title: Crosstalk between B16 melanoma cells and B-1 lymphocytes induces global changes in tumor cell gene expression.
abstract: The analysis of gene expression patterns in cancers has improved the understanding of the mechanisms underlying the process of metastatic progression. However, the acquisition of invasive behavior in melanoma is poorly understood. In melanoma, components of the immune system can contribute to tumor progression, and inflammatory cells can influence almost all aspects of cancer progression, including metastasis. Recent studies have attributed an important role to B-1 cells, a subset of B lymphocytes, in melanoma progression. In vitro interactions between B16 melanoma cells and B-1 lymphocytes lead to increased B16 cell metastatic potential, but the molecular changes induced by B-1 lymphocytes on B16 cells have not yet been elucidated. In this study, we used a microarray approach to assess the gene expression profile of B16 melanoma cells following contact with B-1 lymphocytes (B16B1). The microarray analysis identified upregulation in genes involved with metastatic progression, such as ctss, ccl5, cxcl2 and stat3. RT-qPCR confirmed this increase in mRNA expression in B16B1 samples. As previous studies have indicated that the ERK1/2 MAPK cascade is activated in melanoma cells following contact with B-1 lymphocytes, RT-qPCR was performed with RNA from melanoma cells before and after contacting B-1 cells and untreated or treated with ERK phosphorylation inhibitors. The results showed that the expression of stat3, ctss and cxcl2 increased in B16B1 but decreased following ERK1/2 MAPK inhibition. Ccl5 gene expression increased after contacting B-1 cells and was maintained at the same level following inhibitor treatment. Stat3 was verified and validated at the protein level by Western blot analysis. STAT3 expression was also significantly increased in B16B1, suggesting that this pathway can also contribute to the increased metastatic phenotype observed in our model. These results indicated that B-1 cells induce important global gene expression changes in B16 melanoma cells. We also evaluated the relationship of some of the genes identified as differentially expressed and the ERK1/2 MAPK cascade. This work may have important implications for understanding the role of B-1 lymphocytes and the ERK/MAPK cascade in the metastatic process.
authors.affiliation: Departamento de Ciências Biológicas, Universidade Federal de São Paulo, Campus Diadema, Brazil.
authors.forename: Patricia
authors.initials: P
authors.lastname: Xander
authors.forename: Ronni Rômulo Novaes E
authors.initials: RR
authors.lastname: Brito
authors.forename: Elizabeth Cristina
authors.initials: EC
authors.lastname: Pérez
authors.forename: Jaqueline Maciel
authors.initials: JM
authors.lastname: Pozzibon
authors.forename: Camila Ferreira
authors.initials: CF
authors.lastname: de Souza
authors.forename: Renata
authors.initials: R
authors.lastname: Pellegrino
authors.forename: Viviane
authors.initials: V
authors.lastname: Bernardo
authors.forename: Miriam Galvonas
authors.initials: MG
authors.lastname: Jasiulionis
authors.forename: Mario
authors.initials: M
authors.lastname: Mariano
authors.forename: José Daniel
authors.initials: JD
authors.lastname: Lopes
mesh_terms: D000818:Animals; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002403:Cathepsins / Q000235:genetics; D002450:Cell Communication; D018946:Chemokine CCL5 / Q000235:genetics; D054377:Chemokine CXCL12 / Q000235:genetics; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000235:genetics; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000235:genetics; D008546:Melanoma, Experimental / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D046228:Microarray Analysis; D009362:Neoplasm Metastasis / Q000235:genetics; D050796:STAT3 Transcription Factor / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D018946:Chemokine CCL5; D054377:Chemokine CXCL12; D050796:STAT3 Transcription Factor; D002403:Cathepsins; C028217:cathepsin S
keywords: B-1 cells; Gene expression; Melanoma; Metastases; Microarray