Fig. 6

Therapeutic effect of gefitinib and usefulness of CYLD as a novel biomarker in xenograft models. A, B SAS cells were injected subcutaneously into SCID mice (n = 6). After 7 days from cells injection, the tumor-inoculated CDX models were injected intraperitoneally with 2.5 mg gefitinib or DMSO, and tumor volume were measured at 14 days (A) in a time-dependent manner (B). Values are means ± S.D. of triplicate samples. **p < 0.01 in Tukey Kramer test. C Kaplan–Meier plot of overall survival of CDX models. **p < 0.01 siCYLD control group vs siCYLD gefitinib group in log-rank test. D PDX-derived cells (PDX st.1 & PDX st.2) were treated with gefitinib, and the cell survival rates were assessed 48 h after treatment. Values Scale bar shows 200 µm. Values are means ± S.D. of triplicate samples. **p < 0.01 in Tukey–Kramer method. E Immunohistochemical analysis for CYLD expression in tumor tissues from PDX models (PDX st.1 & PDX st.2). CYLD positive rates were be calculated by ImageJ. Boxplots represented the first, second, and third quartiles, and whiskers extended to maximum value and minimum value except for outliers. Values Scale bar shows 40 µm. **p < 0.01 in Mann–Whitney U test. F Schematic model illustrating novel therapeutic strategies for CYLD-negative OSCC patients with poor prognosis