GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 24, No. 1_Supplement ( 2018-01-01), p. B05-B05
    Abstract: Osteosarcoma (OS) patients who relapse after initial therapy or present with metastatic disease have an extremely poor prognosis. Chemotherapy regimens for these patients have limited efficacy and significant toxicities. In clinical practice, treatment is rarely informed by the specific genetic events in individual tumors. It is now well established that OS is characterized by numerous copy-number alterations (CNAs) and structural variations (SVs) in cancer-relevant genes. In contrast, recurrent point mutations are not seen. Thus, OS is a “C-class” (copy number driven) rather than an “M-class” (mutation driven) cancer. However, while a great deal of effort has been directed toward the identification of point mutations in druggable cancer genes, much less effort has gone into determining whether copy number alterations can be used to select therapies for aggressive cancers such as OS. The genomic heterogeneity of OS suggests that there may be different oncogenic drivers in subsets of patients. Thus, a systematic effort to identify targetable, patient-specific key driver genes (likely CNAs) is required. We established a clinically annotated patient-derived tumor xenograft (PDTX) bank of over 20 OS samples obtained at diagnosis, after surgical resection and from metastasis, thus representing the full spectrum of disease. Comparison between PDTXs and matched primary tumor demonstrated high correlation in copy number (by WGS) and gene expression (by RNAseq), suggesting that PDTXs are faithful preclinical models for OS. To identify recurrent CNAs, we analyzed this WGS dataset together with a public dataset of an additional 18 WGS samples. With this combined dataset of 42 samples, we searched for recurrent CNAs across a cancer gene list (1256 genes) generated by combining data from COSMIC and CIVIC. We identified 188 cancer genes amplified at least 4-fold in at least 2 samples. We then used a publicly available resource to identify genes considered “actionable” or “druggable” in cancer. The two most frequently amplified genes in OS are CCNE1 (16/42 cases) and MYC (13/42 cases). Other frequent alterations were those in the PI3K pathway (PTEN loss and/or AKT amplification), AURKB amplification and VEGFA amplification. Importantly, all of these CNAs were reflected in at least one PDTX models. We hypothesized that in OS some of these CNAs are key cancer drivers that can be targeted for cancer treatment. To test this hypothesis, we rank-ordered the CNAs in 9 PDTXs by the amplitude of the copy number gain. We used this simple heuristic to identify candidate drivers for individual samples. We then identified 6 drugs that could be used to target specific amplified genes and tested these drugs in corresponding CNA-matched PDTX. In 9/9 cases we saw significant growth inhibition. These results support the hypothesis that specific genes within CNA serve as oncogenic drivers in OS and thus outline a feasible approach to personalized, genome-informed therapy for this disease. Importantly, the drugs tested were not effective for PDTXs that did not carry the CNA. However, in all cases tested we saw only tumor stasis with a single agent. Therefore, combination therapies will be needed to induce adequate tumor cell kill in OS. Citation Format: Leanne Sayles, Marcus Breese, Amanda Koehne, Leung Stan, Marina Neyssa, Spunt Sheri, Lee Alex, Aviv Spillinger, Steve Dubois, Rafi Avedian, Doug Hawkins, Mohler David, Alejandro Sweet-Cordero. Preclinical evaluation of genome-informed therapy for osteosarcoma using patient-derived xenografts [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr B05.
