RESUMO
Anaplastic large cell lymphomas (ALCL) are characterised by the presence of CD30-positive large cells, which usually are of T-cell type. Based on the presence or absence of translocations involving the anaplastic lymphoma kinase (ALK) locus, ALCL cases can be divided into two groups. To gain more insight in the biology of ALCL, we applied serial analysis of gene expression (SAGE) on the Karpas299 cell line and identified 25 up- and 19 downregulated genes. Comparison of the differentially expressed genes with DNA copy number changes in Karpas299 revealed that two overexpressed genes, S100A10 and S100A11, were located in an amplicon suggesting that the increased mRNA levels were caused by DNA amplification. Quantitative reverse transcription polymerase chain reaction on 5 ALCL cell lines and 12 ALCL tissues confirmed the SAGE data for 13 out of 14 up- and one out of four downregulated genes. Immunohistochemical staining confirmed the presence of S100A10, a calcium-binding protein, in three out of five ALK+ and all 7 ALK- ALCL cases. S100A11 staining was confirmed in all ALK+ and six of seven ALK- ALCL cases. Three of the upregulated genes represented calcium-binding proteins, which suggest that altered intracellular signaling might be associated with the oncogenesis of ALCL.
Assuntos
Anexina A2/genética , Sinalização do Cálcio/genética , Calmodulina/genética , Regulação Neoplásica da Expressão Gênica , Linfoma Difuso de Grandes Células B/genética , Proteínas S100/genética , Anexina A2/análise , Linfócitos T CD4-Positivos/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Regulação para Baixo , Galectina 1/análise , Galectina 1/genética , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica/métodos , Linfoma Difuso de Grandes Células B/metabolismo , Proteínas de Membrana/genética , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas S100/análiseRESUMO
Anaplastic large cell lymphomas (ALCLs) can be subdivided into two subgroups on the basis of their expression of the ALK protein. ALK protein expression leads to activation of signal transducer and activator of transcription (STAT) 3, which is more commonly expressed in ALK-positive than in ALK-negative tumours. Activated STAT3 leads to the induction of several genes such as Mcl-1, Bcl-2 and Bcl-X(L), and tissue inhibitor of metalloproteinase (TIMP)-1. In this study, we analysed TIMP-1 expression in five ALCL cell lines and 11 tumours by quantitative RT-PCR and immunohistochemistry. We identified high-level TIMP-1 expression by RT-PCR in three ALK-positive ALCL-derived cell lines and in all ALK-positive ALCLs, whereas ALK-negative ALCLs generally demonstrated a lower level of TIMP-1 expression. Concordant with these results, we observed TIMP-1 immunostaining in all ALK-positive ALCLs and in only two of six ALK-negative ALCLs. No relationship was observed between the levels of ALK and TIMP-1 expression in the ALK-positive tumours. STAT3 expression levels were similar in all ALCL samples. Double staining with either CD30 or CD68 demonstrated that TIMP-1 expression was restricted to macrophages in the majority of TIMP-1-positive tumours. Expression of the TIMP-1 substrate MMP-2 was more prominent in ALK-negative tumours, while MMP-9 levels were low in all cases. Expression levels of IL-6 and TGF-beta1, which are cytokines known to induce TIMP-1, were higher in ALK-negative ALCLs and moderate in ALK-positive tumours. No clear relationship was observed between IL-10 expression and ALK positivity. Overall, no correlation was seen in ALCLs between the expression of TIMP-1 and that of cytokines that induce TIMP-1. Lack of TIMP-1 expression in the tumour cells of ALK-positive ALCLs argues against a direct role for ALK-induced activation of STAT3 in the regulation of TIMP-1 expression in ALCL.
Assuntos
Linfoma Difuso de Grandes Células B/química , Macrófagos/química , Inibidor Tecidual de Metaloproteinase-1/análise , Quinase do Linfoma Anaplásico , Antígenos CD/análise , Linhagem Celular Tumoral , Citocinas/análise , Proteínas de Ligação a DNA/análise , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Imuno-Histoquímica/métodos , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Metaloproteinases da Matriz/análise , Proteínas de Neoplasias/análise , Proteínas Tirosina Quinases/análise , Receptores Proteína Tirosina Quinases , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Fator de Transcrição STAT3 , Transativadores/análiseRESUMO
Large cell lymphomas and Hodgkin disease may develop during the course of chronic lymphocytic leukemia (CLL). In some cases the transformed cells are Epstein-Barr virus (EBV)-positive and not clonally related to the CLL cells. In other cases the transformed cells have the same clonal rearrangements as the CLL cells. Here we describe a composite lymphoma in a patient with CLL that exhibits a combination of CLL/small lymphocytic lymphoma, large cell lymphoma with anaplastic morphology, and Hodgkin lymphoma (HL). Although the large cell lymphoma cells are CD45R0 and TIA-1-positive, suggesting a T- or 0-cell anaplastic large cell lymphoma (ALCL), the genetic analysis demonstrates immunoglobulin heavy chain (IgH) gene rearrangements for both alleles, carrying the same somatic mutations as observed in the CLL component. The Reed-Sternberg (R-S) cells in the Hodgkin component also strongly express TIA-1 but differ from the anaplastic large cells by the expression of CD15 and TARC and the presence of a prominent lymphocytic infiltrate. The ALCL and HL components both are EBV negative. Analysis of the IgH gene rearrangements in micromanipulated R-S cells revealed identical Ig gene rearrangements carrying the same somatic mutations as the CLL and the large cell components. The findings indicate transformation of the CLL cells into a large cell lymphoma with anaplastic morphology and a Hodgkin component.
