Design, Synthesis and Biological Activities of Novel Gemini 20S-Hydroxyvitamin D3 Analogs

Vitamin D3 (D3) can be metabolized by cytochrome P450scc (CYP11A1) into 20S-hydroxyvitamin D3 (20D3) as a major metabolite. This bioactive metabolite has shown strong antiproliferative, antifibrotic, pro-differentiation and anti-inflammatory effects while being non-toxic (non-calcemic) at high concentrations. Since D3 analogs with two symmetric side chains (Gemini analogs) result in potent activation of the vitamin D receptor (VDR), we hypothesized that the chain length and composition of these types of analogs also containing a 20-hydroxyl group would affect their biological activities. In this study, we designed and synthesized a series of Gemini 20D3 analogs. Biological tests showed that some of these analogs are partial VDR activators and can significantly stimulate the expression of mRNA for VDR and VDR-regulated genes including CYP24A1 and transient receptor potential cation channel V6 (TRPV6). These analogs inhibited the proliferation of melanoma cells with potency comparable to that of 1α,25-dihydroxyvitamin D3. Moreover, these analogs reduced the level of interferon γ and up-regulated the expression of leukocyte associated immunoglobulin-like receptor 1 in splenocytes, indicating that they have potent anti-inflammatory activities. There are no clear correlations between the Gemini chain length and their VDR activation or biological activities, consistent with the high flexibility of the ligand-binding pocket of the VDR.

Effect of 5-azacytidine on miRNA expression in human breast cancer cells with different sensitivity to cytostatics

AIM

To analyze expression of miRNA in human breast cancer cells, sensitive and resistant to cisplatin and doxorubicin, and to explore possible modification of drug sensitivity via treatment of cells with 5-azacytidine (5-aza), a demethylating agent.

MATERIALS AND METHODS

The study was performed on wild-type MCF-7 cell line (MCF-7/S) and its two sublines MCF-7/Dox and MCF-7/DDP resistant to doxorubicin and cisplatin, respectively. Cells were treated with 5-aza, cisplatin, doxorubicin and their combinations. Relative expression levels of miRNA-221, -200b, -320a, -10b, -34a, -122 and -29b were examined, using qRT-PCR. The MTT assay was used to monitor cell viability.

RESULTS

We compared miRNA expression profiles in MCF-7/S and drug resistant MCF-7/Dox and MCF-7/DDP cells. Changes of miRNA-221, -200b, -320a, -10b, -34a, -122 and -29b were observed in both resistant cell lines. The most significant differences were found for miRNA-200b (decreased in 50.0 ± 2.6 and 63.0 ± 3.1 times for MCF-7/Dox and MCF-7/DDP cells, respectively) and for oncogenic miRNA-221 levels (increase in 62.0 ± 5.7 times for MCF-7/Dox and 83.8 ± 7.2 times for MCF-7/DDP cells). 5-aza treatment caused an increase of miRNA-10b, -122, -200b levels in MCF-7/S cells, miRNA-34a, -10b, -122, -200b and -320a levels in MCF-7/Dox cells and miRNA-34a, -10b, -200b and -320a levels in MCF-7/DDP cells. Pretreatment of all studied lines with 5-aza resulted in the increase of their sensitivity to studied cytostatics. In particular, the IC50 of doxorubicin decreased by 2-, 4- and 3-fold for cell lines MCF-7/S, MCF-7/Dox and MCF-7/DDP cells, respectively, and IC50 of cisplatin in studied cultures decreased by 3-, 2- and 1.5-fold, respectively.

CONCLUSIONS

It was shown that use of 5-aza can modify sensitivity of breast cancer cells to cytotoxic drugs not only by it's demetylation effect, but also by changes in expression of miRNAs, involved in cell proliferation, migration and drug resistance development.

