Elevation of plasma and cerebrospinal fluid osteopontin levels in patients with atypical teratoid/rhabdoid tumor.

Osteopontin, a cancer metastasis-associated gene, is specifically up-regulated in central nervous system (CNS) atypical teratoid/rhabdoid tumor (AT/RT), but its biological behavior in the progression of CNS AT/RT has never been studied. We obtained plasma, cerebrospinal fluid (CSF), and brain tissue specimens from lobectomy or hemispherectomy samples from 39 patients (medulloblastoma, 16; AT/RT, 8; epilepsy, 6; hydrocephalus, 9). By enzyme-linked immunosorbent assay, the median osteopontin levels in plasma and CSF in AT/RT (852.0 and 1,175.0 ng/mL, respectively) were significantly higher than in medulloblastoma (492.5 and 524.5 ng/mL, respectively) and hydrocephalus and epilepsy (208.0 and 168.0 ng/mL, respectively) (P < .05). The results of real-time reverse transcriptase-polymerase chain reaction and immunohistochemical analysis demonstrated that osteopontin expression in AT/RT (n = 5) was significantly higher than in medulloblastoma (n = 8) samples. The differences in osteopontin expression in plasma, CSF, and tumor samples in AT/RT and medulloblastoma correlated with survival differences. In 5 patients with AT/RT, plasma osteopontin levels decreased after treatment but increased with relapse. Osteopontin might be a potential marker to aid in identifying AT/RT recurrence.