Macrolide antibiotics enhance the antitumor effect of lansoprazole resulting in lysosomal membrane permeabilization­associated cell death.

The proton pump inhibitor lansoprazole (LPZ) inhibits the growth of several cancer cell lines, including A549 and CAL 27. We previously reported that macrolide antibiotics such as azithromycin (AZM) and clarithromycin (CAM) potently inhibit autophagic flux and that combining AZM or CAM with the epidermal growth factor receptor inhibitors enhanced their antitumor effect against various cancer cells. In the present study, we conducted the combination treatment with LPZ and macrolide antibiotics against A549 and CAL 27 cells and evaluated cytotoxicity and morphological changes using cell proliferation and viability assays, flow cytometric analysis, immunoblotting, and morphological assessment. Combination therapy with LPZ and AZM greatly enhanced LPZ­induced cell death, whereas treatment with AZM alone exhibited negligible cytotoxicity. The observed cytotoxic effect was not mediated through apoptosis or necroptosis. Transmission electron microscopy of A549 cells treated with the LPZ + AZM combination revealed morphological changes associated with necrosis and accumulated autolysosomes with undigested contents. Furthermore, the A549 cell line with ATG5 knockout exhibited complete inhibition of autophagosome formation, which did not affect LPZ + AZM treatment­induced cytotoxicity, thus excluding the involvement of autophagy­dependent cell death in LPZ + AZM treatment­induced cell death. A549 cells treated with LPZ + AZM combination therapy retained the endosomal Alexa­dextran for extended duration as compared to untreated control cells, thus indicating impairment of lysosomal digestion. Notably, lysosomal galectin­3 puncta expression induced due to lysosomal membrane permeabilization was increased in cells treated with LPZ + AZM combination as compared to the treatment by either agent alone. Collectively, the present results revealed AZM­induced autolysosome accumulation, potentiated LPZ­mediated necrosis, and lysosomal membrane permeabilization, thus suggesting the potential clinical application of LPZ + AZM combination therapy for cancer treatment.

Fundamental study of sterilization effects on marine Vibrio sp. in a cylindrical water chamber with supply of only underwater shock waves.

The effect of shock sterilization on marine Vibrio sp. is investigated by carrying out a bio-experiment based on a bubble-shockwave interaction. In the experiments, underwater shock waves with different strength and frequencies are produced by a high-voltage power supply in a cylindrical water chamber. The bio-experimental results show marine Vibrio sp. is completely inactivated in a short time by a 1.0-Hz electric discharge. However, a high sterilization effect requires a strong and high frequency of the bubble motion, and it also depends on the lifetime of the bubble. Subsequently, by an experiment with an air gap to prevent the underwater shock waves entering the cell suspension, it is found that the introduction of a strong shock pressure is not entirely required to obtain the effective sterilization. On the other hand, the direct effect of the sterilization by rebound shock wave resulting from the bubble-shock wave interaction is examined in the experiments. The results suggest that free radicals mainly contribute to killing marine bacteria, and direct mechanical effects of the bubble motion are not responsible. In addition, the creation of the OH radical is indirectly confirmed by measuring the H2O2 concentration. Finally, the Herring equation is solved to investigate the condition of free radical generation when considering the effect of thermal conductivity at the bubble interface. As a result, the effective sterilization conditions based on the bubble-shock wave interaction are clearly obtained.

Macrolide Antibiotics Exhibit Cytotoxic Effect under Amino Acid-Depleted Culture Condition by Blocking Autophagy Flux in Head and Neck Squamous Cell Carcinoma Cell Lines.

