Sean Richard Dinn

Highly multiplexed single-cell analysis of formalin-fixed, paraffin-embedded cancer tissue

Limitations on the number of unique protein and DNA molecules that can be characterized microscopically in a single tissue specimen impede advances in understanding the biological basis of health and disease. Here we present a multiplexed fluorescence microscopy method (MxIF) for quantitative, single-cell, and subcellular characterization of multiple analytes in formalin-fixed paraffin-embedded tissue. Chemical inactivation of fluorescent dyes after each image acquisition round allows reuse of common dyes in iterative staining and imaging cycles. The mild inactivation chemistry is compatible with total and phosphoprotein detection, as well as DNA FISH. Accurate computational registration of sequential images is achieved by aligning nuclear counterstain-derived fiducial points. Individual cells, plasma membrane, cytoplasm, nucleus, tumor, and stromal regions are segmented to achieve cellular and subcellular quantification of multiplexed targets. In a comparison of pathologist scoring of diaminobenzidine staining of serial sections and automated MxIF scoring of a single section, human epidermal growth factor receptor 2, estrogen receptor, p53, and androgen receptor staining by diaminobenzidine and MxIF methods yielded similar results. Single-cell staining patterns of 61 protein antigens by MxIF in 747 colorectal cancer subjects reveals extensive tumor heterogeneity, and cluster analysis of divergent signaling through ERK1/2, S6 kinase 1, and 4E binding protein 1 provides insights into the spatial organization of mechanistic target of rapamycin and MAPK signal transduction. Our results suggest MxIF should be broadly applicable to problems in the fields of basic biological research, drug discovery and development, and clinical diagnostics.

Quantitative single cell analysis of cell population dynamics during submandibular salivary gland development and differentiation

Summary Epithelial organ morphogenesis involves reciprocal interactions between epithelial and mesenchymal cell types to balance progenitor cell retention and expansion with cell differentiation for evolution of tissue architecture. Underlying submandibular salivary gland branching morphogenesis is the regulated proliferation and differentiation of perhaps several progenitor cell populations, which have not been characterized throughout development, and yet are critical for understanding organ development, regeneration, and disease. Here we applied a serial multiplexed fluorescent immunohistochemistry technology to map the progressive refinement of the epithelial and mesenchymal cell populations throughout development from embryonic day 14 through postnatal day 20. Using computational single cell analysis methods, we simultaneously mapped the evolving temporal and spatial location of epithelial cells expressing subsets of differentiation and progenitor markers throughout salivary gland development. We mapped epithelial cell differentiation markers, including aquaporin 5, PSP, SABPA, and mucin 10 (acinar cells); cytokeratin 7 (ductal cells); and smooth muscle &agr;-actin (myoepithelial cells) and epithelial progenitor cell markers, cytokeratin 5 and c-kit. We used pairwise correlation and visual mapping of the cells in multiplexed images to quantify the number of single- and double-positive cells expressing these differentiation and progenitor markers at each developmental stage. We identified smooth muscle &agr;-actin as a putative early myoepithelial progenitor marker that is expressed in cytokeratin 5-negative cells. Additionally, our results reveal dynamic expansion and redistributions of c-kit- and K5-positive progenitor cell populations throughout development and in postnatal glands. The data suggest that there are temporally and spatially discreet progenitor populations that contribute to salivary gland development and homeostasis.

Asymmetric synthesis of tetrabenazine and dihydrotetrabenazine.

The enantioselective synthesis of (+)-tetrabenazine (TBZ) and (+)-dihydrotetrabenazine (DTBZ), agents of significant interest for therapeutic and molecular imaging applications, has been completed in 21% (TBZ) and 16% (DTBZ) overall yield and in >97% ee from the starting dihydroisoquinoline. The synthesis utilizes Sodeokas palladium-catalyzed asymmetric malonate addition to set the initial stereocenter followed by a number of diastereoselective transformations to incorporate the remaining asymmetric centers.

Multiplexed Analysis of Proteins in Tissue Using Multispectral Fluorescence Imaging

We present a new application of multispectral analysis for subcellular measurement of multiple proteins in formalin-fixed paraffin embedded tissue and cells. Typically, the targets of interest are present in the same or spatially overlapping cellular compartments. Such co-localization can complicate analysis and interpretation of the images obtained using traditional fluorescence, especially when spectrally overlapping labels are present. The spectral properties of currently available fluorescent dyes set an upper limit to the number of molecules that can be detected simultaneously with traditional fluorescence. By exciting a set of fluorophores at the same wavelength and unmixing their emission signals from background autofluorescence, we were able to image three targets in a single channel. This parallel imaging approach provides significant advantages for multiplexed analysis of tissues and cells.

A novel, automated technology for multiplex biomarker imaging and application to breast cancer

Multiplexed immunofluorescence is a powerful tool for validating multigene assays and understanding the complex interplay of proteins implicated in breast cancer within a morphological context. We describe a novel technology for imaging an extended panel of biomarkers on a single, formalin‐fixed paraffin‐embedded breast sample and evaluating biomarker interaction at a single‐cell level, and demonstrate proof‐of‐concept on a small set of breast tumours, including those which co‐express hormone receptors with Her2/neu and Ki‐67.

