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Biomedical subjects

Matt van de Rijn

Publications and source records attributed to Matt van de Rijn.

14 recordsLinked to original sources

Functional Mapping of Epigenomic Regulators Uncovers Coordinated Tumor Suppression by the HBO1 and MLL1 Complexes.

UNLABELLED: Epigenomic dysregulation is widespread in cancer. However, the specific epigenomic regulators and the processes they control to drive cancer phenotypes are poorly understood. We used a novel high-throughput in vivo method to perform iterative functional screens of >250 epigenomic regulators within autochthonous oncogenic Kras-driven lung tumors. We identified many previously unappreciated epigenomic tumor suppressor and tumor dependency genes. We show that a specific HBO1 complex and MLL1 complex are robust tumor suppressors in lung adenocarcinoma. Histone modifications generated by the HBO1 complex are frequently reduced in human lung adenocarcinomas and are associated with worse clinical features. HBO1 and MLL1 complexes co-occupy shared genomic regions, affect chromatin accessibility, and control the expression of canonical tumor suppressor genes and lineage fidelity. The HBO1 complex is epistatic with the MLL1 complex and other tumor suppressor genes in lung adenocarcinoma development. Collectively, these results provide a phenotypic roadmap of epigenomic regulators in lung tumorigenesis in vivo. SIGNIFICANCE: Using a novel functional genomics method in vivo, we investigated epigenomic regulators in lung tumorigenesis. We discovered multiple novel genes that affect tumor growth. We show that the HBO1 and MLL1 complexes interact to suppress lung adenocarcinoma. Our findings provide broad insights into the epigenomic regulatory landscape of lung cancer.

Humans↗

Endothelial cell diversity revealed by global expression profiling.

The vascular system is locally specialized to accommodate widely varying blood flow and pressure and the distinct needs of individual tissues. The endothelial cells (ECs) that line the lumens of blood and lymphatic vessels play an integral role in the regional specialization of vascular structure and physiology. However, our understanding of EC diversity is limited. To explore EC specialization on a global scale, we used DNA microarrays to determine the expression profile of 53 cultured ECs. We found that ECs from different blood vessels and microvascular ECs from different tissues have distinct and characteristic gene expression profiles. Pervasive differences in gene expression patterns distinguish the ECs of large vessels from microvascular ECs. We identified groups of genes characteristic of arterial and venous endothelium. Hey2, the human homologue of the zebrafish gene gridlock, was selectively expressed in arterial ECs and induced the expression of several arterial-specific genes. Several genes critical in the establishment of left/right asymmetry were expressed preferentially in venous ECs, suggesting coordination between vascular differentiation and body plan development. Tissue-specific expression patterns in different tissue microvascular ECs suggest they are distinct differentiated cell types that play roles in the local physiology of their respective organs and tissues.

Cells, Cultured↗

Gene expression patterns in ovarian carcinomas.

We used DNA microarrays to characterize the global gene expression patterns in surface epithelial cancers of the ovary. We identified groups of genes that distinguished the clear cell subtype from other ovarian carcinomas, grade I and II from grade III serous papillary carcinomas, and ovarian from breast carcinomas. Six clear cell carcinomas were distinguished from 36 other ovarian carcinomas (predominantly serous papillary) based on their gene expression patterns. The differences may yield insights into the worse prognosis and therapeutic resistance associated with clear cell carcinomas. A comparison of the gene expression patterns in the ovarian cancers to published data of gene expression in breast cancers revealed a large number of differentially expressed genes. We identified a group of 62 genes that correctly classified all 125 breast and ovarian cancer specimens. Among the best discriminators more highly expressed in the ovarian carcinomas were PAX8 (paired box gene 8), mesothelin, and ephrin-B1 (EFNB1). Although estrogen receptor was expressed in both the ovarian and breast cancers, genes that are coregulated with the estrogen receptor in breast cancers, including GATA-3, LIV-1, and X-box binding protein 1, did not show a similar pattern of coexpression in the ovarian cancers.

