title: Adhesive interactions regulate transcriptional diversity in malignant B cells.
abstract: The genetic profiling of B-cell malignancies is rapidly expanding, providing important information on the tumorigenic potential, response to treatment, and clinical outcome of these diseases. However, the relative contributions of inherent gene expression versus microenvironmental effects are poorly understood. The regulation of gene expression programs by means of adhesive interactions was studied here in ARH-77 human malignant B-cell variants, derived from the same cell line by selective adhesion to a fibronectin matrix. The populations included cells that adhere to fibronectin and are highly tumorigenic (designated "type A" cells) and cells that fail to adhere to fibronectin and fail to develop tumors in vivo ("type F" cells). To identify genes directly affected by cell adhesion to fibronectin, type A cells deprived of an adhesive substrate (designated "AF cells") were also examined. Bioinformatic analyses revealed a remarkable correlation between cell adhesion and both B-cell differentiation state and the expression of multiple myeloma (MM)-associated genes. The highly adherent type A cells expressed higher levels of NFkappaB-regulated genes, many of them associated with MM. Moreover, we found that the transcription of several MM-related proto-oncogenes is stimulated by adhesion to fibronectin. In contrast, type F cells, which display poor adhesive and tumorigenic properties, expressed genes associated with higher levels of B-cell differentiation. Our findings indicate that B-cell differentiation, as manifested by gene expression profiles, is attenuated by cell adhesion to fibronectin, leading to upregulation of specific genes known to be associated with the pathogenesis of MM.
authors.affiliation: Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Liat
authors.initials: L
authors.lastname: Nadav-Dagan
authors.forename: Tal
authors.initials: T
authors.lastname: Shay
authors.forename: Nili
authors.initials: N
authors.lastname: Dezorella
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Naparstek
authors.forename: Eytan
authors.initials: E
authors.lastname: Domany
authors.forename: Ben-Zion
authors.initials: BZ
authors.lastname: Katz
authors.forename: Benjamin
authors.initials: B
authors.lastname: Geiger
mesh_terms: D001402:B-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D002448:Cell Adhesion / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D005109:Extracellular Matrix / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D008232:Lymphoproliferative Disorders / Q000235:genetics* / Q000378:metabolism* / Q000503:physiopathology; D009101:Multiple Myeloma / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000503:physiopathology; D011519:Proto-Oncogenes / Q000235:genetics; D015533:Transcriptional Activation / Q000235:genetics*
chemical_list: D005353:Fibronectins; D016328:NF-kappa B