福嶋 敬宜

Long standing chronic pancreatitis is a risk factor for developing pancreatic cancer. Inheritance of polymorphisms in SPINK1 and CFTR are associated with an increased risk of developing pancreatitis. The aim of this study was to determine if patients who carry polymorphisms in SPINK1 and CFTR are at increased risk of developing pancreatic cancer through the development of chronic pancreatitis. DNA from patients with histologically confirmed surgically-treated chronic pancreatitis, familial and sporadic pancreatic adenocarcinoma and controls were analyzed for the N34S polymorphism of SPINK1 and the two commonest polymorphisms of the CFTR gene, the DeltaF508 mutation and the 5T polymorphism. These polymorphisms were determined using restriction fragment length polymorphism, PCR and cycle sequencing methods. The SPINK1 N34S polymorphism was detected in 5 of 172 (2.9%) patients with chronic pancreatitis, in 4 of 200 (2.0%) patients with sporadic pancreatic adenocarcinoma, in 0 of 36 (0%) of patients with familial pancreatic cancer and in 3 of 177 (1.7%) controls of chronic cholecystitis. The CFTR 5T polymorphism was identified in 31 of 334 (9.3%) patients of sporadic pancreatic cancer, in 5 of 43 (11.6%) patients with familial pancreatic cancer and in 10 of 112 (8.9%) controls with colorectal cancer. The CFTR DeltaF508 mutation was recognized in 6 of the 240 (2.5%) patients with pancreatic adenocarcinoma, a prevalence similar to that of control populations. We conclude that the N345 polymorphism of SPINK1 and the 5T and DeltaF508 CFTR polymorphisms do not predispose to the development of pancreatic adenocarcinoma. Furthermore, the N34S polymorphism is rarely found in patients with severe idiopathic chronic pancreatitis.

Deregulated expression of SPARC/osteonectin, a secreted glycoprotein with multiple biological functions, has been associated with the progression of various cancers. Using microarrays, we previously identified SPARC as one of the genes induced by treatment with a DNA methylation inhibitor in pancreatic cancer cells. We therefore analysed the expression pattern and methylation status of the SPARC gene in pancreatic cancer. Gene expression profiting by oligonucleotide microarray and reverse transcription-PCR analyses demonstrated that SPARC mRNA was expressed in non-neoplastic pancreatic ductal epithelial cells, but was not expressed in a majority of pancreatic cancer cell lines. The loss of SPARC expression was associated with aberrant hypermethylation of its CpG island. Immunohistochemical labeling revealed that the SPARC protein was overexpressed in the stromal fibroblasts immediately adjacent to the neoplastic epithelium in primary pancreatic cancers, but rarely expressed in the cancers themselves. Primary fibroblasts derived from pancreatic cancer strongly expressed SPARC mRNA and secreted SPARC protein into the conditioned media, and treatment of pancreatic cancer cells with exogenous SPARC resulted in growth suppression. SPARC expression in fibroblasts from noncancerous pancreatic tissue was augmented by coculture with pancreatic cancer cells. These findings suggest that SPARC is a frequent target for aberrant methylation in pancreatic cancer and that SPARC expression in fibroblasts adjacent to pancreatic cancer cells is regulated through tumor-stromal interactions.

To identify potential targets for aberrant methylation in pancreatic cancer, we analyzed global changes in gene expression profiles of four pancreatic cancer cell lines after treatment with the demethylating agent 5-aza-2'-deoxycytidine (5Aza-dC) and/or the histone deacetylase inhibitor trichostatin A. A substantial number of genes were induced 5-fold or greater by 5Aza-dC alone (631 transcripts), trichostatin A alone (1196 transcripts), and by treatment with both agents (857 transcripts). Four hundred and seventy-five genes were markedly (>5-fold) induced after 5Aza-dC treatment in pancreatic cancer cell lines but not in a nonneoplastic pancreatic epithelial cell line. The methylation status of 11 of these 475 genes was examined in a panel of 42 pancreatic cancers, and all 11 of these genes were aberrantly methylated in pancreatic cancer but rarely, if any, methylated in 10 normal pancreatic ductal epithelia. These genes include UCHL1 (methylated in 100% of 42 pancreatic cancers), NPTX2 (98%), SARP2 (95%), CLDN5 (93%), reprimo (86%), LHX1 (76%), WNT7A (71%), FOXE1 (69%), TJP2 (64%), CDH3 (19%), and ST14 (10%). Three of these 11 genes (NPTX2, SARP2, and CLDN5) were selected for further analysis in a larger panel of specimens, and aberrant methylation of at least one of these three genes was detectable in 100% of 43 primary pancreatic cancers and in 18 of 24 (75%) pancreatic juice samples obtained from patients with pancreatic cancer. Thus, a substantial number of genes are induced by 5Aza-dC treatment of pancreatic cancer cells, and many of them may represent novel targets for aberrant methylation in pancreatic carcinoma.

