Even Birkeland

Lack of Estrogen Receptor-α Is Associated with Epithelial–Mesenchymal Transition and PI3K Alterations in Endometrial Carcinoma

Purpose: We hypothesized that estrogen receptor-α (ER-α) status in endometrial carcinomas, associated with poor prognosis, is reflected in transcriptional signatures suggesting targets for new therapy. Experimental Design: Endometrial carcinoma samples in a primary investigation cohort (n = 76) and three independent validation cohorts (n = 155/286/111) were analyzed through integrated molecular profiling. Biomarkers were assessed by immunohistochemistry (IHC), DNA oligonucleotide microarray, quantitative PCR (qPCR), single-nucleotide polymorphism (SNP) array, and Sanger sequencing in the cohorts, annotated for comprehensive histopathologic and clinical data, including follow-up. Results: ER-α immunohistochemical staining was strongly associated with mRNA expression of the receptor gene (ESR1) and patient survival (both P < 0.001). ER-α negativity associated with activation of genes involved in Wnt-, Sonic Hedgehog-, and TGF-β signaling in the investigation cohort, indicating epithelial–mesenchymal transition (EMT). The association between low ER-α and EMT was validated in three independent datasets. Furthermore, phosphoinositide 3-kinase (PI3K) and mTOR inhibitors were among the top-ranked drug signatures negatively correlated with the ER-α–negative tumors. Low ER-α was significantly associated with PIK3CA amplifications but not mutations. Also, low ER-α was correlated to high expression of Stathmin, a marker associated with PTEN loss, and a high PI3K activation signature. Conclusion: Lack of ER-α in endometrial cancer is associated with EMT and reduced survival. We present a rationale for investigating ER-αs potential to predict response to PI3K/mTOR inhibitors in clinical trials and also suggest EMT inhibitors to ER-α–negative endometrial carcinomas. Clin Cancer Res; 19(5); 1094–105. ©2012 AACR.

Integrated Genomic Analysis of the 8q24 Amplification in Endometrial Cancers Identifies ATAD2 as Essential to MYC-Dependent Cancers

Chromosome 8q24 is the most commonly amplified region across multiple cancer types, and the typical length of the amplification suggests that it may target additional genes to MYC. To explore the roles of the genes most frequently included in 8q24 amplifications, we analyzed the relation between copy number alterations and gene expression in three sets of endometrial cancers (N = 252); and in glioblastoma, ovarian, and breast cancers profiled by TCGA. Among the genes neighbouring MYC, expression of the bromodomain-containing gene ATAD2 was the most associated with amplification. Bromodomain-containing genes have been implicated as mediators of MYC transcriptional function, and indeed ATAD2 expression was more closely associated with expression of genes known to be upregulated by MYC than was MYC itself. Amplifications of 8q24, expression of genes downstream from MYC, and overexpression of ATAD2 predicted poor outcome and increased from primary to metastatic lesions. Knockdown of ATAD2 and MYC in seven endometrial and 21 breast cancer cell lines demonstrated that cell lines that were dependent on MYC also depended upon ATAD2. These same cell lines were also the most sensitive to the histone deacetylase (HDAC) inhibitor Trichostatin-A, consistent with prior studies identifying bromodomain-containing proteins as targets of inhibition by HDAC inhibitors. Our data indicate high ATAD2 expression is a marker of aggressive endometrial cancers, and suggest specific inhibitors of ATAD2 may have therapeutic utility in these and other MYC-dependent cancers.

KRAS gene amplification and overexpression but not mutation associates with aggressive and metastatic endometrial cancer

Background:Three quarter of endometrial carcinomas are treated at early stage. Still, 15 to 20% of these patients experience recurrence, with little effect from systemic therapies. Homo sapiens v-Ki-ras2 Kirsten rat sarcoma viral oncogenes homologue (KRAS) mutations have been reported to have an important role in tumorigenesis for human cancers, but there is limited knowledge regarding clinical relevance of KRAS status in endometrial carcinomas.Methods:We have performed a comprehensive and integrated characterisation of genome-wide expression related to KRAS mutations and copy-number alterations in primary- and metastatic endometrial carcinoma lesions in relation to clinical and histopathological data. A primary investigation set and clinical validation set was applied, consisting of 414 primary tumours and 61 metastatic lesions totally.Results:Amplification and gain of KRAS present in 3% of the primary lesions and 18% of metastatic lesions correlated significantly with poor outcome, high International Federation of Gynaecology and Obstetrics stage, non-endometrioid subtype, high grade, aneuploidy, receptor loss and high KRAS mRNA levels, also found to be associated with aggressive phenotype. In contrast, KRAS mutations were present in 14.7% of primary lesions with no increase in metastatic lesions, and did not influence outcome, but was significantly associated with endometrioid subtype, low grade and obesity.Conclusion:These results support that KRAS amplification and KRAS mRNA expression, both increasing from primary to metastatic lesions, are relevant for endometrial carcinoma disease progression.

