Splice-Variant Knock-Out of TGFβ Receptors Perturbates the Proteome of Ovarian Carcinoma Cells

The aim of this study was to analyze the biological role of different transforming growth factor-β (TGFβ) receptor splice variants in ovarian carcinoma (OC). Specific receptor variant knockouts (KO) were prepared using the CRISPR/Cas9 genome editing system in two OC cell lines, TβRI variant 1 (TβRIv1) KO in ES-2 cells and TβRII variant 1 (TβRIIv1) KO in OVCAR-8 cells. Control and KO cells were compared by proteomic analysis, functional tests, analysis of epithelial–mesenchymal transition (EMT) drivers, and Western blot of signaling proteins. Proteomic analysis revealed significant changes in protein pathways in the KO cells. TβRIv1 KO resulted in a significant reduction in both cellular motility and invasion, while TβRIIv1 KO significantly reduced cellular motility and increased Reactive Oxygen Species (ROS) production. Both receptor variant KOs reduced MET protein levels. Of the EMT drivers, a significant decrease in TWIST protein expression, and increase in SNAIL protein and MALAT1 mRNA levels were observed in the TβRIIv1 KO compared to control. A significant decrease in JNK1 and JNK2 activation was found in the TβRIv1 KO compared to control cells. These findings provide new insight regarding the biological role of the TGFβ receptor variants in the biology and potentially the progression of OC.

The Biological Role of the Long Non-coding RNA LINK-A in Ovarian Carcinoma

AIM

To analyze the biological role of the long non-coding RNA LINK-A.

MATERIALS AND METHODS

An 850-bp segment from the second exon of LINK-A was removed using the CRISPR/Cas9 system in OVCA433 ovarian serous carcinoma cells. Spheroid formation, migration, invasion, proliferation, matrix metalloproteinase (MMP) activity and expression of cell-signaling proteins were assessed in vitro.

RESULTS

OVCA433 cells with LINK-A deletion were more invasive (p=0.0008) but had reduced migration and MMP9 secretion compared to controls (p=0.003 and p=0.005, respectively). LINK-A deletion did not affect proliferation but induced phosphorylation of extracellular signal-regulated kinase (10-fold; p=0.005). LINK-A knock out additionally reduced spheroid formation.

CONCLUSION

Added to our previous data from analysis of clinical specimens, LINK-A is likely to be a tumor suppressor.

The Biological and Clinical Role of the Long Non-Coding RNA LOC642852 in Ovarian Carcinoma

The objective of the present study was to analyze the biological and clinical role of the long non-coding RNA LOC642852 in ovarian carcinoma (OC). LOC642852 expression was analyzed in seven OC cell lines (OVCAR-3, OVCAR-8, OVCA 433, OVCA 429, OC 238, DOV13, ES-2) and 139 high-grade serous carcinoma (HGSC) specimens (85 effusions, 54 surgical specimens). Following LOC642852 knockout (KO) using the CRISPR/Cas9 system, OVCAR-8 HGSC cells were analyzed for spheroid formation, migration, invasion, proliferation, matrix metalloproteinase (MMP) activity, and expression of cell signaling proteins. OVCAR-8 cells with LOC642852 KO were significantly less motile and less invasive compared to controls, with no differences in spheroid formation, proliferation, or matrix metalloproteinase (MMP) activity. Total Akt and Erk levels were comparable in controls and KO cells, but their phosphorylation was significantly increased in the latter. In clinical specimens, LOC642852 was overexpressed in ovarian tumors and omental/peritoneal metastases compared to effusion specimens (p = 0.013). A non-significant trend for shorter overall (p = 0.109) and progression-free (p = 0.056) survival was observed in patients with HGSC effusions with high LOC642852 levels. Bioinformatics analysis showed potential roles for LOC642852 as part of the TLE3/miR-221-3p ceRNA network and in relation to the FGFR3 protein. In conclusion, LOC642852 inactivation via CRISPR/Cas9 affects cell signaling, motility, and invasion in HGSC cells. LOC642852 is differentially expressed in HGSC cells at different anatomical sites. Its potential role in regulating the TLE3/miR-221-3p ceRNA network and FGFR3 merits further research.

Novel 3D embryo implantation model within macroporous alginate scaffolds

Background

Implantation failure remains an unsolved obstacle in reproductive medicine. Previous studies have indicated that estrogen responsiveness, specifically by estrogen receptor alpha (ERα), is crucial for proper implantation. There is an utmost need for a reliable in vitro model that mimics the events in the uterine wall during the implantation process for studying the regulatory mechanisms governing the process. The current two-dimensional and hydrogel-based in vitro models provide only short-term endometrial cell culture with partial functionality.

Results

Endometrial biopsies showed an increase in E-cadherin expression on the typical window of implantation of fertile women, compared to negligible expression in recurrent implantation failure (RIF) patients. These clinical results indicated E-cadherin as a marker for receptivity. Three-dimensional (3D) macroporous alginate scaffolds were the base for epithelial endometrial cell-seeding and long-term culture under hormone treatment that mimicked a typical menstrual cycle. The RL95–2 epithelial cell culture in macroporous scaffolds was viable for 3 weeks and showed increased E-cadherin levels in response to estrogen. Human choriocarcinoma (JAR) spheroids were used as embryo models, seeded onto cell constructs and successfully adhered to the RL95–2 cell culture. Moreover, a second model of HEC-1A with low ERα levels, showed lower E-cadherin expression and no JAR attachment. E-cadherin expression and JAR attachment were recovered in HEC-1A cells that were transfected with ERα plasmid.

Conclusions

We present a novel model that enables culturing endometrial cells on a 3D matrix for 3 weeks under hormonal treatment. It confirmed the importance of ERα function and E-cadherin for proper implantation. This platform may serve to elucidate the regulatory mechanisms controlling the implantation process, and for screening and evaluating potential novel therapeutic strategies for RIF.

