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Purpose: The CD133 antigen has been identified as a putative stem cell marker in normal and malignant brain tissues. In gliomas, it is used to enrich a subpopulation of highly tumorigenic cancer cells. According to the cancer stem cell hypothesis, CD133-positive cells determine long-term tumor growth and, therefore, are suspected to influence clinical outcome. To date, a correlation between CD133 expression in primary tumor tissues and patients' prognosis has not been reported., Experimental Design: To address this question, we analyzed the expression of the CD133 stem cell antigen in a series of 95 gliomas of various grade and histology by immunohistochemistry on cryostat sections. Staining data were correlated with patient outcome., Results: By multivariate survival analysis, we found that both the proportion of CD133-positive cells and their topological organization in clusters were significant (P < 0.001) prognostic factors for adverse progression-free survival and overall survival independent of tumor grade, extent of resection, or patient age. Furthermore, proportion of CD133-positive cells was an independent risk factor for tumor regrowth and time to malignant progression in WHO grade 2 and 3 tumors., Conclusions: These findings constitute the first conclusive evidence that CD133 stem cell antigen expression correlates with patient survival in gliomas, lending support to the current cancer stem cell hypothesis.

Objective Analysis of the efficiency and toxicity of cyclophosphamide-based stem cell mobilization in patients with relapsed multiple myeloma ( RMM). Methods Peripheral blood stem cells ( PBSCs) were mobilized with high dose cyclophosphamide (2 g/m2 daily on days 1 and 2) and G- CSF plus pre-emptive/rescue plerixafor in RMM patients (first to third relapse) treated within the Re LApsE trial of the German-Speaking Myeloma Multicenter Group ( GMMG). Results Mobilization was initiated with high-dose cyclophosphamide (HD-CY) and G- CSF in 30 patients. Fifteen patients received additional pre-emptive/rescue administration of plerixafor. Stem cell collection was successful (≥2×106 CD34+ cells per kg bw) in 77% (23/30 patients). Patients with prior high-dose melphalan collected a significantly lower median total number of PBSCs than patients without prior high-dose melphalan (3.3×106 vs 17×106 CD34+ cells/kg bw). Toxicity of HD-CY was frequent with 12 serious adverse events ( SAE) in 37% of patients (11/30 patients). Infections accounted for the majority of SAE reports. In two patients, SAEs were lethal (septic shock). Conclusions These data proof feasibility of PBSC collection at relapse but emphasize the importance of collection and storage of additional PBSC transplants during first-line treatment when mobilization is more efficient and less toxic. [ABSTRACT FROM AUTHOR]

To study the clinical relevance of undifferentiated tumour cells in astrocytic gliomas we employed a large tumour tissue microarray (n == 283) with corresponding clinical data and analyzed the expression of Nestin and Sox-2, which mark undifferentiated stem- and progenitor cells in the normal brain. Both markers were expressed abundantly and staining of nestin significantly increased with WHO grade. Further, nestin and Sox-2 immunoreactivity was significantly associated with tumour cell proliferation and nestin expression was independently associated with poor patient survival. Our findings suggest that immature glioma cells are involved in tumour growth and tumour progression and significantly impact on patient prognosis. [ABSTRACT FROM AUTHOR]