The K-ras, p53, p16 and DPC4 genes are among those most frequently altered in pancreatic ductal carcinoma. We analyzed 22 cell lines for alterations in these genes by direct sequence analysis and methylation-specific polymerase chain reaction. These cell lines showed mutations in K-ras and p53 at frequencies of 91% and 95%, respectively. Alterations in p16INK4a were found in all cases and included nine homozygous deletions, seven mutations and promoter methylation in six cases. Eight cell lines (36%) had an alteration of DPC4, including one mutation and seven homozygous deletions. The most typical mutational profile involved K-ras, p53, and p16INK4a, concurrently aberrated in 20 cases (91%). Eight cell lines had alterations in all four genes. Inactivation of DPC4 was always accompanied by alteration of all of the other three genes. This comprehensive data regarding the cumulative genetic alterations in pancreatic carcinoma cell lines will be of great value for studies involving drug sensitivity or resistance that may be associated with inactivation of a particular gene or molecular pathway.

Summary Alterations of K-ras, p53, p16 and DPC4/Smad4 characterize pancreatic ductal cancer (PDC). Reports of inactivation of these latter two genes in pancreatic endocrine tumours (PET) suggest that common molecular pathways are involved in the tumorigenesis of pancreatic exocrine and endocrine epithelia. We characterized 112 primary pancreatic tumours for alterations in p16 and DPC4 and immunohistochemical expression of DPC4. The cases included 34 PDC, 10 intraductal papillary-mucinous tumours (IPMT), 6 acinar carcinomas (PAC), 5 solid-pseudopapillary tumours (SPT), 16 ampulla of Vater cancers (AVC) and 41 PET. All tumours were also presently or previously analysed for K-ras and p53 mutations and allelic loss at 9p, 17p and 18q. Alterations in K-ras, p53, p16 and DPC4 were found in 82%, 53%, 38% and 9% of PDC, respectively and in 47%, 60%, 25% and 6% of AVC. Alterations in these genes were virtually absent in PET, PAC or SPT, while in IPMT only K-ras mutations were present (30%). Positive immunostaining confirmed the absence of DPC4 alterations in all IPMT, SPT, PAC and PET, while 47% of PDC and 38% of AVC were immunonegative. These data suggest that pancreatic exocrine and endocrine tumourigenesis involves different genetic targets and that among exocrine pancreatic neoplasms, only ductal and ampullary cancers share common molecular events.

Summary Whether duodenal adenocarcinoma should be considered as a gastrointestinal or as a peripancreatic cancer is a matter of debate, as is the opportunity and type of treatment. We investigated 12 such cancers for the genetic anomalies involved in the pathogenesis of gastrointestinal malignancies, including (a) those occurring in common-type cancers -allelic losses at chromosomes 3p, 5q, 1 7p and 1 8q, and Ki-ras and p53 alterations; and (b) those characteristic of mutator-phenotype cancers -microsatellite instability and TGF-PRII gene mutations. We found Ki-ras and p53 mutations in five (42%) and eight cancers (67%), respectively; chromosome 3p, 5q, 1 7p and 1 8q allelic losses in two of nine (22%), six of ten (60%), six of nine (67%) and three of ten (30%) informative cancers, respectively. Finally, three cancers (25%) showed widespread microsatellite instability and two of them had a TGF-pRII gene mutation. Our data suggest that duodenal cancers may arise from either of the two known pathogenetic molecular pathways of gastric and colorectal cancers. The majority of our cases were highly aggressive cancers with frequent chromosomal changes and p53 mutations as observed in the common-type gastrointestinal malignancies, while widespread subtle alterations characteristic of mutator-phenotype cancers occurred in a minority, which also showed a favourable long-term outcome.

