Contrast-enhanced ultrasound for the evaluation of CXCR7-mediated angiogenesis in colon cancer

Background: The purpose of this study was to clarify the effect of C-X-C chemokine receptor type 7 (CXCR7) on proliferation, migration, and angiogenesis by changing the expression levels of CXCR7 in colon cancer cells. Contrast-enhanced ultrasound technology was used to quantify tumor perfusion parameters in vivo for the detection of angiogenesis after the change of CXCR7 expression in colon cancer xenografts. Methods: To detect the expression of CXCR7 in colon cancer cells after overexpression or silencing of CXCR7. In addition, proliferation, migration, and angiogenesis were determined. The region of interest of the tumor was selected, and a time-intensity curve was drawn. Immunohistochemical staining was performed on tumor tissue sections, and the average microvessel density value was calculated. Results: Overexpression or silencing of CXCR7 altered the proliferation, migration, and luminal formation of Caco-2 and SW480 cells. In xenografts produced using CXCR7-overexpressing or -silent Caco-2 and SW480, respectively, the peak intensity and area under the curve were significantly different. The expression of CXCR7, VEGF, Ki67, and CD34 was decreased in CXCR7-silent cells, but increased in CXCR7-overexpressing cells. CXCR7 apparently affected angiogenesis through the extracellular signal regulated kinase pathway. Conclusions: The regulation of CXCR7 expression may affect the proliferation, migration, and luminal formation of Caco-2 and SW480 cells, indicating that CXCR7 may play an important role in colon cancer. Examination through contrast-enhanced ultrasound also demonstrated that the expression of CXCR7 is closely related to angiogenesis.