Elisabeth Wik

Landscape of genomic alterations in cervical carcinomas

Cervical cancer is responsible for 10–15% of cancer-related deaths in women worldwide. The aetiological role of infection with high-risk human papilloma viruses (HPVs) in cervical carcinomas is well established. Previous studies have also implicated somatic mutations in PIK3CA, PTEN, TP53, STK11 and KRAS as well as several copy-number alterations in the pathogenesis of cervical carcinomas. Here we report whole-exome sequencing analysis of 115 cervical carcinoma–normal paired samples, transcriptome sequencing of 79 cases and whole-genome sequencing of 14 tumour–normal pairs. Previously unknown somatic mutations in 79 primary squamous cell carcinomas include recurrent E322K substitutions in the MAPK1 gene (8%), inactivating mutations in the HLA-B gene (9%), and mutations in EP300 (16%), FBXW7 (15%), NFE2L2 (4%), TP53 (5%) and ERBB2 (6%). We also observe somatic ELF3 (13%) and CBFB (8%) mutations in 24 adenocarcinomas. Squamous cell carcinomas have higher frequencies of somatic nucleotide substitutions occurring at cytosines preceded by thymines (Tp*C sites) than adenocarcinomas. Gene expression levels at HPV integration sites were statistically significantly higher in tumours with HPV integration compared with expression of the same genes in tumours without viral integration at the same site. These data demonstrate several recurrent genomic alterations in cervical carcinomas that suggest new strategies to combat this disease.

Integrated genomic profiling of endometrial carcinoma associates aggressive tumors with indicators of PI3 kinase activation

Although 75% of endometrial cancers are treated at an early stage, 15% to 20% of these recur. We performed an integrated analysis of genome-wide expression and copy-number data for primary endometrial carcinomas with extensive clinical and histopathological data to detect features predictive of recurrent disease. Unsupervised analysis of the expression data distinguished 2 major clusters with strikingly different phenotypes, including significant differences in disease-free survival. To identify possible mechanisms for these differences, we performed a global genomic survey of amplifications, deletions, and loss of heterozygosity, which identified 11 significantly amplified and 13 significantly deleted regions. Amplifications of 3q26.32 harboring the oncogene PIK3CA were associated with poor prognosis and segregated with the aggressive transcriptional cluster. Moreover, samples with PIK3CA amplification carried signatures associated with in vitro activation of PI3 kinase (PI3K), a signature that was shared by aggressive tumors without PIK3CA amplification. Tumors with loss of PTEN expression or PIK3CA overexpression that did not have PIK3CA amplification also shared the PI3K activation signature, high protein expression of the PI3K pathway member STMN1, and an aggressive phenotype in test and validation datasets. However, mutations of PTEN or PIK3CA were not associated with the same expression profile or aggressive phenotype. STMN1 expression had independent prognostic value. The results affirm the utility of systematic characterization of the cancer genome in clinically annotated specimens and suggest the particular importance of the PI3K pathway in patients who have aggressive endometrial cancer.

Stathmin overexpression identifies high-risk patients and lymph node metastasis in endometrial cancer.

Purpose: Overexpression of the oncogen Stathmin has been linked to aggressive endometrial carcinoma and a potential for PI3Kinase inhibitors in this disease. We wanted to validate the prognostic value of Stathmin expression in a large prospective multicenter setting. As lymph node sampling is part of current surgical staging, we also aimed to test if Stathmin expression in endometrial curettage specimens could predict lymph node metastasis. Experimental Design: A total of 1,076 endometrial cancer patients have been recruited from 10 centers to investigate the biological tumor marker Stathmin in relation to clinicopathologic variables, including lymph node status and survival. Stathmin immunohistochemical staining was carried out in 477 hysterectomy and 818 curettage specimens. Results: Seventy-one percent of the patients (n = 763) were subjected to lymph node sampling, of which 12% had metastatic nodes (n = 94). Overexpression of Stathmin was detected in 37% (302 of 818) of the curettage and in 18% (84 of 477) of the hysterectomy specimens investigated. Stathmin overexpression in curettage and hysterectomy specimens were highly correlated and significantly associated with nonendometrioid histology, high grade, and aneuploidy. Stathmin analysis in preoperative curettage samples significantly correlated with, and was an independent predictor of, lymph node metastases. High Stathmin expression was associated with poor disease-specific survival (P ≤ 0.002) both in curettage and hysterectomy specimens. Conclusions: Stathmin immunohistochemical staining identifies endometrial carcinomas with lymph node metastases and poor survival. The value, as a predictive marker for response to PI3Kinase inhibition and as a tool to stratify patients for lymph node sampling in endometrial carcinomas, remains to be determined. Clin Cancer Res; 17(10); 3368–77. ©2011 AACR.

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.

