Tomokazu Umezu

Possible involvement of TWIST in enhanced peritoneal metastasis of epithelial ovarian carcinoma

Loss of E-cadherin triggers peritoneal dissemination, leading to an adverse prognosis for most patients with epithelial ovarian carcinoma (EOC). Because TWIST mainly regulates the epithelial-to-mesenchymal transition and is one of the E-cadherin repressors, we investigated the possibility that TWIST expression affects peritoneal metastasis of EOC using siRNA technique. In the present study, we showed a correlation between TWIST expression and EOC cellular morphology. Furthermore, we demonstrated that the suppression of TWIST expression in EOC cells (HEY) alters the cellular morphology from a fibroblastic and motile phenotype to an epithelial phenotype, and inhibits the adhesion of these cells to mesothelial monolayers. To investigate the mechanism by which down-regulation of TWIST leads to inhibition of adhesion to mesothelial cells (MCs), expression of adhesion molecules (CD29, CD44 and CD54) were observed. Moreover, matrix metalloproteinase 2 and membrane type 1 matrix metalloproteinase, important markers associated with invasive and metastatic potential, were remarkably reduced. This findings suggests that reduced expression of TWIST suppresses the multistep process of peritoneal dissemination (detachment from the primary lesion, adhesion to MCs and invasion of MCs) and may be a potential therapeutic target for the treatment of this carcinoma.

Long-term survival of young women receiving fertility-sparing surgery for ovarian cancer in comparison with those undergoing radical surgery

Objectives:To compare the clinical outcome of patients with stage I epithelial ovarian cancer (EOC) who received with fertility-sparing surgery (FSS) with those who underwent radical surgery (RS).Methods:After a central pathological review and search of the medical records from multiple institutions, a total of 572 patients were retrospectively evaluated. All patients were divided into three groups: group A {FSS (n=74); age, ⩽40}; groups B and C [RS; age, 40⩾{(B), n=52}; 40<{(C), n=446}].Results:Five-year overall survival (OS) and disease-free survival (DFS) rates of patients in the groups were as follows: group A, 90.8% (OS)/87.9% (DFS); group B, 88.3% (OS)/84.4% (DFS); group C, 90.6% (OS)/85.3% (DFS), respectively (OS, P=0.802; DFS, P=0.765). Additionally, there was no significant difference in OS and DFS among the three groups stratified to stage IA or IC (OS (IA), P=0.387; DFS (IA), P=0.314; OS (IC), P=0.993; DFS (IC), P=0.990, respectively). Furthermore, patients with a grade 1–2 or 3 tumours in the FSS group did not have a poorer prognosis than those in the RS group.Conclusions:Stage I EOC patients treated with FSS showed an acceptable prognosis compared with those who underwent RS.

Taxol Resistance Among the Different Histological Subtypes of Ovarian Cancer May Be Associated With the Expression of Class III β-Tubulin

Summary: The prognostic significance of histology has been well established in epithelial ovarian cancer (EOC). Clear cell and mucinous histologies are especially generally accepted to result in an adverse outcome because of their poor chemotherapy response. Previous reports suggested that class III &bgr;-tubulin induced taxol resistance in association with a reduced effect on microtubule dynamic instability. Thus, this study aimed to evaluate class III &bgr;-tubulin expression and examine whether the protein level of class III &bgr;-tubulin was correlated with the histological difference in chemosensitivity. Class III &bgr;-tubulin expression in EOC tissues (n = 80) was immunohistochemically scored into 4 groups (−, ±, +, ++). High-level (+, ++) class III &bgr;-tubulin expression was detected in 30 of 35 clear cell carcinomas, in 8 of 10 mucinous carcinomas, 5 of 11 endometrioid carcinomas, and 5 of 24 serous carcinomas. Nineteen patients were evaluable for response. In 5 responders, high-level class III &bgr;-tubulin expression was not detected. On the other hand, it was detected in 10 of 14 nonresponders. In some ovarian cancer cell lines, we evaluated class III &bgr;-tubulin expression by Western blot analysis. Class III &bgr;-tubulin expression in nonserous carcinoma tended to be higher than that in serous carcinoma. Taxol-resistant SKOV cells showed high-level class III &bgr;-tubulin expression compared with wild-type SKOV cells. Taxol sensitivity differing among histological subtypes in EOC is associated with the expression of class III &bgr;-tubulin.

