Abstract Background: Resistance to apoptosis in chronic myeloid leukemia (CML) is associated with constitutive tyrosine kinase activity of the Bcr-Abl oncoprotein. The deregulated expression of apoptosis-related genes and alteration in epigenetic machinery may also contribute to apoptosis resistance in CML. Tyrosine kinase inhibitors target the Bcr-Abl oncoprotein and are used in CML treatment. The resistance of CML patients to tyrosine kinase inhibitors has guided the search for new compounds that may induce apoptosis in Bcr-Abl+ leukemic cells and improve the disease treatment. Methods: In the present study, we investigated whether the L-amino acid oxidase isolated from Bothrops moojeni snake venom (BmooLAAO-I) (i) was cytotoxic to Bcr-Abl+ cell lines (HL-60.Bcr-Abl, K562-S, and K562-R), HL-60 (acute promyelocytic leukemia) cells, the non-tumor cell line HEK-293, and peripheral blood mononuclear cells (PBMC); and (ii) affected epigenetic mechanisms, including DNA methylation and microRNAs expression in vitro. Results: BmooLAAO-I induced ROS production, apoptosis, and differential DNA methylation pattern of regulatory apoptosis genes. The toxin upregulated expression of the pro-apoptotic genes BID and FADD and downregulated DFFA expression in leukemic cell lines, as well as increased miR-16 expression - whose major predicted target is the anti-apoptotic gene BCL2 - in Bcr-Abl+ cells. Conclusion: BmooLAAO-I exerts selective antitumor action mediated by H2O2 release and induces apoptosis, and alterations in epigenetic mechanisms. These results support future investigations on the effect of BmooLAAO-I on in vivo models to determine its potential in CML therapy.

ABSTRACT Background: Breast cancer is the neoplasm with both the highest incidence and mortality rate among women worldwide. Given the known snake venom cytotoxicity towards several tumor types, we evaluated the effects of BthTX-I from Bothrops jararacussu on MCF7, SKBR3, and MDAMB231 breast cancer cell lines. Methods: BthTX-I cytotoxicity was determined via MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide assay. Cell death was measured by a hypotonic fluorescent solution method, annexin-V-FITC/propidium iodide staining and by apoptotic/autophagic protein expression. Cancer stem cells (CSCs) were quantified by flow cytometry using anti-CD24-FITC and anti-CD44-APC antibodies and propidium iodide. Results: BthTX-I at 102 µg/mL induced cell death in all cell lines. The toxin induced apoptosis in MCF7, SKBR3, and MDAMB231 in a dose-dependent manner, as confirmed by the increasing number of hypodiploid nuclei. Expression of pro-caspase 3, pro-caspase 8 and Beclin-1 proteins were increased, while the level of the antiapoptotic protein Bcl-2 was diminished in MCF7 cells. BthTX-I changed the staining pattern of CSCs in MDAMB231 cells by increasing expression of CD24 receptors, which mediated cell death. Conclusions: BthTX-I induces apoptosis and autophagy in all breast cancer cell lines tested and also reduces CSCs subpopulation, which makes it a promising therapeutic alternative for breast cancer.

ABSTRACT Background: Cytokines are key immune mediators in physiological and disease processes, whose increased levels have been associated with the physiopathology of hematopoietic malignancies, such as myeloproliferative neoplasms. Methods: This study examined the plasma cytokine profiles of patients with essential thrombocythemia, primary myelofibrosis, polycythemia vera and of healthy subjects, and analyzed correlations with JAK2 V617F status and clinical-hematological parameters. Results: The proinflammatory cytokine levels were increased in myeloproliferative neoplasm patients, and the presence of the JAK2 V617F mutation was associated with high IP-10 levels in primary myelofibrosis patients. Conclusions: Essential thrombocythemia, primary myelofibrosis, and polycythemia vera patients exhibited different patterns of cytokine production, as revealed by cytokine network correlations. Together, these findings suggest that augmented cytokine levels are associated with the physiopathology of myeloproliferative neoplasms.

Abstract Background: Chronic myeloid leukemia (CML) is a BCR-ABL1+ myeloproliferative neoplasm marked by increased myeloproliferation and presence of leukemic cells resistant to apoptosis. The current first-line therapy for CML is administration of the tyrosine kinase inhibitors imatinib mesylate, dasatinib or nilotinib. Although effective to treat CML, some patients have become resistant to this therapy, leading to disease progression and death. Thus, the discovery of new compounds to improve CML therapy is still challenging. Here we addressed whether MjTX-I, a phospholipase A2 isolated from Bothrops moojeni snake venom, affects the viability of imatinib mesylate-resistant Bcr-Abl+ cell lines. Methods: We examined the cytotoxic and pro-apoptotic effect of MjTX-I in K562-S and K562-R Bcr-Abl+ cells and in the non-tumor HEK-293 cell line and peripheral blood mononuclear cells, using the 3-(4,5-dimethylthiazol-2-yl) −2,5-diphenyltetrazolium bromide and the hypotonic fluorescent solution methods, associated with detection of caspases 3, 8, and 9 activation and poly (ADP-ribose) polymerase (PARP) cleavage. We also analyzed the MjTX-I potential to modulate the expression of apoptosis-related genes in K562-S and K562-R cells. Results: MjTX-I decreased the viability of K562-S and K562-R cells by 60 to 65%, without affecting the viability of the non-tumor cells, i.e. it exerted selective cytotoxicity towards Bcr-Abl+ cell lines. In leukemic cell lines, the toxin induced apoptosis, activated caspases 3, 8, and 9, cleaved PARP, downregulated expression of the anti-apoptotic gene BCL-2, and upregulated expression of the pro-apoptotic gene BAD. Conclusion: The antitumor effect of MjTX-I is associated with its potential to induce apoptosis and cytotoxicity in Bcr-Abl positive cell lines sensitive and resistant to imatinib mesylate, indicating that MjTX-I is a promising candidate drug to upgrade the CML therapy.