Inferring Mechanism of Action of an Unknown Compound from Time Series Omics Data

Identifying the mechanism of action (MoA) of an unknown, possibly novel, substance (chemical, protein, or pathogen) is a significant challenge. Biologists typically spend years working out the MoA for known compounds. MoA determination is especially challenging if there is no prior knowledge and if there is an urgent need to understand the mechanism for rapid treatment and/or prevention of global health emergencies. In this paper, we describe a data analysis approach using Gaussian processes and machine learning techniques to infer components of the MoA of an unknown agent from time series transcriptomics, proteomics, and metabolomics data.

Abstract P2-04-06: Demonstration of immune cell and pathway heterogeneity in Singapore DCIS samples using novel hyperplexing method (MultiOmyx®)

Breast cancer is the most common malignancy in Singapore women with rising incidence across all ethnic groups (Chinese, Malays and Indians). Ductal carcinoma in situ (DCIS) is the earliest non-invasive stage of disease and has been shown to account for approximately 26% of diagnoses in all women participating in the Breast-Screen Singapore program. Despite availability of breast screening, there are still Singapore women presenting with locally advanced breast cancer. The goal of the current study was to investigate pathway and immune cell heterogeneity in low, intermediate and high nuclear grade DCIS using a newly developed method for in situ hyperplexed analysis of multiple proteins in a single FFPE tissue (MultiOmyx). FFPE samples from patients (n= 15) diagnosed with DCIS were provided by Singapore General Hospital. Patients were of Chinese origin, ranged from 50-59 years, were all post-menopausal, and included low (n=5), intermediate (n=5) and high grade (n=5) samples. All histological diagnoses were reviewed by a single pathologist. Following a single antigen retrieval step, DAPI and cytokeratin staining was conducted and imaged at 10X. Based on DAPI, cytokeratin and autofluorescence, an HE San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-04-06.

Abstract P4-05-12: MultiOmyx™ screening for prognostic indicators of breast cancer

Over the last three decades, the incidence of early-stage breast cancer has doubled while the incidence of late stage breast cancer has slightly decreased; however, the standard treatment for both has not changed significantly in the last 10 years. Of those diagnosed with early-stage breast cancer, 30% will develop recurrent disease, though there is currently no diagnostic available to identify these cases. Conversely, identifying late stage patients with a low- risk for recurrence could spare them from post-surgical chemotherapy. We have developed a technology that allows in situ staining and analysis of up to 60 proteins on a single tissue slide. In this exploratory study we evaluated 25 known biomarkers on a cohort of more than 800 breast cancer cases assembled onto three tissue arrays. The cohort spans clinical grades and breast cancer subtypes, and is thus useful in novel associations of biomarker expression across a variety of clinical features. Twenty-five markers were chosen based on literature reports for marker association with disease recurrence and represent a range of biological features including signaling pathways and cell phenotypes. The slides were sequentially stained with antibodies that were directly conjugated to Cy3 and Cy5 dyes, imaged, evaluated for quality and subject inclusion, and subsequently analyzed for statistical correlations of expression values to clinical features. The images were then processed using a single cell analysis algorithm which allows for quantification of individual tumor cells and signal intensities for the markers to be extracted from sub-cellular domains (nucleus, cytoplasm, and membrane of each cell) allowing unique patterns of protein expression to be determined. Univariate Cox proportional hazards analysis was first applied to determine those features with strongest association with ‘death due to disease’. Of the 25 markers analyzed, several markers (e.g. API3, AMPH2, beta-catenin, CD44, CEACAM5, CK15, CK19, cMET, Her2, Ki67, TRIM29) were found to have strong association with poor outcome (FDR TM methodology enabled us to verify a subset of biomarkers that are clinically relevant to breast cancer outcome. Using this technology could lead to identification of novel biosignatures that stratify patients and enable precision medicine that results in better treatment decisions and prognosis for patients. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-05-12.

Abstract A28: Multiplexed immunofluorescence in formalin-fixed paraffin-embedded prostate cancer

Traditional immunohistochemistry serves as a vital diagnostic assay as it allows for semiquantitatively probing the magnitude and spatial distribution of protein expression and posttranslational modifications. Unfortunately, an accurate portrayal of disease often requires several immunohistochemical stains, which are run on separate tissue sections. The application of transcriptomics analyses in cancer classification has led to the generation of multivariate index analyses that confer diagnostic, prognostic, and predictive signatures of disease. However this method is limited by the inability consider target expression in the context of tissue (stroma, epithelium) or cell (e.g. stem/progenitor cells) type. A unifying platform that would allow for the quantitative spatial analysis of multiplexed in situ target measurements promises to exploit the best features of both systems. To this end, we have developed a novel multiplexed fluorescence immunohistochemistry assay that is capable of quantitative analysis of >25 antigens in a single formalin-fixed paraffin-embedded tissue section, as well as image and data analysis capabilities for analyzing the multidimensional data. By inclusion of targets for cell and tissue compartments, including nuclei, cytoplasm and membrane, we have demonstrated the ability to investigate subcellular protein expression, phosphorylation and co-localization in individual cells. In the present study we have stained a cohort of 79 prostate cancer patients of varying Gleason grades for a total of 24 antigens, representing key mediators of cell signaling, tumor suppressors and oncogenes, tumor associated phenotypic targets, and structural proteins. The images are precisely registered and segmented into individual cells nuclear, cytoplasmic and membrane regions and the underlying expression of a given antigen is then quantitatively determined in each compartment by automated algorithms. With the advent of this new tool, we aim to define new prognostic molecular signatures in prostate cancer. Citation Information: Clin Cancer Res 2010;16(14 Suppl):A28.