Hiroko Mitsui

Glyoxal and methylglyoxal trigger distinct signals for map family kinases and caspase activation in human endothelial cells

Carbonyl compounds with diverse carbon skeletons may be differentially related to the pathogenesis of vascular diseases. In this study, we compared intracellular signals delivered into cultured human umbilical vein endothelial cells (HUVECs) by glyoxal (GO) and methylglyoxal (MGO), which differ only by a methyl group. Depending on their concentrations, GO and MGO promoted phosphorylations of ERK1 and ERK2, which were blocked by the protein-tyrosine kinase (PTK) inhibitors herbimycin A and staurosporine, thereby being PTK-dependent. GO and MGO also induced phosphorylations of JNK, p38 MAPK, and c-Jun, either PTK-dependently (GO) or -independently (MGO). Next, we found that MGO, but not GO, induced degradation of poly(ADP-ribose) polymerase (PARP) as the intracellular substrate of caspase-3. Curcumin and SB203580, which inhibit JNK and p38 MAPK signaling pathways, but not herbimycin A/staurosporine, prevented the MGO-induced PARP degradation. We then found that MGO, but not GO, reduced the intracellular glutathione level, and that cysteine, but not cystine, inhibited the MGO-mediated activation of ERK, JNK, p38 MAPK, or c-Jun more extensively than did lysine or arginine. In addition, all the signals triggered by GO and MGO were blocked by amino guanidine (AG), which traps carbonyls. These results demonstrated that GO and MGO triggered two distinct signal cascades, one for PTK-dependent control of ERK and another for PTK-independent redox-linked activation of JNK/p38 MAPK and caspases in HUVECs, depending on the structure of the carbon skeleton of the chemicals.

Functional interaction between peritoneal mesothelial cells and stem cells of ovarian yolk sac tumor (SC-OYST) in peritoneal dissemination

OBJECTIVE In recent years it has been indicated that ecological niches play important roles in the maintenance of cancer stem cells (CSCs). We investigated interactions between peritoneal mesothelial cells and SC-OYST based on the hypothesis that peritoneal mesothelial cells have the potential to provide one of the niches for SC-OYST. METHODS We divided NOY1 cells into CD133-positive and -negative cells. Using the co-culture of NOY1 and peritoneal mesothelial cells, we compared the expression of CD133, colony formation, and the capacity for migration and invasion. In addition, we assessed the inhibitory effects of AMD3100, a neutralizing antibody against a chemokine receptor (CXCR4). Then, we examined whether AMD3100 affects the tumorigenicity of NOY1-CD133+ cells in vivo. RESULTS When NOY1 cells were co-cultured with peritoneal mesothelial cells, we observed the high-level expression of CD133. The number of colonies of NOY1-CD133+ cells was 2.4 times that of NOY1-CD133- cells. In contrast, on co-culture with peritoneal mesothelial cells, it was 4.3 times. When NOY1 cells were cultivated in the upper layer and peritoneal mesothelial cells were cultivated in the lower chamber, NOY1-CD133+ cells showed a greater capacity for migration and invasion than NOY1-CD133- cells. By adding AMD3100 to the co-culture systems, the colony formation, migration, and invasion of NOY1-CD133+ cells were inhibited. In addition, AMD3100 inhibited the tumorigenicity of NOY1-CD133+ cells in vivo. CONCLUSIONS Our data suggest that peritoneal mesothelial cells have the potential to provide one of the niches for NOY1 cells. Investigation of the niches of SC-OYST will help elucidate important targets for therapeutic approaches.

Possible association between stem-like hallmark and radioresistance in human cervical carcinoma cells

We aimed to investigate the possibility of an association between a stem‐like hallmark and radiotherapeutic sensitivity in human cervical carcinoma cells.