ARID1A loss is prevalent in endometrial hyperplasia with atypia and low-grade endometrioid carcinomas

ARID1A (AT-rich interactive domain 1A) has recently been identified as a tumor suppressor gene in various, predominantly gynecological cancers. We wanted to investigate the distribution of ARID1A in endometrial hyperplasia, carcinomas and metastatic lesions to elucidate the timing of expression loss of its protein ARID1A in the course of endometrial cancer carcinogenesis. In addition, we wanted to assess the relationship between the loss of ARID1A and clinicopathological variables in endometrial cancer in general and the endometrioid subtype in particular. We analyzed a prospectively collected series of 535 primary endometrial cancers, 77 metastatic lesions, as well as 38 retrospectively collected endometrial hyperplasias with evaluable immunohistochemical staining for ARID1A. Fresh frozen tissue was available for mRNA microarray analysis in 122 primary tumors in parallel. Loss of ARID1A protein expression was noted in none of the hyperplasias without atypia, 16% of hyperplasias with atypia, 19% of primary endometrioid tumors and 28% of metastatic lesions. Loss of ARID1A in primary tumor was significantly associated with endometrioid grade 1 or 2 and clear-cell histology, diploid tumor cells, younger patient age and deeper myometrial infiltration, but not survival. ARID1A RNA expression was significantly correlated with ARID1A protein loss. Thus, loss of ARID1A appears to be an early event in the carcinogenesis of endometrioid uterine carcinomas and the association with deep myometrial infiltration may suggest an importance for invasiveness.

Loss of GPER identifies new targets for therapy among a subgroup of ERα-positive endometrial cancer patients with poor outcome

Background:The G protein-coupled oestrogen receptor, GPER, has been suggested as an alternative oestrogen receptor. Our purpose was to investigate the potential of GPER as a prognostic and predictive marker in endometrial carcinoma and to search for new drug candidates to improve treatment of aggressive disease.Materials and method:A total of 767 primary endometrial carcinomas derived from three patient series, including an external dataset, were studied for protein and mRNA expression levels to investigate and validate if GPER loss identifies poor prognosis and new targets for therapy in endometrial carcinoma. Gene expression levels, according to ERα/GPER status, were used to search the connectivity map database for small molecular inhibitors with potential for treatment of metastatic disease for receptor status subgroups.Results:Loss of GPER protein is significantly correlated with low GPER mRNA, high FIGO stage, non-endometrioid histology, high grade, aneuploidy and ERα loss (all P-values ⩽0.05). Loss of GPER among ERα-positive patients identifies a subgroup with poor prognosis that until now has been unrecognised, with reduced 5-year survival from 93% to 76% (P=0.003). Additional loss of GPER from primary to metastatic lesion counterparts further supports that loss of GPER is associated with disease progression.Conclusion:These results support that GPER status adds clinically relevant information to ERα status in endometrial carcinoma and suggest a potential for new inhibitors in the treatment of metastatic endometrial cancers with ERα expression and GPER loss.

High Phospho-Stathmin(Serine38) Expression Identifies Aggressive Endometrial Cancer and Suggests an Association with PI3K Inhibition

Purpose: High Stathmin expression has recently been associated with clinical progress in endometrial cancers. Stathmin protein activity is modulated by phosphorylation, and the Serine38 site is one of four Stathmin phospho-sites. The presence and significance of pStathmin(S38) is largely unknown in human cancers, and we here examined the associations between this marker and tumor cell proliferation, clinicopathologic phenotype, and survival impact in endometrial cancer. A relationship with possible treatment targets was explored by integrated analysis of transcriptional alterations. Experimental Design: Primary endometrial cancers from two independent patient series (n = 518/n = 286) were analyzed. Biomarkers were assessed by immunohistochemistry, FISH, flow cytometry, DNA oligonucleotide microarray, single-nucleotide polymorphism array, and Sanger sequencing, and related to clinicopathologic annotations and follow-up information. Results: High pStathmin(S38) level was associated with poor prognosis, independent of other features, and correlated to increased tumor cell proliferation as well as high Stathmin levels. On the basis of transcriptional differences between high/low pStathmin(S38) tumors, phosphoinositide 3-kinase (PI3K)/mTOR/HSP90 were suggested as possible targets in pStathmin(S38)-high cases. High pStathmin(S38) was associated with several PI3K pathway alterations: amplification of the 3q26 region, increased PIK3CA copy number (FISH) and a PI3K activation score (all P < 0.05). Conclusions: High pStathmin(S38) is a novel biomarker of increased tumor cell proliferation and impaired prognosis as reported here for independent cohorts of endometrial cancer and not previously shown in human cancer. Our data support a rationale for further studies exploring effects of drugs inhibiting the PI3K signaling pathway in pStathmin(S38)-high endometrial cancer, including a potential value of pStathmin(S38) in predicting response to PI3K/mTOR/HSP90 inhibitors. Clin Cancer Res; 19(9); 2331–41. ©2013 AACR.

