The role of CTNNB1 mutations and matrix metalloproteinases (MMPs) in anti-angiogenesis treatment of endometrial carcinoma.

OBJECTIVE: Treatment options and associated biomarkers for advanced and recurrent disease are limited. Endometrial cancers (ECs) with CTNNB1 exon 3 mutations appear to have preferential response to bevacizumab, an anti-angiogenesis treatment, though the mechanism of action is unknown. We aim to identify mediators of bevacizumab-responsive endometrial cancers. METHODS: We analyzed RNA expression from TCGA and protein expression from CPTAC to identify likely targets for ß-catenin overactivity. We then transiently and stably overexpressed ß-catenin in EC cells to confirm the results suggested by our in silico analysis. We performed corroborative experiments by silencing CTNNB1 in mutated cell lines to demonstrate functional specificity. We implanted transduced cells into xenograft models to study microvessel density. RESULTS: CTNNB1-mutated ECs were associated with increased ß-catenin and MMP7 protein abundance (P < 0.001), but not VEGF-A protein abundance. Overexpressing ß-catenin in EC cells did not increase VEGF-A abundance but did increase expression and secretion of MMP7 (P < 0.03). Silencing CTNNB1 in CTNNB1-mutated cells decreased MMP7 gene expression in EC (P < 0.0001). Microvessel density was not increased. CONCLUSIONS: These data provide a mechanistic understanding for bevacizumab-response in CTNNB1-mutated ECs demonstrated in GOG-86P. We hypothesize that overexpressed and secreted MMP7 potentially digests VEGFR-1, releasing VEGF-A, and increasing its availability. These activities may drive the formation of permeable vessels, which contributes to tumor progression, metastasis, and immune suppression. This mechanism is unique to EC and advocates for further clinical trials evaluating this treatment-related biomarker.

Massively parallel sequencing analysis of mucinous ovarian carcinomas: genomic profiling and differential diagnoses.

OBJECTIVE: Mucinous ovarian cancer (MOC) is a rare type of epithelial ovarian cancer resistant to standard chemotherapy regimens. We sought to characterize the repertoire of somatic mutations in MOCs and to define the contribution of massively parallel sequencing to the classification of tumors diagnosed as primary MOCs. METHODS: Following gynecologic pathology and chart review, DNA samples obtained from primary MOCs and matched normal tissues/blood were subjected to whole-exome (n = 9) or massively parallel sequencing targeting 341 cancer genes (n = 15). Immunohistochemical analysis of estrogen receptor, progesterone receptor, PTEN, ARID1A/BAF250a, and the DNA mismatch (MMR) proteins MSH6 and PMS2 was performed for all cases. Mutational frequencies of MOCs were compared to those of high-grade serous ovarian cancers (HGSOCs) and mucinous tumors from other sites. RESULTS: MOCs were heterogeneous at the genetic level, frequently harboring TP53 (75%) mutations, KRAS (71%) mutations and/or CDKN2A/B homozygous deletions/mutations (33%). Although established criteria for diagnosis were employed, four cases harbored mutational and immunohistochemical profiles similar to those of endometrioid carcinomas, and one case for colorectal or endometrioid carcinoma. Significant differences in the frequencies of KRAS, TP53, CDKN2A, FBXW7, PIK3CA and/or APC mutations between the confirmed primary MOCs (n = 19) and HGSOCs, mucinous gastric and/or mucinous colorectal carcinomas were found, whereas no differences in the 341 genes studied between MOCs and mucinous pancreatic carcinomas were identified. CONCLUSIONS: Our findings suggest that the assessment of mutations affecting TP53, KRAS, PIK3CA, ARID1A and POLE, and DNA MMR protein expression may be used to further aid the diagnosis and treatment decision-making of primary MOC.

Genetic predisposition to bevacizumab-induced hypertension.