Expression of Wnt pathway molecules is associated with disease outcome in metastatic high-grade serous carcinoma

The objective of this study was to analyze the expression and clinical role of Wnt pathway molecules in metastatic high-grade serous carcinoma (HGSC). mRNA expression by qPCR of 20 molecules related to Wnt signaling (WNT1, WNT2, WNT3, WNT4, WNT5A, WNT6, WNT7, WNT11, FZD1, FZD4, FZD5, FZD6, FZD7, FZD8, FZD10, LRP5, LRP6, DKK, CCND, RUNX2) was analyzed in 87 HGSC effusions. Thirty-nine surgical specimens (19 ovarian, 20 from other intra-abdominal sites) were analyzed for comparative purposes. Protein expression of YAP and LRP and their phosphorylated forms by western blotting were analyzed in 52 tumors. Significant differences in mRNA expression as a function of the anatomic site were observed for WNT3 (p = 0.005), WNT5A (p = 0.008), WNT7 (p < 0.001), FRZ5 (p = 0.04), and FRZ6 (p < 0.001). YAP and LRP and their phosphorylated forms were detected in HGSC specimens. FZD10 was overexpressed in effusions from patients who had complete response to chemotherapy compared with those with less favorable response (p = 0.037). WNT4 (p = 0.005), WNT7 (p = 0.047), RUNX2 (p = 0.038), LRP5 (p = 0.022), LRP6 (p = 0.011), FZD6 (p = 0.036), FZD7 (p = 0.004), and FZD10 (p = 0.015) levels were inversely related to primary chemoresistance. High FZD5 levels in pre-chemotherapy effusions tapped at diagnosis and high WNT2 levels in post-chemotherapy disease recurrence effusions were related to shorter overall survival (p = 0.018 and p = 0.011, respectively), whereas high RUNX2 (p = 0.031) and FZD1 (p = 0.029) in post-chemotherapy effusions were associated with longer overall survival. In multivariate analysis of post-chemotherapy cases, WNT2 (p = 0.002), RUNX2 (p = 0.017), FZD1 (p = 0.036), and FZD4 (p = 0.013) were independent prognosticators. In conclusion, expression of Wnt pathway molecules is anatomic site dependent. In HGSC effusions, it is informative of chemoresponse and survival.

SOX2 and SOX9 are markers of clinically aggressive disease in metastatic high-grade serous carcinoma

OBJECTIVE

The aim of this study was to analyze the expression, biological role and clinical relevance of cancer stem cell markers in high-grade serous carcinoma (HGSC).

METHODS

mRNA expression by qRT-PCR of NANOG, OCT4, SOX2, SOX4, SOX9, LIN28A and LIN28B was analyzed in 134 HGSC specimens (84 effusions, 50 surgical specimens). Nanog, OCT3/4, SOX2 and SOX9 protein expression by immunohistochemistry was analyzed in 52 HGSC effusions. Nanog protein expression in exosomes from 80 HGSC effusions was studied by Western Blotting. OVCAR3 cells underwent CRISPR/Cas9 Nanog knockout (KO), and the effect of Nanog KO on migration, invasion, proliferation and proteolytic activity was analyzed in OVCAR3 and OVCAR8 cells.

RESULTS

OCT4 mRNA was overexpressed in effusions compared to solid specimens (p = 0.046), whereas SOX9 was overexpressed in the ovarian tumors compared to effusions and solid metastases (p = 0.003). Higher SOX2 and SOX9 expression was associated with primary (intrinsic) chemoresistance (p = 0.009 and p = 0.02, respectively). Higher SOX9 levels were associated with shorter overall survival in univariate (p = 0.04) and multivariate (p = 0.049) analysis. OCT3/4, SOX2 and SOX9 proteins were found in HGSC cells, whereas Nanog was detected only in exosomes. Higher SOX2 protein expression was associated with shorter overall survival in univariate analysis (p = 0.049). OVCAR cells exposed to OVCAR3 NANOG KO exosomes had reduced migration, invasion and MMP9 activity.

CONCLUSIONS

SOX2 and SOX9 mRNA levels in HGSC effusions may be markers of clinically aggressive disease. Nanog is secreted in HGSC exosomes in effusions and modulates tumor-promoting cellular processes in vitro.

Abstract 5182: Activity and clinical relevance of autotaxin and lysophosphatidic acid pathways in high-grade serous carcinoma

Lysophosphatidic acid (LPA) is a bioactive phospholipid with mitogenic and growth factor-like activities affecting cell invasion, cancer progression and drug resistance. It is produced mainly by Autotaxin and acts on six G protein-coupled receptors, LPAR1-6. LPA has recently been implicated as a growth factor present in ascites of ovarian cancer patients. However, mitogenic pathways stimulated by LPA via its receptors are still far uncharacterized. Here we show that three LPA receptors are involved in the progression of the malignancy by the activation of both AKT and ERK pathways. We analyzed a set of 155 samples of high grade serous ovarian carcinoma (HGSC) from the three different anatomic sites of the disease. Results show that LPAR2 mRNA was overexpressed in HGSC cells in effusions compared to solid lesions, with opposite findings for LPAR3 and LPAR6 mRNA and ATX protein that was found mainly in exosomes. LPAR3 levels were significantly higher in pre-chemotherapy effusions compared to post-chemotherapy specimens (p=0.025). Higher expression of LPAR1 (p=0.037), LPAR2 (p=0.025) and LPAR5 (p=0.021) was significantly associated with shorter overall survival. Furthermore, we combined 3D (spheroids) and 2D cell culture models with gene editing using the CRISPR/Cas9 method for LPAR2, LPAR3 and LPAR6 and tested the effects of their silencing in vitro using OVCAR3 and ES2 cell lines. The p-ERK/ERK ratio was significantly elevated in LPAR3KO OVCAR3 cells cultured both in 2D and 3D form. Yet, LPAR2KO OVCAR3 cells expressed low levels of p-ERK/ERK in the 3D form, suggesting that LPAR3 inhibits p-ERK activity downstream, while LPAR2 activates it. ES2 LPAR2KO cells expressed elevated levels of p-AKT/AKT ratio in both the 2D and 3D forms. OVCAR3 LPAR6KO had low p-AKT/AKT ratio when cultured in 2D, but high ratio in the 3D form. LPAR KO further inhibited ovarian cancer invasion and motility.Our results demonstrate, for the first time, significant changes in LPARs' mRNA levels and Autotaxin protein levels with changes in anatomic sites of the disease that correlate to clinic-pathological parameters. Our study identifies a specific molecular machinery triggered by LPA and its' receptors that modulate tumor and can serve as therapeutic targets in this malignancy.

