Fumi Utsumi

Effect of Indirect Nonequilibrium Atmospheric Pressure Plasma on Anti-Proliferative Activity against Chronic Chemo-Resistant Ovarian Cancer Cells In Vitro and In Vivo

Purpose 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. Methods 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. Results 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. Conclusion 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.

Plasma Medical Science for Cancer Therapy: Toward Cancer Therapy Using Nonthermal Atmospheric Pressure Plasma

We have been developing novel ultrahigh density atmospheric pressure plasma sources and succeeded in the selective killing ovarian cancer cells against normal ones. Furthermore, we have found out the plasma-activated medium (PAM) also killed glioblastoma brain tumor cells selectively against normal ones and the chemical products in the PAM have long lifetime healing effects. To clarify the mechanism, interactions of plasma with the organism and the medium where the organism belongs were investigated on the viewpoint of intracellular molecular mechanism.

Selective cytotoxicity of indirect nonequilibrium atmospheric pressure plasma against ovarian clear-cell carcinoma.

Ovarian clear cell carcinoma (CCC) is a histological type of epithelial ovarian cancer that is less responsive to chemotherapy and associated with a poorer prognosis than serous and endometrioid carcinoma. Non-thermal atmospheric pressure plasma which produces reactive species has recently led to an explosion of research in plasma medicine. Plasma treatment can be applied to cancer treatment to induce apoptosis and tumor growth arrest. Furthermore, recent studies have shown that a medium exposed to plasma also has an anti-proliferative effect against cancer in the absence of direct exposure to plasma. In this study, we confirmed whether this indirect plasma has an anti-tumor effect against CCC, and investigated whether this efficacy is selective for cancer cells. Non-thermal atmospheric pressure plasma induced apoptosis in CCC cells, while human peritoneal mesothelial cells remained viable. Non-thermal atmospheric pressure plasma exhibits selective cytotoxicity against CCC cells which are resistant to chemotherapy.

Non-thermal atmospheric pressure plasma activates lactate in Ringer’s solution for anti-tumor effects

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.

Variable susceptibility of ovarian cancer cells to non-thermal plasma-activated medium

Non-thermal atmospheric pressure plasma has been widely studied in recent years in many fields, including cancer treatment. However, its efficiency for inducing apoptosis sometimes varies depending on the cell species and experimental conditions. The aim of this study was to elucidate what causes these differences in responses to plasma treatment. Using four ovarian cancer cell lines, the cell density had a markedly negative impact on the proliferation inhibition rate (PIR) and it was more obvious in OVCAR-3 and NOS2 cells. Furthermore, TOV21G and ES-2 cells were drastically sensitive to plasma-activated medium (PAM) compared with the other two cell lines. We demonstrated that the proportion of reactive oxygen species and cell number had a marked impact on the effect of PAM against ovarian cancer cells. Additionally it was suggested that the morphological features of cells were also closely related

Perspective of strategic plasma therapy in patients with epithelial ovarian cancer: A short review of plasma in cancer treatment

Epithelial ovarian cancer (EOC) is the leading cause of cancer-related death in women in Western countries. Once patients experience recurrence, complete cure is almost impossible. Nonequilibrium atmospheric pressure plasma (NEAPP) therapy has recently been focused on as a novel medical practice. We have elucidated the effect of nonequilibrium atmospheric pressure plasma on the growth of EOC, particularly in plasma-activated medium (PAM). In our recent report, we examined the role of reactive oxygen species (ROS) or their scavengers in chronic antineoplastic-resistant EOC cells. As a result, PAM exerted the antitumor effect of EOC cells in vitro and in vivo, even in chemoresistant cells. There are several problems under investigation, including intracellular mechanism of antitumor effect by PAM and adverse event in vivo. Through recent results about plasma in cancer treatment, PAM therapy is a promising treatment option for EOC and may contribute to a better patient prognosis in the future.