OBJECTIVE: Bevacizumab, a monoclonal antibody to VEGF, has shown efficacy in ovarian, cervical and endometrial cancer in addition to several other solid tumors. Serious side effects include hypertension, proteinuria, bowel perforation, and thrombosis. We tested the hypothesis that genetic variation in hypertension-associated genes is associated with bevacizumab-induced hypertension (BIH). METHODS: Patients with solid tumors treated with bevacizumab in combination with other therapy were identified from six clinical trials. Haplotype-tagging (ht) SNPs for 10 candidate genes associated with hypertension were identified through the International Hapmap Project. Germline DNA was genotyped for 103 htSNPs using mass spectrometry. Bevacizumab toxicities were identified from clinical trial reports. Haplotypes were reconstructed from diploid genotyping data and frequencies were compared using standard two-sided statistical tests. RESULTS: The study included 114 patients with breast, lung, ovarian, or other cancers, of whom 38 developed BIH. WNK1, KLKB1, and GRK4 were found to contain single loci associated with BIH. Haplotype analysis of WNK1, KLKB1, and GRK4 identified risk haplotypes in each gene associated with grade 3/4 BIH. A composite risk model was created based on these haplotypes. Patients with the highest risk score were the most likely to develop grade 3/4 BIH (OR=6.45; P=0.005; 95%CI, 1.86-22.39). CONCLUSIONS: We concluded that genetic variation in WNK1, KLKB1, and GRK4 may be associated with BIH. These genes are biologically plausible mediators due to their role in blood pressure control, regulating sodium homeostasis and vascular tone. This preliminary risk model performed better than population-based risk models and when further validated may help risk-stratify patients for BIH prior to initiating therapy.

Concomitant loss of SMARCA2 and SMARCA4 expression in small cell carcinoma of the ovary, hypercalcemic type.

Small cell carcinoma of the ovary, hypercalcemic type is an aggressive tumor generally affecting young women with limited treatment options. Mutations in SMARCA4, a catalytic subunit of the SWI/SNF chromatin remodeling complex, have recently been identified in nearly all small cell carcinoma of the ovary, hypercalcemic type cases and represent a signature molecular feature for this disease. Additional biological dependencies associated with small cell carcinoma of the ovary, hypercalcemic type have not been identified. SMARCA2, another catalytic subunit of the SWI/SNF complex mutually exclusive with SMARCA4, is thought to be post-translationally silenced in various cancer types. We analyzed 10 archival small cell carcinoma of the ovary, hypercalcemic type cases for SMARCA2 protein expression by immunohistochemistry and found that SMARCA2 expression was lost in all but one case. None of the 50 other tumors that primarily or secondarily involved the ovary demonstrated concomitant loss of SMARCA2 and SMARCA4. Deep sequencing revealed that this loss of SMARCA2 expression is not the result of mutational inactivation. In addition, we established a small cell carcinoma of the ovary, hypercalcemic type patient-derived xenograft and confirmed the loss of SMARCA2 in this in vitro model. This patient-derived xenograft model, established from a recurrent tumor, also had unexpected mutational features for this disease, including functional mutations in TP53 and POLE. Taken together, our data suggest that concomitant loss of SMARCA2 and SMARCA4 is another hallmark of small cell carcinoma of the ovary, hypercalcemic type-a finding that offers new opportunities for therapeutic interventions.

Ischemia in tumors induces early and sustained phosphorylation changes in stress kinase pathways but does not affect global protein levels.

Protein abundance and phosphorylation convey important information about pathway activity and molecular pathophysiology in diseases including cancer, providing biological insight, informing drug and diagnostic development, and guiding therapeutic intervention. Analyzed tissues are usually collected without tight regulation or documentation of ischemic time. To evaluate the impact of ischemia, we collected human ovarian tumor and breast cancer xenograft tissue without vascular interruption and performed quantitative proteomics and phosphoproteomics after defined ischemic intervals. Although the global expressed proteome and most of the >25,000 quantified phosphosites were unchanged after 60 min, rapid phosphorylation changes were observed in up to 24% of the phosphoproteome, representing activation of critical cancer pathways related to stress response, transcriptional regulation, and cell death. Both pan-tumor and tissue-specific changes were observed. The demonstrated impact of pre-analytical tissue ischemia on tumor biology mandates caution in interpreting stress-pathway activation in such samples and motivates reexamination of collection protocols for phosphoprotein analysis.

Validated gene targets associated with curatively treated advanced serous ovarian carcinoma.

