Salidroside, a Chemopreventive Glycoside, Diminishes Cytotoxic Effect of Cisplatin in Vitro.

Natural products represent the source or the inspiration for the majority of the active ingredients of medicines because of their structural diversity and a wide range of biological effects. Our aims in this study were (i) to synthesize enzymatically salidroside (SAL), the most effective phenylethanoid glycoside in Rhodiola species; (ii) to examine its antioxidant capacity using cell-free assays (reducing power, DPPH radicals scavenging and Fe -chelating assays); (iii) to assess its DNA-protective potential on plasmid DNA (DNA topology assay) and in HepG2 cells (comet assay) damaged by Fe ions and hydrogen peroxide, respectively; and (iv) to investigate the effects of SAL, cisplatin (CDDP) and combined treatments of SAL + CDDP on cell viability (MTT test), level of DNA damage (comet assay), proliferation, cell cycle (flow cytometry) and the expression of signalling molecules associated with cell growth and apoptotic pathways (Western immunoblotting). We found out that SAL manifested low antioxidant and DNA-protective capacity in all assays used.

Modulation of cisplatin sensitivity in human ovarian carcinoma A2780 and SKOV3 cell lines by sulforaphane.

Cisplatin resistance is one of the major obstacles in the treatment of ovarian cancer. In an effort to look for new possibilities of how to overcome this difficulty, we studied the mechanisms of the interactions between sulforaphane (SFN) and cisplatin (cisPt) in combined treatment of human ovarian carcinoma A2780 and SKOV3 cell lines. Synergy (A2780) and antagonism (SKOV3) found in MTT assay was confirmed by apoptosis.

Realgar (As4S4) nanoparticles and arsenic trioxide (As2O3) induced autophagy and apoptosis in human melanoma cells in vitro.

The aim of the present study was to compare the effect of realgar nanoparticles and arsenic trioxide (ATO) on viability, DNA damage, proliferation, autophagy and apoptosis in the human melanoma cell lines BOWES and A375. The application of various flow cytometric methods for measurements cell viability, DNA cell cycle, mitochondrial potential, lysosomal activity, and intracellular content of glutathione was used. In addition, quantitative PCR, western blotting and multiplex bead array analyses were applied for evaluation of redox stress, autophagic flux, and cell signaling alterations.

Proteasome inhibition leads to altered signaling in the proteome of cisplatin-resistant human ovarian carcinoma cell line.

To address a precise view into molecular mechanisms of apoptotic signaling pathways after single- or combinatory treatments with specific NF-κB- or proteasome inhibitors and/or cisplatin (CDDP), flow cytometry and western blotting of the cell proteome in human ovarian chemosensitive- and CDDP-resistant cell lines were used. We report here that proteasome inhibition (but not NF-κB inhibition) caused marked alterations in the cell proliferation and cell cycle, as well as in the levels of signaling anti- and pro-apoptotic proteins PARP, NF-κB, IκB-α, Bcl-2, Bax, and lysosome-associated LAMP-1 and ATP-7B molecules in particular proteome fractions. These findings refer to the possibility of regulation of CDDP resistance, inclusive the capacity of lysosomes to export CDDP in certain human ovarian cancer cells by proteasome inhibition.

MGN-3 arabinoxylan rice bran modulates innate immunity in multiple myeloma patients.

Dendritic cells (DCs) and natural killer (NK) cells are central components of innate immunity for controlling tumor growth. The therapeutic effects of certain anti-myeloma drugs are partially mediated by targeting the innate immune response. In addition, novel types of natural compounds have been developed that efficiently modulate the activity of both the cellular and humoral compartments of immunity.

Modulation of markers associated with aggressive phenotype in MDA-MB-231 breast carcinoma cells by sulforaphane.

Metastasis as a complex process involves loss of adhesion, migration, invasion and proliferation of cancer cells. Sulforaphane (SFN) is one of naturally occurring cancer chemopreventive isothiocyanates found in cruciferous vegetables, consumption of which has been associated with reduced risk of cancer. In this study, we describe effect of SFN on various aspects determining invasive behavior of MDA-MB-231 human breast carcinoma cells.

Administration of isothiocyanate (E-4IB) and cisplatin leads to altered signalling and lysosomal export in human ovarian carcinoma sensitive- and cisplatin-resistant cells.

