In vivo longitudinal and multimodal imaging of hypoxia-inducible factor 1α and angiogenesis in breast cancer
10.1097/CM9.0000000000000616
- Author:
Tang HE-WEN
1
;
Feng HAI-LIANG
;
Wang MING
;
Zhu QING-LI
;
Liu YU-QIN
;
Jiang YU-XIN
Author Information
1. Department of Ultrasound
- Keywords:
Breast cancer;
Hypoxia-inducible factor 1;
Pathological neovascularization;
Ultrasonography;
Fluorescence imaging
- From:
Chinese Medical Journal
2020;133(2):205-211
- CountryChina
- Language:Chinese
-
Abstract:
Background:Angiogenesis and hypoxia-inducible factor 1α (HIF-1α) play major roles in solid tumors.This study aimed to establish a longitudinal and multimodal imaging model for in vivo evaluation of HIF1α and angiogenesis in breast cancer.Methods:By transfection of a 5 hypoxia-responsive element (HRE)/green fluorescent protein (GFP) plasmid,the cell line Ca761-hregfp was established,which emitted green fluorescence triggered by HIF-1α under hypoxia.The cells were subjected to CoCl2-simulated hypoxia to confirm the imaging strategy.We grew Ca761-hre-gfp cells in the left rear flanks of twelve 615 mice.Experiments were conducted on days 4,9,15,and 19.For in vivo analysis,Ca761-hre-gfp subcutaneous allografted tumors were imaged in vivo using contrast-enhanced ultrasound (CEUS) and fluorescence imaging (FLI) during tumor development.The tumor size,CEUS peak intensity,and FLI photons were measured to evaluate rumor growth,angiogenesis,and HIF-1α activity,respectively.After each experiment,three mice were randomly sacrificed and tumor specimens were collected to examine HIF-1α activity and the microvessel density (MVD).Results:In vitro,both green fluorescence and HIF-1α expression were detected in Ca761-hre-gfp cells treated with CoCl2,indicating the suitability of the cells to detect HIF-1α activity.In vivo,HIF-1α activity first increased and then decreased,which was significantly correlated with angiogenic changes (r =0.803,P =0.005).These changes were confirmed by immunohistochemical staining of HIF-1α and MVD.Conclusions:The findings validated the Ca761-hre-gfp murine allograft model for reliable evaluation of HIF-1α activity and angiogenesis longitudinally using both molecular and pre-clinical non-invasive imaging modalities.The cell line may be useful for studies of anti-HIF pathway therapies.