    Type of Medium: Online Resource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2018
    detail.hit.zdb_id: 1225457-5
    detail.hit.zdb_id: 2036787-9
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 77, No. 13_Supplement ( 2017-07-01), p. 1948-1948
    Abstract: Osteosarcoma (OS) is a highly malignant cancer for which no targeted therapies are currently available. Current treatment modalities are limited to intensive, highly toxic chemotherapy and surgical resection. OS is characterized by wide spread copy number alterations and structural rearrangements. In contrast, no recurrent point mutations in protein-coding genes have been identified, suggesting that copy number alterations (CNAs) are key oncogenic drivers in this disease. However, as copy number alterations are highly heterogeneous, it is likely that each tumor has a distinct set of oncogenic drivers, making a unified treatment approach difficult to define. To identify candidate patient-specific drivers, we used a simple heuristic based on degree of amplification (as assessed by Whole Genome Sequencing) and changes in gene expression (as assessed by RNA sequencing). Using patient-derived tumor xenografts (PDTXs), we assessed if individual OS tumors respond to targeted therapy selected based on this approach. We rank-ordered CNAs in 9 PDTXs by the amplitude of the copy number gain and identified 5 pathways for targeted therapy including CCNE1, MYC, CDK4, PTEN/AKT and AURKB. Next, we prioritized drug choices to those that are in clinical trials and that are readily available and identified 5 drug matches for 9 PDTXs. We used the CDK2 inhibitor Dinaciclib for CCNE1 amplification and observed TGI of 85.5% and 67.8% for 2 different CCNE1 amplified PDTXs tested. CDK9 inhibitor AT7519 was used to treat 2 different MYC amplified PDTXs resulting in TGI of 104% and 83.9%. CDK4 amplified PDTXs were treated with CDK4/6 inhibitor, Palbociclib, resulting in TGI of 82.7%. AKT1 inhibitor MK-2206 was used to treat either AKT1 gains or PTEN loss resulting in TGI of 65.6% and 60.8% respectively. AURKB inhibitor AZD-1152 for AURKB amplified PDTXs in combination with cisplatin resulting in TGI 85.8%. These results support the hypothesis that specific genes within CNA regions serve as oncogenic drivers and that these represent therapeutic opportunities in OS. Our studies provide a roadmap for personalized genome-informed therapy of osteosarcoma, a cancer in which no new therapies have been identified in over 30 years. Citation Format: Leanne C. Sayles, Marcus Breese, Amanda L. Koehne, Stanley Leung, Aviv Spillinger, Alex Lee, Avanthi Shah, Krystal Straessler, Sheri Spunt, Neyssa Marina, Damon Jacobson, Raffi S. Avedian, David G. Mohler, Steven DuBois, Douglas S. Hawkins, E. Alejandro Sweet-Cordero. Tumor-specific copy number alterations uncover therapeutic opportunities in osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1948. doi:10.1158/1538-7445.AM2017-1948
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2017
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 78, No. 19_Supplement ( 2018-10-01), p. B49-B49
    Abstract: A promising tool for noninvasive disease monitoring is analysis of circulating tumor DNA (ctDNA). Healthy individuals carry 1-10 ng/ml of cell-free DNA (cfDNA) in the blood; in oncology patients, ctDNA, which is released from tumor cells, comprises a fraction of the cfDNA and carries tumor-specific alterations, such as mutations, translocations, and copy number alterations. Most ctDNA assays lack robust translocation detection capabilities, since they are designed for adult cancers, which are commonly characterized by mutations and copy number alterations. Even assays that are designed specifically for translocation detection have inherent limitations. They are often PCR-based with laborious methods. First, the patient’s primary tumor sample is sequenced to determine the unique sequence across the translocation breakpoint. This is followed by design of patient-specific primers that can only be used for that individual patient. We sought to design an off-the-shelf, broadly applicable ctDNA assay for translocation detection across pediatric Ewing sarcoma (ES), osteosarcoma (OS), rhabdomyosarcoma (RMS), and synovial sarcoma (SS). Recent work by our collaborators at Stanford University led to the development of CAncer Personalized Profiling by deep Sequencing (CAPP-Seq), a method capable of ultraspecific and ultrasensitive detection of ctDNA. Utilizing COSMIC and TCGA data, recent sequencing publications defining the landscape of pediatric sarcomas, and our own in-house sequencing data, we