The PFKFB3 splice variant UBI2K4 is downregulated in high-grade astrocytomas and impedes the growth of U87 glioblastoma cells.
Neuropathol Appl Neurobiol
; 35(6): 566-78, 2009 Dec.
Article
em En
| MEDLINE
| ID: mdl-19490427
ABSTRACT
AIMS:
Fructose-2,6-bisphosphate, a key regulator of glycolysis, is synthesized and degraded by four different isozymes of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB1-4). The PFKFB3 isozyme is upregulated in several human tumours. Six alternatively spliced variants of PFKFB3 mRNA are known in humans (UBI2K1-6). Here, we studied the role of the PFKFB3 splice variants in human astrocytic gliomas.METHODS:
We analysed the PFKFB3 splice variants in 48 astrocytic gliomas by RT-PCR and real-time PCR. The effect of transient and stable overexpression of the PFKFB3 isoforms was studied in U87 glioblastoma cells by MTT, cell counting, clone formation assay and metabolic measurements.RESULTS:
UBI2K5 and UBI2K6 are the predominant splice variants in rapidly proliferating high-grade astrocytomas while the expression of UBI2K3 and UBI2K4 is mainly restricted to low-grade astrocytomas and nonneoplastic brain tissue. Overexpression of UBI2K5 or UBI2K6 in the U87 glioblastoma cell line enhances the glycolytic flux but does not affect cell growth. In contrast, overexpression of UBI2K4 reduces cell viability and anchorage-independent growth of U87 cells. The UBI2K4 mRNA level is downregulated in astrocytic gliomas with increasing malignancy grade. Moreover, the UBI2K4 mRNA level correlates with growth rate of several human cancer cell lines derived from different tissue types.CONCLUSIONS:
Our results demonstrate that the splice variant UBI2K4 impedes the tumour cell growth and might serve as a tumour suppressor in astrocytic tumours.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Astrocitoma
/
Neoplasias Encefálicas
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Glioblastoma
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Fosfofrutoquinase-2
Limite:
Humans
Idioma:
En
Revista:
Neuropathol Appl Neurobiol
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Alemanha