Adenocarcinoma↗

Gene expression patterns in renal cell carcinoma assessed by complementary DNA microarray.

Renal cell carcinoma comprises several histological types with different clinical behavior. Accurate pathological characterization is important in the clinical management of these tumors. We describe gene expression profiles in 41 renal tumors determined by using DNA microarrays containing 22,648 unique cDNAs representing 17,083 different UniGene Clusters, including 7230 characterized human genes. Differences in the patterns of gene expression among the different tumor types were readily apparent; hierarchical cluster analysis of the tumor samples segregated histologically distinct tumor types solely based on their gene expression patterns. Conventional renal cell carcinomas with clear cells showed a highly distinctive pattern of gene expression. Papillary carcinomas formed a tightly clustered group, as did tumors arising from the distal nephron and the normal kidney samples. Surprisingly, conventional renal cell carcinomas with granular cytoplasm were heterogeneous, and did not resemble any of the conventional carcinomas with clear cytoplasm in their pattern of gene expression. Characterization of renal cell carcinomas based on gene expression patterns provides a revised classification of these tumors and has the potential to supply significant biological and clinical insights.

Adenocarcinoma, Clear Cell↗

Gene expression profiles of cutaneous B cell lymphoma.

We studied gene expression profiles of 17 cutaneous B cell lymphomas that were collected with 4-6 mm skin punch biopsies. We also included tissue from two cases of mycosis fungoides, three normal skin biopsies, and three tonsils to create a framework for further interpretation. A hierarchical cluster algorithm was applied for data analysis. Our results indicate that small amounts of skin tissue can be used successfully to perform microarray analysis and result in distinct gene expression patterns. Duplicate specimens clustered together demonstrating a reproducible technique. Within the cutaneous B cell lymphoma specimens two specific B cell differentiation stage signatures of germinal center B cells and plasma cells could be identified. Primary cutaneous follicular and primary cutaneous diffuse large B cell lymphomas had a germinal center B cell signature, whereas a subset of marginal zone lymphomas demonstrated a plasma cell signature. Primary and secondary follicular B cell lymphoma of the skin were closely related, despite previously reported genetic and phenotypic differences. In contrast primary and secondary cutaneous diffuse large B cell lymphoma were less related to each other. This pilot study allows a first glance into the complex and unique microenvironment of B cell lymphomas of the skin and provides a basis for future studies, which may lead to the identification of potential histologic and prognostic markers as well as therapeutic targets.

Adult↗

Expression of FKBP12 in benign and malignant vascular endothelium: an immunohistochemical study on conventional sections and tissue microarrays.

FKBP12 is a cytosolic FK506 binding protein that interacts with calcineurin and thereby mediates the immunosuppressive effects of FK506. Because initial immunohistochemical staining showed abundant expression of FKBP12 in vascular endothelial cells, we evaluated whether it could serve as a marker for vascular neoplasms. We performed immunohistochemical staining of conventional sections from formalin-fixed, paraffin-embedded tissue from 59 benign and malignant vascular neoplasms using a polyclonal rabbit antiserum against FKBP12. Western blot analysis of tissue from 6 angiosarcomas showed a single band at 12 kD, consistent with the published molecular weight for the FKBP12 protein. Together, CD31, CD34, and FKBP12 identified all 59 vascular neoplasms in this study. Specificity of immunohistochemical staining was assessed on 1,321 tissues represented on 7 tissue microarrays. All proteins were occasionally expressed in non-vascular tissue. Six of 8 vascular neoplasms represented on the arrays stained for FKBP12, as did normal vessels in numerous cores. The polyclonal antiserum shows comparable sensitivity (94.9%) and specificity (96.5%) to CD34 and CD31 and may be a useful additional marker for vascular differentiation. Because we have evaluated a large number of tissues by tissue microarray, we anticipate that our estimate of the specificity of immunostaining for FKBP12 as a marker for vascular endothelium will be accurate. In addition, our findings may explain the toxic effects of FK506 on vascular endothelium of the kidney.

