title: MicroRNA expression profiles distinguish liposarcoma subtypes and implicate miR-145 and miR-451 as tumor suppressors.
abstract: Liposarcomas are rare, heterogeneous and malignant tumors that can be divided into four histological subtypes with different characteristics and clinical behavior. Treatment consists of surgery in combination with systemic chemotherapy, but nevertheless mortality rates are high. More insight into the biology of liposarcoma tumorigenesis is needed to devise novel therapeutic approaches. MicroRNAs (miRNAs) have been associated with carcinogenesis in many tumors and may function as tumor suppressor or oncogene. In this study we examined miRNA expression in an initial series of 57 human liposarcomas (including all subtypes), lipomas and normal fat by miRNA microarrays. Supervised hierarchical clustering of the most differentially expressed miRNAs (p < 0.0002) distinguished most liposarcoma subtypes and control tissues. The distinction between well differentiated liposarcomas and benign lipomas was blurred, suggesting these tumor types may represent a biological continuum. MiRNA signatures of liposarcoma subtypes were established and validated in an independent series of 58 liposarcomas and control tissues. The expression of the miR-143/145 and miR-144/451 cluster members was clearly reduced in liposarcomas compared to normal fat. Overexpression of miR-145 and miR-451 in liposarcoma cell lines decreased cellular proliferation rate, impaired cell cycle progression and induced apoptosis. In conclusion, we show that miRNA expression profiling can be used to discriminate liposarcoma subtypes, which can possibly aid in objective diagnostic decision making. In addition, our data indicate that miR-145 and miR-451 act as tumor suppressors in adipose tissue and show that re-expression of these miRNAs could be a promising therapeutic strategy for liposarcomas.
authors.affiliation: Department of Medical Oncology, Erasmus MC Cancer Institute, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Caroline M M
authors.initials: CM
authors.lastname: Gits
authors.forename: Patricia F
authors.initials: PF
authors.lastname: van Kuijk
authors.forename: Moniek B E
authors.initials: MB
authors.lastname: Jonkers
authors.forename: Antonius W M
authors.initials: AW
authors.lastname: Boersma
authors.forename: Marcel
authors.initials: M
authors.lastname: Smid
authors.forename: Wilfred F
authors.initials: WF
authors.lastname: van Ijcken
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Coindre
authors.forename: Fréderic
authors.initials: F
authors.lastname: Chibon
authors.forename: Cornelis
authors.initials: C
authors.lastname: Verhoef
authors.forename: Ron H J
authors.initials: RH
authors.lastname: Mathijssen
authors.forename: Michael A
authors.initials: MA
authors.lastname: den Bakker
authors.forename: Jaap
authors.initials: J
authors.lastname: Verweij
authors.forename: Stefan
authors.initials: S
authors.lastname: Sleijfer
authors.forename: Erik A C
authors.initials: EA
authors.lastname: Wiemer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D016000:Cluster Analysis; D005260:Female; D005434:Flow Cytometry; D016147:Genes, Tumor Suppressor; D006801:Humans; D008080:Liposarcoma / Q000235:genetics* / Q000473:pathology*; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D059467:Transcriptome; D014162:Transfection
chemical_list: C541010:MIRN145 microRNA, human; C531201:MIRN451 microRNA, human; D035683:MicroRNAs
keywords: liposarcoma; miR-145; miR-451; microRNA; tumor suppressors