Citation Format: Hadil Onallah, Claes G Trope, Thea E. Hetland Falkenthal, Ben Davidson, Reuven Reich. Activity and clinical relevance of autotaxin and lysophosphatidic acid pathways in high-grade serous carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5182.

Expression and clinical role of long non-coding RNA in high-grade serous carcinoma

OBJECTIVE

To profile long non-coding RNA (lncRNA) expression at the various anatomic sites of high-grades serous carcinoma (HGSC) and in effusion-derived exosomes.

METHODS

LncRNA profiling was performed on 60 HGSC specimens, including 10 ovarian tumors, 10 solid metastases and 10 malignant effusions, as well as exosomes from 30 effusion supernatants. Anatomic site-related expression of ESRG, Link-A, GAS5, MEG3, GATS, PVT1 H19, Linc-RoR, HOTAIR and MALAT1 was validated by quantitative PCR and assessed for clinical relevance in a series of 77 HGSC effusions, 40 ovarian carcinomas, 21 solid metastases and 42 supernatant exosomes.

RESULTS

Significantly different (p<0.05) expression of 241, 406 and 3634 lncRNAs was found in comparative analysis of the ovarian tumors to solid metastases, effusions and exosomes, respectively. Cut-off at two-fold change in lncRNA expression identified 54 lncRNAs present at the 3 anatomic sites and in exosomes. Validation analysis showed significantly different expression of 5 of 10 lncRNAs in the 4 specimen groups (ESRG, Link-A, MEG3, GATS and PVT1, all p<0.001). Higher ESRG levels in HGSC effusions were associated with longer overall survival in the entire effusion cohort (p=0.023) and in patients with pre-chemotherapy effusions tapped at diagnosis (p=0.048). Higher Link-A levels were associated with better overall (p=0.015) and progression-free (p=0.023) survival for patients with post-chemotherapy effusions. Link-A was an independent prognostic marker in Cox multivariate analysis in the latter group (p=0.045).

CONCLUSIONS

We present the first evidence of differential LncRNA expression as function of anatomic site in HGSC. LncRNA levels in HGSC effusions are candidate prognostic markers.

TGFβ splicing and canonical pathway activation in high-grade serous carcinoma

The present study analyzed the expression and clinical role of the transforming growth factor-β (TGFβ) pathway in high-grade serous carcinoma (HGSC), with focus on malignant effusions. TGFβ1-3 and TGFβRI-III mRNA expression by qRT-PCR was analyzed in 70 HGSC effusions and 55 solid specimens (28 ovarian, 27 abdominal metastases). Protein expression of Smad2 and Smad3 and their phosphorylated forms by Western blotting was analyzed in 73 specimens (42 effusions, 13 ovarian carcinomas, 18 solid metastases). Expression was analyzed for association with anatomic site and clinical parameters, including survival. TGFβRI and TGFβRII mRNA was overexpressed in effusions and solid metastases, particularly the former, compared to that in the ovarian tumors (p < 0.001 to p = 0.05), with anatomic site-dependent expression of splice variants. Conversely, Smad2, p-Smad2, and p-Smad3 were overexpressed in solid specimens (ovarian and peritoneal) compared to those in effusions (p < 0.001 for all). In univariate survival analysis, higher TGFβRI variant 1 and TGFβRIII mRNA levels were associated with a trend for shorter overall survival in patients with post-chemotherapy effusions (p = 0.066 and p = 0.087, respectively), and the latter was an independent prognostic marker in Cox multivariate analysis (p = 0.041). Smad3 protein expression was associated with a trend for shorter overall survival in univariate survival analysis (p = 0.052). TGFβ receptor splice variant expression is anatomic site-dependent in HGSC. Elevated levels of TGFβ signaling pathway mRNAs are seen in metastatic HGSC, but are not accompanied by increased Smad expression and activation in HGSC effusions, evidence of failure to activate canonical TGFβ signaling. Assessment of the prognostic role of this pathway in HGSC effusions merits further research.

Uterine leiomyosarcoma and endometrial stromal sarcoma have unique miRNA signatures

OBJECTIVE

To compare the microRNA (miRNA) profiles of uterine endometrial stromal sarcoma (ESS) and leiomyosarcoma (LMS), and to compare the miRNA signatures of primary and metastatic uterine LMS.

METHODS

Eight primary LMS, 9 primary ESS and 8 metastatic LMS were analyzed for miRNA profiles using TaqMan Human miRNA Array Cards. Findings for 20 differentially expressed miRNAs were validated in a series of 44 uterine sarcomas (9 primary uterine ESS, 17 primary uterine LMS, 18 metastatic LMS) using qPCR. Frizzled-6 protein expression was analyzed in 30 LMS (15 primary, 15 metastases). Frizzled-6 was silenced in SK-LMS-1 uterine LMS cells using siRNA and the effect on invasion, wound healing and matrix metalloproteinase-2 (MMP2) activity was assessed.

RESULTS

Ninety-four miRNAs were significantly differentially expressed in ESS and LMS, of which 76 were overexpressed in ESS and 18 overexpressed in LMS. Forty-nine miRNAs were differentially expressed in primary and metastatic LMS, of which 45 were overexpressed in primary LMS and 4 in metastases. Differential expression was confirmed for 10/20 miRNA analyzed using qPCR. Frizzled-6 silencing in SK-LMS-1 cells significantly inhibited cellular invasion, wound healing and MMP-2 activity.

CONCLUSIONS

Differential miRNA signatures of ESS and LMS provide novel data regarding transcriptional regulation in these cancers, based on which new potential diagnostic markers, prognostic biomarkers and therapeutic targets may be explored. Differences in miRNA profiles of primary and metastatic LMS may improve our understanding of disease progression in this aggressive malignancy.

