Nuclear Translocation of PKC is Associated with Cell Cycle Arrest and Erythroid Differentiation in Myelodysplastic Syndromes (MDSs)

PI-PLC beta 1 is involved in cell proliferation, differentiation, and myelodysplastic syndrome (MDS) pathogenesis. Moreover, the increased activity of PI-PLC beta 1 reduces the expression of PKC-alpha, which, in turn, delays the cell proliferation and is linked to erythropoiesis. Lenalidomide is currently used in low-risk patients with MDS and del(5q), where it can suppress the del(5q) clone and restore normal erythropoiesis. In this study, we analyzed the effect of lenalidomide on 16 patients with low-risk del(5q) MDS, as well as del(5q) and non-del(5q) hematopoietic cell lines, mainly focusing on erythropoiesis, cell cycle, and PI-PLC beta 1/PKC-alpha signaling. Overall, 11 patients were evaluated clinically, and 10 (90%) had favorable responses; the remaining case had a stable disease. At a molecular level, both responder patients and del(5q) cells showed a specific induction of erythropoiesis, with a reduced gamma/beta-globin ratio, an increase in glycophorin A, and a nuclear translocation of PKC-alpha. Moreover, lenalidomide could induce a selective G(0)/G(1) arrest of the cell cycle in del(5q) cells, slowing down the rate proliferation in those cells. Altogether, our results could not only better explain the role of PI-PLC beta 1/PKC-alpha signaling in erythropoiesis but also lead to a better comprehension of the lenalidomide effect on del(5q) MDS and pave the way to innovative, targeted therapies

TIME- AND DOSE-DEPENDENT EFFECTS OF CHRONIC WOUND FLUID ON HUMAN ADULT DERMAL FIBROBLASTS

BACKGROUND Wound healing is a biologic process that is altered in patients affected by chronic venous ulcers. The wound microenvironment is reflected in the chronic wound fluid (CWF), an exudate containing serum components and tissue-derived proteins. OBJECTIVES We investigated the effects of increasing doses of CWF collected from patients suffering from chronic venous ulcers on human adult dermal fibroblasts cultured in vitro and the relationship among CWF effects and treatment length. METHODS Fibroblasts were treated with 60, 240, and 720 mg/mL CWF for 3 and 7 days. We evaluated cell proliferation and viability by MTT and Trypan blue assay, cell morphology by light microscopy, F-actin microfilaments organization by tetramethylrhodamine B isothiocyanate-conjugated phalloidin, a-smooth muscle actin expression by immunofluorescence, and senescence-associated b-galactosidase activity. RESULTS CWF induced an increase in cell proliferation in the first 3 days of treatment. In contrast, at 7 days, a strong decrease in cell viability was observed. These changes were related to a cytoskeletal F-actin reorganization and not to fibroblast-myofibroblast differentiation nor to changes in cellular senescence. CONCLUSIONS This study shows a dose-dependent and biphasic effect of CWF on dermal fibroblasts, suggesting that a continuous exposure to chronic wounds microenvironment may induce late cellular dysfunctions possibly involved in the delayed wound healing

Gene polymorphisms in folate metabolizing enzymes in adult acute lymphoblastic leukemia: effects on methotrexate-related toxicity and survival

Individual variations in response and/or toxicity to anti-cancer agents is common. The antifolate agent methotrexate is frequently used in maintenace therapy of acute lymphoblastic leukemia. The findings of this study suggest that genotyping of folate polymorphisms might be useful in adult acute lymphoblastic leukemia to optimize methotrexate therapy, reducing the associated toxicity with possible effects on survival

Obesity Shapes Metabolism in the Tumor Microenvironment to Suppress Anti-Tumor Immunity

Obesity is a major cancer risk factor, but how differences in systemic metabolism change the tumor microenvironment (TME) and impact anti-tumor immunity is not understood. Here, we demonstrate that high-fat diet (HFD)-induced obesity impairs CD8(+) T cell function in the murine TME, accelerating tumor growth. We generate a single-cell resolution atlas of cellular metabolism in the TME, detailing how it changes with diet-induced obesity. We find that tumor and CD8(+) T cells display distinct metabolic adaptations to obesity. Tumor cells increase fat uptake with HFD, whereas tumor-infiltrating CD8(+) T cells do not. These differential adaptations lead to altered fatty acid partitioning in HFD tumors, impairing CD8(+) T cell infiltration and function. Blocking metabolic reprogramming by tumor cells in obese mice improves anti-tumor immunity. Analysis of human cancers reveals similar transcriptional changes in CD8(+) T cell markers, suggesting interventions that exploit metabolism to improve cancer immunotherapy