Clear cell cancer of the ovary

Targeting glutamine dependence through GLS1 inhibition suppresses ARID1A-inactivated clear cell ovarian carcinoma

Alterations in components of the SWI/SNF chromatin-remodeling complex occur in ~20% of all human cancers. For example, ARID1A is mutated in up to 62% of clear cell ovarian carcinoma (OCCC), a disease currently lacking effective therapies. Here we show that ARID1A mutation creates a dependence on glutamine metabolism. SWI/SNF represses glutaminase (GLS1) and ARID1A inactivation upregulates GLS1. ARID1A inactivation increases glutamine utilization and metabolism through the tricarboxylic acid cycle to support aspartate synthesis. Indeed, glutaminase inhibitor CB-839 suppresses the growth of ARID1A mutant, but not wildtype, OCCCs in both orthotopic and patient-derived xenografts. In addition, glutaminase inhibitor CB-839 synergizes with immune checkpoint blockade anti-PDL1 antibody in a genetic OCCC mouse model driven by conditional Arid1a inactivation. Our data indicate that pharmacological inhibition of glutaminase alone or in combination with immune checkpoint blockade represents an effective therapeutic strategy for cancers involving alterations in the SWI/SNF complex such as ARID1A mutations.

Natural killer cell impairment in ovarian clear cell carcinoma

In the present study, we report the analysis of NK cells derived from patients suffering from a rare ovarian cancer histotype of clear cell carcinoma (OCCC) resistant to conventional chemotherapies. We analyzed the phenotype of NK cells derived from peripheral blood (PB) and peritoneal fluid (PF) and evaluated cytotoxic interactions between NK cells and autologous tumor cells (ATC) derived from patients. We provided evidence of impaired degranulation capacity of NK cells derived from patients' PF in the presence of ATC. Analyzing tumor cell ligands recognized by NK cell receptors, we found that ATC are characterized by an HLA class I⁺ phenotype (although the level of HLA-I expression varies among all patients) and by a heterogeneous expression of ligands for activating NK receptors (from normal to decreased expression of some markers). Furthermore, we observed a down-regulation of crucial NK cell activating receptors, primarily DNAX Accessory Molecule-1 (DNAM-1), on tumor-associated NK cells. Based on these results, we propose that this severe lysis defect may be due to both negative interactions between HLA-I-specific inhibitory NK cell receptors/HLA-I molecules and to defective interactions between activating NK receptors and cognate ligands. In conclusion, for the first time, the phenotypic and functional properties of tumor-associated NK cells and their ATC derived from PF of patients with advanced stage of OCCC were characterized. Taken together results indicate altered interactions between NK cells and ATC and shed light on the aggressive mechanisms of this cancer histotype. Further studies on this rare tumor will be helpful to improve and define more effective therapies.

Magnetic resonance imaging for distinguishing ovarian clear cell carcinoma from high-grade serous carcinoma

BACKGROUND

To compare the magnetic resonance imaging (MRI) features of ovarian clear cell carcinoma (CCC) and high-grade serous carcinoma (HGSC), to distinguish CCC from HGSC.

METHODS

MRI features (laterality, shape, size, configuration, papillary projection, signal intensity, enhancement, peritoneal implant, lymphadenopathy, ascites) of 40 tumors in 37 patients with CCC, confirmed by surgery and pathology, were compared with those of 62 tumors in 40 patients with HGSC. Statistical analysis was performed using Mann-Whitney and Fisher's exact tests.

RESULTS

There was a statistically significant difference in the mean maximum diameter, laterality, and FIGO stage (P = 0.002, P < 0.001, P < 0.001, respectively) between CCC and HGSC. Compared to HGSCs, CCCs were more frequently oval (30/40, 75 % vs 12/62, 19 %; P < 0.001), more often cystic (21/40, 53 % vs 8/62, 13 %; P < 0.001) and unilocular (23/29, 79 % vs 7/31, 23 %; P < 0.001), had T1-hyperintense cystic components more often (18/29, 62 % vs 5/29, 17 %; P < 0.001), had larger papillary projections (5.13 ± 0.4 cm vs 2.91 ± 0.3 cm; P < 0.001), were peritoneally implanted less frequently (P = 0.001) and had fewer ascites (P < 0.001).

CONCLUSIONS

CCC typically showed an oval, unilocular cystic mass with large papillary projection and T1-hyperintense cystic components. MRI could be helpful for distinguishing CCC from HGSC.

Molecular classification of high grade endometrioid and clear cell ovarian cancer using TCGA gene expression signatures

BACKGROUND

It is unclear whether the transcriptional subtypes of high grade serous ovarian cancer (HGSOC) apply to high grade clear cell (HGCCOC) or high grade endometrioid ovarian cancer (HGEOC). We aim to delineate transcriptional profiles of HGCCOCs and HGEOCs.

METHODS

We used Agilent microarrays to determine gene expression profiles of 276 well annotated ovarian cancers (OCs) including 37 HGCCOCs and 66 HGEOCs. We excluded low grade OCs as these are known to be distinct molecular entities. We applied the prespecified TCGA and CLOVAR gene signatures using consensus non-negative matrix factorization (NMF).