Abstract 5170: The autotaxin-lysophosphatidic acid signaling pathways in ovarian carcinoma

Ovarian carcinoma ranks as the fifth most common cancer among women. This is attributed to late presentation of the patients. The disease is characterized by widespread intraperitoneal metastases and accumulation of effusion fluids mainly in the peritoneal cavity

Lysophosphatidic acid (LPA) is a bioactive phospholipid with mitogenic and growth factor-like activities affecting cell invasion, cancer progression and resistance that act via specific cell-surface receptors present in many transformed cell types. LPA is produced by two main pathways, by PLA-2 and by Autotaxin (LysoPLD). Once its produced, it acts on six specific G protein coupled receptors, LPAR1-6. LPA has recently been implicated as a growth factor present in ascites of ovarian cancer patients. Previous studies have shown high levels of LPA in the effusions of ovarian carcinoma patients.

The aim of our study was to examine the role of ATX-LPA signaling in the progression of serous ovarian carcinoma. A total of 230 samples of serous ovarian carcinoma from the three different anatomic sites of the disease, were used .Effusion fluids were frozen and stored separately. All specimens were submitted for routine diagnostic purpose to the Division of Pathology at the Norwegian Radium Hospital during the period 1998-2008. mRNA levels of the six different LPA receptors were measured by RT-PCR, protein levels of Autotaxin were measured by Western blotting.

Results show that LPA2R is higher in effusion-derived tumor cells compared to solid lesions (p&lt;0.001), while the opposite was found for LPA3R (p&lt;0.001) and LPA6R (p&lt;0.001). Clinico-pathological analysis showed that LPA3R levels are significantly higher in pre-chemo patients (p = 0.038). LPA2R (p = 0.021) and LPA5R (p = 0.035) were found higher in cases with larger residual disease volume. LPA5R (p = 0.032) was higher in cases with primary chemo-resistance and LPA1R (p = 0.05) was marginally associated with better overall survival.

Autotaxin protein levels were lower in effusion-derived tumor cells compared to solid lesions (p&lt;0.001), yet higher levels of Autotaxin were found in peritoneal lesions compared to pleural ones (p = 0.033).

In this study we showed significant changes in mRNA LPAR levels and Autotaxin protein levels with the progression of the disease that correlates to clinic-pathological parameters.

To our best knowledge, this is the first description of the ATX-LPA signaling pathway in ovarian carcinoma with clinical relevance.

Citation Format: Hadil Onalla, Claes Tropé, Reuven Reich, Ben Davidson. The autotaxin-lysophosphatidic acid signaling pathways in ovarian 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 5170. doi:10.1158/1538-7445.AM2015-5170

Abstract 5166: THE WNT SIGNALING PATHWAY IN THE OVARIAN CARCINOMA

Ovarian carcinoma is the most lethal gynecological cancer and currently ranks as the fifth in causing cancer-related deaths among women. This is attributed to frequent presentation at late stage, when the tumor has metastasized, as well as to development of chemotherapy resistance along tumor progression. Patients with advanced-stage ovarian carcinoma have widespread intraperitoneal metastases, including the formation of malignant serous effusions within the peritoneal cavity. Unlike the majority of solid tumors, particularly at the primary site, cancer cells in effusions are not amenable to surgical removal, and failure in their eradication is one of the main causes of treatment failure.

Three WNT signaling pathways have been characterized: the canonical WNT pathway, the non-canonical planar cell polarity pathway, and the non-canonical WNT/calcium pathway. All three WNT signaling pathways are activated by the binding of a WNT-protein ligand to a Frizzled family receptor, which passes the biological signal inside the cell. Several lines of research indicate on the involvement of these pathways also in ovarian carcinomas. However, the specific pathway or their regulation in the process of tumor progression in this disease has not been elucidated, so far.

The aim of the current study is to identify the acting components of these pathways during tumor progression namely, which receptors and which ligands are activated at the different stages of ovarian carcinoma. We have analyzed the expression 7 frizzle genes (fzd1, 2, 4, 5, 6, 7, 8, 10), 4 WNT genes (wnt 2,3,4,5a,7) and 2 co-receptors LRP (5,6) on 222 samples (143 effusions, 44 primary, and 35 metastatic lesions) using real-time PCR. All the tested genes were found to be expressed at all sites. FRZ5 (p = 0.002), FRZ6 (p&lt;0.001), Wnt2 (p = 0.029), Wnt3 (p = 0.034) and Wnt6 (p = 0.022) were lower in effusion-derived cells compared to solids lesions. Further, Wnt2 expression was higher in pre-chemo (p = 0.037) samples compared to post-chemo ones. FRZ6 expression was higher in FIGO stage IV compared to stage III of the disease (p = 0.041), and FRZ4 expression was higher in cases with lower residual disease volume (p = 0.002). Wnt5a was higher in patients with better (complete) response (p = 0.019). FRZ6 expression was associated with poor overall survival (p = 0.045) and progression-free survival (p = 0.009). FRZ10 expression was associated with better overall survival (p = 0.005) and progression-free survival (p = 0.005).

Citation Format: michal chehover, Claes Tropé, Reuven Reich, Ben Davidson. THE WNT SIGNALING PATHWAY IN THE OVARIAN 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 5166. doi:10.1158/1538-7445.AM2015-5166

Abstract 3197: Exosome secretion in ovarian carcinoma

The purpose of this study is to elucidate the mechanism of exosome secretion in Ovarian Cancer (OC).

OC is the leading cause of death from gynecological cancers in western countries.

Exosomes, 30-100 nm vesicles, contain various lipids, proteins, and nucleic acids, exhibit paracrine bioactivities as well as distant transfer of regulatory messages to other cells. In our lab, the presence of OC derived exosomes accelerated cancerous pathologies in mice, thus determining OC derived exosomes as having a pro cancerous effect and therefore a worthy target for OC therapy.

The precise mechanism of the biogenesis and release of exosomes has yet to be elucidated; however, several studies have revealed the involvement of nSmase2, Tsap6 and Rab27a/b genes in these processes.

OC is characterized by primary solid tumors, solid metastases, and effusions to the peritoneal and pleural cavities as the tumor progresses. In order to develop a relevant model for solid tumors and effusions in vitro we utilized 3D Macro-porous alginate scaffolds and 3D OVCAR 8 cell line spheroids respectively.

In the present study, we examined the expression of the above mentioned genes at the mRNA and protein levels in human ovarian cancer samples derived from primary, metastatic lesions and from effusion derived OC cells and compared the expression profile to that of cell lines utilizing in our 3D in vitro model.

