Hitoshi Niikura

Decreased Expression of 14-3-3σ Is Associated with Advanced Disease in Human Epithelial Ovarian Cancer: Its Correlation with Aberrant DNA Methylation

Purpose: In this study, we examined the promoter methylation status and expression of 14-3-3σ and evaluated its clinical significance in epithelial ovarian cancer. Experimental Design: Twelve ovarian cancer cell lines; 2 ovarian surface epithelial cell lines; and 8 normal, 8 benign, 12 borderline, and 102 ovarian cancer tissues were examined. Methylation-specific PCR, quantitative reverse transcription-PCR, and immunohistochemistry were used to evaluate methylation status and expression of 14-3-3σ gene and protein. Results: Among the 12 ovarian cancer cell lines, the presence of a methylated band was detected in seven cell lines. Median values of relative 14-3-3σ gene expression in cancers with methylation (3.27) were significantly lower than those without methylation (16.4; P < 0.001). Treatment of 5-aza-2′-deoxycitidine resulted in the demethylation of the promoter CpG islands and reexpression. All of the normal, benign, and borderline tissues were positive for 14-3-3σ protein, and in ovarian cancer tissues, 73.5% (75 of 102) were positive for 14-3-3σ protein and was almost consistent with methylation status. Negative immunoreactivity of 14-3-3σ was significantly correlated with high age and serous histology, high-grade, advanced-stage residual tumor of >2 cm, high serum CA125, high Ki-67 labeling index, and positive p53 immunoreactivity. 14-3-3σ immunoreactivity was significantly associated with overall survival (P = 0.0058). Conclusions: Our findings suggest that 14-3-3σ is inactivated mainly by aberrant DNA methylation and that it may play an important role in the pathogenesis of epithelial ovarian cancer.

Expression of epidermal growth factor-related proteins and epidermal growth factor receptor in common epithelial ovarian tumors.

SummaryThe biologic significance of epidermal growth factor (EGF)-related proteins and EGF receptor (EGFR) in the development and progression of human ovarian carcinoma was studied in 17 ovarian cystadenomas, 6 mucinous tumors of low malignant potential (LMP), and 25 invasive adenocarcinomas by immunohistochemistry, Results were correlated with clinicopathologic features. We also examined immunoreactivity in five serous adenocarcinomas both before and after cisplatin chemotherapy. Amphiregulin (AR) expression was observed only in mucinous tumors (4 of 8 cystadenomas, 2 of 6 tumors of LMP, and 6 of 10 cystadenocarcinomas), but was not detected in the serous tumors or clear cell adenocarcinomas. EGF, cripto, and EGFR expression was significantly higher in mucinous cystadenocarcinomas than in mucinous cystadenomas or mucinous tumors of LMP. Three of five specimens obtained at a second operation after chemotherapy had more intense or diffuse immunostaining for transforming growth factor α (TGF-α) than the initial specimens did. Coexpression of more than two of the EGF-related proteins or EGFR significantly correlated with increased surgical stage in serous and clear cell carcinoma. AR expression seems to correlate with mucinous differentiation rather than with advanced stages of ovarian tumors. Our results indicate that expression of some EGF-related proteins is greater in certain subtypes of ovarian carcinomas than in their benign counterparts and that coexpression of these proteins is associated with advanced stage in serous and clear cell carcinoma. Increased TGF a expression may also be related to ovarian tumor resistance to cisplatin chemotherapy.

