The mouse Her2 gene was replaced by human HER2 coding sequence in B-hHER2 EL4 cells. Human HER2 is highly expressed on the surface of B-hHER2 EL4 cells.

Gene targeting strategy for B-hHER2 EL4 cells. The exogenous promoter and human HER2 coding sequence were inserted to replace part of murine exon 2 and all of exons 3~7. The insertion disrupts the endogenous murine Her2 gene, resulting in a non-functional transcript.

HER2 expression analysis in B-hHER2 EL4 cells by flow cytometry. Single cell suspensions from wild-type EL4 and B-hHER2 EL4 cultures were stained with species-specific anti-human HER2 antibody. Human HER2 was detected on the surface of B-hHER2 EL4 cells, but not on the surface of wild-type EL4 cells. The 2-H01 clone of B-hHER2 EL4 cells was used for in vivo experiments.

Subcutaneous homograft tumor growth of B-hHER2 EL4 cells. B-hHER2 EL4 cells (2x10⁵) and wild-type EL4 cells (2x10⁵) were subcutaneously implanted into C57BL/6 mice (female, 6-9-week-old, n=5). Tumor volume and body weight were measured twice a week. (A) Average tumor volume ± SEM. (B) Body weight (Mean ± SEM). Volume was expressed in mm³ using the formula: V=0.5 X long diameter X short diameter². As shown in panel A, B-hHER2 EL4 cells were able to establish tumors in vivo and can be used for efficacy studies.

Subcutaneous homograft tumor growth of B-hHER2 EL4 cells. B-hHER2 EL4 cells and wild-type EL4 cells were subcutaneously implanted into B-h4-1BB mice (female, 8-week-old, n=6). Tumor volume and body weight were measured twice a week. (A) Average tumor volume. (B) Body weight. Volume was expressed in mm³ using the formula: V=0.5 X long diameter X short diameter². As shown in panel A, B-hHER2 EL4 cells were able to establish tumors in vivo and can be used for efficacy studies. Values are expressed as mean ± SEM.

B-hHER2 EL4 tumor growth of individual mice. B-hHER2 EL4 cells (2x10⁵) and wild-type EL4 cells (2x10⁵) were subcutaneously implanted into C57BL/6 mice (female, 6-9-week-old, n=5). As shown in panel, B-hHER2 EL4 cells were able to establish tumors in vivo and can be used for efficacy studies.

B-hHER2 EL4 tumor growth of individual mice. B-hHER2 EL4 cells and wild-type EL4 cells were subcutaneously implanted into B-h4-1BB mice (female, 8-week-old, n=6). As shown in panel, B-hHER2 EL4 cells were able to establish tumors in vivo and can be used for efficacy studies.