Germinoma Cell Research Articles

Endoscopic resection of pineal region tumors using infratentorial supracerebellar approach

Objective To investigate the feasibility and efficacy of purely endoscopic resection of pineal region tumors using infratentorial supracerebellar approach. Methods A retrospective study of general clinical data and treatment effect was performed for 4 cases of pineal region tumors who underwent pure endoscopic resection using infratentorial supracerebellar approach in Neurosurgery Department at Zhongshan Hospital of Fudan University from August 2014 to December 2015. Results Gross total resection was achieved in all 4 cases. Except 1 case of transient diplopia, no surgical complications were observed. The pathological diagnoses included germinoma, anaplastic astrocytoma, pilocytic astrocytoma and mixed germ cell tumor. Postoperative radiotherapy was administered in 2 patients and chemotherapy plus radiotherapy was performed in 1 patient. During the follow-up period (0.5 to 2.0 years), all patients had a normal life without tumor recurrence. Conclusions Purely endoscopic resection of pineal region tumors using infratentorial supracerebellar approach seems feasible. It may be considered as an alternative approach for certain pineal region tumors. Key words: Neuroendoscopy; Pinealoma; Approach

HCP-02EXPERIENCE WITH MANAGEMENT OF GERM CELL TUMOURS IN TERTIARY CARE CENTRE IN EASTERN INDIA

AIM OF THE STUDY: To analyze paediatric patients who were diagnosed with intracranial germ cell tumours, to assess their presentation, management details and to understand their overall prognoses in terms of survival. MATERIAL AND METHODS: Of the 22 patients, there were 12 patients with germinoma, 4 patients with immature teratoma and 1 patient with mature teratoma, 1 with embryonal cell carcinoma, and 4 mixed germ cell tumours. The age of presentation ranged from 3 months to 15 years and there was a clear female preponderance. The most common presentation was with raised intracranial pressure and 11of our patients had papilledema at presentation, 1 presented with seizure, 1 with diabetes insipidus and 1 had precocious puberty at the time of presentation. With the exception of 4 infants who were admitted with poor levels of consciousness and who had presumptive diagnoses of teatimes, and where squash preparation provided definite diagnoses at the time of endoscopic third ventriculostomy, serum markers were obtained in all patients, while CSF tumour markers were obtained in only 14 patients (not done in 4 for technical reasons), Alpha-fetoprotein and beta HCG were measured in all cases. Placental alkaline phosphatase (PLAP) was again not available to us. In 12 patients endoscopic third ventriculostomy and biopsy procedures were done. Those with positive tumour markers (3 patients) no histological diagnoses were obtained and underwent direct radiotherapy. RESULTS: Median survival in the teratoma group was 11.6 months. The germinoma and mixed germ cell tumours had better outcome(stable and asymtomatic at 2 years). The child with embryonal carcinoma did not even survive till adjuvant therapy could be started. CONCLUSION: In our scenario we faced some special problems. 1) tumour markers in CSF could not be measured in 4 cases and we had to depend on serum markers in those cases. 2) almost all our patients with severely raised intracranial pressure required immediate CSF diversion procedures and so we could histological samples for squash examination. Limited resources and limited access to high end laboratory facilities provided a challenge for management of these patients.

Abstract 1193: Establishment of patient tumor-derived orthotopic xenograft models of metastatic pediatric germinoma

Abstract Despite comprising up to 10% of pediatric CNS tumors, an animal model of intracranial germinoma has not been previously established. Standard of case for germinoma is radiation therapy, with recent evidence that neo-adjuvant chemotherapy may allow reduction of radiation dose, but concern for neuro-cognitive toxicity remains despite the reduction of radiation. A clinically relevant animal model of germinoma would facilitate investigation and discovery of novel agents which may obviate the need for radiation in the future. To develop xenograft mouse models, we implanted germinoma tumor cells from two children with metastatic disease, one from a surgical specimen of a cervical metastatic tumor and the second from disseminated tumor cells in the CSF, directly into the right cerebral hemispheres of NOD-SCID mice. Both patient tumor samples have undergone whole exome sequencing; one of the two models has a germinoma-associated mutation in c-kit. The tumors have been serially passaged in xenografts for 3-5 times, with each passaged tumor maintaining the ability to generate tumors, suggestive of the persistence of viable tumorigenic/tumor stem cells. Data from additional tumor models established by our lab have confirmed molecular and genetic fidelity between xenograft-initiating human brain tumors and their corresponding murine models. The orthotopic location in the mouse brain of the xenograft model should also reasonably replicate the human germinoma tumor microenvironment. Cultured cells are currently growing from both tumor models in order to establish germinoma cell lines. In summary, our orthotopic xenograft murine models of two metastatic pediatric germinomas are the first to be established for this tumor type. These models will allow much needed pre-clinical drug testing of chemotherapeutics and combination therapies as well as further biologic characterization of pediatric germinomas. Citation Format: Holly B. Lindsay, Mari Kogiso, Lin Qi, Teo Wan Yee, Yulun Huang, Hua Mao, Frank Lin, Patricia Baxter, Jack M. Su, Keita Terashima, Laszlo Perlaky, Ching C. Lau, Donald W. Parsons, Murali Chintagumpala, Xiao-Nan Li. Establishment of patient tumor-derived orthotopic xenograft models of metastatic pediatric germinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1193. doi:10.1158/1538-7445.AM2014-1193