The aim of this study was to compare the effect of a new synthetic isothiocyanate derivative, ethyl 4-isothiocyanatobutanoate (E-4IB) and cisplatin (CDDP) in CDDP-sensitive human ovarian carcinoma cell line (A2780) and its resistant subline (A2780/CP). In parental cells, in comparison to untreated cells, sequential administration of both compounds led to higher exosomal dye (LysoTracker Green DND-26) retention and to alterations of mitogen-activated protein kinases (MAPKs), JNK, ERK and p38, or Akt kinase accompanied by changes in several anti- and pro-apoptotic molecules and lysosomal protein LAMP-1, as detected by Western blotting. On the contrary, variant A2780/CP cells were resistant to CDDP- or to combined sensitizer (E-4IB)/inducer (CDDP)-related apoptosis induction and exerted minor changes in the levels of these molecules.

Isothiocyanate E-4IB induces MAPK activation, delayed cell cycle transition and apoptosis.

Introduction: Epidemiologic studies point towards a significant correlation between the dietary intake of isothiocyanate-containing foods and the reduced risk for cancer.

Methods And Results: In the current investigation, we examined the consequence of activating of signalling pathways during the release the cells from the block at G(1)/S boundary by synthetic isothiocyanate E-4IB. Using synchronized leukaemic HL60 cells, we show that activation of mitogen-activated protein kinases ERK1/2, c-Jun N-terminal kinase and p38 signalling pathways by E-4IB are coupled with delayed transition through the cell cycle and rapid cell cycle arrest resulted in diminished mitochondrial membrane potential culminating in apoptosis.

Sensitisation for cisplatin-induced apoptosis by isothiocyanate E-4IB leads to signalling pathways alterations.

A new synthetic isothiocyanate (ITC) derivative, ethyl 4-isothiocyanatobutanoate (E-4IB), appeared to be an effective modulator of cellular proliferation and potent inducer of apoptosis. In cooperation with cisplatin, this compound exerted synergistic effects in human ovarian carcinoma A2780 cells. In the present study we investigated in more detail E4IB-sensitisation for cisplatin-induced apoptosis.

Diverse resveratrol sensitization to apoptosis induced by anticancer drugs in sensitive and resistant leukemia cells.

Naturally occurring dietary compound resveratrol (RES), possessing chemopreventive and cytostatic properties, has been shown as potent sensitizer for apoptosis induced by a variety of anticancer drugs. Cell cycle analysis in sensitive promyelocytic leukemia HL60 cell line and its multidrug-resistant variant HL60/VCR (P-gp positive) treated with RES resulted in cell cycle arrest in S-phase in both cell variants. Flow cytometry measurements showed diverse activities of RES in combination with anticancer drugs doxorubicin (DOX), cycloheximide (CHX), busulfan (BUS), gemcitabine (GEM) and paclitaxel (PTX), in some cases resulting in apoptosis induction, preferentially at the expense of S-phase.

Flavonoid quercetin, but not apigenin or luteolin, induced apoptosis in human myeloid leukemia cells and their resistant variants.

Flavonoids and their in vivo metabolites are neuroprotective, cardioprotective and chemopreventive agents acting as hydrogen-donating antioxidants or modulators functioning at protein kinase and lipid signaling pathways. In presented study treatments of human leukemia cells HL60 and their MDR-1 resistant subline HL60/VCR by flavonoids apigenin (API), luteolin (LUT), quercetin (QU) and anticancer drug doxorubicin (DOX) are reported. Of all flavonoids used only QU treatments led in both cell lines to DNA fragmentation, cleavage of poly (ADP- ribose) polymerase (PARP), up-regulation of proapoptotic Bax and posttranslational modification (phosphorylation) of antiapoptotic Bcl-2.

PSC 833 modulation of multidrug resistance to paclitaxel in cultured human ovarian carcinoma cells leads to apoptosis.

Background: Multidrug resistance (MDR) modulator PSC 833 has been shown to modulate multidrug resistance in Pg-p-positive human ovarian carcinoma cells A2780/ADR. Co-treatment of A2780/ADR cells with paclitaxel (PTX) and PSC 833 resulted in the restoration of PTX-sensitivity comparable to that in parental A2780 cells.

Results: The flow cytometry experiments presented here showed PTX-(A2780) and PTX plus PSC 833 (A2780/ADR)-induced cell accumulation in the G2/M-phase of the cell cycle with concomitant appearance of apoptotic cells with sub-G0 (hypodiploid) DNA content.