Animals↗

Hep par 1 antibody stain for the differential diagnosis of hepatocellular carcinoma: 676 tumors tested using tissue microarrays and conventional tissue sections.

A well-characterized positive marker for hepatocellular differentiation would be a useful tool for the diagnosis of hepatocellular carcinoma (HCC). The recently commercially available Hep Par 1 antibody (clone OCH1E5.2.10) has been reported to be a sensitive marker for HCC in paraffin embedded sections. Of non-hepatocellular tumors, occasional carcinomas have been reported to stain, most frequently gastric adenocarcinomas. This study further evaluated the staining of this antibody on a large number of neoplasms using tissue microarray technology as well as conventional tissue sections. Six hundred seventy-six tumors, including 19 cases of HCC, were tested. Eighteen of 19 cases of HCC were positive, 3 showing <5% staining. Two cases negative on the array showed focal staining when whole tissue sections from the same tumors were used. 16 of 34 cases of gastric carcinomas gave positive reactions, 4 of these showed less than 5% staining. Staining of gastric carcinomas was not limited to signet ring-type carcinomas or to areas of hepatoid differentiation. Only 1 of 11 cases of cholangiocarcinoma showed focal staining. We also noted several other tumors to stain occasionally, including adrenal cortical carcinoma (3/13), yolk sac tumor (2/9), colonic adenocarcinoma (8/106), lung carcinoma (3/52), ovarian carcinoma (5/48), and endocervical adenocarcinoma (1/5). We did not observe staining in pancreatic carcinoma (11), renal cell carcinoma (36), breast carcinoma (85), melanoma (25), or mesothelioma (5). This study supports Hep Par 1 as a useful marker in the differential diagnosis of HCC, but with significant limitations. Cautious use of this antibody in a panel with other positive (alpha fetoprotein, CD10, polyclonal carcinoembryonic antigen) and negative (epithelial membrane antigen, monoclonal carcinoembryonic antigen, CD15) markers of hepatocellular differentiation may aid in the accurate diagnosis of HCC.

Antibodies, Monoclonal↗

Immunohistochemical profile of the sodium/iodide symporter in thyroid, breast, and other carcinomas using high density tissue microarrays and conventional sections.

Extrathyroidal cancers could potentially be targeted with (131)I, if the Na(+)/I(-) symporter (NIS) were functional. Using immunohistochemical methods we probed 1278 human samples with anti-NIS antibody, including 253 thyroid and 169 breast conventional whole tissue sections (CWTS). Four high density tissue microarrays containing a wide variety of breast lesions, normal tissues, and carcinoma cores were tested. The results of the normal microarray were corroborated in 50 CWTS. Nineteen of 34 normal tissues, including bladder, colon, endometrium, kidney, prostate, and pancreas, expressed NIS. Nineteen of 25 carcinomas demonstrated NIS immunopositivity; 55.7% of 479 carcinoma microarray cores expressed NIS, including prostate (74%), ovary (73%), lung (65%), colon (62.6%), and endometrium (56%). NIS protein was present in 75% benign thyroid lesions, 73% thyroid cancers, 30% normal-appearing, peritumoral breasts, 88% ductal carcinomas in situ, and 76% invasive breast carcinoma CWTS. Comparatively, breast microarray cores had lower immunoreactivity. Plasma membrane immunopositivity was confirmed in thyrocytes, salivary ductal, gastric mucosa, and lactating mammary cells. In other tissues, immunoreactivity was predominantly intracellular, particularly in malignant lesions. Thus, NIS is present in many normal epithelial tissues and is predominantly expressed intracellularly in many carcinomas. Elucidating the regulatory mechanisms that render NIS functional in extrathyroidal carcinomas may make (131)I therapy feasible.

Breast Neoplasms↗

Diversity, topographic differentiation, and positional memory in human fibroblasts.

