transforming-growth-factor-beta and Inflammatory-Breast-Neoplasms

Zinc finger E-box binding protein 1 (ZEB1) and ZEB2 induce epithelial-mesenchymal transition (EMT) and enhance cancer progression. However, the global view of transcriptional regulation by ZEB1 and ZEB2 is yet to be elucidated. Here, we identified a ZEB1-regulated inflammatory phenotype in breast cancer cells using chromatin immunoprecipitation sequencing and RNA sequencing, followed by gene set enrichment analysis (GSEA) of ZEB1-bound genes. Knockdown of ZEB1 and/or ZEB2 resulted in the downregulation of genes encoding inflammatory cytokines related to poor prognosis in patients with cancer, including IL6 and IL8, therefore suggesting that ZEB1 and ZEB2 have similar functions in terms of the regulation of production of inflammatory cytokines. Antibody array and ELISA experiments confirmed that ZEB1 controlled the production of the IL-6 and IL-8 proteins. The secretory proteins regulated by ZEB1 enhanced breast cancer cell proliferation and tumor growth. ZEB1 expression in breast cancer cells also affected the growth of fibroblasts in cell culture, and the accumulation of myeloid-derived suppressor cells in tumors in vivo. These findings provide insight into the role of ZEB1 in the progression of cancer, mediated by inflammatory cytokines, along with the initiation of EMT.

Topics: Animals; Base Sequence; Biomarkers, Tumor; Cell Line, Tumor; Cell Proliferation; Chemokines; Culture Media, Conditioned; DNA, Neoplasm; Female; Fibroblasts; Gene Expression Regulation, Neoplastic; Humans; Inflammatory Breast Neoplasms; Mice, Inbred BALB C; Mice, Nude; Myeloid Cells; Paracrine Communication; Phenotype; Signal Transduction; Transforming Growth Factor beta; Zinc Finger E-box Binding Homeobox 2; Zinc Finger E-box-Binding Homeobox 1

Inflammatory breast cancer (IBC) is the deadliest form of breast cancer, presenting as intralymphatic emboli. Emboli within the dermal lymphatic vessels are thought to contribute to rapid metastasis. The lack of appropriate in vitro models has made it difficult to accurately study how IBC emboli metastasize. To date, attempts at creating IBC tumor emboli in vitro have used 3D culture on a solid layer of Matrigel(TM) , which does not resemble the physical properties of the lymphatic system. Dermal lymphatic fluid produces oscillatory fluid shear forces and is 1.5-1.7-fold more viscous than water with a pH range of 7.5-7.7. We have established a method for forming tumor emboli by culturing the IBC cell lines in suspension with either polyethylene glycol- or hyaluronic acid-containing medium and oscillatory fluid shear forces. Non-IBC cells do not form emboli under identical conditions. In vitro IBC emboli were analyzed for expression of markers associated with patient emboli and their ability to undergo invasion. In a direct comparison, the in vitro IBC emboli closely resemble IBC patient emboli with respect to size, composition and E-cadherin expression. Further, cells from the emboli are able to invade in clusters via RhoC GTPase-dependent amoeboid movement. Invasion by clusters of IBC cells is disrupted by exposure to TGFβ. This study provides a biologically relevant in vitro model to accurately grow and study inflammatory breast cancer biology and metastasis.

Topics: Blotting, Western; Cadherins; Cell Line, Tumor; Dermis; Female; Gene Expression Regulation, Neoplastic; GTP Phosphohydrolases; Humans; Immunohistochemistry; In Situ Nick-End Labeling; Inflammatory Breast Neoplasms; Lymph Nodes; Lymphatic Metastasis; Lymphatic Vessels; Neoplasm Invasiveness; Neoplastic Cells, Circulating; Receptors, Transforming Growth Factor beta; rho GTP-Binding Proteins; rhoC GTP-Binding Protein; Signal Transduction; Transforming Growth Factor beta

Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Cadherins; Carboplatin; Carcinoma, Ductal, Breast; Chemotherapy, Adjuvant; Clinical Trials as Topic; Diagnosis, Differential; Docetaxel; Drug Resistance, Neoplasm; Female; Humans; Inflammatory Breast Neoplasms; Lapatinib; Mastitis; Molecular Targeted Therapy; Neoadjuvant Therapy; Neoplasm Staging; Neoplastic Cells, Circulating; Quinazolines; Receptor, ErbB-2; Remission Induction; Taxoids; Transforming Growth Factor beta; Trastuzumab; Treatment Outcome