Abstract
Pineal parenchymal tumors (PPTs) are rare neoplasms which occupy less than 1% of primary CNS tumors. Because of their rare incidence, previous reports on PPTs are limited in number and the useful molecular markers for deciding histological grading and even selecting chemotherapy are undetermined. In this study, we conducted immunohistochemical analysis of 12 PPT specimens, especially for expression of O6-methylguanine DNA methyltransferase (MGMT) to assess whether temozolomide (TMZ) could serve as a possible alternative therapy for PPTs. We analyzed 12 PPTs, consisting of three pineocytomas, six PPTs of intermediate differentiation (PPTIDs), and three pineoblastomas. Immunohistochemical analysis was performed using antibodies against MGMT, synaptophysin, neurofilament protein (NF), p53, and neuronal nuclear antigen (NeuN). Immunohistochemically, 11 out of 12 cases were positive for MGMT. The mean MIB-1 labeling index was less than 1% in pineocytoma, 3.5% in PPTID, and 10.5% in pineoblastoma. All 12 cases were positive for synaptophysin and 11 cases, except one PPTID case, showed positive for NF. Nuclear staining of NeuN was negative in all cases although cytoplasmic staining of NeuN was observed in five cases. No case was positive for p53. Eleven out of 12 cases of PPTs demonstrated MGMT expression, suggesting chemoresistancy to TMZ treatment. This is the first report showing MGMT expression in PPTs. In addition, MIB-1 labeling index correlated with WHO grade, although the immunoreactivity of synaptophysin, NF, NeuN and p53 did not correlate with the histological grade.
| Original language | English |
|---|---|
| Pages (from-to) | 647-653 |
| Number of pages | 7 |
| Journal | Neuropathology |
| Volume | 32 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2012 Dec 1 |
| Externally published | Yes |
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Keywords
- Immunohistochemistry
- MGMT
- MIB-1
- Pinealoma
- Temozolomide
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Clinical Neurology
Cite this
Expression of O6-methylguanine DNA methyltransferase (MGMT) and immunohistochemical analysis of 12 pineal parenchymal tumors. / Kanno, Hiromi; Nishihara, Hiroshi; Oikawa, Mitsuteru; Ozaki, Yoshimaru; Murata, Junichi; Sawamura, Yutaka; Kato, Masahito; Kubota, Kanako; Tanino, Mishie; Kimura, Taichi; Nagashima, Kazuo; Itoh, Tamio; Tanaka, Shinya.
In: Neuropathology, Vol. 32, No. 6, 01.12.2012, p. 647-653.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Expression of O6-methylguanine DNA methyltransferase (MGMT) and immunohistochemical analysis of 12 pineal parenchymal tumors
AU - Kanno, Hiromi
AU - Nishihara, Hiroshi
AU - Oikawa, Mitsuteru
AU - Ozaki, Yoshimaru
AU - Murata, Junichi
AU - Sawamura, Yutaka
AU - Kato, Masahito
AU - Kubota, Kanako
AU - Tanino, Mishie
AU - Kimura, Taichi
AU - Nagashima, Kazuo
AU - Itoh, Tamio
AU - Tanaka, Shinya
PY - 2012/12/1
Y1 - 2012/12/1
N2 - Pineal parenchymal tumors (PPTs) are rare neoplasms which occupy less than 1% of primary CNS tumors. Because of their rare incidence, previous reports on PPTs are limited in number and the useful molecular markers for deciding histological grading and even selecting chemotherapy are undetermined. In this study, we conducted immunohistochemical analysis of 12 PPT specimens, especially for expression of O6-methylguanine DNA methyltransferase (MGMT) to assess whether temozolomide (TMZ) could serve as a possible alternative therapy for PPTs. We analyzed 12 PPTs, consisting of three pineocytomas, six PPTs of intermediate differentiation (PPTIDs), and three pineoblastomas. Immunohistochemical analysis was performed using antibodies against MGMT, synaptophysin, neurofilament protein (NF), p53, and neuronal nuclear antigen (NeuN). Immunohistochemically, 11 out of 12 cases were positive for MGMT. The mean MIB-1 labeling index was less than 1% in pineocytoma, 3.5% in PPTID, and 10.5% in pineoblastoma. All 12 cases were positive for synaptophysin and 11 cases, except one PPTID case, showed positive for NF. Nuclear staining of NeuN was negative in all cases although cytoplasmic staining of NeuN was observed in five cases. No case was positive for p53. Eleven out of 12 cases of PPTs demonstrated MGMT expression, suggesting chemoresistancy to TMZ treatment. This is the first report showing MGMT expression in PPTs. In addition, MIB-1 labeling index correlated with WHO grade, although the immunoreactivity of synaptophysin, NF, NeuN and p53 did not correlate with the histological grade.
AB - Pineal parenchymal tumors (PPTs) are rare neoplasms which occupy less than 1% of primary CNS tumors. Because of their rare incidence, previous reports on PPTs are limited in number and the useful molecular markers for deciding histological grading and even selecting chemotherapy are undetermined. In this study, we conducted immunohistochemical analysis of 12 PPT specimens, especially for expression of O6-methylguanine DNA methyltransferase (MGMT) to assess whether temozolomide (TMZ) could serve as a possible alternative therapy for PPTs. We analyzed 12 PPTs, consisting of three pineocytomas, six PPTs of intermediate differentiation (PPTIDs), and three pineoblastomas. Immunohistochemical analysis was performed using antibodies against MGMT, synaptophysin, neurofilament protein (NF), p53, and neuronal nuclear antigen (NeuN). Immunohistochemically, 11 out of 12 cases were positive for MGMT. The mean MIB-1 labeling index was less than 1% in pineocytoma, 3.5% in PPTID, and 10.5% in pineoblastoma. All 12 cases were positive for synaptophysin and 11 cases, except one PPTID case, showed positive for NF. Nuclear staining of NeuN was negative in all cases although cytoplasmic staining of NeuN was observed in five cases. No case was positive for p53. Eleven out of 12 cases of PPTs demonstrated MGMT expression, suggesting chemoresistancy to TMZ treatment. This is the first report showing MGMT expression in PPTs. In addition, MIB-1 labeling index correlated with WHO grade, although the immunoreactivity of synaptophysin, NF, NeuN and p53 did not correlate with the histological grade.
KW - Immunohistochemistry
KW - MGMT
KW - MIB-1
KW - Pinealoma
KW - Temozolomide
UR - http://www.scopus.com/inward/record.url?scp=84870063215&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84870063215&partnerID=8YFLogxK
U2 - 10.1111/j.1440-1789.2012.01315.x
DO - 10.1111/j.1440-1789.2012.01315.x
M3 - Article
VL - 32
SP - 647
EP - 653
JO - Neuropathology
JF - Neuropathology
SN - 0919-6544
IS - 6
ER -