Combined Treatment of MCF-7 Cells with AICAR and Methotrexate, Arrests Cell Cycle and Reverses Warburg Metabolism through AMP-Activated Protein Kinase (AMPK) and FOXO1

Cancer cells are characterized by metabolic alterations, namely, depressed mitochondrial oxidation, enhanced glycolysis and pentose phosphate shunt flux to support rapid cell growth, which is called the Warburg effect. In our study we assessed the metabolic consequences of a joint treatment of MCF-7 breast cancer cells with AICAR, an inducer of AMP-activated kinase (AMPK) jointly with methotrexate (MTX), a folate-analog antimetabolite that blunts de novo nucleotide synthesis. MCF7 cells, a model of breast cancer cells, were resistant to the individual application of AICAR or MTX, however combined treatment of AICAR and MTX reduced cell proliferation. Prolonged joint application of AICAR and MTX induced AMPK and consequently enhanced mitochondrial oxidation and reduced the rate of glycolysis. These metabolic changes suggest an anti-Warburg rearrangement of metabolism that led to the block of the G1/S and the G2/M transition slowing down cell cycle. The slowdown of cell proliferation was abolished when mitotropic transcription factors, PGC-1α, PGC-1β or FOXO1 were silenced. In human breast cancers higher expression of AMPKα and FOXO1 extended survival. AICAR and MTX exerts similar additive antiproliferative effect on other breast cancer cell lines, such as SKBR and 4T1 cells, too. Our data not only underline the importance of Warburg metabolism in breast cancer cells but nominate the AICAR+MTX combination as a potential cytostatic regime blunting Warburg metabolism. Furthermore, we suggest the targeting of AMPK and FOXO1 to combat breast cancer.

Investigation of the Antiproliferative Properties of Natural Sesquiterpenes from Artemisia asiatica and Onopordum acanthium on HL-60 Cells in Vitro

Plants and plant extracts play a crucial role in the research into novel antineoplastic agents. Four sesquiterpene lactones, artecanin (1), 3β-chloro-4α,10α-dihydroxy-1α,2α-epoxy-5α,7αH-guaia-11(13)-en-12,6α-olide (2), iso-seco-tanapartholide 3-O-methyl ether (3) and 4β,15-dihydro-3-dehydrozaluzanin C (4), were isolated from two traditionally used Asteraceae species (Onopordum acanthium and Artemisia asiatica). When tested for antiproliferative action on HL-60 leukemia cells, these compounds exhibited reasonable IC₅₀ values in the range 3.6–13.5 μM. Treatment with the tested compounds resulted in a cell cycle disturbance characterized by increases in the G1 and G2/M populations, while there was a decrease in the S phase. Additionally, 1–3 elicited increases in the hypodiploid (subG1) population. The compounds elicited concentration-dependent chromatin condensation and disruption of the membrane integrity, as revealed by Hoechst 33258–propidium staining. Treatment for 24 h resulted in significant increases in activity of caspases-3 and -9, indicating that the tested sesquiterpenes induced the mitochondrial pathway of apoptosis. The proapoptotic properties of the sesquiterpene lactones were additionally demonstrated withannexin V staining. Compounds 1 and 2 increased the Bax/Bcl-2 expression and decreased the expressions of CDK1 and cyclin B2, as determined at the mRNA level by means of RT-PCR. These experimental results indicate that sesquiterpene lactones may be regarded as potential starting structures for the development of novel anticancer agents.

Unusual Nitrogenous Phenalenone Derivatives from the Marine-Derived Fungus Coniothyrium cereale

The new phenalenone metabolites 1, 2, 4, and 6 were isolated from the marine-derived endophytic fungus Coniothyrium cereale, in addition to the ergostane-type sterol (3) and entatrovenetinone (5). Compounds 1 and 2 represent two unusual nitrogen-containing compounds, which are composed of a sterol portion condensed via two bonds to phenalenone derivatives. Compound 6, which contains unprecedented imine functionality between two carbonyl groups to form a oxepane -imine-dione ring, exhibited a moderate cytotoxicity against K562, U266, and SKM1 cancer cell lines. Moreover, molecular docking studies were done on estrogen receptor α-ligand binding domain (ERα-LBD) to compounds 1 and 2 to correlate with binding energies and affinities calculated from molecular docking to the anti-proliferative activity.

