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Abstract: Myeloid sarcoma (MS) is defined as a tumor mass consisting of myeloid blast with or without maturation occurring at an anatomical site other than bone marrow with normal architectural effacement. It can also precede the onset of leukemia which is called non-leukemic MS. Non-leukemic MS is a kind of rare disease and easy to be misdiagnosed as other common malignancies due to the rarity and nonspecific manifestation. We herein report an unusual case of non-leukemic MS involving the vulva, vagina, and cervix in a female patient. The bone marrow aspiration and biopsy of the patient revealed no hematological abnormality. Immunohistochemical staining of the biopsies was strongly positive for myeloperoxidase, CD68, leukocyte common antigen (LCA), CD117, CD34, CD38, CD79a, and negative for cytokeratin (CK), epithelial memberane antigen (EMA), CD2, CD3, CD20, CD5, CD138. Then a diagnosis of non-leukemic MS was made. Unfortunately, our patient received only one cycle of chemotherapy consisting of cytosine arabinoside and daunorubicin, then refused any further treatment and died 4 months after diagnosis. Although systemic chemotherapy is widely accepted to be a promising strategy, its benefit still needs to be further assessed. Certain questions still need to be answered for this disease: 1) Why can approximately 20% of the patients with non-leukemic MS remain disease-free after local therapy alone? 2) How many cycles of chemotherapy are needed for these patients after achievement of complete remission? 3) What are the prognostic or risk factors in these patients who have no abnormality of karyotype, fusion genes, or gene mutation to predict responsiveness to chemotherapy and outcome? 4) What is the risk factor for relapse? The rarity of non-leukemic MS makes it almost impossible to conduct large-scale randomized trials, but judicious study for each patient with MS is helpful for a further understanding of the nature of the disease. [ABSTRACT FROM AUTHOR]

Peroxisome proliferator-activated receptor-gamma (PPAR-γ) is one of the best characterized nuclear hormone receptors (NHRs) in the superfamily of ligand-activated transcriptional factors. PPAR-γ ligands have recently been demonstrated to affect proliferation, differentiation and apoptosis of different cell types. The present study was undertaken to investigate PPAR-γ ligands induced cell growth inhibition and its influence on matrix metalloproteinase MMP-9 and MMP-2 activities on leukemia K562 and HL-60 cells in vitro. The results revealed that PPAR-γ expression was detectable in the two kinds of leukemia cells; Both 15-deoxy-delta(12,14)-prostaglandin J2(15d-PGJ2) and troglitazone (TGZ) have significant growth inhibition effects on these two kinds of leukemia cells. These two PPAR-γ ligands could inhibit the leukemic cell adhesion to the extracellular matrix (ECM) proteins and the invasion through matrigel matrix. The expressions of MMP-9 and MMP-2 as well as their gelatinolytic activities in both HL-60 and K562 cells were inhibited by 15d-PGJ2 and TGZ significantly. We therefore conclude that PPAR-γ ligands 15d-PGJ2 and TGZ have significant growth inhibition effects on myeloid leukemia cells in vitro, and that PPAR-γ ligands can inhibit K562 and HL-60 cell adhesion to and invasion through ECM as well as downregulate MMP-9 and MMP-2 expressions. The data suggest that PPAR-γ ligands may serve as potential anti-leukemia reagents. [ABSTRACT FROM AUTHOR]

The anti-proliferation effects of oridonin on acute promyelocytic leukemia (APL) cells and its mechanisms were studied in vitro. NB4 cells as well as fresh leukemia cells obtained from APL patients in culture medium were treated with different concentrations of oridonin. Cell growth inhibition, apoptosis and related pathways were assessed by MTT assay as well as flow cytometry (FCM) and western blot analysis. The data revealed that oridonin (over 16?µmol/L) could inhibit the growth of NB4 cells by induction of apoptosis. Marked changes of cell apoptosis were observed very clearly by using electron microscopy and DNA fragmentation analysis after the cells exposed to oridonin for 48?h; Western blotting showed cleavage of the caspase-3 zymogen protein (32-kDa) with the appearance of its 20-kDa subunit as well as a cleaved 89-kDa fragment of 116-kDa PARP when apoptosis occurred. The expression of Bcl-2 was down-regulated remarkably accompanied by the disruption of the mitochondrial membrane potential (??m). The anti-proliferative and apoptosis-inducing effects by oridonin in fresh APL cells were also found remarkably using Trypan Blue dye exclusion method and Wright's staining. We concluded that oridoning has significant anti-proliferative and apoptosis-inducing effects on NB4 cells by activation of caspase-3 and cleavage of PARP as well as by down regulation of Bcl-2 and disruption of the ??m. Furthermore, oridonin demonstrated apparent cell growth inhibition effects on fresh APL cells in vitro. The results indicated that oridonin may serve as a potential anti-leukemia reagent. [ABSTRACT FROM AUTHOR]