The Observatoire en Ville des Plaies ExSudatives (VIPES) study: insight into the patient characteristics, epidemiology, previous management, and features of wounds treated in the French community setting.

BACKGROUND: Wounds that become complex and hard-to-heal are a challenge for all health care systems. Identifying and understanding the nature of these wounds is necessary to allow appropriate intervention. OBJECTIVE: To present the epidemiological outcomes of the VIPES study. MATERIALS AND METHODS: The prospective, observational VIPES study aimed to describe the use and investigate the performance of 2 wound dressings-a silicone foam and a gelling fiber-in the management of chronic and acute wounds in a community setting in France. RESULTS: Of 407 patients recorded, 285 were included in the analysis. The 184 chronic wounds included ulcers (venous/arterial/mixed, diabetic foot, and pressure) and malignant wounds. The 101 acute wounds included surgical and traumatic wounds. Of all wounds, 98.2% were exuding and 77.9% showed exudate pooling. Unhealthy wound edges and periwound skin were reported in 57.2% and 35.4% of wounds, respectively. Of all wounds, 78.6% were in treatment failure (poor exudate management or stagnant wound). The silicone foam dressing (n = 86) and the gelling fiber (n = 199) were generally used in wounds with low or moderate exudation, or moderate or high exudation, respectively. CONCLUSIONS: The VIPES study highlights that wounds can be complex and that community care practices in France warrant improvement. Practical and up-to-date wound management recommendations are needed.

Interleukin-18 produced by bone marrow-derived stromal cells supports T-cell acute leukaemia progression.

Development of novel therapies is critical for T-cell acute leukaemia (T-ALL). Here, we investigated the effect of inhibiting the MAPK/MEK/ERK pathway on T-ALL cell growth. Unexpectedly, MEK inhibitors (MEKi) enhanced growth of 70% of human T-ALL cell samples cultured on stromal cells independently of NOTCH activation and maintained their ability to propagate in vivo. Similar results were obtained when T-ALL cells were cultured with ERK1/2-knockdown stromal cells or with conditioned medium from MEKi-treated stromal cells. Microarray analysis identified interleukin 18 (IL-18) as transcriptionally up-regulated in MEKi-treated MS5 cells. Recombinant IL-18 promoted T-ALL growth in vitro, whereas the loss of function of IL-18 receptor in T-ALL blast cells decreased blast proliferation in vitro and in NSG mice. The NFKB pathway that is downstream to IL-18R was activated by IL-18 in blast cells. IL-18 circulating levels were increased in T-ALL-xenografted mice and also in T-ALL patients in comparison with controls. This study uncovers a novel role of the pro-inflammatory cytokine IL-18 and outlines the microenvironment involvement in human T-ALL development.

NKX3.1 is a direct TAL1 target gene that mediates proliferation of TAL1-expressing human T cell acute lymphoblastic leukemia.

TAL1 (also known as SCL) is expressed in >40% of human T cell acute lymphoblastic leukemias (T-ALLs). TAL1 encodes a basic helix-loop-helix transcription factor that can interfere with the transcriptional activity of E2A and HEB during T cell leukemogenesis; however, the oncogenic pathways directly activated by TAL1 are not characterized. In this study, we show that, in human TAL1-expressing T-ALL cell lines, TAL1 directly activates NKX3.1, a tumor suppressor gene required for prostate stem cell maintenance. In human T-ALL cell lines, NKX3.1 gene activation is mediated by a TAL1-LMO-Ldb1 complex that is recruited by GATA-3 bound to an NKX3.1 gene promoter regulatory sequence. TAL1-induced NKX3.1 activation is associated with suppression of HP1-α (heterochromatin protein 1 α) binding and opening of chromatin on the NKX3.1 gene promoter. NKX3.1 is necessary for T-ALL proliferation, can partially restore proliferation in TAL1 knockdown cells, and directly regulates miR-17-92. In primary human TAL1-expressing leukemic cells, the NKX3.1 gene is expressed independently of the Notch pathway, and its inactivation impairs proliferation. Finally, TAL1 or NKX3.1 knockdown abrogates the ability of human T-ALL cells to efficiently induce leukemia development in mice. These results suggest that tumor suppressor or oncogenic activity of NKX3.1 depends on tissue expression.

Acute T-cell leukemias remain dependent on Notch signaling despite PTEN and INK4A/ARF loss.