OBJECTIVES: High-grade serous ovarian cancer (HGSOC) mostly presents at an advanced stage and has a low overall survival rate. However, a subgroup of patients are seemingly cured after standard initial therapy. We hypothesize that the molecular profiles of these patients vary from long-term survivors who recur. METHODS: Patients with advanced HGSOC who underwent primary cytoreductive surgery and platinum-based chemotherapy were identified from The Cancer Genome Atlas (TCGA) and institutional (MSKCC) samples. A curative-intent group was defined by recurrence-free survival of >5years. A long-term recurrent group was composed of patients who recurred but survived >5years. RNA was hybridized to Affymetrix U133A transcription microarrays. The NanoString nCounter gene expression system was used for validation in an independent patient population. RESULTS: In 30 curative and 84 recurrent patients, class comparison identified twice as many differentially expressed probes between the groups than expected by chance alone. TCGA and MSKCC data sets had 19 overlapping genes. Pathway analyses identified over-represented networks that included nuclear factor kappa B (NFkB) transcription and extracellular signal-regulated kinase (ERK) signaling. External validation was performed in an independent population of 28 curative and 38 recurrent patients. Three genes (CYP4B1, CEPT1, CHMP4A) in common between our original data sets remained differentially expressed in the external validation data. CONCLUSIONS: There are distinct transcriptional elements in HGSOC from patients likely to be cured by standard primary therapy. Three genes have withstood rigorous validation and are plausible targets for further study, which may provide insight into molecular features associated with long-term survival and chemotherapy resistance mechanisms.

Clonal relatedness between lobular carcinoma in situ and synchronous malignant lesions.

INTRODUCTION: Lobular carcinoma in situ (LCIS) has been accepted as a marker of risk for the development of invasive breast cancer, yet modern models of breast carcinogenesis include LCIS as a precursor of low-grade carcinomas. We provide evidence favoring a clonal origin for LCIS and synchronous estrogen receptor-positive malignant lesions of the ductal and lobular phenotype. METHODS: Patients with prior LCIS undergoing mastectomy were identified preoperatively from 2003 to 2008. Specimens were widely sampled, and frozen blocks were screened for LCIS and co-existing malignant lesions, and were subject to microdissection. Samples from 65 patients were hybridized to the Affymetrix SNP 6.0 array platform. Cases with both an LCIS sample and an associated ductal carcinoma in situ (DCIS) or invasive tumor sample were evaluated for patterns of somatic copy number changes to assess evidence of clonal relatedness. RESULTS: LCIS was identified in 44 of the cases, and among these a DCIS and/or invasive lesion was also identified in 21 cases. A total of 17 tumor pairs had adequate DNA/array data for analysis, including nine pairs of LCIS/invasive lobular cancer, four pairs of LCIS/DCIS, and four pairs of LCIS/invasive ductal cancer. Overall, seven pairs (41%) were judged to be clonally related; in five (29%) evidence suggested clonality but was equivocal, and five (29%) were considered independent. Clonal pairs were observed with all matched lesion types and low and high histological grades. We also show anecdotal evidence of clonality between a patient-matched triplet of LCIS, DCIS, and invasive ductal cancer. CONCLUSION: Our results support the role of LCIS as a precursor in the development of both high-grade and low-grade ductal and lobular cancers.

Morphologic patterns associated with BRCA1 and BRCA2 genotype in ovarian carcinoma.

