Non-equilibrium atmospheric pressure plasmas generate a high electron density (on the order of 1016 electrons per cm−3) using Ar gas. Culture medium in air at room temperature was plasma-irradiated ...for several hundred seconds. Tens of micromolar hydrogen peroxide (H2O2) and millimolar levels of nitrous ion (NO2−) were detected in the plasma-irradiated culture medium (plasma activated medium; PAM) and selectively induced the apoptotic death of glioblastoma tumor cells, but did not kill normal mammary epithelial cells. A similar antitumor effect was induced by spiking the medium with comparable concentrations of H2O2 and NO2−. The PAM remained still a somewhat difference that it should also be assessed for understanding other latent mechanisms.
Display omitted
•Induction by PAM of apoptosis in glioblastoma but not in normal epithelial cells.•Quantitative analysis of H2O2 and NO2− concentrations in PAM.•Cancer kill by H2O2 and NO2− in non-treated medium at concentrations same as PAM.•Evidence of a synergism of H2O2 and NO2− on selective kill upon incubation in PAM.•The antitumor effect of PAM is not due solely to the synergism of H2O2 and NO2−.
Nonequilibrium atmospheric pressure plasma (NEAPP) therapy has recently been focused on as a novel medical practice. Using cells with acquired paclitaxel/cisplatin resistance, we elucidated effects ...of indirect NEAPP-activated medium (NEAPP-AM) exposure on cell viability and tumor growth in vitro and in vivo.
Using chronic paclitaxel/cisplatin-resistant ovarian cancer cells, we applied indirect NEAPP-exposed medium to cells and xenografted tumors in a mouse model. Furthermore, we examined the role of reactive oxygen species (ROS) or their scavengers in the above-mentioned EOC cells.
We assessed the viability of NOS2 and NOS3 cells exposed to NEAPP-AM, which was prepared beforehand by irradiation with NEAPP for the indicated time. In NOS2 cells, viability decreased by approximately 30% after NEAPP-AM 120-sec treatment (P<0.01). The growth-inhibitory effects of NEAPP-AM were completely inhibited by N-acetyl cysteine treatment, while L-buthionine-S, R-sulfoximine, an inhibitor of the ROS scavenger used with NEAPP-AM, decreased cell viability by 85% after NEAPP-AM 60-sec treatment(P<0.05) and by 52% after 120 sec, compared to the control (P<0.01). In the murine subcutaneous tumor-formation model, NEAPP-AM injection resulted in an average inhibition of the NOS2 cell-inoculated tumor by 66% (P<0.05) and NOS2TR cell-inoculated tumor by 52% (P<0.05), as compared with the control.
We demonstrated that plasma-activated medium also had an anti-tumor effect on chemo-resistant cells in vitro and in vivo. Indirect plasma therapy is a promising treatment option for EOC and may contribute to a better patient prognosis in the future.
Non-thermal atmospheric pressure plasma is a novel approach for wound healing, blood coagulation, and cancer therapy. A recent discovery in the field of plasma medicine is that non-thermal ...atmospheric pressure plasma not only directly but also indirectly affects cells via plasma-treated liquids. This discovery has led to the use of non-thermal atmospheric pressure plasma as a novel chemotherapy. We refer to these plasma-treated liquids as plasma-activated liquids. We chose Ringer's solutions to produce plasma-activated liquids for clinical applications. In vitro and in vivo experiments demonstrated that plasma-activated Ringer's lactate solution has anti-tumor effects, but of the four components in Ringer's lactate solution, only lactate exhibited anti-tumor effects through activation by non-thermal plasma. Nuclear magnetic resonance analyses indicate that plasma irradiation generates acetyl and pyruvic acid-like groups in Ringer's lactate solution. Overall, these results suggest that plasma-activated Ringer's lactate solution is promising for chemotherapy.
Non-thermal atmospheric pressure plasma has been proposed as a new therapeutic tool for cancer treatment. Recently, plasma-activated medium (PAM) has been widely studied in various cancer types. ...However, there are only few reports demonstrating the anti-tumour effects of PAM in an animal model reflecting pathological conditions and the accompanying mechanism. Here we investigated the inhibitory effect of PAM on the metastasis of ovarian cancer ES2 cells in vitro and in vivo. We demonstrated that ES2 cell migration, invasion and adhesion were suppressed by PAM at a certain PAM dilution ratio, whereas cell viability remained unaffected. In an in vivo mouse model of intraperitoneal metastasis, PAM inhibited peritoneal dissemination of ES2 cells, resulting in prolonged survival. Moreover, we assessed the molecular mechanism and found that MMP-9 was decreased by PAM. On further investigation, we also found that PAM prevented the activation of the MAPK pathway by inhibiting the phosphorylation of JNK1/2 and p38 MAPK. These findings indicate that PAM inhibits the metastasis of ovarian cancer cells through reduction of MMP-9 secretion, which is critical for cancer cell motility. Our findings suggest that PAM intraperitoneal therapy may be a promising treatment option for ovarian cancer.
