GCT-22. PROTEIN DEUBIQUITINATION PATHWAY IS A NOVEL THERAPEUTIC TARGET AGAINST MALIGNANT NON-GERMINOMATOUS CNS GERM CELL TUMORS

Abstract Central nervous system germ cell tumors (CNSGCTs) are rare intracranial neoplasm usually developed in adolescents and young adults. However, in East Asia including Japan, incidence of CNSGCTs is considerably higher compare with other regions of the world. Whereas germinomas generally respond to chemo-radiotherapy well, malignant subtypes of non-germinomatous germ cell tumors (NGGCT) are refractory, and development of novel therapy against NGGCTs is urgently needed. To develop a new therapeutic strategy against aggressive NGGCTs, we have investigated novel molecular targets for NGGCT treatment. We screened a total of 120 CNSGCT tumor tissues (including 55 NGGCT), which were registered to the Intracranial Germ Cell Tumor Consortium (iGCT), and discovered multiple mutations of a molecule that regulates protein ubiquitination and degradation specifically in NGGCT cases (5 of 55 cases; 1 immature teratoma, 3 mixed gem cell tumors, and 1 embryonal carcinoma). An in vitro ubiquitination assay revealed the mutations of this molecule discovered in NGGCT cases were loss of function mutations. Reduced expression of this molecule by knockdown in an established human seminoma cell line Tcam2 or a human yolk sac tumor cell line YST1, which was recently established in our institute, resulted in enhanced proliferation as well as upregulation of MEK-ERK activation. Importantly, treatment of these two GCT cell lines with reduced expression of this molecule by MEK inhibitor trametinib suppressed augmented proliferation of these cells. Taken together, these results suggest that protein ubiquitination-related pathways as well as MEK-ERK cascade may serve as a novel therapeutic target against NGGCTs.

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SPDR-06 PROTEIN DEUBIQUITINATION PATHWAY IS A NOVEL THERAPEUTIC TARGET AGAINST MALIGNANT CNS NON-GERMINOMATOUS GERM CELL TUMORS

Neuro-Oncology Advances ◽

10.1093/noajnl/vdz039.032 ◽

2019 ◽

Vol 1 (Supplement_2) ◽

pp. ii7-ii7

Author(s):

Arata Tomiyama ◽

Eita Uchida ◽

Tatsuya Kobayashi ◽

Kojiro Wada ◽

Kouichi Ichimura

Keyword(s):

Germ Cell ◽

Cell Line ◽

Therapeutic Target ◽

Germ Cell Tumors ◽

Tumor Cell Line ◽

Loss Of Function ◽

Novel Therapy ◽

Intracranial Germ Cell Tumor ◽

Protein Ubiquitination ◽

Novel Therapeutic

Abstract Central nervous system germ cell tumors (CNSGCTs) are rare intracranial neoplasm usually developed in adolescents and young adults. However, in East Asia including Japan, incidence of CNSGCTs is considerably higher compare with other regions of the world. Whereas germinomas generally respond to chemo-radiotherapy well, malignant subtypes of non-germinomatous germ cell tumors (NGGCT) are refractory, and development of novel therapy against NGGCTs is urgently needed. To develop a new therapeutic strategy against aggressive NGGCTs, we have investigated novel molecular targets for NGGCT treatment. We screened a total of 120 CNSGCT tumor tissues (including 55 NGGCT), which were registered to the Intracranial Germ Cell Tumor Consortium (iGCT), and discovered multiple mutations of a molecule that regulates protein ubiquitination and degradation specifically in NGGCT cases (5 of 55 cases; 1 immature teratoma, 3 mixed gem cell tumors, and 1 embryonal carcinoma). An in vitro ubiquitination assay revealed the mutations of this molecule discovered in NGGCT cases were loss of function mutations. Reduced expression of this molecule by knockdown in an established human seminoma cell line Tcam2 or a human yolk sac tumor cell line YST1, which was recently established in our institute, resulted in enhanced proliferation as well as upregulation of MEK-ERK activation. Importantly, treatment of these two GCT cell lines with reduced expression of this molecule by MEK inhibitor trametinib suppressed augmented proliferation of these cells. Taken together, these results suggest that protein ubiquitination-related pathways as well as MEK-ERK cascade may serve as a novel therapeutic target against NGGCTs.

