6 research outputs found
Prognosis in human glioblastoma based on expression of ligand growth hormone-releasing hormone, pituitary-type growth hormone-releasing hormone receptor, its splicing variant receptors, EGF receptor and PTEN genes
Purpose G lioblastoma (GB) is the most frequent brain
tumor. Despite recent improvement in therapeutic strategies,
the prognosis of GB remains poor. Growth hormone-releasing
hormone (GHRH) may act as a growth factor; antagonists
of GHRH have been successfully applied for experimental
treatment of different types of tumors. The expression profile
of GHRH receptor, its main splice variant SV1 and GHRH
have not been investigated in human GB tissue samples.
Methods We examined the expression of GHRH, fulllength
pituitary-type GHRH receptor (pGHRHR), its functional
splice variant SV1 and non-functional SV2 by RTPCR
in 23 human GB specimens. Epidermal growth factor
receptor (EGFR) and phosphatase and tensin homolog gene
(PTEN) expression levels were also evaluated by quantitative
RT-PCR. Correlations between clinico-pathological
parameters and gene expressions were analyzed.
Results E xpression of GHRH was found to be positive
in 61.9 % of samples. pGHRH receptor was not expressed
in our sample set, while SV1 could be detected in 17.4 %
and SV2 in 8.6 % of the GB tissues. In 65.2 and 78.3 %
of samples, significant EGFR over-expression or PTEN
under-representation could be detected, respectively. In
47.8 % of cases, EGFR up-regulation and PTEN down-regulation
occurred together. Survival was significantly poorer
in tumors lacking GHRH expression. This worse prognosis
in GHRH negative group remained significant even if SV1
was also expressed.
Conclusion Our study shows that GHRH and SV1 genes
expressed in human GB samples and their expression patterns
are associated with poorer prognosis