Paclitaxel sensitizes homologous recombination-proficient ovarian cancer cells to PARP inhibitor via the CDK1/BRCA1 pathway.

OBJECTIVE: An effective treatment strategy for epithelial ovarian cancer (EOC) with homologous recombination (HR)-proficient (HRP) phenotype has not been established, although poly (ADP-ribose) polymerase inhibitors (PARPi) impact the disease course with HR-deficient (HRD) phenotype. Here, we aimed to clarify the cellular effects of paclitaxel (PTX) on the DNA damage response and the therapeutic application of PTX with PARPi in HRP ovarian cancer. METHODS: Two models with different PTX dosing schedules were established in HRP ovarian cancer OVISE cells. Growth inhibition and HR activity were analyzed in these models with or without PARPi. BRCA1 phosphorylation status was examined in OVISE cells by inhibiting CDK1, which was reduced by PTX treatment. CDK1 expression was evaluated in EOC patients treated with PTX-based neoadjuvant chemotherapy. RESULTS: PTX suppressed CDK1 expression resulting in impaired BRCA1 phosphorylation in OVISE cells. The reduced CDK1 activity by PTX could decrease HR activity in response to DNA damage and therefore increase the sensitivity to PARPi. Immunohistochemistry showed that CDK1 expression was attenuated in samples collected after PTX-based chemotherapy compared to those collected before chemotherapy. The decrease in CDK1 expression was greater with dose-dense PTX schedule than with the conventional PTX schedule. CONCULSIONS: PTX could act synergistically with PARPi in HRP ovarian cancer cells, suggesting that the combination of PTX with PARPi may be a novel treatment strategy extending the utility of PARPi to EOC. Our findings provide cules for future translational clinical trials evaluating the efficacy of PTX in combination with PARPi in HRP ovarian cancer.

Prognostic impact of interleukin-6 expression in stage I ovarian clear cell carcinoma.

OBJECTIVE: Ovarian clear cell carcinoma (OCCC) frequently presents at an early stage. In stage I OCCC, the prognosis differs according to substage. In particular, predictive biomarkers and new treatment strategies are needed for stage IC2/IC3 disease. We investigated tumor biology and prognostic factors for stage I OCCC from a clinicopathological perspective, including the expression of ARID1A and IL-6, which are considered critical for OCCC carcinogenesis. METHODS: A retrospective cohort study of 192 patients with stage I OCCC treated at a single institution was performed. We calculated overall survival (OS) with respect to 12 clinicopathological parameters that included the unique and diverse histological features of OCCC. RESULTS: The estimated 5-year OS rate in patients with all stage I OCCC was 88.9% during a median of 91months of follow-up. The multivariate analysis indicated that substage classification and IL-6 expression status were associated with poor OS (p=0.010 and p=0.027, respectively). Loss of ARID1A expression had no impact on survival; however, it was associated with substage (p=0.001), capsule rupture status (p=0.011), and ascites cytology (p=0.016). No clear association was found between ARID1A and IL-6 expressions. Histological findings, including the presence of endometriosis, adenofibroma, architectural pattern, and tumor cell type, showed no prognostic effects. CONCLUSIONS: Both substage classification and IL-6 expression status may be independent prognostic factors in stage I OCCC. Therefore, IL-6 molecular stratification may be crucial in optimizing therapeutic strategies for early stage OCCC to improve survival.

Antitumor effects of interleukin-6 (IL-6)/interleukin-6 receptor (IL-6R) signaling pathway inhibition in clear cell carcinoma of the ovary.

