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Acute promyelocytic leukaemia is characterized by an expansion of haematopoietic precursors arrested at the promyelocytic stage (1). The differentiation block can be reversed by retinoic acid, which induces blast differentiation both in vitro (2) and in vivo (3-4). Acute promyelocytic leukaemia is also characterized by a 15;17 chromosome translocation (5) with breakpoints within the retinoic acid alpha receptor (RAR alpha) gene on 17 and within the PML gene, that encodes a putative transcription factor of unknown function (6-7), on 15 (8-10). As a consequence of the translocation a PML/RAR alpha gene is formed. It is transcriptionally active and encodes a PML/RAR alpha fusion protein detectable in all APL cases (11-14). We expressed the PML/RAR alpha protein in U937 myeloid precursor cell line and show that they: 1) lose the capacity to differentiate under the action of different stimuli (vitamin D3, transforming growth factor beta 1); ii) acquire enhanced sensitivity to retinoic acid; iii) exhibit a higher growth rate that is due to a reduction in apoptotic cell death. These results provide the first evidence of biological activity of PML/RAR alpha and recapitulate critical features of the promyelocytic leukemia phenotype.

Les echanges plasmatiques utilises conjointement avec les traitements immunosuppresseurs ont permis d'obtenir une amelioration des manifestations cutanees, articulaires, musculaires et vasculaires chez 3 patients atteint de sclerodermie de type II de Barnett: diminution de la rigidite de la peau, flexion des doigts devenue possible, disparition des arthralgies, regression des signes d'une myosite inflammatoire, diminution en frequence et intensite des manifestations des syndromes de Raynaud. Nos resultats suggerent que ce traitement combine peut prendre une place dans l'arsenal therapeutique de la sclerodermie generalisee. Les bases de l'amelioration clinique sont inconnues. Les drogues cytotoxiques pourraient eviter les phenomenes de rebond durant la periode qui suit l'arret des echanges.

From 1960 to 1984, 78 new patients with progressive systemic sclerosis were followed up: 60 women and 18 men whose ages ranged from 20 to 83 years, with a mean age of 58 years. Twenty nine are known to be dead and 3 were lost of follow-up. Forty six have been followed up to the present time for a mean period of 5 years. The cumulative survival rates were 88 +/- 7 p. 100 at one year, 62,5 +/- 11,5 p. 100 at five years and 50,5 +/- 15 p. 100 at ten years. These figures are significantly different from those found in a matched group from the French general population. Nine features at the time of diagnosis which might influence prognosis were studied. Seven factors apparently have not affected prognosis: sex, age, time elapsed between initial symptom and definitive diagnosis, location of scleroderma, blood pressure, erythrocyte sedimentation rate and creatinine clearance. On the other hand, survival declined significantly faster in the 28 patients with anemia than in the 50 patients without anemia (P less than 0,001). Similarly, the 47 patients with radiological pulmonary involvement or pulmonary function abnormalities were at significantly higher risk for death than the 31 patients without interstitial pulmonary fibrosis. Anemia and pulmonary involvement are predictors of mortality and important prognostic tools in the management of the different drugs that have been recommended for the treatment of patients with systemic sclerosis.

We have analyzed the differentiation program of a U937 promonocytic leukemia clone transduced with the acute promyelocytic leukemia specific PML/RAR alpha fusion gene, the expression of which is under the control of the inducible metallothionine (MT) I promoter (MTPR9 clone). MTPR9 cells treated with Zn2+ hence exhibit levels of PML-RAR alpha protein as high as fresh acute promyelocytic leukemia blasts. In the absence of Zn2+, i.e., upon low level PML/RAR alpha expression, 1,25-dihydroxyvitamin D3 (D3) and particularly D3 plus transforming growth factor beta 1 (TGF-beta 1) induced terminal differentiation of MTPR9 cells (as observed in "wild-type" U937 cells), on the basis of morphology, membrane antigen pattern, and functional criteria. Conversely, in the presence of Zn2+, D3 and D3 plus TGF-beta 1 failed to induce terminal differentiation, as evaluated by the above parameters. Interestingly, retinoic acid (RA) treatment suppresses the differentiation blockade induced by high level PML-RAR alpha protein; indeed, Zn(2+)-treated MTPR9 cells incubated with RA plus D3 exhibited significant terminal monocytic maturation, comparable to that of cells treated with D3 alone or combined with RA in absence of Zn2+. Similar observations were made in NB4, a PML-RAR+ human acute leukemic line. As expected RA treatment of NB4 cells causes granulocytic differentiation. Interestingly, the cell line is only scarcely induced to mature monocytic cells by D3 or D3 plus TGF-beta 1 treatment, whereas it is effectively induced to monocytic maturation by combined treatment with D3 and RA. Accordingly, the rate of NB4 cell proliferation is only slightly affected by D3 or D3 plus TGF-beta 1 treatment, mildly inhibited by RA, and markedly decreased by D3 plus RA. These results indicate that in both U937 and NB4 cells high level PML/RAR alpha expression inhibits the monocytic terminal differentiation program triggered by D3 or D3 plus TGF-beta 1, whereas RA treatment effectively antagonizes this inhibitory PML-RAR alpha action and restores the D3 differentiative effect.