Abstract LB-355: Whole-exome sequencing of intracranial germ cell tumors reveals frequent mutations in KIT and RAS pathways and histone demethylases.

Abstract Intracranial germ cell tumors (IGCTs) are a group of rare pediatric brain tumors affecting mainly male adolescents and young adults. The incidence of IGCTs varies significantly according to geographic locations with the highest incidence in Japan and other East Asian countries. Taken together, these characteristics suggest predisposing germline factors. IGCTs can be divided into two main groups, pure germinoma and nongerminomatous germ cell tumor (NGGCT). The former in general responds well to chemoradiotherapy whereas the latter has a rather poor prognosis. Currently the only known gene associated with this disease is KIT, which is mutated in ~25% of IGCTs. Due to the scarcity of tissues available for research, the molecular biology of IGCTs remains largely unknown. Thus, deeper understanding of the pathogenesis of these unusual tumors should lead to new insights into the underlying cancer biology and the development of novel therapeutics for this rare and deadly disease. Using whole-exome sequencing and SNP array, we have analyzed 28 IGCT tumors (12 pure germinomas, 12 NGGCTs and 4 mixed GCTs) collected from Japan (21), Hong Kong (4) and United States (3). Somatic mutations of KIT were detected in 29% of cases, primarily in germinomas. In an additional 38% of the cases, deleterious somatic mutations were identified in important downstream mediators of KIT signal transduction including KRAS, NRAS, MTOR and their respective regulators, NF1 and PTEN. Mutations in KIT were mutually exclusive with mutations in RAS. Furthermore, 21% of patients showed inactivation of tumor suppressor genes (TSGs) including BCORL1, PTEN, NF1 and SMAD3. Inactivation of TSGs coexisted in tumors with activation of KIT/RAS oncogenes, suggesting these mutations act cooperatively in tumorigenesis. Copy-number analysis revealed almost exclusively arm-level gains and losses. Over 90% of the germinomas exhibited chromosomal imbalance and uniparental disomy of multiple chromosomes, suggesting aberrant meiotic division may possibly play a role in the pathogenesis of this disease. Patterns of chromosome imbalance within a given tumor revealed subclonal structure in 58% of the analyzed cases. Finally, we found in this cohort a significant enrichment (39%) of novel or rare germline variants in histone demethylases, compared with the control cohorts, suggesting epigenetic deregulation may be an important early event in tumorigenesis. One histone demethylase harbored a risk allele present at significantly higher frequency in our male cases compared to a Japanese control population, a finding that could explain both the population prevalence and sex differences in this disease. This study has important implications for our understanding of the pathogenesis of IGCTs, and suggests potential targets for the development of therapeutics focused on inhibitors of KIT/RAS activation. Citation Format: Linghua Wang, Shigeru Yamaguchi, Keita Terashima, Matthew D. Burstein, Jiayi M. Sun, Tomonari Suzuki, Ryo Nishikawa, Hideo Nakamura, Atsushi Natsume, Shunsuke Terasaka, Ho-Keung Ng, Robert C. Dauser, William E. Whitehead, Adesina M. Adekunle, Donna M. Muzny, Richard A. Gibbs, Ching C. Lau, David A. Wheeler. Whole-exome sequencing of intracranial germ cell tumors reveals frequent mutations in KIT and RAS pathways and histone demethylases. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-355. doi:10.1158/1538-7445.AM2013-LB-355

Abstract 2491: High-dose acetaminophen with N-acetylcysteine rescue enhances the efficacy of cisplatin chemotherapy

