Characterisation of the tumour-associated carbohydrate epitope recognised by monoclonal antibody 4D3

Identification of diagnostic upper gastrointestinal cancer tissue type-specific urinary biomarkers

Several potential urinary biomarkers exhibiting an association with upper gastrointestinal tumour growth have been previously identified, of which S100A6, S100A9, rabenosyn-5 and programmed cell death 6-interacting protein (PDCD6IP) were further validated and found to be upregulated in malignant tumours. The cancer cohort from our previous study was subclassified to assess whether distinct molecular markers can be identified for each individual cancer type using a similar approach. Urine samples from patients with cancers of the stomach, oesophagus, oesophagogastric junction or pancreas were analysed by surface-enhanced laser desorption/ionization-time-of-flight mass spectrometry using both CM10 and IMAC30 (Cu²⁺-complexed) chip types and LC-MS/MS-based mass spectrometry after chromatographic enrichment. This was followed by protein identification, pattern matching and validation by western blotting. We found 8 m/z peaks with statistical significance for the four cancer types investigated, of which m/z 2447 and 2577 were identified by pattern matching as fragments of cathepsin-B (CTSB) and cystatin-B (CSTB); both molecules are indicative of pancreatic cancer. Additionally, we observed a potential association of upregulated α-1-antichymotrypsin with pancreatic and gastric cancers, of PDCD6IP, vitelline membrane outer layer protein 1 homolog (VMO1) and triosephosphate isomerase (TPI1) with oesophagogastric junctional cancers, and of complement C4-A, prostatic acid phosphatase, azurocidin and histone-H1 with oesophageal cancer. Furthermore, the potential pancreatic cancer biomarkers CSTB and CTSB were validated independently by western blotting. Therefore, the present study identified two new potential urinary biomarkers that appear to be associated with pancreatic cancer. This may provide a simple, non-invasive screening test for use in the clinical setting.

Relationship between biological behavior and phenotypic expression in undifferentiated-type gastric carcinomas

BACKGROUND

It has been proved that some differentiated-type gastric carcinomas have a gastric phenotype. Similarly, it can be conjectured that some undifferentiated-type gastric carcinomas have an intestinal phenotype and that there are biological differences between undifferentiated-type gastric carcinomas with a gastric phenotype and those with an intestinal phenotype. We classified the phenotypes of early undifferentiated-type gastric carcinomas and investigated the relationship between their biological behavior and the phenotypes.

METHODS

Sixty lesions of intramucosal undifferentiated-type gastric carcinoma were classified into four phenotypes; gastric type, incomplete-intestinal type, complete-intestinal type, and unclassified type, according to the expression of CD10, MUC2, small-intestinal mucinous antigen (SIMA), human gastric mucin (HGM), or concanavalin A (ConA).

RESULTS

The incidence of gastric-type carcinoma, incomplete-intestinal-type carcinoma, and complete-intestinal-type carcinoma was 33% (20 cases), 65% (39 cases), and 2% (1 case), respectively. There was no significant difference in any of the clinicopathological factors examined between the 20 gastric-type carcinomas and the 40 intestinal-type carcinomas, but there were significant differences in the morphological findings. Intestinal-type carcinomas had a glandular structure more frequently than the gastric-type carcinomas. The spreading pattern of gastric-type carcinomas showed a middle-layer type more frequently than the intestinal-type carcinomas.

CONCLUSION

Undifferentiated-type gastric carcinomas frequently expressed an intestinal phenotype. There were differences in the growth patterns between undifferentiated-type gastric carcinomas with a gastric phenotype and those with the intestinal phenotype.

Mucin phenotype and microsatellite instability in early multiple gastric cancers

Clinicopathologically, multiple gastric cancers (MGCs) are reported to involve predominantly intestinal-type adenocarcinoma and frequently to be associated with severe intestinal metaplasia. However, there are few reports concerning the characteristic biomarkers of early MGCs. The aim of our study was to identify the cellular lineage defined by mucin phenotypes and the relationships among mucin phenotypes, background mucosa and microsatellite instability (MSI) of early MGCs. We examined mucin phenotypes of 63 surgically resected carcinomas from 25 patients with early MGCs and 39 early solitary gastric cancers (SGCs) by immunohistochemical analysis using a panel of monoclonal antibodies. MSI and the degree of intestinal metaplasia (IM) on the background mucosa were also examined. In early MGCs, the incidence of cancer exhibiting the gastric phenotype (G-type) was 59% (37 of 63 cancers), which was higher than that in early SGCs (23%, 9 of 39 cancers). There was a significant difference between the distributions of mucin phenotypes in early MGCs and early SGCs (p = 0.001). Whereas half of the G-type cancers in early MGCs were related to severe IM, none of the G-type cancers in early SGCs were related to severe IM. In the early MGCs, MSI was observed in 21 of 63 cancers (33.3%). In contrast, MSI was observed in only 3 of the 39 (7.7%) early SGCs, indicating a significant difference between these 2 groups (p < 0.01). Our results suggest that the characteristic features of early MGCs are the gastric mucin dominant phenotype and high frequency of MSI.

Classification of Barrett's epithelium by magnifying endoscopy

BACKGROUND

The specialized columnar epithelium of Barrett's esophagus can be detected by obtaining random or 4 quadrant biopsy specimens at conventional endoscopy. However, little is known about the fine mucosal structure of specialized columnar epithelium.

METHODS

Thirty patients with Barrett's esophagus were studied by magnifying endoscopy. The fine mucosal pattern (pit pattern) of 67 regions in Barrett's mucosa was recorded and compared with methylene blue staining. Histologic, mucin immunohistologic, and cell proliferation analyses of biopsy specimens were performed in relation to the pit patterns determined by magnifying endoscopy.

RESULTS

Pit pattern was classified into 5 types. Tubular and villous pit patterns were not only characteristics of both specialized columnar epithelium and methylene blue absorption, but also possessed an intestinal mucin phenotype with a high Ki-labeling index, whereas other pit patterns (dot and straight) did not have specialized columnar epithelium and were categorized as the gastric phenotype. The long oval pit pattern had an intermediate phenotype between gastric and intestinal.

CONCLUSIONS

The classification of the superficial mucosal appearance of Barrett's epithelium by magnifying endoscopy reflects not only histologic features but also mucin phenotypes.