研究実績の概要 |
Initial results with the CXCR7 neutralizing antibody X7Ab suggested suppression of metastatic growth of the colon cancer cell line 2017 transplanted in NOG mice when compared with the control Rituximab antibody. However, the result was not doze dependent - the suppression effect was observed only with a doze of 2.4 mg/kg X7Ab and not with the higher doze of 5 mg/kg. A repetition of the experiment with 2.4 mg/kg X7Ab failed to replicate the previous results. Likewise, the CXCR7 inhibitor ACT-1004-1239 did not suppress metastatic growth of 2017. Detailed analysis suggested that the previously observed CXCR7 KO effects might be due to clonal differences in an intrinsically heterogeneous 2017 cell line. Moreover, RNAseq, real-time PCR and FACS sorting with X7Ab experiments demonstrated that 2017 displayed very low expression of CXCR7. Currently I am replicating the CXCR7 KO results in a separate cell line, 2044, which I verified to be expressing high levels of CXCR7. In vivo experiments with organoids expressing the in vivo labeling marker sLP-mCherry demonstrated stable expression of the marker, which however remained largely confined within the tumor and failed to label the surrounding host cells.
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今後の研究の推進方策 |
I verified high expression of CXCR7 in a separate cell line, 2044, isolated several clones from it and identified a clone with metastatic ability. I used this clone to knock out CXCR7, isolated and verified CXCR7 KO in several clones. I will proceed to compare the metastatic ability of the CXCR7 KO clones with the wild type clone. If the CXCR7 KO clones are indeed impaired in their metastatic ability, I will compare the RNA profiles of the CXCR7 KO with the wild type clone to identify potential pathways underlying the difference. Recent advances in spatial transcriptomic analysis techniques such as Xenium and Visium from 10X Genomics can bypass the need for labeling and extracting cancer-neighboring cells and help me identify CXCR7-dependent gene expression changes in host cells.
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