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GCT-46. MULTI-KINASE INHIBITORS AS NOVEL THERAPEUTIC AGENTS AGAINST INTRACRANIAL NON-GERMINOMATOUS GERM CELL TUMORS

Neuro-Oncology ◽

10.1093/neuonc/noaa222.264 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii337-iii337

Author(s):

Eita Uchida ◽

Tatsuya Ozawa ◽

Masamichi Takahashi ◽

Ryo Nishikawa ◽

Koichi Ichimura ◽

...

Keyword(s):

Cell Death ◽

Tumor Cell ◽

Germ Cell ◽

Cell Line ◽

Kinase Inhibitors ◽

Germ Cell Tumors ◽

Tumor Cell Line ◽

Membrane Receptors ◽

Antitumor Effects ◽

Novel Therapeutic

Abstract Central nervous system germ cell tumors (CNS GCTs) are rare intracranial malignancies developing in adolescents and young adults which relatively frequently occur in East Asia region of the world including Japan. However, among CNS GCTs, non-germinomatous germ cell tumors (NGGCTs) are highly resistant to the current chemoradiotherapies, and the prognosis of CNS NGGCTs is still extremely poor. Therefore, development of novel therapeutic strategy against CNS NGGCTs is urgently needed. In this study, we screened small molecule inhibitors of kinases specifically targeting cell membrane receptors, such as receptor tyrosine kinases, and their related molecular signaling, which could effectively exert antitumor effects against NGGCT cells. As the NGGCT model cells, the Tcam2 cell, a mixed germ cell tumor cell line composed of germinoma and embryonal carcinoma components, and the YST1 cell, a novel yolk sac tumor cell line established in our institute, were used. As a result, effective induction of cell death in both cell lines was confirmed only by treatment with two multi-kinase inhibitors. Immunoblotting revealed these multi-kinase inhibitors suppressed activation of various kinases concurrently. Furthermore, these multi-kinase inhibitors also triggered cell death in the Tcam2 cell stably expressing mutant KIT, the most common oncogenic driver genes of CNS GCTs, suggesting that these inhibitors would be also effective against CNS GCTs harboring activated KIT mutants. In vivo studies of these multi-kinase inhibitors using CNS GCT xenografts are currently on going.

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GCT-15. INTEGRATED CLINICAL, HISTOPATHOLOGICAL, AND MOLECULAR DATA ANALYSIS OF 190 CENTRAL NERVOUS SYSTEM GERM CELL TUMORS FROM THE IGCT CONSORTIUM

Neuro-Oncology ◽

10.1093/neuonc/noaa222.235 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii330-iii331

Author(s):

Hirokazu Takami ◽

Koichi Ichimura ◽

Kohei Fukuoka ◽

Akitake Mukasa ◽

Nobuhito Saito ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Basal Ganglia ◽

Pineal Gland ◽

Germ Cell ◽

Prognostic Significance ◽

Germ Cell Tumors ◽

Molecular Data ◽

Molecular Heterogeneity ◽

Intracranial Germ Cell Tumor

Abstract BACKGROUND We integrated clinical, histopathological, and molecular data of central nervous system germ cell tumors to provide insights into their management. METHODS Data from the Intracranial Germ Cell Tumor Genome Analysis Consortium were reviewed. A total of 190 cases were classified as primary GCTs based on central pathological reviews. RESULTS All but one of the cases that were bifocal (neurohypophysis and pineal glands) and cases with multiple lesions including neurohypophysis or pineal gland were germinomas (34 of 35). Age was significantly higher in patients with germinoma than other histologies. Comparison between tumor marker and histopathological diagnoses showed that 18.2% of histopathologically diagnosed germinomas were marker-positive and 6.1% of non-germinomatous GCTs were marker-negative, suggesting a limitation in the utility of markers or histopathology alone using small specimens for diagnosis. Comparison between local and central histopathological diagnoses revealed a discordance of 12.7%. Discordance was significantly less frequent in biopsy cases, implying difficulty in detecting all histopathological components of heterogeneous GCTs. Germinomas at the typical sites (neurohypophysis or pineal gland) showed a better PFS than those at atypical sites (p=0.03). A molecular-clinical association study revealed frequent MAPK pathway mutations in males (51.4 vs 14.3 %, p=0.007), and PI3K/mTOR pathway mutations in basal ganglia cases (p=0.004). Basal ganglia cases also had frequent chromosomal losses. Some chromosomal aberrations (2q, 8q gain, 5q, 9p/q, 13q, 15q loss) showed potential prognostic significance. CONCLUSIONS These in-depth findings of this study regarding the clinical and molecular heterogeneity will increase our understanding of the pathogenesis of this enigmatic tumor.