Indoleamine 2,3-dioxygenase expression predicts impaired survival of invasive cervical cancer patients treated with radical hysterectomy

OBJECTIVE Indoleamine 2,3-dioxygenase (IDO) is a tryptophan-catabolizing enzyme that induces tolerance to host immune surveillance within the tumor microenvironment. The present study aimed to investigate IDO expression and its prognostic significance in invasive cervical cancer. METHODS Immunohistochemical expression of IDO in tumor tissues and its association with clinicopathological factors and survival were analyzed in 112 stage IB-IIB cervical cancer patients treated with radical hysterectomy and pelvic lymphadenectomy. RESULTS IDO was diffusely expressed in tumor cells in 29 (26%) cases and focally expressed at the invasive front in 29 (26%) cases, while the other 54 (48%) cases were IDO-negative. IDO expression was positively correlated with clinical stage, lymph node metastasis, and lymph-vascular space invasion, but not with histological type. Patients with diffuse IDO expression had significantly reduced overall survival (OS) and disease-free survival (DFS) compared to patients with no IDO expression. The 5-year OS/DFS rates for the IDO-negative, focally positive, and diffusely positive groups were 92.3%/84.9%, 89.5%/75.8%, and 65.5%/51.7%, respectively. When we analyzed patients with stage IB disease alone (n=67), the OS and DFS for the IDO-diffusely positive group were significantly lower than those for the IDO-negative group. In multivariate analysis, diffuse IDO expression was found to be an independent prognostic factor for impaired OS and DFS. CONCLUSIONS Diffuse expression of IDO in the tumor obtained from Stage IB-IIB cervical cancer patients who underwent radical hysterectomy was correlated with an unfavorable clinical outcome. These findings suggest that IDO may be a novel post-operative prognostic indicator for stage IB-IIB cervical cancer.

Expression of CXCR4 indicates poor prognosis in patients with clear cell carcinoma of the ovary

Recent reports have shown that CXCR4 is expressed in various solid tumors and is involved in tumor development and metastasis. We examined the distribution and expression of this molecule in clear cell carcinoma of the ovary to elucidate its clinical significance. Paraffin sections from clear cell carcinoma of the ovary tissues (n = 42) were immunostained with CXCR4 antibody, and the staining intensities were evaluated. The clinicopathologic factors examined were age, FIGO (International Federation of Gynecology and Obstetrics) staging, preoperative value of cancer antigen 125 test, and residual tumor after cytoreductive surgery. Overall survival and progression-free survival were evaluated using the Kaplan-Meier method, and multivariate analysis was completed using Cox proportional hazards analysis. Of the 42 carcinomas, lower level CXCR4 immunoexpression was observed in 21 cases (50.0%) (CXCR4(low) group); and higher level immunoexpression, in 21 cases (50.0%) (CXCR4(high) group). Five-year overall survival was significantly poorer in the CXCR4(high) group than in the CXCR4(low) group (overall survival, CXCR4(low) group [90.2%], CXCR4(high) group [50.3%]; P = .0002). In addition, CXCR4(high) immunoexpression significantly predicted a poorer progression-free survival when compared with lower expression (5-year progression-free survival, CXCR4(low) group [90.5%], CXCR4(high) group [36.2%]; P < .0001). Furthermore, multivariate analyses including the age, preoperative cancer antigen 125 test value, FIGO stage, and CXCR4 expressions revealed that CXCR4(high) expression was an independent prognostic factor for poorer overall survival and progression-free survival of patients with clear cell carcinoma of the ovary (overall survival, P = .0011; progression-free survival, P = .0008, respectively). Our current study suggested that the assessment of CXCR4 immunoreactivity may be a useful prognostic indicator and that CXCR4 may play a critical role in the progression of clear cell carcinoma of the ovary.

Glypican-3 expression predicts poor clinical outcome of patients with early-stage clear cell carcinoma of the ovary

Background Glypican-3 (GPC3), a membrane-bound heparan sulphate proteoglycan, may play a role in promoting cancer cell growth and differentiation. Recent studies reported that GPC3 is overexpressed in clear cell carcinoma (CCC) of the ovary, and not other ovarian histotypes. However, in CCC patients, the relationship between the overexpression of GPC3 and prognosis has not yet been clarified. Aim To evaluate GPC3 expression by immunohistochemistry in CCC. Methods and Results In 52 CCC patients, GPC3 expression was observed in 40.4%. In cases of CCC, no correlations were identified between GPC3 expression and clinicopathological factors, such as age, FIGO stage, CA125 values, peritoneal cytology, ascitic fluid volume and mortality rate, except for the residual tumour size. GPC3 expression was associated with poor progression-free survival in stage I CCC patients. The numbers of Ki-67-stained cells in GPC3-positive areas were lower than those in GPC3-negative areas. GPC3 expression may be associated with a low proliferation rate in CCC cells. In the early stage of CCC, GPC3-expressing patients tended to be resistant to taxane-based treatment. Conclusions Results suggest that the overexpression of GPC3 may be related to the low-level proliferation of tumours; it may be associated with resistance to taxane-based chemotherapy and a poor prognosis in CCC of the ovary.

