Ovarian Clear Cell Carcinoma Tumors Research Articles

Spatial profiling of ovarian clear cell carcinoma (OCCC) and identification of immune-hot features.

e17543 Background: OCCC is an ovarian cancer subtype with high incidence in Asia. Despite its frequent occurrence as an early-stage disease, optimal therapeutic options for high-risk patients are limited. Recently, immune-hot features have been proposed as an indicator for poor prognosis for early-stage OCCC. Specific patterns of intra-tumoral heterogeneity (ITH) associated with these immune-hot features have yet to be defined. Methods: Formalin-fixed paraffine embedded (FFPE) tumor sections from 10 early-stage primary OCCC patients were included. Digital Spatial Profiling (DSP) of 18 protein targets from the Human Protein Core Panel was conducted by using the nanoString GeoMx system to profile selected regions of interest (ROIs) based on the reference H&E staining morphology. Areas of illumination (AOIs) were defined according to ROI segmentation by the fluorescence signals of pan-cytokeratin (PanCK), CD45, or DNA. The digital signals were quantified by the nanoString nCounter system. Results: Unsupervised hierarchical clustering of 252 AOIs from 229 ROIs showed 5 distinct clusters. PanCK+ AOIs distributed in 5 clusters were found to express combinations of markers suggestive of immune mimicry: granzyme B (GZMB) high epithelial cells (C1-a), immune signal high epithelial cells (C1-b), immune-like cells (C1-c), fibronectin-high epithelial cells (C2-a), and signal-cold epithelial cells (C2-b). CD45+ AOIs were mostly clustered in C1-c. Tumor cells with C1-c and C2-a features were associated with recurrence while those in C1-a were associated with no recurrence (Chi-square p=2.8E-04). Tumor infiltrating immune cells (TIIs), which were found to be more enriched of the macrophage lineage (stronger CD68 expression, p=4.5E-03), were associated with recurrence (66.7% in recurrence vs 14.3% in no recurrence, Chi-Square p=0.098). TIIs appeared in PanCK segments of C1-b and C1-c with higher frequencies (45% in C1-b, 25% in C1-c, Chi-square p=0.046) and in PanCK segments of C1-a with extremely low frequency (0%). Correlating with morphology, tumors with recurrence showed higher frequency of papillary pattern (54.7%, Chi-Square p=1.01E-04) and lower frequency of tubulocystic pattern (18.9%, Chi-Square p=7.21E-03). Plus, TIIs were found with high frequency in ROIs with papillary pattern (65.2%, Chi-Square p=4.99E-04) and low frequency in ROIs with tubulocystic pattern (8.7%, Chi-Square p=6.43E-03). Papillary ROIs, which showed macrophage lineage immune mimicry, high CD68 intensity and low PanCK intensity, were found to have very low frequency of PanCK segments of C1-a (6.2%, Chi-Square p=1.26E-04), but extremely high frequency (100%) of PanCK segments of C1-c. Conclusions: Spatial profiling of early-stage OCCC tumors revealed immune-hot tumor features associated with recurrence. These features included immune mimicry of tumor cells, the presence of TIIs, and a papillary pattern in morphology.

Frequent PIK3CA mutations in eutopic endometrium of patients with ovarian clear cell carcinoma