Among epithelial ovarian cancers, clear cell carcinoma of the ovary (CCC) has unique clinical and molecular characteristics that include chemoresistance resulting in poor prognosis. It was shown that CCC recently was characterized by specific upregulation of the IL-6/IL-6R-signal transducer and activator of transcription 3 (Stat3) signaling pathway. In this study, we aim to clarify whether IL-6/IL-6R mediated signaling pathway could have clinical relations with CCC and to evaluate inhibitory effects of the pathway on CCC carcinogenesis. A total of 84 CCC cases collected from primary surgical specimens were evaluated by the immunohistochemical analysis for IL-6R and phosphorylated Stat3 (pStat3), and we found that high IL-6R expression correlated with poor patient survival both by the univariate and multivariate analyses, suggesting that IL-6/IL-6R signaling pathway could be implicated in the progression of CCC. We further investigated the effects of IL-6/IL-6R mediated signaling pathway inhibition either by IL-6R small interfering RNA (siRNA) approach or humanized anti-human IL-6R antibody (tocilizumab) in CCC. Inhibition of endogenous IL-6R including tocilizumab in CCC cells did reduce cell invasion ability and restored their response to cytotoxic reagent. These data suggest that IL-6/IL-6R signaling pathway could act on CCC cells to enhance invasion and chemoresistance and, therefore, targeting IL-6/IL-6R mediated signaling pathway could be a promising therapeutic strategy for CCC.

MicroRNA-21 is a candidate driver gene for 17q23-25 amplification in ovarian clear cell carcinoma.

BACKGROUND: Epithelial ovarian cancer (EOC) is the most common cause of gynecological malignancy-related mortality. Ovarian clear cell carcinoma (CCC) has unique clinical characteristics and behaviors that differ from other histological types of EOC, including a frequent association with endometriosis and a highly chemoresistant nature, resulting in poor prognosis. However, factors underlying its malignant behavior are still poorly understood. Aberrant expression of microRNAs has been shown to be involved in oncogenesis, and microRNA-21 (miR-21) is frequently overexpressed in many types of cancers. The aim of this study was to investigate the role of miR-21 in 17q23-25 amplification associated with CCC oncogenesis. METHODS: We identified 17q23-25 copy number aberrations among 28 primary CCC tumors by using a comparative genomic hybridization method. Next, we measured expression levels of the candidate target genes, miR-21 and PPM1D, for 17q23-25 amplification by real-time RT-PCR analysis and compared those data with copy number status and clinicopathological features. In addition, immunohistochemical analysis of PTEN (a potential target of miR-21) was performed using the same primary CCC cases. We investigated the biological significance of miR-21 overexpression in CCC using a loss-of-function antisense approach. RESULTS: 17q23-25 amplification with both miR-21 overexpression and PTEN protein loss was detected in 4/28 CCC cases (14.2%). The patients with 17q23-25 amplification had significantly shorter progression-free and overall survival than those without 17q23-25 amplification (log-rank test: p = 0.0496; p = 0.0469, respectively). A significant correlation was observed between miR-21 overexpression and endometriosis. Both PTEN mRNA and PTEN protein expression were increased by miR-21 knockdown in CCC cells. We also confirmed that miR-21 directly bound to the 3'-untranslated region of PTEN mRNA using a dual-luciferase reporter assay. CONCLUSIONS: MiR-21 is a possible driver gene other than PPM1D for 17q23-25 amplification in CCC. Aberrant expression of miR-21 by chromosomal amplification might play an important role in CCC carcinogenesis through the regulation of the PTEN tumor suppressor gene.

Bevacizumab increases the sensitivity of olaparib to homologous recombination-proficient ovarian cancer by suppressing CRY1 via PI3K/AKT pathway.

