An open protocol for modeling T Cell Clonotype repertoires using TCRβ CDR3 sequences

T cell receptor repertoires can be profiled using next generation sequencing (NGS) to measure and monitor adaptive dynamical changes in response to disease and other perturbations. Genomic DNA-based bulk sequencing is cost-effective but necessitates multiplex target amplification using multiple primer pairs with highly variable amplification efficiencies. Here, we utilize an equimolar primer mixture and propose a single statistical normalization step that efficiently corrects for amplification bias post sequencing. Using samples analyzed by both our open protocol and a commercial solution, we show high concordance between bulk clonality metrics. This approach is an inexpensive and open-source alternative to commercial solutions.

An open protocol for modeling T Cell Clonotype repertoires using TCRβ CDR3 sequences

T cell receptor repertoires can be profiled using next generation sequencing (NGS) to measure and monitor adaptive dynamical changes in response to disease and other perturbations. Genomic DNA-based bulk sequencing is cost-effective but necessitates multiplex target amplification using multiple primer pairs with highly variable amplification efficiencies. Here, we utilize an equimolar primer mixture and propose a single statistical normalization step that efficiently corrects for amplification bias post sequencing. Using samples analyzed by both our open protocol and a commercial solution, we show high concordance between bulk clonality metrics. This approach is an inexpensive and open-source alternative to commercial solutions.

An omic and multidimensional spatial atlas from serial biopsies of an evolving metastatic breast cancer

Mechanisms of therapeutic resistance and vulnerability evolve in metastatic cancers as tumor cells and extrinsic microenvironmental influences change during treatment. To support the development of methods for identifying these mechanisms in individual people, here we present an omic and multidimensional spatial (OMS) atlas generated from four serial biopsies of an individual with metastatic breast cancer during 3.5 years of therapy. This resource links detailed, longitudinal clinical metadata that includes treatment times and doses, anatomic imaging, and blood-based response measurements to clinical and exploratory analyses, which includes comprehensive DNA, RNA, and protein profiles; images of multiplexed immunostaining; and 2- and 3-dimensional scanning electron micrographs. These data report aspects of heterogeneity and evolution of the cancer genome, signaling pathways, immune microenvironment, cellular composition and organization, and ultrastructure. We present illustrative examples of how integrative analyses of these data reveal potential mechanisms of response and resistance and suggest novel therapeutic vulnerabilities.

Abstract LB010: SMMART Program: A multi-omics tumor board with a focus on breast cancer

Many of the current approaches to personalized medicine rely on sequencing DNA to identify actionable mutations. However, growing evidence suggests that a multi-omic approach to more broadly assess biology is needed to improve patient outcomes. We have implemented a workflow for tissue acquisition, multi-omic clinical testing, and correlated computational biology analysis, within the Serial Measurements of Molecular and Architectural Responses to Therapy (SMMART) Program (Mitri et al, J Transl Med 2018). We report biopsy metrics, CLIA analytics utilized, the operation of a multi-omics tumor board, and clinical outcomes in metastatic breast cancer patients. A detailed clinical history of each patient was obtained, including demographics, tumor type, treatment and response to prior therapies, imaging, and blood tumor biomarkers. A comprehensive set of clinical assays was performed on newly obtained tumor biopsies, including immunohistochemistry (ER, PR, HER2, AR, BCL-2, and PD-L1), a targeted next-generation sequencing panel covering 225 genes (GeneTrails® Comprehensive Solid Tumor Panel), whole exome sequencing (Tempus xE), whole transcriptomic sequencing (Illumina TruSeq RNA exome), and a multiplex protein analysis of 22 key cancer proteins and phosphoproteins on the Nanostring platform (NanoString Vantage 3D™ Solid Tumor Panel). The integrated clinical and analytical information was made available to the multidisciplinary SMMART Clinical Tumor Board that provided treatment recommendations; the final treatment plan was at the discretion of the treating physician. Between 1/1/2017-1/1/2020, 53 breast cancer patients were consented. Seven screen-failed due to a lack of sites amenable to biopsy and 8 were actively co-consented to other clinical trials. The remaining 38 patients are included in this preliminary report. A total of 63 biopsies were collected from lymph node, liver, bone, soft tissue, lung, skin, breast, and brain. Serial biopsies (≥2) were obtained for 15 patients. Analytics were generated in 93.7% of biopsies. Tumor boards were held for 15 patients (17 total sessions). The experience and information gathered thus far have yielded the following unique cases: (1) single patient analysis of omics, imaging, and response over 42 months, (2) identification of an ERBB3 mutation with downstream pathway activation that responded to HER2-targeted therapy, and (3) clinically significant variation in hormonal and HER2 receptor status over time. We will provide an analysis across the 38 patients of treatment outcomes, analytics information content, biological changes observed through serial biopsies, and tumor board interventions. We demonstrate the feasibility of implementing a deep, real-time analytics platform for metastatic breast cancer patients that can provide new insight into therapeutic opportunities. The observed clinical responses support further use and investigation of this approach.

Citation Format: Ben L. Kong, Brett E. Johnson, Jamie M. Keck, Souraya Mitri, Patrick Leyshock, Jayne M. Stommel, Kiara Siex, Marlana Klinger, Christina L. Zheng, Rochelle Williams-Belizaire, Shannon McWeeney, Jeremy Goecks, Annette Kolodzie, Alexander R. Guimaraes, George V. Thomas, Christopher L. Corless, Zahi I. Mitri, Joe W. Gray, Gordon B. Mills, Raymond C. Bergan. SMMART Program: A multi-omics tumor board with a focus on breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB010.

