MAF1, a repressor of RNA polymerase III-dependent transcription, regulates bone mass.

MAF1, a key repressor of RNA polymerase (pol) III-mediated transcription, has been shown to promote mesoderm formation in vitro. Here, we show that MAF1 plays a critical role in regulating osteoblast differentiation and bone mass. Global deletion of ( mice) produced a high bone mass phenotype.

Inhibition of GATA2 in prostate cancer by a clinically available small molecule.

Castration-resistant prostate cancer (CRPC) remains highly lethal and in need of novel, actionable therapeutic targets. The pioneer factor GATA2 is a significant prostate cancer (PC) driver and is linked to poor prognosis. GATA2 directly promotes androgen receptor (AR) gene expression (both full-length and splice-variant) and facilitates AR binding to chromatin, recruitment of coregulators, and target gene transcription.

Myxoma Virus-Loaded Mesenchymal Stem Cells in Experimental Oncolytic Therapy of Murine Pulmonary Melanoma.

Oncolytic viruses can target neoplasms, triggering oncolytic and immune effects. Their delivery to melanoma lesions remains challenging. Bone-marrow-derived mesenchymal stem cells (MSCs) were shown to be permissive for oncolytic myxoma virus (MYXV), allowing its transfer to melanoma cells, leading to their killing.

Structure-bioavailability relationship study of genistein derivatives with antiproliferative activity on human cancer cell.

The present study assesses the in vitro and in vivo bioavailability of genistein derivatives, hydroxyalkyl- and glycosyl alkyl ethers (glycoconjugates). Studies were carried out using compounds that exhibit higher in vitro antiproliferative activity in comparison with the parent isoflavone. Based on in vitro experiments using the Parallel Artificial Membrane Permeability Assay (PAMPA) and the Caco-2 cell monolayer permeability model, we found that modification of the isoflavone structure by O-alkylation improved bioavailability in comparison to genistein.

The RNA polymerase III repressor MAF1 is regulated by ubiquitin-dependent proteasome degradation and modulates cancer drug resistance and apoptosis.

MAF1 homolog, negative regulator of RNA polymerase III (MAF1) is a key repressor of RNA polymerase (pol) III-dependent transcription and functions as a tumor suppressor. Its expression is frequently down-regulated in primary human hepatocellular carcinomas (HCCs). However, this reduction in MAF1 protein levels does not correlate with its transcript levels, indicating that MAF1 is regulated post-transcriptionally.

Isoflavones, their Glycosides and Glycoconjugates. Synthesis and Biological Activity.

Glycosylation of small biologically active molecules, either of natural or synthetic origin, has a profound impact on their solubility, stability, and bioactivity, making glycoconjugates attractive compounds as therapeutic agents or nutraceuticals. A large proportion of secondary metabolites, including flavonoids, occur in plants as glycosides, which adds to the molecular diversity that is much valued in medicinal chemistry studies. The subsequent growing market demand for glycosidic natural products has fueled the development of various chemical and biotechnological methods of glycosides preparation.

Bis-anthracycline WP760 abrogates melanoma cell growth by transcription inhibition, p53 activation and IGF1R downregulation.

Anthracycline chemotherapeutics, e.g. doxorubicin and daunorubicin, are active against a broad spectrum of cancers.

Absorption and metabolism of biologically active genistein derivatives in colon carcinoma cell line (Caco-2).

Several genistein derivatives comprising an isoflavonoid skeleton substituted with an alkyl chain and a sugar moiety show ability to inhibit proliferation of cancer cells in vitro at the concentration several-fold lower than genistein. In our previous studies we shown that these compounds influenced the mitotic spindle, blocked the cell cycle and induced apoptosis. The purpose of this study was to determine the relationship between structural modifications of genistein molecule and the intestinal disposition of its derivatives.

Synthetic genistein glycosides inhibiting EGFR phosphorylation enhance the effect of radiation in HCT 116 colon cancer cells.

The need to find new EGFR inhibitors for use in combination with radiotherapy in the treatment of solid tumors has drawn our attention to compounds derived from genistein, a natural isoflavonoid. The antiproliferative potential of synthetic genistein derivatives used alone or in combination with ionizing radiation was evaluated in cancer cell lines using clonogenic assay. EGFR phosphorylation was assessed with western blotting.

Synthesis and cytotoxicity of 2,3-enopyranosyl C-linked conjugates of genistein.

