Fig. 1: Characteristic expression of MTH1 in human gastric cancer tissues and ten digestive tract cancer cell lines.

a The total RNA from fresh human gastric cancer tissues was isolated by RNApure Tissue&Cell Kit. The mRNA level of MTH1 in human gastric cancer (Increased, n = 21, Decreased, n = 6 and Unchanged, n = 8) and adjacent normal tissues (Con, n = 35) was determined by RT-PCR. The protein levels of MTH1 in human gastric (GC) and adjacent normal (GN) tissue sections were determined by immuohistochemistry (IHC) staining. The integral optical densities (IOD) were analyzed by Image-Pro Plus 6.0 software. b Representative IHC pictures of GC and GN. Scale bars, 50 μm. c IODs of GC and GN. n = 10 for each group. The cells from esophageal cancer cell lines: KYSE-450, EC109 and EC9706 (d, e), liver cancer cell lines: SMMC-7721, HepG2 and ZIP177 (f, g), gastric cancer cell lines: MGC-803, HGC-27, SGC-7901 and MKN45 (h, i), as well as the corresponding normal cell lines: Het-1A (d, e), L02 (f, g) and GES-1 (h, i) were cultured and lysed. The MTH1 protein levels were determined by Western Blot. GAPDH was used as a loading control. At least three independent experiments were performed for each group. j The cells indicated above were lysed and the total mRNA was extracted. The mRNA level of MTH1 was determined by RT-PCR. GAPDH was used as a control. At least three independent experiments were performed for each group. Data are presented as means ± SD. The symbol *, ** or *** stands for P < 0.05, P < 0.01 or P < 0.001 compared with the controls or normal cell groups