Abstract 4929: Leveraging multi-omics tumor boards for precision medicine in the OHSU SMMART Treatments Program

Comprehensive characterization of an individual’s cancer using multi-omic analyses and an expanding list of targeted therapies is providing an opportunity to uncover therapeutic vulnerabilities and rationally target multiple driving alterations in the tumor. To leverage this opportunity, a multi-disciplinary team is required to unravel the complexity of tumor behavior and genomic variant information, integrate data from multi-omic assays, and exploit potential synergies from combination therapy while avoiding toxicity, all of which occurs within the context of the patient’s clinical history and comorbidities. We report the preliminary experience of OHSU Knight Cancer Institute’s SMMART (Serial Measurements of Molecular and Architectural Responses to Therapy) Treatments Program Multi-omics Tumor Board (MTB). The role of the SMMART MTB, to date, has been to develop and optimize procedures in a feasibility protocol for future application in the clinical setting where we will provide personalized combinatorial treatment suggestions. Here we report our preliminary experience over the last 15 months with multi-disciplinary tumor boards for metastatic breast cancer. A deep analysis of data, in many cases from serial biopsies, enabled identification of personalized, multi-targeted therapy. Clinical and laboratory data are explored individually and collectively by oncologists, oncology pharmacists, molecular pathologists, cancer biologists, and computational biologists. Data from CLIA-certified analytics include, but are not limited to, a 124 gene targeted panel, whole exome sequencing, MSI, gene-fusion, RNAseq, and clinical IHC assays that provide status information about receptors (ER/PR/AR/HER2), proliferation rate, and tumor immunogenicity along with reflexive assays for expression of relevant proteins such as p16, RB, and PTEN. A customized LabKey® system allows for visual display of a patient’s clinical timeline with information about diagnoses, treatments, biopsies events, radiographic changes, and blood biomarkers; thereby providing MTB participants with a holistic view of the patient’s case summary. Our experience with several example breast cancer case scenarios identified therapeutic vulnerabilities that would not have been considered by a standard clinical tumor board with genomic data alone. Recent cases have included observations such as HER2 status switching, a rare pathogenic germline mutation, high PD-L1 expression, and gained expression of the androgen receptor. These cases further emphasize the value and importance of MTB discussions to oncologists for interpreting and analyzing complex multi-omic data and uncovering therapeutic options for patients. This experience will be utilized in the future for employing SMMART MTBs in a clinical setting as a platform to triage patients into different multi-targeted combinatorial treatment options.

Citation Format: Jamie M. Keck, Swapnil Parmar, Ben Kong, Zahi Mitri, Christopher Corless, Annette Kolodzie, Allison Creason, Jeremy Goecks, Patrick Leyshock, Kiara Siex, Brett E. Johnson, Janice Patterson, Laura Heiser, Anastasiya Olson, Matt Viehdorfer, Georgia Mayfield, Jennifer Laverdure, Joe W. Gray, Gordon B. Mills, Raymond C. Bergan. Leveraging multi-omics tumor boards for precision medicine in the OHSU SMMART Treatments Program [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4929.

Complement C5a Fosters Squamous Carcinogenesis and Limits T Cell Response to Chemotherapy

Complement is a critical component of humoral immunity implicated in cancer development; however, its biological contributions to tumorigenesis remain poorly understood. Using the K14-HPV16 transgenic mouse model of squamous carcinogenesis, we report that urokinase (uPA)⁺ macrophages regulate C3-independent release of C5a during premalignant progression, which in turn regulates protumorigenic properties of C5aR1⁺ mast cells and macrophages, including suppression of CD8⁺ T cell cytotoxicity. Therapeutic inhibition of C5aR1 via the peptide antagonist PMX-53 improved efficacy of paclitaxel chemotherapy associated with increased presence and cytotoxic properties of CXCR3⁺ effector memory CD8⁺ T cells in carcinomas, dependent on both macrophage transcriptional programming and IFNγ. Together, these data identify C5aR1-dependent signaling as an important immunomodulatory program in neoplastic tissue tractable for combinatorial cancer immunotherapy.

Quantitative Multiplex Immunohistochemistry Reveals Myeloid-Inflamed Tumor-Immune Complexity Associated with Poor Prognosis

Here, we describe a multiplexed immunohistochemical platform with computational image processing workflows, including image cytometry, enabling simultaneous evaluation of 12 biomarkers in one formalin-fixed paraffin-embedded tissue section. To validate this platform, we used tissue microarrays containing 38 archival head and neck squamous cell carcinomas and revealed differential immune profiles based on lymphoid and myeloid cell densities, correlating with human papilloma virus status and prognosis. Based on these results, we investigated 24 pancreatic ductal adenocarcinomas from patients who received neoadjuvant GVAX vaccination and revealed that response to therapy correlated with degree of mono-myelocytic cell density and percentages of CD8⁺ T cells expressing T cell exhaustion markers. These data highlight the utility of in situ immune monitoring for patient stratification and provide digital image processing pipelines to the community for examining immune complexity in precious tissue sections, where phenotype and tissue architecture are preserved to improve biomarker discovery and assessment.