Search

// Geir Bredholt 1, * , Monica Mannelqvist 1, * , Ingunn M. Stefansson 1, 2 , Even Birkeland 1 , Trond Hellem Bo 1, 3 , Anne M. Oyan 4, 5 , Jone Trovik 5, 6 , Karl-Henning Kalland 4, 5 , Inge Jonassen 3 , Helga B. Salvesen 5, 6 , Elisabeth Wik 1, 2 , Lars A. Akslen 1, 2 1 Centre for Cancer Biomarkers CCBIO, Department of Clinical Medicine, Section for Pathology, University of Bergen, Bergen, Norway 2 Department of Pathology, Haukeland University Hospital, Bergen, Norway 3 CCBIO, Department of Informatics, University of Bergen, Bergen, Norway 4 Department of Microbiology, Haukeland University Hospital, Bergen, Norway 5 Center for Cancer Biomarkers CCBIO, Department of Clinical Science, University of Bergen, Norway 6 Department of Gynecology and Obstetrics, Haukeland University Hospital, Bergen, Norway * These authors have contributed equally to this work Correspondence to: Lars A. Akslen, e-mail: lars.akslen@uib.no Keywords: necrosis, hypoxia, angiogenesis, inflammation, gene signatures Received: June 11, 2015 Accepted: August 26, 2015 Published: October 14, 2015 ABSTRACT 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.

// Ingunn M. Stefansson 1,2,* , Maria Raeder 1,3,* , Elisabeth Wik 1,2 , Monica Mannelqvist 1,2 , Kanthida Kusonmano 1,3 , Goril Knutsvik 1,2 , Ingfrid Haldorsen 4,5 , Jone Trovik 1,3 , Anne M. Oyan 1,6 , Karl-H. Kalland 1,6 , Anne Cathrine Staff 7 , Helga B. Salvesen 1,3 and Lars A. Akslen 1,2 1 Centre for Cancer Biomarkers CCBIO, Department of Clinical Medicine, Section for Pathology, University of Bergen, Bergen, Norway 2 Department of Pathology, Haukeland University Hospital, Bergen, Norway 3 Department of Obstetrics and Gynaecology, Haukeland University Hospital, Bergen, Norway 4 Department of Radiology, Haukeland University Hospital, Postbox, Bergen, Norway 5 Section for Radiology, University of Bergen, Bergen, Norway 6 Department of Microbiology, Haukeland University Hospital, Bergen, Norway 7 Department of Obstetrics and Gynaecology, Women and Children’s Division, Oslo University Hospital, University of Oslo, Norway * These authors contributed equally to this work Correspondence to: Lars A. Akslen, email: // Keywords : angiogenesis, endometrial cancer, gene expression signature, prognosis Received : January 19, 2015 Accepted : February 17, 2015 Published : March 10, 2015 Abstract Background: Angiogenesis is a hallmark of cancer. The aim of this study was to explore whether microvessel proliferation is associated with gene expression profiles or copy number alterations in endometrial cancer. Methods: A prospective series of endometrial carcinomas was studied for angiogenesis markers, gene expression profiles, and gene copy number data. For validation, an independent series of endometrial carcinomas as well as an external cohort of endometrial cancer patients were examined by gene expression microarrays. Results: Increased microvessel proliferation (MVP) was associated with aggressive tumor features and reduced survival, and a 32-gene expression signature was found to separate tumors with high versus low MVP. An increased 32-gene signature score was confirmed to associate with high-grade tumor features and reduced survival by independent cohorts. Copy number studies revealed that amplification of the 6p21 region was significantly associated with MVP, a high 32-gene score, as well as reduced survival. Conclusion: Increased MVP was significantly associated with aggressive endometrial cancer and reduced survival. Integrated analyses demonstrated significant associations between increased vascular proliferation, amplification of the 6p21 region, VEGF-A mRNA expression, and the 32-gene angiogenesis signature. Our findings indicate amplification of 6p21 as a possible driver of tumor vascular proliferation in endometrial cancer.

Obesity is linked to increased incidence of endometrioid endometrial cancer (EEC) and complex atypical hyperplasia (CAH). We here explore pattern and sequence of molecular alterations characterizing endometrial carcinogenesis in general and related to body mass index (BMI), to improve diagnostic stratification and treatment strategies. We performed molecular characterization of 729 prospectively collected EEC and CAH. Candidate biomarkers were identified in frozen samples by whole-exome and Sanger sequencing, oligonucleotide gene expression and Reverse Phase Protein Arrays (investigation cohort) and further explored in formalin fixed tissues by immunohistochemistry and Fluorescent in Situ Hybridization (validation cohort). We here demonstrate that PIK3CA mutations, PTEN loss, PI3K and KRAS activation are early events in endometrial carcinogenesis. Molecular changes related to KRAS activation and inflammation are more common in obese CAH patients, suggesting different prevention and systemic treatment strategies in obese and non-obese patients. We also found that oncoprotein Stathmin might improve preoperative diagnostic distinction between premalignant and malignant endometrial lesions.

Cancers arise through accumulating genetic and epigenetic alterations, considered relevant for phenotype and approaches to targeting new therapies. We investigated a unique collection of endometrial cancer precursor samples and clinically annotated primary and metastatic lesions for two evolutionary and functionally related transcription factors, CCCTC-binding factor (zinc finger protein) (CTCF) and its paralogue CTCF-like factor, also denoted Brother of the Regulator of Imprinted Sites (CTCFL/BORIS). CTCF, a chromatin modeling- and transcription factor, is normally expressed in a ubiquitous fashion, while CTCFL/BORIS is restricted to the testis. In cancer, CTCF is thought to be a tumor suppressor, while CTCFL/BORIS has been suggested as an oncogene. CTCF mutations were identified in 13 %, with CTCF hotspot frameshift mutations at p.T204, all observed solely in the endometrioid subtype, but with no association with outcome. Interestingly, CTCFL/BORIS was amongst the top ranked genes differentially expressed between endometrioid and non-endometrioid tumors, and increasing mRNA level of CTCFL/BORIS was highly significantly associated with poor survival. As aberrant CTCFL/BORIS expression might relate to loss of methylation, we explored methylation status in clinical samples from complex atypical hyperplasia, through primary tumors to metastatic lesions, demonstrating a pattern of DNA methylation loss during disease development and progression in line with the increase in CTCFL/BORIS mRNA expression observed. Thus, CTCF and CTCFL/BORIS are found to diverge in the different subtypes of endometrial cancer, with CTCFL/BORIS activation through demethylation from precursors to metastatic lesions. We thus propose, CTCFL/BORIS as an Epi-driver gene in endometrial cancer, suggesting a potential for future vaccine development.