A fundamental feature of the architecture and functional design of vertebrate animals is a stroma, composed of extracellular matrix and mesenchymal cells, which provides a structural scaffold and conduit for blood and lymphatic vessels, nerves, and leukocytes. Reciprocal interactions between mesenchymal and epithelial cells are known to play a critical role in orchestrating the development and morphogenesis of tissues and organs, but the roles played by specific stromal cells in controlling the design and function of tissues remain poorly understood. The principal cells of stromal tissue are called fibroblasts, a catch-all designation that belies their diversity. We characterized genome-wide patterns of gene expression in cultured fetal and adult human fibroblasts derived from skin at different anatomical sites. Fibroblasts from each site displayed distinct and characteristic transcriptional patterns, suggesting that fibroblasts at different locations in the body should be considered distinct differentiated cell types. Notable groups of differentially expressed genes included some implicated in extracellular matrix synthesis, lipid metabolism, and cell signaling pathways that control proliferation, cell migration, and fate determination. Several genes implicated in genetic diseases were found to be expressed in fibroblasts in an anatomic pattern that paralleled the phenotypic defects. Finally, adult fibroblasts maintained key features of HOX gene expression patterns established during embryogenesis, suggesting that HOX genes may direct topographic differentiation and underlie the detailed positional memory in fibroblasts.

Cell Differentiation↗

Molecular characterisation of soft tissue tumours: a gene expression study.

BACKGROUND: Soft-tissue tumours are derived from mesenchymal cells such as fibroblasts, muscle cells, or adipocytes, but for many such tumours the histogenesis is controversial. We aimed to start molecular characterisation of these rare neoplasms and to do a genome-wide search for new diagnostic markers. METHODS: We analysed gene-expression patterns of 41 soft-tissue tumours with spotted cDNA microarrays. After removal of errors introduced by use of different microarray batches, the expression patterns of 5520 genes that were well defined were used to separate tumours into discrete groups by hierarchical clustering and singular value decomposition. FINDINGS: Synovial sarcomas, gastrointestinal stromal tumours, neural tumours, and a subset of the leiomyosarcomas, showed strikingly distinct gene-expression patterns. Other tumour categories--malignant fibrous histiocytoma, liposarcoma, and the remaining leiomyosarcomas--shared molecular profiles that were not predicted by histological features or immunohistochemistry. Strong expression of known genes, such as KIT in gastrointestinal stromal tumours, was noted within gene sets that distinguished the different sarcomas. However, many uncharacterised genes also contributed to the distinction between tumour types. INTERPRETATION: These results suggest a new method for classification of soft-tissue tumours, which could improve on the method based on histological findings. Large numbers of uncharacterised genes contributed to distinctions between the tumours, and some of these could be useful markers for diagnosis, have prognostic significance, or prove possible targets for treatment.

Gene Expression Profiling↗

Software tools for high-throughput analysis and archiving of immunohistochemistry staining data obtained with tissue microarrays.

The creation of tissue microarrays (TMAs) allows for the rapid immunohistochemical analysis of thousands of tissue samples, with numerous different antibodies per sample. This technical development has created a need for tools to aid in the analysis and archival storage of the large amounts of data generated. We have developed a comprehensive system for high-throughput analysis and storage of TMA immunostaining data, using a combination of commercially available systems and novel software applications developed in our laboratory specifically for this purpose. Staining results are recorded directly into an Excel worksheet and are reformatted by a novel program (TMA-Deconvoluter) into a format suitable for hierarchical clustering analysis or other statistical analysis. Hierarchical clustering analysis is a powerful means of assessing relatedness within groups of tumors, based on their immunostaining with a panel of antibodies. Other analyses, such as generation of survival curves, construction of Cox regression models, or assessment of intra- or interobserver variation, can also be done readily on the reformatted data. Finally, the immunoprofile of a specific case can be rapidly retrieved from the archives and reviewed through the use of Stainfinder, a novel web-based program that creates a direct link between the clustered data and a digital image database. An on-line demonstration of this system is available at http://genome-www.stanford.edu/TMA/explore.shtml.

