Thy-1 (CD90)-Induced Metastatic Cancer Cell Migration and Invasion Are β3 Integrin-Dependent and Involve a Ca2+/P2X7 Receptor Signaling Axis

Abstract

Cancer cell adhesion to the vascular endothelium is an important step in tumor metastasis. Thy-1 (CD90), a cell adhesion molecule expressed in activated endothelial cells, has been implicated in melanoma metastasis by binding to integrins present in cancer cells. However, the signaling pathway(s) triggered by this Thy-1-Integrin interaction in cancer cells remains to be defined. Our previously reported data indicate that Ca2+-dependent hemichannel opening, as well as the P2X7 receptor, are key players in Thy-1-αVβ3 Integrin-induced migration of reactive astrocytes. Thus, we investigated whether this signaling pathway is activated in MDA-MB-231 breast cancer cells and in B16F10 melanoma cells when stimulated with Thy-1. In both cancer cell types, Thy-1 induced a rapid increase in intracellular Ca2+, ATP release, as well as cell migration and invasion. Connexin and Pannexin inhibitors decreased cell migration, implicating a requirement for hemichannel opening in Thy-1-induced cell migration. In addition, cell migration and invasion were precluded when the P2X7 receptor was pharmacologically blocked. Moreover, the ability of breast cancer and melanoma cells to transmigrate through an activated endothelial monolayer was significantly decreased when the β3 Integrin was silenced in these cancer cells. Importantly, melanoma cells with silenced β3 Integrin were unable to metastasize to the lung in a preclinical mouse model. Thus, our results suggest that the Ca2+/hemichannel/ATP/P2X7 receptor-signaling axis triggered by the Thy-1-αVβ3 Integrin interaction is important for cancer cell migration, invasion and transvasation. These findings open up the possibility of therapeutically targeting the Thy-1-Integrin signaling pathway to prevent metastasis.

An Outside-In Switch in Integrin Signaling Caused by Chemical and Mechanical Signals in Reactive Astrocytes

“…Our laboratory has described a role for Thy-1 in integrin ligation. Upon binding to integrins, Thy-1 increases integrin expression and clustering, focal adhesion and stress fiber formation, as well as cell contractility and migration of astrocytes ( Avalos et al, 2004 ; Lagos-Cabré et al, 2017 , 2018 ) and cancer cells ( Brenet et al, 2020 ). Mechanical tension generated by a stiffer ECM also drives clustering of integrins ( Cluzel et al, 2005 ).…”

Single-Cell Proteomic Profiling Identifies Nanoparticle Enhanced Therapy for Triple Negative Breast Cancer Stem Cells

“…CD90 was reported as a stem cell marker that had an association with a number of cell surface molecules that allow the formation of extra/intracellular multiprotein complexes that could promote cancer formation in various cancer cell lines [ 21 , 22 , 23 ]. CD90-α V β 3 integrin interaction is important for cancer cell migration, invasion, and transvasation [ 24 ]. β3 integrin was also reported to be required for the promotion of sphere formation and up-regulated the expression of the cancer stem cell marker CD133 by CD90 [ 25 ].…”

Pannexin Channel Regulation of Cell Migration: Focus on Immune Cells

“…Pioneer studies that revealed PANX1 interaction with the actin cytoskeleton, suggested its pro-migratory phenotype in breast cancer ( 25 ). Indeed, PANX1 promotes motility, transmigration, and in vivo invasion in melanoma, breast and testicular cancer cells: B16-BL6, B16-F10; CN34, CN-LM1A, MDA-MB-231 MDA-MB-468, MDA-LM2, and I-10 cells, respectively ( 99 , 100 , 122 , 123 ). In some cases, such as testicular cancer PANX1 activity was required for ERK1/2 activity, E-cadherin and metalloproteinase 9 (MMP-9) revealing that these channels contribute with different aspects of cell migration ( 99 ).…”

“…Like normal fibroblasts (see section above), MDA-MB-231 cells are sensitive to Thy-1 that increases cell migration by releasing ATP via PANX1 channels with subsequent activation of P2X 7 receptors in a positive feedback loop ( 123 ). Consequently, a mutation that increases the permeability of PANX1 channels leading to an exacerbated ATP release, also promotes cell motility, but not trans-endothelial migration ( 100 ), suggesting that PANX1 contributes to specific steps during tumor progression.…”