To investigate the relationship between DNA hypomethylation and gene overexpression in pancreatic cancer, we analyzed the methylation status of a subset of 18 genes previously identified by global gene expression studies as overexpressed in pancreatic cancer tissues compared with normal pancreas. For comparison, we determined the methylation status of 14 genes not known to be overexpressed in pancreatic cancer. Methylation-specific PCR analysis revealed that 19 of these 32 genes were methylated at their 5' CpGs in normal pancreas. We then analyzed these 19 genes for their methylation pattern in pancreatic cancers and found that all 7 of the genes (claudin4, lipocalin2, 14-3-3sigma,, trefoil factor2, S100A4, mesothelin, and prostate stem cell antigen) that were overexpressed in the neoplastic cells of pancreatic cancers and not expressed in normal pancreatic duct displayed a high prevalence of hypomethylation in pancreatic cancer cell lines and primary pancreatic carcinomas. By contrast, only 1 of 12 genes not overexpressed in pancreatic cancer demonstrated hypomethylation (P = 0.0002). In pancreatic cancer cell lines that retained methylation of 1 or more of the 7 aforementioned overexpressed and hypomethylated genes, treatment with 5-aza-2'-deoxycytidine or with trichostatin A, either alone or in combination, almost invariably reactivated the transcription of each of these 7 genes. These results indicate that gene hypomethylation is a frequent epigenetic event in pancreatic cancer and is commonly associated with the overexpression of affected genes.

PURPOSE: We describe a rare case of an alpha-fetoprotein-producing carcinoma originating in the transverse colon of a 59-year-old Japanese male. METHODS: The patient reported an abdominal mass and weight loss. On examination, a tumor of the transverse colon and multiple masses in the liver were found. The serum alpha-fetoprotein level was extremely high (12,873 ng/ml). The patient underwent right hemicolectomy and intraoperative biopsy of a liver mass. RESULTS: Histologically, the colon cancer was composed of three different components: a well-differentiated tubular adenocarcinoma, a tubulopapillary carcinoma consisting of cells with clear cytoplasms, and a "hepatoid carcinoma." The hepatoid carcinoma was composed of large polygonal cells with abundant eosinophilic or clear cytoplasms, arranged in a trabecular or solid pattern, and showing marked vascular invasion. Immunohistochemically, alpha-fetoprotein was strongly expressed, largely in the hepatoid carcinoma and partially in the tubulopapillary carcinoma. The liver biopsy specimen showed morphologic and immunohistochemical features similar to those of the hepatoid carcinoma of the colon and was therefore diagnosed as a metastasis. The patient died of the cancer two months after surgery. CONCLUSION: Based on our experience of this patient and a review of the literature, alpha-fetoprotein-producing colorectal carcinomas are generally associated with a poor prognosis because of the frequent occurrence of blood-borne metastases.

