[Show abstract][Hide abstract] ABSTRACT: Rosai-Dorfman disease (RDD) is a nonmalignant histiocytic disorder of unknown origin that is extremely rare. By immunohistochemistry, the RDD cells are characteristically S-100 positive and CD1a negative. Emperipolesis is a common histopathological finding, although not specific for RDD. Lymph node and cutaneous manifestations are most frequent, but diverse organs can be affected. The clinical course is unpredictable regardless of treatment. Here, we present a series of 8 cases presenting lymph node and/or cutaneous lesions. Lymph node involvement was seen in diverse regions, including mediastinal and retroperitoneal. The treatment response to steroids was diversified, and the chemotherapy response was disappointing. Associated autoimmune diseases (Sjögren syndrome and antiphospholipid syndrome) were observed in 2 patients. Regardless of therapy modality, these patients exhibited a favorable prognosis in a follow-up duration that ranged from 15 to 80 months.
Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas / Sociedade Brasileira de Biofisica ... [et al.] 10/2014; · 1.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Acute myeloid leukemia (AML) patients' outcome is usually poor, mainly because of drug resistance phenotype. The identification of new drugs able to overcome mechanisms of chemoresistance is essential. The pterocarpanquinone LQB-118 compound has been shown to have a potent cytotoxic activity in myeloid leukemia cell lines and patient cells. Our aim was to investigate if LQB-118 is able to target FoxO3a and FoxM1 signaling pathways while sensitizing AML cell lines. LQB-118 induced apoptosis in both AML cell lines HL60 (M3 FAB subtype) and U937 (M4/M5 FAB subtype). Cell death occurred independently of alterations in cell cycle distribution. In vivo administration revealed that LQB-118 was not cytotoxic to normal bone marrow-derived cells isolated from mice. LQB-118 induced FoxO3a nuclear translocation and upregulation of its direct transcriptional target Bim, in HL60 cells. However, LQB-118 induced FoxO3a nuclear exclusion, followed by Bim downregulation, in U937 cells. Concomitantly, LQB-118 exposure reduced FoxM1 and Survivin expression in U937 cells, but this effect was more subtle in HL60 cells. Taken together, our data suggest that LQB-118 has a selective and potent antitumor activity against AML cells with distinct molecular subtypes, and it involves differential modulation of the signaling pathways associated with FoxO3a and FoxM1 transcription factors.
International Journal of Oncology 08/2014; · 2.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose This study determined the frequency of clinical features, reactivations, sequelae, mortality, and overall survival (OS) and compared paediatric with adult Langerhans cell histiocytosis (LCH) patients. Materials and methods Ninety patients (60 paediatric and 30 adults) with LCH treated during 28 years were analysed retrospectively. Results Craniofacial lesion was the most frequent lesion at LCH presentation in children and adults. However, some differences were found. Orbital lesions were more frequent in paediatric than adult patients (P = 0.001). There was a tendency for mandible lesions to be more common in adults than the paediatric group (P = 0.0710). Mucocutaneous lesions were observed in a higher proportion in adults compared to paediatric patients (P = 0.0395). Reactivation episodes (36.8 versus 62.5%) and deaths (10.7 versus 24.0%) occurred in lower proportions in paediatric than adult patients, respectively. The probability of OS in 10 years for both groups was similar (P = 0.137). Conclusion The OS was similar in both groups despite clinical differences between paediatric and adult patients, and higher reactivation and death rates in adults.
[Show abstract][Hide abstract] ABSTRACT: ABCB1/P-glycoprotein (Pgp) and ABCG2/BCRP overexpression have been described as related to imatinib resistance in chronic myeloid leukemia (CML). We showed in CML cells from 55 patients that Pgp activity was more frequently detected than BCRP activity (p=0.0074). Imatinib-induced Crkl phosphorylated protein (pCrkl) reduction was more pronounced in K562 (Pgp-negative) than in K562-Lucena (Pgp-positive) CML cell line. Expressive pCrkl reduction levels after in vitro imatinib treatment was observed in samples from patients exhibiting lower Pgp activity levels compared with patients exhibiting higher Pgp activity levels (p=0.0045). Pgp activity in association with pCrkl reduction levels might help to distinguish between imatinib-resistant and imatinib-sensitive CML cells.
