Ayumi Matsuyama

The Tumor Suppressor Gene WWOX at FRA16D Is Involved in Pancreatic Carcinogenesis

Purpose: WWOX (WW domain containing oxidoreductase) is a tumor suppressor gene that maps to the common fragile site FRA16D. We showed previously that WWOX is frequently altered in human lung and esophageal cancers. The purpose of this study was to delineate more precisely the role of WWOX in pancreatic carcinogenesis. Experimental Design: We analyzed 15 paired pancreatic adenocarcinoma samples and 9 pancreatic cancer cell lines for WWOX alterations. Colony assay and cell cycle analysis were also performed to evaluate the role of the WWOX as a tumor suppressor gene. Results: Loss of heterozygosity at the WWOX locus was observed in 4 primary tumors (27%). Methylation analysis showed that site-specific promoter hypermethylation was detected in 2 cell lines (22%) and treatment with the demethylating agent 5-aza-2′-deoxycytidine demonstrated an increase in the expression of WWOX. In addition, 2 primary tumor samples (13%) showed promoter hypermethylation including the position of site-specific methylation. Transcripts missing WWOX exons were detected in 4 cell lines (44%) and in 2 tumor samples (13%). Real-time reverse transcription PCR revealed a significant reduction of WWOX expression in all of the cell lines and in 6 primary tumors (40%). Western blot analysis showed a significant reduction of the WWOX protein in all of the cell lines. Furthermore, transfection with WWOX inhibited colony formation of pancreatic cancer cell lines by triggering apoptosis. Conclusion: These results indicate that the WWOX gene may play an important role in pancreatic tumor development.

Fragile site orthologs FHIT/FRA3B and Fhit/Fra14A2: Evolutionarily conserved but highly recombinogenic

Common fragile sites are regions that show elevated susceptibility to DNA damage, leading to alterations that can contribute to cancer development. FRA3B, located at chromosome region 3p14.2, is the most frequently expressed human common fragile site, and allelic losses at FRA3B have been observed in many types of cancer. The FHIT gene, encompassing the FRA3B region, is a tumor-suppressor gene. To identify the features of FHIT/FRA3B that might contribute to fragility, sequences of the human FHIT and the flanking PTPRG gene were compared with those of murine Fhit and Ptprg. Human and mouse orthologous genes, FHIT and Fhit, are more highly conserved through evolution than PTPRG/Ptprg and yet contain more sequence elements that are exquisitely sensitive to genomic rearrangements, such as high-flexibility regions and long interspersed nuclear element 1s, suggesting that common fragile sites serve a function. The conserved AT-rich high-flexibility regions are the most characteristic of common fragile sites.

Plasma D-dimer level as a mortality predictor in patients with advanced or recurrent colorectal cancer.

Objective: Plasma D-dimer levels are elevated in patients with a variety of solid tumors. Recently, it has been reported that the level before curative surgery is a prognostic factor for colorectal cancer (CRC). We investigated whether the plasma D-dimer level before systemic chemotherapies is a predictor for advanced or recurrent unresectable CRC. Methods: This study included 42 patients treated with systemic chemotherapies for advanced or recurrent unresectable CRC. Variables including clinicopathological factors, plasma D-dimer levels and the modified Glasgow Prognostic Factor Score (mGPS) were evaluated. Results: The plasma D-dimer level was closely related to the mGPS. Survival was shorter for patients with plasma D-dimer levels >5 µg/ml than for those with lower levels. Compared with an mGPS of 0 or 1, an mGPS of 2 was predictive of poor prognosis (p < 0.0001). Old age, advanced stage, plasma D-dimer level and mGPS were significantly associated with mortality, but plasma D-dimer level was the only independent risk factor in multivariate analysis, and was significant related to the clinical response to chemotherapy (p < 0.05). Conclusions: Survival was significantly shorter in patients with elevated plasma D-dimer levels having advanced or recurrent CRC. The plasma D-dimer level before systemic chemotherapies was an independent mortality predictor.

Common fragile genes

Common chromosome fragile sites show susceptibility to DNA damage, leading to alterations that contribute to cancer development. The cloning and characterization of fragile sites have demonstrated that fragile sites are associated with genes that relate to tumorigenesis. Identification of the basis of instability at fragile sites and the related genes provides an entree to understanding of important aspects of chromosomal instability, a prominent feature of neoplastic genomes. FHIT/FRA3B and WWOX/FRA16D, the most sensitive common fragile genes in the human genome, function as tumor suppressor genes. The common features of these two common fragile genes are summarized, and suggest clues to understanding the relation between genomic instability and tumor biology.

Xanthogranulomatous cholecystitis: importance of chemical-shift gradient-echo MR imaging

Accepted: 27 September 2002 Published online: 13 February 2003

Outcome of hepatectomy in hepatocellular carcinoma patients aged 80 years and older

BACKGROUND/AIMS The aim of this retrospective study was to determine the effect of age on the outcome of hepatic resection in octogenarian patients with hepatocellular carcinoma (HCC). METHODOLOGY Data of 408 consecutive primary HCC patients who underwent curative hepatectomy were studied. The surgical results of the younger group (<80 years of age) and the elderly group (≥80 years of age) were compared. RESULTS Preoperative parameters, such as comorbid conditions and liver function tests, of the younger group (n=385) were comparable with those of the elderly group (n=23). Surgical data and the prevalence of postoperative complications did not differ significantly between the two groups. The long-term prognosis of the elderly group patients was almost identical to that of the younger group patients. Overall 3-year survival rates for the elderly group and the younger group were 95.7% vs. 84.8%, respectively (p=0.56). Disease-free three-year survival rates for the elderly group and the younger group were 47.2% vs. 47.7%, respectively (p=0.65). CONCLUSIONS Hepatectomy is a viable treatment alternative with satisfactory surgical outcome for HCC even in patients aged 80 years or older.