PK11195, an isoquinoline carboxamide ligand of the mitochondrial benzodiazepine receptor, increased drug uptake and facilitated drug-induced apoptosis in human multidrug-resistant leukemia cells in vitro.

The isoquinoline peripheral benzodiazepine receptor ligand PK11195 increased drug (daunomycin)- and fluorochrome (calcein-AM) uptake and induced apoptosis detected by flow cytometry (FCM) technique, DNA electrophoretic analysis and poly(ADP-ribose) polymerase (PARP) cleavage in human multidrug-resistant myeloid leukemia (BL-60/VCR) and ovarian carcinoma (A2780/ADR) cells in vitro. The position of PK11195 with respect to drug-resistance modulator (DRM) efficiency, compared to the reference DRMs with the aid of FCM technique, was as follows: PSC833 > verapamil > PK11195 > vincristine. Our data show up to now not indicated observation that PK11195 possesses multidrug resistance modulating activity.

PSC 833 induces apoptosis in drug-sensitive human leukemia cell line and modulates resistance to paclitaxel in its multidrug-resistant variant.

Background: The non-immunosuppressive cyclosporine analog PSC 833 has been shown to reverse multidrug-resistance of neoplastic cells including the MDR-1 gene coded P-glycoprotein (P-gp)-mediated cells resistant to paclitaxel.

Materials And Methods: Apoptosis was demonstrated in drug-sensitive HL-60 and multidrug-resistant human promyelocytic leukemia HL-60/ADR (MRP) and HL-60/VCR (MDR-1) cells in vitro with the aid of flow cytometry, DNA analysis and western blotting.

Results: The techniques used herein determined accumulation of paclitaxel/PSC 833 induced apoptotic cells with sub-G0 (hypodiploid) DNA content and blocked in the G2/M phase of the cell cycle, internucleosomal DNA fragmentation, poly (ADP-ribose) polymerase cleavage, Bcl-2 modulation and Bax up-regulation, without any significant alterations in the levels of Bcl-xL, CD95/Fas or Fas-L proteins.

Differential sensitivity of ovarian carcinoma cell lines to apoptosis induced by the IMPDH inhibitor benzamide riboside.

The differential sensitivity of examined human ovarian carcinoma cell lines (CH1, A-2780 and SKOV-3) to the IMPDH inhibitor, benzamide riboside (BR), was demonstrated with the aid of MTT assay. Present data show that all three examined ovarian carcinoma cell lines were sensitive to the cytotoxic effects of BR in the order of sensitivity CH1, SKOV-3, A-2780, (IC50 = 2.8, 4.

Radiation-induced apoptosis and cell cycle alterations in human carcinoma cell lines with different radiosensitivities.

Radiosensitivity of examined human neoplastic cell lines was assessed with the aid of MTT assay. Differences between radiosensitive and radioresistant human neoplastic cell lines were as follow: a) radiation-induced apoptosis detected by flow cytometry was apparent in the most radiosensitive (i.e.

Detection of apoptosis in a heterogenous cell population using flow cytometry.

Apoptosis induced in human leukemic cells (promyelocytic human leukemic cells HL-60, multidrug-resistant subline HL-60/VCR) and human ovarian carcinoma cells (A2780 and multidrug-resistant subline A2780/ADR) in vitro was detected by flow cytometric analysis or DNA electrophoresis. The cytofluorometric techniques utilized, i. e.

Angiogenesis inhibitor TNP-470: cytotoxic effects on human neoplastic cell lines.

Angiostatic substance TNP-470 displayed moderate cytotoxicity towards human leukemia HL-60, HL-60/ADR, HL-60/VCR and myeloma ARH77 cell lines with IC50 in the range 5-10 microM of concentrations and slightly higher IC50 for myeloma cell line U266. IC50 for ovarian CH-1, A2780 and A2780/ADR cell lines was in the range 10-15 microM with the exception of platinum-resistant SKOV3 cell line (more than 40 microM ). The IC50 values for MDA-MB-231 and MCF-7 breast carcinoma cell lines were 15 and 25 microM, respectively.

Cell surface immunophenotype and gelatinase activity of the human breast carcinoma cell line (MCF-7/6) with functionally defective E-cadherin.