Efficacy of glypican-3-derived peptide vaccine therapy on the survival of patients with refractory ovarian clear cell carcinoma

ABSTRACT Compared with other epithelial ovarian carcinoma subtypes, ovarian clear cell carcinoma (OCCC) has been recognized to show chemoresistance. Therefore, new treatment modalities are required for patients with OCCC that is refractory to chemotherapy. The carcinoembryonic antigen glypican-3 (GPC3) is expressed by approximately half of OCCC and is a promising immunotherapeutic target. The purpose of this study was to evaluate the effect of GPC3 peptide vaccine against refractory OCCC patients. We conducted a phase II trial with a GPC3-derived peptide vaccine in OCCC patients. Immunological responses were analyzed by ex vivo IFNγ ELISPOT assay. We also evaluated control subjects, who received best supportive care without vaccinations during the same period. Thirty-two patients with refractory OCCC were enrolled between July 2010 and September 2015, and underwent GPC3 peptide vaccination. Fifteen patients were vaccinated less than six times because their general condition progressively deteriorated, and 17 patients were vaccinated at least six times. Three patients showed a partial response as the best overall response. The GPC3 peptide vaccine induced a GPC3-specific CTL response in 15 out of 24 patients who had PBMCs collected three times or more. The prognosis of palliative care patients without GPC3 peptide vaccinations was significantly poorer than that of those with GPC3 peptide vaccinations (post cancer-treatment survival: p = 0.002). Although the disease control rate was not high, our results suggest that GPC3 peptide vaccinations may hold a significant impact to prolong survival of patients with refractory OCCC, allowing them to maintain quality of life with no serious toxicities.

Novel Intraperitoneal Treatment With Non-Thermal Plasma-Activated Medium Inhibits Metastatic Potential of Ovarian Cancer Cells

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.

Future perspective of strategic non-thermal plasma therapy for cancer treatment

The therapeutic effects of non-thermal plasma are expected in the medical fields, including hemostasis, vascularization, prevention of organ adhesion, and cell proliferation. Cancer is an internal enemy arising from normal tissue in the body. The prognosis of metastatic and recurrent cancers is still poor despite advances in medicine. To apply non-thermal plasma in cancer treatment is now on going. The mechanism of the proliferation-inhibitory effect of plasma is reactive nitrogen oxide species/reactive oxygen species production in cells. There are a number of problems to be overcome, such as existence of intrinsic reactive oxygen species/reactive nitrogen species scavengers and the shallow infiltration of plasma on tumor surface. The current reviews makes referral to the study results of plasma therapy clarified so far, the possibility of its application in the future.

Feasibility and benefit of concurrent chemoradiotherapy for elderly patients with uterine cervical cancer.

Background Elderly patients with uterine cervical cancer reportedly have a poorer prognosis than younger patients. Until now, the benefit of concurrent chemoradiotherapy (CCRT) for elderly patients has been considered limited. Methods We retrospectively analyzed 49 women with cervical cancer aged >70 years primarily treated with radiotherapy (RT) or CCRT in our institute between 2003 and 2014. Treatment compliance, toxicity, and survival benefit were analyzed. Results A total of 49 patients were identified in this retrospective analysis. Twenty patients with a median age of 75.4 years (range 70–77) were treated with CCRT and 29 patients with a median age of 77.9 years (range 70–89) underwent RT. In the CCRT group, 14 patients (70%) completed CCRT consisting of radiotherapy and 5 courses of cisplatin plus 5-fluorouracil including patients requiring a dose reduction of chemotherapy. The median overall survival (OS) in the CCRT and RT groups was 66.9 and 60.1 months, respectively (p = 0.156). The most common grade 3/4 acute toxicity was hyponatremia (35.0%), followed by neutropenia (15.0%) and diarrhea (10.0%) in the CCRT group, while this was anemia (17.2%) followed by radiation enteritis (10.3%) in the RT group. Conclusions CCRT was well tolerated in elderly patients with cervical cancer. Careful attention should be paid to the different characteristics of treatment-related toxicities in this group compared with younger patients.