This study was undertaken with the hypothesis that certain common morphologic features of ovarian carcinomas are predictably associated with BRCA1 and BRCA2 deficiencies. We selected 43 high-grade serous carcinomas diagnosed at Memorial Sloan-Kettering Cancer Center that were studied as part of The Cancer Genome Atlas pilot project. In addition to 12 randomly selected nonfamilial BRCA-unassociated cases, all 31 Memorial Sloan-Kettering Cancer Center cases with BRCA1 or BRCA2 abnormality were included (n=43). Slides were examined to assess tumor architecture, mitotic index, tumor-infiltrating lymphocytes (TILs), nuclear pleomorphism, necrosis, and involvement of fallopian tube epithelium. Comparing BRCA1-associated cases (BRCA1 germline mutation, n=4, BRCA1 somatic mutation, n=6, BRCA1 promoter methylation, n=13) with unassociated cases (n=12) identified statistically significant differences in morphology. BRCA1-associated high-grade serous carcinomas had more frequent Solid, pseudoEndometrioid, and Transitional cell carcinoma-like morphology (SET features) (P=0.0045), higher mitotic indexes (P=0.012), more TILs (P=0.034), and either geographic or comedo necrosis (P=0.034). BRCA2-associated cases (germline mutation, n=4 and somatic mutation, n=4) tended to show SET features, but they were relatively deficient in TILs and necrosis. Two algorithms incorporating tumor architecture, necrosis, and either mitotic indexes or TILs separated cases that showed 2 of 3 features (BRCA1 associated) from those with 0 of 3 features (BRCA unassociated; P=0.0016 and P=0.0033). A test set comprising 9 BRCA1 germline mutants and 14 high-grade serous carcinoma controls lacking BRCA1 and BRCA2 germline mutation was used to validate the algorithms, with specific emphasis on the ability to detect cases with BRCA1 germline mutation. Best results were obtained with the algorithm that incorporated SET features, necrosis, and mitotic index (P=0.0072; sensitivity of 1.0 (95% CI, 0.66-1.0); specificity of 0.57 (95% CI, 0.29-0.82); positive predictive value of 0.60 (95% CI, 0.32-0.84) and a negative predictive value of 1.0 (95% CI, 0.63-1.0)). These preliminary data indicate potential strong associations between morphology and genotype in high-grade serous carcinomas.

A microRNA survival signature (MiSS) for advanced ovarian cancer.

OBJECTIVES: MicroRNAs (miRNAs) are a class of small non-coding RNAs that negatively regulate gene expression primarily through post-transcriptional modification. We tested the hypothesis that miRNA expression is associated with overall survival in advanced ovarian cancer. METHODS: Cases included newly diagnosed patients with stage III or IV serous ovarian cancer. RNA from a training set of 62 cases was hybridized to an miRNA microarray containing 470 mature human transcripts. Cox Regression was performed to identify miRNAs associated with overall survival. External validation was performed using quantitative RT-PCR miRNA assays in an independent test set of 123 samples. MiRNA targets and associated biologic pathways were predicted in silico. RESULTS: Of all patients, 80% had high-grade, stage IIIC tumors and 64% underwent optimal cytoreduction. The median survival for the entire cohort was 49±4 months. The training set identified 3 miRNAs associated with survival--miR-337, miR-410, and miR-645. An miRNA signature containing miR-410 and miR-645 was most strongly associated with overall survival in the training set (HR=2.96, 95% CI: 1.51-5.78). This miRNA survival signature (MiSS) was validated in the test set (HR=1.71, 95% CI: 1.05-2.78). The MiSS was independent of FIGO stage and surgical debulking. CONCLUSIONS: The data suggest that an MiSS that contains miR-410 and miR-645 is negatively associated with overall survival in advanced serous ovarian cancer. This signature, when further validated, may be useful in individualizing care for the ovarian cancer patient. Pathway analyses identify biologically plausible mechanisms.

CCNE1 amplification among metastatic sites in patients with gynecologic high-grade serous carcinoma.

OBJECTIVE: We sought to characterize the variability of CCNE1 amplification among metastatic sites of CCNE1 amplified high grade serous carcinoma (HGSC) cases to investigate the feasibility of targeting this alteration for therapeutic purposes. METHODS: Patients with CCNE1 amplified HGSC who underwent surgical cytoreduction with metastatic sites were identified from institutional molecular profiling reports and a population of HGSC cases screened using digital droplet PCR (ddPCR). Cases with normal CCNE1 copy number were included as controls. Slides from metastatic sites were cut from formalin-fixed paraffin-embedded tissue blocks, dissected for tumor of > 50% purity, and underwent DNA extraction. CCNE1 copy number was determined by ddPCR. Tumor purity was confirmed with mutant TP53 allele fraction from targeted massively parallel sequencing. RESULTS: Four of 15 patients from an institutional database screened by ddPCR were found to have CCNE1 amplification. Three additional patients were identified from a query of institutional commercial clinical reports. Among these 7 CCNE1 amplified cases (2 uterine, 5 ovarian), 5 showed preservation of CCNE1 amplification (copy number > 5) among all metastatic sites. The remaining 2 cases had multiple metastatic sites without preserved CCNE1 amplification. Non-amplified cases had predominantly normal CCNE1 copy number across metastatic sites. CONCLUSIONS: CCNE1 amplification is an early genomic event in HGSC and is preserved in most metastatic sites suggesting a uniform response to pathway targeting therapies.

