Fig. 6.

An ESCC PDX model to confirm the biomarkers of drug sensitivity. a Hematoxylin and eosin staining (HE) results of tumor tissue derived from an ESCC patient are shown. Magnification (right) is ×400. b The expression levels of p15 and p16 were detected by immunohistochemistry (IHC) staining in the FFPE tumor tissues of this ESCC patient. Magnification (right) is ×400. c Change in tumor volume following treatment with palbociclib in three doses in patient-derived xenografts (PDXs)-Z16062301 (28 days) (mean ± s.e.m., n = 10). Error bars correspond to standard error of the mean of tumor volume. *p < 0.01, Student’s t test, palbociclib 0 mg/kg compared with palbociclib 75 mg/kg; *p < 0.01, Student’s t test, palbociclib 75 mg/kg compared with palbociclib 150 mg/kg. d General picture of PDXs-Z16062301 after intragastric administration. e IHC staining of FFPE tumor tissue from PDXs treated with different dosages of palbociclib was used to detect the expression of p15, p16, and Ki67. The imaging results of IHC staining with the magnification of ×200 are shown