Survival benefit of taxane plus platinum in recurrent ovarian cancer with non-clear cell, non-mucinous histology

Objective This study was conducted to examine the effects of front-line chemotherapy on overall survival (OS) and postrecurrence survival (PRS) of patients with recurrent ovarian cancer, when stratifying the histologic type. Methods Five hundred and seventy-four patients with recurrent ovarian cancer with sufficient clinical information, including front-line chemotherapy, were analyzed. The pathologic slides were evaluated by central pathologic review. The patients were divided into two groups: group A (n=261), who underwent taxane plus platinum, and group B (n=313), who underwent conventional platinum-based chemotherapy without taxanes. Results The median age was 54 years (range, 14 to 89 years). Group A had significantly better median OS (45.0 months vs. 30.3 months, p<0.001) and PRS (23.0 months vs. 13.0 months, p<0.001) compared to group B. The OS and PRS were similar between the groups in patients with clear cell or mucinous histology. In contrast, among patients with non-clear cell, non-mucinous histologies, the OS and PRS of group A were significantly better than those of group B (OS, p<0.001; PRS, p<0.001). Multivariable analyses revealed that, among patients with non-clear cell, non-mucinous histologies, chemotherapy including taxane and platinum was an independent predictor of favorable survival outcomes. Conversely, in patients with clear cell or mucinous histology, taxane-including platinum-based combination chemotherapy did not improve the OS and PRS compared to a conventional platinum-based regimen which did not include taxanes. Conclusion Since the emergence of taxane plus platinum, the prognosis of patients with recurrent ovarian cancer has improved. However, we here demonstrate that this improvement is limited to patients with non-clear cell, non-mucinous histologies.

PRIMA-1MET induces apoptosis through accumulation of intracellular reactive oxygen species irrespective of p53 status and chemo-sensitivity in epithelial ovarian cancer cells

There is an intensive need for the development of novel drugs for the treatment of epithelial ovarian cancer (EOC), the most lethal gynecologic malignancy due to the high recurrence rate. TP53 mutation is a common event in EOC, particularly in high-grade serous ovarian cancer, where it occurs in more than 90% of cases. Recently, PRIMA-1 and PRIMA-1MET (p53 reactivation and induction of massive apoptosis and its methylated form) were shown to have an antitumor effect on several types of cancer. Despite that PRIMA-1MET is the first compound evaluated in clinical trials, the antitumor effects of PRIMA-1MET on EOC remain unclear. In this study, we investigated the therapeutic potential of PRIMA-1MET for the treatment of EOC cells. PRIMA-1MET treatment of EOC cell lines (n=13) resulted in rapid apoptosis at various concentrations (24 h IC50 2.6–20.1 µM). The apoptotic response was independent of the p53 status and chemo-sensitivity. PRIMA-1MET treatment increased intracellular reactive oxygen species (ROS), and PRIMA-1MET-induced apoptosis was rescued by an ROS scavenger. Furthermore, RNA expression analysis revealed that the mechanism of action of PRIMA-1MET may be due to inhibition of antioxidant enzymes, such as Prx3 and GPx-1. In conclusion, our results suggest that PRIMA-1MET represents a novel therapeutic strategy for the treatment of ovarian cancer irrespective of p53 status and chemo-sensitivity.

Oncologic outcome after recurrence in patients with stage I epithelial ovarian cancer: are clear-cell and mucinous histological types a different entities?

OBJECTIVES This study was conducted to estimate the oncologic outcome of stage I epithelial ovarian carcinoma (EOC) patients after recurrence. STUDY DESIGN After central pathological review and searching of the medical records of multi-institutions, a total of 103 relapsed patients with stage I EOC were analyzed. The major endpoint was postrecurrence survival (PRS). RESULTS The median follow-up for surviving patients was 57.5 (5.7-242.0) months. The median age was 52 (14-89). Among the patients, 19 (18.4%) had FIGO IA disease, and 4 (3.9%) and 80 (77.7%) had IB and IC disease, respectively. Regarding the histological type, the clear-cell type was the most frequently observed (N=42: 40.8%). The 3/5-year overall and PRS rates of all patients were 63.7/47.9 and 38.2/24.0%, respectively. The 5-year PRS rates of patients with serous, endometrioid, clear-cell, and mucinous tumors were 44.9, 35.0, 19.8, and 0%, respectively. On stratifying by the histological type, the overall and postrecurrence survival rates of patients with the mucinous/clear-cell types were significantly poorer than in those with the non-mucinous/clear-cell types (OS: P=0.0253, PRS: P=0.0016). In multivariate analyses, the FIGO stage (IA/IB vs. IC) and histological type (clear-cell/mucinous vs. non- clear-cell/mucinous) retained their significance as prognostic factors of a poorer PRS {stage IC (vs. IA/B) HR 2.176 (95% CI: 1.059-4.470), P=0.0343: clear-cell/mucinous (vs. non- clear-cell/mucinous): HR: 2.486(95% CI: 1.416-4.364), P=0.0015). CONCLUSIONS Even if at stage I, once patients with a mucinous/clear-cell histology experience recurrence, subsequent survival is extremely poor.