Recent studies have reported cancer-associated mutations in normal endometrium. Mutations in eutopic endometrium may lead to endometriosis and endometriosis-associated ovarian cancer. We investigated PIK3CA mutations (PIK3CAm) for three hotspots (E542K, E545K, H1047R) in eutopic endometrium in patients with ovarian cancer and endometriosis from formalin-fixed paraffin-embedded specimens by laser-capture microdissection and droplet digital PCR. The presence of PIK3CAm in eutopic endometrial glands with mutant allele frequency ≥ 15% were as follows: ovarian clear cell carcinoma (OCCC) with PIK3CAm in tumors, 20/300 hotspots in 11/14 cases; OCCC without PIK3CAm, 42/78 hotspots in 11/12 cases; high-grade serous ovarian carcinoma, 8/45 hotspots in 3/5 cases; and endometriotic cysts, 5/63 hotspots in 5/6 cases. These rates were more frequent than in noncancer nonendometriosis controls (7/309 hotspots in 5/17 cases). In OCCC without PIK3CAm, 7/12 (58%) cases showed multiple hotspot mutations in the same eutopic endometrial glands. In 3/54 (5.6%) cases, PIK3CAm was found in eutopic endometrial stroma. Multisampling of the OCCC tumors with PIK3CAm showed intratumor heterogeneity in three of eight cases. In two cases, PIK3CAm was detected in the stromal component of the tumor. Homogenous PIK3CAm in the epithelial component of the tumor matched the mutation in eutopic endometrial glands in only one case. Eutopic endometrial glands in ovarian cancer and endometriosis show high frequency of PIK3CAm that is not consistent with tumors, and multiple hotspot mutations are often found in the same glands. While the mutations identified in eutopic endometrium may not be driver mutations in the patient's cancer, these are still driver mutations but this specific clone has not undergone the requisite steps for the development of cancer.

Oral recombinant methioninase combined with paclitaxel arrests recalcitrant ovarian clear cell carcinoma growth in a patient-derived orthotopic xenograft (PDOX) nude-mouse model.

Advanced ovarian clear cell carcinoma (OCCC) is a recalcitrant disease, often resistant to the first-line platinum-based therapy. Using a novel patient-derived orthotopic xenograft (PDOX) nude-mouse model of OCCC, we tested whether oral-recombinant methioninase (o-rMETase) could enhance the efficacy of paclitaxel (PTX). The OCCC PDOX model was established and passaged in nude mice. The OCCC PDOX models were randomized into 5 groups. G1: untreated control; G2: paclitaxel (PTX) (20mg/kg, intraperitoneal (i.p.) injection, weekly); G3: o-rMETase (100 units, oral, daily); G4: PTX (20mg/kg, i.p. injection, weekly) + carboplatinum (CBDCA) (40mg/kg, i.p. injection weekly); G5: PTX (20mg/kg, i.p. injection, weekly) + o-rMETase (100 units, oral, daily). The treatment period was 2weeks. The combination of PTX and o-rMETase arrested OCCC tumor growth (relative tumor volume: 1.09 ± 0.63 (mean ± SD)) compared with the untreated control (relative tumor volume: 3.92 ± 1.04 (mean ± SD)) (p < 0.0001). There was no significant difference in relative tumor volume between PTX plus o-rMETase and PTX plus CBDCA (relative tumor volume: 1.39 ± 0.37 (mean ± SD)) (p = 0.93). PTX plus o-rMETase arrested the OCCC tumor growth. o-rMETase is readily administered and can greatly enhance first-line therapy of a recalcitrant cancer. The novel and effective treatment strategy in the present report has future clinical potential for patients with OCCC, especially for patients who cannot well tolerate platinum-based therapy.

An immature inhibin-α-expressing subpopulation of ovarian clear cell carcinoma cells is related to an unfavorable prognosis.

Inhibin‐α, a member of transforming growth factor‐β, is elevated in multiple tumors, but its specific roles are poorly understood. Here, we examined the feature of inhibin‐α‐expressing cells in ovarian tumors. Immunohistochemically, inhibin‐α‐expressing tumor cells were detected only in ovarian clear cell carcinoma (OCCC) among various types of ovarian tumors. By comparing the expression of inhibin‐α and Ki‐67, inhibin‐α‐expressing tumor cells were revealed to be less proliferative. When spheroids and chemoresistant cells were derived from OCCC cell lines, the expression level of inhibin‐α was elevated, and that of an immature marker, aldehyde dehydrogenase, was also elevated. In consistent with this, inhibin‐α expression was correlated with other immature markers, such as OCT3/4 and SOX2, and inversely correlated with proliferative marker MKI67 in public database on OCCC. Knockdown of inhibin‐α in OCCC cell decreased chemoresistance. Moreover, prognostic analysis with 69 surgically resected OCCC cases revealed that the increased inhibin‐α expression was an independent unfavorable prognostic factor. These findings suggested that inhibin‐α‐expressing subpopulation of OCCC tumor cells appeared to be less proliferative, immature, and angiogenic and to be related to acceleration of malignant progression.

