Tetsuo Nagasaka

Indoleamine 2,3-dioxygenase is a novel prognostic indicator for endometrial cancer

Indoleamine 2,3-dioxygenase (IDO) is a tryptophan-catabolising enzyme inducing immune tolerance. The present study aimed to investigate IDO expression and its prognostic significance in endometrial cancer. Indoleamine 2,3-dioxygenase expression in endometrial cancer tissues (n=80) was immunohistochemically scored as four groups (IDO−, 1+, 2+, and 3+). The high IDO expression (IDO2+ or 3+) in tumour cells was found in 37 (46.3%) of the 80 cases, and was positively correlated with surgical stage, myometrial invasion, lymph-vascular space involvement, and lymph node metastasis, but not with the histological grade. Patients with high IDO expression had significantly impaired overall survival and progression-free survival (PFS) (P=0.002 and P=0.001, respectively) compared to patients with no or weak expression of IDO (IDO− or 1+). The 5-year PFS for IDO−/1+, 2+, and 3+ were 97.7, 72.9, and 36.4%, respectively. Even in patients with early-stage disease (International Federation of Gynecology and Obstetrics I/II, n=64), the PFS for IDO2+/3+ was significantly poor (P=0.001) compared to that for IDO−/1+. On multivariate analysis, IDO expression was an independent prognostic factor for PFS (P=0.020). These results indicated that the high IDO expression was involved in the progression of endometrial cancer and correlated with the impaired clinical outcome, suggesting that IDO is a novel and reliable prognostic indicator for endometrial cancer.

Angiotensin II type 1 receptor expression in ovarian cancer and its correlation with tumour angiogenesis and patient survival

Angiotensin II, a main effector peptide in the renin–angiotensin system, acts as a growth-promoting and angiogenic factor via type 1 angiotensin II receptors (AT1R). We have recently demonstrated that angiotensin II enhanced tumour cell invasion and vascular endothelial growth factor (VEGF) secretion via AT1R in ovarian cancer cell lines in vitro. The aim of the present study was to determine whether AT1R expression in ovarian cancer is correlated with clinicopathological parameters, angiogenic factors and patient survival. Immunohistochemical staining for AT1R, VEGF, CD34 and proliferating cell nuclear antigen (PCNA) were analysed in ovarian cancer tissues (n=67). Intratumour microvessel density (MVD) was analysed by counting the CD34-positive endothelial cells. Type 1 angiotensin II receptors were expressed in 85% of the cases examined, of which 55% were strongly positive. Type 1 angiotensin II receptors expression was positively correlated with VEGF expression intensity and MVD, but not with histological subtype, grade, FIGO stage or PCNA labelling index. In patients who had positive staining for AT1R, the overall survival and progression-free survival were significantly poor (P=0.041 and 0.017, respectively) as compared to those in patients who had negative staining for AT1R, although VEGF, but not AT1R, was an independent prognostic factor on multivariate analysis. These results demonstrated that AT1R correlated with tumour angiogenesis and poor patient outcome in ovarian cancer, suggesting its clinical potential for a novel molecular target in strategies for ovarian cancer treatment.

Fertility-sparing surgery in young women with invasive epithelial ovarian cancer

OBJECTIVES The purpose of this study was to clarify the clinical outcome of patients with stage IA or more advanced epithelial ovarian cancer (EOC) treated with fertility-sparing surgery (FSS). METHODS After a central pathological review and search of the medical records from multiple institutions, a total of 60 stage I EOC patients treated with FSS were retrospectively evaluated in the current study. RESULTS The median age was 30 years (range: 12-40 years). The median follow-up time was 54.7 months (range: 4.8-243.8 months). The stage was IA in 30, IB in one, and IC in 29 patients. Fifty-two patients were alive without relapse and 8 patient experienced recurrences {IA, 2; IB, 1; IC(surface involvement), 1; and IC(positive cytology), 4}. However, all patients with stage IC(capsule rupture) (n=17) were alive without recurrence. Collectively, there was no significant difference in the overall survival between the stage IA and IC groups (P=0.256). Moreover, there was no significant difference in DFS and OS between patients with stage IC(capsule rupture) and those with stage IA. In contrast, DFS and OS of the patients with stage IC(surface involvement/positive cytology) were poorer than those of patients with stage IA {OS; P=0.030, and DFS; P=0.005, respectively}. Thirteen pregnancies were observed in 9 patients. CONCLUSIONS FSS may be considered a treatment option in women with stage I EOC, even in those with stage IC(capsule rupture) or more wishing to bear children.