Higginsianins A and B, Two Diterpenoid α-Pyrones Produced by Colletotrichum higginsianum, with in Vitro Cytostatic Activity

Two new diterpenoid α-pyrones, named higginsianins A (1) and B (2), were isolated from the mycelium of the fungus Colletotrichum higginsianum grown in liquid culture. They were characterized as 3-[5a,9b-dimethyl-7-methylene-2-(2-methylpropenyl)dodecahydronaphtho[2,1-b]furan-6-ylmethyl]-4-hydroxy-5,6-dimethylpyran-2-one and 4-hydroxy-3-[6-hydroxy-5,8a-dimethyl-2-methylene-5-(4-methylpent-3-enyl)decahydronaphthalen-1-ylmethyl]-5,6-dimethylpyran-2-one, respectively, by using NMR, HRESIMS, and chemical methods. The structure and relative configuration of higginsianin A (1) were confirmed by X-ray diffractometric analysis, while its absolute configuration was assigned by electronic circular dichroism (ECD) experiments and calculations using a solid-state ECD/TDDFT method. The relative and absolute configuration of higginsianin B (2), which did not afford crystals suitable for X-ray analysis, were determined by NMR analysis and by ECD in comparison with higginsianin A. 1 and 2 were the C-8 epimers of subglutinol A and diterpenoid BR-050, respectively. The evaluation of 1 and 2 for antiproliferative activity against a panel of six cancer cell lines revealed that the IC50 values, obtained with cells reported to be sensitive to pro-apoptotic stimuli, are by more than 1 order of magnitude lower than their apoptosis-resistant counterparts (1 vs >80 μM). Finally, three hemisynthetic derivatives of 1 were prepared and evaluated for antiproliferative activity. Two of these possessed IC50 values and differential sensitivity profiles similar to those of 1.

[INFLUENCE OF ANGIOPROTECTOR DRUGS ON THE EFFICACY OF CYTOSTATIC THERAPY (EXPERIMENTAL STUDY)]

The influence of angioprotector and endothelium-protector drugs pentoxifylline and unifuzol as components of supportive therapy on the efficacy of combined cytostatic treatment has been experimentally studied. It is established that pentoxifylline and unifuzol do not affect the antitumor and antimetastatic activity of doxorubicin and cyclophosphan with respect to Pliss lymphosarcoma and Walker 256 carcinosarcoma, and in some cases even potentiate the effect of cytostatic therapy.

The Immunomodulatory Activity of Jacaric Acid, a Conjugated Linolenic Acid Isomer, on Murine Peritoneal Macrophages

This study aims at demonstrating the immunomodulatory property of jacaric acid, a conjugated linolenic acid (CLNA) isomer that is present in jacaranda seed oil, on murine peritoneal macrophages. Our results showed that jacaric acid exhibited no significant cytotoxicity on the thioglycollate-elicited murine peritoneal macrophages as revealed by the neutral red uptake assay, but markedly increased their cytostatic activity on the T-cell lymphoma MBL-2 cells as measured by the fluorometric CyQuant® NF Cell Proliferation Assay Kit. Flow cytometric analysis indicated that jacaric acid could enhance the endocytic activity of macrophages and elevated their intracellular production of superoxide anion. Moreover, jacaric acid-treated macrophages showed an increase in the production of nitric oxide which was accompanied by an increase in the expression level of inducible nitric oxide synthase protein. In addition, the secretion of several pro-inflammatory cytokines, including interferon-γ, interleukin-1β and tumor necrosis factor-α, was up-regulated. Collectively, our results indicated that the naturally-occurring CLNA isomer, jacaric acid, could exhibit immunomodulating activity on the murine peritoneal macrophages in vitro, suggesting that this CLNA isomer may act as an immunopotentiator which can be exploited for the treatment of some immunological disorders with minimal toxicity and fewer side effects.

