Clinical relevance of cytoskeleton associated proteins for ovarian cancer
JOURNAL OF CANCER RESEARCH AND CLINICAL ONCOLOGY
Authors: Schiewek, Johanna; Schumacher, Udo; Lange, Tobias; Joosse, Simon A.; Wikman, Harriet; Pantel, Klaus; Mikhaylova, Marina; Kneussel, Matthias; Linder, Stefan; Schmalfeldt, Barbara; Oliveira-Ferrer, Leticia; Windhorst, Sabine
Abstract
PurposeOvarian cancer has a high mortality rate and up to now no reliable molecular prognostic biomarkers have been established. During malignant progression, the cytoskeleton is strongly altered. Hence we analyzed if expression of certain cytoskeleton-associated proteins is correlated with clinical outcome of ovarian cancer patients.MethodsFirst, in silico analysis was performed using the cancer genome atlas (TCGA), the human expression atlas and Pubmed. Selected candidates were validated on 270 ovarian cancer patients by qRT-PCR and/or by western blotting.ResultsIn silico analysis revealed that mRNAs of 214 cytoskeleton-associated proteins are detectable in ovarian cancer tissue. Among these, we selected 17 proteins that participate in cancer disease progression and cytoskeleton modulation: KIF14, KIF20A, KIF18A, ASPM, CEP55, DLGAP5, MAP9, EB1, KATNA1, DIAPH1, ANLN, SCIN, CCDC88A, FSCN1, GSN, VASP and CDC42. The first ten candidates interact with microtubules (MTs) and the others bind to actin filaments. Validation on clinical samples of ovarian cancer patients revealed that the expression levels of DIAPH1, EB1, KATNA1, KIF14 and KIF18A significantly correlated with clinical and histological parameters of ovarian cancer. High DIAPH1, EB1, KATNA1 and KIF14 protein levels were associated with increased overall survival (OAS) of ovarian cancer patients, while high DIAPH1 and EB1 protein levels were also associated with low differentiation of respective tumors (G2/3). Moreover, DIAPH1 was the only protein, whose expression significantly correlated with increased recurrence-free interval (RFI).ConclusionMainly the expression levels of the MT-associated proteins analyzed in this study, correlated with prolonged survival of ovarian cancer patients. From >200 genes initially considered, 17 cytoskeletal proteins are involved in cancer progression according to the literature. Among these, four proteins significantly correlated with improved survival of ovarian cancer patients.
Fusion genes with ALK as recurrent partner in ependymoma-like gliomas: a new brain tumor entity?
NEURO-ONCOLOGY
Authors: Olsen, Thale Kristin; Panagopoulos, Ioannis; Meling, Torstein R.; Micci, Francesca; Gorunova, Ludmila; Thorsen, Jim; Due-Tonnessen, Bernt; Scheie, David; Lund-Iversen, Marius; Krossnes, Bard; Saxhaug, Cathrine; Heim, Sverre; Brandal, Petter
Abstract
Background. We have previously characterized 19 ependymal tumors using Giemsa banding and high-resolution comparative genomic hybridization. The aim of this study was to analyze these tumors searching for fusion genes. Methods. RNA sequencing was performed in 12 samples. Potential fusion transcripts were assessed by seed count and structural chromosomal aberrations. Transcripts of interest were validated using fluorescence in situ hybridization and PCR followed by direct sequencing. Results. RNA sequencing identified rearrangements of the anaplastic lymphoma kinase gene (ALK) in 2 samples. Both tumors harbored structural aberrations involving the ALK locus 2p23. Tumor 1 had an unbalanced t(2;14)( p23;q22) translocation which led to the fusion gene KTN1-ALK. Tumor 2 had an interstitial del(2)(p16p23) deletion causing the fusion of CCDC88A and ALK. In both samples, the breakpoint of ALK was located between exons 19 and 20. Both patients were infants and both tumors were supratentorial. The tumors were well demarcated from surrounding tissue and had both ependymal and astrocytic features but were diagnosed and treated as ependymomas. Conclusions. By combining karyotyping and RNA sequencing, we identified the 2 first ever reported ALK rearrangements in CNS tumors. Such rearrangements may represent the hallmark of a new entity of pediatric glioma characterized by both ependymal and astrocytic features. Our findings are of particular importance because crizotinib, a selective ALK inhibitor, has demonstrated effect in patients with lung cancer harboring ALK rearrangements. Thus, ALK emerges as an interesting therapeutic target in patients with ependymal tumors carrying ALK fusions.