RESULTS

We confirm the presence of four TCGA transcriptional subtypes and their significant prognostic relevance (p<0.001) across all three histological subtypes (HGSOC, HGCCOC and HGEOCs). However, we also demonstrate that 22/37 (59%) HGCCOCs and 30/67 (45%) HGEOCs form 2 additional separate clusters with distinct gene signatures. Importantly, of the HGCCOC and HGEOCs that clustered separately 62% and 65% were early stage (FIGO I/II), respectively. These finding were confirmed using the reduced CLOVAR gene set for classification where most early stage HGCCOCs and HGEOCs formed a distinct cluster of their own. When restricting the analysis to the four TCGA signatures (ssGSEA or NMF with CLOVAR genes) most early stage HGCCOCs and HGEOC were assigned to the differentiated subtype.

CONCLUSIONS

Using transcriptional profiling the current study suggests that HGCCOCs and HGEOCs of advanced stage group together with HGSOCs. However, HGCCOCs and HGEOCs of early disease stages may have distinct transcriptional signatures similar to those seen in their low grade counterparts.

Serum microRNAs in clear cell carcinoma of the ovary

OBJECTIVE

To identify candidate microRNAs (miRNAs) in the serum of patients with clear cell carcinomas in monitoring disease progression.

MATERIALS AND METHODS

The sera of patients with diagnosed ovarian clear cell carcinoma were collected from 2009 to 2012. Real-time quantitative polymerase chain reaction (PCR) analysis for 270 miRNAs was performed. To offset the potential extraction bias, an equal amount of Caenorhabditis elegans cel-miR-238 was added to each serum specimen before miRNA isolation. miRNA expression was analyzed using the ΔCt method, with cel-miR-238 as controls.

RESULTS

Twenty-one patients with clear cell carcinoma were included. In the discovery phase on four pairs of pre- and postoperative sera, 18 differentially expressed miRNAs were selected from 270 miRNAs. In the validation phase on an independent set of 11 pairs of pre- and postoperative sera, 4 miRNAs (hsa-miR-130a, hsa-miR-138, hsa-miR-187, and hsa-miR-202) were confirmed to be higher in the preoperative sera. In the application phase, hsa-miR-130a remained consistent with the different time points in seven of the 10 patients during clinical follow-up periods. More importantly, in three patients, hsa-miR-130a levels were elevated in early disease recurrences before CA125 was found to be elevated.

CONCLUSION

Hsa-miR-130a may be a useful serum biomarker for detecting recurrence of ovarian clear cell cancer, and warrants further studies.

Clear cell carcinoma of the ovary: multi-slice computed tomography findings

Background

The aim of the study was to describe the multi-slice computed tomography (MSCT) features of clear cell carcinoma (CCC) of the ovary.

Methods

Twenty patients with histology-confirmed CCC of the ovary were retrospectively reviewed. All patients underwent preoperative plain and contrast-enhanced MSCT examinations. Imaging studies were evaluated for the following: (a) location; (b) maximal transverse diameter; (c) shape (round, oval, lobular, or irregular); (d) margin (well defined or ill defined); (e) solid, solid with cystic regions, or cystic; (f) attenuation of the cystic portion; (g) enhancement pattern of the solid portions of the tumor; and (h) the secondary manifestations.

Results

The mean age of the patients was 63 years (range, 44 to 77 years). Tumors were unilateral in 19 patients and bilateral on 1 patient. The maximal transverse diameter of the tumors was relatively larger with a mean diameter of 105.7 mm (range, 45.5 to 260.6 mm). CCCs demonstrated cystic masses with solid regions in 20 lesions. Most lesions were ovoid (15/21), unilocular (16/21), and well-defined (17/21). The CT value of cystic or necrotic portion ranged from 12 to 28 HU (average, 18 HU) on plain image. The solid protrusions of the cystic masses were both few and round with obviously heterogeneous enhancements after contrast.

Conclusions

The ovarian CCCs typically present as a large, well-defined, unilocular cystic mass with solid protrusion and relatively high attenuated cystic or necrotic portions. The solid protrusions are usually both round and few in number with obviously heterogeneous enhancement.

Endogenous androgens and risk of epithelial invasive ovarian cancer by tumor characteristics in the European Prospective Investigation into Cancer and Nutrition

The role of endogenous androgens and sex hormone-binding globulin (SHBG) in ovarian carcinogenesis is poorly understood. Epithelial invasive ovarian cancer (EOC) is a heterogeneous disease and there are no prospective data on endogenous androgens and EOC risk by tumor characteristics (histology, grade, stage) or the dualistic model of ovarian carcinogenesis (i.e. type I vs. type II, leading to less or more aggressive tumors). We conducted a nested case-control study in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort evaluating androgens and SHBG and invasive EOC risk by tumor characteristics. Female participants who provided a blood sample and were not using exogenous hormones at blood donation were eligible (n = 183,257). A total of 565 eligible women developed EOC; two controls (n = 1,097) were matched per case. We used multivariable conditional logistic regression models. We observed no association between androgens, SHBG and EOC overall. A doubling of androstenedione reduced risk of serous carcinomas by 21% (odds ratio (OR)log2 = 0.79, 95% confidence interval [CI] = [0.64-0.97]). Moreover, associations differed for low-grade and high-grade carcinomas, with positive associations for low-grade and inverse associations for high-grade carcinomas (e.g. androstenedione: low grade: ORlog2 = 1.99 [0.98-4.06]; high grade: ORlog2 = 0.75 [0.61-0.93], phet ≤ 0.01), similar associations were observed for type I/II tumors. This is the first prospective study to evaluate androgens, SHBG and EOC risk by tumor characteristics and type I/II status. Our findings support a possible role of androgens in ovarian carcinogenesis. Additional studies exploring this association are needed.

