Related Experiment Video
Updated: Jun 20, 2026
Patient Derived Cell Culture and Isolation of CD133+ Putative Cancer Stem Cells from Melanoma
Published on: March 13, 2013
Improvement of breast cancer cell detection by immunomagnetic enrichment
1Bone Marrow Transplantation Center, University-Hospital Eppendorf, Hamburg, Germany.
Background:
Contaminating breast cancer cells in leukapheresis harvested for reinfusion to rebuild hemopoiesis after high-dose therapy have been described by several investigators. Methods for tumor cell detection are conventional immunocytochemistry, culture techniques and reverse transcriptase PCR. The percentage of tumor cell positive leukaphereses shows a wide variation. An approach to clarify if these cells can induce systemic relapse is to characterize them molecular-genetically and immunologically, but these techniques require a sufficient cell count.
Methods:
We compared conventional immunocytochemistry with immunocytochemistry after immunomagnetic enrichment of cancer cells by HEA-125 magnetic microbeads for the detection of micrometastatic tumor cells. A total of 25 samples, consisting of 16 samples from G-CSF-mobilized peripheral stem cell harvests, eight BM aspirations and one peripheral blood sample were investigated without [median 2, range 1-3 x 10(6) MNCs] and after [median 5, range 1-10 x 10(7) MNCs] HEA-microbead selection. Additionally 10 buffy coat samples from healthy subjects were investigated.
Results:
Using conventional immunocytochemistry, tumor cells could be detected in nine stem cell samples. Two BM samples and the blood sample (48%) were positive, with a median tumor cell load of 0 (0-12) cells per sample (mean: 2.4). By HEA-bead selection the rate of positivity could be increased to 88% (13 stem cell samples, eight marrow samples and one blood sample) with a median load of 6 (0-47) (mean 10.6) suspected cells (p < 0.007). However, calculation of recovery revealed tumor cell losses by immunobead selection. False positive results were not seen.
Discussion:
We conclude first that immunomagnetic selection is an excellent and highly sensitive tool to enrich contaminating cancer cells from marrow and stem cell samples; second that the existence of real tumor cell negative stem cell harvests is doubtful; and third that immunobead selection delivers sufficient tumor cell counts for their further characterization by molecular and immunological methods.