designed a pediatric sarcoma CAPP-Seq selector. This selector is comprised of biotinylated oligonucleotides that tile across the introns where translocation breakpoints occur in these pediatric sarcomas. The selector is applied to a sequencing library prepared from patient cfDNA to enrich for the genomic regions of interest via hybrid capture. The resulting enriched library undergoes next-generation sequencing to allow for detection and quantification of circulating tumor DNA. We have isolated cfDNA from pediatric sarcoma patients and found that their cfDNA levels are higher than levels found in adult oncology patients and healthy individuals, likely due to a large fraction of contributing ctDNA. We have applied our selector to pretreatment plasma samples from 5 EWS patients, 2 OS patients, 4 RMS patients, and 1 SS patient. We detected translocations in 10/12 of these samples. Tumor was available for 7/12 of these patients, and we were able to confirm our plasma results by whole-genome sequencing of the tumor, as a validation of our findings. Additionally, we have applied our selector to serial plasma samples collected over the course of treatment and found that ctDNA levels correlate with clinical status. We have detected translocations at allelic frequencies & lt;0.01%, demonstrating that our method is ultrasensitive and could be used to detect minimal residual disease. Our work demonstrates that CAPP-Seq can serve as an ultrasensitive, broadly applicable tool for circulating tumor translocation detection and offers promise as a method for noninvasive diagnosis and disease monitoring. Citation Format: Avanthi Tayi Shah, Tej D. Azad, Jake J. Chabon, Marcus Breese, Bogdan Tanasa, Aviv Spillinger, Stanley G. Leung, Maximilian Diehn, Ash A. Alizadeh, E. Alejandro Sweet-Cordero. Quantitating circulating tumor DNA in translocation-positive sarcoma patients using CAPP-Seq [abstract]. In: Proceedings of the AACR Special Conference: Pediatric Cancer Research: From Basic Science to the Clinic; 2017 Dec 3-6; Atlanta, Georgia. Philadelphia (PA): AACR; Cancer Res 2018;78(19 Suppl):Abstract nr B49.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2018
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 78, No. 19_Supplement ( 2018-10-01), p. PR05-PR05
    Abstract: Osteosarcoma (OS) patients who relapse after initial therapy or present with metastatic disease have an extremely poor prognosis. Chemotherapy regimens for these patients have limited efficacy and significant toxicities. Thus, new therapeutic approaches are urgently needed. OS is characterized by numerous copy-number alterations (CNAs) and structural variations (SVs) in cancer-relevant genes. In contrast, recurrent point mutations are not seen. Thus, OS is a C-class (copy number-driven) rather than an M-class (mutation-driven) cancer. However, little is known with regards to whether copy-number alterations can be used to select therapies for aggressive cancers such as OS. The genomic heterogeneity of OS suggests that there may be different oncogenic drivers in subsets of patients. Thus, a systematic effort to identify targetable, patient-specific key driver genes (likely CNAs) is required. We established a clinically annotated patient-derived tumor xenograft (PDTX) bank of 16 OS samples obtained at diagnosis, after surgical resection, and from metastasis, thus representing the full spectrum of disease. Comparison between PDTXs with a corresponding matched primary tumor demonstrated high correlation in copy number (by WGS for 12 samples) and gene expression (by RNAseq for 13 samples), suggesting that PDTXs are faithful preclinical models for OS. To identify recurrent CNAs, we analyzed this WGS dataset together with a public dataset of OS WGS samples. With this combined dataset of 69 samples from 52 patients, we searched for recurrent CNAs across an actionable cancer gene list and identified genes amplified at least 4-fold in at least 2 samples. The two most frequently amplified genes in OS are CCNE1 and MYC. Other frequent alterations were those in the PI3K pathway (PTEN loss and/or AKT amplification), AURKB amplification, CDK4 amplification, and VEGFA amplification. Importantly, all of these CNAs were reflected in at least one PDTX model. We hypothesized that in OS some of these CNAs are key cancer drivers that can be targeted for cancer treatment. To test this hypothesis, we rank-ordered the CNAs in 9 PDTXs by the amplitude of the copy number gain. We used this simple heuristic to identify candidate drivers for individual samples. We then identified 6 drugs that could be used to target specific amplified