Genetically Defined, Syngeneic Organoid Platform for Developing Combination Therapies for Ovarian Cancer.

The paucity of genetically informed, immunocompetent tumor models impedes evaluation of conventional, targeted, and immune therapies. By engineering mouse fallopian tube epithelial organoids using lentiviral gene transduction and/or CRISPR/Cas9 mutagenesis, we generated multiple high-grade serous tubo-ovarian cancer (HGSC) models exhibiting mutational combinations seen in patients with HGSC. Detailed analysis of homologous recombination (HR)-proficient (Trp53-/-;Ccne1OE;Akt2OE;KrasOE ), HR-deficient (Trp53-/-;Brca1-/-;MycOE ), and unclassified (Trp53-/-;Pten-/-;Nf1-/- ) organoids revealed differences in in vitro properties (proliferation, differentiation, and "secretome"), copy-number aberrations, and tumorigenicity. Tumorigenic organoids had variable sensitivity to HGSC chemotherapeutics, and evoked distinct immune microenvironments that could be modulated by neutralizing organoid-produced chemokines/cytokines. These findings enabled development of a chemotherapy/immunotherapy regimen that yielded durable, T cell-dependent responses in Trp53-/-;Ccne1OE;Akt2OE;Kras HGSC; in contrast, Trp53-/-;Pten-/-;Nf1-/- tumors failed to respond. Mouse and human HGSC models showed genotype-dependent similarities in chemosensitivity, secretome, and immune microenvironment. Genotype-informed, syngeneic organoid models could provide a platform for the rapid evaluation of tumor biology and therapeutics. SIGNIFICANCE: The lack of genetically informed, diverse, immunocompetent models poses a major barrier to therapeutic development for many malignancies. Using engineered fallopian tube organoids to study the cell-autonomous and cell-nonautonomous effects of specific combinations of mutations found in HGSC, we suggest an effective combination treatment for the currently intractable CCNE1-amplified subgroup.This article is highlighted in the In This Issue feature, p. 211.

Pathologic analysis of ex vivo plasma energy tumor destruction in patients with ovarian or peritoneal cancer.

INTRODUCTION: Cytoreduction of all visible disease has been associated with improved survival in patients with advanced-stage ovarian or peritoneal cancer. This is best achieved by minimizing injury to normal tissues. We report on the tumor destruction potential, in an ex vivo model, of a novel energy source that uses an electrically neutral beam of pure plasma to vaporize tissue. METHODS: Tumors were harvested from patients undergoing primary surgical cytoreduction for ovarian or peritoneal cancer. Specimens were divided into 1-cm sections and treated with pure plasma energy for 2 or 4 seconds using standardized power settings. Bright-field microscopy was used to measure the depth of tissue vaporization and lateral thermal damage (LTD). RESULTS: The mean (SD) tissue vaporization depth was 2.7 (1.3) mm (n = 96). Lateral thermal damage was minimal at all tissue interaction settings (0.13 [0.031] mm). Lateral thermal damage was approximately 5% of the depth of tissue vaporization. Tissue interaction time was a more powerful predictor of vaporization than power. When tissue interaction time increased from 2 to 4 seconds, depth of vaporization and LTD increased by 1.7 and 0.03 mm, respectively (P < 0.001 for both). When power was increased from low to high settings, depth of vaporization increased by 0.6 mm (P = 0.02), and LTD did not change. CONCLUSIONS: Plasma energy can effectively vaporize ovarian and peritoneal cancer cells. Greater power and tissue interaction time results in more tumor vaporization while maintaining minimal LTD. This is an attractive characteristic of plasma energy that may be useful for eradicating tumor from visceral surfaces.

Immune-Active Microenvironment in Small Cell Carcinoma of the Ovary, Hypercalcemic Type: Rationale for Immune Checkpoint Blockade.