Low-temperature plasma is being widely used in the various fields of life science, such as medicine and agriculture. Plasma-activated solutions have been proposed as potential cancer therapeutic ...reagents. We previously reported that plasma-activated Ringer's lactate solution exhibited selective cancer-killing effects, and that the plasma-treated L-sodium lactate in the solution was an anti-tumor factor; however, the components that are generated through the interactions between plasma and L-sodium lactate and the components responsible for the selective killing of cancer cells remain unidentified. In this study, we quantified several major chemical products, such as pyruvate, formate, and acetate, in plasma-activated L-sodium lactate solution by nuclear magnetic resonance analysis. We further identified novel chemical products, such as glyoxylate and 2,3-dimethyltartrate, in the solution by direct infusion-electrospray ionization with tandem mass spectrometry analysis. We found that 2,3-dimethyltartrate exhibited cytotoxic effects in glioblastoma cells, but not in normal astrocytes. These findings shed light on the identities of the components that are responsible for the selective cytotoxic effect of plasma-activated solutions on cancer cells, and provide useful data for the potential development of cancer treatments using plasma-activated L-sodium lactate solution.
We explored risk indicators likely to result in older adults needing certified long-term care in Japan and ascertained whether this relationship forms a U-shaped link. We analyzed a community-based ...cohort of residents in Kitanagoya City, Aichi Prefecture, Japan. Participants were 3718 individuals aged 65 years and above who underwent health examinations between April 1, 2011 and March 31, 2012. For continuous clinical variables, we applied a time-dependent Cox regression model. Two types of models were applied-a linear and nonlinear model with restricted cubic splines-to assess the U-shaped association. Statistical significance (set at 0.05) for the nonlinearity was tested by comparing the spline and linear models. Among the participants, 701 were certified as needing Level 1 care or higher during a follow-up. Among the continuous clinical variables, the nonlinear model for body mass index, systolic blood pressure, high-density lipoprotein cholesterol, alanine aminotransferase, aspartate aminotransferase, and γ-glutamyl transpeptidase revealed significant U-shaped associations as compared with the linear model in which the outcome was a certification of the need for nursing care. These results provide an important insight into the usefulness of nonlinear models for predicting the risk of such certification.
Background
The medical applications of nonequilibrium atmospheric pressure plasma in cancer therapy have attracted attention. We previously reported on the antitumor effect of plasma-activated ...medium. However, this approach requires plasma-activated liquids that are administrable to the human body. In this study, we produced plasma-activated lactated Ringer’s solution (PAL) and evaluated its antitumor effect and mechanism. Furthermore, we evaluated the effect of the intraperitoneal administration of PAL using a peritoneal dissemination mouse tumor model.
Methods
The antitumor effect of PAL on pancreatic cancer cell lines was evaluated using proliferation and apoptosis assays. In addition, cellular reactive oxygen species (ROS) generation was examined. The role of ROS was assessed using a proliferation assay with N-acetyl cysteine (NAC). An adhesion assay was performed to evaluate the effect of PAL on cell adhesion. Finally, pancreatic cancer cells stably expressing luciferase (AsPC-1/CMV-Luc) were injected intraperitoneally into mice, followed by intraperitoneal injection of PAL. Peritoneal dissemination was monitored using in vivo bioluminescent imaging.
Results
The antitumor effect of PAL was shown in all cell lines in vitro. The TUNEL assay showed that PAL induced apoptosis. ROS uptake was observed in PAL-treated cells, and the antitumor effect was inhibited by NAC. Cell adhesion also was suppressed by PAL. The intraperitoneal administration of PAL suppressed the formation of peritoneal nodules in vivo.
Conclusions
Our study demonstrated the antitumor effects of PAL in vitro and in vivo. Intraperitoneal administration of PAL may be a novel therapeutic option for peritoneal metastases.