PARP inhibitors have changed the management of advanced high-grade epithelial ovarian cancer (EOC), especially homologous recombinant (HR)-deficient advanced high-grade EOC. However, the effect of PARP inhibitors on HR-proficient (HRP) EOC is limited. Thus, new therapeutic strategy for HRP EOC is desired. In recent clinical study, the combination of PARP inhibitors with anti-angiogenic agents improved therapeutic efficacy, even in HRP cases. These data suggested that anti-angiogenic agents might potentiate the response to PARP inhibitors in EOC cells. Here, we demonstrated that anti-angiogenic agents, bevacizumab and cediranib, increased the sensitivity of olaparib in HRP EOC cells by suppressing HR activity. Most of the γ-H2AX foci were co-localized with RAD51 foci in control cells. However, most of the RAD51 were decreased in the bevacizumab-treated cells. RNA sequencing showed that bevacizumab decreased the expression of CRY1 under DNA damage stress. CRY1 is one of the transcriptional coregulators associated with circadian rhythm and has recently been reported to regulate the expression of genes required for HR in cancer cells. We found that the anti-angiogenic agents suppressed the increase of CRY1 expression by inhibiting VEGF/VEGFR/PI3K pathway. The suppression of CRY1 expression resulted in decrease of HR activity. In addition, CRY1 inhibition also sensitized EOC cells to olaparib. These data suggested that anti-angiogenic agents and CRY1 inhibitors will be the promising candidate in the combination therapy with PARP inhibitors in HR-proficient EOC.

Pilot study of CD147 protein expression in epithelial ovarian cancer using monoclonal antibody 12C3.

AIM: CD147 is a membrane glycoprotein that is expressed in various cancer cells and is involved in tumor invasion and metastasis by inducing stromal fibroblastic cells to produce matrix metalloproteinases. This study was carried out to evaluate the correlation between CD147 expression and various clinicopathologic parameters, including histological grade and prognosis in a small sample set of human ovarian cancer patients. MATERIAL AND METHODS: Paraffin-embedded surgical tissue samples from 25 patients with ovarian serous and endometrioid adenocarcinoma were stained with anti-CD147 antibody (monoclonal antibody 12C3: MoAb 12C3) for immunohistochemical analysis. RESULTS: CD147 protein was expressed in 84.0% (21 of 25 cases) of cancerous lesions, but not in normal lesions. CD147 expression by ovarian cancer cells was inversely correlated with overall survival. There was no correlation between CD147 expression and histological grade. CONCLUSIONS: These results suggest that measurement of CD147 expression may enhance the understanding of the pathophysiology of epithelial ovarian cancer.

Low intrinsic running capacity is associated with reduced skeletal muscle substrate oxidation and lower mitochondrial content in white skeletal muscle.

Chronic metabolic diseases develop from the complex interaction of environmental and genetic factors, although the extent to which each contributes to these disorders is unknown. Here, we test the hypothesis that artificial selection for low intrinsic aerobic running capacity is associated with reduced skeletal muscle metabolism and impaired metabolic health. Rat models for low- (LCR) and high- (HCR) intrinsic running capacity were derived from genetically heterogeneous N:NIH stock for 20 generations. Artificial selection produced a 530% difference in running capacity between LCR/HCR, which was associated with significant functional differences in glucose and lipid handling by skeletal muscle, as assessed by hindlimb perfusion. LCR had reduced rates of skeletal muscle glucose uptake (∼30%; P = 0.04), glucose oxidation (∼50%; P = 0.04), and lipid oxidation (∼40%; P = 0.02). Artificial selection for low aerobic capacity was also linked with reduced molecular signaling, decreased muscle glycogen, and triglyceride storage, and a lower mitochondrial content in skeletal muscle, with the most profound changes to these parameters evident in white rather than red muscle. We show that a low intrinsic aerobic running capacity confers reduced insulin sensitivity in skeletal muscle and is associated with impaired markers of metabolic health compared with high intrinsic running capacity. Furthermore, selection for high running capacity, in the absence of exercise training, endows increased skeletal muscle insulin sensitivity and oxidative capacity in specifically white muscle rather than red muscle. These data provide evidence that differences in white muscle may have a role in the divergent aerobic capacity observed in this generation of LCR/HCR.

Short-term serum deprivation confers sensitivity to taxanes in platinum-resistant human ovarian cancer cells.