Expression of differentiation and adhesion cell surface antigens (LewisX - CD15, CD44, syndecan 1 - CD138 and basigin/EMMPRIN - CD147) were determined on the cell surface of human breast carcinoma MCF7 cells in vitro with the aid of flow cytometry and compared with that of MCF-7/6 cells, with functionally defective E-cadherin system and increased biological aggressiveness. The major cell surface alterations in MCF-7/6 cells compared with the parental MCF-7 cell line were a markedly increased CD15 (LewisX) and CD44 antigen cell surface expression on MCF-7/6 cells. There were no major differences between parental MCF-7 and MCF-7/6 cells in cell surface syndecan 1, basigin/EMMPRIN, E-cadherin and high affinity non-integrin laminin receptor expression.

Pentoxifylline stimulates drug-induced apoptosis in leukemic cells.

Camptothecin (CAM) and cisplatin (cis-diamminedichloroplatinum(II), cis-Pt) were used as inducers of apoptosis in the mouse leukemic L1210 cells. Relatively high concentrations of 50 micromol cis-Pt and 50 micromol CAM, respectively, were used to induce the apoptotic DNA ladder. The simultaneous treatment of L1210 cells by the drug and pentoxifylline (PTX) resulted in a decrease of drug concentrations necessary for the induction of apoptosis.

Staurosporine enhanced benzamide riboside-induced apoptosis in human multidrug-resistant promyelocytic leukemia cells (HL-60/VCR) in vitro.

The inosine monophosphate (IMP) dehydrogenase inhibitor benzamide riboside (BR) induced apoptosis (detected with the aid of flow cytometric identification of cells with sub-G0 DNA content and increased side angle light scatter) equally or slightly more intensively in the multidrug-resistant human promyelocytic leukemia cell line (HL-60/VCR: MDR-1 gene, Pgp positive) in comparison with the parental drug sensitive HL-60 cells. Staurosporine alone induced relatively low level of apoptosis in parental HL-60 cells but higher level (approximately 35%) of apoptosis in multidrug-resistant HL-60/VCR cells after 24 hour induction. The combination of benzamide riboside and staurosporine induced in both drug-sensitive and drug-resistant HL-60 cells a marked proportion of apoptotic cells already after short (6 hour) induction (more than 30% of apoptotic cells).

Human multidrug-resistant (MRP,p190) myeloid leukemia HL-60/ADR cells in vitro: resistance to the mevalonate pathway inhibitor lovastatin.

Mevalonate pathway inhibitor lovastatin inhibited proliferation of human multidrug-resistant promyelocytic leukemia HL-60/ADR cells in vitro, with MRP-gene coded p190 mediated drug resistance, to a markedly lesser extent than that of the parental drug sensitive HL-60 cells and also that of the other human multidrug resistant (MDR-1, P-glycoprotein) myeloid leukemia cell line HL-60/VCR. The sensitivity of the examined human leukemia cell lines to the cytostatic activity of lovastatin correlated approximately with the potential of lovastatin to induce the characteristic cell cycle alteration (i.e.

The leukocyte common antigen (CD45) on human pre-B leukemia cells: variant glycoprotein form expression during the cell exposure to phorbol ester is blocked by a nonselective protein kinase inhibitor H7.

The human pre-B acute lymphoblastic leukemia cell line REH6 was utilized for characterization of CD45 glycoprotein by monoclonal antibodies (mAb) recognizing four distinct CD45 antigen specificities, i.e. nonrestricted CD45, restricted CD45RA, CD45RB and CD45R0.

Stimulation of 1-(beta-D-arabinofuranosyl)cytosine (AraC)-induced apoptosis in the multidrug resistant human promyelocytic leukemia cell lines with protein kinase inhibitors.

Stimulation of apoptosis induced by 1-(beta-D-arabinofuranosyl)cytosine (AraC) with protein kinase inhibitors (i.e. staurosporine, CGP 41251-a protein kinase C (PKC)-selective staurosporine derivative and protein tyrosine kinase (PKT) inhibitor genistein) was examined in two human multidrug-resistant promyelocytic leukemia (HL-60) cell lines with different cell membrane drug resistance-associated glycoproteins (i.

The protein kinase C inhibitor H7 blocks phosphorylation of stathmin during TPA-induced growth inhibition of human pre-B leukemia REH6 cells.

The human pre-B acute lymphoblastic leukemia cell line REH6 was used to analyze the regulation of a ubiquitous intracellular phosphoprotein stathmin (Mr 19,000, pl = 5.6-6.2).