Comparative genomic hybridization (CGH) using 40 cell lines derived from malignant melanomas (MMs) revealed frequent amplification at 7q33-q34 containing BRAF gene, which often is mutated in MM. We found this gene to be amplified to a remarkable degree in the MM cell lines that exhibited high-level gains at 7q33-q34 in CGH. Among 40 cell lines, the eight lines that revealed neither BRAF nor NRAS mutations showed even higher levels of BRAF mRNA expression than the 32 mutated lines, although DNA amplification at 7q33-q34 was not detected in every lines overexpressing BRAF. MM cells that carried wild-type BRAF and NRAS showed constitutive overexpression of B-Raf protein and phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), even after serum starvation. Not only downregulation of the endogenously overexpressed wild-type B-Raf by antisense oligonucleotide but also a treatment with an inhibitor of mitogen-activated protein kinase kinase (MAPKK, MEK) reduced phosphorylated ERK1/2 and cell growth, whereas the exogenously expressed wild-type B-Raf promoted cell growth in MM cells. Our results provide the evidence that overexpression of wild-type B-Raf, in part but not always as a result of gene amplification, is one of the mechanisms underlying constitutive activation of the MAPK pathway that stimulates growth of MM cells.

The question of whether any genetic differences exist between primary and colorectal cancers (CRCs) and their metastatic foci is controversial. To look for genetic aberrations involved in metastasis of CRCs to the liver, we performed subtractive comparative genomic hybridization (CGH) experiments using paired samples from 20 CRC patients with primary tumors and synchronous or metachronous liver metastases. Relatively frequent gains in DNA copy number were detected at 6p, suggesting the presence of one or more metastasis-related genes in the region. Analysis of 11 CRC cell lines using array-based CGH (CGH-array) revealed one 6p candidate gene, CCND3. Quantitative reverse transcriptase-polymerase chain reaction experiments showed that CCND3 was significantly upregulated in liver-metastatic lesions compared with primary lesions (Po0.0152). In addition, immunohistochemical analysis of 120 primary CRC tumors demonstrated that cyclin D3 expression in the region of rolled edge was significantly associated with total recurrence, especially hematogenous recurrence (P ¼ 0.0307). The results implied involvement of cyclin D3 in liver metastasis of CRC, and the data may contribute to the development of a novel therapy or diagnostic agent for this currently intractable disease. Our experiments also confirmed the power of subtractive CGH and CGH-array analysis for identifying cancer-related genes.

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Single-incision laparoscopic-assisted percutaneous endoscopic gastrostomy (SILAPEG) was performed in three consecutive patients in whom conventional percutaneous endoscopic gastrostomy (PEG) could not be performed. The mean operation time was 64 min, and the mean blood loss was 2 ml. There were no perioperative complications. The mean interval to the commencement of enteral nutrition through the gastrostomy tube was 3.3 days. Recently, LAPEG has come to be recognized as a safe and useful procedure. Based on our experience, SILAPEG might be one of the safest and most useful methods for performing gastrostomy, especially in cases where conventional PEG is difficult.