Wittig derivatization of sesquiterpenoid polygodial leads to cytostatic agents with activity against drug resistant cancer cells and capable of pyrrolylation of primary amines

Many types of cancer, including glioma, melanoma, non-small cell lung cancer (NSCLC), among others, are resistant to proapoptotic stimuli and thus poorly responsive to current therapies based on the induction of apoptosis in cancer cells. The current investigation describes the synthesis and anticancer evaluation of unique C12-Wittig derivatives of polygodial, a sesquiterpenoid dialdehyde isolated from Persicaria hydropiper (L.) Delabre. These compounds were found to undergo an unprecedented pyrrole formation with primary amines in a chemical model system, a reaction that could be relevant in the biological environment and lead to the pyrrolation of lysine residues in the target proteins. The anticancer evaluation of these compounds revealed their promising activity against cancer cells displaying various forms of drug resistance, including resistance to proapoptotic agents. Mechanistic studies indicated that compared to the parent polygodial, which displays fixative general cytotoxic action against human cells, the C12-Wittig derivatives exerted their antiproliferative action mainly through cytostatic effects explaining their activity against apoptosis-resistant cancer cells. The possibility for an intriguing covalent modification of proteins through a novel pyrrole formation reaction, as well as useful activities against drug resistant cancer cells, make the described polygodial-derived chemical scaffold an interesting new chemotype warranting thorough investigation.

Bisleuconothine A Induces Autophagosome Formation by Interfering with AKT-mTOR Signaling Pathway

We have previously reported that bisleuconothine A (Bis-A), a novel bisindole alkaloid isolated from Leuconotis griffithii, showed cytostatic activity in several cell lines. In this report, the mechanism of Bis-A-induced cytostatic activity was investigated in detail using A549 cells. Bis-A did not cause apoptosis, as indicated by analysis of annexin V and propidium iodide staining. Expression of all tested apoptosis-related proteins was also unaffected by Bis-A treatment. Bis-A was found to increase LC3 lipidation in MCF7 cells as well as A549 cells, suggesting that Bis-A cytostatic activity may be due to induction of autophagy. Subsequent investigation via Western blotting and immunofluorescence staining indicated that Bis-A induced formation but prevented degradation of autophagosomes. Mechanistic studies showed that Bis-A down-regulated phosphorylation of protein kinase B (AKT) and its downstream kinase, PRAS40, which is an mTOR repressor. Moreover, phosphorylation of p70S6K, an mTOR-dependent kinase, was also down-regulated. Down-regulation of these kinases suggests that the increase in LC3 lipidation may be due to mTOR deactivation. Thus, the cytostatic activity shown by Bis-A may be attributed to its induction of autophagosome formation. The Bis-A-induced autophagosome formation was suggested to be caused by its interference with the AKT-mTOR signaling pathway.

[Antitumor action and other regulatory effects of low intensity electromagnetic and chemical factors in experiment]

This paper presents a brief overview of the results of the original researches of biological responses induced by agents of cytostatic and regulatory actions in small doses, as well as weak electromagnetic radiation of different frequency bands. The possibility of obtaining the expressed antitumor, antistress and geroprotective effects has been shown. The question of the relation of system mechanisms of realization of these effects with structural rearrangements in biological fluids, as well as the promising directions for optimizing the therapeutic properties of the informational impacts are discussed.

Hepatoprotective saikosaponin homologs from Comastoma pedunculatum

Eight new triterpenoid saponins, the saikosaponin homologs comastomasaponins A-H (1-8), as well as a known triterpenoid (9) and eight known saponins (10-17) were isolated from the aerial portions of Comastoma pedunculatum. The structures of these compounds were elucidated spectroscopically, and their hepatoprotective activity and cytotoxic activity were evaluated against five human tumor cell lines in vitro. Compounds 1, 5-12, 14, 15, and 17 exhibited potent hepatoprotective activity, and compound 11 displayed cytotoxic activity against HCT-8, Bel-7402, BGC-825, A549, and A2780 human tumor cell lines.