Our results show that in OC samples, nSMmase2, Tsap6 and Rab27a mRNA expression are significantly higher in effusions vs solid tumors (p&lt;0.026, p&lt;0.0001 and p&lt;0.02, respectively). Surprisingly, the protein content of these genes are significantly lower in effusions vs. the solid samples in these very same samples (p&lt;0.001-0.0001). This discrepancy is explained by the presence of nSMmase2, Tsap6 and Rab27a proteins in effusion fluid-derived exosomes.

Clinical analysis shows that elevated nSmase2 and Tsap6 mRNA expression correlates with poor survival (p&lt;0.036) and less favorable response to chemotherapy, respectively (p&lt;0.027). Furthermore, Rab27a protein is lower in pleural effusions compared to peritoneal effusions (p&lt;0.013).

In our in vitro model, mRNA analysis of OVCAR8 cells grown on alginate scaffold and spheroids show a higher expression of Tsap6 and Rab27a in spheroid cultures vs. scaffold cultures, corresponding with higher expression of these same genes in effusions vs. solid tumors in OC.

To the best of our knowledge, this is the first study to attempt to develop a 3D in vitro model for the various forms of OC that will enable research on the exosome secretion mechanism in this disease, hopefully leading to a fuller understanding of the exosomes secretion process and to the development novel therapies to address this disease.

Citation Format: Esther C. Broner, Tali Tavor Re'em, Claes Tropé, Ben Davidson, Reuven Reich. Exosome secretion in ovarian 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 3197. doi:10.1158/1538-7445.AM2015-3197

MicroRNAs in Ovarian Cancer

Ovarian cancer, consisting predominantly of ovarian carcinoma, is the eighth most common cancer in women and the most lethal gynecologic malignancy. Efforts focus on identifying biomarkers which may aid in early diagnosis and reduce mortality, as well as on characterizing therapeutic targets with the aim of circumventing chemoresistance and prolonging survival at advanced-stage disease. MicroRNAs (miRNAs) are small, non-coding RNAs that post-transcriptionally regulate gene expression, and have been found to play an important role in ovarian carcinoma. Recent research has identified multiple miRNAs involved in the biology and progression of the disease, and supports a role for miRNAs as potential biomarkers, predictive markers and prognostic factors. Many of the studies published to date nevertheless suffer from critical weaknesses which affect data quality and reproducibility, including the comparison of normal ovaries to tumor tissue without compensation for the highly discrepant target cell fraction in these two specimen types and the inclusion of carcinomas of different histotypes, non-epithelial tumors or tumors of non-specified histology. These shortcomings highlight the critical role of pathologists as part of the team in the setting of such research. This review summarizes current knowledge in this area and discusses the potential clinical relevance of miRNAs in ovarian carcinoma, with focus on studies of clinical specimens in which tissue selection has been deemed adequate.

Updated S2K AWMF guideline for the diagnosis and follow-up of obstructive sialadenitis--relevance for radiologic imaging

The interdisciplinarily developed German S2k AWMF guideline for the treatment of obstructive sialadenitis represents a new standard in the guideline program of the AWMF, the German Society for Consultants and the clinical disciplines working in the field of diseases of the head and neck region. In the last few years new diagnostic and therapeutic possibilities have been established in obstructive chronic Sialadenitis offering individually optimized therapeutic strategies. Only a few years ago extirpation of the whole affected gland was the only relevant therapy option. Nowadays therapeutic options such as interventional sialendoscopy and extracorporeal shock-wave lithotripsy (ESWL) are available in combination with marsupialization or incision of the duct. If possible the focus is on preserving the main glandular duct. In the following article the relevant aspects for the diagnostic radiologic procedures are presented.

Exosome-derived miRNAs and ovarian carcinoma progression

The objective of this study was to analyze the expression, biological role and clinical relevance of exosomal microRNAs (miRNAs) from ovarian carcinoma (OC) effusion supernatants. Exosomal miRNA expression profiling was performed using miRNA Taqman arrays. Selected miRNAs were validated using quantitative PCR in 86 OC effusion supernatants. The role of exosomal miRNA in this cancer was further studied using in vitro and in vivo models. miRNA profiling identified 99 miRNAs with high expression levels in exosomes from OC effusion supernatants. Quantitative PCR validation of 11 miRNAs showed significant associations with effusion site (peritoneum versus pleura) and International Federation of Gynecology and Obstetrics stage. In univariate survival analysis, high levels of miRNAs 21, 23b and 29a were associated with poor progression-free survival (P = 0.01, P = 0.015 and P = 0.009, respectively), whereas high expression of miRNA 21 correlated with poor overall survival (P = 0.017). The latter association was retained in Cox multivariate analysis (P = 0.001). Exposure of LP9 mesothelial cells and ES2 OC cells to OC effusion-derived exosomes inhibited tumor spheroid expansion and reduced mesothelial clearance area. Treatment of severe combined immunodeficiency mice with exosomes from OC effusions prior to injection of tumor cells was associated with larger tumor load, more infiltrative tumors and shorter survival. Patient-derived OC effusion exosomes contain multiple miRNAs, of which some may have clinical relevance. In experimental models, OC exosomes affect both tumor cells and cells in the tumor microenvironment and induce more aggressive disease. Collectively, these data demonstrate the central role of miRNAs and their content in the biology of this cancer.

Absorptionsänderungen von Chlorophyll-b im elektrischen Feld / Absorption Changes of Chlorophyll-b in the Electric Feld

In order to test recent interpretations of field indicating absorption changes in photosynthesis, the influence of the electric field on the absorption spectrum of chlorophyll-b is measured in vitro.

50 monomolecular layers of chlorophyll-b are built up on quartz slides by the technique of Blodgett and Langmuir. Absorption changes induced by an electric field linearly increasing from −1.8 · 106 V/cm to +1.8 · 106 V/cm are detected by a repetitive photometer. The absorption changes can be separated into one part, which is proportional to the electric field strength, and a second one, which is proportional to the square of it. The linear change of absorption in the region at ~650 nm may be interpreted as a shift of the absorption band of about .

