Helene Tuft Stavnes

Nuclear factor κB transcription factors are coexpressed and convey a poor outcome in ovarian cancer

Recent work has suggested a role for nuclear factor κB (NF‐κB) in the propagation of ovarian cancer cell lines, but the significance and mechanism of NF‐κB in ovarian cancer is unknown. The authors hypothesized that the NF‐κB pathway is over activated in aggressive ovarian 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.

Mesenchymal-to-epithelial transition determinants as characteristics of ovarian carcinoma effusions

The present study investigated the intracellular regulation of E-cadherin in ovarian carcinoma. E-cadherin expression and regulation by Snail and Pak1 were studied in ES-2 and OVCAR-3 ovarian cancer cells in vitro. Twist1, Zeb1 and Vimentin mRNA expression and HIF-1α protein expression were analyzed in 80 and 189 clinical specimens, respectively. OVCAR-3 cells incubated with an anti-E-cadherin antibody formed smaller and looser spheroids compared to controls. Snail silencing using Small Hairpin RNA in ES-2 cells reduced invasion and MMP-2 activity, with unaltered cellular morphology. Using dominant negative (DN) and constitutively active (CA) Pak1 constructs, we found that DN Pak1 ES-2 and OVCAR-3 clones had reduced attachment to matrix proteins, invasion and MMP-2 activity compared to CA and wild-type cells. DN Pak1 ES-2 cells also bound less to LP9 mesothelial cells. DN Pak1 OVCAR-3 cells had lower Vimentin levels. Snail expression was lower in cultured effusions compared to primary carcinomas, and was cytoplasmic rather than nuclear. Twist1 (Pxa0<xa00.001), Zeb1 (Pxa0=xa00.003) and Vimentin (Pxa0=xa00.03) mRNA expression was significantly higher in solid metastases compared to primary carcinomas and effusions. HIF-1α protein expression was lower in effusions compared to primary carcinomas and solid metastases (Pxa0=xa00.033). Our data suggest that the previously reported E-cadherin re-expression in ovarian carcinoma effusions is regulated by Pak1. The transient nature of E-cadherin expression during ovarian carcinoma progression is probably the result of partial epithelial-to-mesenchymal transition (EMT) and the reverse process of mesenchymal-to-epithelial-like transition (MET). Expression of the EMT-related molecules Twist, Zeb1, Vimentin and HIF-1α is anatomic site-dependent in ovarian carcinoma.

Tenascin-X is a novel diagnostic marker of malignant mesothelioma

Tenascin XB (TNXB) was previously identified as a gene that is more highly expressed in malignant mesothelioma compared with ovarian/peritoneal serous carcinoma based on gene expression array analysis. The objective of this study was to validate this finding at the mRNA and protein levels. Effusions (n=91; 71 ovarian carcinomas, 10 breast carcinomas, and 10 malignant mesotheliomas) were assayed for TNXB mRNA expression using quantitative polymerase chain reaction. Tenascin-X protein expression was studied in 183 effusions (137 carcinomas of different origin, 37 mesotheliomas, and 9 reactive effusions) and 178 solid lesions (122 ovarian/peritoneal carcinomas and 56 mesotheliomas) using immunohistochemistry. Quantitative polymerase chain reaction analysis showed significantly higher TNXB mRNA level in mesotheliomas compared with ovarian and breast carcinomas (P<0.001). By immunohistochemistry, tenascin-X protein expression was significantly higher in malignant mesothelioma compared with metastatic carcinoma in effusions (34 of 37 vs. 31 of 137 positive cases; sensitivity=92% and specificity=77%; P<0.001). Reactive mesothelial cells had focal or no tenascin-X expression. Tenascin-X protein was detected in 41 of 56 mesothelioma biopsy specimens and was uniformly absent from all 122 ovarian carcinomas (sensitivity=73% and specificity=100%; P<0.001). Our data suggest that tenascin-X may be a new diagnostic marker of malignant mesothelioma in the differential diagnosis of cancers involving the serosal cavities, particularly in the differential diagnosis between this tumor and ovarian/peritoneal serous carcinoma.