Autophagy, a self-digestive system for cytoplasmic components, is required to maintain the amino acid pool for cellular homeostasis. We previously reported that the macrolide antibiotics azithromycin (AZM) and clarithromycin (CAM) have an inhibitory effect on autophagy flux, and they potently enhance the cytocidal effect of various anticancer reagents in vitro. This suggests that macrolide antibiotics can be used as an adjuvant for cancer chemotherapy. Since cancer cells require a larger metabolic demand than normal cells because of their exuberant growth, upregulated autophagy in tumor cells has now become the target for cancer therapy. In the present study, we examined whether macrolides exhibit cytotoxic effect under an amino acid-starving condition in head and neck squamous cancer cell lines such as CAL 27 and Detroit 562 as models of solid tumors with an upregulated autophagy in the central region owing to hypovascularity. AZM and CAM induced cell death under the amino acid-depleted (AAD) culture condition in these cell lines along with CHOP upregulation, although they showed no cytotoxicity under the complete culture medium. CHOP knockdown by siRNA in the CAL 27 cells significantly suppressed macrolide-induced cell death under the AAD culture condition. CHOP-/- murine embryonic fibroblast (MEF) cell lines also attenuated AZM-induced cell death compared with CHOP+/+ MEF cell lines. Using a tet-off atg5 MEF cell line, knockout of atg5, an essential gene for autophagy, also induced cell death and CHOP in the AAD culture medium but not in the complete culture medium. This suggest that macrolide-induced cell death via CHOP induction is dependent on autophagy inhibition. The cytotoxicity of macrolide with CHOP induction was completely cancelled by the addition of amino acids in the culture medium, indicating that the cytotoxicity is due to the insufficient amino acid pool. These data suggest the possibility of using macrolides for "tumor-starving therapy".

Targeting bortezomib-induced aggresome formation using vinorelbine enhances the cytotoxic effect along with ER stress loading in breast cancer cell lines.

The ubiquitin-proteasome and autophagy-lysosome pathways are two major self-digestive systems for cellular proteins. Ubiquitinated misfolded proteins are degraded mostly by proteasome. However, when ubiquitinated proteins accumulate beyond the capacity of proteasome clearance, they are transported to the microtubule-organizing center (MTOC) along the microtubules to form aggresomes, and subsequently some of them are degraded by the autophagy-lysosome system. We previously reported that macrolide antibiotics such as azithromycin and clarithromycin block autophagy flux, and that concomitant treatment with the proteasome inhibitor bortezomib (BZ) and macrolide enhances endoplasmic reticulum (ER) stress-mediated apoptosis in breast cancer cells. As ubiquitinated proteins are concentrated at the aggresome upon proteasome failure, we focused on the microtubule as the scaffold of this transport pathway for aggresome formation. Treatment of metastatic breast cancer cell lines (e.g., MDA-MB­231 cells) with BZ resulted in induction of aggresomes, which immunocytochemistry detected as a distinctive eyeball-shaped vimentin-positive inclusion body that formed in a perinuclear lesion, and that electron microscopy detected as a sphere of fibrous structure with some dense amorphous deposit. Vinorelbine (VNR), which inhibits microtubule polymerization, more effectively suppressed BZ-induced aggresome formation than paclitaxel (PTX), which stabilizes microtubules. Combined treatment using BZ and VNR, but not PTX, enhanced the cytotoxic effect and apoptosis induction along with pronounced ER stress loading such as upregulation of GRP78 and CHOP/GADD153. The addition of azithromycin to block autophagy flux in the BZ plus VNR-containing cell culture further enhanced the cytotoxicity. These data suggest that suppression of BZ-induced aggresome formation using an inhibitory drug such as VNR for microtubule polymerization is a novel strategy for metastatic breast cancer therapy.

2-Aminophenoxazine-3-one-induced apoptosis via generation of reactive oxygen species followed by c-jun N-terminal kinase activation in the human glioblastoma cell line LN229.

