Disease relevance of MUC3A

• Associations of distinct variants of the intestinal mucin gene MUC3A with ulcerative colitis and Crohn's disease [1].
• Goblet cells expressing the MUC2 gene and columnar cells expressing the MUC3 gene were consistent with an intestinal phenotype, which was observed in 15 tumours (71%) including nine adenomas and six borderline tumours [2].
• Intestinal metaplasia is characterized by an intestinal-type pattern with MUC2 and MUC3 mRNA expression [3].
• MUC2 and MUC3 staining intensity in DCIS was markedly less than that observed for MUC1 [4].
• Among the various mucins expressed in breast cancer, MUC1 and MUC3 are potential prognostic indicators, MUC1 having the strongest relationship with patient outcome [5].

Psychiatry related information on MUC3A

• The expression of mucin genes, MUC 3, 4, 5AC, 5B, 6, 7, and 8 in human fetal tissues was examined to establish the localisation and age of onset of expression of each mucin gene during human development [6].

High impact information on MUC3A

• Endogenous MUC3A in LoVo was inhibited by specific small interfering RNA transfection [7].
• Cysteine-rich domains of muc3 intestinal mucin promote cell migration, inhibit apoptosis, and accelerate wound healing [7].
• METHODS: Both immunocytochemistry and in situ hybridization were used to identify cell types expressing the MUC2 and MUC3 mucins in the human small intestine, colon, and colon carcinoma [8].
• Localization of mucin (MUC2 and MUC3) messenger RNA and peptide expression in human normal intestine and colon cancer [8].
• Consistent with this, in situ hybridization showed MUC2 messenger RNA (mRNA) only in goblet cells and MUC3 mRNA in both goblet and absorptive cells [8].

Chemical compound and disease context of MUC3A

• MUC3 and MCA serum levels and steroid receptor content in breast cancer [9].
• Our results suggest that further investigations are necessary to establish whether progesterone can modulate MUC3 and MCA expression in breast cancer [9].

Biological context of MUC3A

• RESULTS: Expression of MUC3 was detected in the small intestine and colon from 13 weeks gestation onwards and at low levels in the main pancreatic duct at 13 weeks only [6].
• The gene encoding human MUC3 (hMUC3), localised to chromosome 7q22, is most highly expressed in the small intestine [10].
• In contrast, MUC2 and MUC3 gene expression was primarily restricted to the intestinal tract [11].
• Although there was no correlation of mucin expression with tumor histology, there was a significant decrease in expression of MUC3 and MUC4 with increasing cancer stage (P < 0.05) [12].
• The region of MUC3 located upstream of the previously described 51-base pair (bp) tandem repeats, which encode a major Ser and Thr-rich domain, consists of a second type of repetitive structure with an imperfect periodicity of approximately 1125 bp [13].

Anatomical context of MUC3A

• MUC3B, like MUC3A, is expressed in intestine and Caco-2 cells [14].
• Surprisingly, MUC3, which was the gene which was most expressed in the biliary tree, was also found in hepatocytes, suggesting another function for the MUC3 protein than that of a secreted mucin [15].
• Interestingly, normal gastric cardia mucosa also showed a significantly higher prevalence of MUC2 and MUC3 expression in glandular epithelium (29% and 38%, respectively) compared with the antrum (0% for both markers) (P < 0.05) [16].
• Surprisingly, MUC3 which is strongly expressed in adult pancreas, was not detected in developmental pancreas [17].
• RESULTS: The findings showed mRNA expression of MUC3, MUC5B and MUC6 in most gallbladders in all three groups, but stronger and extensive expression of these mRNAs in gallbladders with stones [18].

Associations of MUC3A with chemical compounds

• These results were consistent with immunoblots using anti-MRP (MUC2 repeat peptide), anti-M3P (MUC3 repeat peptide), 139H2 (MUC1 peptide), anti-T (peanut lectin), anti-Tn (91S8), and anti-sialosyl Tn (JT10e) antibodies [19].
• MUC3 is a large mucin glycoprotein expressed by the human intestine and gall bladder [13].
• The MUC3 carboxyl-terminal domain is 617 residues in length, including 511 residues of a non-repetitive mucin-like domain (27% Thr, 22% Ser, and 11% Pro) and a 106-residue Cys-rich domain with homology to the epidermal growth factor (EGF) -like structural motifs found in many proteins [13].
• MUC6 and MUC3 were constitutively expressed, and steroid-induced, in BT-474 and MCF-7 cells, respectively [20].
• The MUC3 precursor was completely degraded by trypsin, but the MUC2 precursor had a trypsin-resistant fragment of M(r) approx. 240,000 containing threonine and cysteine [21].

Other interactions of MUC3A

• MUC3 and MUC6 were constantly and focally expressed, respectively, in the biliary epithelial cells in the intrahepatic large bile ducts in normal livers, extrahepatic biliary obstruction, and, also, hepatolithiasis [22].
• These data suggest that the biliary epithelial cells switch MUC1 apomucin expression before birth to that of MUC3 after birth [23].

Analytical, diagnostic and therapeutic context of MUC3A

• RNase protection analysis and 5'-GeneRacer PCR indicated that MUC3A gene transcripts initiate from multiple start sites along a region spanning approximately 180 bases [24].
• Addition of bile during either storage in UW solution or rewarming period induced increased steady-state MUC2, MUC3 and MUC5AC mRNA levels.(ABSTRACT TRUNCATED AT 250 WORDS)[25]
• RT-PCR was performed to investigate the carboxyl terminus of the published sequence of hMUC3 from normal colon and small intestine tissues and also from a series of 10 colorectal cancer cell lines [10].
• Both MUC2 and MUC3 proteins, identified by labelling with [3H]threonine or [35S]cysteine and immunoprecipitation with antibodies to synthetic mucin peptides, were already of large size (M(r) > 180,000) by the earliest labelling time (5 min) [21].
• Northern blot analysis showed that MUC2 mRNA levels were significantly higher in C1a cells compared with HM3 cells, while those of MUC3, -5 and -6 mRNA were lower [26].

References