Tissue factor pathway inhibitor‑2 is specifically expressed in ovarian clear cell carcinoma tissues in the nucleus, cytoplasm and extracellular matrix.

Tissue factor pathway inhibitor-2 (TFPI-2) is a promising candidate as a serum biomarker of ovarian clear cell carcinoma (OCCC), a lethal histological subtype of epithelial ovarian cancer (EOC). TFPI-2 is a secreted serine protease inhibitor that suppresses cancer progression through the inhibition of matrix protease activities. Previous studies have also identified TFPI-2 in the nucleus, and a possible function of nuclear TFPI-2 as a transcriptional repressor of matrix metalloproteinase-2 (MMP-2) was recently demonstrated. We are currently establishing TFPI-2 as a serum biomarker for OCCC patients; however, TFPI-2 expression in OCCC tissues has not been previously investigated. In the present study, we examined TFPI-2 expression and its localization in 11 OCCC cell lines by western blotting and enzyme-linked immune assay. Four cell lines expressed TFPI-2 in the nucleus, cytoplasm and culture plate–attached extracellular fraction, while four other cell lines expressed TFPI-2 only in the extracellular fraction. In the remaining three cell lines, TFPI-2 was not identified in any fraction. The amount of secreted soluble TFPI-2 showed similar trends to that of the plate-attached fraction. We next investigated the expression levels and distribution of TFPI-2 in surgically resected EOC tissues by immunohistochemistry. In 52 of the 77 (67.5%) OCCC tumors, TFPI-2 expression was detected in at least one of the nuclear, cytoplasmic and extracellular matrix fractions. In contrast, we did not identify TFPI-2 in the other EOC subtypes (n=65). TFPI-2-positive expression distinguished CCC from the other EOC tissues with a sensitivity of 67.5% and specificity of 100%. Although the inherent tumor suppressor function, statistical analyses failed to demonstrate correlations between TFPI-2 expression and clinical parameters, including 5-year overall survival, except for the patient age. In conclusion, we identified TFPI-2 expression in the nucleus, cytoplasm and extracellular matrix in OCCC tissues. The high specificity of TFPI-2 may support its use for diagnosis of OCCC in combination with existing markers.

Structure-activity relationship studies and in vitro and in vivo anticancer activity of novel 3-aroyl-1,4-diarylpyrroles against solid tumors and hematological malignancies

Novel 3-aroyl-1,4-diarylpyrrole derivatives were synthesized to explore structure-activity relationships at the phenyls at positions 1 and 4 of the pyrrole. The presence of amino phenyl rings at positions 1 and 4 of the pyrrole ring were found to be a crucial requirement for potent antitumor activity. Several compounds strongly inhibited tubulin assembly through binding to the colchicine site. Compounds 42, 44, 48, 62 and 69 showed antitumor activity with low nanomolar IC50 values in several cancer cell lines. Compound 48 was generally more effective as an inhibitor of glioblastoma, colorectal and urinary bladder cancer cell lines; 69 consistently inhibited CML cell lines and demonstrated superiority in nilotinib and imatinib resistant LAMA84-R and KBM5-T315I cells. In animal models, compound 48 exhibited significant inhibition of the growth of T24 bladder carcinoma and ES-2 ovarian clear cell carcinoma tumors. Compounds 48 and 69 represent robust lead compounds for the design of new broad-spectrum anticancer agents active in different types of solid and hematological tumors.

Identification of potential key genes associated with ovarian clear cell carcinoma.