BACKGROUND: Based on the evidences showing that serum deprivation provokes apoptosis in a variety of cells, we have investigated the effect of serum deprivation on drug sensitivity. METHODS: After human ovarian cancer cells were preincubated in 0.5 % serum containing medium for 12 hours, cellular drug sensitivities were determined by colony-forming assay. RESULTS: Serum deprivation treatment resulted in significant increase in paclitaxel sensitivity by factors of mean ± SD, 148.6 ± 28.1 and 10.1 ± 1.0 (n = 3; P < 0.001) fold in platinum-resistant C13 and CP70 cells, respectively. Similarly, serum deprivation induced significant docetaxel sensitivity in these cell lines. However, no enhancement effect of serum deprivation was observed in platinum-sensitive 2008 and A2780 cells. Serum deprivation did not have any effect on the sensitivities to cisplatin, vincristin, and doxorubicin in all of these cells. More than 7-fold increase of apoptotic cells were observed in C13 or CP70 cells when they were treated by serum deprivation followed by paclitaxel compared with the treatment of either serum deprivation or paclitaxel alone. Confocal laser microscopy using rhodamine 123 and flow cytometric analysis with 3,3'-dihexyloxacarbocyanine iodide revealed that serum deprivation decreased mitochondrial membrane potential in C13 or CP70 cells, whereas no change was observed in 2008 and A2780 cells. This indicates that serum deprivation induced depolarization specifically in platinum-resistant cells. Electron microscopy revealed that serum deprivation caused regeneration of mitochondrial matrix structure in C13 or CP70 cells where mitochondria were usually destructed and disappeared. DISCUSSIONS: These results indicate that serum deprivation confers taxane hypersensitivity specifically in platinum-resistant cells by recovering their impaired mitochondrial functions. The evidence might be clinically beneficial for the development of new chemotherapeutic technology, particularly for the patients with platinum-resistant ovarian cancer.

Interleukin-6 as an enhancer of anti-angiogenic therapy for ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) is a subtype of epithelial ovarian cancer (EOC) that is associated with elevated interleukin-6 (IL-6) expression, resistance to chemotherapy, and increased mortality. Although bevacizumab (Bev) is a widely used anti-angiogenic agent for EOC, the efficacy of Bev and the role of IL-6 in modulating angiogenesis in OCCC are unknown. We performed tube formation assays using human umbilical vein endothelial cells (HUVEC) cultured in OCCC cell-conditioned medium and using cells directly co-cultured with OCCC cells. We observed that IL-6 inhibition significantly mitigated the ability of Bev to impede tube formation in both cases. Furthermore, IL-6 blockade disrupted the anti-angiogenic efficacy of Bev and its concomitant anti-tumor activity. In addition, IL-6 inhibition resulted in a significant increase in angiopoietin-1 (Ang1) secretion and decreased vascular endothelial growth factor (VEGF) expression. Clinical specimens also exhibited this reciprocal relationship between IL-6 and Ang1 expression. Finally, depletion of Ang1 abrogated the effects of IL-6 inhibition on Bev activity, demonstrating that IL-6 supports the anti-angiogenic activity of Bev by suppressing Ang1 expression and promoting dependence on VEGF for angiogenesis. Altogether, our data suggest that OCCC tumors with high IL-6 levels are candidates for Bev therapy.

Mesenchymal to epithelial transition in the human ovarian surface epithelium focusing on inclusion cysts.

