Fig. 3: Agnospheres generate phenocopies of the original tumors and contain a high percentage of tumor-initiating cells.
a Histopathological features (hematoxylin and eosin staining, H&E) and immunohistochemistry with antibodies used for CUP diagnosis, in patient metastases (left columns), tumors formed by agnospheres at the subcutaneous injection site (middle columns), and cultured agnospheres (right columns). Scale bar, 50 μm. A representative experiment is shown (n = 3 independent stainings of agnospheres with similar results were obtained). b Immunofluorescent stainings of stem cell markers in patient metastases (left columns) and tumors formed by the corresponding agnospheres at the subcutaneous injection site (right columns). Nuclei were counterstained with DAPI. Scale bar, 50 μm. A representative experiment is shown (n = 3 independent stainings of agnospheres with similar results were obtained). c In vivo limiting dilution assay. The indicated numbers of agnosphere cells (105–101) were transplanted subcutis into immunocompromised mice (P0) and, where indicated, agnospheres were re-derived in culture and transplanted for a second (P1) or a third (P2) passage. TIC tumor-initiating cell frequency, C.I. confidence interval.