[Show abstract][Hide abstract] ABSTRACT: The hallmark of chronic myeloid leukemia (CML) is the BCR-ABL fusion gene. CML evolves through three phases, based on both clinical and pathological features: a chronic phase, an accelerated phase and blast crisis. Tyrosine kinase inhibitors are the treatment modality for patients with chronic phase CML. The therapeutic potential of imatinib is affected by BCR-ABL dependent an independent mechanisms. Development of multidrug resistance (MDR) contributes to the overall clinical resistance. MDR involves overexpression of ABC-transporters among other features. MDR studies include the analysis of cancer cell lines selected for resistance. CML blast crisis is accompanied by increased resistance to apoptosis. This work reviews the role played by the influx transporter OCT1, by efflux ABC transporters, molecules involved in the modulation of apoptosis (p53, Bcl-2 family, CD95, IAPs), Hh and Wnt/β-catenin pathways, cytoskeleton abnormalities and other features described in leukemic cells of clinical samples and CML cell lines. A MDR cell line, Lucena-1, generated from K562 by stepwise exposure to vincristine, was used as our model and some potential anticancer drugs effective against the MDR cell line and patients' samples are presented.
[Show abstract][Hide abstract] ABSTRACT: P-glycoprotein (Pgp) and XIAP co-expression has been discussed in the process of the acquisition of multidrug resistance (MDR) in cancer. Here, we evaluated XIAP and Pgp expression in chronic myeloid leukemia (CML) samples, showing a positive correlation between them. Furthermore, we evaluated the effects of imatinib in XIAP and Pgp expression using CML cell lines K562 (Pgp(-)) and K562-Lucena (Pgp(+)). Imatinib increased XIAP and Pgp expression in K562-Lucena cells, while in K562 cells a downregulation of these proteins was observed, suggesting that imatinib induces an increment of MDR phenotype of CML cells that previously exhibit high levels of Pgp/XIAP co-expression.
[Show abstract][Hide abstract] ABSTRACT: Using MTT, Annexin V/flow cytometry, immunocytochemistry, subcellular fractionation, and Western blotting assays we analyzed the effect of imatinib in two blast phase of chronic myeloid leukemia (CML) cell lines: K562 P-glycoprotein (Pgp)-negative, and Lucena, Pgp-positive. In K562 cell line, the high apoptosis index induced by imatinib was associated with the survivin predominantly in the nucleus. In the Lucena cell line, the low apoptosis index induced by imatinib was associated with a cytoplasmatic survivin localization. Pgp and survivin might be subject to the same molecular regulation, and therefore represent a therapeutic target in the blast phase of CML.
[Show abstract][Hide abstract] ABSTRACT: Acute myeloid leukemia (AML) is a challenging neoplasm that despite therapeutic advances requires efforts to overcome the multidrug resistance (MDR) phenotype, the major cause of relapse. The pterocarpanquinone LQB-118 is a new compound that induces apoptosis in leukemia cells. The objective of this work was to analyze the role of LQB-118 in inhibiting the inhibitor of apoptosis proteins (IAPs), XIAP and survivin, as well as in modulating the subcellular localization of NFκB, in comparison with idarubicin. LQB-118 was more effective in inducing apoptosis than idarubicin in both AML Kasumi-1 cell line and cells from patients despite their MDR phenotype. LQB-118-induced apoptosis was accompanied by a marked inhibition of IAPs, and cytoplasmatic NFκB subcellular localization. On the other hand, idarubicin increased the IAPs expression and translocated NFκB to the nucleus. The inhibition profile of survivin induced by LQB-118 was comparable to the survivin inhibition profile when we investigated the efficiency of survivin-small interfering RNA (siRNA) treatment. LQB-118 as well as survivin-siRNA contributed similarly to the increase in apoptosis rate of Kasumi-1 cells. The data indicated that there is a functional interaction between the survivin, XIAP and NFκB, which appears to be involved in idarubicin resistance of Kasumi-1 cells. The efficacy of LQB-118 to induce cell death though inhibiting survivin suggests that this IAP may be involved in the chemoresistance phenotype in AML cells. Our findings suggest that LQB-118 might be a promising therapeutic approach for AML patients through survivin downregulation.