Purpose: Hypermethylation of CpG islands in the promoters of selected genes is a common feature of neoplasia. Aberrant methylation of cyclin D2 has been observed in several cancers. We investigated the methylation of cyclin D2 in aging and pancreatic neoplastic development, and the utility of cyclin D2 methylation as a marker of pancreatic adenocarcinoma. Experimental Design: Methylation-specific PCR was performed on DNA from 165 resected pancreatic exocrine neoplasms [109 adenocarcinomas, 46 intraductal papillary-mucinous neoplasms (IPMNs), and 10 mucinous cystic neoplasms], 14 pancreatic intraepithelial neoplasms, 13 micro-dissected-normal pancreatic ductal epithelia, 25 normal pancreatic parenchyma, 51 specimens of pancreatic juice obtained perioperatively, 15 pancreatic cancer xenografts, 22 pancreatic cancer cell lines, 59 specimens of normal duodenum, and 49 gallbladders affected by cholecystitis. Cyclin D2 RNA expression was determined in pancreatic cancer cell lines, before and after 5-AZA-2'-deoxycytidine treatment, by reverse transcription-PCR. Results: Methylation of cyclin D2 was identified in 65.1% (71 of 109) of primary pancreatic adenocarcinomas, in 50% (23 of 46) of IPMNs, and in 70% (7 of 10) of mucinous cystic neoplasms, but was detected infrequently in microdissected samples of normal pancreatic epithelia [7.7% (1 of 13)] and in pancreatic intraepithelial neoplasms [14.3% (2 of 14)]. Cyclin D2 methylation was also recognized in 10 of 15 (66.7%) pancreatic cancer xenografts; and in 19 of 22 (86.4%) pancreatic cancer cell lines. All of 10 pancreatic cancer cell lines completely methylated at cyclin D2 showed no expression by reverse transcription-PCR. Four of these 10 cell lines were treated with 5-AZA-2'-deoxycytidine, and all 4 showed increased RNA expression of cyclin D2 after treatment. In pancreatic juice, cyclin D2 methylation was detected in 9 of 22 (40.9%) samples from patients with pancreatic cancer and in 6 of 9 (66.7%) patients with IPMNs, but in none of 20 non-neoplastic controls, respectively (P = 0.0013 and P < 0.0001, respectively). Methylation of cyclin D2 was also observed more in non-neoplastic tissues and with increasing age (P = 0.041 in the pancreas, P = 0.047 in the duodenum, and P = 0.0008 in the gallbladder). Conclusions: The promoter region of cyclin D2 undergoes age-related methylation in multiple tissues, but aberrant methylation is more often detected in tissues and juice samples of pancreatic cancer than in normal tissues. The detection of cyclin D2 methylation in pancreatic juice may aid in the diagnosis of pancreatic adenocarcinoma.

The aim of this study was to determine the utility of detecting methylated ppENK and p16 in pancreatic juice by methylation specific PCR as a marker of pancreatic adenocarcinoma. Pancreatic juice samples were collected either intraoperatively, from 92 patients undergoing pancreaticoduodenectomy for benign (n = 20) and malignant periampullary disease (n = 72) or endoscopically (by duodenal aspiration after secretin infusion), from 13 patients undergoing investigation for pancreatic disease. Methylated ppENK was detected in the pancreatic juice of 30 (66.7%) of 45 patients with pancreatic ductal adenocarcinoma, in A (44.4%) of 9 patients with intraductal papillary-mucinous adenocarcinoma, and in 7 (41.2%) of 17 patients with other periampullary carcinomas, using methylation specific PCR. Methylated p 16 was detected in a lower percentage of these patients (11.1%, 11.1% and 23.5%, respectively). In contrast, methylated ppENK and p16 were not detected in 20 patients with non-malignant periampullary disease including 12 patients with chronic pancreatitis. Methylated ppENK was detected in 30 of 33 (90.9%) primary pancreatic adenocarcinoma and methylated p16 was in 6/33 (18.2%). Despite the absence of ppENK and p 16 methylation in normal pancreas, methylated ppENK and p 16 was present in the duodenum of 90.5% and 28.6%, respectively of patients without cancer. Further, methylated ppENK and p 16 was seen in 88.9% and 11.1%, respectively of pancreatic juice samples obtained by duodenal aspiration from patients without cancer. We conclude that since ppENK and p16 are not normally methylated in pancreatic secretions, detection of methylated ppENK and p 16 in pure pancreatic juice obtained by direct cannulation of the pancreatic duct to avoid duodenal secretions may suggest the presence of pancreatic adenocarcinoma