BackgroundOvarian cancer is the major cause of death from cancer among females worldwide. Ovarian clear cell carcinoma (OCCC) is considered a distinct histopathologic subtype with worse prognosis and resistance to conventional chemotherapy.Materials and methodsWe analyzed five microarray datasets derived from the Gene Expression Omnibus database. GEO2R tool was used to screen out differentially expressed genes (DEGs) between OCCC tumor and normal ovary tissue. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed using the g:Profiler database and Cytoscape. Based on Search Tool for the Retrieval of Interacting Genes, we performed protein–protein interaction (PPI) network analysis on the DEGs. Real-time PCR (RT-PCR) and Western blotting in frozen samples of normal ovary and OCCC were performed to verify the expression difference of hub genes in OCCC patients.ResultsThirty upregulated DEGs and 13 downregulated DEGs were identified by cross referencing. Six were chosen as hub genes with high connectivity degree via PPI network analysis, including two upregulated and four downregulated. RT-PCR and Western blotting results showed significant expression difference of the two upregulated genes, SPP1 and EPCAM, between tumor and normal tissues.ConclusionOur research suggests that SPP1 and EPCAM are overexpressed in OCCC compared with normal ovary tissue. Clinical study of large sample is required to evaluate the value of SPP1 and EPCAM in the precision treatment and prognostic influence on OCCC in the future.

Targeting STAT3 by HO3867 induces apoptosis in ovarian clear cell carcinoma.

Advanced ovarian clear cell carcinoma (OCCC) carries a very poor prognosis in large part secondary to the extremely high rate of resistance to standard platinum and taxane chemotherapy. Signal transducer and activator of transcription 3(STAT3) expression and activation has been shown to regulate tumor progression in various human cancers, though has not been well studied in OCCC. Preliminary work in our lab has demonstrated constitutive activation of STAT3 (pSTAT3Tyr705 or pSTAT3727) in OCCC cell lines as well as human OCCC tumor tissue samples. Significantly, pSTAT3 is expressed in the absence of other forms of activated STAT (pSTAT1, 2, 6). Therefore, this work was planned to investigate the role of STAT3 and examine the efficacy of a novel anti-cancer compound -HO-3867, which is an inhibitor of STAT3, using known OCCC cell lines. Results demonstrate that treatment with HO-3867 decreased expression of pSTAT3 Tyr705 as well pSTAT3 Ser727, while total STAT3 remained constant. STAT3 overexpression increased the migration capability in OVTOKO cells in vitro and led to an increased tumor size when injected in vivo. The inhibitory effect of HO-3867 on cell proliferation and cell survival was accompanied by increased apoptosis, within 24 h post treatment. Treatment with HO-3867 resulted in a decrease in Bcl-2 and increase of cleavage of caspase 3, caspase 7, and PARP, confirming induction of apoptosis after treatment with HO-3867. In addition, HO-3867 significantly inhibited formation of human umbilical vein endothelial cells capillary-like structures and invasion at both 5 and 10 µM concentrations. STAT3 expression plays an important role in the spread of OCCC in vitro as well as in vivo. Thus, we can exploit the STAT3 pathway for targeted drug therapy. Inhibition of pSTAT3 using HO-3867in OCCC cell lines appears to be a promising therapy. This is of utmost importance given the poor response of OCCC to standard chemotherapy regimens.

Abstract 1219: Integrative kinome exome sequencing and copy number profiling of ovarian clear cell carcinoma