2-Aminophenoxazine-3-one (Phx-3) induces apoptosis in several types of cancer cell lines. However, the mechanism of apoptosis induction by Phx-3 has not been fully elucidated. In this study, we investigated the anticancer effects of Phx-3 in the glioblastoma cell line LN229 and analyzed its molecular mechanism. The results indicated that 6- and 20-h treatment with Phx-3 significantly induced apoptosis in LN229 cells, with downregulation of survivin and XIAP. Both ERK and JNK, which are the members of the MAPK family, were activated after treatment with Phx-3. Inhibition of ERK using the specific inhibitor U0126 blocked the Phx-3-induced apoptosis only in part. However, inhibition of JNK using the specific inhibitor SP600125 completely prevented Phx-3-induced apoptosis and restored the phosphorylation states of ERK to the control levels. Enhanced generation of reactive oxygen species (ROS) was detected after 3-h treatment with Phx-3. In addition, the ROS scavenger melatonin almost completely blocked Phx-3-induced JNK activation and apoptosis. This suggests that JNK activation was mediated by Phx-3-induced ROS generation. Although SP600125 and melatonin completely blocked the reduction of mitochondrial membrane potential after a 3-h treatment with Phx-3, extension of Phx-3 exposure time to 20 h resulted in no cancelation of mitochondrial depolarization by these reagents. These reagents also had little effect on the decreased expression of survivin and XIAP during a 3-20-h exposure to Phx-3. These results indicate that the production of ROS following JNK activation is the main axis of Phx-3-induced apoptosis in LN229 cells for short-term exposure to Phx-3, whereas alternative mechanism(s) appear to be involved in apoptosis induction during long-term exposure to Phx-3.

Macrolide antibiotics block autophagy flux and sensitize to bortezomib via endoplasmic reticulum stress-mediated CHOP induction in myeloma cells.

The specific 26S proteasome inhibitor bortezomib (BZ) potently induces autophagy, endoplasmic reticulum (ER) stress and apoptosis in multiple myeloma (MM) cell lines (U266, IM-9 and RPMI8226). The macrolide antibiotics including concanamycin A, erythromycin (EM), clarithromycin (CAM) and azithromycin (AZM) all blocked autophagy flux, as assessed by intracellular accumulation of LC3B-II and p62. Combined treatment of BZ and CAM or AZM enhanced cytotoxicity in MM cell lines, although treatment with either CAM or AZM alone exhibited almost no cytotoxicity. This combination also substantially enhanced aggresome formation, intracellular ubiquitinated proteins and induced the proapoptotic transcription factor CHOP (CADD153). Expression levels of the proapoptotic genes transcriptionally regulated by CHOP (BIM, BAX, DR5 and TRB3) were all enhanced by combined treatment with BZ plus CAM, compared with treatment with each reagent alone. Like the MM cell lines, the CHOP+/+ murine embryonic fibroblast (MEF) cell line exhibited enhanced cytotoxicity and upregulation of CHOP and its transcriptional targets with a combination of BZ and one of the macrolides. In contrast, CHOP-/- MEF cells exhibited resistance against BZ and almost completely canceled enhanced cytotoxicity with a combination of BZ and a macrolide. These data suggest that ER stress-mediated CHOP induction is involved in pronounced cytotoxicity. Simultaneously targeting two major intracellular protein degradation systems such as the ubiquitin-proteasome system by BZ and the autophagy-lysosome system by a macrolide antibiotic enhances ER stress-mediated apoptosis in MM cells. This result suggests the therapeutic possibility of using a macrolide antibiotic with a proteasome inhibitor for MM therapy.

Harmol induces autophagy and subsequent apoptosis in U251MG human glioma cells through the downregulation of survivin.

The ß-carboline alkaloids are plant substances that exhibit a wide spectrum of neuropharmacological, psychopharma-cological and antitumor effects. In the present study, we found that harmol, a ß-carboline alkaloid, induced autophagy and suppression of survivin expression, and subsequently induced apoptotic cell death in U251MG human glioma cells. Autophagy was induced within 12 h by treatment with harmol. When treated for over 36 h, however, apoptotic cell death was induced. Harmol treatment also reduced survivin protein expression. Small interfering RNA (siRNA)-mediated knockdown of survivin enhanced the harmol-induced apoptosis. Knockdown of survivin by siRNA also induced autophagy. Therefore, harmol-induced apoptosis is a result of the reduction in survivin protein expression. Treatment with 3-methyladenine (3-MA) in the presence of harmol did not affect the expression of survivin and diminished harmol-induced cell death. Treatment with chloroquine in the presence of harmol did not suppress the reduction of survivin expression and increased harmol-induced cell death. From these results, harmol-induced reduction of survivin expression was closely related to autophagy. It is assumed that when isolation membrane formation is inhibited by treatment with 3-MA, reduction of survivin protein expression and apoptotic cell death were not induced. However, when isolation membrane formation is started and an autophagosome is formed, survivin expression is suppressed and apoptosis is executed. Harmol treatment reduced phosphorylation of Akt, mammalian target of rapamycin (mTOR) and its downstream targets p70-ribosomal protein S6 kinase and 4E-binding protein 1, resulting in induction of autophagy. Conversely, activation of the Akt/mTOR pathway inhibited harmol-induced autophagy and cell death. These findings indicate that harmol-induced autophagy involves the Akt/mTOR pathway. Taken together, autophagy induced by harmol represented a pro-apoptotic mechanism, and harmol suppressed the expression of survivin and subsequently induced apoptosis.