BACKGROUND. It is not rare to find satellite lesions in patients with small hepatocellular carcinoma (HCC). The purpose of this study was to elucidate the factors associated with satellite lesions in these patients. METHODS. We investigated the prevalence of satellite lesions, the relationship of clinicopathologic factors to satellite lesions, and the distance from the main tumor to the satellite lesion in 149 patients. Patients, who had a solitary HCC of 3.0 cm or less in diameter but no satellite lesions on preoperative imaging procedures, underwent potentially curative resection. The main tumors were macroscopically classified into four groups: early HCC, a vaguely nodular type showing preservation of the preexisting liver structure; single nodular type; single nodular type with extranodular growth; and confluent multinodular type. RESULTS. Of 149 resected specimens, 28 (19%) showed satellite lesions. Of the clinicopathologic factors investigated, the macroscopic type and tumor differentiation were significantly associated with the prevalence of satellite lesions. Both the single nodular type with extranodular growth and the confluent multinodular type showed satellite lesions more frequently than the early HCC and the single nodular type. A significantly higher prevalence of satellite lesions was observed in poorly differentiated HCC than in well and moderately differentiated HCC. The satellite lesions were located 0.5 cm or less from the main tumor in 8 (33%) specimens, 0.6-1.0 cm in 12 (50%), and 1.1-2.0 cm in 4 (17%). No identifiable factors were significantly related to the distance from the main tumor to the satellite lesion. However, all satellite lesions located more than 1.0 cm from the main tumor coexisted with poorly differentiated HCC, which were the single nodular type with extranodular growth or the confluent multinodular type. CONCLUSION. In the single nodular type with extranodular growth, confluent multinodular type, and poorly differentiated HCC, extensive treatment achieving a large safety margin and/or frequent posttreatment follow-up examinations may be needed because of the high prevalence of satellite lesions. (C) 2002 American Cancer Society.

While metastasis to the pancreas is uncommon, it may occur from renal cell carcinomas (RCCs). We here present a case of pancreatic metastasis from RCC extending into the main pancreatic duct (MPD) in a 66-year-old Japanese man. The patient had a history of RCC treated with a radical nephrectomy 17 years previously and was found to have a mass similar to2 cm in diameter in the body of the pancreas on radiological images. The patient was suspected of having pancreatic metastasis from RCC and underwent a distal pancreatectomy with splenectomy. Histologically, the tumor consisted of cells arranged in trabecular and alveolar structures with clear or eosinophilic granular cytoplasm, compatible with a metastatic RCC. The pancreatic tumor extended into the MPD with the stream of pancreatic juice. This condition is similar to RCC extension into the renal vein and the inferior vena cava. In conclusion, although extension into the MPD may be rare, such a growth pattern may be characteristic of metastases from RCCs.

Background & Aims: The functional abrogation of several tumor suppressor genes, including p16, DPC4, and p53, is a major mechanism underlying pancreatic ductal carcinogenesis. However, mutational inactivation of these genes is relatively uncommon in intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. We hypothesized that an alternative mechanism for gene inactivation (notably, transcriptional silencing by promoter methylation) could be important in the pathogenesis of IPMNs. Methods: Using methylation-specific polymerase chain reaction, we analyzed the methylation status of 7 CpG islands previously identified as aberrantly methylated in pancreatic adenocarcinoma (including preproenkephalin [ppENK], p16, and thrombospondin 1) in 51 IPMNs of different histologic grades. The relationship between methylation status and expression was evaluated using reverse-transcription polymerase chain reaction for ppENK and immunohistochemistry for p16. Results: We found that more than 80% of the IPMNs exhibited hypermethylation of at least one of these CpG islands. Hypermethylation of ppENK and p16 was detected at a significant higher frequency in high-grade (in situ carcinoma) IPMNs than in low-grade (adenoma/borderline) IPMNs (ppENK, 82% vs. 28%, P = 0.0002; p16, 21% vs. 0%, P = 0.04). Furthermore, the average number of methylated loci was significantly higher in high-grade IPMNs than in low-grade IPMNs (2.4 vs. 0.9; P = 0.0008). Aberrant methylation of ppENK and p16 was associated with loss of expression. Conclusions: These results suggest that de novo methylation of multiple CpG islands is one of the critical pathways that contributes to the malignant progression of IPMNs.