Abstract Acetaminophen (AAP) has been shown to enhance cisplatin (CDDP) cytotoxicity in hepatoblastoma cell lines. Further, one published case report demonstrated clinical efficacy of administering acetaminophen in conjunction with cisplatin and followed 6 hours later with n-acetylcysteine (NAC) rescue. In this study, atypical rhabdoid tumor (ATRT) and germinoma cells were treated with CDDP and AAP with or without NAC rescue. We then evaluated the cells with western blots for cleaved PARP and caspase 3 to demonstrate effects on apoptosis. Further, MTS assays were performed to evaluate cell viability of treated cells. To evaluate the effects of the various treatments on oxidative stress, dihydroethidium (DHE) and 2′,7′-dichlorofluorescin (DCFH) assays were performed to test for superoxide and hydrogen peroxide levels, respectively. It was demonstrated that AAP enhances CDDP cell kill and apoptosis in germinoma and ATRT cell lines. Further, both AAP and CDDP, independently and together, cause increased oxidative stress as measured by DHE and DCFE, but this oxidative stress is only reversed by NAC in the DCFE assay. This makes sense because NAC, a glutathione precursor, detoxifies peroxide but not superoxide. Further, our group has learned of five previously unpublished patients with recurrent liver tumors (hepatocellular carcinoma and hepatoblastoma) treated with AAP and CDDP with delayed NAC rescue. All patients tolerated the treatment well. Two of the five patients responded to the treatment, suggesting the potential of this approach. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2491. doi:1538-7445.AM2012-2491

Abstract 3155: High-throughput profiling of miRNA expression in plasma and cerebrospinal fluid using OpenArray® platform for biomarker discovery

Abstract OpenArray® platform can be used for expression profiling using TaqMan® assays that enables higher throughput, less assay consumption, and lower sample input than other low-density assay platforms. One OpenArray® plate has 3,072 through-holes, each of which requires only 33nl of reaction volume. We combined the workflow of Megaplex™ RT primer pools and pre-amplification with TaqMan® MicroRNA assays on OpenArray® plates. Each OpenArray® plate provides the capacity of 3 samples, and each run can take up to 3 plates with a run time about 2.5 hours. Therefore, each typical work day can have 4 instrument runs generating expression data of 754 miRNAs from 36 samples. This platform is ideal to identify potential miRNA biomarkers within a short period of time by screening a large cohort of clinical specimens that might have limitations in sample size, contamination of PCR inhibitors, or low abundance of target miRNAs. We optimized the original workflow of Megaplex™ RT primer pools and pre-amplification before applying to the OpenArray® plates to ensure increasing detection sensitivity while maintaining the linearity in plasma samples. In a proof-of-principle investigation, we applied the new protocol to a small panel of plasma and cerebrospinal fluid (CSF) specimens derived from pediatric patients diagnosed with either germinoma or non-germinoma germ cell tumors of the brain, and benchmarked with another miRNA expression profiling platform, TaqMan® Array Card (TAC), and OpenArray® plates demonstrated good concordance with the TAC. Expression patterns of miRNAs detected in our CSF samples are largely consistent with previously published miRNAs differentially expressed in primary cancerous tissues between these two types of intracranial germ cell tumors. (For Research Use Only. Not for use in diagnostic procedures.) Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3155. doi:1538-7445.AM2012-3155

Monoclonal antibody, Mab 12C3, is a sensitive immunohistochemical marker of early malignant change in epithelial ovarian tumors.

A murine monoclonal antibody (MAb 12C3) that is specific to human ovarian carcinomas was generated by immunizing mice with a human ovarian germinoma cell line (JOHYC-2). The antigen distribution that was defined by MAb 12C3 in normal and malignant human tissues was analyzed by immunohistochemistry on paraffin-embedded and frozen sections. The antibody reacted with 67.7% (21 of 31 cases) of epithelial ovarian carcinomas (6 of 12 cases of serous cystadenocarcinoma, 5 of 7 cases of mucinous cystadenocarcinoma, 7 of 9 cases of clear cell carcinoma, 3 of 3 cases of endometrioid adenocarcinoma), but did not react with any of the benign epithelial ovarian adenomas tested. Partial regions of borderline ovarian malignancies that exhibited marked papillary projection of the lining cells with cellular atypia reacted positively with MAb 12C3 in 14 of 25 cases (56.0%). The histologic features of regional early malignant change corresponded to the expression of the MAb 12C3 epitope in the borderline malignant tumor cells. There was a low frequency of reaction (4.3%) between the antibody and other gynecologic and nongynecologic malignancies (46 cases of 12 tissues). In normal tissues, the antibody reacted positively with only three tissues, including corpora lutein cells, excretory ducts in the submandibular gland, and basal cells of the sebaceous glands. The antigen epitope defined by MAb 12C3 was present on a glycoprotein with a molecular mass of 200 kDa and did not exhibit any cross-reactivity with other well-known tumor markers. These data suggest that MAb 12C3 may be a useful tool for the immunohistologic detection of early malignant changes in epithelial ovarian tumors. In addition, MAb 12C3 also may facilitate a differential diagnosis between benign and borderline malignancies.