Abstract Introduction: High stage ovarian clear cell carcinoma (OCCC) is less responsive to chemotherapy and has a worse prognosis than other ovarian cancer subtypes. The most frequently mutated genes in OCCC have been characterized in recent years. These include deleterious mutations in the tumor suppressor gene ARID1A, epigenetic silencing and deleterious mutations in the PI3K antagonist PTEN as well as activating mutations in the PI3K catalytic subunit PIK3CA. Yet, therapeutic strategies that utilize these genetic aberrations are lacking. In the present study, we aimed to identify and validate new kinase targets in OCCC. Methods: To determine new mutations and copy number gains and losses, kinome sequencing was performed on DNA isolated from tumor samples (n=124) and matched controls (n=47) and high-coverage SNP analysis was implemented for 109 of the collected OCCC tumor samples. Inhibitor sensitivity screening was performed on 17 OCCC cell lines to validate potential kinase targets, following in vivo validation in OCCC patient-derived xenografts (PDX). Results: Mutations in ARID1A, PIK3CA, PTEN, KRAS and TP53 corresponded to frequencies found in literature. Most identified mutations could be designated to the PI3K/Akt/mTOR and MAPK signal transduction pathway, and HER family of receptor tyrosine kinases. The PI3K pathway related genes PIK3R1, ERBB3 and AKT1 were significantly mutated in our dataset and not described in OCCC before. EGFR, ERBB2 and PIK3CA emerged as most frequently amplified kinases. Combining mutations and copy number alterations in these pathways, 91% of all tumors were affected. The highly positive staining of p-S6 (90% of OCCC tumors) indeed suggests high mTORC1/2 activity in these tumors. Inhibitor screening demonstrated subsets of cell lines to be sensitive to EGFR or ERBB2 inhibition. Furthermore, the vast majority of OCCC cell lines was susceptible to inhibition of PI3K and MAPK downstream target mTORC1/2 using AZD8055, which efficacy was further demonstrated in several OCCC PDX models. In contrast, mTORC1 inhibition alone was less effective. Conclusion: Most kinase mutations and copy number alterations in OCCC can be related to PI3K and MAPK pathway activation. In vitro and in vivo data suggest mTORC1/2 inhibition as a novel treatment strategy in OCCC. Combinations of EGFR or ERBB2 inhibition with mTORC1/2 targeted therapy can be envisioned for OCCC tumors with EGFR or ERBB2 alterations. Supported by a grant from the Dutch Cancer Foundation: RUG 2012-5477 Citation Format: J.j. Caumanns, G.b.a Wisman, K Berns, T. Tomar, R.s.n. Fehrmann, R Bernards, A.g.j. Van der Zee, S De Jong. Integrative kinome exome sequencing and copy number profiling of ovarian clear cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1219. doi:10.1158/1538-7445.AM2017-1219

HNF1β drives glutathione (GSH) synthesis underlying intrinsic carboplatin resistance of ovarian clear cell carcinoma (OCCC).

Chemoresistance to platinum-based antineoplastic agents is a consistent feature among ovarian carcinomas; however, whereas high-grade serous carcinoma (OSC) acquires resistance during chemotherapy, ovarian clear cell carcinoma (OCCC) is intrinsically resistant. The main objective of this study was to explore, in vitro and in vivo, if hepatocyte nuclear factor 1β (HNF1β) and glutaminolysis contribute for the resistance of OCCC to carboplatin through the intrinsically increased GSH bioavailability. To disclose the role of HNF1β, experiments were also performed in an OSC cell line, which does not express HNF1β. Metabolic profiles, GSH quantification, HNF1β, and γ-glutamylcysteine ligase catalytic subunit (GCLC) and modifier subunit (GCLM) expression, cell cycle, and death were assessed in ES2 cell line (OCCC) and OVCAR3 cell line (OSC); HNF1β knockdown was performed in ES2 and murine model of subcutaneous and peritoneal OCCC tumors was established to test buthionine sulphoxamine (BSO), as a sensitizer to carboplatin. Glutaminolysis is activated in ES2 and OVCAR3, though ES2 exclusively synthesizes amino acids and GSH. ES2 cells are more resistant to carboplatin than OVCAR3 and the abrogation of GSH production by BSO sensitizes ES2 to carboplatin. HNF1β regulates the expression of GCLC, but not GCLM, and consequently GSH production in ES2. In vivo, BSO prior to carboplatin reduces dramatically subcutaneous tumor size and GSH levels, as well as peritoneal dissemination. Our study discloses HNF1β as the mediator of intrinsic OCCC chemoresistance and sheds a light to re-explore a cancer adjuvant therapeutic approach using BSO to overcome the lack of efficient therapy in OCCC.