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), is a highly aggressive monogenic cancer driven by SMARCA4 mutations. Here, we report responses to anti-PD1 immunotherapy in four patients and characterize the immune landscape of SCCOHT tumors using quantitative immunofluorescence and gene expression profiling. Unexpectedly for a low mutation burden cancer, the majority of the tumors (eight of 11 cases) demonstrated PD-L1 expression with strong associated T-cell infiltration (R2 = 0.60-0.95). PD-L1 expression was detected in both tumor and stromal cells, with macrophages being the most abundant PD-L1-positive cells in some tumors (three of 11 cases). Transcriptional profiling revealed increased expression of genes related to Th1 and cytotoxic cell function in PD-L1-high tumors, suggesting that PD-L1 acts as a pathway of adaptive immune resistance in SCCOHT. These findings suggest that although SCCOHT are low-mutational burden tumors, their immunogenic microenvironment resembles the landscape of tumors that respond well to treatment with PD-1/PD-L1 blockade.

A pair of datasets for microRNA expression profiling to examine the use of careful study design for assigning arrays to samples.

We set out to demonstrate the logistic feasibility of careful experimental design for microarray studies and its level of scientific benefits for improving the accuracy and reproducibility of data inference. Towards this end, we conducted a study of microRNA expression using endometrioid endometrial tumours (n=96) and serous ovarian tumours (n=96) that were primary, untreated, and collected from 2000 to 2012 at Memorial Sloan Kettering Cancer Center. The same set of tumour tissue samples were profiled twice using the Agilent microRNA microarrays: once under an ideal experimental condition with balanced array-to-sample allocation and uniform handling; a second time by mimicking typical practice, with arrays assigned in the order of sample collection and processed by two technicians in multiple batches. This paper provides a detailed description of the generation and validation of this unique dataset pair so that the research community can re-use it to investigate other statistical questions regarding microarray study design and data analysis, and to address biological questions on the relevance of microRNA expression in gynaecologic cancer.

Noninvasive ovarian cancer biomarker detection via an optical nanosensor implant.

Patients with high-grade serous ovarian carcinoma (HGSC) exhibit poor 5-year survival rates, which may be significantly improved by early-stage detection. The U.S. Food and Drug Administration-approved biomarkers for HGSC-CA-125 (cancer antigen 125) and HE4 (human epididymis protein 4)-do not generally appear at detectable levels in the serum until advanced stages of the disease. An implantable device placed proximal to disease sites, such as in or near the fallopian tube, ovary, uterine cavity, or peritoneal cavity, may constitute a feasible strategy to improve detection of HGSC. We engineered a prototype optical sensor composed of an antibody-functionalized carbon nanotube complex, which responds quantitatively to HE4 via modulation of the nanotube optical bandgap. The complexes measured HE4 with nanomolar sensitivity to differentiate disease from benign patient biofluids. The sensors were implanted into four models of ovarian cancer, within a semipermeable membrane, enabling the optical detection of HE4 within the live animals. We present the first in vivo optical nanosensor capable of noninvasive cancer biomarker detection in orthotopic models of disease.

Molecular analysis of high-grade serous ovarian carcinoma with and without associated serous tubal intra-epithelial carcinoma.

Many high-grade serous carcinomas (HGSCs) of the pelvis are thought to originate in the distal portion of the fallopian tube. Serous tubal intra-epithelial carcinoma (STIC) lesions are the putative precursor to HGSC and identifiable in ~ 50% of advanced stage cases. To better understand the molecular etiology of HGSCs, we report a multi-center integrated genomic analysis of advanced stage tumors with and without STIC lesions and normal tissues. The most significant focal DNA SCNAs were shared between cases with and without STIC lesions. The RNA sequence and the miRNA data did not identify any clear separation between cases with and without STIC lesions. HGSCs had molecular profiles more similar to normal fallopian tube epithelium than ovarian surface epithelium or peritoneum. The data suggest that the molecular features of HGSCs with and without associated STIC lesions are mostly shared, indicating a common biologic origin, likely to be the distal fallopian tube among all cases.High-grade serous carcinomas (HGSCs) are associated with precursor lesions (STICs) in the fallopian epithelium in only half of the cases. Here the authors report the molecular analysis of HGSCs with and without associated STICs and show similar profiles supporting a common origin for all HGSCs.

miR-200c-driven Mesenchymal-To-Epithelial Transition is a Therapeutic Target in Uterine Carcinosarcomas.

