In vivo molecular imaging of chemokine receptor CXCR4 expression in patients with advanced multiple myeloma.
Bottom Line: We evaluated the novel CXCR4 probe [(68)Ga]Pentixafor for in vivo mapping of CXCR4 expression density in mice xenografted with human CXCR4-positive MM cell lines and patients with advanced MM by means of positron emission tomography (PET). [(68)Ga]Pentixafor PET provided images with excellent specificity and contrast.In 10 of 14 patients with advanced MM [(68)Ga]Pentixafor PET/CT scans revealed MM manifestations, whereas only nine of 14 standard [(18)F]fluorodeoxyglucose PET/CT scans were rated visually positive.Assessment of blood counts and standard CD34(+) flow cytometry did not reveal significant blood count changes associated with tracer application.
Affiliation: III. Medical Department of Hematology and Medical Oncology, Technische Universität München, Munich, Germany.Show MeSH
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Mentions: Considering the high CXCR4 expression levels in a substantial proportion of MM patients as compared to intraindividual control cell populations, we searched for MM cell lines that could be suited for preclinical in vivo imaging studies. Considerable levels of CXCR4 transcript (Fig2A) and protein (Fig2B) were detected in the well-established MM lines MM.1S and OPM-2 as opposed to the ovarian cancer cell line HeLA, which is characterized by low CXCR4 expression. Moreover, MM.1S and OPM-2 cells were found to bind the CXCR4-directed PET probe [68Ga]Pentixafor (Fig2C). Thus, these cell lines represent models for in vivo binding and uptake studies.
Affiliation: III. Medical Department of Hematology and Medical Oncology, Technische Universität München, Munich, Germany.