Microsatellite Instability Is Often Observed in Esophageal Carcinoma Patients with Allelic Loss in the FHIT/FRA3B Locus

We have previously reported a significant correlation between the progression of colorectal carcinoma and the loss of Fhit and Msh2 expression. This observation led us to investigate the effect of an allelic loss of the FHIT gene on esophageal cancer when coupled with a deficient mismatch repair system. In this study, 8 of 42 patients with esophageal cancer had microsatellite instability (MSI), and 29 cases demonstrated allelic loss (loss of heterozygosity or homozygous deletion) at the FHIT/FRA3B locus. All 8 MSI-positive cases showed allelic loss, while 13 of 34 MSI-negative cases retained both alleles, and a significant correlation was found between the incidence of MSI and allelic loss (p < 0.05). On the other hand, only 1 of the 8 MSI-positive patients exhibited neither Msh2 nor Fhit protein expression in both normal and carcinoma epithelial tissues, but neither a relationship between Msh2 expression and Fhit expression nor with the incidence of MSI was noted. This result indicated that the disruption of the mismatch repair system of Msh2 does not mainly lead to allelic loss of the FHIT/FRA3B locus as well as MSI in esophageal cancer. We concluded that MSI is significantly related to the allelic loss in the FHIT/FRA3B region, but Msh2 might be unrelated to the progression or oncogenic process in esophageal cancer.

L‐myc Restriction Fragment Length Polymorphism in Japanese Patients with Esophageal Cancer

L‐myc polymorphism is a representative genetic trait related to an individuals susceptibility to several cancers. However, there have been no reports concerning the association between esophageal cancer and L‐myc polymorphism. To analyze the distribution of polymorphism in Japanese patients with esophageal cancer, a molecular genotyping method using a polymerase chain reaction‐based restriction fragment length polymorphism (PCR‐RFLP) was used. Based on an analysis of 65 Japanese patients with esophageal cancer and 107 healthy control subjects, a significant difference was observed in either the distribution of genotypes (P=0.012) or of allele frequencies between the two groups (P 0.004). The relative risk of esophageal cancer for genotypes including the shorter allele was 2.9 compared to the longer allele homozygote. Furthermore, the patients with S‐allele had a tendency for poor prognosis among those with three genotypes. A significant difference between the distribution of genotypes and the incidence of lymph node metastasis was found based on the clinicopathological features of the cancers. These results suggest that L‐myc polymorphism may be implicated as a genetic trait affecting an individuals susceptibility to esophageal cancer, at least among Japanese patients.

Secondary c-kit Mutation in a Recurrent Gastrointestinal Stromal Tumor Under Long-Term Treatment with Imatinib Mesylate: Report of a Case

Gastrointestinal stromal tumors (GISTs) commonly harbor oncogenic mutations of the c-kit receptor gene, which are targets for imatinib mesylate. However, imatinib resistance is an increasing clinical problem. We herein present such a case with a recurrent GIST, in association with the development of a secondary mutation in the c-kit gene. A 67-year-old man, who had a GIST of the stomach with multiple liver metastases, underwent a partial gastrectomy, distal pancreatectomy, and partial hepatectomy. After surgery, he was treated with imatinib. However, during the approximately 4-year treatment period, a recurrence of the GIST in the liver was detected, for which a partial hepatectomy was again performed. The primary GIST constitutively had a deletion mutation in exon 11. In addition, the recurrent hepatic tumor developed a secondary point mutation (Val654Ala) in exon 13, which may be responsible for the imatinib resistance.

Surgery after Preoperative Chemotherapy for Patients with Unresectable Advanced Gastric Cancer

Objective: The study aimed to evaluate the efficacy of surgery after preoperative chemotherapy for unresectable advanced gastric cancer. Method: Twenty patients with disappeared peritoneal dissemination or decreased lymph node metastasis by systemic chemotherapy underwent surgery (group S), while 14 with peritoneal dissemination or lymph nodes >N2 (group C) received continuous systemic chemotherapy. Among group S patients, 15 underwent a curative resection (group R0), while the other 5 did not microscopically undergo a curative resection (group R1). Results: The median survival time for all patients was 535 days. Survival time was significantly dependent on the chemotherapy response (p < 0.002). The survival period in group S was significantly longer than that in group C (median survival time 747 vs. 476 days; p < 0.02). The relapse-free survival was 299 days in group S. In particular, the survival period of patients who underwent R0 surgery by preoperative chemotherapy was significantly longer than that of group R1 patients (median survival time 794 vs. 485 days; p < 0.02). Multivariate analysis revealed that R0 surgery was a significant and independent prognostic factor. Conclusion: Surgery was effective for advanced gastric cancer patients when performed as R0 resection following the disappearance of non-curative factors by preoperative chemotherapy.