title: Detection of bone marrow-disseminated breast cancer cells using an RT-PCR assay of MUC5B mRNA.
abstract: The evaluation of disseminated epithelial tumor cells in breast cancer patients has generated considerable interest due to its potential association with disease recurrence. Our work was performed to analyze the usefulness of 5 mucin genes expression (MUC2, MUC3, MUC5B, MUC6 and MUC7), using RT-PCR assays, to detect disseminated cancer cells in patients with operable breast cancer. The highest frequencies of positive RT-PCR tests in breast tumor extracts were observed for MUC5B (7/15) and MUC7 (5/12). The best specificity, negative results on all peripheral blood mononuclear (PBMN) cell samples from healthy donors, were shown for MUC2, MUC5B and MUC6 RT-PCR assays. Thus, we selected MUC5B as a target gene for further evaluation. Using a nested RT-PCR, MUC5B mRNA transcripts were detected in 16/31 primary breast tumors (but not in 36 samples of normal PBMN cells) and in the human MCF-7 breast cancer cell line but not in BT20, MDA, T47D and ZR-75 breast cancer cell lines, indicating that MUC5B mRNA is expressed in a population of breast cancer cells. Using this method, 9/46 patients (19.5%) who underwent curative surgery showed positive MUC5B mRNA in bone marrow aspirates obtained prior to surgery, including 5/24 patients (20.8%) with stage I or II breast cancer, without histopathologic lymph node involvement. These results indicate that MUC5B mRNA could be a specific marker applicable to the molecular diagnosis of breast cancer cell dissemination. A comparative evaluation between MUC5B mRNA, cytokeratin 19 (CK19) mRNA and carcinoembryonic antigen (CEA) mRNA in all bone marrow aspirates suggests a putative complementation for molecular detection of disseminated carcinoma cells. Considering that breast cancer is characterized by a great phenotypic heterogeneity, the use of multimarker approach could contribute to tumor cell detection in bone marrow and blood.
authors.affiliation: Laboratorio de Oncología Básica y Biología Molecular, Depto. de Bioquímica, Facultad de Medicina, Av. Gral. Flores 2125, Montevideo CP 11800, Uruguay. nberois@fmed.edu.uy
authors.forename: Nora
authors.initials: N
authors.lastname: Berois
authors.forename: Mario
authors.initials: M
authors.lastname: Varangot
authors.forename: Cecilia
authors.initials: C
authors.lastname: Sóñora
authors.forename: Leticia
authors.initials: L
authors.lastname: Zarantonelli
authors.forename: Carlos
authors.initials: C
authors.lastname: Pressa
authors.forename: Raúl
authors.initials: R
authors.lastname: Laviña
authors.forename: José Luis
authors.initials: JL
authors.lastname: Rodríguez
authors.forename: Fernando
authors.initials: F
authors.lastname: Delgado
authors.forename: Nicole
authors.initials: N
authors.lastname: Porchet
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Aubert
authors.forename: Eduardo
authors.initials: E
authors.lastname: Osinaga
mesh_terms: D001853:Bone Marrow / Q000378:metabolism*; D001854:Bone Marrow Cells; D001943:Breast Neoplasms / Q000378:metabolism*; D017931:DNA Primers / Q000494:pharmacology; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D055257:Mucin-5B; D009077:Mucins / Q000096:biosynthesis* / Q000378:metabolism; D009362:Neoplasm Metastasis; D012333:RNA, Messenger / Q000378:metabolism*; D012008:Recurrence; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
chemical_list: D017931:DNA Primers; C524578:MUC5B protein, human; D055257:Mucin-5B; D009077:Mucins; D012333:RNA, Messenger