Low TMX1 expression accelerates tumor growth in vivo. (A) Quantification of surviving cells upon interference with mitochondria metabolism. HeLa cells and TMX1 heterozygous KO HeLa cells were incubated in medium supplemented with rotenone or antimycin and subsequently analyzed for positive Annexin V and propidium iodide signals. The amount of dead cells was normalized to the scrambled siRNA controls, and results from three independent experiments were graphed. n = 3; **, P = 0.02 for rotenone. n = 3; ***, P = 0.00 for antimycin. Standard error expressed versus scrambled Mock control. (B) Determination of medium acidification. HeLa cells and TMX1 heterozygous KO HeLa cells were plated into 24-well dishes, and the pH of the medium was determined after 24 and 48 h of culture (n = 3). Standard error expressed versus scrambled day 1. (C) Tumor growth of TMX1 HeLa KD clones in vivo. HeLa clones stably transfected with pcDNA3 or TMX1 shRNA (clones 4 and 7) were injected subcutaneously into the right and left flanks of athymic nude mice. The images show representative euthanized mice with their tumors marked on the side, and the graph summarizes the results of three animals each; standard error indicated. (D) Tumor growth of TMX1 A375P KD and overexpression (OE) clones in vivo. A375P clones stably transfected with pcDNA3, FLAG-tagged TMX1, or TMX1 shRNA were injected subcutaneously into the right and left flanks of athymic nude mice. The images show representative euthanized mice with their tumors marked on the side, and the graph summarizes the results of three animals each; standard error indicated.