Cluster Analysis↗

Expression of cytokeratins 17 and 5 identifies a group of breast carcinomas with poor clinical outcome.

While several prognostic factors have been identified in breast carcinoma, the clinical outcome remains hard to predict for individual patients. Better predictive markers are needed to help guide difficult treatment decisions. In a previous study of 78 breast carcinoma specimens, we noted an association between poor clinical outcome and the expression of cytokeratin 17 and/or cytokeratin 5 mRNAs. Here we describe the results of immunohistochemistry studies using monoclonal antibodies against these markers to analyze more than 600 paraffin-embedded breast tumors in tissue microarrays. We found that expression of cytokeratin 17 and/or cytokeratin 5/6 in tumor cells was associated with a poor clinical outcome. Moreover, multivariate analysis showed that in node-negative breast carcinoma, expression of these cytokeratins was a prognostic factor independent of tumor size and tumor grade.

Animals↗

Tissue microarrays are an effective quality assurance tool for diagnostic immunohistochemistry.

There has been considerable variability in the reported results of immunohistochemical staining for some diagnostically relevant antigens. Our objectives in this study were to (1) use a multitumor tissue microarray with tissue from 351 cases received in our department, representing 16 normal tissues and 47 different tumor types, to compare immunohistochemical staining results in our laboratory with published data, using a panel of 22 antibodies; (2) assess interlaboratory variability of immunohistochemical staining for S-100 using this microarray; and (3) test the ability of hierarchical clustering analysis to group tumors by primary site, based on their immunostaining profile. Tissue microarrays consisting of duplicate 0.6-mm cores from blocks identified in the hospital archives were constructed and stained according to our usual protocols. Antibodies directed against the following antigens were used: B72.3, bcl-2, carcinoembryonic antigen, c-kit, pankeratin, CD 68, CD 99, CK 5/6, CK 7, CK 8/18, CK19, CK 20, CK 22, epithelial membrane antigen, estrogen receptor, melan-A, p53, placental alkaline phosphatase, S-100, synaptophysin, thyroid transcription factor-1, and vimentin. Staining results on the array cases were compared with published results, and hierarchical clustering analysis was performed based on the immunohistochemical staining results. Unstained slides of the multitumor tissue microarray were sent to five other diagnostic immunohistochemistry laboratories and stained for S-100 protein. The staining results from the different laboratories were compared. Staining results using our current methods and samples from our laboratory were compatible with those described in the literature for most antigens. Placental alkaline phosphatase staining was not specific with our protocol, showing staining of a broad spectrum of different tumors; this finding initiated a review of our recent requests for placental alkaline phosphatase immunostaining and revealed two instances in which placental alkaline phosphatase positivity was incorrectly interpreted as evidence of a germ cell tumor. S-100 staining was less sensitive but more specific for the diagnosis of melanoma or neural tumor in our laboratory, compared to some published reports. Assessment of interlaboratory variability of S-100 immunostaining showed that there was more frequent staining of carcinomas in some laboratories, resulting in decreased specificity of S-100 staining in distinguishing melanoma from carcinoma. Hierarchical clustering analysis showed a strong trend for tumors to cluster by tissue of origin, but there were significant exceptions. We conclude that multiple-tumor microarrays are an efficient method for assessing the sensitivity and specificity of staining with any antibody used diagnostically. As a tool for quality assurance, they offer the advantage of taking into account local differences in tissue fixation, processing, and staining. They also allow cost-effective assessment of interlaboratory variability in immunohistochemical staining. Results of hierarchical clustering analysis show the potential for panels of immunohistochemical stains to identify the primary site of metastatic carcinomas but also confirm the limitations of currently available antibodies in giving unequivocal tissue-specific staining patterns.

Biomarkers, Tumor↗