Evaluation of the toxicity of 5-aryl-2-aminoimidazole-based biofilm inhibitors against eukaryotic cell lines, bone cells and the nematode Caenorhabditis elegans

Previously, we have synthesized several series of compounds based on the 5-aryl-2-aminoimidazole scaffold, which showed a preventive activity against microbial biofilms. We here studied the cytotoxicity of the most active compounds of each series. First, the cytostatic activity was investigated against a number of tumor cell lines (L1210, CEM and HeLa). A subset of monosubstituted 5-aryl-2-aminoimidazoles showed a moderate safety window, with therapeutic indices (TIs) ranging between 3 and 20. Whereas introduction of a (cyclo-)alkyl chain at the N1-position strongly reduced the TI, introduction of a (cyclo-)alkyl chain or a triazole moiety at the 2N-position increased the TI up to 370. Since a promising application of preventive anti-biofilm agents is their use in anti-biofilm coatings for orthopedic implants, their effects on cell viability and functional behavior of human osteoblasts and bone marrow derived mesenchymal stem cells were tested. The 2N-substituted 5-aryl-2-aminoimidazoles consistently showed the lowest toxicity and allowed survival of the bone cells for up to 4 weeks. Moreover they did not negatively affect the osteogenic differentiation potential of the bone cells. Finally, we examined the effect of the compounds on the survival of Caenorhabditis elegans, which confirmed the higher safety window of 2N-substituted 5-aryl-2-aminoimidazoles.

Isolation and cytotoxic effect of anthraquinones from Morinda umbellata

Four new anthraquinones, 1,6-dihydroxy-2-methoxymethylanthraquinone (1), 6-hydroxy-7-methoxy-2-methoxymethylanthraquinone (3), 3,6-dihydroxy-7-methoxy-2-methylanthraquinone (4), and 6-hydroxy-2-methoxymethylanthraquinone (8), together with 12 known anthraquinones and 6 other known compounds, were isolated from the EtOAc extract of Morinda umbellata. Among the isolated compounds, 1, rubiadin (14), and, 3-hydroxy-2-hydroxymethylanthraquinone (16) exhibited significant cytotoxicities against HepG2 cells, with GI50 values of 4.4, 3.6, and 4.8 µM, respectively.

Design, synthesis, antiviral and cytostatic activity of ω-(1H-1,2,3-triazol-1-yl)(polyhydroxy)alkylphosphonates as acyclic nucleotide analogues

The efficient synthesis of a new series of polyhydroxylated dibenzyl ω-(1H-1,2,3-triazol-1-yl)alkylphosphonates as acyclic nucleotide analogues is described starting from dibenzyl ω-azido(polyhydroxy)alkylphosphonates and selected alkynes under microwave irradiation. Selected O,O-dibenzylphosphonate acyclonucleotides were transformed into the respective phosphonic acids. All compounds were evaluated in vitro for activity against a broad variety of DNA and RNA viruses and for cytostatic activity against murine leukemia L1210, human T-lymphocyte CEM and human cervix carcinoma HeLa cells. Compound (1S,2S)-16b exhibited antiviral activity against Influenza A H3N2 subtype (EC50=20μM-visual CPE score; EC50=18μM-MTS method; MCC >100μM, CC50 >100μM) in Madin Darby canine kidney cell cultures (MDCK), and (1S,2S)-16k was active against vesicular stomatitis virus and respiratory syncytial virus in HeLa cells (EC50=9 and 12μM, respectively). Moreover, compound (1R,2S)-16l showed activity against both herpes simplex viruses (HSV-1, HSV-2) in HEL cell cultures (EC50=2.9 and 4μM, respectively) and feline herpes virus in CRFK cells (EC50=4μM) but at the same time it exhibited cytotoxicity toward uninfected cell (MCC⩾4μM). Several other compounds have been found to inhibit proliferation of L1210, CEM as well as HeLa cells with IC50 in the 4-50μM range. Among them compounds (1S,2S)- and (1R,2S)-16l were the most active (IC50 in the 4-7μM range).

Signaling mechanisms that suppress the cytostatic actions of rapamycin

While rapamycin and the "rapalogs" Everolimus and Temsirolimus have been approved for clinical use in the treatment of a number of forms of cancer, they have not met overarching success. Some tumors are largely refractory to rapamycin treatment, with some even undergoing an increase in growth rates. However the mechanisms by which this occurs are largely unknown. The results presented here reveal novel cell-signaling mechanisms that may lead to this resistance. The absence of TGFβ signaling results in resistance to rapamycin. Additionally, we observed that treatment of some cancer cell lines with rapamycin and its analogs not only potentiates mitogenic signaling and proliferation induced by HGF, but also stimulates the pro-survival kinase Akt. Together, the data show that the effectiveness of rapamycin treatment can be influenced by a number of factors and bring to light potential biomarkers for the prediction of responsiveness to treatment, and suggest combination therapies to optimize rapalog anticancer efficacy.

