title: Differential mucin expression in colon carcinoma HT-29 clones with variable resistance to 5-fluorouracil and methotrexate.
abstract: A current challenge is to define the biological characteristics of colon tumor cells resistant to chemotherapy. Distinct sub-populations of mucus-secreting cells were previously obtained from the colon cancer cell line HT-29 after long-term treatment with the anti-cancer drugs, 5-fluorouracil (5-FU) and methotrexate (MTX). Since mucins are increasingly implicated as playing a role in carcinogenesis, we studied the pattern of mucin expression in two HT-29 clones of mucus-secreting and two clones of enterocyte-like phenotype which differ in their capacity to resist to 5-FU and/or MTX. The expression of both transmembrane (MUC1, MUC3, MUC4) and secreted gel-forming (MUC2, MUC5AC, MUC5B, MUC6) mucins in clones was studied by northern and/or western blotting. The four HT-29 clones showed three cellular phenotypes: (1) The mucus-secreting clone HT29-5F12 consists of unpolarized cells with mucus secretions that have anti-colonic mucin immunoreactivity, and mainly expresses MUC2 and is resistant to 5-FU and sensitive to MTX; (2) The mucus-secreting clone HT29-5M21 forms a monolayer of polarized cells with strong anti-gastric mucin immunoreactivity and mainly expresses MUC5AC and MUC5B and is resistant to MTX and sensitive to 5-FU; (3) The two enterocyte-like clones, HT29-5F7 and HT29-5M12 are resistant to both MTX and 5-FU and express mainly MUC1 and MUC5B, respectively. These clones which originate from a same colorectal tumour and display different patterns of mucin expression as well as differing resistance to MTX and 5-FU will make useful in vitro models for studying the potential role of mucins or other biological markers in drug resistance pathways.
authors.affiliation: INSERM U560, Place de Verdun, 59045 Lille cedex, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Leteurtre
authors.forename: Valérie
authors.initials: V
authors.lastname: Gouyer
authors.forename: Karine
authors.initials: K
authors.lastname: Rousseau
authors.forename: Odile
authors.initials: O
authors.lastname: Moreau
authors.forename: Alain
authors.initials: A
authors.lastname: Barbat
authors.forename: Dallas
authors.initials: D
authors.lastname: Swallow
authors.forename: Guillemette
authors.initials: G
authors.lastname: Huet
authors.forename: Thécla
authors.initials: T
authors.lastname: Lesuffleur
mesh_terms: D015152:Blotting, Northern; D015153:Blotting, Western; D002999:Clone Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005472:Fluorouracil / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic; D019073:HT29 Cells; D006801:Humans; D008727:Methotrexate / Q000494:pharmacology*; D008854:Microscopy, Electron; D009077:Mucins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D009077:Mucins; D012333:RNA, Messenger; D005472:Fluorouracil; D008727:Methotrexate