Summary During our studies of DNA fingerprinting of tumours of the pancreas and papilla (ampulla) of Vater, using arbitrarily primed polymerase chain reaction (AP-PCR), we noticed two bands showing a decreased intensity in six of ten ampullary tumours with respect to matched normal tissues. Those bands were both assigned to chromosome 5. Such a finding was somewhat in contrast with the reportedly low frequency of APC gene mutations in ampullary cancers, located at chromosome 5q21, and suggested that loci different from that of APC might be the target of chromosome 5 allelic losses (LOH) in these tumours. Therefore, we analysed chromosome 5 LOH in a panel of 27 ampullary tumours, including eight adenomas, four earty-and 15 advanced-stage cancers, using 16 PCR-amplified CA microsatellite polymorphic markers spanning the entire chromosome. Nineteen cases (70%/a) showed LOH, and the interstital deletions found in these tumours described two smallest common deleted regions, in which putative suppressor genes might reside. They were at 5q13.3-q14 and at 5q23-q31 respectively, which correspond to those found in gastic tumours. In additon, the presence of 5q LOH in six of eight adenomas and in three of four earty-stage cancers suggests that such phenomena occur at earty stages of neoplastic progression of the ampullary epithelium.

Immunohistochemistry of normal eccrine sweat glands was performed on paraffin sections of human skin. Immunoreactivity (ir) for neuron specific enolase, S100 protein (S100), regulatory peptides, nitric oxide synthase type I (NOS-I) and choline-acetyltransferase (ChAT) was found in small nerve bundles close to sweat glands. In the glands, secretory cells were labelled with anticytokeratin antibody. Using antibodies to S100, calcitonin gene-related peptide (CGRP) and substance P (SP) a specific distribution pattern was found in secretory cells. Granulated (dark) and parietal (clear) cells were immunopositive for CGRP, and S100 and SP, respectively. Immunoreactivity was diffuse in the cytoplasm for CGRP and S100, and peripheral for SP. Myoepithelial cells were not labelled. Electron microscopy revealed electron dense granules, probably containing peptide, in granulated cells. Using antibodies to NOS-I and ChAT, ir was exclusively found in myoepithelial cells. Immunoreactivity for the atrial natriuretic peptide was absent in sweat glands. These results provide evidence for the presence of both regulatory peptides involved in vasodilation and key enzymes for the synthesis of nitric oxide and acetylcholine in the secretory coil of human sweat glands. It is suggested that human sweat glands are capable of some intrinsic regulation in addition to that carried out by their nerve supply.Key words : Neuropeptides ; nitric oxide synthase ; choline-acetyltransferase ; substance P ; calcitonin gene-related peptide. Eccrine sweat glands are widespread in human skin and represent a major source of evaporative heat loss from the body. They consist of a secretory coil located deep in the reticular layer of the dermis or in the hypodermis and a duct reaching the skin surface. Three cell types are consistently described in the secretory coil of eccrine sweat glands namely, the ' clear ', ' dark ', and myoepithelial cells (Ellis, 1967 ; Breathnach, 1971). These cell types have been associated with water and ion secretion, production of sweat proteins, and the mechanism of sweat transfer to the excretory duct, respectively (Kurosumi et al. 1984 ;Sato et al. 1989). Typically, myoepithelial cells are placed in a basal position in the epithelium, possess a few, long cell processes running on the basal lamina, and they do not reach the lumen. In contrast,Correspondence to Dr Carlo Zancanaro, Istituto di Anatomia Umana ed Istologia, Strada Le Grazie, 8, I-37134 Verona, Italy. Tel. : j39-45-8098155 ; fax j39-45-8098163 ; e-mail : Carloz!borgoroma.univr.it both clear and dark cells contact the lumen. Preliminary light and electron microscopic investigations on human sweat glands showed that most clear cells are flask-shaped and are placed in a parietal position in the secretory epithelium ; their contact with the lumen is mainly by means of intra and intercellular secretory canaliculi provided with short microvilli. Dark cells consistently show extensive, direct contact with the lumen and thin basal processes. On the ba...