Interaction of standardized mistletoe (Viscum album) extracts with chemotherapeutic drugs regarding cytostatic and cytotoxic effects in vitro

BACKGROUND

Given the importance of complementary and alternative medicine (CAM) to cancer patients, there is an increasing need to learn more about possible interactions between CAM and anticancer drugs. Mistletoe (Viscum album L.) belongs to the medicinal herbs that are used as supportive care during chemotherapy. In the in vitro study presented here the effect of standardized mistletoe preparations on the cytostatic and cytotoxic activity of several common conventional chemotherapeutic drugs was investigated using different cancer cell lines.

METHODS

Human breast carcinoma cell lines HCC1937 and HCC1143 were treated with doxorubicin hydrochloride, pancreas adenocarcinoma cell line PA-TU-8902 with gemcitabine hydrochloride, prostate carcinoma cell line DU145 with docetaxel and mitoxantrone hydrochloride and lung carcinoma cell line NCI-H460 was treated with docetaxel and cisplatin. Each dose of the respective chemotherapeutic drug was combined with Viscum album extract (VAE) in clinically relevant concentrations and proliferation and apoptosis were measured.

RESULTS

VAE did not inhibit chemotherapy induced cytostasis and cytotoxicity in any of our experimental settings. At higher concentrations VAE showed an additive inhibitory effect.

CONCLUSIONS

Our in vitro results suggest that no risk of safety by herb drug interactions has to be expected from the exposition of cancer cells to chemotherapeutic drugs and VAE simultaneously.

[Antitumor and antiproliferative action of the steroidal cytostatic antiestrogen cytestrol acetate on hormone-dependent tumor models]

Cytestrole acetate (CA), in the structure of which the steroidal antiestrogen component is associated with bis-β-cloroethylamino group, exhibits a strong cytotoxic activity against hormone-dependent cancer cell lines (CaOV, HeLa, MCF-7). In doxorubicin-resistant MCF-7 cells, CA potentiates the cytotoxic effect of etoposide and doxorubicin, and the IC50 for CA in these cells is 40 times lower than that for tamoxifen (TAM). In transplantable mice breast adenocarcinoma Ca-755, the therapeutic CA dose is 25 mg/kg when administered subcutaneously in oil solution for 5 days. On the DMBA-induced mammary tumors in rats, CA injected subcutaneously led to partial regressions 4 weeks after treatment in 75% of test rats, whereas TAM produced this effect in 43% of rats. Among various drug forms of CA, the most active were oil solution of CA in gelatin capsules for oral use and liposomal emulsion for intravenous administration, since these forms exhibited the highest values of Ca-755 tumor growth inhibition index (TGI = 97 - 98%).

Cytotoxic, cytostatic and HIV-1 PR inhibitory activities of the soft coral Litophyton arboreum

Bioassay-guided fractionation using different chromatographic and spectroscopic techniques in the analysis of the Red Sea soft coral Litophyton arboreum led to the isolation of nine compounds; sarcophytol M (1), alismol (2), 24-methylcholesta-5,24(28)-diene-3β-ol (3), 10-O-methyl alismoxide (4), alismoxide (5), (S)-chimyl alcohol (6), 7β-acetoxy-24-methylcholesta-5-24(28)-diene-3,19-diol (7), erythro-N-dodecanoyl-docosasphinga-(4E,8E)-dienine (8), and 24-methylcholesta-5,24(28)-diene-3β,7β,19-triol (9). Some of the isolated compounds demonstrated potent cytotoxic- and/or cytostatic activity against HeLa and U937 cancer cell lines and inhibitory activity against HIV-1 protease (PR). Compound 7 was strongly cytotoxic against HeLa cells (CC₅₀ 4.3 ± 0.75 µM), with selectivity index of SI 8.1, which was confirmed by real time cell electronic sensing (RT-CES). Compounds 2, 7, and 8 showed strong inhibitory activity against HIV-1 PR at IC₅₀s of 7.20 ± 0.7, 4.85 ± 0.18, and 4.80 ± 0.92 µM respectively. In silico docking of most compounds presented comparable scores to that of acetyl pepstatin, a known HIV-1 PR inhibitor. Interestingly, compound 8 showed potent HIV-1 PR inhibitory activity in the absence of cytotoxicity against the cell lines used. In addition, compounds 2 and 5 demonstrated cytostatic action in HeLa cells, revealing potential use in virostatic cocktails. Taken together, data presented here suggest Litophyton arboreum to contain promising compounds for further investigation against the diseases mentioned.