A series of glycoconjugates, derivatives of genistein containing a C-glycosylated carbohydrate moiety, were synthesized and their anticancer activity was tested in vitro in the human cell lines HCT 116 and DU 145. The target compounds 15-17 were synthesized by treating ω-bromoalkyl C-glycosides derived from L-rhamnal (1) with a tetrabutylammonium salt of genistein. The new, metabolically stable analogs of previously studied O-glycosidic genistein derivatives inhibited proliferation of cancer cell lines through inhibition of the cell cycle.

[Three-dimensional cell cultures. Applications in basic science and biotechnology].

The tissue culture technique is widely used in biochemical and molecular studies, offering accessibility to biological material, high reproducibility of results and high throughput format, comparing with organ cultures. However, traditional, two-dimensional cultures (2D cultures) poorly represent the microenvironment of a tissue, and they are gradually replaced with 3D cultures, that enable formation of intercellular contacts, signaling pathways and gene expression characteristic for tissue in vivo. This paper presents the biology of three-dimensional cultures (spheroids), their applications in basic science and biotechnology and methods of spheroids formation.

Association of circulating regulatory T cell number with the incidence and prognosis of diffuse large B-cell lymphoma.

Regulatory T (Treg) cells are essential for maintaining immune tolerance. High Treg frequencies have been reported in peripheral blood and tissue samples of patients with solid tumors while their role in lymphomas, including diffuse large B-cell lymphoma (DLBCL) has not been clearly established. In this study, we analyzed the circulating Treg numbers in 27 patients with newly diagnosed DLBCL and 17 healthy individuals.

Synthesis of genistein 2,3-anhydroglycoconjugates -- potential antiproliferative agents.

The title compounds, variously protected 2.3-anhydrosugars linked with genistein through an alkyl chain, were synthesized in a sequence of reactions. First step involved Ferrier rearragement of 3,4-di-O-acetyl-L-rhamnal with 3-bromopropanol to obtain 2,3-unsaturated bromoalkylglycosides.

Aneugenic effects of the genistein glycosidic derivative substituted at C7 with the unsaturated disaccharide.

Genistein, due to its recognized chemopreventive and antitumour potential, is a molecule of interest as a lead compound in drug design. Recently, we found that the novel genistein derivative, [7-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-(1 → 4)-(6-O-acetyl-hex-2-ene-α-D-erythro pyranosyl)genistein, named G21, induced aberrations in mitotic spindle formation. In the presented study, we investigated the properties of G21 relevant to its genotoxic activity.

Identification of a new mouse sperm acrosome-associated protein.

The binding of capacitated spermatozoa to the egg's extracellular coat and induction of acrosome reaction are necessary for successful fertilization in mammals. Biogenesis of acrosome is complicated, and not all proteins involved in this process are known. In this study, we have cloned a novel mouse gene, Spaca7, that is expressed exclusively in the testes.

Melanoma-associated genes, MXI1, FN1, and NME1, are hypoxia responsive in murine and human melanoma cells.

Hypoxia can influence aggressiveness of melanoma by inducing specific gene expression profiles. In our previous microarray study, we identified more than 430 hypoxia-responsive genes in the B16-F10 murine melanoma cell line in vitro. Of the genes identified, seven genes: galectin 3 (Lgals3), melanoma cell adhesion molecule (Mcam), fibronectin 1 (Fn1), signal transducer and activator of transcription 3 (Stat3), microphthalmia-associated transcription factor (Mitf), max interacting protein 1 (Max1), and non-metastatic cells 1, protein (NM23A) expressed in (Nme1) are known to be associated with melanoma, but have not yet been reported as being regulated by hypoxia in human melanoma cells.

Synthetic conjugates of genistein affecting proliferation and mitosis of cancer cells.

This paper describes the synthesis and antiproliferative activity of conjugates of genistein (1) and unsaturated pyranosides. Constructs linking genistein with a sugar moiety through an alkyl chain were obtained in a two-step synthesis: in a first step genistein was converted into an intermediate bearing an ω-hydroxyalkyl substituent, containing two, three or five carbon atoms, at position 7, while the second step involved Ferrier glycosylation reaction, employing glycals. Antiproliferative activity of several genistein derivatives was tested in cancer cell lines in vitro.

Synthetic derivatives of genistein, their properties and possible applications.