The ß-carboline alkaloid harmol induces cell death via autophagy but not apoptosis in human non-small cell lung cancer A549 cells.

ß-Carboline alkaloids are naturally occurring plant substances that have a wide spectrum of neuropharmacological, psychopharmacological, and antitumor effects. Recently, we have demonstrated that harmol, a ß-carboline alkaloid, induces apoptosis by caspase-8 activation independently from Fas/Fas ligand interaction in human non-small cell lung cancer (NSCLC) H596 cells. Here, we found that harmol induces autophagy and cell death in human NSCLC A549 cells. Although harmol induced cell death in A549 cells in a significant dose- and time-dependent manner, it did not induce caspase-3, caspase-8, or caspase-9 activity. Furthermore, cleavage of poly-(ADP-ribose)-polymerase was not induced in A549 cells by harmol treatment. Autophagy, but not apoptosis, was detected by electron microscopy in A549 cells treated with 70 µM harmol. Pretreatment of A549 cells with 3-methyladenine, an autophagy inhibitor, as well as small interfering RNA (siRNA)-mediated knockdown of LC3, both suppressed harmol-induced cell death. These suggest that the induction of autophagy by harmol precedes cell death. The cytotoxicity of some anticancer agents is reportedly linked to autophagy induction. The 2 major autophagy regulatory pathways are the Akt/mammalian target of rapamycin (mTOR) pathway and the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway. Although harmol treatment showed no effect on the Akt/mTOR pathway, it transiently activated the ERK1/2 pathway. However, inhibition of the ERK1/2 pathway using the mitogen-activated protein kinase (MEK)/ERK inhibitor U0126 partially suppressed autophagy. Therefore, although activation of the ERK1/2 pathway might be related to harmol-induced autophagy, another major pathway may also be involved in A549 cells.

D,L-Threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (DL-PDMP) increases endoplasmic reticulum stress, autophagy and apoptosis accompanying ceramide accumulation via ceramide synthase 5 protein expression in A549 cells.

In A549 cells, the addition of D,L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (DL-PDMP) led to marked autophagy with massive microtubule-associated protein 1 light chain 3B (LC3B)-II protein expression as an indication of autophagy and a steep decrease of p62 protein as a co-indication of autophagy. The addition of DL-PDMP caused massive autophagy with an increase of CAAT/enhancer binding protein homologous protein (CHOP) expression as the marker of endoplasmic reticulum (ER) stress, lactate dehydrogenase (LDH) release without caspase 3 activation and many autophagic vacuoles/devoid of a cell membrane on morphology. On the other hand, the addition of DL-PDMP caused an increase in cellular or subcellular ceramides (Cers), especially palmitoyl-Cer, based on de novo synthesis of Cer, and led to caspase-independent apoptosis. Marked increases of Cer levels in the nuclear envelope were observed 17 h after the addition. The elevations of Cer synthase activity and longevity-assurance homologue (LASS)5 protein expression were observed in subcellular fractions from 30 min until 2 h after the addition. However, the elevations of Cer synthase activity were independent of reactive oxygen species generation or cytochrome P450 4F2 activity. Since an increase in LASS5 protein expression in subcellular fraction occur in preference to the variation of LC3B-II protein expression via CHOP expression after the addition and Cer accumulation induced by the addition contributes to ER stress, it is thought that an elevation of Cer synthase activity via LASS5 protein expression associate to autophagy via CHOP expression (ER stress) with the addition.

Lorneic acids, trialkyl-substituted aromatic acids from a marine-derived actinomycete.