Growth inhibition of hepatocellular carcinoma Huh7 cells by Lactobacillus casei extract

PURPOSE

Lactobacillus casei (L. casei) is known to exert anti-proliferation effects on many types of cancer cells. However, the effect of L. casei on liver cancer has not been reported. Accordingly, the aim of this study was to determine the anti-cancer effect of L. casei extract on Huh7 cells.

MATERIALS AND METHODS

L. casei ATCC393 extract was prepared and purified. After the treatment of L. casei extract on Huh7 cells, cell viability, cell cycle arrest and cell death were analyzed by flow cytometry. The expression levels of tumor necrosis factor-α receptor 1 (TNFR1) and death receptor 3 (DR3) mRNA related with extrinsic apoptosis were assessed by reverse transcription polymerase chain reaction. Additionally, P21 and P27 cell cycle proteins as well as Caspase-3, -8, -9, phospho-Bad and Bcl-2 apoptosis proteins were analyzed by western blot analysis. To determine the effect of L. casei extract on cancer stem-like cells, we analyzed changes in side population fraction through flow cytometry.

RESULTS

The cell viability of Huh7 cells treated with L. casei extract was decreased by 77%, potentially owing to increases in the rates of Huh7 cells arrested in the G2/M phase (3% increase) and that underwent apoptosis (6% increase). The expression levels of TNFR1 and DR3 mRNA, as well as P21 and P27 cell cycle proteins, were increased. Meanwhile, the expressions of caspase-8, -9, phospho-Bad and Bcl-2 proteins decreased. However, in the case of side population cells, no remarkable changes were observed.

CONCLUSION

L. casei extract exerts a potent anti-tumor effect on the viability of liver cancer cells, although not on cancer stem-like cells.

[Identification of the functional activity of synthetic polyamine analogues using a biotest system based on highly proliferating cultured human cells]

A new biotest system was developed based on highly proliferating human cell cultures (lines LNCaP and PC-3). With the help of this system, two known synthetic polyamines--alpha-difluoromethylornithine (DFMO) and methylglioxalbis(guanylhydrason) (MGBG)--as well as four new synthetic analogues difenyl containing amines (DFCA-1-DFCA-4) with molecular weights of 725.5 (DFCA-1), 755.5 (DFCA-2), 655.5 (DFCA-3), and 681.5 Da (DFCA-4) were tested. In this biotest system, DFMO (0.1-400 microM) did not reveal functional activity, whereas for MGBG a cytotoxic effect was registered (100-200 microM). DFCA-1, DFCA-2, and DFCA-4 had a similar effect at concentrations of 10 microM and higher; DFCA-3, at a concentration of 50 microM and higher. Thus, DFCA-1 has a higher level of antiproliferating activity and may be considered as the most potent cytostatic agent.

NCI-RTOG translational program strategic guidelines for the early-stage development of radiosensitizers