Most ovarian cancers arise from the mesothelial surface lining of the ovaries or from invaginations of this lining into the superficial ovarian cortex that form cortical inclusion cysts. Thus, these cysts are thought to be precursor lesions of ovarian carcinoma. Epithelial-mesenchymal transition, which is a transcriptional program for inducing maintenance of the mesenchymal phenotype, acts in tumor progression and metastasis. Little is known about the mechanisms involved in mesenchymal-epithelial transition (MET). We aimed to characterize the human ovarian surface epithelium (OSE) and inclusion cysts by immunohistochemical analysis to examine whether MET occurs during inclusion cyst formation in the OSE. We used specimens from 9 endometrial cancer patients who had undergone hysterectomy and bilateral salpingo-oophorectomy. Immunohistochemical analysis was performed in 10 normal ovaries containing 92 inclusion cysts and in 4 normal tubes to examine the expression of antigen markers including calretinin, podoplanin, D2-40, thrombomodulin, HBME-1, vimentin, EMA, WT1, CA125, MOC31, TAG-72, Ber-EP4 and E-cadherin. The positive staining rates for mesothelial markers in normal OSE were 100% (10/10) for calretinin, 80% (8/10) for podoplanin, 80% (8/10) for D2-40, 70% (7/10) for thrombomodulin, 100% (10/10) for HBME-1, 100% (10/10) for vimentin. The positive staining rates for epithelial markers in tubal epithelium were 100% (4/4) for HBME-1, 100% (4/4) for vimentin, 100% (4/4) for EMA, 75% (3/4) for TAG-72, 100% (4/4) for Ber-EP4. Inclusion cysts showed positive staining for both markers with an incidence of 51% (47/92) for HBME-1, 44% (41/92) for vimentin, 65% (60/92) for TAG-72, 88% (81/92) for Ber-EP4. The OSE showed the characteristics of both mesenchymal and epithelium cells. In contrast, inclusion cysts gained epithelial characteristics, but lost mesenchymal characteristics. These findings support that MET occurs during the inclusion cyst formation from OSE.

Establishment of an immortalized human extravillous trophoblast cell line by retroviral infection of E6/E7/hTERT and its transcriptional profile during hypoxia and reoxygenation.

Investigation into the function of human trophoblasts has been largely restricted by a lack of suitable cell models. We aimed to produce normal human trophoblast cell lines with a long lifespan and to provide an ideal in vitro cell model. Primary human trophoblast cells were derived from a placenta that had undergone elective abortion at the 7th week of gestation. The cells were immortalized by infection with retroviral expression vectors containing the type 16 human papillomaviruses E6 and E7 in combination with human telomerase reverse transcriptase (hTERT). Characterization of the cell line was performed by immunocytochemistry using a panel of antibodies, Western blotting, real-time RT-PCR, an invasion assay, gelatin zymography, karyotype analysis and a nude mouse assay. Gene expression profiles under hypoxia (1% O2, 1 h) and subsequent reoxygenation (20% O2, 6 h) were analyzed using cDNA microarray. Immunocytochemistry revealed an extravillous trophoblastic phenotype by positive staining for hCGbeta, cytokeratin 7, HLA-G and CD9. A transwell insert invasion assay showed the invasiveness of this cell line and gelatin zymography detected the secretion of MMP-2 and MMP-9. Karyotype analysis exhibited an almost normal chromosomal number which ranged from 46 to 48 and the cells showed no tumorigenecity in a nude mouse assay. Forty-three genes showing reversible up- or down-regulation during hypoxia were detected using an oligonucleotide array. This newly immortalized cell line, HChEpC1b, is a useful model for the study of extravillous trophoblast function.

MicroRNA-34a/IL-6R pathway as a potential therapeutic target for ovarian high-grade serous carcinoma.

Accumulating evidence has indicated that microRNAs play a critical role in the pathogenesis of human cancers. microRNA-34a (miR-34a) has been shown to be a key regulator of tumor suppression by targeting several cancer-related signals, including the interleukin-6 receptor (IL-6R)/Signal Transducers and Activator of Transcription 3 (STAT3) signaling pathway. Previously, we determined that miR-34a expression was frequently reduced in high-grade serous carcinoma (HGSC), the major subtype of epithelial ovarian cancer (EOC). Considering that the IL-6R/STAT3 signaling pathway is upregulated and believed to be a potential therapeutic target in EOC, we investigated the biological significance of reduced miR-34a expression in HGSC with regard to IL-6R signaling. Additionally, we evaluated the viability of miR-34a as a therapeutic application for HGSC both in vitro and in vivo. Accordingly, we found that the ectopic expression of miR-34a significantly reduced tumor proliferation and invasion through downregulation of IL-6R expression, suggesting that reduced miR-34a expression might play an important role in the malignant potential of HGSC through upregulation of the IL-6R/STAT3 signaling pathway. Moreover, we demonstrated that replacement of miR-34a reduced tumorigenicity of HGSC in vivo. Therefore, this study may provide the rationale for miR-34a replacement as a promising therapeutic strategy for HGSC.