NOTCH1 is activated by mutation in more than 50% of human T-cell acute lymphoblastic leukemias (T-ALLs) and inhibition of Notch signaling causes cell-cycle/growth arrest, providing rationale for NOTCH1 as a therapeutic target. The tumor suppressor phosphatase and tensin homolog (PTEN) is also mutated or lost in up to 20% of cases. It was recently observed among human T-ALL cell lines that PTEN loss correlated with resistance to Notch inhibition, raising concern that patients with PTEN-negative disease may fail Notch inhibitor therapy. As these studies were limited to established cell lines, we addressed this issue using a genetically defined mouse retroviral transduction/bone marrow transplantation model and observed primary murine leukemias to remain dependent on NOTCH1 signaling despite Pten loss, with or without additional deletion of p16(Ink4a)/p19(Arf). We also examined 13 primary human T-ALL samples obtained at diagnosis and found no correlation between PTEN status and resistance to Notch inhibition. Furthermore, we noted in the mouse model that Pten loss accelerated disease onset and produced multiclonal tumors, suggesting NOTCH1 activation and Pten loss may collaborate in leukemia induction. Thus, in contrast to previous findings with established cell lines, these results indicate PTEN loss does not relieve primary T-ALL cells of their "addiction" to Notch signaling.

NOTCH is a key regulator of human T-cell acute leukemia initiating cell activity.

Understanding the pathways that regulate the human T-cell acute lymphoblastic leukemia (T-ALL) initiating cells (T-LiC) activity has been hampered by the lack of biologic assays in which this human disease can be studied. Here we show that coculture of primary human T-ALL with a mouse stromal cell line expressing the NOTCH ligand delta-like-1 (DL1) reproducibly allowed maintenance of T-LiC and long-term growth of blast cells. Human T-ALL mutated or not on the NOTCH receptor required sustained activation of the NOTCH pathway via receptor/ligand interaction for growth and T-LiC activity. On the reverse, inhibition of the NOTCH pathway during primary cultures abolished in vitro cell growth and in vivo T-LiC activity. Altogether, these results demonstrate the major role of the NOTCH pathway activation in human T-ALL development and in the maintenance of leukemia-initiating cells.

Impairment of granulo-monocytic development of human common myeloid progenitors but not of granulo-monocytic progenitors by decreasing stem cell leukemia/T-cell acute leukemia 1 expression.

We recently showed that Stem Cell Leukemia/T-cell Acute Leukemia 1 (SCL/TAL1) regulates hematopoiesis from hematopoietic stem cells to committed myeloid progenitors compartment. However, in this heterogeneous compartment, the precise role of TAL1, that is largely debated, remains to be clearly defined, notably at the common myeloid progenitor (CMP) and granulo-monocytic progenitor (GMP) levels. Using small hairpin (sh)RNA lentiviral constructs, we decreased TAL1 expression in sorted human CMP and GMP subpopulations that were then assayed for erythroid and granulo-monocytic (GM) differentiation. Decreased TAL1 expression in CMP resulted in rare erythroid colonies, in a 2-3 fold reduction of GM colony number in clonogenic assays and in a 3.6-5.6 decreased production of CD14(+)CD15(+) GM cells in liquid culture. Moreover, analysis of transcript profile of gene involved in GM differentiation showed that GM cells expressing shRNA-TAL1 construct displayed decreased levels of g-csfr, c/ebpalpha, and mpo and high levels of gata-2 transcripts, indicating a blocking of GM differentiation. In contrast, GM differentiation of GMP remained unaffected when TAL1 transcript levels were decreased. These data definitively delineate the human myeloid progenitors that are regulated by TAL1. Disclosure of potential conflicts of interest is found at the end of this article.

TPM3-ALK expression induces changes in cytoskeleton organisation and confers higher metastatic capacities than other ALK fusion proteins.

Translocations of the anaplastic lymphoma kinase (ALK) gene result in the production of a number of oncogenic ALK fusion proteins implicated in tumour development. We have previously shown that X-ALK fusion proteins have differential effects on the proliferation, transformation, and invasion properties of NIH3T3 cells in vitro. In the present study, we have investigated the metastatic potential of various X-ALK expressing cell lines using an experimental lung metastasis assay. We have shown that TPM3-ALK expression bestows higher metastatic capacities than other X-ALK fusion proteins and in addition, that TPM3-ALK fusion protein expression specifically induces changes in cell morphology and cytoskeleton organisation. Co-immunoprecipitation studies demonstrate a specific interaction between TPM3-ALK and endogenous tropomyosin. Together the specific actions of TPM3-ALK on the cytoskeleton organisation offer an interesting hypothesis with respect to the higher cell motility and metastatic potential of this fusion protein.