High-Throughput Mutation Profiling of Primary and Metastatic Endometrial Cancers Identifies KRAS, FGFR2 and PIK3CA to Be Frequently Mutated

Background Despite being the most common pelvic gynecologic malignancy in industrialized countries, no targeted therapies are available for patients with metastatic endometrial carcinoma. In order to improve treatment, underlying molecular characteristics of primary and metastatic disease must be explored. Methodology/Principal Findings We utilized the mass spectrometric-based mutation detection technology OncoMap to define the types and frequency of point somatic mutations in endometrial cancer. 67 primary tumors, 15 metastases corresponding to 7 of the included primary tumors and 11 endometrial cancer cell lines were screened for point mutations in 28 known oncogenes. We found that 27 (40.3%) of 67 primary tumors harbored one or more mutations with no increase in metastatic lesions. FGFR2, KRAS and PIK3CA were consistently the most frequently mutated genes in primary tumors, metastatic lesions and cell lines. Conclusions/Significance Our results emphasize the potential for targeting FGFR2, KRAS and PIK3CA mutations in endometrial cancer for development of novel therapeutic strategies.

Stathmin protein level, a potential predictive marker for taxane treatment response in endometrial cancer.

Stathmin is a prognostic marker in many cancers, including endometrial cancer. Preclinical studies, predominantly in breast cancer, have suggested that stathmin may additionally be a predictive marker for response to paclitaxel. We first evaluated the response to paclitaxel in endometrial cancer cell lines before and after stathmin knock-down. Subsequently we investigated the clinical response to paclitaxel containing chemotherapy in metastatic endometrial cancer in relation to stathmin protein level in tumors. Stathmin level was also determined in metastatic lesions, analyzing changes in biomarker status on disease progression. Knock-down of stathmin improved sensitivity to paclitaxel in endometrial carcinoma cell lines with both naturally higher and lower sensitivity to paclitaxel. In clinical samples, high stathmin level was demonstrated to be associated with poor response to paclitaxel containing chemotherapy and to reduced disease specific survival only in patients treated with such combination. Stathmin level increased significantly from primary to metastatic lesions. This study suggests, supported by both preclinical and clinical data, that stathmin could be a predictive biomarker for response to paclitaxel treatment in endometrial cancer. Re-assessment of stathmin level in metastatic lesions prior to treatment start may be relevant. Also, validation in a randomized clinical trial will be important.

Tumor necrosis is an important hallmark of aggressive endometrial cancer and associates with hypoxia, angiogenesis and inflammation responses.

Aims Tumor necrosis is associated with aggressive features of endometrial cancer and poor prognosis. Here, we investigated gene expression patterns and potential treatment targets related to presence of tumor necrosis in primary endometrial cancer lesions. Methods and Results By DNA microarray analysis, expression of genes related to tumor necrosis reflected multiple tumor-microenvironment interactions like tissue hypoxia, angiogenesis and inflammation pathways. A tumor necrosis signature of 38 genes and a related patient cluster (Cluster I, 67% of the cases) were associated with features of aggressive tumors such as type II cancers, estrogen receptor negative tumors and vascular invasion. Further, the tumor necrosis signature was increased in tumor cells grown in hypoxic conditions in vitro. Multiple genes with increased expression are known to be activated by HIF1A and NF-kB. Conclusions Our findings indicate that the presence of tumor necrosis within primary tumors is associated with hypoxia, angiogenesis and inflammation responses. HIF1A, NF-kB and PI3K/mTOR might be potential treatment targets in aggressive endometrial cancers with presence of tumor necrosis.

Endometrial Carcinoma Recurrence Score (ECARS) validates to identify aggressive disease and associates with markers of epithelial–mesenchymal transition and PI3K alterations

PURPOSE Our previously reported 29-gene expression signature identified an aggressive subgroup of endometrial cancer patients with PI3K activation. We here wanted to validate these findings by independent patient series. PATIENTS AND METHODS The 29-gene expression signature was assessed in fresh frozen tumor tissue from 280 primary endometrial carcinomas (three independent cohorts), 19 metastatic lesions and in 333 primary endometrial carcinomas using TCGA data, and expression was related to clinico-pathologic features and survival. The 29-gene signature was assessed by real-time quantitative PCR, DNA oligonucleotide microarrays, or RNA sequencing. PI3K alterations were assessed by immunohistochemistry, DNA microarrays, DNA sequencing, SNP arrays or fluorescence in situ hybridization. A panel of markers of epithelial-mesenchymal transition (EMT) was also correlated to the 29-gene signature score. RESULTS High 29-gene Endometrial Carcinoma Recurrence Score (ECARS) values consistently validated to identify patients with aggressive clinico-pathologic phenotype and reduced survival. Within the presumed favorable subgroups of low grade, endometrioid tumors confined to the uterus, high ECARS still predicted a poor prognosis. The score was higher in metastatic compared to primary lesions (P<0.001) and was significantly associated with potential measures of PI3K activation, markers of EMT and vascular invasion as an indicator of metastatic spread (all P<0.001). CONCLUSIONS ECARS validates to identify aggressive endometrial carcinomas in multiple, independent patients cohorts. The higher signature score in metastatic compared to primary lesions, and the potential link to PI3K activation and EMT, support further studies of ECARS in relation to response to PI3K and EMT inhibitors in clinical trials of metastatic endometrial carcinoma.