A marine-derived actinomyces strain (NPS554) isolated from a marine sediment sample collected from Miyazaki Harbor, Japan, at a depth of 38 m yielded two trialkyl-substituted aromatic acids, lorneic acid A (1) and lorneic acid B (2). The structures of the lorneic acids, which were elucidated by spectroscopic analysis, differed only in the side-chain, which contained either a conjugated double bond or a benzylic alcohol. Their structural differences affected inhibition activities against phosphodiesterase 5.

[Extraction method suitable for detection of unheated crustaceans including cephalothorax by ELISA].

When unheated whole samples of crustaceans (shrimp, prawn and crab) were analyzed with our ELISA kit (FA test EIA-Crustacean 'Nissui') using anti-tropomyosin antibodies, a remarkable reduction in reactivity was recognized. This reduction in activity was found to be due to the digestion of tropomyosin during the extraction process by proteases contained in cephalothorax. To avoid the digestion of tropomyosin by proteases, we developed an extraction method (heating method) suitable for the detection of tropomyosin in unheated crustaceans including cephalothorax. Experiments with unheated whole samples of various species of crustaceans confirmed that the heating method greatly improved the low reactivity in the standard method; the heating method gave extraction efficiencies of as high as 93-107%. Various processed crustaceans with cephalothorax, such as dry products (unheated or weakly heated products) and pickles in soy sauce (unheated products), that showed low reactivity with the standard method were confirmed to give superior results with the heating method. These results indicated that the developed heating method is suitable for detecting unheated crustaceans with cephalothorax by means of the ELISA kit.

Indoxamycins A-F. Cytotoxic tricycklic polypropionates from a marine-derived actinomycete.

Six antitumor antibiotics of a new structure class, indoxamycins A-F (1-6), were isolated from a saline culture group of marine-derived actinomyces whose strains showed approximately 96% sequence homology of 16S rDNA with the family streptomycetaceae. The structures of these indoxamycins, which are unusual polyketides composed of six consecutive chiral centers, were assigned by combined spectral and chemical methods. In feeding experiments using a stable isotope label, indoxamycin A was assembled from propionate units initially forming the "aglycon" pentamethyl indeno furan. The discovery of these unprecedented compounds from marine-derived actinomycetes, a low gene homology genus, offers a significant opportunity for drug discovery.

Harmol induces apoptosis by caspase-8 activation independently of Fas/Fas ligand interaction in human lung carcinoma H596 cells.

The beta-carboline alkaloids are naturally existing plant substances. It is known that these alkaloids have a wide spectrum of neuropharmacological, psychopharmacological, and antitumor effects. Therefore, they have been traditionally used in oriental medicine for the treatment of various diseases including cancers and malaria. In this study, harmol and harmalol, which are beta-carboline alkaloids, were examined for their antitumor effect on human lung carcinoma cell lines, and structure-activity relationship was also investigated. H596, H226, and A549 cells were treated with harmol and harmalol, respectively. Apoptosis was induced by harmol only in H596 cells. In contrast, harmalol had negligible cytotoxicity in three cell lines. Harmol induced caspase-3, caspase-8, and caspase-9 activities and caspase-3 activities accompanied by cleavage of poly-(ADP-ribose)-polymerase. Furthermore, harmol treatment decreased the native Bid protein, and induced the release of cytochrome c from mitochondria to cytosol. The apoptosis induced by harmol was completely inhibited by caspase-8 inhibitor and partially inhibited by caspase-9 inhibitor. The antagonistic antibody ZB4 blocked Fas ligand-induced apoptosis, but had no effect on harmol-induced apoptosis. Harmol had no significant effect on the expression of Fas. In conclusion, our results showed that the harmol could cause apoptosis-inducing effects in human lung H596 cells through caspase-8-dependent pathway but independent of Fas/Fas ligand interaction.

Interlaboratory evaluation of two enzyme-linked immunosorbent assay kits for the determination of crustacean protein in processed foods.

