Molecular cytogenetics of pediatric adipocytic tumors.

Both epidemiologic and cytogenetic data on pediatric adipose tissue tumors are scarce. Pediatric adipose tumors are mainly represented by lipomas, though only 28 cytogenetic descriptions of pediatric lipoma have been reported to date. Similar to adult cases, most of these pediatric lipomas harbored rearrangements of the chromosomal regions 12q14-q15 and 6p21, involving the HMGA2 and HMGA1 genes. Further cytogenetic studies of pediatric lipoma would be useful to determinate whether some partner genes of HMGA2, such as NFIB, may have a specific role in the early onset of these tumors. Cytogenetically, the best documented pediatric adipose tumor is lipoblastoma, which is the second most frequent adipose tumor in children. Chromosomal alterations in lipoblastoma, observed in 61% of cases studied by conventional cytogenetics, typically involve the 8q11-q12 region. The target gene of this rearrangement is PLAG1. Anomalies of PLAG1 have been observed in 70% of cases of pediatric adipose tumors studied by molecular cytogenetics methods, such as fluorescence in situ hybridization (FISH) or comparative genomic hybridization on array (array-CGH). The rare described cases of malignant pediatric adipose tumors in children are mostly myxoid liposarcomas. In the 27 cases explored at the genetic level, all pediatric myxoid liposarcomas showed the classical rearrangement of the DDIT3 gene at 12q13. In conclusion, the epidemiology and the prevalence of histological types of adipose tissue tumors differ in the pediatric population compared with adults, whereas chromosomal and genic rearrangements are similar to those of adult cases in each histological type.

Case Report: Detection and quantification of tumor cells in peripheral blood and ascitic fluid from a metastatic esophageal cancer patient using the CellSearch (®) technology.

Analysis of ascitic fluid should help to identify and characterize malignant cells in gastrointestinal cancer. However, despite a high specificity, the sensitivity of traditional ascitic fluid cytology remains insufficient, at around 60%. Since 2004 the CellSearch (®) technology has shown its advantages in the detection of circulating tumor cells (CTCs) in peripheral blood, which can perform an accurate diagnosis and molecular analysis at the same time. To our knowledge, no previous study has explored the potential utility of this technology for the detection and quantification of tumor cells in ascitic fluid samples. Herein we report a case of metastatic esophageal adenocarcinoma in a 70-year-old man presenting with dysphagia and a large amount of fluid in the peritoneal cavity. Analysis of a peripheral blood sample and ascites sample with the CellSearch (®) technology both revealed the presence of putative tumor cells that were positive for epithelial cell adhesion molecule (EpCAM) and cytokeratin (CK) expression. This study confirmed the hematogenous dissemination of esophageal cancer by the detection of circulating tumor cells in the peripheral blood, and is the first to demonstrate that tumor cells can be identified in ascitic fluid by using CellSearch (®) technology.

C-propeptides of procollagens I alpha 1 and II that differentially accumulate in enchondromas versus chondrosarcomas regulate tumor cell survival and migration.

Chondrogenic tumors that exhibit benign or malignant behaviors synthesize variable amounts of cartilage-like extracellular matrix. To define the regulators of these phenotypes, we performed a proteomic comparison of multiple human chondrogenic tumors, which revealed differential accumulation of the C-propeptides of procollagens Ialpha1 and II (PC1CP and PC2CP) in malignant versus benign tumors, respectively. Expression patterns of PC1CP correlated with levels of tumor vascularization, whereas expression patterns of PC2CP suggested its susceptibility to immobilization within the extracellular matrix. Prompted by these observations, we investigated the functions of recombinant PC1CP and PC2CP in the extracellular matrix in soluble or immobilized states. Each induced beta1 integrin-mediated chondrocyte adhesion by distinct domains and efficacies, suggesting that they initiated distinct signaling pathways. Indeed, immobilized PC2CP, but not PC1CP, induced apoptosis of primary chondrocytes and EAhy926 endothelial cells. In contrast, soluble PC1CP, but not PC2CP, induced the migration of EAhy926 cells and increased vascular endothelial growth factor (VEGF) and CXCR4 expression in chondrocytes. Soluble PC2CP also increased VEGF expression, but along with a more pronounced effect on CXCR4 and matrix metalloproteinase 13 expression. Our findings suggest that PC1CP favors angiogenesis and tumor progression, but that PC2CP acts in a more complex manner, exerting antitumor and antiangiogenic properties through apoptosis induction when immobilized, but progression and metastasis when soluble. In summary, the relative levels of PC1CP and PC2CP and their interactions within the extracellular matrix contribute to tumor progression, angiogenesis, and metastasis in chondrogenic tumors.