Hormone receptor loss in endometrial carcinoma curettage predicts lymph node metastasis and poor outcome in prospective multicentre trial

BACKGROUND Preoperative histologic examination of tumour tissue is essential when deciding if endometrial cancer surgery should include lymph node sampling. We wanted to investigate if biomarkers could improve prediction of lymph node metastasis and outcome. PATIENTS AND METHODS Curettage specimens from 832 endometrial carcinoma patients prospectively recruited from 10 centres in the MoMaTEC trial (Molecular Markers in Treatment of Endometrial Cancer) were investigated for hormone receptor and p53 status. RESULTS Eighteen per cent of tumours were double negative for oestrogen- and progesterone receptors (ER/PR loss), 24% overexpressed p53. Pathologic expression of all markers correlated with nodal metastases, high FIGO (Federation International of Gynecology and Obstetrics) stage, non-endometrioid histology, high grade and poor prognosis (all P<0.001). ER/PR loss independently predicted lymph node metastasis (odds ratios (OR) 2.0, 95% confidence interval (CI) 1.1-3.7) adjusted for preoperative curettage histology and predicted poor disease-specific survival adjusted for age, FIGO stage, histologic type, grade and myometrial infiltration (hazard ratio (HR) 2.3, 95% CI 1.4-3.9). For lymph node negative endometrioid tumours, ER/PR loss influenced survival independent of grade. CONCLUSION Double negative hormone receptor status in endometrial cancer curettage independently predicts lymph node metastasis and poor prognosis in a prospective multicentre setting. Implementing hormone receptor status to improve risk-stratification for selecting patients unlikely to benefit from lymphadenectomy seems justified.

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.

Molecular profiling of circulating tumor cells links plasticity to the metastatic process in endometrial cancer

BackgroundAbout 20% of patients diagnosed with endometrial cancer (EC) are considered high-risk with unfavorable prognosis. In the framework of the European Network for Individualized Treatment in EC (ENITEC), we investigated the presence and phenotypic features of Circulating Tumor Cells (CTC) in high-risk EC patients.MethodsCTC isolation was carried out in peripheral blood samples from 34 patients, ranging from Grade 3 Stage IB to Stage IV carcinomas and recurrences, and 27 healthy controls using two methodologies. Samples were subjected to EpCAM-based immunoisolation using the CELLection™ Epithelial Enrich kit (Invitrogen, Dynal) followed by RTqPCR analysis. The phenotypic determinants of endometrial CTC in terms of pathogenesis, hormone receptor pathways, stem cell markers and epithelial to mesenchymal transition (EMT) drivers were asked. Kruskal-Wallis analysis followed by Dunn’s post-test was used for comparisons between groups. Statistical significance was set at p < 0.05.ResultsEpCAM-based immunoisolation positively detected CTC in high-risk endometrial cancer patients. CTC characterization indicated a remarkable plasticity phenotype defined by the expression of the EMT markers ETV5, NOTCH1, SNAI1, TGFB1, ZEB1 and ZEB2. In addition, the expression of ALDH and CD44 pointed to an association with stemness, while the expression of CTNNB1, STS, GDF15, RELA, RUNX1, BRAF and PIK3CA suggested potential therapeutic targets. We further recapitulated the EMT phenotype found in endometrial CTC through the up-regulation of ETV5 in an EC cell line, and validated in an animal model of systemic dissemination the propensity of these CTC in the accomplishment of metastasis.ConclusionsOur results associate the presence of CTC with high-risk EC. Gene-expression profiling characterized a CTC-plasticity phenotype with stemness and EMT features. We finally recapitulated this CTC-phenotype by over-expressing ETV5 in the EC cell line Hec1A and demonstrated an advantage in the promotion of metastasis in an in vivo mouse model of CTC dissemination and homing.

Elevated Plasma Growth Differentiation Factor-15 Correlates with Lymph Node Metastases and Poor Survival in Endometrial Cancer

Purpose: The study objective was to investigate and validate plasma growth differentiation factor-15 (GDF-15) as a predictor of lymph node metastasis and a poor prognosis in primary endometrial cancer. Experimental Design: Plasma samples from 510 women treated for endometrial cancer in a primary investigation cohort (n = 44) and a secondary validation cohort (n = 466) were analyzed for GDF-15. Plasma from healthy premenopausal (n = 20) and postmenopausal (n = 20) women, women with borderline (n = 43), benign (n = 144), and malignant ovarian tumors (n = 125) were used for comparison. Results: Median plasma GDF-15 concentration for the endometrial cancer group was elevated (1,077 ng/L) as compared with pre- and postmenopausal controls (590 and 684 ng/L) and women with benign (591 ng/L) or borderline ovarian tumors (718 ng/L; all P < 0.001), but similar to the ovarian cancer group. In the large validation cohort of endometrial carcinomas, high plasma GDF-15 was significantly associated with International Federation of Gynecology and Obstetrics (FIGO) stage III/IV disease, nonendometrioid histology, high grade, older age, postmenopausal status, and lymph node metastases (all P ≤ 0.001). High GDF-15 was also an independent predictor of poor disease-specific and recurrence-free survival. Conclusions: Based on findings indicated in a primary investigation set and confirmed in the large secondary validation set, we report for the first time plasma GDF-15 as a biomarker for endometrial cancer phenotype, including presence of lymph node metastasis and reduced survival. Its applicability as a predictor of metastatic nodes and in monitoring treatment of endometrial cancer needs to be further studied. Clin Cancer Res; 17(14); 4825–33. ©2011 AACR.

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.