Is there any association between retroperitoneal lymphadenectomy and survival benefit in ovarian clear cell carcinoma patients

BACKGROUND To estimate the survival impact of systemic retroperitoneal lymphadenectomy in patients diagnosed with International Federation of Gynecology and Obstetrics pTI-IIb clear cell carcinoma of the ovary (CCC). PATIENTS AND METHODS Demographic and clinicopathologic data were obtained from the Tokai Ovarian Tumor Study Group between 1986 and 2006. Survival curves were calculated using the Kaplan-Meier method. Differences in survival rates were analyzed using the log-rank test. RESULTS A total of 205 patients had clinical pTI-IIb CCC (median age: 52 years, range: 30-75). One hundred and four (50.7%) patients underwent systemic retroperitoneal lymphadenectomy. Lymphadenectomy was not associated with improved disease-free and overall survival in all patients (P = 0.353 and P = 0.645, respectively). Moreover, lymphadenectomy did not improve the overall survival in those with pTIc CCC (P = 0.433). Similarly, on univariate analysis, age, volume of ascites, preoperative CA 125 values, and regimen of chemotherapy were not significant factors. In addition, there was no significant difference in the ratio of positive lymph node metastases regardless of the completion of lymphadenectomy (P = 0.955). CONCLUSION Our data suggest that patients with pTI-IIb CCC who underwent lymphadenectomy did not show a significant improvement in survival. There was no significant difference in the overall and disease-free survival rates in pTI-IIb CCC patients regardless of the completion of surgical staging lymphadenectomy.

Study of ovarian tumors treated at Nagoya University Hospital, 1965–1988

The relative frequency and the age distribution of ovarian tumors (873 primary and 47 secondary tumors) encountered over 23 years at Nagoya University Hospital were examined with respect to histological type and grade of malignancy. Of the primary neoplasms, common epithelial tumors accounted for 56.6%, sex cord-stromal tumors for 7.3%, and germ cell tumors for 39.5%. Among 296 cases with primary malignant neoplasms, common epithelial type accounted for 75.6%, sex cord-stromal tumors for 4.7%, and germ cell tumors for 19.6%. A review of the literature from Western countries indicated that in Japan, the relative frequency of common epithelial tumors is lower but that of germ cell tumors, especially malignant germ cell tumors, is higher. The difference in the incidence of germ cell tumors between Japan and Western countries is not considered significant, and the incidence of common epithelial tumors is considered to be much lower in Japan.

Activator Protein-2 Impairs the Invasion of a Human Extravillous Trophoblast Cell Line

The reduced migration/invasion of extravillous trophoblasts (EVTs) is a key feature of the genesis of preeclampsia. We and others previously reported that transcriptional factors activator protein-2 (AP-2) alpha and AP-2gamma act as suppressors of tumor invasion. The present study examined the expressions of AP-2alpha and AP-2gamma in preeclamptic placenta vs. control placenta and investigated their effect on the function of EVTs. The expressions of AP-2alpha and AP-2gamma were elevated in the preeclamptic placentas in comparison with the gestational age-matched control placentas. Their expressions also increased in EVTs of the preeclamptic placentas. Thereafter, we transfected AP-2alpha or AP-2gamma into human EVT cell line, HTR-8/SVneo. The overexpression of AP-2alpha or AP-2gamma decreased the migratory and invasive abilities in HTR-8/SVneo cells. This was followed by the reduction of protease activated receptor-1 and matrix metalloproteinases and a significant induction of plasminogen activator inhibitor-1 and the tissue inhibitor of metalloproteinase-1. AP-2alpha and AP-2gamma were weakly expressed in the cultured EVTs and HTR-8/SVneo cells, whereas they were induced by TNF-alpha, which increases in preeclamptic placenta and impairs trophoblast invasion. In the presence of TNF-alpha, the invasion of the HTR-8/SVneo cells was partially restored by a blocking of AP-2 induction using small interfering RNA of AP-2. The present data suggest that AP-2 may suppress trophoblast migration and invasion, thus leading to a shallow placentation in preeclampsia.

Immunohistochemical characterisation of extracellular matrix components of salivary gland tumours

Proteoglycans (PGs) were localised immunohistochemically in 52 salivary gland tumours including pleomorphic adenoma, adenoid cystic carcinoma, acinic cell carcinoma, oncocytoma, mucoepidermoid carcinoma, clear cell tumour and Warthin tumour, using antibodies raised against large PG, small PG, chondroitin 4-sulphate PG, chondroitin 6-sulphate PG, heparan sulphate PG and keratan sulphate PG. Large PGs were mainly observed in mucinous materials of extracellular matrix (ECM) and interstitial fibrous element of tumour tissues, while small PGs were located only in hyaline matrix and surrounding fibrous (capsular) connective tissues. Chondroitin 6-sulphate PG was detected in the ECM of pleomorphic adenomas and clear cell carcinomas and in pseudocystic spaces of adenoid cystic carcinomas, but only in vessel walls in non-neoplastic tissues. Keratan sulphate PG was observed to locate in mucinous material of pleomorphic adenomas, acinic cell carcinomas and clear cell carcinomas, but not in the adenoid cystic carcinomas examined, and it was also unobservable in non-neoplastic salivary gland tissues. Heparan sulphate PG was observed on the inner surfaces of true ductal spaces of adenoid cystic carcinomas and on cell surfaces of oncocytoma cells. By HPLC analysis, individual glycosaminoglycans contained in tumour tissues were compared. Chondroitin 6-sulphate PG was very rich in ECM of pleomorphic adenomas and adenoid cystic carcinomas. Pleomorphic adenomas contained relatively more low-sulphated chondroitin sulphate than adenoid cystic carcinomas and other tumours.