Steroid Sulfatase and Estrogen Sulfotransferase in Human Endometrial Carcinoma

Purpose: Intratumoral metabolism and synthesis of estrogens are considered to play important roles in the pathogenesis and/or development of human endometrial carcinoma. Steroid sulfatase hydrolyzes biologically inactive estrogen sulfates to active estrogens, whereas estrogen sulfotransferase sulfonates estrogens to estrogen sulfates. However, the status of steroid sulfatase and/or estrogen sulfotransferase in human endometrial carcinoma has not been examined. Experimental Design: We first examined the expression of steroid sulfatase and estrogen sulfotransferase in 6 normal endometrium and 76 endometrial carcinoma using immunohistochemistry to elucidate the possible involvement of steroid sulfatase and estrogen sulfotransferase. We then evaluated the enzymatic activity and the semiquantitative analysis of mRNA using reverse transcription-PCR in 21 endometrial carcinomas. We correlated these findings with various clinicopathological parameters including the expression of aromatase, 17β-hydroxysteroid dehydrogenase type 1 and type 2. Results: Steroid sulfatase and estrogen sulfotransferase immunoreactivity was detected in 65 of 76 (86%) and 22 of 76 (29%) cases, respectively. Results of immunoreactivity for steroid sulfatase and estrogen sulfotransferase were significantly correlated with those of enzymatic activity and semiquantitative analysis of mRNA. No significant correlations were detected among the expression of the enzymes involved in intratumoral estrogen metabolism. There was a significant correlation between steroid sulfatase/estrogen sulfotransferase ratio and clinical outcomes of the patients. However, there were no significant differences between steroid sulfatase or estrogen sulfotransferase and estrogen receptor, progesterone receptor, Ki67, histologic grade, or clinical outcomes of the patients. Conclusions: Results of our study demonstrated that increased steroid sulfatase and decreased estrogen sulfotransferase expression in human endometrial carcinomas may result in increased availability of biologically active estrogens and may be related to estrogen-dependent biological features of carcinoma.

Expression of vasohibin as a novel endothelium-derived angiogenesis inhibitor in endometrial cancer

We have previously reported on vasohibin as a novel endothelium‐derived vascular endothelial growth factor (VEGF)–inducible inhibitor of angiogenesis. The aim of our present study was to define the role of vasohibin in endometrioid endometrial adenocarcinoma. We collected 78 sections of endometrial carcinoma for assessment using immunohistochemistry. Twenty‐seven were well differentiated (G1), 25 were moderately differentiated (G2), and 26 were poorly differentiated endometrioid adenocarcinomas (G3). We also included 12 sections of normal cyclic endometria, six of which were in the proliferative phase and six were in the secretory phase. We investigated the expression of vasohibin, and compared it to VEGF receptor‐2 (VEGFR‐2: KDR/flk‐1), CD34, Ki‐67, VEGF‐A, and D2‐40 (as a lymphatic vessel marker). We assessed the ratio of vasohibin‐ and VEGFR‐2‐positive vessels in the stroma of endometrial carcinoma. Immunohistochemical assessment was classified as negative or positive based on staining intensity. Vasohibin was selectively expressed on vascular endothelial cells in both cyclic endometria and endometrial carcinomas. Vasohibin was highly expressed in the normal functional endmetrium of the secretory phase, especially in the spiral artery, and was highly expressed in all grades of endometrioid adenocarcinomas. The stromal endothelial cells in G3 expressed vasohibin and VEGFR‐2 more frequently than these in G1. In endometrioid adenocarcinomas, there was a significant correlation between the expression percentage of vasohibin and that of VEGFR‐2 (P < 0.0001, r2 = 0.591). This is the first study to elucidate the correlation between expression of vasohibin in the stromal endothelial cells and that of VEGFR‐2 in human carcinomas. (Cancer Sci 2008; 99: 914–919)

Expression of epidermal growth factor family proteins and epidermal growth factor receptor in human endometrium

