Biology subjects

Lee, A. V.

Publications and source records attributed to Lee, A. V..

3 recordsLinked to original sources

bioRxiv2018

Targeted mutation detection in breast cancer using MammaSeqTM

BackgroundBreast cancer is the most common invasive cancer among women worldwide. Next-generation sequencing (NGS) has revolutionized the study of cancer across research labs around the globe, however genomic testing in clinical settings remain limited. Advances in sequencing reliability, pipeline analysis, accumulation of relevant data, and the reduction of costs are rapidly increasing the feasibility of NGS-based clinical decision making.\n\nMethodsWe report the development of MammaSeq, a breast cancer specific NGS panel, targeting 79 genes and 1369 mutations, optimized for use in primary and metastatic breast cancer. To validate the panel, 46 solid tumor and 14 plasma circulating-free cfDNA samples were sequenced to a mean depth of 2311X and 1820 X respectively. Variants were called using Ion Torrent Suite 4.0 and annotated with cravat CHASM. CNVKit was used to call copy number variants in the solid tumor cohort. The oncoKB Precision Oncology Database was used to identify clinically actionable variants. ddPCR was used to validate select cfDNA mutations.\n\nResultsIn cohorts of 46 solid tumors and 14 cfDNA samples from patients with advanced breast cancer we identified 592 and 43 protein coding mutations. Mutations per sample in the solid tumor cohort ranged from 1 to 128 (median 3) and the cfDNA cohort ranged from 0 to 26 (median 2.5). Copy number analysis in the solid tumor cohort identified 46 amplifications and 35 deletions. We identified 26 clinically actionable variants (levels 1-3) annotated by OncoKB, distributed across 20 out of 46 cases (40%), in the solid tumor cohort. Allele frequencies of ESR1 and FOXA1 mutations correlated with CA.27.29 levels in patient matched blood draws.\n\nConclusionsIn solid tumors biopsies and cfDNA, MammaSeq detects clinicaly actionable mutations (oncoKB levels 1-3) in 22/46 (48%) solid tumors and in 4/14 (29%) of cfDNA samples. MammaSeq is a targeted panel suitable for clinically actionable mutation detection in breast cancer.

cancer biology↗

bioRxiv2018

Loss of E-cadherin enhances IGF1-IGF1R pathway activation and sensitizes breast cancers to anti-IGF1R inhibitors

PurposeInsulin-like growth factor I (IGF1) signaling regulates breast cancer initiation and progression and associated cancer phenotypes. We previously identified E-cadherin (CDH1) as a repressor of IGF1 signaling and in this study examined how loss of E-cadherin affects IGF1R signaling and response to anti-IGF1R therapies in breast cancer.\n\nExperimental DesignBreast cancer cell lines were used to assess how altered E-cadherin levels regulate IGF1R signaling and response to two anti-IGF1R therapies. In situ proximity ligation assay (PLA) was used to define interaction between IGF1R and E-cadherin. TCGA RNA-seq and RPPA data was used to compare IGF1R activation in estrogen receptor positive (ER+) invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) tumors. ER+ ILC cell lines and xenograft tumor explant cultures were used to evaluate efficacy to IGF1R pathway inhibition in combination with endocrine therapy.\n\nResultsDiminished functional E-cadherin increased both activation of IGF1R signaling and efficacy to anti-IGF1R therapies. PLA demonstrated a direct endogenous interaction between IGF1R and E-cadherin at points of cell-cell contact. Increased expression of IGF1 ligand and levels of IGF1R phosphorylation were observed in E-cadherin deficient ER+ ILC compared to IDC tumors. IGF1R pathway inhibitors were effective in inhibiting growth in ER+ ILC cell lines and synergized with endocrine therapy and similarly IGF1R inhibition reduced proliferation in ILC tumor explant culture.\n\nConclusionsWe provide evidence that loss of E-cadherin hyperactivates the IGF1R pathway and increases sensitivity to IGF1R targeted therapy, thus identifying the IGF1R pathway as a potential novel target in E-cadherin deficient breast cancers.\n\nSTATEMENT OF SIGNIFICANCEIGF1R signaling is an attractive therapeutic target in breast cancer due to its regulation of proliferation, migration, and invasion. However, clinical trials targeting IGF1R have largely been unsuccessful due to lack of biomarkers to stratify patients for therapeutic response. In this study, we demonstrate loss of E-cadherin as a potential biomarker for response to anti-IGF1R therapy, and show efficacy of IGF1R inhibition in ER+ ILC in combination with endocrine therapy. Patients with ER+ ILC have poorer long-term outcomes than patients with ER+ IDC and have a propensity for increased late recurrences, highlighting the need for improved therapeutic strategies for this subtype of breast cancer. Here, we credential IGF1R inhibition as a novel therapeutic strategy in combination with endocrine therapy for the treatment of ER+ ILC.

cancer biology↗

bioRxiv2017

Exome-Capture RNA-Sequencing Of Decade-Old Breast Cancers And Matched Decalcified Bone Metastases Identifies Clinically Actionable Targets

Bone metastases (BoM) are a significant cause of morbidity in patients with Estrogen-receptor (ER)-positive breast cancer, yet characterizations of human specimens are limited. In this study, exome-capture RNA-sequencing (ecRNA-seq) on aged (8-12 years), formalin-fixed paraffin-embedded (FFPE) and decalcified cancer specimens was first evaluated. Gene expression values and RNA-seq quality metrics from FFPE or decalcified tumor RNA showed minimal differences when compared to matched flash-frozen or non-decalcified tumors. ecRNA-seq was then applied on a longitudinal collection of 11 primary breast cancers and patient-matched de novo or recurrent BoM. BoMs harbored shifts to more Her2 and LumB PAM50 intrinsic subtypes, temporally influenced expression evolution, recurrently dysregulated prognostic gene sets and altered expression of clinically actionable genes, particularly in the CDK-Rb-E2F and FGFR-signaling pathways. Taken together, this study demonstrates the use of ecRNA-seq on decade-old and decalcified specimens and defines expression-based tumor evolution in long-term, estrogen-deprived metastases that may have immediate clinical implications.\n\nGrant SupportResearch funding for this project was provided in part by a Susan G. Komen Scholar award to AVL and to SO, the Breast Cancer Research Foundation (AVL and SO), the Fashion Footwear Association of New York, the Magee-Womens Research Institute and Foundation, and through a Postdoctoral Fellowship awarded to RJW from the Department of Defense (BC123242). NP was supported by a training grant from the NIH/NIGMS (2T32GM008424-21) and an individual fellowship from the NIH/NCI (5F30CA203095).\n\nConflicts of Interest DisclosureNo relevant conflicts of interest disclosed for this study.\n\nAuthor ContributionsStudy concept and design (NP, RJW, SO, AVL); acquisition, analysis, or interpretation of data (all authors); drafting of the manuscript (NP, RJW, SO, AVL); critical revision of the manuscript for important intellectual content (all authors); administrative, technical, or material support (PCL, AB, RB, KRW, WH, JK, MR, ZF, AMB).

cancer biology↗