The labeling of foods containing material derived from crustaceans such as shrimp and crab is to become mandatory in Japan because of increases in the number of allergy patients. To ensure proper labeling, 2 novel sandwich enzyme-linked immunosorbent assay (ELISA) kits for the determination of crustacean protein in processed foods, the N kit (Nissui Pharmaceutical Co., Ltd, Ibaraki, Japan) and the M kit (Maruha Nichiro Holdings, Inc., Ibaraki, Japan), have been developed. Five types of model processed foods containing 10 and/or 11.9 microg/g crustacean soluble protein were prepared for interlaboratory evaluation of the performance of these kits. The N kit displayed a relatively high level of reproducibility relative standard deviation (interlaboratory precision; 4.0-8.4% RSDR) and sufficient recovery (65-86%) for all the model processed foods. The M kit displayed sufficient reproducibility (17.6-20.5% RSDR) and a reasonably high level of recovery (82-103%). The repeatability relative standard deviation (RSDr) values regarding the detection of crustacean proteins in the 5 model foods were mostly < 5.1% RSDr for the N kit and 9.9% RSDr for the M kit. In conclusion, the results of this interlaboratory evaluation suggest that both these ELISA kits would be very useful for detecting crustacean protein in processed foods.

Phenoxazine derivatives 2-amino-4,4alpha-dihydro-4alpha-phenoxazine-3-one and 2-aminophenoxazine-3-one-induced apoptosis through a caspase-independent mechanism in human neuroblastoma cell line NB-1 cells.

The aim of the present study was to determine whether phenoxazines such as 2-amino-4,4-alpha-dihydro-4alpha-phenoxazine-3-one (Phx-1) and 2-aminophenoxazine-3-one (Phx-3) may suppress the proliferation of human neuroblastoma cell line, NB-1 that is refractory to chemotherapeutic agents, inducing apoptosis through the activation of caspase pathway or not. Phx-1 and Phx-3 suppressed the proliferation of NB-1 cells extensively dependent on dose and time. The IC50 of Phx-1 and Phx-3 was about 20 microM and 0.5 microM, respectively, when the cells were treated with Phx-1 or Phx-3 for 72 h. Phx-1 and Phx-3 caused the mixed types of cell death-apoptosis and necrosis-in NB-1 cells, which was detected by flow cytometry. The induction of apoptosis/necrosis caused by these phenoxazines seemed to be correlated dominantly with the caspase independent pathway, because the increased activity of effector caspase 3/7 in NB-1 cells caused by 50 microM Phx-1 or 20 microM Phx-3 was completely cancelled by the addition of z-VAD-fmk, a pan-caspase inhibitor, but such phenoxazines-suppressed viability of NB-1 cells was not recovered to normal levels by this inhibitor. The results of this study demonstrate that Phx-1 and Phx-3 have antitumor activity against the neuroblastoma cell line, NB-1, though the IC50 was extremely low for Phx-3, inducing the mixed types of cell death, apoptosis and necrosis, caspase-independently.

Isolation and characterization of a cold-induced nonculturable suppression mutant of Vibrio vulnificus.

The viable but nonculturable (VBNC) suppression mutant formed platable cells at low temperature stress after inoculation in artificial seawater (ASW). Suppression subtractive hybridization was used to identify differentially expressed genes among cDNAs of the VBNC suppression mutant and the wild-type Vibrio vulnificus strain. Glutathione S-transferase was identified as a responsive gene of the VBNC suppression mutant in our assay, and was highly expressed from the VBNC suppression mutant at low temperature stress. Culturability tests revealed that the wild-type cells were sensitive to oxidative stress in the hydrogen peroxide (H(2)O(2)) and to 1-chloro-2,4-dinitrobenzene (CDNB) compared with the VBNC suppression mutant cells. Adding glutathione showed that many wild-type V. vulnificus cells maintained culturability in cold ASW. These results suggest that non-nutritional growth inhibitors, such as peroxide that accumulates at low temperatures, influence VBNC in V. vulnificus cells.

Phenoxazine derivatives induce caspase-independent cell death in human glioblastoma cell lines, A-172 and U-251 MG.