The expression and characterization of endoglin in uterine leiomyosarcoma

Endoglin (CD105), an accessory receptor of transforming growth factor-β, is expressed in vascular endothelial cells. Recently, it was reported that endoglin expression was significantly associated with poorer survival in several cancers. In this study, we evaluated the role of endoglin in uterine leiomyosarcoma. We examined the expression of endoglin in 22 uterine leiomyosarcomas and the association between their expression and the outcome. Additionally, to evaluate the function of endoglin, we used SKN cells, a human uterine leiomyosarcoma cell line. We generated SKN cells stably transfected with plasmids encompassing shRNA targeting endoglin (shEng cells), and compared the ability of proliferation, migration, and invasion to control shRNA-transfected cells (shCon cells). We compared the level of VEGF and matrix metalloproteinases (MMP) in culture supernatants of shEndoglin and shControl cells. Nine patients were endoglin-positive and 13 patients were -negative. The endoglin-positive group had a significantly poorer overall survival and progression-free survival than the endoglin-negative group. In an in vitro study, there was no difference in cell proliferation between shEng and shCon cells. On the other hand, shEng cells showed a lower ability for migration and invasion than shControl cells. The activity of MMP-9 and VEGF level in the supernatant from shEng cells were lower than in shCon cells. In uterine leiomyosarcoma, endoglin expression was associated with a poor prognosis. It was suggested that endoglin up-regulated invasion and VEGF secretion. The investigation of endoglin may lead to a new strategy in uterine leiomyosarcoma therapy.

A novel mechanism of neovascularization in peritoneal dissemination via cancer-associated mesothelial cells affected by TGF-β derived from ovarian cancer

Epithelial ovarian cancer (EOC) is believed to cause peritoneum dissemination through microenvironmental cell‑to-cell communication between the tumor and mesothelium, leading to the further acquisition of progressive and metastatic potentials. In the present study, we aimed to determine the role of cancer-associated mesothelial cells (CAMCs) in the promotion of tumor neovascularization and vascular permeability via enhanced vascular endothelial growth factor (VEGF) production. We examined whether a characteristic morphological change in human peritoneal mesothelial cells (HPMCs) was observed in the presence of malignant ascites and tumor-derived TGF-β. We focused on the enhanced production of VEGF in CAMCs and its crucial role in endothelial migration and tube formation. Normal HPMCs showed an epithelial morphology with a cobblestone appearance. When HPMCs were co-cultured with malignant ascites from patients with advanced EOC, a dramatic morphologic change was noted from an epithelioid pattern to an α-SMA-positive fibroblastic, mesenchymal pattern. Additionally, we found that EOC-derived TGF-β induced typical EMT-like morphological alteration in HPMCs, which was associated with CAMCs. We further discovered that CAMCs play a crucial role in the enhanced migration and tube formation of endothelial cells by the promotion of VEGF production. In conclusion, our findings indicate the possible involvement of CAMCs in the neovascularization of EOC and enhancement of vascular permeability, resulting in the formation of malignant ascites. The novel mechanism of CAMCs as a facilitator of EOC progression is displayed by microenvironmental cell-to-cell communication between EOC and the mesothelium.

Radiotherapy for persistent malignant transformation from mature cystic teratoma of the ovary.

Malignant transformations of mature cystic teratomas (MCT) are extremely rare and most of them are squamous cell carcinomas (SCC). Therefore no effective postoperative treatment has been established. In this article, we report two cases in which radiotherapy was effective for SCC arising from MCT. Case 1 was a 64‐year‐old woman with stage IIA of this tumor. After primary surgery, chemotherapy and interval debulking surgery were performed. She received radiotherapy for relapsed tumors, and has been well for 36 months since the initial diagnosis. Case 2 was a 37‐year‐old woman with stage IIB of this tumor. After primary debulking surgery, she received chemoradiotherapy for a residual tumor and has been well for 27 months since the surgery. Although there is no established therapy, radiotherapy or concurrent chemoradiotherapy might have beneficial effects on this tumor, similarly to those on SCC from other tissue.