Hypoxia-inducible factor–dependent breast cancer–mesenchymal stem cell bidirectional signaling promotes metastasis
Pallavi Chaturvedi, … , Andre Levchenko, Gregg L. Semenza
Pallavi Chaturvedi, … , Andre Levchenko, Gregg L. Semenza
Published December 17, 2012
Citation Information: J Clin Invest. 2013;123(1):189-205. https://doi.org/10.1172/JCI64993.
View: Text | PDF | Corrigendum
Research Article

Hypoxia-inducible factor–dependent breast cancer–mesenchymal stem cell bidirectional signaling promotes metastasis

Abstract

Metastasis involves critical interactions between cancer and stromal cells. Intratumoral hypoxia promotes metastasis through activation of hypoxia-inducible factors (HIFs). We demonstrate that HIFs mediate paracrine signaling between breast cancer cells (BCCs) and mesenchymal stem cells (MSCs) to promote metastasis. In a mouse orthotopic implantation model, MSCs were recruited to primary breast tumors and promoted BCC metastasis to LNs and lungs in a HIF-dependent manner. Coculture of MSCs with BCCs augmented HIF activity in BCCs. Additionally, coculture induced expression of the chemokine CXCL10 in MSCs and the cognate receptor CXCR3 in BCCs, which was augmented by hypoxia. CXCR3 expression was blocked in cocultures treated with neutralizing antibody against CXCL10. Conversely, CXCL10 expression was blocked in MSCs cocultured with BCCs that did not express CXCR3 or HIFs. MSC coculture did not enhance the metastasis of HIF-deficient BCCs. BCCs and MSCs expressed placental growth factor (PGF) and its cognate receptor VEGFR1, respectively, in a HIF-dependent manner, and CXCL10 expression by MSCs was dependent on PGF expression by BCCs. PGF promoted metastasis of BCCs and also facilitated homing of MSCs to tumors. Thus, HIFs mediate complex and bidirectional paracrine signaling between BCCs and MSCs that stimulates breast cancer metastasis.

Authors

Pallavi Chaturvedi, Daniele M. Gilkes, Carmen Chak Lui Wong, Kshitiz, Weibo Luo, Huafeng Zhang, Hong Wei, Naoharu Takano, Luana Schito, Andre Levchenko, Gregg L. Semenza

×

Figure 1

MSCs are recruited to breast tumors and enhance lung and LN metastasis.

Options: View larger image (or click on image) Download as PowerPoint
MSCs are recruited to breast tumors and enhance lung and LN metastasis. ...
(A–C) MDA-231 BCCs were implanted into the MFP of SCID mice, which were treated with saline or digoxin (2 mg/kg/d). After 1 week of treatment, CMFDA-labeled human MSCs were injected via tail vein, and tumors were harvested 16 hours later. (A and B) Percent CMFDA+ MSCs in the primary tumor was analyzed by FACS (A) and by qPCR for SRY copy number (B). Data are mean ± SEM (n = 5). *P < 0.05, Student’s t test. (C) Labeled MSCs in tumor sections were detected by fluorescence microscopy. Scale bar: 1 mm. (D–I) SCID mice received MFP injection of 0.5 × 106 (0.5×) or 1 × 106 (1×) MDA-231 BCCs alone or 1 × 106 cells from 1:1 coculture of BCCs+MSCs. Mice were euthanized 56 days later, and tumors, lungs, and ipsilateral axillary LNs were harvested. (D) Tumor volume plotted against time (mean ± SEM; n = 5). (E) H&E staining of lung sections. Scale bar: 1 mm. (F) Metastatic foci in lung sections (≥3 random fields per section) were counted under ×20 magnification. (G) Metastatic burden was determined by qPCR using human HK2 gene primers. (H) Immunohistochemical analysis of LN sections with human-specific vimentin antibody. Scale bar: 0.5 mm. (I) Percent total LN area occupied by BCCs (mean ± SEM; n = 5). *P < 0.05, **P < 0.01 vs. 0.5 × 106 BCCs.