The role of the tumor stroma in ovarian cancer

The tumor microenvironment, consisting of stromal myofibroblasts, endothelial cells, and leukocytes, is growingly perceived to be a major contributor to the pathogenesis and disease progression in practically all cancer types. Stromal myofibroblasts produce angiogenic factors, proteases, growth factors, immune response-modulating proteins, anti-apoptotic proteins, and signaling molecules, and express surface receptors and respond to stimuli initiated in the tumor cells to establish a bi-directional communication network in the microenvironment to promote tumor cell invasion and metastasis. Many of these molecules are candidates for targeted therapy and the cancer stroma has been recently regarded as target for biological intervention. This review provides an overview of the biology and clinical role of the stroma in ovarian cancer.

[The new S2k AWMF guideline for the treatment of obstructive sialadenitis in commented short form]

A new and interdisciplinary S2k AWMF guideline for the treatment of obstructive sialadenitis has been published. There have been several technical achievements, for instance in the field of ultrasonography, via sialendoscopy, or by MR-sialography, that have increased the possibilities for diagnosis and treatment of patients with obstructive sialadenitis. In the past, the treatment of choice in case of unsuccessful medical treatment was a complete extirpation of the affected salivary gland. Nowadays, using a variety of modern treatment options (like sialendoscopy, or extracorporeal shock-waves lithotripsy sometimes combined with salivary duct incision), it is possible in most patients, especially in cases of sialolithiasis, to preserve the affected gland. A functional recovery after gland-sparing surgery is described but more data is needed to finally evaluate the long-time results. The new guideline describes all relevant steps to diagnose an obstructive sialadenitis and values all diagnostic tools critically. Finally, all recommendable therapy options are described and valued, too.

Abstract 3052: Ovarian carcinoma derived exosomes: miRNA signatures and role in cancer progression

Ovarian cancer (OC) is the leading cause of death from gynecological cancer in Western countries. The disease is asymptomatic in the early stages, and is usually diagnosed at an advance stage, leading to an extremely poor prognosis. Primary solid tumor, solid metastases, and effusions to the peritoneal and pleural cavities characterize the tumor as it progresses.

MicroRNAs (miRNAs, miRs) are small, non-coding RNAs. They regulate gene expression by binding to the 3′UTR of a target mRNA, and decrease protein levels by inhibition of protein translation. In the recent years, miRNAs were found to play an important role in cancer, both as oncogenes and as tumor suppressor genes, depending on the target mRNA and the type of cancer.

In addition to cells, miRNAs are present in body fluids in exosomes, 30-90 nm vesicles secreted by cells. Exosomes contain proteins, mRNA and miRNA. Exosomal RNA content can be shuttled from one cell to another, affecting the recipient cell. It has been implicated that an "exosomal messenger system" exhibits paracrine bioactivities that facilitate tumor communication within the local tumor microenvironment.

We compared the expression of miRNAs present in effusion fluid-derived exosomes from 50 pre-chemo and 50 post-chemo patients of which 37 were chemo-resistant and 31chemo-sensitive, respectively. The patient cohort was in addition divided into 28 long and 72 short survivors, respectively. TaqMan miRNA arrays were used to identify miRNA profiles, and the qPCR miScript system for validation of the obtained results. Web-based algorithms were used for further bioinformatics analysis.

We identified differentially expressed miRNAs in OC effusion-derived exosomes compared to exosomal miRNAs from sera, malignant mesothelioma effusions and reactive effusions. Fifty-seven miRNAs were differentially expressed in specimens from patients with long vs. short survival and 62 differentially expressed miRNAs in specimens obtained before vs. after chemotherapy treatment.

We tested the effects of effusion derived exosomes on cell behavior in-vitro and on tumor spread in-vivo. Our results show that exosomes affect the interaction between cancer cells and their microenvironment. Pre-injection of exosomes to female SCID mice, followed by injection of cancer cells, caused shorter life span and larger tumor burden, compared to mice not pre-treated with exosomes. OC effusion derived exosomes might have autocrine and/or paracrine effects on cells, thus enhancing the oncogenic potential of cancer cells, or sensitizing the body to malignant dissemination.

This is the first study to evaluate the differential expression of miRNAs in exosomes derived from OC ascites fluid. We believe that the differential expression and the distinct signatures of miRNAs possess diagnostic, prognostic and therapeutic potential.

Citation Format: Olga Vaksman (Goreshnik), Ben Davidson, Claes G. Trope’, Reuven Reich. Ovarian carcinoma derived exosomes: miRNA signatures and role in cancer progression . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3052. doi:10.1158/1538-7445.AM2013-3052

Vixapatin (VP12), a c-type lectin-protein from Vipera xantina palestinae venom: characterization as a novel anti-angiogenic compound

A C-type lectin-like protein (CTL), originally identified as VP12 and lately named Vixapatin, was isolated and characterized from Israeli viper Vipera xantina palestinae snake venom. This CTL was characterized as a selective α2β1 integrin inhibitor with anti-melanoma metastatic activity. The major aim of the present study was to prove the possibility that this protein is also a potent novel anti-angiogenic compound. Using an adhesion assay, we demonstrated that Vixapatin selectively and potently inhibited the α2 mediated adhesion of K562 over-expressing cells, with IC(50) of 3 nM. 3 nM Vixapatin blocked proliferation of human dermal microvascular endothelial cells (HDMEC); 25 nM inhibited collagen I induced migration of human fibrosarcoma HT-1080 cells; and 50 nM rat C6 glioma and human breast carcinoma MDA-MB-231 cells. 1 µM Vixapatin reduced HDMEC tube formation by 75% in a Matrigel assay. Furthermore, 1 µM Vixapatin decreased by 70% bFGF-induced physiological angiogenesis, and by 94% C6 glioma-induced pathological angiogenesis, in shell-less embryonic quail chorioallantoic membrane assay. Vixapatin's ability to inhibit all steps of the angiogenesis process suggest that it is a novel pharmacological tool for studying α2β1 integrin mediated angiogenesis and a lead compound for the development of a novel anti-angiogenic/angiostatic/anti-cancer drug.