Pancreatic intraductal neoplasia (PanIN) is thought to be the precursor to infiltrating pancreatic ductal adenocarcinoma. We have previously shown that the preproenkephalin (ppENK) and p16 genes are aberrantly methylated in pancreatic adenocarcinoma. In this study we define the methylation status of the ppENK and p16 genes in various grades of PanINs. One hundred seventy-four samples (28 nonneoplastic pancreatic epithelia, 7 reactive epithelia, 29 PanIN-1A, 48 PanIN-1B, 27 PanIN-2, 14 PanIN-3, 15 invasive ductal adenocarcinomas, and 6 miscellaneous pancreatic neoplasms) were microdissected from 29 formalin-fixed paraffin-embedded surgically resected pancreata, and were analyzed by methylation-specific polymerase chain reaction. Fourteen of 15 (93.3%) invasive pancreatic ductal adenocarcinomas showed methylation of the ppENK gene and 4 of 15 (26.7%) showed methylation of the p16 gene. Nonneoplastic pancreatic epithelia did not harbor methylation of either gene. The prevalence of methylation of the ppENK gene increased significantly with increasing PanIN grade. A similar nonsignificant trend was noted for p16 methylation. Aberrant methylation of the ppENK gene was found in 7.7% of PanIN-1A, 7.3% of PanIN-1B, 22.7% of PanIN-2, and 46.2% of PanIN-3. Aberrant methylation of the p16 gene was found in 12% of PanIN-1A, 2.6% of PanIN-1B, 4.5% of PanIN-2, and 21.4% of PanIN-3. All but one of the PanINs from the 14 pancreata without pancreatic carcinoma was unmethylated with respect to either the p16 or ppENK gene. Our results suggest that methylation-related inactivation of the ppENK and p16 genes is an intermediate or late event during pancreatic carcinogenesis. Because aberrant methylation of ppENK or p16 was more often detected in similar grade PanINs from patients with pancreatic carcinoma than in those with other pancreatic diseases, it may be a useful indicator of the potential malignancy of epithelial cells of the pancreas.

The recently identified tumor-suppressor gene TSLC1 on chromosome 11q23.2 is frequently inactivated in human non-small cell lung adenocarcinoma by DNA methylation-associated silencing. The aim of this study was to determine if TSLC1 is inactivated in adenocarcinoma of the pancreas. We analyzed 17 pancreatic cancer cell lines, 91 primary pancreatic adenocarcinoma, 46 pancreatic intraepithelial (PanIN) precursor lesions and 15 microscopically normal pancreata for methylation of the 5' CpG island of the TSLC1 gene through methylation-specific PCR. We observed 5' CpG methylation of TSLC1 in 4 of 17 cell lines (24%). In each cell line the aberrant methylation was associated with loss of TSLC1 expression by RT-PCR that was reversible after treatment with the DNA methyltransferase inhibitor 5-aza-2'- deoxycytidine. Furthermore, we observed that TSLC1 was methylated in 25 of 91 primary pancreatic adenocarcinomas (27%), and in 2 of 7 high-grade PanIN-3 lesions (29%), but not in low-grade PanIN (0 of 9 PanIN-2 and 0 of 30 PanIN-1) lesions or in normal pancreata (n=15). We conclude that epigenetic silencing of TSLC1 expression through 5' CpG island associated methylation is common in pancreatic adenocarcinoma and is a late event in pancreatic neoplastic development.

Primary hepatic lymphoma, mostly diffuse large B-cell lymphoma, is a rare disease. We describe an extremely rare case of low-grade B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type occurring in the liver. A 61-year-old man with a history of hepatitis A presented with early gastric cancer and a liver mass. Needle biopsy of the liver tumor suggested low-grade B-cell lymphoma by histology and polymerase chain reaction of the immunoglobulin heavy chain gene. The tumor (3.4 X 2.8 X 2.4 cm) was completely resected from the anterior segment of the right lobe of the liver. Atypical lymphoid cells of small to intermediate size proliferated in the tumor, and lymphoepithelial lesions were recognized. Immunohistochemically, lymphoma cells were positive for CD20 and negative for CD5, CD10, and cyclin D1. Staging procedures showed no lymphoma lesion other than the liver tumor. Thus, the patient was diagnosed with low-grade hepatic marginal zone B-cell lymphoma of the MALT type. The patient has been followed up for 1.5 years since surgical resection with no recurrence. The clinicopathologic characteristics and management of this rare disease are discussed. Int J Hematol. 2002;75:85-90. (C)2002 The Japanese Society of Hematology.

Mucinous cystic tumors (MCTs) and intraductal papillary-mucinous tumors (IPMTs) are often confused with each other. However, clinicopathological studies have shown that these are two distinct entities. In this review clinicopathological differences and important features for differential diagnosis are presented. MCTs are cyst-forming tumors in the body or tail of the pancreas seen almost exclusively in females. IPMTs show distinct duct ectasia in the pancreatic head with male predominance. Histologically both tumors consist of mucin secreting tall columnar epithelium. MCTs are often accompanied by characteristic "ovarian-type stroma.'' Recent immunohistochemical and gene analysis have not demonstrated significant differences between two tumor types. These tumors should be clearly separated from ordinary ductal adenocarcinomas of the pancreas as they follow indolent course.