Gene expression signatures differentiate ovarian/peritoneal serous carcinoma from breast carcinoma in effusions

Ovarian/primary peritoneal carcinoma and breast carcinoma are the gynaecological cancers that most frequently involve the serosal cavities. With the objective of improving on the limited diagnostic panel currently available for the differential diagnosis of these two malignancies, as well as to define tumour‐specific biological targets, we compared their global gene expression patterns. Gene expression profiles of 10 serous ovarian/peritoneal and eight ductal breast carcinoma effusions were analysed using the HumanRef‐8 BeadChip from Illumina. Differentially expressed candidate genes were validated using quantitative real‐time PCR and immunohistochemistry. Unsupervised hierarchical clustering using all 54,675 genes in the array separated ovarian from breast carcinoma samples. We identified 288 unique probes that were significantly differentially expressed in the two cancers by greater than 3.5‐fold, of which 81 and 207 were overexpressed in breast and ovarian/peritoneal carcinoma, respectively. SAM analysis identified 1078 differentially expressed probes with false discovery rate less than 0.05. Genes overexpressed in breast carcinoma included TFF1, TFF3, FOXA1, CA12, GATA3, SDC1, PITX1, TH, EHFD1, EFEMP1, TOB1 and KLF2. Genes overexpressed in ovarian/peritoneal carcinoma included SPON1, RBP1, MFGE8, TM4SF12, MMP7, KLK5/6/7, FOLR1/3, PAX8, APOL2 and NRCAM. The differential expression of 14 genes was validated by quantitative real‐time PCR, and differences in 5 gene products were confirmed by immunohistochemistry. Expression profiling distinguishes ovarian/peritoneal carcinoma from breast carcinoma and identifies genes that are differentially expressed in these two tumour types. The molecular signatures unique to these cancers may facilitate their differential diagnosis and may provide a molecular basis for therapeutic target discovery.

Expression and clinical role of growth differentiation factor-15 in ovarian carcinoma effusions.

Introduction: Growth differentiation factor-15 (GDF-15) is a member of the transforming growth factor-β family. We analyzed the expression and clinical role of GDF-15 in ovarian carcinoma effusions. Methods: The concentration of soluble GDF-15 was measured in 195 effusion supernatants from 162 patients with ovarian carcinoma by an immunoradiometric assay. Tumor cell GDF-15 expression was investigated in 114 effusions from the same patients using immunohistochemistry. Results: Growth differentiation factor-15 was detected in all effusion supernatants by immunoradiometric assay. Growth differentiation factor-15 cytoplasmic expression in carcinoma cells was seen in 111 (97%) of 114 specimens. Effusion GDF-15 concentration correlated positively with GDF-15 tumor cell expression (P < 0.001). Growth differentiation factor-15 concentration was higher in effusions from patients who previously received chemotherapy compared with specimens from patients not treated with chemotherapy (P = 0.028). High GDF-15 effusion concentration was associated with poor response to chemotherapy at first disease recurrence (P = 0.001). In univariate survival analysis, high concentration of GDF-15 in effusions was associated with poor overall survival (P = 0.016), and this finding retained its prognostic value in Cox multivariate analysis (P = 0.01). Tumor cell expression of GDF-15 did not correlate with survival in analysis of the entire cohort. However, high tumor cell GDF-15 expression in prechemotherapy specimens was associated with poor progression-free survival (P = 0.046). Conclusions: Soluble GDF-15 is universally present in effusions from patients with ovarian carcinoma, and tumor cells represent a likely source for soluble GDF-15 in effusions. Growth differentiation factor-15 emerges as a potential prognostic biomarker in ovarian carcinoma.