A "liaison dangereuse" between AUF1/hnRNPD and the oncogenic tyrosine kinase NPM-ALK.

Nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) is a chimeric protein expressed in a subset of cases of anaplastic large cell lymphoma (ALCL) for which constitutive expression represents a key oncogenic event. The ALK signaling pathway is complex and probably involves functional redundancy between various signaling substrates of ALK. Despite numerous studies on signaling mediators, the molecular mechanisms contributing to the distinct oncogenic features of NPM-ALK remain incompletely understood. The search for additional interacting partners of NPM-ALK led to the discovery of AUF1/hnRNPD, a protein implicated in AU-rich element (ARE)-directed mRNA decay. AUF1 was immunoprecipitated with ALK both in ALCL-derived cells and in NIH3T3 cells stably expressing NPM-ALK or other X-ALK fusion proteins. AUF1 and NPM-ALK were found concentrated in the same cytoplasmic foci, whose formation required NPM-ALK tyrosine kinase activity. AUF1 was phosphorylated by ALK in vitro and was hyperphosphorylated in NPM-ALK-expressing cells. Its hyperphosphorylation was correlated with increased stability of several AUF1 target mRNAs encoding key regulators of cell proliferation and with increased cell survival after transcriptional arrest. Thus, AUF1 could function in a novel pathway mediating the oncogenic effects of NPM-ALK. Our data establish an important link between oncogenic kinases and mRNA turnover, which could constitute a critical aspect of tumorigenesis.

Low SCL/TAL1 expression reveals its major role in adult hematopoietic myeloid progenitors and stem cells.

Stem cell leukemia/T cell acute leukemia 1 (SCL/TAL1) plays a key role in the development of murine primitive hematopoiesis but its functions in adult definitive hematopoiesis are still unclear. Using lentiviral delivery of TAL1-directed shRNA in human hematopoietic cells, we show that decreased expression of TAL1 induced major disorders at different levels of adult hematopoietic cell development. Erythroid and myeloid cell production in cultures was dramatically decreased in TAL1-directed shRNA-expressing cells, whereas lymphoid B-cell development was normal. These results confirm the role of TAL1 in the erythroid compartment and show TLA1's implication in the function of myeloid committed progenitors. Moreover, long-term cultures and transplantation of TAL1-directed shRNA-expressing CD34+ cells into irradiated nonobese diabetic-severe combined immunodeficient (NOD-SCID) mice led to dramatically low levels of human cells of all lineages including the B-lymphoid lineage, strongly suggesting that TAL1 has a role in the early commitment of hematopoietic stem cells (HSCs) in humans. Cultures and transplantation experiments performed with mouse Sca1+ cells gave identical results. Altogether, these observations definitively show that TAL1 participates in the regulation of hematopoiesis from HSCs to myeloid progenitors, and pinpoint TAL1 as a master protein of human and murine adult hematopoiesis.

Gene expression profiling in anaplastic large cell lymphoma and Hodgkin's disease.

Recent efforts have been made to isolate molecular targets that could explain different outcome between histological subtypes of lymphomas and to understand the molecular mechanisms underlying oncogenic events. Using the SSH technique, we compared the transcriptome of 2 cases of ALK+ and ALK- anaplastic large cell lymphoma (ALCL) and of 2 cases of classical Hodgkin's lymphoma (cHL) with opposite behavior. Regarding ALCL, we showed that ALK-positive tumors overexpressed genes involved in different signaling pathways such as activation or signaling of T-cells, regulation of apoptosis, phospholipase Cgamma and phosphatidyl inositol-3 Kinase. In addition, the characterization of a specific molecular signature may be of clinical relevance since ALK+ tumors generally have a better prognosis than ALK- ones. Similar problems of differential prognosis is observed in cases of cHL, which in addition, may be morphologically and immunologically indistinguishable. Therefore, we applied the same SSH technique to 2 cHL samples from patients with favorable and poor outcome, respectively. Forty-four cDNAs were significantly overexpressed in the poor outcome case. In addition to the defender against death cell 1 (DAD1) gene, overexpressed clones corresponded mostly to expressed sequence tags (ESTs). Interestingly, the present study identifies new genes which may be involved in the pathogenesis and/or clinical outcome of cHL and deserve further investigations.

