title: Krüppel-like factor 8 (KLF8) is expressed in gliomas of different WHO grades and is essential for tumor cell proliferation.
abstract: Krüppel-like factor 8 (KLF8) has only recently been identified to be involved in tumor cell proliferation and invasion of several different tumor entities like renal cell carcinoma, hepatocellular carcinoma and breast cancer. In the present study, we show for the first time the expression of KLF8 in gliomas of different WHO grades and its functional impact on glioma cell proliferation. In order to get information about KLF8-mRNA regulation qPCR was performed and did not reveal any significant difference in samples (n = 10 each) of non-neoplastic brain (NNB), low-grade gliomas (LGG, WHO°II) and glioblastomas (GBM, WHO°IV). Immunohistochemistry of tissue samples (n = 7 LGG, 11 AA and 12 GBM) did not show any significant difference in the fraction of KLF8-immunopositive cells of all analyzed cells in LGG (87%), AA (80%) or GBM (89%). Tissue samples from cerebral breast cancer metastasis, meningiomas but also non-neoplastic brain demonstrated comparable relative cell counts as well. Moreover, there was no correlation between KLF8 expression and the expression pattern of the assumed proliferation marker Ki67, which showed high variability between different tumor grade (9% (LGG), 6% (AA) and 15% (GBM) of Ki67-immunopositive cells). Densitometric analysis of Western blotting revealed that the relative amount of KLF8-protein did also not differ between the highly aggressive and proliferative GBM (1.05) compared to LGG (0.93; p<0.05, studens t-test). As demonstrated for some other non-glial cancer entities, KLF8-knockdown by shRNA in U87-MG cells confirmed its functional relevance, leading to an almost complete loss of tumor cell proliferation. Selective blocking of KLF8 might represent a novel anti-proliferative treatment strategy for malignant gliomas. Yet, its simultaneous expression in non-proliferating tissues could hamper this approach.
authors.affiliation: Department of Neurosurgery, Klinikum der Ludwig-Maximilians-Universität München, Campus Grosshadern, Munich, Germany. Oliver.Schnell@med.uni-muenchen.de
authors.forename: Oliver
authors.initials: O
authors.lastname: Schnell
authors.forename: Alexander
authors.initials: A
authors.lastname: Romagna
authors.forename: Irene
authors.initials: I
authors.lastname: Jaehnert
authors.forename: Valerie
authors.initials: V
authors.lastname: Albrecht
authors.forename: Sabina
authors.initials: S
authors.lastname: Eigenbrod
authors.forename: Kathrin
authors.initials: K
authors.lastname: Juerchott
authors.forename: Hans
authors.initials: H
authors.lastname: Kretzschmar
authors.forename: Jörg-Christian
authors.initials: JC
authors.lastname: Tonn
authors.forename: Christian
authors.initials: C
authors.lastname: Schichor
mesh_terms: D000328:Adult; D000368:Aged; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics / Q000502:physiology; D005909:Glioblastoma / Q000235:genetics / Q000378:metabolism; D005910:Glioma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D051741:Kruppel-Like Transcription Factors; D008297:Male; D008875:Middle Aged; D034741:RNA, Small Interfering; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D055815:Young Adult
chemical_list: C507402:KLF8 protein, human; D051741:Kruppel-Like Transcription Factors; D034741:RNA, Small Interfering; D012097:Repressor Proteins