Fig. 3

LSR regulates cell proliferation and tumor growth through the MEK/ERK signaling pathway in endometrial cancer. A LSR-knockdown cells were generated by transfecting endometrial cancer cell lines (HEC1 and HEC116) with LSR-siRNA. We confirmed that the expression of LSR was suppressed in LSR-knockdown cells using western blot analysis. (The images of the western blot bands were cropped from the images shown in Supplemental Fig. S3A and B). B Cell proliferation was evaluated using the WST-8 assay at 72, 96, and 120 h following transfection. Cell proliferation was significantly suppressed in LSR-knockdown cells. Data were shown as means ± standard deviations (**p < 0.01). C Western blot analysis showed that in the MEK/ERK signaling pathway, the phosphorylation of MEK1/2, ERK1/2, and p90RSK was suppressed in LSR-knockdown cells. (The images of the western blot bands were cropped from the images shown in Supplemental Fig. S3C and D). D ERK1/2-knockdown also suppressed cell proliferation in HEC1 and HEC116 cells. Data were shown as means ± standard deviations (**p < 0.01). E Immunohistochemical analysis for phospho-ERK1/2 was performed using HEC1-xenograft tumors in nude mice. The rate of phospho-ERK1/2-positive cells was significantly lower in the anti-LSR mAb-treated group than in the control Ab-treated group (19.3% versus 61.8%, p < 0.01). Magnification, 400 X; Scale bar, 100 μm. Data were shown as means ± standard deviations (n = 5; **p < 0.01). Abbreviation: anti-LSR mAb, anti-LSR monoclonal antibody; control Ab, isotype control mouse IgG2a antibody; hr, hour; p-ERK1/2, phospho-ERK1/2; p-MEK1/2, phospho-MEK1/2; p-p90RSK, phospho-p90RSK