Gene expression signatures differentiate adenocarcinoma of lung and breast origin in effusions.

Lung and breast adenocarcinoma at advanced stages commonly involve the serosal cavities, giving rise to malignant effusions. The aim of the present study was to compare the global gene expression patterns of metastases from these 2 malignancies, to expand and improve the diagnostic panel of biomarkers currently available for their differential diagnosis, as well as to define type-specific biological targets. Gene expression profiles of 7 breast and 4 lung adenocarcinoma effusions were analyzed using the HumanRef-8 BeadChip from Illumina. Differentially expressed candidate genes were validated using quantitative real-time polymerase chain reaction and immunohistochemistry. Unsupervised hierarchical clustering using all 54,675 genes in the array separated lung from breast adenocarcinoma samples. We identified 289 unique probes that were significantly differentially expressed in the 2 cancers by greater than 2-fold using moderated t statistics, of which 65 and 224 were overexpressed in breast and lung adenocarcinoma, respectively. Genes overexpressed in breast adenocarcinoma included TFF1, TFF3, FOXA1, CA12, PITX1, RARRES1, CITED4, MYC, TFAP2A, EFHD1, TOB1, SPDEF, FASN, and TH. Genes overexpressed in lung adenocarcinoma included TITF1, SFTPG, MMP7, EVA1, GPR116, HOP, SCGB3A2, and MET. The differential expression of 15 genes was validated by quantitative real-time PCR, and differences in 8 gene products were confirmed by immunohistochemistry. Expression profiling distinguishes breast adenocarcinoma from lung adenocarcinoma and identifies genes that are differentially expressed in these 2 tumor types. The molecular signatures unique to these cancers may facilitate their differential diagnosis and may provide a molecular basis for therapeutic target discovery.

Heat shock protein 90 is a putative therapeutic target in patients with recurrent advanced-stage ovarian carcinoma with serous effusions.

Heat shock protein 90 (HSP90) has anti-apoptotic properties exerted through its cytoprotective function of chaperone activity and increased expression in response to stress. The present study analyzed the clinical role of HSP90 in effusions from patients with advanced-stage ovarian carcinoma. HSP90 protein expression was investigated in 265 effusions using immunohistochemistry. Results were analyzed for association with clinicopathologic parameters, including chemotherapy response and survival. The correlation between HSP90 and a panel of previously-studied antiapoptotic proteins was additionally investigated. HSP90 was expressed in the cytoplasm and nucleus of tumor cells in 97% and 18% of specimens, respectively. Nuclear HSP90 expression was significantly higher in post-chemotherapy compared to pre-chemotherapy effusions (P = .005), significantly related to previous treatment with both platinol (P = .024) and paclitaxel (P = .007). Cytoplasmic HSP90 expression was significantly higher in effusions from patients with complete compared to incomplete/no response after second-line chemotherapy (P = .016). No association was found between HSP90 expression and other clinicopathologic parameters or survival. Cytoplasmic HSP90 expression was significantly associated with that of Bcl-2 in pre-chemotherapy effusions (P = .04), and marginally associated with cytoplasmic Survivin expression in post-chemotherapy effusions (P = .05). HSP90 is upregulated along tumor progression from primary diagnosis to recurrent effusion. HSP90 does not provide prognostic data in patients with advanced ovarian carcinoma effusions. However, HSP90 may be of predictive value as to who will benefit from treatment with HSP90 inhibitors to potentiate the effectiveness of platinol and paclitaxel in patients with recurrent advanced ovarian carcinoma effusions. We propose HSP90 as a potential therapeutic target in this patient group.