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MPC-08 CLINICOPATHOLOGICAL ANALYSIS OF 12P GAIN IN INTRACRANIAL GERM CELL TUMORS

Neuro-Oncology Advances ◽

10.1093/noajnl/vdz039.105 ◽

2019 ◽

Vol 1 (Supplement_2) ◽

pp. ii23-ii23

Author(s):

Kaishi Satomi ◽

Hirokazu Takami ◽

Shintaro Fukushima ◽

Yoichi Nakazato ◽

Shota Tanaka ◽

...

Keyword(s):

Germ Cell ◽

Germ Cell Tumor ◽

Copy Number ◽

Mature Teratoma ◽

Methylation Status ◽

Germ Cell Tumors ◽

Copy Number Variations ◽

Cell Tumor ◽

Testicular Germ Cell ◽

Intracranial Germ Cell Tumor

Abstract BACKGROUND Gain of short arm of chromosome 12 (12p) is commonly observed in testicular germ cell tumors (tGCTs). 12p gain is also frequently seen in intracranial GCTs (iGCTs). However, little is known about the clinical significance of 12p gain in iGCTs. MATERIALS AND METHODS We have collected over 200 fresh frozen tissue samples of iGCTs through the Intracranial Germ Cell Tumor Genome Analysis Consortium in Japan. Firstly, we analyzed DNA methylation status in 83 iGCTs, 3 seminomas and 6 normal control samples using Infinium Human Methylation 450K BeadChip array (Illumina, CA). Idat files were processed using R (Version 3.5.3) and minfi package (1.30.0) to generate copy number variations. Compared with average genome-wide copy number level, 12p gain was determined. Then, 58 iGCTs with clinicopathological information were analyzed for progression-free survival (PFS) and overall survival (OS). Those tumors that consist of only either germinoma and/or mature teratoma components were classified as Favorable Histology (FH) and all the others that contains malignant histological components were classified as Unfavorable Histology (UFH). RESULT 12p gain was observed in 100% (3/3) of seminoma, 13.6% (3/22) of germinoma, 16.7% (1/6) of mature teratoma, 25% (1/4) of immature teratoma, 55% (11/20) of mixed germ cell tumor, 100% (4/4) of yolk sac tumor, 100% (1/1) of embryonal carcinoma, and 100% (1/1) of choriocarcinoma. In total, 44.6% (37/83) of iGCT showed 12p gain. Regarding histological classification, the 12p gain rate in UFH (72%, 18/25) was significantly higher than that in FH (12.1%, 4/33, P<0.01). Both PFS and OS were significantly worse in iGCTs with 12p gain (PFS: P=0.027, OS: P=0.0012). DISCUSSION 12p gain can be a molecular marker to predict prognosis and histological malignancy in iGCTs.

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Integrated clinical, histopathological, and molecular data analysis of 190 central nervous system germ cell tumors from the iGCT Consortium

Neuro-Oncology ◽

10.1093/neuonc/noz139 ◽

2019 ◽

Vol 21 (12) ◽

pp. 1565-1577 ◽

Cited By ~ 1

Author(s):

Hirokazu Takami ◽

Kohei Fukuoka ◽

Shintaro Fukushima ◽

Taishi Nakamura ◽

Akitake Mukasa ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Basal Ganglia ◽

