Characterization and distribution of CSC-representative markers related to the microenvironment.

<p>(A) Immunohistochemical results showed immunoreactivity of three CSC-representative markers (OCT-4, Nanog, and CD133) in the center of the primary tumor (a, b & c) (Magnification, 200×). Stronger immunoreactivity was shown at the invasive fronts (d, e & f) (Magnification, 200×) and many cancer cell clusters (arrows) in MPE at lower and higher magnifications (g, h & i). (Magnification, 40× and 400×). (<b>B</b>) Immunocytochemical characterization of cancer cell clusters in MPE showed three major combination groups (positive OCT-4, combined with positive or negative Nanog, and CD133 expressions) were identified: Group A, positive for all three CSC-representative markers (a, b &c); Group B, positive for OCT-4 and CD133, but negative for Nanog (d, e & f); Group C, positive for OCT-4, but negative for Nanog and CD133 (g, h & i) at lower and higher magnifications. (Magnification, 40× and 400×).