Abstract 5335: Discovery and validation of new kinase targets for therapy in ovarian clear cell cancer

Abstract Introduction: Ovarian clear cell carcinoma is less responsive to chemotherapy and has a worse prognosis than other ovarian cancer subtypes. The most frequently mutated genes in ovarian clear cell carcinoma have been characterized in recent years. Mutations include deleterious mutations in the tumor suppressor gene ARID1A, epigenetic silencing and deleterious mutations in the PI3K antagonist PTEN, as well as activating mutations in the PI3K catalytic subunit PIK3CA. Yet, therapeutic strategies that utilize these genetic aberrations are lacking. In the present study, we aimed to identify and validate new kinase targets in ovarian clear cell carcinoma. Methods: To determine new mutations, kinome sequencing (SureSelect Human Kinome Kit, Agilent Technologies) was performed on DNA isolated from tumor samples (n = 124) and matched controls (n = 46) for 571 kinases, 6 PI3K regulatory components and 46 other cancer related genes. In addition, to identify gene copy number gains and losses, high-throughput SNP analysis (HumanOmniExpressExome-8 Illumina SNP array) were analyzed in 109 ovarian clear cell carcinoma tumor samples. Results: Preliminary results revealed mutations in PIK3CA (43.5%), PTEN (6.5%), KRAS (15.3%) and TP53 (11.3%), which correspond to frequencies found in literature. Most mutations were found in genes encoding PI3K/Akt and MAPK signal transduction pathway, DNA repair pathway, and receptor tyrosine kinase signaling pathway components. Mutations in these pathways were present in 75% of ovarian clear cell carcinomas, while 42% of the patients had mutations in ≥ 2 of these pathways. Profiles of copy number gains and losses matched previous studies. Most interestingly, however, we also discovered multiple novel kinase mutations and identified new chromosomal regions of copy number gains and losses. Conclusion: Combining high-throughput SNP analysis and kinome sequencing allowed us to identify novel mutations, copy number gains and losses in kinases and other cancer related genes. Currently we are re-sequencing the most interesting kinase mutations using Sanger sequencing. Subsequent validation of the therapeutic value of new targets will be assessed in vitro using a large ovarian clear cell carcinoma cell line panel followed by in vivo validations. Supported by a grant from the Dutch Cancer Foundation: RUG 2012-5477 Citation Format: Joseph J. Caumanns, Steven de Jong, G. Bea A. Wisman, Pieter Van der Vlies, Roel J.C. Kluin, Lorenza Mittempergher, Katrien Berns, René Bernards, Ate G.J. Van der Zee, The ovarian clear cell cancer consortium. Discovery and validation of new kinase targets for therapy in ovarian clear cell cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5335. doi:10.1158/1538-7445.AM2015-5335

Abstract 5405: Targeting STAT3 as a novel therapy for ovarian clear cell carcinoma

Abstract Objective: Advanced ovarian clear cell carcinoma (OCCC) carries a very poor prognosis in large part secondary to the high rate of resistance to standard platinum and taxane chemotherapy. STAT3 expression and activation has been shown to regulate tumor progression in various human cancers though has not been well studied in OCCC. Preliminary work in our lab has demonstrated constitutive activation of STAT3 (pSTAT3Tyr705 or pSTAT3727) in OCCC cell lines as well as human OCCC tumor tissue samples. Significantly, pSTAT3 is expressed in the absence of other forms of activated STAT (pSTAT1,2,6). Based on our preliminary data, we hypothesized that use of a novel STAT3 inhibitor, HO-3867, would be an effective agent against OCCC cell lines in vitro and in vivo using a novel orthotopic mouse model. Methods: Five OCCC cell lines (JHOC, OVISE, OVTOKO, RMGV, and ES2) were treated with HO-3867, cisplatin, or paclitaxel alone and/or in combination. Protein expression in tumor tissue and cell lines was determined by western blot (WB) and RT PCR was used to analyze RNA expression levels. MTT assay, BrdU assay, ANNEXIN V kit and flow cytometry were used to analyze cell viability, proliferation, apoptosis and cell cycle arrest. We use a novel orthotopic murine model using an ovarian bursal injection which was developed in our laboratory and has demonstrated primary ovarian tumor development and peritoneal carcinomatosis. Results: Treatment with HO-3867 decreased expression of pSTAT3 while total STAT3 remained constant. Treatment with cisplatin or paclitaxel resulted in a relative increase in pSTAT3. The inhibitory effect of HO-3867 on cell proliferation is associated with G2/M phase cell cycle arrest and apoptosis (&amp;gt;45%) within 24 hours of treatment. Treatment with HO-3867 resulted in a decrease in BCL2 and cleavage of caspase 3, caspase 7, and PARP confirming induction of apoptosis after treatment with HO-3867. Treatment with cisplatin or paclitaxel was less effective at decreasing cell viability, reducing proliferation, and inducing apoptosis. In vivo experiments using the orthotopic murine model are ongoing. Conclusion: HO-3867, a novel STAT3 inhibitor, appears to be efficacious against OCCC in vitro as compared to standard chemotherapeutics. Further investigation into this novel therapy is warranted given the generally poor response of OCCC to our standard chemotherapy regimens. Experiments to investigate the efficacy of HO-3867 in OCCC in vivo are underway. Citation Format: Kristin L. Bixel, Uksha Saini, Jack Fowler, Sneja Rajendran, Ross Wanner, Noriomi Matsumura, Kalman Hideg, Ikuo Konishi, David Cohn, Selvendiran Karrupaiyah. Targeting STAT3 as a novel therapy for ovarian clear cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5405. doi:10.1158/1538-7445.AM2015-5405