Expression of N -acetylglucosaminyltransferase V in endometrial cancer correlates with poor prognosis

N-acetylglucosaminyltransferase V (GnT-V) is an enzyme that catalyses β1–6 branching of N-acetylglucosamine on asparagine-linked oligosaccharides of cell proteins. The present study aimed to investigate GnT-V expression and its prognostic significance in endometrial cancer. N-acetylglucosaminyltransferase V expression was studied by immunohistochemistry in 74 surgically resected endometrial cancers, and the staining intensity was evaluated. High GnT-V expression in tumour cells was found in 43 (58.1%) of the 74 cases, and was positively correlated with advanced patient age, histological grade, and lymph vascular space involvement. Patients with high GnT-V expression had significantly impaired overall survival and progression-free survival (PFS) (P=0.0041 and P=0.0023, respectively) compared to patients with low expression of GnT-V. On multivariate analysis, GnT-V expression was an independent prognostic factor for PFS (P=0.0364). β1–6 branching of asparagine-linked oligosaccharides was also detected in GnT-V-positive endometrial cancer cells by leukoagglutinating phytohaemagglutinin (L4-PHA) staining, and the molecular size of the major glycoproteins recognised by L4-PHA was approximately 60–200 kDa by lectin blot analysis. These results suggested that high GnT-V expression was correlated with an unfavourable clinical outcome, and that GnT-V is involved in the malignant potential of endometrial cancer by increasing the synthesis of β1–6 branching of asparagine-linked oligosaccharides.

Oncolytic viral therapy for human ovarian cancer using a novel replication-competent herpes simplex virus type I mutant in a mouse model

OBJECTIVE Attenuated mutant strains of herpes simplex virus (HSV) have been effectively used for treatment of malignant brain tumors. As HSV-1 can infect and lyse a variety of cell types, other malignancies may also benefit from such treatment. We sought to test the feasibility of HSV-1 mutant-mediated gene therapy treatment of ovarian cancer. METHODS We prepared two attenuated mutant HSV-1 strains. An HSV-1 mutant, hrR3, has replaced the gene encoding ribonucleotide reductase (RR) with the lacZ reporter gene. We also developed a new replication-competent HSV-1 mutant, HR522; this virus, expressing the lacZ reporter gene, induces syncytium formation in infected cells. We compared the efficacy of HR522 with, paclitaxel (Taxol) and hrR3 in the treatment of nude mice harboring human ovarian cancer cells. We also examined the effect of the prodrug ganciclovir (GCV) on the treatment mediated by these HSVs. Survival was evaluated by Kaplan-Meier method and log-rank test. RESULTS The survival of mice treated with a high-titer hrR3 (5 x 10(7) plaque-forming units [PFU]) was significantly prolonged as compared with the group given paclitaxel (P < 0.0001, log-rank test). Although the survival of mice treated with high-titer HR522 (5 x 10(7) PFU) was not significantly prolonged compared with paclitaxel-treated group (P = 0.212, log-rank test), GCV markedly enhanced the efficacy of HR522 administration (P < 0.005, vs paclitaxel, log-rank test). The lacZ gene product, visualized using 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-gal) histochemistry, was detected in HR522-treated tumors in areas also exhibiting apoptotic changes. CONCLUSIONS These findings indicate that the combination of HR522 and GCV possesses significant therapeutic potential for treatment of ovarian cancer. Such viral therapy offers a novel approach to reductions in the dissemination of ovarian cancer.

Ultrastructural localization of aminopeptidase A/angiotensinase and placental leucine aminopeptidase/oxytocinase in chorionic villi of human placenta.

AIMS Membrane-bound aminopeptidases in human placenta are thought to be involved in maintaining homeostasis during pregnancy by metabolizing bioactive peptides such as oxytocin and angiotensin at the interface between the fetus and mother. Because determining the precise localization of these enzymes is required to support this notion, we investigated the ultrastructural localization of two principal enzymes, aminopeptidase A (APA; EC 3.4.11.7)/angiotensinase and placental leucine aminopeptidase (P-LAP; EC 3.4.11.3)/oxytocinase in human first trimester and full-term placenta. METHODS Immunohistochemical analysis using anti-P-LAP and anti-APA antibodies was performed on ultrathin frozen sections of fixed human placental villi. RESULTS Transmission immunoelectron microscopy revealed that both enzymes were expressed on the surface of apical microvilli of syncytiotrophoblast cells and, to a lesser extent, on the basal infoldings. The location of the two enzymes did not vary between the first trimester and full-term placenta sections, while the staining intensities were slightly enhanced in full-term villi. CONCLUSIONS Our observation that P-LAP and APA are present on the microvilli, which is a site of interaction between the mother and fetus, suggests possible involvement of these enzymes in cleaving peptide hormones from the fetus and mother in order to regulate bioactivity.