Recent data suggest that SEL1L may play an important role in pancreatic carcinoma, similar to breast cancer, where the expression of SEL1L has been associated with a reduction in both proliferative activity in vitro and clinical tumor aggressiveness. To investigate this possibility, we examined the expression of Sel1L in a series of primary pancreatic carcinomas by immunohistochemistry and characterized the effects of Sel1L overexpression both in vitro and in vivo. In 74 pancreatic cancers analysed, 36% lacked Sel1L expression, although there was no significant correlation between the expression of Sel1L and any clinicopathologic parameter, including survival. However, immunohistochemical reactivity for Sel1L and Dpc4/ Smad4 was concordant in 69% of cases (v 2 test Po0.004). Overexpression of SEL1L in stably transfected pancreatic cancer cells caused both a decrease in clonogenicity and anchorage-independent growth as well as a significant increase in the levels of activin A and SMAD4. When implanted in nude mice, Suit-2-SEL1L-overexpressing clones displayed a considerably reduced rate of tumor growth. Thus, it can be hypothesized that Sel1L plays an important function in the growth and aggressiveness of pancreatic carcinoma. Moreover, our data provide evidence that SEL1L has an impact on the expression of genes involved in regulation of cellular growth, possibly through the TGF-b signaling pathway.

We explored APC gene mutations and chromosome 5q21 allelic losses (5qLOH) in 18 neoplasms of the papilla of Vater, including 6 early-stage tumours (3 adenomas, 3 carcinomas) and I 2 advanced-stage cancers. Eleven PCR-amplified polymorphic sequences were used to analyse 5qLOH. AfK mutations were investigated both by an In vitro APC-protein truncation test and by single-strand conformation polymorphism analysis. Mutations in the Ki-ras, N-ras and p53 genes were also assessed. We found: 5qLOH in 8 of 16 cases (50%), including I adenoma. 3 early-and 4 advanced-stage cancers; APC mutations in 2 adenomas and I advanced-stage carcinoma; Ki-or N-ras mutations in 3 adenomas and 3 advanced-stage cancers; pS3 mutations in 2 early-stage and 7 advanced-stage adenocarcinomas. Our results suggest that SqLOH, APC mutations and ras mutations are present at early stages, whereas p53 inactivation is associated with progression of malignancy in a large proportion of cases. These data indicate that sporadic ampullary tumours differ from those occurring in familial adenomatous polyposis in the frequency (I 7% vs. 64Oh) as well as in the site of APC somatic mutations, suggesting a different molecular pathogenesis in the 2 conditions. cri 1906 Wilq-Liss, Inc.Ampullary epithelial neoplasms include benign (5%) and malignant tumours (95%) centered in the region of the papilla of Vater. They represent 5% of all sporadic gastrointestinal tumours, but account for up to 36% of the surgically operable pancreatoduodenal tumours, whereas sporadic duodenal neoplasms not originating from ampullary structures arc exccedingly rare. Ampullary and duodenal non-ampullary neoplasms occur at a high frequency in patients affected by familial adenomatous polyposis (FAP) (reviewed in Gallinger et a/.,

In order to assess the suitability of cryopreserved neoplastic tissues for xenografting into nude (nu/nu) mice, we compared the take rate in 28 samples of pancreatic ductal carcinoma. Eleven fresh samples were implanted in nu/nu mice, and 17 were frozen in cryopreserving solution and implanted at a later time. All samples were examined for the presence of neoplastic tissue in cryostat sections. A total of 15 tumors grew in the animals; five from the freshly implanted samples and ten from those cryopreserved. Ten xenografted tumors were characterized for alterations in p53, K-ras, and p16 genes, which were found in six, eight, and nine cases, respectively. Our results demonstrate that the take rate for xenografting is comparable between cryopreserved and fresh tissue samples. The procedure allows for the exchange of tumor material between institutions and permits the establishment of centralized facilities for the storage of an array of different primary tumor samples suitable for the production of in vivo models of cancers.