Tumor Cell Purging by Ex Vivo Expansion of Hemopoietic Stem Cells from Breast Cancer Patients Combined with Targeting ErbB Receptors

Abstract

Tumor cell contamination might induce relapse after autologous transplantation in breast cancer patients. We used an ex vivo purging strategy to decrease the number of contaminating breast tumor cells in leukaphereses without altering the engraftment potential of the hemopoietic progenitor cells. This method is based on immunoselection of CD34+ cells derived from mobilized peripheral blood of patients with metastatic breast cancer and expansion in the presence of flt3 ligand, stem cell factor, interleukin 6, and thrombopoietin. Tumor contamination before and after culture was monitored by mammaglobin messenger RNA amplification by quantitative polymerase chain reaction. We analyzed both adherent and suspended cells obtained after 2 weeks of culture. Hemopoietic progenitors were increased among suspended cells. In this fraction, tumor cell contamination was decreased, whereas it increased within the adherent cell fraction. Experimental models using CD34+ cells from healthy donors spiked with breast cancer cells were also constructed to investigate whether treatment with anti-ErbB-receptor drugs could further reduce the tumor load without affecting the clonogenic potential of hemopoietic cells. For this purpose, we successfully assayed trastuzumab, a monoclonal antibody against ErbB-2, and gefitinib, an epidermal growth factor receptor tyrosine kinase receptor inhibitor. These results suggest that positively selected CD34+ cells from cancer patients contain tumor cells and that ex vivo expansion can reduce the tumor load of the suspended fraction. Target-based agents against ErbB-2, epidermal growth factor receptor, or both--such as trastuzumab or gefitinib--might increase the efficiency of purging.

Unraveling Graft-versus-Host Disease and Graft-versus-Leukemia Responses Using TCR Vβ Spectratype Analysis in a Murine Bone Marrow Transplantation Model

“…However, in the case of a known tumor antigen, it is also possible to presensitize a normal donor, as described by Kwak et al and others (44, 45). In addition, tumor cell purging of ex vivo expanded hematopoietic stem cells has been successfully implemented in autologous transplant for both liquid and solid tumors (46, 47). …”

The Incidence of Tumor Cell Contamination of Peripheral Blood Stem Cells: A Meta-Analysis to Evaluate the Impact of Mobilization Regimens and the Influence on Outcomes in Breast Cancer Patients

“…Only 6 out of 17 studies reported the ER/PR/HER2 status of the breast tumor in patients [6,9,20,23,28,36]. Six studies utilized the CO regimen [20,25,26,27,28,36], 4 studies used the C+C regimen [8,10,24,33], and 7 studies compared both CO and C+C regimens [6,9,22,23,29,35,37]. Eleven studies used immunocytochemistry of cytokeratin [5,8,10,20,22,25,26,27,35,36,37].…”

“…The studies were published between 1995 and 2006 and are summarized in table 1. Most of the studies included stage IV breast cancer patients [5,6,9,10,20,22,23,24,25,26,27,28,29,30,31,32,33,34]; however, some studies also included high-risk stage II and III patients [5,22,25,26,27,29,32,34,35,36,37]. The percentage of patients evaluated with stage II/III and stage IV disease was not significantly different in the CO versus C+C groups (data not shown).…”

“…Other methods included immune cytochemistry of other markers (alkaline phosphatase, MUC1, MAS-385, SB-3, SB-6, CD-11, TFS-2) and RT-PCR (carcinoembryonic antigen or mammaglobin) for detection of TCC in PBSCs. Fifteen out of 17 studies investigated only G-CSF as a cytokine, whether given alone or in combination with chemotherapy [5,6,8,20,22,23,24,25,26,27,28,29,35,36,37,38]. Five studies reported RR after PBSC transplantation in patients with tumor cell-positive versus tumor cell-negative PBSCs [6,8,28,36,37], whereas PFS and OS data were recorded for 4 studies [9,10,20,23].…”