Human breast cancer cells grow better in NSG mice than in nude mice.

<p>Human breast cancer cells were injected into the lactiferous duct of each of the fourth mammary glands in female nude or NSG mice. A. Tumor volume was measured starting at 21 days after injection of the cells. Breast cancer cells grew significantly faster in NSG mice (black squares) versus those growing in nude mice (open circles). Data are mean ± SEM. B. Tumors were weighed at the endpoint. The weight of tumors that arose in NSG mice were significantly larger than those grown in nude mice for all breast cancer cells examined. The increase in end tumor weight that arose from these cell lines grown in NSG mice was as follows: CN34BrM, 58%; MDA-MB-231, 65%; and SUM1315, 95%. The line indicates mean tumor weight. The mean is reported as the average of each tumor. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163521#pone.0163521.t002" target="_blank">Table 2</a> for the number of mice per group. **p<0.01, ***p<0.001. Please see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163521#sec002" target="_blank">Methods</a> for the statistical analysis performed.</p

Human breast cancer cells are more metastatic in NSG mice than in nude mice in an experimental metastasis model.

<p>MDA-MB-231 cells were injected into the heart of both nude (n = 7) and NSG (n = 8) mice and metastases were analyzed. A. Fluorescence images (white area is fluorescent tumors) were taken using a Zeiss SteroDiscovery.V12 fluorescence dissecting microscope with an AxioCam MRm digital camera. Representative images are shown from several different organs. Arrows, examples of numerous micrometastases in the lungs and brain of NSG mice (≤10 mm²). Bar, 2 mm. B. The metastases in the lungs, liver, brain (cranial and caudal) and bones (spine, ribs, scapula, radius, humerus, pelvis, femur and tibia) were enumerated for each mouse using Image J.</p

NSG mice have a higher metastatic burden than nude mice in a spontaneous metastasis model of breast cancer.

<p>Metastases were analyzed from the mice described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163521#pone.0163521.g001" target="_blank">Fig 1</a>. Fluorescent images as shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163521#pone.0163521.g002" target="_blank">Fig 2</a> were counted from each organ for each mouse in Image J. Metastases were counted in both the cranial and caudal side of the brain. Bone metastases were found in the spine, ribs, scapula, radius, humerus, pelvis, femur and tibia of NSG mice injected with MDA-MB-231 cells and only in the tibia and femur of NSG mice injected with SUM1315 cells. Statistics determined by an unpaired t-test. *p<0.05, **p<0.01, ****p<0.0001</p

Percent of mice with metastases from the mammary gland to specific organs.

<p>Percent of mice with metastases from the mammary gland to specific organs.</p

Comparison of immunodeficient mouse strains used in breast cancer research.

<p>Comparison of immunodeficient mouse strains used in breast cancer research.</p