Anti-cancer agents in medicinal chemistry 06/2012;
[Show abstract][Hide abstract] ABSTRACT: Centroblastic diffuse large B cell lymphoma (DLBCL) samples were analyzed by immunohistochemistry to evaluate the expression of p53, Bcl-2, Survivin, XIAP, and Ki-67. Survivin was the only protein which expression exhibited a trend for impact in progression-free (p = .077) and overall survival (p = .054). In the Mann-Whitney test, Survivin expression correlated with a negative overall survival (p = .045). These results appeared to be intimately related to Survivin cytoplasmic localization. Moreover, the anti-apoptotic proteins Bcl-2 and Survivin were less frequent in centroblastic DLBCL. Our results indicate that centroblastic DLBCL may be a disease with characteristic biology and clinical course and, therefore, specific prognostic factors.
Cancer Investigation 06/2012; 30(5):404-14. · 2.24 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Polymorphisms in the ABCB1 gene may influence P-glycoprotein (Pgp) expression and/or activity. Because the population in Brazil is markedly heterogeneous, we analyzed the relationship between ABCB1 polymorphisms and Pgp expression/activity in Brazilian acute myeloid leukemia (AML) patients.
Acute myeloid leukemia samples from 109 patients were studied. ABCB1 gene variants rs1128503 (C1236T) and rs1045643 (C3435T) were analyzed by PCR-RFLP assay. Pgp expression and Pgp activity were analyzed by flow cytometry.
There was a similar distribution of Pgp expression and activity on polymorphisms C1236T, C1236C, and T1236T for exon 12, and C3435T, C3435C, and T3435T for exon 26. An exception was observed in the lowest ratio of mean fluorescence intensity (MFI) median for Pgp expression in the TT genotype for both studied exons, and its correspondence to a low MFI median for Pgp activity. Pgp expression did not show impact on the response to remission induction therapy, but the MFI median of Pgp expression in the remission failure group was higher than that of the complete remission (CR) group of patients (p = 0.04). Overall survival (OS) was significantly influenced by CR (p = 0.0001). Better 5-year OS and 5-year event-free survival rates (p = 0.04 and p = 0.007, respectively) were achieved in patients presenting the genetic variant CC in exon 12 followed by those presenting the variant CT in exon 26 (p = 0.001).
Polymorphisms in the ABCB1 gene and the levels of Pgp expression could be useful to identify prognostic in AML patients.
Journal of Cancer Research and Clinical Oncology 02/2012; 138(6):959-69. · 2.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Multidrug resistance (MDR) is considered a multifactorial phenotype which prevents a successful clinical cancer treatment. This phenomenon is mainly associated with mechanisms that include drug extrusion by P-glycoprotein (Pgp) overexpression and resistance to apoptosis derived by members of the inhibitor of apoptosis proteins (IAPs), such as XIAP. Studies have proposed the use of compounds that are able to inhibit or modulate Pgp function, with no changes in the physiological expression of this protein. Based on that, the present study aimed to evaluate the reversal of MDR phenotype through modulation of Pgp efflux pump activity in leukemia multidrug-resistant cells, using a low dose of cyclosporine A (CsA). We showed that modulation of Pgp activity by using CsA did not induce cytotoxic effects in leukemia cells, independently of Pgp expression. However, during the modulation condition, we could observe that vincristine-induced apoptosis was significant in resistant cells, which was also coupled with decreasing expression of the inhibitor of apoptosis protein XIAP. In summary, our data suggest that CsA is able to reversing MDR phenotype in vitro, inducing sensibility in multidrug-resistant cells with no alterations in Pgp expression. These findings contribute to our knowledge for the circumvention of MDR in cancer cells and could be helpful for new treatment approaches.
[Show abstract][Hide abstract] ABSTRACT: Chronic myeloid leukemia (CML) is a clonal hematopoietic disorder characterized by the presence of the Philadelphia chromosome which resulted from the reciprocal translocation between chromosomes 9 and 22. The pathogenesis of CML involves the constitutive activation of the BCR-ABL tyrosine kinase, which governs malignant disease by activating multiple signal transduction pathways. The BCR-ABL kinase inhibitor, imatinib, is the front-line treatment for CML, but the emergence of imatinib resistance and other tyrosine kinase inhibitors (TKIs) has called attention for additional resistance mechanisms and has led to the search for alternative drug treatments. In this paper, we discuss our current understanding of mechanisms, related or unrelated to BCR-ABL, which have been shown to account for chemoresistance and treatment failure. We focus on the potential role of the influx and efflux transporters, the inhibitor of apoptosis proteins, and transcription factor-mediated signals as feasible molecular targets to overcome the development of TKIs resistance in CML.
Leukemia research and treatment. 01/2012; 2012:671702.