Uterine carcinosarcomas (UCSs) are highly aggressive malignancies associated with poor prognoses and limited treatment options. These tumors are hypothesized to develop from the endometrial adenocarcinoma (EAC) through epithelial-mesenchymal transition (EMT). We test this long-standing hypothesis by depleting miR-200, a family of microRNAs critical for EMT, in EAC cell lines. Our data suggest that UCSs do not develop from EACs via EMT. Clinically more relevant, we show that miR-200 expression in UCS cells induces a robust mesenchymal-epithelial transition (MET). Using in vitro and murine xenograft models, we demonstrate decreased growth and aggressiveness of miR-200-overexpressing UCS cell lines. Whole transcriptome analysis confirmed changes consistent with an MET and also revealed changes in angiogenic genes expression. Finally, by treatment of UCS-xenografted mice with miR-200c incorporated in DOPC nanoliposomes, we demonstrate anti-tumor activities. These findings suggest that ectopic miR-200 expression using advanced microRNA therapeutics may be a potential treatment approach for patients with UCS.

Antibodies Against Specific MUC16 Glycosylation Sites Inhibit Ovarian Cancer Growth.

Expression of the retained C-terminal extracellular portion of the ovarian cancer glycoprotein MUC16 induces transformation and tumor growth. However, the mechanisms of MUC16 oncogenesis related to glycosylation are not clearly defined. We establish that MUC16 oncogenic effects are mediated through MGAT5-dependent N-glycosylation of two specific asparagine sites within its 58 amino acid ectodomain. Oncogenic signaling from the C-terminal portion of MUC16 requires the presence of Galectin-3 and growth factor receptors colocalized on lipid rafts. These effects are blocked upon loss of either Galectin-3 expression or activity MGAT5. Using synthetic MUC16 glycopeptides, we developed novel N-glycosylation site directed monoclonal antibodies that block Galectin-3-mediated MUC16 interactions with cell surface signaling molecules. These antibodies inhibit invasion of ovarian cancer cells, directly blocking the in vivo growth of MUC16-bearing ovarian cancer xenografts, elucidating new therapeutic modalities.

Increased progesterone receptor expression in benign epithelium of BRCA1-related breast cancers.

The study of pathologically normal breast epithelium of BRCA mutation carriers may yield insights into the early natural history of breast tumorigenesis. Hormone receptor expression was assessed in 24 cases of invasive breast cancer associated with a mutation in BRCA1 (n = 15) or BRCA2 (n = 9) and in 39 sporadic cases matched for patient age and tumor hormone receptor status. Expression of progesterone receptor was significantly (P = 0.0003) more common in normal breast epithelium adjacent to invasive breast carcinoma in BRCA1-linked cases compared with sporadic cases. The wild-type BRCA allele was retained in normal epithelium of all cases tested. We conclude that deregulation of progesterone receptor expression, as a result of BRCA1 haploinsufficiency, may represent an early event in BRCA1-linked breast tumorigenesis.

Loss of SMARCA4 Expression Is Both Sensitive and Specific for the Diagnosis of Small Cell Carcinoma of Ovary, Hypercalcemic Type.

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a rare ovarian neoplasm that occurs in young women and has a poor prognosis. The histologic diagnosis of SCCOHT can be challenging due to its rarity and relatively nonspecific histologic features, which range from the classic, first-described small cell morphology to a pattern in which there are large cells with abundant eosinophilic cytoplasm. Many entities can be in the differential diagnosis and to date, immunohistochemical stains have shown no distinctive profile and have been of limited aid. SMARCA4 (also known as BRG1) mutations have recently been reported at high frequency in these tumors. SMARCA4 is an important component of the SWI/SNF complex that regulates gene expression through alteration of nucleosome conformation. Studies to date have suggested that immunohistochemical loss of expression of SMARCA4 is associated with the presence of a SMARCA4 mutation in most cases. In this study, the sensitivity and specificity of the immunohistochemical loss of SMARCA4 expression for the diagnosis of SCCOHT is examined in the context of the differential diagnosis with other primary or metastatic ovarian tumors. All but one of the SCCOHT showed loss of SMARCA4 expression (16/17; 94%), while of 279 other tumors tested, only two tumors (one clear cell carcinoma and one ovarian melanoma) showed loss of SMARCA4 expression. We conclude that SMARCA4 immunohistochemistry is highly sensitive and specific for a diagnosis of SCCOHT and is of clinical utility in the differential diagnosis of poorly differentiated ovarian tumors.