Pineal Gland ◽

Germ Cell ◽

Prognostic Significance ◽

Germ Cell Tumors ◽

Molecular Data ◽

Molecular Heterogeneity ◽

Intracranial Germ Cell Tumor

Abstract Background We integrated clinical, histopathological, and molecular data of central nervous system germ cell tumors to provide insights into their management. Methods Data from the Intracranial Germ Cell Tumor Genome Analysis (iGCT) Consortium were reviewed. A total of 190 cases were classified as primary germ cell tumors (GCTs) based on central pathological reviews. Results All but one of the cases that were bifocal (neurohypophysis and pineal glands) and cases with multiple lesions including neurohypophysis or pineal gland were germinomas (34 of 35). Age was significantly higher in patients with germinoma than other histologies. Comparison between tumor marker and histopathological diagnoses showed that 18.2% of histopathologically diagnosed germinomas were marker positive and 6.1% of non-germinomatous GCTs were marker negative, suggesting a limitation in the utility of markers or histopathology alone using small specimens for diagnosis. Comparison between local and central histopathological diagnoses revealed a discordance of 12.7%. Discordance was significantly less frequent in biopsy cases, implying difficulty in detecting all histopathological components of heterogeneous GCTs. Germinomas at the typical sites (neurohypophysis or pineal gland) showed a better progression-free survival than those at atypical sites (P = 0.03). A molecular clinical association study revealed frequent mitogen-activated protein kinase (MAPK) pathway mutations in males (51.4% vs 14.3%, P = 0.007), and phosphatidylinositol-3 kinase/mammalian target of rapamycin (PI3K/mTOR) pathway mutations in basal ganglia cases (P = 0.004). Basal ganglia cases also had frequent chromosomal losses. Some chromosomal aberrations (2q, 8q gain, 5q, 9p/q, 13q, 15q loss) showed potential prognostic significance. Conclusions The in-depth findings of this study regarding clinical and molecular heterogeneity will increase our understanding of the pathogenesis of this enigmatic tumor.

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ARID1A Regulates Transcription and the Epigenetic Landscape via POLE and DMAP1 While ARID1A Deficiency or Pharmacological Inhibition Sensitizes Germ Cell Tumor Cells to ATR Inhibition

Cancers ◽

10.3390/cancers12040905 ◽

2020 ◽

Vol 12 (4) ◽

pp. 905 ◽

Cited By ~ 2

Author(s):

Lukas Kurz ◽

Alissa Miklyaeva ◽

Margaretha A. Skowron ◽

Nina Overbeck ◽

Gereon Poschmann ◽

...

Keyword(s):

Germ Cell ◽

Dna Methyltransferase ◽

Synthetic Lethality ◽

Germ Cell Tumors ◽

Epigenetic Landscape ◽

Loss Of Function ◽

Pharmacological Inhibition ◽

Promising Target ◽

Cure Rates ◽

Tumor Types

Germ cell tumors (GCTs) are the most common solid malignancies found in young men. Although they generally have high cure rates, metastases, resistance to cisplatin-based therapy, and late toxicities still represent a lethal threat, arguing for the need of new therapeutic options. In a previous study, we identified downregulation of the chromatin-remodeling SWI/SNF complex member ARID1A as a key event in the mode of action of the histone deacetylase inhibitor romidepsin. Additionally, the loss-of-function mutations re-sensitize different tumor types to various drugs, like EZH2-, PARP-, HDAC-, HSP90- or ATR-inhibitors. Thus, ARID1A presents as a promising target for synthetic lethality and combination therapy. In this study, we deciphered the molecular function of ARID1A and screened for the potential of two pharmacological ARID1A inhibitors as a new therapeutic strategy to treat GCTs. By CRISPR/Cas9, we generated ARID1A-deficient GCT cells and demonstrate by mass spectrometry that ARID1A is putatively involved in regulating transcription, DNA repair and the epigenetic landscape via DNA Polymerase POLE and the DNA methyltransferase 1-associated protein DMAP1. Additionally, ARID1A/ARID1A deficiency or pharmacological inhibition increased the efficacy of romidepsin and considerably sensitized GCT cells, including cisplatin-resistant subclones, towards ATR inhibition. Thus, targeting ARID1A in combination with romidepsin and ATR inhibitors presents as a new putative option to treat GCTs.

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Combination chemotherapy with cisplatin and etoposide for malignant intracranial germ-cell tumors

Journal of Neurosurgery ◽

10.3171/jns.1989.70.5.0676 ◽

1989 ◽

Vol 70 (5) ◽

pp. 676-681 ◽

Cited By ~ 71

Author(s):

Tatsuya Kobayashi ◽

Jun Yoshida ◽

Junzo Ishiyama ◽

Satoshi Noda ◽

Akira Kito ◽

...

Keyword(s):

Germ Cell ◽

Combination Chemotherapy ◽

Germ Cell Tumors ◽

Intracranial Germ Cell Tumor ◽

Content Type ◽

Total Response Rate ◽

Intracranial Germ Cell Tumors ◽

Dna Histograms

✓ Antitumor activity against intracranial malignant teratoma by combination chemotherapy with cisplatin and etoposide was evaluated in experimental and clinical studies. A human teratoma cell line (Tera 2) was exposed in vitro to cisplatin and/or etoposide, after which cell growth inhibition and alterations of deoxyribonucleic acid (DNA) histograms were observed. The results indicated that a synergistic cytotoxic effect was achieved by use of both agents in combination. Four cases of recurrent intracranial germ-cell tumor (three malignant teratomas and one germinoma) were treated with cisplatin and etoposide. With this combinationtherapy, regression of the tumor was observed in all four cases (three complete and one partial), for a total response rate of 100%. During a follow-up period of 9 to 22 months, no recurrence or progression has been noted in three of these cases.

