Modulation of mucin synthesis by gamma-interferon in human colon adenocarcinoma cells.
OBJECTIVE
Recombinant human interferon has been shown to enhance the expression of histocompatibility antigens and certain tumor-associated antigens in a variety of carcinoma cell lines. Since many tumor-associated antigens are mucins, we investigated the effect of recombinant human gamma-interferon on mucin production and secretion by colon cancer cell lines.


METHODS
Control and gamma-interferon-treated cells were labeled with [(3)H]glucosamine in DMEM-H16 medium with 5% FCS for 24 h. Analysis was performed by gel filtration on Sepharose CL-4B columns, and the high-molecular-weight glycoprotein eluted at the void volume from the cytosol and medium was counted (expressed as dpm/4 x 10(6) cells). In another experiment the void volume was compared to concentration curves of standard mucins (expressed as mg/10(7) cells).


RESULTS
gamma-Interferon increased mucin synthesis in HT-29 and LIM-6 cells, but not in LS174T and CACO2 cells. In HT-29 and LIM-6 cells, mucin synthesis was induced by gamma-interferon in a dose-dependent manner. The percentage of mucin secreted into the medium was also increased.


CONCLUSIONS
The heterogeneity of response of human colon cancer cell lines to gamma-interferon by mucin production may limit the specific role of gamma-interferon as a modulator of mucin-type tumor-associated antigens.
Department of Gastroenterology, Rabin Medical Center, Beilinson Campus, Tel Aviv University, Tel Aviv, Israel. yniv@clalit.org.il
Yaron
Y
Niv
Rivka
R
Koren
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000970:Antineoplastic Agents / Q000494:pharmacology*; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D005944:Glucosamine / Q000032:analysis / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D009077:Mucins / Q000096:biosynthesis*; D011994:Recombinant Proteins; D014407:Tumor Cells, Cultured / Q000187:drug effects
D000970:Antineoplastic Agents; D009077:Mucins; D011994:Recombinant Proteins; D007371:Interferon-gamma; D005944:Glucosamine