Membrane Type-1 Matrix Metalloproteinase Expression in Acute Myeloid Leukemia and Its Upregulation by Tumor Necrosis Factor-α

Expression and Activity of Matrix Metalloproteinases in Leukemia

Matrix metalloproteinases (MMPs) are responsible for the degradation of extracellular matrix components and hence play a crucial role in physiological and pathologic processes. The imbalance between the expression of MMPs and their inhibitors can be effective in leukemic cell processes such as migration, angiogenesis, survival, and apoptosis, playing a key role in the progression and prognosis of leukemia. In this review, we discuss the potential involvement of MMPs and their inhibitors in the pathogenesis and progression of leukemia by examining their role in the prognosis of leukemia. Inducing leukemic cell growth, migration, invasiveness, and angiogenesis are the main roles of MMPs in leukemia progression mediated by their degradative activity. Given the important role of MMPs in leukemia progression, further clinical trials are needed to confirm the link between MMPs' expressions and leukemia prognosis. It is hoped to use MMPs as therapeutic targets to improve patients' health by recognizing the prognostic value of MMPs in leukemia and their effect on the progression of these malignancies and their response to treatment.

Increased phosphorylation of eIF2α in chronic myeloid leukemia cells stimulates secretion of matrix modifying enzymes

Recent studies underscore the role of the microenvironment in therapy resistance of chronic myeloid leukemia (CML) cells and leukemia progression. We previously showed that sustained mild activation of endoplasmic reticulum (ER) stress in CML cells supports their survival and resistance to chemotherapy. We now demonstrate, using dominant negative non-phosphorylable mutant of eukaryotic initiation factor 2 α subunit (eIF2α), that phosphorylation of eIF2α (eIF2α-P), which is a hallmark of ER stress in CML cells, substantially enhances their invasive potential and modifies their ability to secrete extracellular components, including the matrix-modifying enzymes cathepsins and matrix metalloproteinases. These changes are dependent on the induction of activating transcription factor-4 (ATF4) and facilitate extracellular matrix degradation by CML cells. Conditioned media from CML cells with constitutive activation of the eIF2α-P/ATF4 pathway induces invasiveness of bone marrow stromal fibroblasts, suggesting that eIF2α-P may be important for extracellular matrix remodeling and thus leukemia cells-stroma interactions. Our data show that activation of stress response in CML cells may contribute to the disruption of bone marrow niche components by cancer cells and in this way support CML progression.

Tumor necrosis factor α in the onset and progression of leukemia

Tumor necrosis factor alpha (TNF-α), originally described as an anti-neoplastic cytokine, has been found, in apparent contradiction to its name, to play an important role in promoting the development and progression of malignant disease. Targeting TNF-α with TNF antagonists has elicited an objective response in certain solid tumors in phase I and II clinical trials. This review focuses on the relationship of TNF-α expressed by leukemia cells and adverse clinical features of leukemia. TNF-α is involved in all steps of leukemogenesis, including cellular transformation, proliferation, angiogenesis, and extramedullary infiltration. TNF-α is also an important factor in the tumor microenvironment and assists leukemia cells in immune evasion, survival, and resistance to chemotherapy. TNF-α may be a potent target for leukemia therapy.

[Influence of immunocorrection on the inflammatory process in the urogenital tract in men with infertility]

We studied the concentration of metalloproteinases, pro-and anti-inflammatory cytokines, lymphocyte activation markers in seminal plasma of men with oligosymptomatic forms of chronic inflammation of the urogenital tract complicated with infertility. It was shown that chronic inflammation of the urogenital tract shifts the levels of cytokine profile, reduces the concentration of metalloproteinase-2 (576.4 +/- 89.3 ng/ml, P < 0.001), chemokines - fractalkine (16.3 +/- 1.3 pg/ml, P < 0.001) and chemmmokine regulated by activation, expression and secretion of normal T-cells (RANTES (12.7 +/- 1.0 pg/ ml, P < 0.001). Additionally, we observed a sharp increase in IL-8 (215.5 +/- 7.8 pg/ml, P < 0.01), MCP-1 (926.4 +/- 30.2 pg/ml, P < 0.001) and elevation of the CD25 + / CD95 + ratio. These observations point for alterations in apoptotic mechanisms in pathological forms of the generative cells and their accumulation in the sperm. Prolonged inflammation of the genital area is accompanied by depletion of the local immune system resulting in the development of infertility. The multidirectional shifts in IL-10/IL-12 index have been established: an increase in the group of patients with elevated level of hypercapitated spermatozoa and its reduction in microsomatic morphotype of spermatozoa. These data emphasize the importance of the microenvironment in maturation of gametes. It was shown that an inclusion of alfagin and gepatomax in immunorehabilitation of men with oligosymptomatic forms of urogenital infections improves leukocyte subpopulation content of sperm and concentrations of pro-and anti-inflammatory cytokines, and therefore, results in an increase in fertilizing potential.