Abstract
Although the skeleton is one of the predominant sites for breast cancer metastasis, why breast cancer cells often become dormant after homing to bone is not well understood. Here, we reported an intrinsic self-defense mechanism of bone cells against breast cancer cells: a critical role of connexin (Cx) 43 hemichannels in osteocytes in the suppression of breast cancer bone metastasis. Cx43 hemichannels allow passage of small molecules between the intracellular and extracellular environments. The treatment of bisphosphonate drugs, either alendronate (ALN) or zoledronic acid (ZOL), opened Cx43 hemichannels in osteocytes. Conditioned media (CM) collected from MLO-Y4 osteocyte cells treated with bisphosphonates inhibited the anchorage-independent growth, migration and invasion of MDA-MB-231 human breast cancer cells and Py8119 mouse mammary carcinoma cells, and this inhibitory effect was attenuated with Cx43(E2), a specific hemichannel-blocking antibody. The opening of osteocytic Cx43 hemichannels by mechanical stimulation had similar inhibitory effects on breast cancer cells and this inhibition was attenuated by Cx43(E2) antibody as well. These inhibitory effects on cancer cells were mediated by ATP released from osteocyte Cx43 hemichannels. Furthermore, both Cx43 osteocyte-specific knockout mice and osteocyte-specific Δ130-136 transgenic mice with impaired Cx43 gap junctions and hemichannels showed significantly increased tumor growth and attenuated the inhibitory effect of ZOL. However, R76W transgenic mice with functional hemichannels but not gap junctions in osteocytes did not display a significant difference. Together, our studies establish the specific inhibitory role of osteocytic Cx43 hemichannels, and exploiting the activity of this channel could serve as a de novo therapeutic strategy.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 50 print issues and online access
$259.00 per year
only $5.18 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Welch DR, Harms JF, Mastro AM, Gay CV, Donahue HJ . Breast cancer metastasis to bone: evolving models and research challenges. J Musculoskelet Neuronal Interact 2003; 3: 30–38.
Roodman GD . Mechanism of bone metastasis. N Engl J Med 2004; 350: 1655–1664.
van der Pluijm G, Sijmons B, Vloedgraven H, Deckers M, Papapoulos S, Lowik C . Monitoring metastatic behavior of human tumor cells in mice with species-specific polymerase chain reaction: elevated expression of angiogenesis and bone resporption stimulators by breast cancer in bone metastases. J Bone Miner Res 2001; 16: 1077–1091.
Theriault RL, Theriault RL . Biology of bone metastases. Cancer Control 2012; 19: 92–101.
Place AE, Jin HS, Polyak K . The microenvironment in breast cancer progression: biology and implications for treatment. Breast Cancer Res 2011; 13: 227.
Bonewald LF . Osteocytes as dynamic multifucntional cells. Ann NY Acad Sci 2007; 1116: 281–290.
Matsuo K . Cross-talk among bone cells. Curr Opin Nephrol Hypertens 2009; 18: 292–297.
Goodenough DA, Goliger JA, Paul DL . Connexins, connexons, and intercellular communication. Annu Rev Biochem 1996; 65: 475–502.
Goodenough DA, Paul DL . Beyond the gap: functions of unpaired connexon channels. Nat Rev Mol Cell Biol 2003; 4: 285–294.
Evans WH, de Vuyst E, Leybaert L . The gap junction cellular internet: connexin hemichannels enter the signaling limelight. Biochem J 2006; 397: 1–14.
Saez JC, Berthoud VM, Branes MC, Martinez AD, Beyer EC . Plasma membrane channels formed by connexins: their regulation and functions. Physiol Rev 2003; 83: 1359–1400.
Cherian PP, Siller-Jackson AJ, Gu S, Wang X, Bonewald LF, Sprague E et al. Mechanical strain opens connexin 43 hemichannels in osteocytes: a novel mechanism for the release of prostaglandin. Mol Biol Cell 2005; 16: 3100–3106.
Genetos DC, Kephart CJ, Zhang Y, Yellowley CE, Donahue HJ . Oscillating fluid flow activation of gap junction hemichannels induces ATP release from MLO-Y4 osteocytes. J Cell Physiol 2007; 212: 207–214.
Siller-Jackson AJ, Burra S, Gu S, Xia X, Bonewald LF, Sprague E et al. Adaptation of connexin 43-hemichannel prostaglandin release to mechanical loading. J Biol Chem 2008; 283: 26374–26382.
Plotkin LI, Manolagas SC, Bellido T . Transduction of cell survival signals by connexin-43 hemichannels. J Biol Chem 2002; 277: 8648–8657.
Brown SA, Guise TA . Cancer-associated bone disease. Curr Osteoporos Rep 2007; 5: 120–127.