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NI-11 Clinical significance of intracystic diffusion hyperintensity lesions remaining after treatment of intracranial germ cell tumor

Neuro-Oncology Advances ◽

10.1093/noajnl/vdaa143.059 ◽

2020 ◽

Vol 2 (Supplement_3) ◽

pp. ii14-ii14

Author(s):

Motoki Takano ◽

Takeshi Takayasu ◽

Ushio Yonezawa ◽

Akira Taguchi ◽

Kazuhiko Sugiyama ◽

...

Keyword(s):

Germ Cell ◽

Clinical Significance ◽

Cyst Wall ◽

High Intensity ◽

Mature Teratoma ◽

Germ Cell Tumors ◽

Residual Tumor ◽

Cystic Tumor ◽

Intracranial Germ Cell Tumor ◽

Intensity Lesion

Abstract Background and purpose: About 30% of intracranial germ cell tumors are mixed germ cell tumors and teratomas are often found as those components. Intense chemoradiotherapy is performed according to the malignancy of the histopathology, but high-intensity lesion inside the cystic tumor on diffusion weighted imaging (DWI) sometimes remains after completion of the chemoradiotherapy. In this study, we examined the clinical significance of the DWI high-intensity lesion remaining in the cyst. METHODS: Five patients after initial chemoradiotherapy were resected residual tumor by craniotomy at our hospital from 2009 to 2019. Preoperative gadolinium-enhanced MRI defined the non-contrast-enhanced part of the tumor as intracystic, and DWI intensity was classified by its look as low-intensity, equal-intensity, and high-intensity compared to the cortex of the same slice. DWI signals in the solid area, cyst wall, and cyst were evaluated. Results: All cases were mature teratoma in histopathology, and no other tumor components were observed. On DWI, the cyst wall and solid part were visualized with low signal. High-intensity lesions and equal-intensity lesions in the cyst cavity were found in 3 and 1 cases, respectively. In these cases, pathological findings revealed a keratin-like substance in the cyst. Discussion: The intracystic high and equal intensity lesions on DWI removed after completion of chemoradiotherapy are considered to reflect the keratin-like component of mature teratoma. If DWI- high intensity and equal intensity lesions remain in the cyst of the tumor after the completion of chemoradiotherapy, tumor shrinkage cannot be expected even if the chemotherapy is strengthened. In such cases, we should consider to removing them by surgery. Conclusion: When DWI high and equal intensity lesions are found in the cysts of tumors remaining after chemoradiotherapy for intracranial germ tumors, it is possible that mature teratoma remains.

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A pragmatic diagnostic approach to primary intracranial germ cell tumors and their treatment outcomes

CNS Oncology ◽

10.2217/cns-2021-0012 ◽

2021 ◽

Vol 10 (4) ◽

Author(s):

Jeyaanth Venkatasai ◽

Rajesh Balakrishnan ◽

Balakrishnan Rajkrishna ◽

Patricia Sebastain ◽

Rikki Rorima John ◽

...

Keyword(s):

Overall Survival ◽

Germ Cell ◽

Germ Cell Tumors ◽

Progression Free Survival ◽

Cell Tumor ◽

Distinct Entity ◽

Intracranial Germ Cell Tumor ◽

Free Survival ◽

Intracranial Germ Cell Tumors ◽

Significant Difference

Background: Primary intracranial germ cell tumors (ICGCT) are often diagnosed with tumor markers and imaging, which may avoid the need for a biopsy. An intracranial germ cell tumor with mild elevation of markers is seldom stratified as a distinct entity. Methods: Fifty-nine patients were stratified into three groups: pure germinoma (PG), secreting germinoma (SG) and non-germinomatous germ cell tumors (NGGCTs). Results: At 5 years, progression-free survival and overall survival of the three groups (PG vs SG vs NGGCT) were 91% versus 81% versus 59%, and 100% versus 82% versus 68%, respectively. There was no statistically significant difference in outcome among histologically and clinically diagnosed germinomas. Conclusion: A criterion for clinical diagnosis when a biopsy is not feasible is elucidated, and comparable outcomes were demonstrated with histologically diagnosed germinomas.

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