title: ErbB2 and bone sialoprotein as markers for metastatic osteosarcoma cells.
abstract: Osteosarcoma is the most common malignant bone neoplasia occurring in young patients in the first two decades of life, and represents 20% of all primitive malignant bone tumours. At present, treatment of metastatic osteosarcoma is unsatisfactory. High-dose chemotherapy followed by CD34+ leukapheresis rescue may improve these poor results. Neoplastic cells contaminating the apheresis may, however, contribute to relapse. To identify markers suitable for detecting osteosarcoma cells in aphereses we analysed the expression of bone-specific genes (Bone Sialoprotein (BSP) and Osteocalcin) and oncogenes (Met and ErbB2) in 22 patients with metastatic osteosarcoma and six healthy stem cell donors. The expression of these genes in aphereses of patients affected by metastatic osteosarcoma was assessed by RT-PCR and Southern blot analysis. Met and Osteocalcin proved to be not useful markers since they are positive in aphereses of both patients with metastatic osteosarcoma and healthy stem cell donors. On the contrary, BSP was expressed at significant levels in 85% of patients. Moreover, 18% of patients showed a strong and significantly positive (seven to 16 times higher than healthy stem cell donors) ErbB2 expression. In all positive cases, neoplastic tissue also expressed ErbB2. Our data show that ErbB2 can be a useful marker for tumour contamination in aphereses of patients affected by ErbB2-expressing osteosarcomas and that analysis of Bone Sialoprotein expression can be an alternative useful marker.
authors.affiliation: Institute for Cancer Research and Treatment (IRCC), University of Torino Medical School, Candiolo, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Valabrega
authors.forename: F
authors.initials: F
authors.lastname: Fagioli
authors.forename: S
authors.initials: S
authors.lastname: Corso
authors.forename: E
authors.initials: E
authors.lastname: Madon
authors.forename: A
authors.initials: A
authors.lastname: Brach del Prever
authors.forename: E
authors.initials: E
authors.lastname: Biasin
authors.forename: A
authors.initials: A
authors.lastname: Linari
authors.forename: M
authors.initials: M
authors.lastname: Aglietta
authors.forename: S
authors.initials: S
authors.lastname: Giordano
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001859:Bone Neoplasms / Q000378:metabolism / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D058574:Integrin-Binding Sialoprotein; D008297:Male; D009362:Neoplasm Metastasis; D015675:Osteocalcin / Q000378:metabolism; D012516:Osteosarcoma / Q000378:metabolism / Q000556:secondary*; D011518:Proto-Oncogene Proteins; D019859:Proto-Oncogene Proteins c-met; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D017978:Receptors, Growth Factor; D012795:Sialoglycoproteins / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D058574:Integrin-Binding Sialoprotein; D015675:Osteocalcin; D011518:Proto-Oncogene Proteins; D019859:Proto-Oncogene Proteins c-met; D018719:Erb-b2 Receptor Tyrosine Kinases; D017978:Receptors, Growth Factor; D012795:Sialoglycoproteins; D015534:Trans-Activators; C546871:IBSP protein, human; C491743:MET protein, human