Expression of mucin-associated tumor antigens is altered by cell density.

Mucin-associated sialylated Lewis antigens are implicated in tumor cell metastasis and are used in several tests for pancreatic cancer. Despite their clinical importance, little is known about the structures of the oligosaccharides of pancreatic cancer mucins or about the regulation of their synthesis or of the synthesis of their protein cores. In this study, we examined the effects of culture at high cell density on the expression of these antigens in the SW1990 human pancreatic cancer cell line.

Mucins secreted by cell lines derived from colorectal mucinous carcinoma and adenocarcinoma.

Mucinous (colloid) carcinoma and well- to moderately-differentiated adenocarcinoma of the colon differ in the pattern and the amount of mucin secretion and perhaps in their behaviour and clinical outcome. To ascertain why these differences exist and to elucidate the mechanisms of tumour progression, we examined two model human cell lines derived from colorectal mucinous carcinoma (C1a) and moderately differentiated adenocarcinoma (HM3) which show typical pathological and mucin staining patterns of the respective type of carcinomas to nude mouse tumour xenografts. Specifically, we sought to determine if there were quantitative and qualitative differences in mucin synthesis, in mucin gene expression and in biological properties between the two model cell lines.

MUC2 gene expression is found in noninvasive tumors but not in invasive tumors of the pancreas and liver: its close relationship with prognosis of the patients.

We have previously reported that MUC2 apomucin was highly expressed in noninvasive tumors of the pancreas (intraductal papillary tumor [IdPT]) and liver (bile duct cystadenocarcinoma [BdCC]), which show more favorable outcomes than invasive carcinomas. In contrast, MUC2 was rarely expressed in invasive carcinomas of the pancreas (invasive ductal carcinoma [IDC]) and the liver (invasive cholangiocarcinoma [ICC]). In the present study, we examined localization of MUC2 messenger RNA (MUC2 mRNA) by using a complementary DNA (cDNA) probe for the MUC2 tandem repeat for in situ hybridization (pHAM1).

Alteration in mucin gene expression and biological properties of HT29 colon cancer cell subpopulations.

Previous studies from our laboratory have shown that HT29 cells selected by adaptation to methotrexate (HT29-MTX) express mature mucins that differ in their immunoreactivity to antibodies against gastric mucin and in the level of one of two major gastric mucin MUC5AC (MUC5) mRNA compared with parental HT29 cells. In this study, we examined the expression of another major gastric mucin, MUC6 mRNA, as well as that of MUC2, -3 and -5 mRNAs in HT29-MTX cells. We also examined their relationship to mucin-related antigen expression and biological properties of the cells such as adhesion to matrigel and E-selectin and in vitro invasiveness, liver colonising activity and degree of differentiation of nude mouse xenograft.

Association of sialyl-Lewis(a) and sialyl-Lewis(x) with MUC-1 apomucin ina pancreatic cancer cell line.

We have shown previously that the mucins of the human pancreatic cancer cell line, SW1990, have both sialyl-Lewis(a) and sialyl-Lewis(x) carbohydrate ligands that are implicated in tumor cell metastasis. In the present study, we undertook to identify the protein core of these mucins. SW1990 mucins that carry sialyl-Lewis(a) and sialyl-Lewis(x) bound to the MUC1 peptide-specific mAb 139H2.