Expression of the peroxisome proliferator–activated receptors–α, –β, and –γ in ovarian carcinoma effusions is associated with poor chemoresponse and shorter survival

Peroxisome proliferator-activated receptors regulate lipid metabolism, affecting inflammation and cancer. The present study analyzed the anatomical site-related expression and prognostic role of peroxisome proliferator-activated receptors in ovarian carcinoma. Fresh-frozen effusions (n = 79), primary carcinomas (n = 44), and solid metastases (n = 16) were studied for peroxisome proliferator-activated receptor-alpha, -beta, and -gamma messenger RNA expression using reverse transcriptase polymerase chain reaction. Peroxisome proliferator-activated receptor-gamma messenger RNA expression was further assessed in 60 tumors (30 effusions, 20 primary carcinomas, 10 metastases) using in situ hybridization. Peroxisome proliferator-activated receptor-gamma protein expression was immunohistochemically analyzed in 160 effusions. All peroxisome proliferator-activated receptors were expressed in most tumors at all anatomical sites using reverse transcriptase polymerase chain reaction, but peroxisome proliferator-activated receptor-alpha (P = .004) and peroxisome proliferator-activated receptor-beta (P = .002) messenger RNA levels were higher in effusions compared with primary carcinomas and solid metastases. In situ hybridization localized peroxisome proliferator-activated receptor-gamma messenger RNA to carcinoma cells in both effusions and solid lesions. Peroxisome proliferator-activated receptor-gamma protein was detected in carcinoma cells in 102 of 160 (64%) effusions. Higher effusion messenger RNA levels of all peroxisome proliferator-activated receptors were associated with less favorable response to chemotherapy at diagnosis (P = .009). In univariate survival analysis, higher messenger RNA expression of all peroxisome proliferator-activated receptors was associated with poor progression-free (P = .045) and overall (P = .014) survival. Higher peroxisome proliferator-activated receptor-gamma protein expression was similarly associated with poor overall survival for the entire cohort (P = .046) and for patients with disease recurrence effusions (P = .009). Peroxisome proliferator-activated receptors were not independent predictors of survival in Cox multivariate analysis. Peroxisome proliferator-activated receptor members are frequently expressed in ovarian carcinoma, with upregulated expression in effusions. Peroxisome proliferator-activated receptor expression in effusions is associated with poor response to chemotherapy at disease recurrence and poor survival, suggesting a role in tumor biology at this unique microenvironment.

Endoglin (CD105) expression in ovarian serous carcinoma effusions is related to chemotherapy status

Endoglin (CD105), a cell surface co-receptor for transforming growth factor-β, is expressed in proliferating endothelial cells, as well as in cancer cells. We studied endoglin expression and its clinical relevance in effusions, primary tumors, and solid metastatic lesions from women with advanced-stage ovarian serous carcinoma. Endoglin expression was analyzed by immunohistochemistry in effusions (nu2009=u2009211; 174 peritoneal, 37 pleural). Cellular endoglin staining was analyzed for association with the concentration of soluble endoglin (previously determined by ELISA) in 95 corresponding effusions and analyzed for correlation with clinicopathologic parameters, including survival. Endoglin expression was additionally studied in 34 patient-matched primary tumors and solid metastases. Carcinoma and mesothelial cells expressed endoglin in 95/211 (45%) and 133/211 (63%) effusions, respectively. Carcinoma cell endoglin expression was more frequent in effusions from patients aged ≤60xa0years (pu2009=u20090.048) and in post- compared to prechemotherapy effusions (pu2009=u20090.014), whereas mesothelial cell endoglin expression was higher in prechemotherapy effusions (pu2009=u20090.021). No association was found between cellular endoglin expression and its soluble effusion concentration. Endoglin was expressed in 17/34 (50%) primary tumors and 19/34 (56%) metastases, with significantly higher percentage of immunostained cells in solid metastases compared to effusions (pu2009=u20090.036). Endoglin expression did not correlate with survival. Tumor cell endoglin expression is higher in post- vs. prechemotherapy effusions, whereas the opposite is seen in mesothelial cells. Together with its upregulation in solid metastases, this suggests that the expression and biological role of endoglin may differ between cell populations and change along tumor progression in ovarian carcinoma.