[Show abstract][Hide abstract] ABSTRACT: Overexpression of P-glycoprotein (Pgp/ABCB1) in tumor cells is associated with a classic phenotype of multidrug resistance (MDR). Moreover, some members of the inhibitor of apoptosis protein (IAP) family, such as survivin, contribute to an apoptosis-resistant phenotype, by inhibiting chemotherapy-induced cell death and promoting MDR. By using Western blotting, qRT-PCR, Annexin V and immunofluorescence assays we have demonstrated a relationship between Pgp and survivin in a prior sensitive chronic myeloid leukemia (CML) cell line (K562). A high dose of vincristine induced a concomitant overexpression of Pgp and survivin, which was associated with a low apoptotic index in the K562 cell line. In addition, we observed a cytoplasmic co-localization of Pgp and survivin, suggesting a functional association between these two proteins in apoptosis control by a common mechanism. In summary, our data suggest that Pgp and survivin should be analyzed in aggregate because they may have significant impact on drug resistance in CML cells.
International Journal of Oncology 06/2011; 39(4):925-33. · 2.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Medulloblastoma (MDB) is the most common malignant cerebellar tumor in children. Because of the significant rate of mortality and treatment-related morbidity, the identification of prognostic factors could lead to a more accurate selection of patients who can benefit from a less aggressive therapy and improve risk stratification. Survivin is an inhibitor of apoptosis protein (IAP), the expression of which has been associated with worse prognosis in MDB. However, both of its subcellular localizations may contribute to tumor progression, and ultimately, survivin subcellular localization prognostic value depends on tumor type biological features. The goal of this study was to analyze these survivin features in the pediatric MDB tumor samples and its impact on clinical outcome. Survivin expression and subcellular localization were accessed by immunohistochemistry in a series of 41 tumor samples. Kaplan-Meier survival curves were compared using the log-rank test. Survivin expression ranged from completely absent to fully present in a notably higher pattern of nuclear localization than cytoplasmic (19 of 41 versus 4 of 41, respectively). However, survivin expression and subcellular localization were not associated with five-year overall survival or metastasis status at diagnosis, which was the only statistically significant prognostic factor in our series (p = 0.008). Taken together, our results suggest that survivin expression should be further studied in large, multicenter series to determine its accurate impact on prognosis and pathobiology of pediatric MDB.
Pathology & Oncology Research 06/2011; 17(4):899-908. · 1.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The involvement of the multidrug resistance (MDR) mediated by ABC transporter proteins P-glycoprotein (Pgp) and multidrug resistance-associated protein-1 (MRP1) overexpressions in patients with chronic myeloid leukemia (CML) are not completely understood. Pgp and MRP1 expressions and activity were analyzed in samples from 158 patients with chronic myeloid leukemia (CML). Using flow cytometry, Pgp expression was more frequently observed in early chronic (P = 0.00) and in advanced (P = 0.02) CML phases when it was compared to MRP1 expression. Variation of MDR expression and activity were observed during the CML evolution in patients previously treated with interferon and imatinib. In the K562-Lucena cell line, Pgp positive, imatinib caused an enhancing in Pgp expression at protein and mRNA levels, whereas in the Pgp negative cell line, this drug was capable of decreasing MDR1/Pgp mRNA levels. Our result emphasizes the importance of understanding the different aspects of MDR status in patients with CML when they are under investigation in determining imatinib resistance.
Cytometry Part B Clinical Cytometry 05/2011; 80(3):158-66. · 2.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Survivin is a member of the inhibitor of apoptosis protein family (IAP) that acts in both inhibition of apoptosis and regulation of the cell cycle. Despite the fact that survivin is overexpressed in almost all human malignancies, its expression is undetectable in most normal adult tissues, which is what makes it a potential target for anticancer interventions. The aim of this work was to investigate whether survivin is involved in resistance to idarubicin (ida), a drug commonly used in leukemia treatment. Cytotoxic assays using MTT showed that 1 µM of ida could inhibit 50% of cell viability in K562, a chronic myeloid leukemia cell line. Western blotting analysis revealed that survivin expression was increased in the cell line after treatment with ida 0.5 and 1 µM concentrations, protecting cells from ida-induced apoptosis. However, the highest ida concentrations tested were able to inhibit survivin levels and induce apoptosis in K562 cells, as evaluated by morphology and caspase-3 and -9 activation. These results indicate that survivin expression is involved in ida resistance in K562 leukemic cells. Flow cytometry analysis of the cell cycle showed that ida induced G2/M arrest in these cells and there was a statistically significant positive correlation between survivin expression and the percentage of cells in G2/M phase. This work supports the idea that survivin may contribute to an apoptosis-resistant phenotype by inhibiting ida-induced apoptosis and preventing cells from progressing in the cell cycle.