Application of Artificial Intelligence for Preoperative Diagnostic and Prognostic Prediction in Epithelial Ovarian Cancer Based on Blood Biomarkers.

PURPOSE: We aimed to develop an ovarian cancer-specific predictive framework for clinical stage, histotype, residual tumor burden, and prognosis using machine learning methods based on multiple biomarkers. EXPERIMENTAL DESIGN: Overall, 334 patients with epithelial ovarian cancer (EOC) and 101 patients with benign ovarian tumors were randomly assigned to "training" and "test" cohorts. Seven supervised machine learning classifiers, including Gradient Boosting Machine (GBM), Support Vector Machine, Random Forest (RF), Conditional RF (CRF), Naïve Bayes, Neural Network, and Elastic Net, were used to derive diagnostic and prognostic information from 32 parameters commonly available from pretreatment peripheral blood tests and age. RESULTS: Machine learning techniques were superior to conventional regression-based analyses in predicting multiple clinical parameters pertaining to EOC. Ensemble methods combining weak decision trees, such as GBM, RF, and CRF, showed the best performance in EOC prediction. The values for the highest accuracy and area under the ROC curve (AUC) for segregating EOC from benign ovarian tumors with RF were 92.4% and 0.968, respectively. The highest accuracy and AUC for predicting clinical stages with RF were 69.0% and 0.760, respectively. High-grade serous and mucinous histotypes of EOC could be preoperatively predicted with RF. An ordinal RF classifier could distinguish complete resection from others. Unsupervised clustering analysis identified subgroups among early-stage EOC patients with significantly worse survival. CONCLUSIONS: Machine learning systems can provide critical diagnostic and prognostic prediction for patients with EOC before initial intervention, and the use of predictive algorithms may facilitate personalized treatment options through pretreatment stratification of patients.

Exercise training increases components of the c-Cbl-associated protein/c-Cbl signaling cascade in muscle of obese Zucker rats.

The purpose of this investigation was to determine whether alterations in the c-Cbl-associated protein/c-Cbl pathway and/or p38-mitogen-activated protein kinase (p38 MAP kinase) were associated with improved skeletal muscle insulin responsiveness in exercise-trained obese Zucker rats. Obese Zucker rats ran 5 d/wk on a motorized treadmill for 90 minutes over a 7-week period. Age-matched obese Zucker rats (OB-SED) and their lean littermates (LN-SED) were obtained to serve as nontrained controls. Twenty-four (OB-EX-24 h) or 48 hours (OB-EX-48 h) after the last exercise bout, the trained rats were studied via the hind limb perfusion technique in the presence of insulin. Insulin-stimulated glucose uptake was significantly decreased across the skeletal muscle of OB-SED rats compared with LN-SED, but was normalized in the obese rats by 7 weeks of training. The insulin-stimulated plasma membrane protein concentrations of TC10 and glucose transporter 4 were reduced in the sedentary Zuckers, but both proteins were increased by the training protocol. Training did not increase insulin-stimulated p38 MAP kinase protein concentration, nor did it have an effect on insulin-stimulated p38 MAP kinase phosphorylation at the plasma membrane. These results suggest that skeletal muscle insulin resistance is associated with reduced expression of TC10 and that this deficiency can be corrected with exercise training.

PIK3CA and KRAS mutations in cell free circulating DNA are useful markers for monitoring ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) exhibits distinct phenotypes, such as resistance to chemotherapy, poor prognosis and an association with endometriosis. Biomarkers and imaging techniques currently in use are not sufficient for reliable diagnosis of this tumor or prediction of therapeutic response. It has recently been reported that analysis of somatic mutations in cell-free circulating DNA (cfDNA) released from tumor tissues can be useful for tumor diagnosis. In the present study, we attempted to detect mutations in PIK3CA and KRAS in cfDNA from OCCC patients using droplet digital PCR (ddPCR). Here we show that we were able to specifically detect PIK3CA-H1047R and KRAS-G12D in cfDNA from OCCC patients and monitor their response to therapy. Furthermore, we found that by cleaving wild-type PIK3CA using the CRISPR/Cas9 system, we were able to improve the sensitivity of the ddPCR method and detect cfDNA harboring PIK3CA-H1047R. Our results suggest that detection of mutations in cfDNA by ddPCR would be useful for the diagnosis of OCCC, and for predicting its recurrence.