Mesnil M . Connexins and cancer. Biol Cell 2002; 94: 493–500.
Mesnil M, Crespin S, Avanzo JL, Zaidan-Dagli ML . Defective gap junctional intercellular communication in the carcinogenic process. Biochim Biophys Acta 2005; 1719: 125–145.
Cronier L, Crespin S, Strale P-O, Defamie N, Mesnil M . Gap junctions and cancer: new functions for an old story. Antioxid Redox Signal 2009; 11: 323–328.
Laird DW, Fistouris P, Batist G, Alpert L, Huynh HT, Carystinos G et al. Deficiency of connexin43 gap junctions is an independent marker for breast tumors. Cancer Res 1999; 59: 4104–4110.
Elzarrad MK, Haroon A, Willecke K, Dobrowolski R, Gillespie MN, Al-Mehdi AB . Connexin-43 upregulation in micrometastases and tumor vasculature and its role in tumor cell attachment to pulmonary endothelium. BMC Med 2008; 6: 20.
Stoletov K, Strnadel J, Zardouzian E, Momiyama M, Park FD, Kelber JA et al. Role of connexins in metastatic breast cancer and melanoma brain colonization. J Cell Sci 2013; 126: 904–913.
Avanzo JL, Mesnil M, Hernandez-Blazquez FJ, Mackowiak II, Mori CM, da Silva TC et al. Increased susceptibility to urethane-induced lung tumors in mice with decreased expression of connexin43. Carcinogenesis 2004; 25: 1973–1982.
Plante I, Stewart MKG, Barr K, Allan AL, Laird DW . Cx43 suppresses mammary tumor metastasis to the lung in a Cx43-mutant mouse model of human disease. Oncogene 2011; 30: 1681–1692.
Plotkin LI, Bellido T . Bisphophonate-induced, hemichannel-mediated anti-apoptosis through the Src/ERK pathway: a gap junction-independent action of connexin43. Cell Commun Adhes 2001; 2001: 377–382.
Riquelme MA, Kar R, Gu S, Jiang JX . Antibodies targeting extracellular domain of connexins for studies of hemichannels. Neuropharmacology 2013; 75: 525–532.
Savariar EN, Felsen CN, Nashi N, Jiang T, Ellies LG, Steinbach P et al. Real-time in vivo molecular detection of primary tumors and metastases with ratiometric activatable cell-penetrating peptides. Cancer Res 2013; 73: 855–864.
Kato Y, Boskey A, Spevak L, Dallas M., Hori M, Bonewald LF . Establishment of an osteoid preosteocyte-like cell MLO-A5 that spontaneously mineralized in culture. J Bone Miner Res 2001; 16: 1622–1633.
Cherian PP, Xia X, Jiang JX . Role of gap junction, hemichannels, and connexin 43 in mineralizing in response to intermittent and continuous application of parathyroid hormone. Cell Commun Adhes 2008; 15: 43–54.
Kohno N . Treatment of breast cancer with bone metastasis: bisphosphonate treatment—current and future. Int J Clin Oncol 2008; 13: 18–23.
Russell RG . Bisphosphonates: the first 40 years. Bone 2011; 49: 2–19.
Zhou JZ, Riquelme MA, Gao X, Ellies LG, Sun LZ, Jiang JX . Differential impact of adenosine nucleotides released by osteocytes on breast cancer growth and bone metastasis. Oncogene 2015; 34: 1831–1842.
Aarden EM, Burger EH, Nijweide PJ . Function of osteocytes in bone. J Cell Biochem 1994; 55: 287–299.
Klein-nulend J, Bakker AD, Bacabac RG, Vatsa A, Weinbaum S . Mechanosensation and transduction in osteocytes. Bone 2013; 54: 182–190.
Jiang JX, Siller-Jackson AJ, Burra S . Roles of gap junctions and hemichannels in bone cell functions and in signal transmission of mechanical stress. Front Biosci 2007; 12: 1450–1462.
Cheng B, Zhao S, Luo J, Sprague E, Bonewald LF, Jiang JX . Expression of functional gap junctions and regulation by fluid flow shear stress in osteocyte-like MLO-Y4 cells. J Bone Miner Res 2001; 16: 249–259.
Bivi N, Condon KW, Allen MR, Farlow N, Passeri G, Brun LR et al. Cell autonomous requirement of connexin 43 for osteocyte survival: consequences for endocortical resorption and periosteal bone formation. J Bone Miner Res 2012; 27: 374–389.
Xu H, Gu S, Riquelme MA, Burra S, Callaway D, Cheng H et al. Connexin 43 channels are essential for normal bone structure and osteocyte viability. J Bone Miner Res 2015; 30: 436–448.