The apoptotic effects of 2-amino-4,4alpha-dihydro-4alpha, 7-dimethyl-3H-phenoxazine-3-one (Phx-1) and 2-aminophenoxazine-3-one (Phx-3) on human glioblastoma cell lines, A-172 and U-251 MG were studied. These phenoxazines extensively decreased the viability of A-172 and U-251 MG cells (IC50 of Phx-1: 60 microM, in both lines; IC50 of Phx-3: 10 and 3 microM, for A-172 and U-251 cells, respectively). Phx-1 and Phx-3 increased the population of annexin V and PI double-positive cells in A-172 and U-251 MG cells, resulting in cell death at late stage apoptosis/necrosis. The activities of caspase-3/7 were greatly increased in A-172 and U-251 MG cells treated with Phx-1 or Phx-3. However, a pan-caspase inhibitor, z-VAD-fmk, failed to reverse the antiproliferative and apoptotic effects of Phx-1 and Phx-3 in both cell lines. In conclusion, Phx-1 and Phx-3 exert significant anti-cancer effects against human glioblastoma cell lines, A-172 and U-251 MG, mediated by the caspase-independent apoptotic cell death pathway.

Lethality of shock pressures to a marine Vibrio sp. isolated from a ship's ballast water.

The lethal effects of shock pressure treatment on suspended Vibrio sp. cells were examined. Lethality of shock pressures to the Vibrio sp. cells increased with the increase in the values of maximum shock pressures generated in the cell suspension. When the value was around 114 MPa, the total number of colony-forming cells was reduced from 10(8.5+/-0.1) colony-forming units (CFU) to 10(3.3) - 10(3.4) CFU/ml, and complete loss of colony-forming ability was seen at the maximum value of 282 MPa. Almost all the cells could survive after the exposure to shock pressures including the maximum value of around 189 MPa in the presence of 2% sodium ascorbate (VitC-Na), whereas the total number of colony-forming cells was reduced to 10(1.6)-10(2.1) CFU/ml in the absence of VitC-Na. The surviving cells, however, showed sensitivity to 0.8% sodium cholate, a strong detergent. About 11% of cell-associated proteins had leaked out when the cells were exposed to lethal shock pressures including the maximum value of around 290 MPa in the absence of VitC-Na. These results indicate that the radicals generated in the cell suspension may be closely related to the loss of colony-forming ability of the Vibrio sp. cells. Damage to the outer membrane structure also seems to have occurred by the exposure to shock pressures.

Anticancer effects of phenoxazine derivatives combined with tumor necrosis factor-related apoptosis-inducing ligand on pancreatic cancer cell lines, KLM-1 and MIA-PaCa-2.

The aim of this study was to investigate the anticancer effects of the phenoxazine derivatives, 2-amino-4,4alpha-dihydro-4alpha,7-dimethyl-3H-phenoxazine-3-one (Phx-1), 3-amino-1,4alpha-dihydro-4alpha,8-dimethyl-2H-phenoxazine-2-one (Phx-2), and 2-aminophenoxazine-3-one (Phx-3) on human pancreatic cancer cell lines, KLM-1 and MIA-PaCa-2, in combination with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a member of the tumor necrosis factor superfamily of cytokines. Of these three phenoxazines, Phx-1 and Phx-3 inhibited proliferation of KLM-1 dose-dependently, but Phx-2 did not. Phx-3 caused both apoptosis and necrosis in KLM-1 cells, as evidenced by the phosphatidylserine externalization and propidium iodide permeable cells detected by a flow cytometric method using annexin-V and propidium iodide. Down-regulation of Bcl-2 expression appeared to be involved in the Phx-3-induced cell death. TRAIL did not affect proliferation of KLM-1, and the inhibitory effects of Phx-1 and Phx-3 on the KLM-1 cell line were not augmented by the combination with TRAIL. On the other hand, proliferation of the MIA-PaCa-2 cell line was not affected by Phx-1, Phx-2 and Phx-3, although it was significantly inhibited by TRAIL in a dose-dependent manner. Inhibitory effects of TRAIL on MIA-PaCa-2 were synergistically augmented by the addition of Phx-1 and Phx-3, but not by Phx-2. These results suggest that both Phx-1 and Phx-3 exert anticancer effects against human pancreatic cancer cells, KLM-1 and MIA-PaCa-2, through distinct action modes. Phx-1 and Phx-3 may be effective for the treatment of pancreatic cancer.