Increased synthesis of indoleamine-2,3-dioxygenase protein is positively associated with impaired survival in patients with serous-type, but not with other types of, ovarian cancer.

We previously reported that indoleamine-2,3-dioxygenase (IDO) is associated with paclitaxel resistance and that IDO serves as a marker of poor prognosis in ovarian serous adenocarcinomas (SA). In this study, to explore the role of IDO in the development of various histological types of ovarian cancer, we further examined IDO expression not only in SA but also in other types of ovarian cancers. Expression of IDO protein was analyzed by immunohistochemistry for a total of 122 ovarian cancers including 40 SA, 67 clear cell adenocarcinomas (CCA), and 15 endometrioid adenocarcinomas (EA) with informed consent. Among these cases, there were 11 CCA accompanied with endometriosis and 60 cases with lymph node metastasis. We classified the samples into four categories by IDO staining pattern. IDO staining was positive in 57.5% of SA, 49.2% of CCA, and 73.3% of EA, respectively. The Kaplan-Meier survival curve showed a clear relationship between staining score and overall survival for patients with advanced (stages III and IV) SA (n=33) who underwent optimal surgery and paclitaxel-carboplatin (TC) chemotherapy as a first-line regimen. There was no association between IDO staining score and overall survival in the CCA cases. Eight of 11 cases (72.7%) of CCA accompanied by endometriosis presented identical staining patterns of IDO between CCA and endometriosis. In 43 of 60 cases (71.6%) with lymph node metastasis, the staining patterns of IDO showed a correspondence between the primary lesion and metastatic site. These results suggested that the increased synthesis of IDO protein was positively associated with impaired survival only in the serous type of ovarian cancer.

Association of extracellular matrix metalloproteinase inducer in endometrial carcinoma with patient outcomes and clinicopathogenesis using monoclonal antibody 12C3.

Extracellular matrix metalloproteinase inducer (EMMPRIN) is a member of the immunoglobulin superfamily of adhesion molecules and has a role in the activation of several matrix metalloproteinases (MMPs). We evaluated whether EMMPRIN expression is related to tumor progression and patient outcome in human endometrial carcinoma. Paraffin-embedded surgical tissue samples from 112 patients with endometrial carcinoma were stained with anti-EMMPRIN antibody (monoclonal antibody 12C3:MoAb 12C3) for immunohistochemical analysis. EMMPRIN protein was expressed in cancerous lesions with the incidence of 97.3% (109 of 112 cases), but not in normal lesions. The scores determined by the combination of intensity and pattern of EMMPRIN staining in cancer cells correlated significantly with various histopathological risk factors: advanced stage, P=0.001; poorly differentiated carcinoma, P<0.001; lymph node metastasis, P=0.002; and lymphatic vessel infiltration, P=0.027. More importantly, recurrence-free survival was shortened in patients with higher EMMPRIN scores (HR, 3.08; 95% CI, 1.32-7.19; P=0.01). These results suggest that measurement of EMMPRIN expression with simple immunohistochemical staining may enhance the understanding of the pathophysiology of endometrial carcinoma.

Genomic consequences of aberrant DNA repair mechanisms stratify ovarian cancer histotypes.

