The effect of FK506 on transforming growth factor beta signaling and apoptosis in chronic lymphocytic leukemia B cells.

Background Loss of response to transforming growth factor-beta (TGF-beta) is thought to contribute to the progression of chronic lymphocytic leukemia. Recent findings of over-activation of the TGF-beta signal in FKBP12-knockout mouse prompted us to investigate whether FK506, the canonical ligand of FKBP, can activate the TGF-beta signal in chronic lymphocytic leukemia. Design and Methods We studied 62 chronic lymphocytic leukemia samples from patients with Rai/Binet stage 0 to 4 disease. The TGF-beta signal was investigated by western blotting and flow cytometry. The levels of Bcl2-family members and death-associated-protein kinase were also investigated by western blotting, whereas apoptosis was studied in flow cytometry. Down-modulation of FKBP12 was obtained by gene silencing with short interfering RNA. Results Twenty-two out of 62 chronic lymphocytic leukemia samples were sensitive to TGF-beta-induced apoptosis. All but two of the responsive samples underwent apoptosis also when cultured with FK506, but not with cyclosporine. Thirteen samples that were not sensitive to TGF-beta were sensitive to FK506. Overall, response to FK506 occurred in 33 samples. FK506 induced Smad2 phosphorylation and nuclear translocation. Accordingly, death-associated-protein kinase, a transcriptional target of Smad, was induced. At the same time, Bcl-2 and Bcl-xL levels decreased whereas the levels of Bim and Bmf increased. A loss of mitochondrial membrane potential preceded caspase activation and cell death. FK506 removed FKBP12 from its binding to the TGF-beta-receptor. FKBP12 release activated the receptor-kinase activity as suggested by the enhanced levels of phospho-Smad found in cells depleted of FKBP12. Conclusions Our study shows that most chronic lymphocytic leukemia cells escape the homeostatic control of TGF-beta and that FK506 restores the TGF-beta signal in a proportion of non-responsive samples. We demonstrated that FK506 activates TGF-beta receptor I kinase activity in chronic lymphocytic leukemia, which transduces apoptosis by a mitochondrial-dependent pathway

A Frontline Approach With Peripherally Inserted Versus Centrally Inserted Central Venous Catheters for Remission Induction Chemotherapy Phase of Acute Myeloid Leukemia: A Randomized Comparison

BACKGROUND: The incidence of peripherally inserted central catheter (PICC)-related adverse events has been uncertain in the setting of acute myeloid leukemia (AML) compared with the incidence of centrally inserted central catheter (CICC) adverse events. PATIENTS AND METHODS: We conducted a monocentric, randomized trial of patients with previously untreated AML. Of the 93 patients, 46 had received a PICC and 47 had received a CICC as frontline intravascular device. Thereafter, all patients underwent intensive chemotherapy for hematologic remission induction. The primary endpoint was catheter-related (CR)-bloodstream infection (BSI) and venous thrombosis (VT) rate. The secondary endpoints catheter malfunction, catheter removal, and patient overall survival. RESULTS: The CR-BSI and CR-VT rate in the PICC and CICC groups was 13% and 49%, respectively, with a difference of 36 percentage points (relative risk for CR-BSI or CR-VT, 0.266; P = .0003). The CR-BSI incidence was 1.4 and 7.8 per 1000 catheters daily in the PICC and CICC groups, respectively. Among the CR thromboses, the symptomatic VT rate was 2.1% in the PICC group and 10.6% in the CICC group. In the CICC group, 16 of the 47 patients (34%) had the catheter removed for BSI (n = 5), septic thrombophlebitis (n = 4), VT (n = 2), or malfunction (n = 5) a median of 7 days after insertion. In the PICC group, only 6 of the 46 patients (13%) required catheter removal for VT (n = 2) or malfunction (n = 4). At a median follow-up of 30 days, 6 patients in the CICC group died of CR complications versus none of the patients in the PICC group (P = .012). Using PICCs, the reduction in BSI and symptomatic VT decreased mortality from CR infection and venous thromboembolism. In contrast, the CICC approach led to early catheter removal mostly for difficult-to-treat infectious pathogens. CONCLUSION: Our data have confirmed that BSI and symptomatic VT are the major complications affecting frontline central intravascular device-related morbidity in the leukemia setting. The use of a PICC is safer than that of a CICC and maintains the effectiveness for patients with AML undergoing chemotherapy, with an approximate fourfold lower combined risk of infection or thrombosis at 30 days

Adaptive and Innate Cytotoxic Effectors in Chronic Lymphocytic Leukaemia (CLL) Subjects with Stable Disease

Chronic lymphocytic leukaemia (CLL) is characterised by the expansion of a neoplastic mature B cell clone. CLL clinical outcome is very heterogeneous, with some subjects never requiring therapy and some showing an aggressive disease. Genetic and epigenetic alterations and pro-inflammatory microenvironment influence CLL progression and prognosis. The involvement of immune-mediated mechanisms in CLL control needs to be investigated. We analyse the activation profile of innate and adaptive cytotoxic immune effectors in a cohort of 26 CLL patients with stable disease, as key elements for immune-mediated control of cancer progression. We observed an increase in CD54 expression and interferon (IFN)-γ production by cytotoxic T cells (CTL). CTL ability to recognise tumour-targets depends on human leukocyte antigens (HLA)-class I expression. We observed a decreased expression of HLA-A and HLA-BC on B cells of CLL subjects, associated with a significant reduction in intracellular calnexin that is relevant for HLA surface expression. Natural killer (NK) cells and CTL from CLL subjects show an increased expression of the activating receptor KIR2DS2 and a reduction of 3DL1 and NKG2A inhibiting molecules. Therefore, an activation profile characterises CTL and NK cells of CLL subjects with stable disease. This profile is conceivable with the functional involvement of cytotoxic effectors in CLL control

Predominant VH1-69 IgBCR Clones Show Higher Expression of CD5 in Heterogeneous Chronic Lymphocytic Leukemia Populations

The immunoglobulin B cell receptor (IgBCR) expressed by chronic lymphocytic leukemia (CLL) B cells plays a pivotal role in tumorigenesis, supporting neoplastic transformation, survival, and expansion of tumor clones. We demonstrated that in the same patient, two or more CLL clones could coexist, recognized by the expression of different variable regions of the heavy chain of IgBCR, composing the antigen-binding site. In this regard, phage display screening could be considered the easier and most advantageous methodology for the identification of small peptide molecules able to mimic the natural antigen of the tumor IgBCRs. These molecules, properly functionalized, could be used as a probe to specifically identify and isolate single CLL subpopulations, for a deeper analysis in terms of drug resistance, phenotype, and gene expression. Furthermore, CLL cells express another surface membrane receptor, the CD5, which is commonly expressed by normal T cells. Piece of evidence supports a possible contribution of CD5 to the selection and maintenance of autoreactivity in B cells and the constitutive expression of CD5 on CLL cells could induce pro-survival stimuli. In this brief research report, we describe a peptide-based single-cell sorting using as bait the IgBCR of tumor cells; in the next step, we performed a quantitative analysis of CD5 expression by qRT-PCR related to the expressed IgBCR. Our approach could open a new perspective for the identification, isolation, and investigation of all subsets of IgBCR-related CLL clones, with particular attention to the more aggressive clones

Acquired Factor V Inhibitor after Coronavirus Disease 2019 (COVID-19)

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