The expression of VEGFA, VEGF receptor (VEGFR), matrix metalloproteinase (MMP)-2, MMP-9, Delta-like ligand 4 (DLL4) and Integrin-5 was significantly reduced in TNBC tumor tissues.
Finally, we found that MDSCs secrete prometastatic factors such as MMP9 and chitinase 3-like 1 to promote TNBC cancer stem cell function, thereby identifying a nonimmunologic role for MDSCs in promoting TNBC progression.
In summary, inhibition of Src kinase suppressed TNBC tumor growth and metastasis, and Src inhibitors such as BJ-2302 may constitute a novel therapeutic tool to treat breast cancer that expresses high levels of CTSS and MMP-9.
We measured CD68, CD163, and MMP-9 protein expression in formalin-fixed paraffin-embedded tissues of breast carcinomas represented in tissue microarray format using multiplexed quantitative immunofluorescence (QIF) in two independent Yale cohorts: cohort A-n = 398, estrogen receptor-positive (ER<sup>+</sup>) and ER<sup>-</sup> cases-and the triple-negative breast cancer (TNBC)-only cohort B (n = 160).
Up-regulation of miR-206 in TNBC contributed to a decreasing metastatic potential, as demonstrated by a reduction of cell viability and proliferation, decreased cell migration and invasion, lower expression levels of matrix metalloproteinase (MMP)-2, MMP-9 and a higher expression level of breast cancer metastatic suppressor (BRMS)-1.