Insulin-like growth factor I and risk of epithelial invasive ovarian cancer by tumour characteristics: results from the EPIC cohort

BACKGROUND

Prospective studies on insulin-like growth factor I (IGF-I) and epithelial ovarian cancer (EOC) risk are inconclusive. Data suggest risk associations vary by tumour characteristics.

METHODS

We conducted a nested case-control study in the European Prospective Investigation into Cancer and Nutrition (EPIC) to evaluate IGF-I concentrations and EOC risk by tumour characteristics (n=565 cases). Multivariable conditional logistic regression models were used to estimate associations.

RESULTS

We observed no association between IGF-I and EOC overall or by tumour characteristics.

CONCLUSIONS

In the largest prospective study to date was no association between IGF-I and EOC risk. Pre-diagnostic serum IGF-I concentrations may not influence EOC risk.

Napsin A is a specific marker for ovarian clear cell adenocarcinoma

Ovarian clear cell adenocarcinoma has a relatively poor prognosis among the ovarian cancer subtypes because of its high chemoresistance. Differential diagnosis of clear cell adenocarcinoma from other ovarian surface epithelial tumors is important for its treatment. Napsin A is a known diagnostic marker for lung adenocarcinoma, and expression of napsin A is reported in a certain portion of thyroid and renal carcinomas. However, napsin A expression in ovarian surface epithelial tumors has not previously been examined. In this study, immunohistochemical analysis revealed that in 71 of 86 ovarian clear cell adenocarcinoma patients (83%) and all of the 13 patients with ovarian clear cell adenofibroma, positive napsin A staining was evident. No expression was observed in 30 serous adenocarcinomas, 11 serous adenomas or borderline tumors, 19 endometrioid adenocarcinomas, 22 mucinous adenomas or borderline tumors, 10 mucinous adenocarcinomas, or 3 yolk sac tumors of the ovary. Furthermore, expression of napsin A was not observed in the normal surface epithelium of the ovary, epithelia of the fallopian tubes, squamous epithelium, endocervical epithelium, or the endometrium of the uterus. Therefore, we propose that napsin A is another sensitive and specific marker for distinguishing ovarian clear cell tumors (especially adenocarcinomas) from other ovarian tumors.

A rare case of synchronous right ovarian clear cell carcinoma and an incidental left ovarian endometrioid carcinoma with immunohistochemical study

Bilateral primary synchronous ovarian neoplasms are rarely encountered in clinical practice. Both ovaries harboring neoplasms is predominantly appreciated as, metastasis from a distant primary or secondary from an advanced primary ovarian neoplasm. However in both the above instances, the histomorphological evaluation is of paramount importance. We encountered an incidental left ovarian, International Federation of Gynecology and Obstetrics grade 2, endometrioid carcinoma in a patient presenting with a right ovarian mass immunohistopathologically proven to be clear cell carcinoma. The documentation of such rare occurrence is of utmost importance for better understanding of histogenesis of ovarian cancers, which may impact management strategies.

Multi-kinase inhibition in ovarian cancer

Sorafenib (Nexavar) is a multi-kinase inhibitor that was developed as an inhibitor of RAF-1, in the ERK1/2 pathway, but which was subsequently shown to inhibit class III tyrosine kinase receptors.¹ More recently regorafenib (Stivarga) has been developed, which is a further fluorinated version of sorafenib with greater bioavailability and similar inhibitory properties against RAF-1/class III RTKs.² Some of the anti-tumor effects of sorafenib have been ascribed to anti-angiogenic actions of this agent on endothelial associated kinases such as VEGFR2. Other effects of sorafenib clearly have to be due to its effects on the inherent biology of the tumor cells themselves. For example, through various mechanisms sorafenib has been shown in the laboratory and the clinic to suppress expression of the protective protein MCL-1.³ Sorafenib has also been linked to inhibition of STAT3, NFκB, and activation of the death receptor CD95.⁴ Sorafenib is routinely dosed daily (400 mg BID) and 7 d after the start of dosing has a C_max of ~21 μM with a nadir at 12 h of ~10 μM, and is a highly protein bound based on in vitro assays.⁵ Despite this in vitro binding data sorafenib has profound in vivo effects on tumor cells in renal carcinoma and hepatocellular carcinoma patients; cells which are not per se addicted to high activity oncogene signals that are targets of sorafenib/regorafenib. Thus the precise stable bioavailable level of sorafenib/regorafenib in patient plasma is not known.