thyroid goiter and thyroid papillary carcinoma as well as in commercial cancer tissue microarray., Results: A significantly increased concentration of AcSDKP in intratumoral blood and enhanced tissular activity of POP were detected in cancer patients. The expression of AcSDKP in human breast, colon, head and neck, kidney, lung, skin, ovary and prostate cancer tissues was shown to be greater than that in normal tissues., Conclusion: AcSDKP and POP contribute to the malignant phenotype and these molecules are potentiel markers of cancer.

A series of 5-alkylindolobenzazepin-7-ones was synthesized by Suzuki coupling between 3-iodoindole-2-carboxylates and the appropriate alpha-alkylbenzylamino o-boronic acids followed by cyclization to the lactam. Derivatives having a linear alkyl chain at C5 were found to be highly cytotoxic to KB cells with IC50 values in the 30-80 nM range. These compounds also inhibited the polymerization of tubulin with IC50's of 1-2 microM. Compound 4f (( S)-5-ethyl) showed comparable antiproliferative activities (IC50's of 30-70 nM) in a variety of cancer cell lines, cell growth being arrested at the G2/M phase. Compound 4f induced apoptosis in a dose-dependent manner in three different cancer cell lines and was shown to affect cell morphology in a manner consistent with its inhibitory action on tubulin polymerization. Using the experimental model of glioma grafted on the chick chorio-allantoic membrane, local treatment with compound 4f markedly reduced tumor progression.

Background: Multiform glioblastomas represent the most aggressive brain tumors. Here, the cooperative effects of sodium phenylacetate (NaPa) and/or tamoxifen (TAM) on CNS1 and 9L glioblastoma cell lines in vitro and in an experimental animal tumor model were investigated., Materials and Methods: The drug effects on cell cycle and apoptosis were investigated by flow cytometry. CNS1 cells were implanted subcutaneously in nude mice to form tumors which were then treated with NaPa, TAM or NaPa/TAM., Results: A significant inhibitory effect of NaPa on the two glioma cell lines (LD50 of 10 mM) was observed. 10(-5) M of TAM inhibited approximately 35% of 9L cell growth, and 90% of CNS1 cell growth. When a combination of both drugs included 10(-9) M of TAM, inhibition of about 50% of 9L cell growth and 75% of CNS1 cell growth occurred. The NaPa/TAM combined treatment increased the number of G0/G1 arrested cells and apoptotic cells as compared to treatments with NaPa or TAM alone. Inhibition of CNS1 tumor growth were observed after a two week treatment with NaPa (32 mg/kg/day) or TAM (6 mg/kg/day)., Conclusion: These results showed a synergistic effect between these two drugs on tumor cell proliferation, caused by cell cycle arrest in the G0/G1 phase and by induction of apoptosis.

The asymmetric synthesis of novel axially chiral biaryl compounds 5 a-f containing a seven- or eight-membered heterocyclic medium ring is described. These molecules can be considered to be structural hybrids of allocolchicine- and steganacin-type natural products. The synthesis featured an atropo-diastereoselective biaryl Suzuki coupling in which a benzylic stereocenter efficiently transferred its stereochemical information to the biaryl axis. The coupling conditions were optimized, and two biphenylphosphane ligands (DavePhos and S-Phos) were found to give the highest yields and diastereoselectivities. A three-element stereochemical model was proposed to explain the observed diastereoselectivities. In a second key step, the medium ring of the target molecules was formed by a stereoselective S(N)1-type cyclodehydration that probably involved a configurationally stable carbocationic intermediate, as supported by calculations. Alternatively, S(N)2-type cyclizations were employed on the same Suzuki coupling products to give the target molecules in a stereodivergent or stereoconvergent manner. These cyclization methods furnished the target hybrid analogues 5 a-f with ee values above 94 %. All analogues were evaluated as antimicrotubule agents and against a panel of cancer-cell lines using colchicine (1) and N-acetylcolchinol (3) as references. Promising activities were found for R,aR-configured compounds 5 a, b and 5 f; in particular, ethyl analogue 5 b showed a twofold antimicrotubule activity relative to colchicine.

Background: We investigated the putative proangiogenic activity and molecular pathway(s) of the tetrapeptide acetyl-N-Ser-Asp-Lys-Pro (AcSDKP) in a model of surgically induced hindlimb ischemia., Methods and Results: Hindlimb ischemia was induced by femoral artery ligature and an osmotic minipump was implanted subcutaneously to deliver low (0.12 mg/kg per day) or high (1.2 mg/kg per day) doses of AcSDKP, for 7 or 21 days. Angiography scores, arteriole density, capillary number, and foot perfusion were increased at day 21 in the high-dose AcSDKP-treated mice (by 1.9-, 1.8-, 1.3-, and 1.6-fold, respectively) compared with control animals (P<0.05, P<0.01, P<0.01, respectively). AcSDKP treatment for 24 hours upregulated the monocyte chemoattractant protein-1 (MCP-1) mRNA and protein levels by 1.5-fold in cultured endothelial cells (P<0.01). In the ischemic hindlimb model, administration of AcSDKP also enhanced MCP-1 mRNA levels by 90-fold in ischemic leg (P<0.001) and MCP-1 plasma levels by 3-fold (P<0.001 versus untreated ischemic control mice). MCP-1 levels upregulation were associated with a 2.3-fold increase in the number of Mac3-positive cells in ischemic area of AcSDKP-treated mice (P<0.001 versus untreated animals). Interestingly, AcSDKP-induced monocyte/macrophage infiltration and postischemic neovascularization was fully blunted in MCP-1-deficient animals., Conclusions: AcSDKP stimulates postischemic neovascularization through activation of a proinflammatory MCP-1-related pathway.

Fucoidans inhibit tumour cell adhesion to various substrata, but their mechanisms of action are not fully understood. Using 3H-fucoidan, we observed that fucoidan binds to fibronectin, this binding being saturable and sensitive to ionic strength and pH. The interaction occurred on at least four different sites along the polypeptide chain, two of them being the heparin-binding sequences. Moreover, when MDA-MB-231 tumour cells were exposed to DTAF-fucoidan, internalization occurred and punctuated vesicles were observed in the perinuclear region. The treated cells also showed a different morphology with a cytoskeleton devoid of vinculin and a reorganiztion of the repartition of the integrin-alpha5 subunit on the cell surface. Based on these data, we hypothesize that fucoidan inhibits the adhesion of MDA-MB-231 cells to fibronectin i) by blocking the protein's heparin- and cell-binding domains, ii) by modulating the reorganization of the integrin alpha5 subunit and iii) by down-regulating the expression of vinculin.