[Show abstract][Hide abstract] ABSTRACT: p53 is a cell cycle checkpoint control protein that assesses DNA damage and acts as a transcription factor regulating genes, which control cell growth, DNA repair, and apoptosis. p53 mutations have been found in a wide variety of different cancers including flow cytometric assessment of p53 protein expression using anti-p53 monoclonal antibodies. We studied p53 protein expression by flow cytometry (FC) assay in 223 blood and/or bone marrow samples from 72 patients with chronic myeloid leukemia (CML): 54 in chronic phase (CML-CP), 7 in accelerated phase (CML-AP), and 11 in blastic phase (CML-BP); 64 patients with chronic lymphoid leukemia (CLL): (34 at diagnosis, 21 in previously treated, and 9 with Richter's syndrome); 44 patients with acute lymphoid leukemia (ALL): 36 at diagnosis and 8 in relapse; and 43 acute myeloid leukemia (AML): 27 de novo, 7 in relapse, and 9 secondary. p53 protein expression was observed in 64 of 223 patient's samples: 14/64 (21.9%) CLL, 13/44 (29.5%) ALL, 19/43 (44.2%) AML, and 17/72 (23.6%) CML. Highest levels were detected in the advanced phases of CLL, ALL, and CML. In addition, in patients with AML, high levels of p53 expression were detected in secondary and relapse disease and also in de novo AML cases. Our results demonstrated that p53 expression levels are strongly associated with advanced disease. On the basis of these results, we concluded that FC can be a reliable approach to study p53 protein expression in leukemic patients.
Cytometry Part B Clinical Cytometry 03/2010; 78(4):253-9. · 2.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The ABCB1/MDR-1 gene, which encodes P-glycoprotein, is highly polymorphic. We analyzed 278 healthy Brazilian individuals through PCR–RFLP
to identify ABCB1 variants and determine the genotypic and allelic frequencies. Genotypic frequencies for C1236T (rs1128503) were 0.31 for
CC, 0.60 for CT and 0.09 for TT and allelic frequencies were 0.61 and 0.39 for C and T, respectively. Genotypic frequencies
for C3435T (rs1045642) were 0.24 for CC, 0.61 for CT and 0.15 for TT, and allelic frequencies were 0.55 and 0.45 for C and
T, respectively. Both variants showed significant differences in genotypic frequencies for both studied regions. Gender comparisons
did not show significant differences between genotypes at both sites. Significant differences were observed between C1236C
and C3435T and also C1236C and C3435C. Comparisons between ABCB1 polymorphisms in Brazilians and other populations show significant differences. The understanding of the effects of several
drugs associated to these variants may help an individualized treatment in clinical practice.
[Show abstract][Hide abstract] ABSTRACT: p53 protein induces cell cycle arrest, DNA repair, or apoptosis of damaged cells. Loss of wild-type p53 (wt-p53) function was shown to be associated with upregulation of survivin and resistance to therapy. Here we investigated the effects of DNA-damage agents in inducing apoptosis and cell cycle arrest, and modulation of survivin levels in two Burkitt's lymphoma (BL) cell lines with different p53 mutations. Our results showed that BL cell lines have variable response to DNA-damaging agents that cannot be correlated exclusively with p53 mutation or survivin expression suggesting that p53-independent transactivation may play a role in apoptosis induced by DNA-damaging agents.
Cancer Investigation 07/2009; 27(8):830-5. · 2.24 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Survivin, a member of the inhibitor of apoptosis protein family and a target for new drugs, is modulated by reactive oxygen species in several types of neoplasms including leukemias. The aim of this study is to find mechanisms to enhance sensitivity to imatinib in imatinib-responsive cells. In this study, we demonstrated through fluorescein isothiocyanate-labeled annexin V for apoptotic cells detection and western blotting that by inhibiting catalase activity, imatinib apoptosis induction was significantly enhanced (P<0.05) through diminishing survivin expression in K562 cells. These findings might be of clinical relevance and might help improve the chemotherapeutic use of imatinib mesylate.