In this study we investigated the expression of COX-1, COX-2 and COX-3
mRNA in C6
glioblastoma and normal brain tissues and the effects of
acetaminophen,
indomethacin or
metamizole treatments on the development of C6
glioblastoma in relation with COX inhibition.
Glioblastoma cells were inoculated intracerebrally into frontal lobe of adult male Wistar albino rats. 10 days after inoculation, rats were treated with 150 mg/kg
acetaminophen, 10 mg/kg
indomethacin or 150 mg/kg
metamizole. The
tumor size was measured histologically and total
RNA was isolated from
tumor or normal brain tissue and
mRNA levels of COX
isoforms were determined by qRT-PCR. Our results showed the presence of COX-1, COX-2 and COX-3 expressions in both C6
glioblastoma and normal brain tissues. In
tumor tissues COX-3 expression was significantly higher than normal brain tissue (p < 0.05) while there was no significant difference in COX-1 and COX-2 expressions.
Acetaminophen and
indomethacin decreased the
tumor size by 71 and 43 % by inhibiting COX-3
mRNA expression around 87 and 91 % respectively. For the first time our study proposes a possible relationship between COX-3
mRNA expression and C6
glioblastoma development. We also suggested that the inhibition of
COX-3 enzyme may be responsible for decrease in
tumor size in part, the mechanism by which
acetaminophen and
indomethacin decreased rat C6
glioblastoma growth. However, the molecular events responsible for COX-3 effects on
tumor development are still unresolved as these drugs exert their anti-
cancer effect via both COX-3 dependent and independent mechanisms.