title: Expression of PROX1 Is a common feature of high-grade malignant astrocytic gliomas.
abstract: PROX1 is a prospero-related transcription factor that plays a critical role in the development of various organs including the mammalian lymphatic and central nervous systems; it controls cell proliferation and differentiation through different transcription pathwaysand has both oncogenic and tumor-suppressive functions. We investigated PROX1 expression patterns in 56 human astrocytic gliomas of different grades using immunohistochemistry. An average of 79% of cells in World Health Organization Grade IV (glioblastoma, n = 15) and 57% of cells in World Health Organization Grade III (anaplastic astrocytoma, n = 13) were strongly PROX1 positive; low-grade diffuse astrocytomas (Grade II, n = 13) had 21% of cells that were strongly positive; Grade I tumors (n = 15) had 1.5%; and non-neoplastic brain tissue (n = 15) had 3.7% of cells that were PROX1 positive. Double immunolabeling showed that PROX1+ cells in glioblastomas frequently coexpressed early neuronal proteins MAP2 and betaIII-tubulin but not the mature neuronal marker protein NeuN. Analyses of coexpression with proliferation markers suggest that PROX1+ cells have a marginally lower rate of proliferation than other tumor cells but are still mitotically active. We conclude that PROX1 may constitute a useful tool for the diagnosis and grading ofastrocytic gliomas and for distinguishing Grade III and Grade IV tumors from Grade I and Grade II tumors.
authors.affiliation: Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Tamador
authors.initials: T
authors.lastname: Elsir
authors.forename: Anna
authors.initials: A
authors.lastname: Eriksson
authors.forename: Abiel
authors.initials: A
authors.lastname: Orrego
authors.forename: Mikael S
authors.initials: MS
authors.lastname: Lindström
authors.forename: Monica
authors.initials: M
authors.lastname: Nistér
mesh_terms: D034961:Antigens, Nuclear / Q000378:metabolism; D001254:Astrocytoma / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology*; D015415:Biomarkers / Q000378:metabolism; D001927:Brain Diseases / Q000378:metabolism; D001932:Brain Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology*; D049109:Cell Proliferation; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D055806:Microvessels / Q000378:metabolism; D008938:Mitosis; D009419:Nerve Tissue Proteins / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D000098551:Prospero-Related Homeobox 1 Protein
chemical_list: D034961:Antigens, Nuclear; D015415:Biomarkers; D018398:Homeodomain Proteins; C489788:MAP2 protein, human; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D014404:Tubulin; D025521:Tumor Suppressor Proteins; C506808:neuronal nuclear antigen NeuN, human; D000098551:Prospero-Related Homeobox 1 Protein