Description 

The mouse Cxcr4 gene was replaced by human CXCR4 coding sequence in B-hCXCR4 MC38 cells. Human CXCR4 is highly expressed on the surface of B-hCXCR4 MC38 cells.

Application
B-hCXCR4 MC38 cells have the capability to establish tumors in vivo and can be used for efficacy studies.
Targeting strategy
Gene targeting strategy for B-hCXCR4 MC38 cells. The exogenous promoter and human CXCR4 coding sequence was inserted to replace part of murine exon 2. The insertion disrupts the endogenous murine Cxcr4 gene, resulting in a non-functional transcript.

Protein expression analysis

CXCR4 expression analysis in B-hCXCR4 MC38 cells by flow cytometry. Single cell suspensions from wild-type MC38 and B-hCXCR4 MC38 cultures were stained with species-specific anti-CXCR4 antibody. Human CXCR4 was detected on the surface of B-hCXCR4 MC38 cells but not wild-type MC38 cells. The 2-B07 clone of B-hCXCR4 MC38 cells was used for in vivo experiments.

Tumor growth curve & Body weight changes

Subcutaneous homograft tumor growth of B-hCXCR4 MC38 cells. B-hCXCR4 MC38 cells (5x10⁵, 1X10⁶, 5X10⁶) and wild-type MC38 cells (5x10⁵) were subcutaneously implanted into C57BL/6 mice (female, 7-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-hCXCR4 MC38 cells were able to establish tumors in vivo and can be used for efficacy studies.

Protein expression analysis of tumor cells

B-hCXCR4 MC38 cells were subcutaneously transplanted into C57BL/6 mice (n=5). At the end of the experiment, tumor cells were harvested and assessed for human CXCR4 expression by flow cytometry. As shown, human CXCR4 was highly expressed on the surface of tumor cells. Therefore, B-hCXCR4 MC38 cells can be used for in vivo efficacy studies of novel CXCR4 therapeutics.