genes and tested these drugs in corresponding CNA-matched PDTX. In all cases, we saw significant growth inhibition in matched PDTXs whereas the effect was minimal in PDTXs treated with unmatched therapies. These results support the hypothesis that specific genes within CNA serve as oncogenic drivers in OS and thus outline a feasible approach to personalized, genome-informed therapy for this disease. This work could serve as the necessary preclinical proof of principle for development of a targeted therapy basket trial for OS. In parallel to these studies and in order to further define the evolutionary trajectory of OS, we have carried out a comprehensive analysis of both spatial and temporal changes that occur in OS samples from the same patient. This has allowed us to begin defining the role of whole-genome duplication events and chromothripsis as well as loss of heterozygosity in the evolution of OS. We are directing our current efforts towards merging this evolutionary analysis with knowledge of possible targetable events to further identify key vulnerabilities that could be exploited for therapeutic benefit. Citation Format: Leanne Sayles, Marcus Breese, Amanda Koehne, Krystal Straessler, Stanley Leung, Aviv Spillinger, Doug Hawkins, Steven Dubois, Alex Lee, Bogdan Tanasa, Kim Miok, Avanthi Shah, Sheri Spunt, Neyssa Marina, Kim Hazard, Alejandro Sweet-Cordero. Genomic analysis of osteosarcoma reveals opportunities for targeted therapy [abstract]. In: Proceedings of the AACR Special Conference: Pediatric Cancer Research: From Basic Science to the Clinic; 2017 Dec 3-6; Atlanta, Georgia. Philadelphia (PA): AACR; Cancer Res 2018;78(19 Suppl):Abstract nr PR05.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2018
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 78, No. 13_Supplement ( 2018-07-01), p. 2075-2075
    Abstract: Several recent studies (including BASIC3, iCAT, INFORM, PEDS-MIONCOSEQ) have used whole exome sequencing (WES) and RNA-seq in order to identify targetable chromosomal alterations in a large variety of pediatric cancers. Few studies have attempted to evaluate whether a more comprehensive approach including WGS and RNA-seq could be used to identify novel events relevant to the pathogenesis of advanced pediatric cancer. We analyzed a total of 59 patients (37 solid tumors, 11 brain tumors, and 10 leukemia/lymphomas) to determine the feasibility of using whole-genome sequencing (WGS) technology in conjunction with RNA-seq in order to identify actionable/druggable alterations in the pediatric cancer genomes. WGS analysis has been performed on 75 samples, that were collected from 45 patients, either at diagnosis or at relapse. For WGS analysis of germline-tumor pairs, after performing the sequence alignment with BWA-MEM to gender-specific hg38 genomes, we have used and verified a set of computational methods: 1) MuTect2 for SNV calling, 2) cn.mops for CNV calling, 3) DELLY and LUMPY for SV calling. Here we present our findings on the sets of SNV, CNV, SV, and gene fusions that we have identified by WGSA and RNA-seq, respectively, with a particular emphasis on the druggable alterations, and on the tumor response in the murine PDX models of the pediatric cancers. Consistent with previous observations, the mutational burden across pediatric cancers was low. While common mutations were identified, there was a long-tail of mutations that occurred at a low frequency. As anticipated, samples obtained post-chemotherapy had a higher mutational burden than treatment naive samples. TP53 was the most commonly mutated gene, but we also identified SNVs in other genes commonly mutated in cancer, such as ASXL1, NOTCH2, and RB1. Other novel recurring variants were discovered, further analysis of which is ongoing. Our results indicate that integrated WGS and RNA-seq analysis is feasible in the clinical setting and can reliably identify variants reported on commercially available gene panel testing. However, this approach also resulted in additional clinically relevant findings and allows for novel discovery that will further advance our understanding of these rare and highly aggressive pediatric malignancies. Citation Format: Bogdan Tanasa, Alex Lee, Marcus Breese, Avanthi Shah, Stan Leung, Heng-Yi Liu, Aviv Spillinger, Kimberly Hazard, Arun Rangaswami, Sheri Spunt, Norm Lacayo, Tabitha Cooney, Eric Alejandro Sweet-Cordero. Whole genome sequence analysis informs precision medicine of pediatric cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2075.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2018
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...