Argonaute, Dicer, and Drosha are up-regulated along tumor progression in serous ovarian carcinoma

MicroRNAs are posttranscriptional regulators of messenger RNA synthesis that are intracellularly processed and transferred by the microRNA-regulating machinery consisting of Drosha, Dicer, and Argonaute. The present study analyzed the expression and clinical role of the microRNA-regulating machinery in advanced-stage ovarian carcinoma. Drosha, Dicer, Argonaute 1, and Argonaute 2 messenger RNA levels were analyzed in 144 specimens (82 effusions, 33 primary carcinomas, and 29 solid metastases) using quantitative polymerase chain reaction. Dicer, Argonaute 1, and Argonaute 2 protein levels were analyzed in 103 of the above specimens by Western blotting. Argonaute 1, Argonaute 2, and Drosha messenger RNAs were overexpressed in effusions compared with primary carcinomas and solid metastases (P<.001), whereas Argonaute 1 protein expression was highest in solid metastases (P=.004). Significantly higher expression of all 4 messenger RNAs was found in effusions compared with primary carcinomas (P<.001 to P=.006), whereas Argonaute 2 messenger RNA (P=.002), Drosha messenger RNA (P=.009), and Dicer protein (P=.006) were overexpressed in solid metastases compared with primary carcinomas. Drosha, Dicer, Argonaute 1, and Argonaute 2 messenger RNAs and protein levels in effusions were unrelated to clinicopathologic parameters. In primary carcinomas, higher levels of 3 messenger RNAs were significantly associated with high-grade histology (P=.003 for Dicer and P=.01 for Drosha and Argonaute 1). Higher Argonaute 2 messenger RNA levels in prechemotherapy effusions were related to shorter progression-free survival (P=.049), a finding that retained its significance in multivariate Cox analysis (P=.046). In conclusion, Drosha, Dicer, Argonaute 1, and Argonaute 2 are differentially expressed at different metastatic sites in ovarian carcinoma compared with primary carcinomas, suggesting a role for these molecules in tumor progression. Their clinical role in metastatic ovarian carcinoma merits further research.

IGF-1 deficiency in combination with a low basic hBD-2 and hBD-3 gene expression might counteract malignant transformation in pleomorphic adenomas in vitro

This study investigated the IGF-1-influence on oncological relevant genes in pleomorphic adenomas. Therefore A64-tumor cells were stimulated by recombinant IGF-1. After RNA-extraction, transcript levels of hBD-1, hBD-2, hBD-3, DEFA1/3, DEFA4, S100A4, Psoriasin, DOC-1, EGF, EGFR, and IGFR were analyzed by qRT-PCR at t = 0, 4, 8, 24, 48, and 72 hr. The gene-products were visualized by immunostaining. A64-tumor-cells were deficient for hBD-1 and IGF-1. IGF-1 downregulates hBD-2 and hBD-3 without influencing hBD-1-expression. IGF-1 only slightly affects DEFA1/3-, DEFA4-, S100A4-, Psoriasin-, DOC-1-, EGF-, EGFR-, and IGFR-gene-expression. IGF-1-deficiency combined with low basic hBD-2-gene-expression and hBD-3-gene-expression might counteract, whereas hBD-1-deficiency promotes malignant transformation in pleomorphic adenomas.

Epithelial-mesenchymal transition in ovarian carcinoma

Ovarian cancer is the most lethal gynecologic malignancy, with the majority of patients dying within 5 years of diagnosis. This poor survival of patients diagnosed with this malignancy is attributed to diagnosis at advanced stage, when the tumor has metastasized, and to chemotherapy resistance, either primary or developing along tumor progression. However, ovarian carcinomas, constituting the vast majority of ovarian cancers, additionally have unique biology, one aspect of which is the ability to co-express epithelial and mesenchymal determinants. epithelial–mesenchymal transition (EMT), a physiological process by which mesenchymal cells are formed and migrate to target organs during embryogenesis, is involved in cancer cell invasion and metastasis. However, these changes do not fully occur in ovarian carcinoma, and are even reversed in tumor cells present in malignant peritoneal and pleural effusions. This review summarizes current knowledge in this area, including the characteristics of EMT related to adhesion, transcriptional regulation and chemoresistance, and their clinical relevance, as well as the recently observed regulation of EMT by microRNA.

PRAME (preferentially expressed antigen of melanoma) is a novel marker for differentiating serous carcinoma from malignant mesothelioma

The PRAME (preferentially expressed antigen of melanoma) gene was previously shown to be overexpressed in ovarian/primary peritoneal serous carcinoma compared with malignant mesothelioma using gene expression arrays. The objective of this study was to validate this finding at the messenger RNA (mRNA) and protein levels. Quantitative real-time polymerase chain reaction analysis of 126 müllerian carcinomas and 23 malignant mesotheliomas showed significantly higher PRAME mRNA expression in the former tumor (P < .001; test sensitivity and specificity, 89% and 91%, respectively). PRAME protein was expressed in 41 of 50 müllerian carcinomas and 0 of 30 mesotheliomas using Western blotting (P < .001; test sensitivity and specificity, 82% and 100%, respectively). PRAME levels in müllerian carcinoma were unrelated to survival; however, PRAME protein expression was up-regulated in solid metastases compared with primary carcinoma and effusions (P < .001). Our data confirm that PRAME effectively differentiates müllerian carcinoma from malignant mesothelioma at the mRNA and protein levels, suggesting a role in the diagnostic workup of serosal cancers.

miRNA profiling along tumour progression in ovarian carcinoma

MicroRNAs (miRNAs) are small non-coding RNAs that exert a regulatory effect post-transcriptionally by binding target mRNAs and inhibiting gene translation. miRNA expression is deregulated in cancer. The aim of this study was to characterize the differences in miRNA expression pattern and the miRNA-regulating machinery between ovarian carcinoma (OC) cells in primary tumours versus effusions. Using miRNA array platforms, we analysed a set of 21 tumours (13 effusions, 8 primary carcinomas) and identified three sets of miRNAs, one that is highly expressed in both primary carcinomas and effusions, one overexpressed in primary carcinomas and one overexpressed in effusions. Levels of selected miRNAs were analysed using quantitative PCR in an independent set of 45 additional tumours (30 effusions, 15 primary carcinomas). Reduced miR-145 and miR-214 and elevated let-7f, miR-182, miR-210, miR-200c, miR-222 and miR-23a levels were found in effusions in both sets. In silico target prediction programs identified potential target genes for some of the differentially expressed miRNAs. Expression of zinc finger E-box binding homeobox (ZEB)1 and c-Myc, targets of miR-200c, as well as of p21 protein (Cdc42/Rac)-activated kinase (PAK)1 and phosphatase and tensin homologue deleted on chromosome 10 (PTEN), predicted targets of miR-222, were analysed. Inverse correlations between expression levels of the indicated miRNAs and of the predicted target genes were found. In addition, higher expression of the miRNA-processing molecules Ago1, Ago2 and Dicer was observed in effusions compared to primary carcinomas. In conclusion, our data are the first to document different miRNA expression and regulation profiles in primary and metastatic OC, suggesting a role for these molecules in tumour progression.