Joyce JA, Pollard JW . Microenvironmental regulation of metastasis. Nat Rev Cancer 2009; 9: 239–252.
Liotta LA, Kohn EC . The microenvironment of the tumour-host interface. Nature 2001; 411: 375–379.
Paget S . The distribution of secondary growths in cancer of the breast. Lancet 1889; 1: 571–573.
Bonewald LF . The amazing osteocyte. J Bone Miner Res 2011; 26: 229–238.
Bennett MV, Garre JM, Orellana JA, Bukauskas FF, Nedergaard M, Saez JC . Connexin and pannexin hemichannels in inflammatory responses of glia and neurons. Brain Res 2012; 1487: 3–15.
Calder BW, Matthew RJ, Bainbridge H, Fann SA, Gourdie RG, Yost MJ . Inhibition of connexin 43 hemichannel-mediated ATP release attenuates early inflammation during the foreign body response. Tissue Eng Part A 2015; 21: 1752–1762.
Stains JP, Civitelli R . Gap junctions in skeletal development and function. Biochim Biophys Acta 2005; 1719: 69–81.
Laird DW . Life cycle of connexins in health and disease. Biochem J 2006; 394: 527–543.
Chung DJ, Castro CH, Watkins M, Stains JP, Chung MY, Szejnfeld VL et al. Low peak bone mass and attenuated response to parathyroid hormone in mice with an osteoblast-specific deletion of connexin43. J Cell Sci 2006; 119: 4187–4198.
Bivi N, Pacheco-Costa R, Brun LR, Murphy TR, Farlow NR, Robling AG et al. Absence of Cx43 selectively from osteocytes enhances responsiveness to mechanical force in mice. J Orthop Res 2013; 31: 1075–1081.
Zhang Y, Paul EM, Sathyendra V, Davison A, Sharkey N, Bronson S et al. Enhanced osteoclastic resorption and responsiveness to mechanical load in gap junction deficient bone. PLoS One 2011; 6: e23516.
Loiselle AE, Paul EM, Lewis GS, Donahue HJ . Osteoblast and osteocyte-specific loss of Connexin43 results in delayed bone formation and healing during murine fracture healing. J Orthop Res 2013; 31: 147–154.
Orellana JA, Shoji KF, Abudara V, Ezan P, Amigou E, Sáez PJ et al. Amyloid β-induced death in neurons involves glial and neuronal hemichannels. J Neurosci 2011; 31: 4962–4977.
Orellana JA, Froger N, Ezan P, Jiang JX, Bennett MV, Naus CC et al. ATP and glutamate released via astroglial connexin 43hemichannels mediate neuronal death through activation of pannexin 1 hemichannels. J Neurochem 2011; 118: 826–840.
Orellana JA, Sáez PJ, Cortés-Campos C, Elizondo RJ, Shoji KF, Contreras-Duarte S et al. Glucose increase intracellular free Ca(2+) in tanycytes via ATP released through connexin 43 hemichannels. Glia 2012; 60: 53–68.
Kato Y, Windle JJ, Koop BA, Mundy GR, Bonewald LF . Establishment of an osteocyte-like cell line, MLO-Y4. J Bone Miner Res 1997; 12: 2014–2023.
Shabbir M, Burnstock G . Purinergic receptor-mediated effects of adenosine 5'-triphosphate in urological malignant diseases. Int J Urol 2009; 16: 143–150.
White N, Burnstock G . P2 receptors and cancer. Trends Pharmacol Sci 2006; 27: 211–217.
Rapaport E, Fishman RF, Gercel C . Growth inhibition of human tumor cells in soft-agar cultures by treatment with low levels of adenosine 5'-triphosphate. Cancer Res 1983; 43: 4402–4406.
Saez JC, Contreras JE, Bukauskas FF, Retamal MA, Bennett MVL . Gap junction hemichannels in astrocytes of the CNS. Acta Physiol Scand 2003; 179: 9–22.
Plotkin LI . Connexin 43 hemichannels and intracellular signaling in bone cells. Front Physiol 2014; 5: 131.
D'hondt C, Iyyathurai J, Himpens B, Leybaert L, Bultynck G . Cx43-hemichannel function and regulation in physiology and pathophysiology: insights from the bovine corneal endothelial cell system and beyond. Front Physiol 2014; 5: 348.
Sterling JA, Guelcher SA . Bone structural components regulating sites of tumor metastasis. Curr Osteoporos Rep 2011; 9: 89–95.
Milne HM, Wallman KE, Gordon S, Courneya KS . Effects of a combined aerobic and resistance exercise program in breast cancer survivors: a randomized controlled trial. Breast Cancer Res Treat 2008; 108: 279–288.
