The exogenous promoter and the CDS of human CD37 was inserted to replace part of murine exon 3 and exons 4-7 in B-hCD37 MC38 cells. Human CD37 is highly expressed on the surface of B-hCD37 MC38 cells.

Gene targeting strategy for B-hCD37 MC38 cells. The exogenous promoter and the CDS of human CD37 were inserted to replace part of murine exon 3 and exons 4-7. The insertion disrupts the endogenous murine Cd37 gene, resulting in a non-functional transcript.

CD37 expression analysis in B-hCD37 MC38 cells by flow cytometry. Single cell suspensions from wild-type MC38 and B-hCD37 MC38 cultures were stained with species-specific anti-CD37 antibody. Human CD37 was detected on the surface of B-hCD37 MC38 cells but not wild-type MC38 cells. The 1-D11 clone of B-hCD37 MC38 cells was used for in vivo experiments.

Subcutaneous homograft tumor growth of B-hCD37 MC38 cells. B-hCD37 MC38 cells (2x10⁵, 5x10⁵, 3x10⁶) and wild-type MC38 cells (5x10⁵) were subcutaneously implanted into C57BL/6 mice (female, 8-week-old, n=8). 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 × long diameter × short diameter². As shown in panel A, B-hCD37 MC38 cells were able to establish tumors in vivo and can be used for efficacy studies. Values are expressed as mean ± SEM.

Subcutaneous homograft tumor growth of B-hCD37 MC38 cells. B-hCD37 MC38 cells and wild-type MC38 cells were subcutaneously implanted into B-hCD3E mice (female, 7-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 × long diameter × short diameter². As shown in panel A, B-hCD37 MC38 cells were able to establish tumors in vivo and can be used for efficacy studies. Values are expressed as mean ± SEM.