Publications by authors named "Kaitlin Hoang"

4 Publications

  • Page 1 of 1

Genomic characterization of human brain metastases identifies drivers of metastatic lung adenocarcinoma.

Nat Genet 2020 04 23;52(4):371-377. Epub 2020 Mar 23.

Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA.

Brain metastases from lung adenocarcinoma (BM-LUAD) frequently cause patient mortality. To identify genomic alterations that promote brain metastases, we performed whole-exome sequencing of 73 BM-LUAD cases. Using case-control analyses, we discovered candidate drivers of brain metastasis by identifying genes with more frequent copy-number aberrations in BM-LUAD compared to 503 primary LUADs. We identified three regions with significantly higher amplification frequencies in BM-LUAD, including MYC (12 versus 6%), YAP1 (7 versus 0.8%) and MMP13 (10 versus 0.6%), and significantly more frequent deletions in CDKN2A/B (27 versus 13%). We confirmed that the amplification frequencies of MYC, YAP1 and MMP13 were elevated in an independent cohort of 105 patients with BM-LUAD. Functional assessment in patient-derived xenograft mouse models validated the notion that MYC, YAP1 or MMP13 overexpression increased the incidence of brain metastasis. These results demonstrate that somatic alterations contribute to brain metastases and that genomic sequencing of a sufficient number of metastatic tumors can reveal previously unknown metastatic drivers.
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http://dx.doi.org/10.1038/s41588-020-0592-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7136154PMC
April 2020

Genomic Analysis of Posterior Fossa Meningioma Demonstrates Frequent Mutations in Foramen Magnum Meningiomas.

J Neurol Surg B Skull Base 2019 Dec 10;80(6):562-567. Epub 2019 Jan 10.

Center for Cancer Research, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States.

 Posterior fossa meningiomas are surgically challenging tumors that are associated with high morbidity and mortality. We sought to investigate the anatomical distribution of clinically actionable mutations in posterior fossa meningioma to facilitate identifying patients amenable for systemic targeted therapy trials.  Targeted sequencing of clinically targetable , , and mutations was performed in 61 posterior fossa meningioma using Illumina NextSeq 500 to a target depth of >500 × . Samples were further interrogated for 53 cancer-relevant RNA fusions by the Archer FusionPlex panel to detect gene rearrangements.   1 ( ) mutations were detected in five cases (8.2%), four in the foramen magnum and one in the cerebellopontine angle. In contrast, none of the posterior fossa tumors harbored an ( ) or a ( ) mutation. Notably, the majority of foramen magnum meningiomas (4/7, 57%) harbored an mutation. In addition, common clinically targetable gene fusions were not detected in any of the cases.  A large subset of foramen magnum meningiomas harbor mutations and are therefore potentially amenable to targeted medical therapy. Genotyping of foramen magnum meningiomas may enable more therapeutic alternatives and guide their treatment decision process.
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http://dx.doi.org/10.1055/s-0038-1676821DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6864425PMC
December 2019

L265P mutation and loss are early mutational events in primary central nervous system diffuse large B-cell lymphomas.

Blood Adv 2019 02;3(3):375-383

Division of Hematology/Oncology, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA.

The genetic alterations that define primary central nervous system lymphoma (PCNSL) are incompletely elucidated, and the genomic evolution from diagnosis to relapse is poorly understood. We performed whole-exome sequencing (WES) on 36 PCNSL patients and targeted sequencing on a validation cohort of 27 PCNSL patients. We also performed WES and phylogenetic analysis of 3 matched newly diagnosed and relapsed tumor specimens and 1 synchronous intracranial and extracranial relapse. Immunohistochemistry (IHC) for programmed death-1 ligand (PD-L1) was performed on 43 patient specimens. Combined WES and targeted sequencing identified mutation in 67% (42 of 63) of patients, biallelic loss in 44% (16 of 36), and mutation in 61% (22 of 36). Copy-number analysis demonstrated frequent regions of copy loss (ie, ), with few areas of amplification. mutations were associated with improved progression-free and overall survival. We did not identify amplification at the / loci. IHC for PD-L1 revealed membranous expression in 30% (13 of 43) of specimens. Phylogenetic analysis of paired primary and relapsed specimens identified mutation and loss as early clonal events. PCNSL is characterized by frequent mutations within the B-cell receptor and NF-κB pathways. The lack of amplifications, along with membranous PD-L1 expression in 30% of our cohort, suggests that PD-1/PD-L1 inhibitors may be useful in a subset of PCNSL. WES of PCNSL provides insight into the genomic landscape and evolution of this rare lymphoma subtype and potentially informs more rational treatment decisions.
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http://dx.doi.org/10.1182/bloodadvances.2018027672DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6373750PMC
February 2019

Resolving the phylogenetic origin of glioblastoma via multifocal genomic analysis of pre-treatment and treatment-resistant autopsy specimens.

NPJ Precis Oncol 2017 18;1(1):33. Epub 2017 Sep 18.

1Division of Hematology/Oncology, Massachusetts General Hospital, Boston, Massachusetts USA.

Glioblastomas are malignant neoplasms composed of diverse cell populations. This intratumoral diversity has an underlying architecture, with a hierarchical relationship through clonal evolution from a common ancestor. Therapies are limited by emergence of resistant subclones from this phylogenetic reservoir. To characterize this clonal ancestral origin of recurrent tumors, we determined phylogenetic relationships using whole exome sequencing of pre-treatment IDH1/2 wild-type glioblastoma specimens, matched to post-treatment autopsy samples ( = 9) and metastatic extracranial post-treatment autopsy samples ( = 3). We identified "truncal" genetic events common to the evolutionary ancestry of the initial specimen and later recurrences, thereby inferring the identity of the precursor cell population. Mutations were identified in a subset of cases in known glioblastoma genes such as ( = 3), ( = 4) and ( = 5). However, by phylogenetic analysis, there were no protein-coding mutations as recurrent truncal events across the majority of cases. In contrast, whole copy-loss of chromosome 10 (12 of 12 cases), copy-loss of chromosome 9p21 (11 of 12 cases) and copy-gain in chromosome 7 (10 of 12 cases) were identified as shared events in the majority of cases. Strikingly, mutations in the promoter were also identified as shared events in all evaluated pairs (9 of 9). Thus, we define four truncal non-coding genomic alterations that represent early genomic events in gliomagenesis, that identify the persistent cellular reservoir from which glioblastoma recurrences emerge. Therapies to target these key early genomic events are needed. These findings offer an evolutionary explanation for why precision therapies that target protein-coding mutations lack efficacy in GBM.
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http://dx.doi.org/10.1038/s41698-017-0035-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5871833PMC
September 2017