Differential MMP and TIMP production by human marrow and peripheral blood CD34+ cells in response to chemokines

Beyond tumorigenesis: cancer stem cells in metastasis

“…Similarly, stromal cell derived factor and its receptor CXCR4 form a critical regulatory axis for HSC migration, engraftment and homing [88][89][90][91][92], and also function in the metastasis of breast, prostate and other types of cancer [73,[93][94][95][96][97][98][99][100]. Matrix metalloproteinase-9 (MMP-9), belongs to a family of MMPs that plays a critical role during cancer cell invasion [101][102][103][104], and it is also involved in HSC homing and migration [105][106][107]. In addition to providing niches for HSCs, skeletal bones are also the most common sites for cancer metastasis [108].…”

The possible role of matrix metalloproteinase (MMP)-2 and MMP-9 in cancer, e.g. acute leukemia

“…Variable expression levels of MMP-2 and -9 could be detected in conditioned media of myeloid cell lines [177][178][179][180][181][182][183]. The capability of penetrating matrigel in an invasion assay by KG-1 could be partially blocked by TIMP-2 and an MMP-2 antibody, but not by an MMP-9 antibody, indicating that in vitro invasion largely depends on MMP-2 activity [181].…”

“…Moreover, normal CD34 + bone marrow mononuclear cells are capable of expressing MMP-9, with an adequate stimulus [61,179,[186][187][188]. Some articles have suggested that MMP-9 expression might be involved in physiological processes, e.g.…”

“…So far, it is known that leukemic cells are capable of expressing MMP-2 and/or -9. Many studies show a reflection of MMP-2 and/or -9 with invasive behavior in ALL and AML cell lines [15,[174][175][176][177][178][179][180]184,187]. No MMP-2 expression can be detected in normal bone marrow mononuclear cells.…”

Homing of Cancer Cells to the Bone

“…MMP-12 increases the invasive capacity of PC3 cells by degradation of type 1 collagen [42]. Interestingly SDF-1 mediated secretion of MMP-2 and MMP-9 by CD34 + progenitor stem cells facilitates in vitro migration of these cells towards SDF-1 [43].…”