Patient-derived xenograft culture-transplant system for investigation of human breast cancer metastasis.

Metastasis is a fatal disease where research progress has been hindered by a lack of authentic experimental models. Here, we develop a 3D tumor sphere culture-transplant system that facilitates the growth and engineering of patient-derived xenograft (PDX) tumor cells for functional metastasis assays in vivo. Orthotopic transplantation and RNA sequencing (RNA-seq) analyses show that PDX tumor spheres maintain tumorigenic potential, and the molecular marker and global transcriptome signatures of native tumor cells. Tumor spheres display robust capacity for lentiviral engineering and dissemination in spontaneous and experimental metastasis assays in vivo. Inhibition of pathways previously reported to attenuate metastasis also inhibit metastasis after sphere culture, validating our approach for authentic investigations of metastasis. Finally, we demonstrate a new role for the metabolic enzyme NME1 in promoting breast cancer metastasis, providing proof-of-principle that our culture-transplant system can be used for authentic propagation and engineering of patient tumor cells for functional studies of metastasis.

Contrast-enhanced ultrasound to assess gallbladder polyps.

PURPOSE: To assess the value of contrast-enhanced ultrasound (CEUS) in distinguishing adenomatous gallbladder polyps from cholesterol gallbladder polyps. METHODS: A total of 164 patients with gallbladder polyps were retrospectively analyzed. All patients underwent B-mode ultrasound (US) and CEUS before cholecystectomy. Gallbladder polyps were divided into cholesterol polyp group and adenomatous polyp group according to pathology. Differences in patient's age, gender, maximum polyp size, number, presence of gallstones, vascularity and stalk width measured by US and vascular stalk width measured by CEUS were tested between the two groups. The diagnostic performance of specific US features was evaluated. The independent factors related with adenomatous polyps were analyzed by multiple logistic regression analyses. RESULTS: There were 114 cholesterol polyps and 50 adenomatous polyps in 164 patients analyzed in the study. Differences in maximum size, vascularity, and stalk width of the gallbladder polyp were significant between the two groups (p < 0.05), whereas differences in patient's age, gender, number of gallbladder polyp, and presence of gallstones between the two groups were not (p > 0.05). Stalk width was wider than vascular stalk width between the two groups (p < 0.05). Vascular stalk width was also statistically different between the two groups (p < 0.05). The diagnostic performance of vascular stalk width was more significant than stalk width. Only vascular stalk width and vascularity were independent factors related with adenomatous polyps. CONCLUSION: Vascular stalk width measured by CEUS is more accurate than stalk width measured by grayscale US in distinguishing adenomatous polyps from cholesterol polyps.