Specific secretion of gel-forming mucins and TFF peptides in HT-29 cells of mucin-secreting phenotype

Abstract

Trefoil factor family (TFF) peptides are typical secretory products of mucin-producing cells, e.g. of the gastrointestinal tract. Here, the expression and secretion of mucins and TFF peptides was studied in the HT-29 cell line throughout cellular growth and differentiation in relation to a mucin-secreting (HT-29 MTX) or an enterocyte-like (HT-29 G(-)) phenotype. mRNAs of several MUC and TFF genes were expressed in both cell subpopulations. However, for most MUC and TFF genes, the expression appeared strongly induced with the differentiation into the mucin-secreting phenotype. On the other hand, TFF2 was specifically expressed in the mucin-secreting HT-29 MTX cells. The differentiation of HT-29 MTX cells into the mucin-secreting phenotype was characterised by secretion of the gel-forming mucins MUC2, MUC5AC, and MUC5B, however, according to a different pattern in the course of differentiation. A significant amount of TFF1 and TFF3 was secreted after differentiation, also according to a different pattern, whereas TFF2 was only faintly detected. Secretagogues, known to induce the secretion of mucus, increased the secretion of all three TFF peptides. In contrast, neither a secretory mucin nor a TFF peptide was found in the culture medium of HT-29 G(-) cells. Overlay assays indicated that HT-29 MTX mucins bound to secretory peptides of HT-29 MTX cells with relative molecular mass similar to TFF peptides. TFF1 and TFF3 were specifically localised in the mucus layer of HT-29 MTX cells by confocal microscopy. Finally, the secretion of TFF peptides and mucins appears as a co-ordinated process which only occurs after differentiation into goblet cell-like phenotype.

GATA-4 and GATA-5 Transcription Factor Genes and Potential Downstream Antitumor Target Genes Are Epigenetically Silenced in Colorectal and Gastric Cancer

“…7C and Table 1) of inhibin␣ and TFF1 in all cell lines in which these genes are basally silent. When examined at the protein level, the GATA-5 overexpression resulted in expression of the secreted TFF1 protein (15) in the media of the cell cultures (Fig. 7D).…”

Characterization of Gene Expression Profiles in Intraductal Papillary-Mucinous Tumors of the Pancreas

“…This difference between TFF2 RNA and protein expression has been previously reported and could potentially be explained by impaired accessibility of the epitope or a defect of translation. 30 Galectin 3 is a member of the ␤-galactosidase-binding lectin family. 31 It is involved in diverse physiological and pathological processes, including the regulation of cell growth, cell differentiation and inflammatory responses.…”

Expression of D-type cyclins in colon cancer and in cell lines from colon carcinomas

“…Differentiation was induced by NaB, which is a well-known differentiation inducer of colonic epithelial cells (Kim et al, 1980). It has been demonstrated that NaB induces differentiation of colon-derived cell lines into mucus-secreting goblet cells that produce mucin glycoproteins and into absorptive enterocytes, which are characterised by elevated ALP activity (Wice et al, 1985;Schroy et al, 1994;Velcich et al, 1995;Gouyer et al, 2001). Induction of differentiation was followed by measurement of ALP activity in cell lysates (Colony and Neutra, 1983) and by RT -PCR detection of mRNA levels of two differentiation markers, CEA (Huitric et al, 1976;Velcich et al, 1995) and mucin 3 (MUC3) (Velcich et al, 1995;Gouyer et al, 2001;Gaudier et al, 2004).…”