Increased CSE1L expression enhanced the invasiveness and metastasis of cancer cells. (A) The levels of CSE1L expression in B16-EV, B16-CSE1L, COLO-EV, and COLO-CSE1L cells were assayed by immunoblotting with anti-CSE1L antibody. The β-actin levels were assayed as a control. The invasive ability of the cells was analyzed by in vitro invasion assays using chemotaxis chambers, as described in “Materials and Methods”. (B) Animal models showed that CSE1L regulated the metastasis of B16F10 cancer cells. The upper figure is a representative photograph of pulmonary tumors in C57BL/6 mice injected with B16-EV and B16-CSE1L cells. (C) In vivo metastasis study showed that CSE1L regulated the hepatic metastasis of HT-29 colon cancer cells in nude mice. Eight mice were injected with HT-29-EV cells and eight mice were injected with HT-29-CSE1L cells. One mouse injected with HT-29-CSE1L cells died 3 days after injection was excluded from the study. Metastatic tumors in the livers of SCID mice were examined 21 days after injection.