Diagnostic utility of CD117, CD133, SALL4, OCT4, TCL1 and glypican-3 in malignant germ cell tumors of the ovary

Aim:  Primary ovarian malignant germ cell tumors (OMGCTs) are rare and difficult to diagnose. Immunohistochemistry can help in the diagnosis and development of new management strategies. The aim of this study was to investigate the frequency of CD117, CD133, SALL4, OCT4, TCL1 and glypican‐3 marker expression in OMGCTs.

Postrecurrent oncologic outcome of patients with ovarian clear cell carcinoma.

Objectives To estimate the long-term clinical outcome of patients with recurrent clear cell carcinoma (RCCC) of the ovary in comparison with those with recurrent serous adenocarcinoma (RSAC). Patients and Methods In this study, 113 patients with RCCC and 365 patients with RSAC were analyzed. The pathological slides were evaluated under central pathological review. End points were the overall survival (OS), postrecurrence survival (PRS), and timing of death of mortality cases. Results The 5-year OS and PRS rates of patients with RCCC were 22.5 and 13.2%, respectively. In both OS and PRS, the prognosis of patients with RCCC was significantly poorer than that of the patients with RSAC (OS: P = 0.0007; PRS: P < 0.0001). Moreover, regardless of the status of the residual tumor (RT) at the initial surgery, the OS and PRS of the patients with RCCC were markedly shorter than those with RSAC (RT [−]: OS, P = 0.0005: PRS, P = 0.0002: RT [+]: OS, P < 0.0001: PRS, P < 0.0001). In multivariable analysis, the histological type was a significantly poorer prognostic indicator for OS and PRS (OS [RCCC vs RSAC]: hazard ratio, 2.302: 95% confidence interval, 1.723–3.076; P < 0.0001: PRS [RCCC vs RSAC]; hazard ratio, 2.353: 95% confidence interval, 1.756–3.155; P < 0.0001). Even in the deceased patients (n = 350), the rate of patients with RCCC dying within 12 months of recurrence was higher than that of RSAC (RCCC, 67.8%; RSAC, 40.7%; [P < 0.0001]). Conclusions The long-term clinical outcome of patients with RCCC was extremely poor. We confirmed that RCCC should be investigated as a different malignancy compared with RSAC.

Identification and characterization of cancer stem cells in ovarian yolk sac tumors.

Recent evidence supports the cancer stem cell theory, that is, that malignant tumors arise from cells termed cancer stem cells or tumor‐initiating cells that have the ability to self‐renew and are responsible for maintaining the tumor. Cells with marked tumor‐initiating capacity have recently been identified in a number of solid tumors. CD133 (PROM1, human prominin‐1) has been used as a marker to detect stem cells (progenitor cells) and cancer stem cells (tumor‐initiating cells) in various tissues. Ovarian yolk sac tumors (YSTs) are rare and highly malignant. The present study was designed to evaluate the tumor‐forming ability of CD133+ cells in ovarian YST cell lines and to examine the characteristics of CD133+ cells, such as cell growth and invasiveness. Our data suggest ovarian YST to be maintained by a rare fraction of cancer stem‐like cells that express the cell surface marker CD133. (Cancer Sci 2010)

High expression of N-acetylglucosaminyltransferase IVa promotes invasion of choriocarcinoma.

Background:Gestational trophoblastic diseases (GTDs) are related to trophoblasts, and human chorionic gonadotropin (hCG) is secreted by GTDs as well as normal placentas. However, the asparagine-linked sugar chains on hCG contain abnormal biantennary structures in invasive mole and choriocarcinoma, but not normal pregnancy or hydatidiform mole. N-acetylglucosaminyltransferase-IV (GnT-IV) catalyses β1,4-N-acetylglucosamine branching on asparagine-linked oligosaccharides, which are consistent with the abnormal sugar chain structures on hCG.Methods:We investigated GnT-IVa expression in GTDs and placentas by immunohistochemistry, western blot, and RT–PCR. We assessed the effects of GnT-IVa knockdown in choriocarcinoma cells in vitro and in vivo.Results:The GnT-IVa was highly expressed in trophoblasts of invasive mole and choriocarcinoma, and moderately in extravillous trophoblasts during the first trimester, but not in hydatidiform mole or other normal trophoblasts. The GnT-IVa knockdown in choriocarcinoma cells significantly reduced migration and invasive capacities, and suppressed cellular adhesion to extracellular matrix proteins. The extent of β1,4-N-acetylglucosamine branching on β1 integrin was greatly reduced by GnT-IVa knockdown, although the expression of β1 integrin was not changed. In vivo studies further demonstrated that GnT-IVa knockdown suppressed tumour engraftment and growth.Conclusion:These findings suggest that GnT-IVa is involved in regulating invasion of choriocarcinoma through modifications of the oligosaccharide chains of β1 integrin.