Branavan Manoranjan and Sheila K. Singh
Hideo Nakamura, Keishi Makino, Masato Kochi, Yukitaka Ushio and Jun-ichi Kuratsu
The authors evaluated the effectiveness of a neoadjuvant therapy (NAT) consisting of combined chemoand radiotherapy followed by complete resection of the residual tumor in patients with nongerminomatous malignant germ cell tumors (NGMGCTs).
The authors treated 14 consecutive patients in whom NGMGCTs were diagnosed based on elevated levels of the tumor markers α-fetoprotein, human chorionic gonadotropin, and the β-subunit of human chorionic gonadotropin (β-HCG). Chemotherapy and radiotherapy were performed, and after the serum tumor markers level was in the normal or near-normal range, the residual tumors were completely resected.
Residual tumors were confirmed in 11 of the 14 patients after NAT, and total removal was successful in 10 of the 11 patients. In the other patient the residual tumor could not be completely excised because it was attached to a deep vein. The follow-up duration ranged from 1.2 to 22.2 years. The 5-year event-free and total survival rates were 86% and 93%, respectively. Although 3 patients died, 2 of tumor recurrence and 1 of a radiation-induced secondary tumor (glioblastoma), the other 11 are alive and without evidence of tumor recurrence.
The authors consider their NAT protocol for NGMGCT to be highly effective in relation to survival for the patients with NGMGCT, but there are several quality of life issues that need to be resolved.
Naoki Shinojima, Hideo Nakamura, Masayoshi Tasaki, Kouki Kameno, Shigeo Anai, Ken-ichi Iyama, Yukio Ando, Hiroshi Seto and Jun-ichi Kuratsu
Medulloblastoma is the most frequent malignant brain tumor of the posterior fossa in children and is considered an embryonal tumor. It has been suggested that medulloblastomas be categorized into 4 distinct molecular subgroups— WNT (DKK1), SHH (SFRP1), Group 3 (NPR3), or Group 4 (KCNA1)—since each subgroup is distinct and there is no overlap. The authors report on a 13-year-old boy with medulloblastoma. He presented with sudden-onset nausea and vomiting due to intratumoral hemorrhage. The medulloblastoma was thought to be in an early developmental stage because the tumor volume was extremely small. Immunohistochemical analysis showed that the tumor was mainly composed of DKK1- and NPR3-positive areas. The individual areas of the tumor stained only for DKK1 or NPR3, with no overlap—that is, DKK1 and NPR3 expression were mutually exclusive. Samples obtained by laser microdissection of individual areas and subjected to mass spectrometry confirmed that the expression patterns of proteins were different. Fluorescence in situ hybridization for chromosome 6 showed there were 2 distinct types of cells that exhibited monosomy or disomy of chromosome 6. These results demonstrated that distinct subtypes of medulloblastoma may be present within a single tumor, an observation that has not been previously reported. Our findings in this case indicate that early-stage medulloblastoma may include more than 1 distinct subtype and hint at factors involved in the origin and development of medulloblastomas.
Takanori Kamiryo, Kenji Tada, Shoji Shiraishi, Naoki Shinojima, Hideo Nakamura, Masato Kochi, Jun-ichi Kuratsu, Hideyuki Saya and Yukitaka Ushio
Object. One of the most frequent genetic abnormalities found in patients with glioblastoma multiforme (GBM) is homozygous deletion of the p16 tumor suppressor gene. The authors investigated whether this deletion is associated with prognosis in patients with GBM.
Methods. In 46 adult patients with supratentorial GBM, homozygous deletion of the p16 gene in tumor DNA was examined using the multiplex polymerase chain reaction assay. The deletion was confirmed in 14 (30.4%) of 46 patients, eight (30.8%) of 26 men and six (30.0%) of 20 women. Cox proportional hazard regression analysis, adjusted for age at surgery, the Karnofsky Performance Scale score, extent of resection, and the MIB-1 labeling index, revealed that homozygous deletion of the p16 gene was significantly associated with overall survival and progression-free survival in men, but not in women.
Conclusions. The results of this study suggest that p16 homozygous deletion is a significant unfavorable prognostic factor in male patients with GBM.
Mareina Kudo, Hirofumi Jono, Satoru Shinriki, Shigetoshi Yano, Hideo Nakamura, Keishi Makino, Takuichiro Hide, Daisuke Muta, Mitsuharu Ueda, Kazutoshi Ota, Yukio Ando and Jun-ichi Kuratsu
Interleukin-6 (IL-6) is a pleiotropic cytokine that regulates diverse physiological functions, including cell proliferation and survival. Recent studies have shown that IL-6 expression is often elevated in response to several types of glioma. Although IL-6 is said to play an important role in glioma, the involvement of IL-6 signaling has been quite controversial. The aim of this study was to evaluate the involvement of IL-6 signaling in glioma and the inhibitory effect of IL-6 signaling on glioma tumor proliferation.
The expression of IL-6 receptors (IL-6Rs) was evaluated in glioma tissues by means of immunohistochemical analysis, and the involvement of IL-6 signaling in glioblastoma multiforme (GBM) U87MG cell proliferation was also determined. In addition, to examine the inhibitory effect of IL-6 signaling on glioma cell proliferation, the authors investigated the effects of tocilizumab, the humanized anti–human IL-6R antibody in U87MG cells.
Increased immunoreactivity for IL-6R was predominantly found in the cytoplasm of endothelial cells in all GBM samples. Inhibition of IL-6 signaling by both IL-6– and IL-6R–specific small interfering RNA and AG490, a specific inhibitor of JAK2 phosphorylation, suppressed glioma cell proliferation. Furthermore, tocilizumab, a clinically developed humanized anti–human IL-6R antibody, exerted an antiproliferative effect on cells from the GBM cell line U87MG via the IL-6R–dependent JAK-STAT3 pathway.
The IL-6 signaling pathway plays an important role in glioma cell proliferation, and tocilizumab exerts an antitumor effect in U87MG glioma cells. These results may bring new insight into the molecular pathogenesis of glioma and may lead to a new therapeutic intervention.