FIGURE 6.

Molecular events for tumour cell repopulation correlate with poor clinical outcome. (A) The levels of X‐box binding protein‐1 (XBP1), amphiregulin (AREG) and basic fibroblast growth factor (bFGF) in representative cancer specimens were examined by immunohistochemistry (IHC) assays. Scale bar = 50 µm. (B) The correlation between the expression levels of XBP1s and AREG or bFGF was analysed. (C) The average IHC values of each protein (XBP1s, AREG, bFGF) in 88 tongue cancer tissues were obtained, and IHC scores above the average value indicated high expression, otherwise indicated low expression. Kaplan–Meier analysis indicated a correlation between XBP1s/AREG/bFGF levels and overall survival in patients with tongue cancer. Kaplan–Meier survival analysis is shown here with a two‐sided log‐rank p‐value. (D) The protein levels of AREG and bFGF in serum were examined by enzyme‐linked immunosorbent assay (ELISA) (n = 3), ^** p < .01, ^*** p < .001. Data are presented as the mean value ± SEM. Statistical significance was determined by a two‐tailed Student's t‐test. (E) The correlation between the XBP1s/AREG/bFGF levels and tongue cancer recurrence was analysed. (F) Fifteen paired tissues of primary tongue cancer and recurrent tongue cancer were collected. The protein levels of p65, IκBα and lysine acetyltransferase 6B (KAT6B) were examined by IHC assays. The transcript levels of miR‐22‐3p, XLOC_003973 and XLOC_010383 were examined by in situ hybridisation (ISH) assays. Scale bars = 50 µm