We studied the whole-genome point mutation and structural variation patterns of 133 tumors (59 high-grade serous (HGSC), 35 clear cell (CCOC), 29 endometrioid (ENOC), and 10 adult granulosa cell (GCT)) as a substrate for class discovery in ovarian cancer. Ab initio clustering of integrated point mutation and structural variation signatures identified seven subgroups both between and within histotypes. Prevalence of foldback inversions identified a prognostically significant HGSC group associated with inferior survival. This finding was recapitulated in two independent cohorts (n = 576 cases), transcending BRCA1 and BRCA2 mutation and gene expression features of HGSC. CCOC cancers grouped according to APOBEC deamination (26%) and age-related mutational signatures (40%). ENOCs were divided by cases with microsatellite instability (28%), with a distinct mismatch-repair mutation signature. Taken together, our work establishes the potency of the somatic genome, reflective of diverse DNA repair deficiencies, to stratify ovarian cancers into distinct biological strata within the major histotypes.

Indoleamine 2,3-dioxygenase serves as a marker of poor prognosis in gene expression profiles of serous ovarian cancer cells.

PURPOSE: We aimed to find key molecules associated with chemoresistance in ovarian cancer using gene expression profiling as a screening tool. EXPERIMENTAL DESIGN: Using two newly established paclitaxel-resistant ovarian cancer cell lines from an original paclitaxel-sensitive cell line and four supersensitive and four refractory surgical ovarian cancer specimens from paclitaxel-based chemotherapy, molecules associated with chemoresistance were screened with gene expression profiling arrays containing 39,000 genes. We further analyzed 44 genes that showed significantly different expressions between paclitaxel-sensitive samples and paclitaxel-resistant samples with permutation tests, which were common in cell lines and patients' tumors. RESULTS: Eight of these genes showed reproducible results with real-time reverse transcription-PCR, of which indoleamine 2,3-dioxygenase gene expression was the most prominent and consistent. Moreover, by immunohistochemical analysis using a total of 24 serous-type ovarian cancer surgical specimens (stage III, n = 21; stage IV, n = 7), excluding samples used for GeneChip analysis, the Kaplan-Meier survival curve showed a clear relationship between indoleamine 2,3-dioxygenase staining patterns and overall survival (log-rank test, P = 0.0001). All patients classified as negative survived without relapse. The 50% survival of patients classified as sporadic, focal, and diffuse was 41, 17, and 11 months, respectively. CONCLUSION: The indoleamine 2,3-dioxygenase screened with the GeneChip was positively associated with paclitaxel resistance and with impaired survival in patients with serous-type ovarian cancer.

MicroRNA Gene Expression Signature Driven by miR-9 Overexpression in Ovarian Clear Cell Carcinoma.

Previous studies have identified microRNA (miRNA) involvement in human cancers. This study aimed to elucidate potential clinical and biological associations of ovarian cancer-related miRNA gene expression profiles in high-grade serous carcinoma (HGSC) and ovarian clear cell carcinoma (OCCC). Accordingly, we investigated 27 patients with ovarian cancer (12 HGSC and 15 OCCC cases) using quantitative real-time reverse transcription polymerase chain reaction to determine the cancer-related miRNA expressions. Gene Cluster 3.0 was used for hierarchical clustering analysis, and differentially expressed miRNAs between HGSC and OCCC were identified by the class comparison analysis using BRB-ArrayTools. An unsupervised hierarchical clustering analysis identified two distinct miRNA expression clusters, with histological subtype-related significant differences in the associations between clusters and clinicopathological features. A comparison of miRNA expression in HGSCs and OCCCs identified five miRNAs (miR-132, miR-9, miR-126, miR-34a, and miR-21), with OCCCs demonstrating a statistically higher expression. Further investigation of the biological significance of miR-9 overexpression in OCCC revealed that miR-9 inhibition reduced the cell invasion ability and upregulated E-cadherin expression. Using a luciferase reporter assay, we further demonstrated the direct binding of miR-9 to E-cadherin. Global cancer-related miRNA expression analysis identified statistically unique profiles that could discriminate ovarian cancer histotypes. In OCCC, miR-9 overexpression may affect pathogenesis by targeting E-cadherin, thereby inducing an epithelial-mesenchymal transition. Therefore, miR-9 may be a promising therapeutic target strategy for OCCC.