Inhibitors of poly(ADP-ribose) polymerase (PARPi) are increasingly employed as salvage therapy in epithelial ovarian cancer (EOC), but cytotoxic drug exposure along with PARP inhibition may favor development of hematological disorders. In our study, of 182 women with EOC treated with PARPi, 16 (8.7%) developed therapy-related myeloid neoplasms (t-MNs), with 12 cases of myelodysplasia and 4 of acute myeloid leukemia. All experienced persistent cytopenia after PARPi discontinuation. Seven patients had del(5q)/-5 and/or del(7q)/-7, nine had a complex karyotype and TP53 mutations, recently reported as risk factor for t-MNs in EOC post-PARPi, were found in 12 out of 13 tested patients. Four patients had a rapid and fatal outcome, one had stable disease, eleven underwent induction therapy, followed by allogeneic hematopoietic cell transplantation in seven. Three of these 11 patients experienced refractory disease, and 8 had complete remission. During a 6.8 months (range 2.3-49) median observation time, 3 out of 16 patients were alive, with one surviving patient free of both solid and hematological tumors. Ten patients died because of leukemia, two because of transplant-related events, one from heart failure. Five more patients experienced persistent cell blood count abnormalities following PARPi discontinuation, without reaching MDS diagnostic criteria. A customized Myelo-panel showed clonal hematopoiesis in all five patients. These findings confirm the actual risk of t-MNs in EOC patients after chemotherapy and prolonged PARPi therapy. The management of these patients is complex and outcomes are extremely poor. Careful diagnostic procedures are strongly recommended whenever unusual cytopenias develop in patients receiving PARPi therapy.

Aberrant activation of the Hh pathway promotes cell proliferation and multi-drug resistance (MDR) in several cancers, including Acute Myeloid Leukemia (AML). Notably, only one Hh inhibitor, glasdegib, has been approved for AML treatment, and most patients eventually relapse, highlighting the urgent need to discover new therapeutic targets. Hh signal is transduced through the membrane of the primary cilium, a structure expressed by non-proliferating mammalian cells, whose stabilization depends on the activity of HDAC6. Here we describe a positive correlation between Hh, HDAC6, and MDR genes in a cohort of adult AML patients, human leukemic cell lines, and a zebrafish model of Hh overexpression. The hyper-activation of Hh or HDAC6 in zebrafish drove the increased proliferation of hematopoietic stem and progenitor cells (HSPCs). Interestingly, this phenotype was rescued by inhibition of HDAC6 but not of Hh. Also, in human leukemic cell lines, a reduction in vitality was obtained through HDAC6, but not Hh inhibition. Our data showed the presence of a cross-talk between Hh and HDAC6 mediated by stabilization of the primary cilium, which we detect for the first time in zebrafish HSPCs. Inhibition of HDAC6 activity alone or in combination therapy with the chemotherapeutic agent cytarabine, efficiently rescued the hematopoietic phenotype. Our results open the possibility to introduce HDAC6 as therapeutic target to reduce proliferation of leukemic blasts in AML patients.

Objectives To assess efficacy of bevacizumab in combination with oral chemotherapy in patients with breast cancer with lymphangitic spread to the chest wall (LBC). To identify surrogate biomarkers of response to bevacizumab. Patients and methods We randomly assigned patients to receive bevacizumab plus either sequential or concurrent oral vinorelbine and capecitabine every 3 weeks. The primary endpoint was time to ultimate progression (TTP); the response rate and overall survival (OS) were secondary endpoints. We performed gene expression profiling on baseline tissue samples collected from triple negative LBC. We assessed circulating endothelial cells (CEC), circulating endothelial progenitors (CEP) and circulating pericyte progenitors (CPP). Results A total of 66 patients were enrolled. There was no difference in TTP (median TTP 5.3 vs. 4.8 months, p = 0.21) and in OS (median OS 15.8 vs 11.9 months; p = 0.25) when comparing concurrent vs sequential treatment, respectively. Response rate was 25% vs 28% in the concurrent vs sequential arm (p = 1.00), respectively. A set of 16 genes predictive of response to bevacizumab was identified. The counts of CEPs and viable CECs below the median value were associated with an improved overall survival: 26.6 vs 9.5 months for CEPs and 22.6 vs 11.0 months for viable CECs, respectively (p = 0.02). Conclusions Oral chemotherapy and bevacizumab (BEVIX) is an active regimen in patients with LBC. We support the importance of using LBC as a biological model for investigating angiogenesis inhibitors. CECs and CEPs biomarkers have been identified as predictive markers of outcome and warrant further investigation.