The mouse Cd38 gene was replaced by chimeric CD38 coding sequence in B-hCD38 MC38 cells. Human CD38 is highly expressed on the surface of B-hCD38 MC38 cells.

Gene targeting strategy for B-hCD38 MC38 cells. The exogenous promoter and chimeric CD38 coding sequence were inserted to replace part of murine exon 2 and all of exon 3. The insertion disrupts the endogenous murine Cd38 gene, resulting in a non-functional transcript.

CD38 expression analysis in B-hCD38 MC38 cells by flow cytometry. Single cell suspensions from wild-type MC38 and B-hCD38 MC38 cultures were stained with species-specific anti-CD38 antibody. Mouse CD38 was detected on the surface of wild-type MC38 cells. Human CD38 was detected on the surface of B-hCD38 MC38 cells but not wild-type MC38 cells. The 4-F06 clone of B-hCD38 MC38 cells was used for in vivo experiments.

Subcutaneous homograft tumor growth of B-hCD38 MC38 cells. B-hCD38 MC38 cells (5x10⁵) and wild-type MC38 cells (5x10⁵) were subcutaneously implanted into C57BL/6N mice (female, 7-8-week-old, n=6). 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 × long diameter × short diameter². As shown in panel A, B-hCD38 MC38 cells were able to establish tumors in vivo and can be used for efficacy studies.

Subcutaneous homograft tumor growth of B-hCD38 MC38 cells. B-hCD38 MC38 cells (5x10⁵ or 1x10⁶) and wild-type MC38 cells (5x10⁵) were subcutaneously implanted into B-hCD16A mice (female, 6-7-week-old, n=8). 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 × long diameter × short diameter². As shown in panel A, B-hCD38 MC38 cells were able to establish tumors in vivo and can be used for efficacy studies.

Subcutaneous homograft tumor growth of B-hCD38 MC38 cells. B-hCD38 MC38 cells (5x10⁵ or 1x10⁶) and wild-type MC38 cells (5x10⁵) were subcutaneously implanted into B-hCD16A mice (female, 6-7-week-old, n=8). 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 × long diameter × short diameter². As shown in panel A, B-hCD38 MC38 cells were able to establish tumors in vivo and can be used for efficacy studies.