The addition of chemotherapeutic agents to ionizing radiation has improved survival in many malignancies. Cure rates may be further improved by adding novel targeted agents to current radiotherapy or radiochemotherapy regimens. Despite promising laboratory data, progress in the clinical development of new drugs with radiation has been limited. To define and address the problems involved, a collaborative effort between individuals within the translational research program of the Radiation Oncology Therapy Group and the National Cancer Institute was established. We discerned challenges to drug development with radiation including: 1) the limited relevance of preclinical work, 2) the pharmaceutical industry's diminished interest, and 3) the important individual skills and institutional commitments required to ensure a successful program. The differences between early-phase trial designs with and without radiation are noted as substantial. The traditional endpoints for early-phase clinical trials-acute toxicity and maximum-tolerated dose-are of limited value when combining targeted agents with radiation. Furthermore, response rate is not a useful surrogate marker of activity in radiation combination trials.Consequently, a risk-stratified model for drug-dose escalation with radiation is proposed, based upon the known and estimated adverse effects. The guidelines discuss new clinical trial designs, such as the time-to-event continual reassessment method design for phase I trials, randomized phase II "screening" trials, and the use of surrogate endpoints, such as pathological response. It is hoped that by providing a clear pathway, this article will accelerate the rate of drug development with radiation.

New prognostic factors in breast cancer

For many years, the age of the patient, the condition of axillar lymph nodes, the size of the tumour, histological traits (in particular histological grade of malignancy and invasion of lymphatic vessels), condition of hormonal receptors and HER2 represented principal factors used for the stratification of breast cancer patients for the purposes of evaluating the prognosis and determining the appropriate strategy of treatment. Although the variables are useful for the prognostic evaluation of individual groups of breast cancer patients, their role in determining the individual risk level of the patient and in the selection of supplementary treatment is quite restricted. This article shows the prognostic value of additional parameters, whose expression is associated with chemioresistance (MRP2, BCRP, YB1) or individual assessment of the dynamics of tumor progression (S100P, BUBR1). In addition, it describes the role of an online database of "The Kaplan-Meier plotter" which contains the assessment of the effects of expression of various genes on the clinical outcome of patients with breast cancer.

Secondary metabolites from a culture of the fungus Neosartorya pseudofischeri and their in vitro cytostatic activity in human cancer cells

Four known (1, 2, 3, and 6) and three new compounds including a 1,4-diacetyl-2,5-dibenzylpiperazine derivative (4), a quinazolinone-containing indole derivative (5), and a new ester of 2,4-dihydroxy-6-methylbenzoic acid (7) were isolated from the fungus Neosartorya pseudofischeri S. W. Peterson. Compound 2 displayed in vitro growth inhibitory activity that ranged between the activities of etoposide and carboplatin, chosen as reference compounds, in six distinct cancer cell lines. Compound 1 displayed less activity than 2. Computer-assisted phase-contrast microscopy-related analysis revealed that 2 displayed cytostatic, not cytotoxic, effects in human U373 glioblastoma and A549 non-small cell lung cancer apoptosis-resistant cells with marked inhibition of mitotic rates. Cancer cells in the remaining phases of the cell cycle were unchanged. Flow cytometry analysis further confirmed that 2 does not induce apoptotic features in U373 or A549 cancer cells. Thus, 2 represents a novel chemical scaffold from which derivatives for anticancer cytostatic compounds can be derived.

Cytostatic activity of a 5-fluoro-2'-deoxyuridine-alendronate conjugate against gastric adenocarcinoma and non-malignant intestinal and fibroblast cell lines

BACKGROUND

5-Fluoro-2'-deoxyuridine (5-FdU), a drug against gastric cancer, was covalently linked via its nucleobase with the amino-bisphosphonate alendronate (Ale), resulting in a new antimetabolite-bisphosphonate conjugate (5-FdU-Ale), designed for bone-targeting.

MATERIALS AND METHODS

The cytostatic effect of 5-FdU-Ale was evaluated in vitro compared to monomers and mixtures using CASY Technologies and the human gastric adenocarcinoma cell lines 23132/87 and MKN-45, in comparison to the intestinal CCL-241 and dermal fibroblast NHDF neonatal cell lines.

RESULTS

The adenocarcinoma cell lines demonstrated a slightly higher sensitivity, with respect to the cell lines CCL-241 and NHDF, to incubation with 5-FdU-Ale. In comparison to 5-FdU, 5-FU and an equimolar mixture of Ale+5-FdU and Ale+5-FU, the cytostatic activity of the 5-FdU-Ale was markedly reduced.

CONCLUSION

5-FdU-Ale was only partially or not at all metabolized to a mixture of cytostatic metabolites in vitro. Therefore an in vivo evaluation of the conjugates is indicated.