The biological significance of epidermal growth factor (EGF)-related proteins in the development and progression of endometrioid endometrial carcinoma was studied. Expression of EGF-related proteins including EGF, transforming growth factor-alpha (TGF-alpha), cripto (CR), amphiregulin (AR), and EGF receptor (EGFR) were immunohistochemically examined. Results were then correlated with clinicopathologic findings and steroid receptor status in 12 specimens with normal endometrium, 13 with endometrial hyperplasia, and 40 with endometrioid endometrial carcinoma. EGFR, EGF, TGF-alpha, and CR immunoreactivities were observed in 58.3%, 66.7%, 91.6%, and 66.7% of normal endometrial specimens; 100%, 15.4%, 100%, and 30.8% of endometrial hyperplasia specimens; and 67.5%, 32.5%, 65.0%, and 65.0% of endometrial carcinoma specimens, respectively. AR immunoreactivity was not observed in any of the normal, hyperplastic, or neoplastic endometrium. The presence or absence of EGFR or TGF-alpha in endometrial carcinoma correlated with surgical stage, depth of myometrial invasion, and findings from peritoneal washing cytology. EGF expression significantly correlated with the age of the patients and that of CR with surgical stage and peritoneal washing cytological findings. There was a significant correlation between EGFR and TGF-alpha expression, and between EGF and TGF-alpha. Co-expression of EGFR and TGF-alpha, EGFR and CR, and TGF-alpha and CR in carcinoma specimens significantly correlated with advanced surgical stage, deeper myometrial invasion, and positive peritoneal washing cytology. In normal as well as hyperplastic endometrium, endometrial glands immunohistochemically positive for TGF-alpha were generally positive for ER, but in poorly differentiated endometrial carcinoma, cells positive for TGF-alpha tended to be negative for ER. The results of the present study show that among EGF-related proteins, expression of TGF-alpha and CR seem to be associated with the progression of human endometrioid endometrial carcinoma. Additionally, expression of TGF-alpha became increasingly estrogen independent with increasing histological carcinoma grades.

Prognostic value of epidermal growth factor receptor expression in endometrioid endometrial carcinoma

We report here a retrospective study of epidermal growth factor receptor (EGFR) expression in 140 patients with human endometrioid endometrial carcinoma (median period of follow-up, 43.8 months; ranging from 1 to 155 months). Tumor specimens were immunohistochemically examined for the overexpression of EGFR, and the correlation among EGFR status, various clinicopathologic parameters, and prognosis was statistically evaluated. Monoclonal antibody (clone 31 G 7), which recognizes the extracellular domain of the EGFR molecule, was used for immunostaining. Ninety-four of 140 cases were immunohistochemically positive for EGFR (67.1%). The presence or absence of EGFR did not correlate with surgical stage, depth of myometrial invasion (DI), or lymph node involvement, but did correlate with histological grade and patients age. Furthermore, patients with EGFR-positive endometrial carcinoma had a statistically significant shorter length of survival than those with EGFR-negative tumors (P = .018). This trend is more apparent among the patients more than 50 years old (P = .003). When adjusted for surgical stage, DI, and patient age, EGFR status retained prognostic value by multivariate analysis. However, when adjusted for surgical stage, histological grade, DI, and patient age, EGFR status failed to retain prognostic value by multivariate analysis. The results of this study suggest that EGFR expression is correlated with histological grade and greater invasiveness of human endometrioid endometrial carcinoma.

Clinicopathological significance of circadian rhythm-related gene expression levels in patients with epithelial ovarian cancer

Objective. Recent studies implicate circadian genes in the regulation of cell cycle, apoptosis, and cell proliferation at a molecular level. These genesey affect cancer incidence, prognosis, and chemosensitivity. In this study, we measured the expression levels of clock genes and correlated their expression levels with clinicopathological parameters in epithelial ovarian cancer. Methods. The expression levels of core clock genes, per1, per2, per3, cry1, cry2, Bmal1, clock, and CKIɛ were quantified by real‐time quantitative Reverse transcription‐polymerase chain reaction in 83 ovarian cancer tissues and 11 normal ovarian tissues. Results. The expression levels of per1, per2, cry2, clock, CKIɛ in ovarian cancers were significantly lower than those in normal ovaries. In contrast, cry1 expression was highest among the eight examined clock genes, followed by per3 and Bmal1. Cry1 expression was much higher in cancer than that in normal ovaries. Localized circadian gene expression was determined in cancer cells by in situ hybridization analysis. Cry1 expression was significantly reduced in mucinous and grade 3 tumors. Bmal1 expression was also significantly reduced in mucinous adenocarcinomas as compared to other histologies. In a multivariate analysis, the combination of low cry1 expression and low Bmal1 expression was an independent prognostic factor, as well as stage and histological subtype. Conclusions. The antiphase expression of cry1 and Bmal1 may be preserved in ovarian cancers. The combination of cry1 and Bmal1 expression might become a possible prognostic marker in epithelial ovarian cancer.

Expression of EBAG9/RCAS1 is associated with advanced disease in human epithelial ovarian cancer.