Differential effects of X-ALK fusion proteins on proliferation, transformation, and invasion properties of NIH3T3 cells.

Majority of anaplastic large-cell lymphomas (ALCLs) are associated with the t(2;5)(p23;q35) translocation, fusing the NPM (nucleophosmin) and ALK (anaplastic lymphoma kinase) genes (NPM-ALK). Recent studies demonstrated that ALK may also be involved in variant translocations, namely, t(1;2)(q25;p23), t(2;3)(p23;q21), t(2;17)(p23;q23) and inv(2)(p23q35), which create the TPM3-ALK, TFG-ALK5, CLTC-ALK, and ATIC-ALK fusion genes, respectively. Although overexpression of NPM-ALK has previously been shown to transform fibroblasts, the transforming potential of variant X-ALK proteins has not been precisely investigated. We stably transfected the cDNAs coding for NPM-ALK, TPM3-ALK, TFG-ALK, CLTC-ALK or ATIC-ALK into nonmalignant NIH3T3 cells. All X-ALK variants are tyrosine phosphorylated and their subcellular distribution was in agreement with that observed in tumors. Moreover, our results show that the in vitro transforming capacity of NIH3T3-transfected cells are in relation to the level of X-ALK fusion proteins excepted for TPM3-ALK for which there is an inverse correlation. The differences between the five X-ALK variants with regard to proliferation rate, colony formation in soft agar, invasion, migration through the endothelial barrier and tumorigenicity seem to be due to differential activation of various signaling pathways such as PI3-kinase/AKT. These findings may have clinical implications in the pathogenesis and prognosis of ALK-positive ALCLs.

Chronic myeloproliferative disorders with rearrangement of the platelet-derived growth factor alpha receptor: a new clinical target for STI571/Glivec.

Two cases of atypical chronic myeloid leukaemia (CML) carrying the t(4;22)(q12;q11) translocation involving the breakpoint cluster region (BCR) and platelet-derived growth factor alpha receptor (PDGFRA) genes have been recently characterized. We report a third case of atypical CML with the same translocation but with a distinct breakpoint fusing BCR exon 1 with PDGFRA exon 13. The patient had a clinical presentation of CML with progressive transformation in B-cell acute lymphoblastic leukaemia. The involvement of PDGFRA led us to treat the patient with the small organic compound imatinib mesylate/STI571 (Glivec) that blocks the ATP binding site of tyrosine kinases such as Abelson, KIT and platelet-derived growth factor receptors. The patient subsequently achieved a rapid clinical and molecular response clearly demonstrating, for the first time, that Glivec is active against PDGFRA in vivo. Therefore, our study expands the list of Glivec targets and has direct biological and also clinical implications.

Non-muscle myosin heavy chain (MYH9): a new partner fused to ALK in anaplastic large cell lymphoma.

In anaplastic large cell lymphoma, the ALK gene at 2p23 is known to be fused to NPM, TPM3, TPM4, TFG, ATIC, CLTC, MSN, and ALO17. All of these translocations result in the expression of chimeric ALK transcripts that are translated into fusion proteins with tyrosine kinase activity and oncogenic properties. We report a case showing a restricted cytoplasmic staining pattern of ALK and a novel chromosomal abnormality, t(2;22)(p23;q11.2), demonstrated by fluorescence in situ hybridization analysis. The result of 5' RACE analysis showed that the ALK gene was fused in-frame to a portion of the non-muscle myosin heavy chain gene, MYH9. Nucleotide sequence of the MYH9-ALK chimeric cDNA revealed that the ALK breakpoint was different from all those previously reported. It is localized in the same exonic sequence as MSN-ALK, but 6 bp downstream, resulting in an in-frame fusion of the two partner proteins. In contrast to the previously reported ALK fusion proteins, MYH9-ALK may lack a functional oligomerization domain. However, biochemical analysis showed that the new fusion protein is tyrosine phosphorylated in vivo but seems to lack tyrosine kinase activity in vitro. If further investigations confirm this latter result, the in vivo tyrosine phosphorylation of MYH9-ALK protein could involve mechanisms different from those described in the other ALK hybrid proteins.