Schwartz AL, Winters-Stone K, Gallucci B . Exercise effects on bone mineral density in women with breast cancer receiving adjuvant chemotherapy. Oncol Nurs Forum 2007; 34: 627–633.
Holick CN, Newcomb PA, Trentham-Dietz A, Titus-Ernstoff L, Bersch AJ, Stampfer MJ et al. Physical activity and survival after diagnosis of invasive breast cancer. Cancer Epidemiol Biomarkers Prev 2008; 17: 379–386.
Irwin ML, McTiernan A, Manson JE, Thomson CA, Sternfeld B, Stefanick ML et al. Physical activity and survival in postmenopausal women with breast cancer: results from the women's health initiative. Cancer Prev Res (Phila) 2011; 4: 522–529.
Lynch ME, Brooks D, Mohanan S, Lee MJ, Polamraju P, Dent K et al. In vivo tibial compression decreases osteolysis and tumor formation in a human metastatic breast cancer model. J Bone Miner Res 2013; 28: 2357–2367.
Kretschmann KL, Welm AL . Mouse models of breast cancer metastasis to bone. Cancer Metastasis Rev 2012; 31: 579–583.
Xu H, Gu S, Riquelme MA, Burra S, Callaway D, Cheng H et al. Connexin 43 channels are essential for normal bone structure and osteocyte viability. J Bone Miner Res 2014; 30: 436–448.
Dbouk HA, Mroue RM, El Sabban ME, Talhouk RS . Connexins: a myriad of functions extending beyond assembly of gap junction channels. Cell Commun Signal 2009; 7: 4.
Zhou JZ, Jiang JX . Gap junction and hemichannel-independent actions of connexins on cell and tissue functions—an update. FEBS Lett 2014; 588: 1186–1192.
Zhang W, Tan S, Paintsil E, Dutschman GE, Gullen EA, Chu E et al. Analysis of deoxyribonucleotide pools in human cancer cell lines using a liquid chromatography coupled with tandem mass spectrometry technique. Biochem Pharmacol 2011; 82: 411–417.
Theis M, de Wit C, Schlaeger TM, Eckardt D, Krüger O, Döring B et al. Endothelium-specific replacement of the connexin43 coding region by a lacZ reporter gene. Genesis 2001; 29: 1–13.
Yang W, Kalajzic I, Lu Y, Guo D, Harris MA, Gluhak-Heinrich J et al. Identification of an osteocyte-specific mechanically regulated region of the dentin matrix protein 1 gene. J Biol Chem 2005; 280: 20680–20690.
Guise TA, Yin JJ, Taylor SD, Kumagai Y, Dallas M, Boyce BF et al. Evidence for a causal role of parathyroid hormone-related protein in the pathogenesis of human breast cancer-mediated osteolysis. J Clin Invest 1996; 98: 1544–1549.
Acknowledgements
We thank Hongyun Cheng for technical assistance, Dr Lesley Ellies at the University of California at San Diego for providing Py8119 cells, Dr Lynda Bonewald at the University of Missouri at Kansas City for MLO-Y4 osteocytic cells, Dr Stephen Harris at UTHSCSA for 10-kb dentin matrix protein 1 (DMP1)-Cre mice and Dr Klaus Willecke at the University of Bonn and Dr Roberto Civitelli for mice with floxed Cx43 gene. The work was supported by Welch Foundation grant AQ-1507 and NIH grant EY012085 to JXJ, ES022057 to LZS and the NCI Cancer Center grant 2 P30 CA054174-17 to Cancer Therapy and Research Center.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests
The authors declare no conflict of interest.
Additional information
Supplementary Information accompanies this paper on the Oncogene website
Supplementary information
Rights and permissions
About this article
Cite this article
Zhou, J., Riquelme, M., Gu, S. et al. Osteocytic connexin hemichannels suppress breast cancer growth and bone metastasis. Oncogene 35, 5597–5607 (2016). https://doi.org/10.1038/onc.2016.101
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/onc.2016.101
This article is cited by
-
Pathways Controlling Formation and Maintenance of the Osteocyte Dendrite Network
Current Osteoporosis Reports (2022)
-
Microfluidic Co-culture Platforms for Studying Osteocyte Regulation of Other Cell Types under Dynamic Mechanical Stimulation
Current Osteoporosis Reports (2022)
-
Mechanotransduction via the coordinated actions of integrins, PI3K signaling and Connexin hemichannels
Bone Research (2021)
-
Mechanobiology of Bone Metastatic Cancer
Current Osteoporosis Reports (2021)
-
Role of Osteocytes in Cancer Progression in the Bone and the Associated Skeletal Disease
Current Osteoporosis Reports (2021)