Oestrogen receptor-binding fragment associated gene 9, EBAG9, is an oestrogen-responsive gene that was identified in MCF-7 human breast carcinoma cell line. It is identical to RCAS 1, a cancer cell surface antigen possibly involved in immune escape. In the present study, we examined the expression of EBAG9/RCAS1 in human epithelial ovarian cancer using immunohistochemistry, immunoblotting and reverse transcription–polymerase chain reaction (RT–PCR). A total of 90 epithelial ovarian cancer cases were examined immunohistochemically by means of the antibodies for EBAG9 and ERα. The correlation between EBAG9 immunoreactivity and clinicopathological parameters was examined. mRNA expression of EBAG9 and ERα were evaluated by RT–PCR in 22 cases. The expression for EBAG9 and ERα was examined by immunoblotting in 12 ovarian cancer cell lines. EBAG9 immunoreactivity was detected in the surface and cytoplasm of carcinoma cells in 46 out of 90 cases (51.1%). EBAG9 expression was significantly higher in serous histology (P=0.0402) and advanced disease (P=0.0206). No significant relationship was detected between EBAG9 immunoreactivity and overall survival (P=0.689). There was a highly significant correlation between EBAG9 and ER immunoreactivity (P<0.0001). The EBAG9 mRNA was detected in 20 out of 22 cases. In all of the cases that were positive for ERα mRNA, they were also positive for EBAG9 mRNA. Immunoreactive band corresponding to EBAG9 was detected in 11 out of 12 of ovarian cancer cell lines, and was consistent with ERα expression. In conclusion, the wide distribution of EBAG9 and its relation to advanced disease suggest that this protein may play important roles in epithelial ovarian cancer.

Evidence-based guidelines for treatment of cervical cancer in Japan: Japan Society of Gynecologic Oncology (JSGO) 2007 edition

Clinical practice guidelines for gynecologic cancers have been published by the National Comprehensive Cancer Network and the National Cancer Institute. Whereas these guidelines form the basis for the standard of care for gynecologic malignancies in the United States, it has proven difficult to institute them in Japan due to differences in patient characteristics, health-care delivery systems, and insurance programs. Therefore, evidence-based guidelines for treating cervical cancer specifically in Japan have been under development. The Guidelines Formulation Committee and Evaluation Committee were independently established within the Committee for Treatment Guidelines for Cervical Cancer. Opinions from within and outside the Japan Society of Gynecologic Oncology (JSGO) were incorporated into the final draft, and the guidelines were published after approval by the JSGO. These guidelines are composed of ten chapters and comprise three algorithms. Each chapter consists of a clinical question, recommendations, background, objectives, explanations, and references. The objective of these guidelines is to clearly delineate the standard of care for cervical cancer treatment in Japan in order to ensure equitable care for all Japanese women diagnosed with cervical cancer.

Estrogen signaling ability in human endometrial cancer through the cancer-stromal interaction.

The estrogen pathway plays an important role in the etiology of human endometrial carcinoma (EC). We examined whether estrogen biosynthesis in the tumor microenvironment promotes endometrial cancer. To examine the contribution of stromal cells to estrogen signaling in EC, we used reporter cells stably transfected with the estrogen response element (ERE) fused to the destabilized green fluorescent protein (GFP) gene. In this system, the endometrial cancer stromal cells from several patients activated the ERE of cancer cells to a variable extent. The GFP expression level increased when testosterone, a substrate for aromatase, was added. The effect was variably inhibited by aromatase inhibitors (AIs), although the response to AIs varied among patients. These results suggest that GFP expression is driven by estrogen synthesized by aromatase in the endometrial cancer stromal cells. In a second experiment, we constructed an adenovirus reporter vector containing the same construct as the reporter cells described above, and visualized endogenous ERE activity in primary culture cancer cells from 15 EC specimens. The GFP expression levels varied among the cases, and in most primary tissues, ERE activities were strongly inhibited by a pure anti-estrogen, fulvestrant. Interestingly, a minority of primary tissues in endometrial cancer showed ERE activity independent of the estrogen-ER pathway. These results suggest that AI may have some therapeutic value in EC; however, the hormonal microenvironment must be assessed prior to initiating therapy.