MicroRNAs are associated with human embryo implantation defects

BACKGROUND

Repeated implantation failure (RIF) is a major problem encountered in IVF. We have previously reported that RIF-IVF patients have a different endometrial gene expression profile during the window of implantation. Considering microRNA (miRNA) function in post-transcriptional regulation of gene expression, the aim of the study was to evaluate the involvement of miRNA in defects of endometrial receptivity.

METHODS

We used TaqMan miRNA array cards to identify the miRNAs differentially expressed in the secretory endometrium of RIF-IVF patients when compared with fertile women, and bioinformatics tools to identify their predicted targets and the molecular networks they may affect.

RESULTS

Comparing miRNA expression profiles, we identified 13 miRNAs, differentially expressed in RIF endometrial samples, that putatively regulate the expression of 3800 genes. We found that 10 miRNAs were overexpressed (including miR 145, 23b and 99a) and 3 were underexpressed. Using our previous gene expression analysis, we paralleled miRNA-mRNA expression profiling. By this means, we identified novel and previously characterized miRNA-regulated molecular pathways such as adherens junctions, cell adhesion molecules, Wnt-signaling, p53 signaling and cell cycle pathways. Consistent with the miRNA-predicted targets, mRNA levels of N-cadherin, H2AFX, netrin-4 and secreted frizzled-related protein-4, belonging to the cell adhesion molecules, Wnt signaling and cell cycle pathways were lower in RIF-IVF patients.

CONCLUSIONS

To our knowledge, this is the first study to evaluate the differential expression of miRNAs in the secretory endometrium of RIF-IVF patients. We suggest that the RIF-associated miRNAs could be exploited as new candidates for diagnosis and treatment of embryo implantation failures.

Orally active, antimetastatic, nontoxic diphenyl ether-derived carbamoylphosphonate matrix metalloproteinase inhibitors

Seven 4-phenoxybenzenesulfonamidopolymethylene carbamoylphosphonates (CPOs) bearing two to eight methylene units in the polymethylene chain were synthesized and evaluated as matrix metalloproteinase (MMP) inhibitors. The five lowest homologues [(CH₂)₂-₆] are selective MMP-2 inhibitors, whereas the two with the longest linkers [(CH₂)₇,₈] lack inhibitory activity. The most potent homologues are those with (CH₂)₅,₆; these two were evaluated for antimetastatic activity in a murine melanoma model and showed good potency both by oral and intraperitoneal administration without any toxic--including musculoskeletal--side effects. In contrast to the previously reported cis-ACCP, which was shown to inhibit MMP-2 for ∼30 min, the new compounds inhibit MMP activity for the duration of measurement, lasting several hours. Pharmacokinetic evaluation revealed, on the one hand, low oral bioavailability; on the other hand, a relatively large calculated volume of distribution, consistent with the observed reversible absorption of CPO 5 to hydroxyapatite, as a model for bone.

New determinates of disease progression and outcome in metastatic ovarian carcinoma

Ovarian cancer is the most lethal gynecologic malignancy. This is attributed to frequent presentation at late stage, when the tumor has metastasized, as well as to development of chemotherapy resistance along tumor progression. Patients with advanced-stage ovarian carcinoma have widespread intraperitoneal metastases, including the formation of malignant serous effusions within the peritoneal cavity. Pleural effusions constitute the most frequent site of distant metastasis (FIGO stage IV disease). Unlike the majority of solid tumors, particularly at the primary site, cancer cells in effusions are not amenable to surgical removal, and failure in their eradication is one of the main causes of treatment failure. Our research in recent years has demonstrated that a large number of cancer-associated molecules are differentially expressed in effusions compared to primary carcinomas and solid metastases. We have additionally observed that expression of several of these molecules differs between primary diagnosis (pre-chemotherapy) and disease recurrence (post-chemotherapy) specimens, and that they are significantly associated with response to chemotherapy and patient survival. These observations are thought to be related to disease progression, as well as to the unique microenvironment of effusions, and may have impact on the selection of targeted therapy in this cancer. This review discusses our recent observations with respect to the biology of ovarian carcinoma cells in effusions, and focuses on the clinical role of tumor-associated molecules at this anatomic site.

Netrin-4 is upregulated in breast carcinoma effusions compared to corresponding solid tumors

We recently identified overexpression of the NTN4 gene in breast carcinoma effusions compared to primary carcinomas using gene-expression arrays. The objective of this study was to validate this finding at protein level and analyze the clinical role of Netrin-4 in breast carcinoma effusions. We additionally studied Netrin-4 expression and its clinical relevance in Müllerian (ovarian, peritoneal, and tubal) carcinoma effusions. Sections from 82 breast carcinomas (53 effusions and 29 solid tumors) and 57 Müllerian carcinoma effusions were stained for Netrin-4 using immunohistochemistry. Immunoreactivity was scored in carcinoma cells and analyzed for association with clinicopathologic parameters, including survival. In breast carcinoma, expression of Netrin-4 was detected in carcinoma cells in 30/53 (57%) effusions compared to 3/29 (10%) solid tumors (P < 0.001). Netrin-4 was further expressed in 31/57 (54%) Müllerian carcinoma effusions. No association was found between Netrin-4 expression in breast or Müllerian carcinoma effusions and clinicopathologic parameters, including survival. Our data provide validation on protein level of upregulated Netrin-4 expression in breast carcinoma effusions. The frequent expression of Netrin-4 in Müllerian carcinoma effusions suggests a biological role for this molecule in metastases from gynecological malignancies. Netrin-4 expression in effusions does not appear to be a predictor of disease outcome.