Global gene expression profiling of a mouse model of ovarian clear cell carcinoma caused by ARID1A and PIK3CA mutations implicates a role for inflammatory cytokine signaling

Ovarian clear-cell carcinoma (OCCC) is an aggressive form of epithelial ovarian cancer (EOC). OCCC represents 5–25% of all EOC incidences and is the second leading cause of death from ovarian cancer (Glasspool and McNeish, 2013) [1]. A recent publication by Chandler et al. reported the first mouse model of OCCC that resembles human OCCC both genetically and histologically by inducing a localized deletion of ARID1A and the expression of the PIK3CAH1047R substitution mutation (Chandler et al., 2015) [2]. We utilized Affymetrix Mouse Gene 2.1 ST arrays for the global gene expression profiling of mouse primary OCCC tumor samples and animal-matched normal ovaries to identify cancer-dependent gene expression. We describe the approach used to generate the differentially expressed genes from the publicly available data deposited at the Gene Expression Omnibus (GEO) database under the accession number GSE57380. These data were used in cross-species comparisons to publically available human OCCC gene expression data and allowed the identification of coordinately regulated genes in both mouse and human OCCC and supportive of a role for inflammatory cytokine signaling in OCCC pathogenesis (Chandler et al., 2015) [2].

Abstract 4615: Key miRNAs and co-targets in patients of OPSC and OCC

Abstract Objectives: To identify the key microRNAs (miRNAs) and their top co-targets in patients of elderly ovarian papillary serous carcinoma (OPSC) patients with advanced stage and ovarian clear cell carcinoma (OCC), for the insight of possible regulation gene and pathway of epithelial ovarian cancer (EOC) prognosis. Methods: The study was opened to patients with primary, previously untreated EOC referred to member institutions. Pathologic diagnosis was confirmed by central review. High-throughput analysis of the miRNA profile in a panel of OCC and OPSC cells was assessed using a microarray platform. The miRNA-targets and possible pathway were predicted by TargetScans, MicroCosm Targets version 5, miRBase and Ingenuity. Finally, the downstream predicated co-target, activating transcription factor 3 (ATF3) was validated by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and immunohistochemical (IHC) assay. Results: Of the 667 miRNAs analyzed from human, we identified 83 as enriched in the OPSC, and 15 in OCC (P&amp;lt;0.01 for all). Seventeen of 667 miRNAs were significantly expressed with at least 3 fold differences in the OPSC versus OCC. The expression of tree miRNAs (miR-30a*, miR-30e*, miR-505*) were most significantly lower in OCC comparing to elderly OPSC patients with advanced stage. ATF3, the top co-target gene of three key miRNAs mentioned above was highly expressed in OCC lesions, and a stronger distribution was shown in protein level of ATF3 by immunohistochemistry in OCC than OPSC lesions. Conclusions: We identified the key miRNAs that differentially expressed in patients of elderly OPSC with advanced stage and OCC tumors, predicted and validated the most popular co-target shared by the key miRNAs, indicating the possible regulation gene and pathway for EOC prognosis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4615. doi:1538-7445.AM2012-4615