TY - JOUR
T1 - Integrin β7-mediated regulation of multiple myeloma cell adhesion, migration, and invasion
AU - Neri, Paola
AU - Ren, Li
AU - Azab, Abdel Kareem
AU - Brentnall, Matthew
AU - Gratton, Kathy
AU - Klimowicz, Alexander C.
AU - Lin, Charles
AU - Duggan, Peter
AU - Tassone, Pierfrancesco
AU - Mansoor, Adnan
AU - Stewart, Douglas A.
AU - Boise, Lawrence H.
AU - Ghobrial, Irene M.
AU - Bahlis, Nizar J.
PY - 2011/6/9
Y1 - 2011/6/9
N2 - Integrin-β7 (ITGB7) mRNA is detected in multiple myeloma (MM) cells and its presence is correlated with MAF gene activation. Although the involvement of several integrin family members in MM-stoma cell interaction is well documented, the specific biologic functions regulated by integrin-β7 in MM are largely unknown. Clinically, we have correlated integrin-β7 expression in MM with poor survival outcomes post autologous stem cell transplantation and postsalvage therapy with bortezomib. Functionally, we have found that shRNA-mediated silencing of ITGB7 reduces MM-cell adhesion to extracellular matrix elements (fibronectin, E-cadherin) and reverses cell-adhesion- mediated drug resistance (CAM-DR) sensitizing them to bortezomib and melphalan. In addition, ITGB7 silencing abrogated MM-cell transwell migration in response to SDF1α gradients, reduced vessel density in xenografted tumors, and altered MM cells in vivo homing into the BM. Mechanistically, ITGB7 knockdown inhibited focal adhesion kinase (FAK) and Src phosphorylation, Rac1 activation, and SUMOylation, reduced VEGF production in MM-BM stem cell cocultures and attenuated p65-NF-κB activity. Our findings support a role for integrin-β7 in MM-cell adhesion, migration, and BM homing, and pave the way for a novel therapeutic approach targeting this molecule.
AB - Integrin-β7 (ITGB7) mRNA is detected in multiple myeloma (MM) cells and its presence is correlated with MAF gene activation. Although the involvement of several integrin family members in MM-stoma cell interaction is well documented, the specific biologic functions regulated by integrin-β7 in MM are largely unknown. Clinically, we have correlated integrin-β7 expression in MM with poor survival outcomes post autologous stem cell transplantation and postsalvage therapy with bortezomib. Functionally, we have found that shRNA-mediated silencing of ITGB7 reduces MM-cell adhesion to extracellular matrix elements (fibronectin, E-cadherin) and reverses cell-adhesion- mediated drug resistance (CAM-DR) sensitizing them to bortezomib and melphalan. In addition, ITGB7 silencing abrogated MM-cell transwell migration in response to SDF1α gradients, reduced vessel density in xenografted tumors, and altered MM cells in vivo homing into the BM. Mechanistically, ITGB7 knockdown inhibited focal adhesion kinase (FAK) and Src phosphorylation, Rac1 activation, and SUMOylation, reduced VEGF production in MM-BM stem cell cocultures and attenuated p65-NF-κB activity. Our findings support a role for integrin-β7 in MM-cell adhesion, migration, and BM homing, and pave the way for a novel therapeutic approach targeting this molecule.
UR - http://www.scopus.com/inward/record.url?scp=79959417349&partnerID=8YFLogxK
U2 - 10.1182/blood-2010-06-292243
DO - 10.1182/blood-2010-06-292243
M3 - Article
C2 - 21474670
AN - SCOPUS:79959417349
SN - 0006-4971
VL - 117
SP - 6202
EP - 6213
JO - Blood
JF - Blood
IS - 23
ER -