STIM1 is reduced in tumor invading-edge and metastatic HCC cells. (A) Representative micrographs of STIM1 immunohistochemical analysis (400×) and statistical analysis of integrated optical density (IOD) of STIM1 against immunoglobulin G (IgG) in the invading edge and tumor of 12 HCC patients. (B) IOD of STIM1 against IgG in the tumor invading-edge of portal vein tumor thrombus (PVTT)-positive (n = 4) and PVTT-negative (n = 8) HCC samples. (C) Snail1 and STIM1 mRNA, (D) E-cadherin, Snail1 and STIM1 protein expressions were detected in SMMC7721, HepG2, Hep3B and BEL-7404 treated with TGF-β1 for 48 h. The results were analyzed and normalized against expression with 20 ng/mL bovine serum albumin (BSA) treated cells. (E) Diagram that the isolation different metastatic sublines from SMMC7721 cells after 4 rounds of selection, LM: low metastatic, HM: high metastatic. (F) Metastatic characteristic of LM- and HM-SMMC7721 sublines in vivo, lungs were observed for metastatic nodules on the surface, representative photographs and H&E staining were shown (n = 4 mice per group), arrows point to metastatic nodules. (G, H) The mRNA (G) and protein (H) expressions of STIM1, Snail1 and E-cadherin in LM- and HM-SMMC7721 sublines. (I) Kaplan-Meier analysis of correlation between the STIM1 expression and overall survival of HCC patients from TGCA (n = 360). Data of (A-D, G and H) are expressed as mean ± SEM (n = 3). *p < 0.05, **p <0.01, ***p < 0.001, NS represents no significant difference.