Fig. 1
Frequency of CIC structures, senescent and apoptotic cells assessed by immunohistochemistry. a E-Cadherin staining labelling numerous CIC structures in HNSCC and magnifications of indicated region. (ai) Schematic drawing of a CIC structure illustrating defining criteria: complete encirclement of the inner cell by the host cell membrane, circular shape of the inner cell and semilunar host cell nucleus. b Cleaved caspase-3 labeled HNSCC and magnifications of indicated region showing CIC structures negative for cleaved caspase-3. c H3K9ME labeled HNSCC showing senescent cells and magnifications of indicated region. d Ki67 labeled HNSCC showing proliferating cells and magnifications of indicated region. Comparative analysis of (e) CIC structures, (f) senescent cells, (g) apoptotic cells, (h) proliferating cells and (j) tumor cells in the center of the tumor (pre- and post-RCT) and invasive front (pre-RCT). k Comparison of ratio of CIC structures, senescent cells and apoptotic cells in the center of the tumor and invasive front compared to frequency of CIC structures in the center of the tumor pre-RCT as a reference