The biological function of non-thermal atmospheric pressure plasma has been widely accepted in several types of cancer. We previously developed plasma-activated medium (PAM) for clinical use, and ...demonstrated that PAM exhibits a metastasis-inhibitory effect on ovarian cancer through reduced MMP-9 secretion. However, the anti-tumor effects of PAM on endometrial cancer remain unknown. In this study, we investigated the inhibitory effect of PAM on endometrial cancer cell viability in vitro. Our results demonstrated that AMEC and HEC50 cell viabilities were reduced by PAM at a certain PAM ratio, and PAM treatment effectively increased autophagic cell death in a concentration dependent manner. In addition, we evaluated the molecular mechanism of PAM activity and found that the mTOR pathway was inactivated by PAM. Moreover, our results demonstrated that the autophagy inhibitor MHY1485 partially inhibited the autophagic cell death induced by PAM treatment. These findings indicate that PAM decreases the viability of endometrial cancer cells along with alteration of the mTOR pathway, which is critical for cancer cell viability. Collectively, our data suggest that PAM inhibits cell viability while inducing autophagic cell death in endometrial cancer cells, representing a potential novel treatment for endometrial cancer.
Background:The Therapeutic Angiogenesis by Cell Transplantation (TACT) trial demonstrated the efficacy and safety of autologous bone marrow-derived mononuclear cells (BM-MNCs) in patients with ...critical limb ischemia (CLI). The present study aimed to assess the long-term clinical outcomes of therapeutic angiogenesis using autologous BM-MNC implantation under advanced medical treatment in Japan.Methods and Results:The study was retrospective, observational, and non-controlled. We assessed no-option CLI patients who had BM-MNC implantation performed in 10 institutes. Overall survival (OS), major amputation-free (MAF), and amputation-free survival (AFS) rates were primary endpoints of this study. The median follow-up duration was 31.7 months. The 10-year OS rate was 46.6% in patients with arteriosclerosis obliterans (ASO) (n=168), 90.5% in patients with thromboangiitis obliterans (TAO) (n=108), and 67.6% in patients with collagen disease-associated vasculitis (CDV) (n=69). The 10-year MAF rate was 70.1%, 87.9%, and 90.9%, respectively. The 10-year AFS rate was 37.8%, 80.9%, and 61.2%, respectively. Major adverse cardiovascular events occurred in 6.0% of patients with ASO, 1.9% of patients with TAO, and no patients with CDV.Conclusions:Therapeutic angiogenesis using autologous BM-MNC implantation may be feasible and safe in patients with no-option CLI, particularly those with CLI caused by TAO or CDV.
Non-thermal plasma (NTP) is a potential new therapeutic modality for cancer. However, its mechanism of action remains unclear. Herein, we studied the effect of NTP on mesothelioma cells and ...fibroblasts to understand its anti-proliferative efficacy. Interestingly, NTP demonstrated greater selective anti-proliferative activity against mesothelioma cells relative to fibroblasts than cisplatin, which is used for mesothelioma treatment. The anti-proliferative effect of NTP was enhanced by pre-incubation with the cellular iron donor, ferric ammonium citrate (FAC), and inhibited by iron chelation using desferrioxamine (DFO). Three oxidative stress probes (CM-H2DCFDA, MitoSOX and C11-BODIPY) demonstrated reactive oxygen species (ROS) generation by NTP, which was inhibited by DFO. Moreover, NTP decreased transferrin receptor-1 and increased ferritin-H and -L chain expression that was correlated with decreased iron-regulatory protein expression and RNA-binding activity. This regulation was potentially due to increased intracellular iron in lysosomes, which was demonstrated via the Fe(II)-selective probe, HMRhoNox-M, and was consistent with autophagic-induction. Immunofluorescence using LysoTracker and Pepstatin A probes demonstrated increased cellular lysosome content, which was confirmed by elevated LAMP1 expression. The enhanced lysosomal biogenesis after NTP could be due to the observed increase in fluid-phase endocytosis and early endosome formation. These results suggest NTP acts as a stressor, which results in increased endocytosis, lysosome content and autophagy. In fact, NTP rapidly increased autophagosome formation, as judged by increased LC3B-II expression, which co-localized with LAMP1, indicating autophagolysosome formation. Autophagic-induction by NTP was confirmed using electron microscopy. In summary, NTP acts as a cellular stressor to rapidly induce fluid-phase endocytosis, lysosome biogenesis and autophagy.
Display omitted
•Non-thermal plasma (NTP) is a potential new therapeutic modality for cancer.•Malignant mesothelioma cells were more sensitive to NTP than fibroblasts.•Anti-proliferative effect of NTP was dependent on iron and oxidative stress.•NTP significantly increased catalytic Fe(II) in mesothelioma cells.•NTP increased fluid-phase endocytosis, lysosome biogenesis and autophagy.