Genistein, the principal isoflavone constituent of soybean, attracts much attention as a natural molecule with significant affinity towards targets of potential medicinal interest, but also as a food supplement or prospective chemopreventive agent. Since its physicochemical properties are considered suboptimal for drug development, much effort has been invested in designing its analogs and conjugates in hope to obtain compounds with improved efficacy and selectivity. The aim of this article is to summarize current knowledge about the properties of synthetic genistein derivatives and to discuss possible clinical application of selected novel compounds.

Synthesis and antiproliferative properties of ibuprofen-oligo(3-hydroxybutyrate) conjugates.

Synthesis of novel conjugates of the non-steroidal anti-inflammatory drug - ibuprofen with nontoxic oligo(3-hydroxybutyrate) (OHB) is described. Presented results indicate that anionic ring-opening polymerization of (R,S)-beta-butyrolactone initiated with an alkali metal salt of (S)-(+)-2-(4-isobutylphenyl)propionic acid (ibuprofen) may constitute a convenient method of conjugation of selected drugs with biodegradable OHB. Furthermore using the MTT cell proliferation assay we demonstrated that ibuprofen conjugated with OHB exhibited significantly increased, as compared to free ibuprofen, potential to inhibit proliferation of HT-29 and HCT 116 colon cancer cells.

Comparison of photodynamic efficacy of tetraarylporphyrin pegylated or encapsulated in liposomes: in vitro studies.

Two photosensitizing systems: (1) tetrakis(4-hydroxyphenyl)porphyrin (p-THPP) encapsulated in sterically stabilized liposomes (SSL) and (2) p-THPP functionalized by covalent attachment of poly(ethylene glycol) (p-THPP-PEG(2000)) were studied in vitro. The dark and photo cytotoxicity of these systems were evaluated on two cell lines: HCT 116, a human colorectal carcinoma cell line, and DU 145, a prostate cancer cell line and compared with these determined for free p-THPP. It was demonstrated that both encapsulation in liposomes as well as attachment of PEG chain result in pronounced reduction of the dark cytotoxicity of the parent porphyrin.

Unsaturated genistein disaccharide glycoside as a novel agent affecting microtubules.

Genistein, due to its recognized chemopreventive and antitumor potential, is a molecule of interest as a lead compound in drug design. While multiple molecular targets for genistein have been identified, so far neither for this isoflavonoid nor for its natural or synthetic derivatives disruption of microtubules and mitotic spindles has been reported. Here we describe such properties of the synthetic glycosidic derivative of genistein significantly more cytotoxic than genistein, 7-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-(1-->4)-(6-O-acetyl-hex-2-ene-alpha-D-erythro-pyranosyl)genistein, shortly named G21.

Oligo(3-hydroxybutanoate) conjugates with acetylsalicylic acid and their antitumour activity.

In this paper we discuss the anticancer activity of acetylsalicylic acid with oligo(3-hydroxybutanoate) conjugates, their characteristics and in vitro biological evaluation. Acetylsalicylic acid (aspirin) attached via hydrolysable ester bonds to non-toxic well-defined 3-hydroxybutanoic acid oligomers shows novel method of drug modification. The resulting conjugates were more effective than aspirin in growth inhibition of human colon adenocarcinoma cells HT-29 and human colon carcinoma cells HCT 116 in vitro.

Microfibril angle in wood of Scots pine trees (Pinus sylvestris) after irradiation from the Chernobyl nuclear reactor accident.

The secondary cell wall structure of tracheids of Scots pine (Pinus sylvestris L.), especially the angle of microfibrils in the S(2) layer, was examined in wood deposited prior to and after the Chernobyl accident in 1986. Microscopic analysis was carried out on wood samples collected in October 1997 from breast height of three pine trees 16, 30 and 42 years old.

Readjustments of cambial initials in Wisteria floribunda (Willd.) DC. for development of storeyed structure.

•  This study has elucidated the mechanism of development of the storeyed cambial structure of Wisteria floribunda, a species characterised by very quick and early establishment of storeyed structure from a nonstoreyed procambium in close vicinity of the pith. •  Rearrangement of the cambial cells was studied in serial tangential longitudinal sections of axial wood parenchyma. •  The mechanism of cell rearrangement was found to involve not only the occurrence of anticlinal cell divisions, but also a concomitant intrusive growth of the ends of cambial cells of one cell packet along the tangential walls of cells of the neighbouring packet.