Background Activation of the complement system plays an important role in the regulation of immune and inflammatory reactions, and contributes to inflammatory responses triggered by envenomation provoked byBothrops snakes. The present study aimed to assess whether Bothrops jararacussuand Bothrops pirajai crude venoms and their isolated toxins, namely serine protease (BjussuSP-I) and L-amino acid oxidase (BpirLAAO-I), modulate human complement system pathways.Methods Lyophilized venom and toxin samples solubilized in phosphate buffered saline were diluted in appropriate buffers to evaluate their hemolytic activity on the alternative and classical pathways of the complement system. Venom- and toxin-treated normal human serum was added to the erythrocyte suspension, and the kinetic of hemolysis was measured spectrophotometrically at 700 nm. The kinetic 96-well microassay format was used for this purpose. We determined the t ½values (time required to lyse 50 % of target erythrocytes), which were employed to calculate the percentage of inhibition of the hemolytic activity promoted by each sample concentration. To confirm complement system activation, complement-dependent human neutrophil migration was examined using the Boyden chamber model.Results At the highest concentration tested (120 μg/mL), B. jararacussu and B. pirajai crude venoms inhibited the hemolytic activity of the classical pathway (65.3 % and 72.4 %, respectively) more strongly than they suppressed the hemolytic activity of the alternative pathway (14.2 and 13.6 %, respectively). BjussuSP-I (20 μg/mL) did not affect the hemolytic activity of the classical pathway, but slightly decreased the hemolytic activity of the alternative pathway (13.4 %). BpirLAAO-I (50 μg/mL) inhibited 24.3 and 12.4 % of the hemolytic activity of the classical and alternative pathways, respectively. Normal human serum treated with B. jararacussu and B. pirajai crude venoms induced human neutrophil migration at a level similar to that induced by zymosan-activated normal human serum.Conclusion Together, the results of the kinetics of hemolysis and the neutrophil chemotaxis assay suggest that pre-activation of the complement system byB. jararacussu and B. pirajai crude venoms consumes complement components and generates the chemotactic factors C3a and C5a. The kinetic microassay described herein is useful to assess the effect of venoms and toxins on the hemolytic activity of the complement system.

As neoplasias mieloproliferativas crônicas cromossomo Filadélfia negativas são doenças hematológicas clonais que se caracterizam pela independência ou pela hipersensibilidade dos progenitores hematopoiéticos às citocinas. Os mecanismos celulares e moleculares envolvidos na fisiopatologia das neoplasias mieloproliferativas crônicas ainda não estão totalmente esclarecidos. Achados fisiopatológicos relevantes para as neoplasias mieloproliferativas crônicas estão associados às alterações genéticas como, por exemplo, a mutação somática no gene que codifica o JAK2 (JAK2V617F). A desregulação do processo de morte celular programada, denominada apoptose, parece participar da patogênese dessas desordens. Sabe-se que a desregulação da expressão dos genes pró- e antiapoptóticos promove a resistência das células à apoptose, culminando com o acúmulo das células mieloides e estabelecendo a neoplasia. Esta revisão enfocou as alterações na regulação da apoptose em neoplasias mieloproliferativas crônicas e a importância da melhor compreensão desse mecanismo para o desenvolvimento de novas terapias para essas doenças.

Philadelphia-chromosome negative chronic myeloproliferative neoplasms are clonal hematologic diseases characterized by hematopoietic progenitor independence from or hypersensitivity to cytokines. The cellular and molecular mechanisms involved in the pathophysiology of myeloproliferative neoplasms have not yet been fully clarified. Pathophysiologic findings relevant for myeloproliferative neoplasms are associated with genetic alterations, such as, somatic mutation in the gene that codifies JAK-2 (JAK V617F). Deregulation of the process of programmed cellular death, called apoptosis, seems to participate in the pathogenesis of these disorders. It is known that expression deregulation of pro- and anti-apoptotic genes promotes cell resistance to apoptosis, culminating with the accumulation of myeloid cells and establishing neoplasms. This review will focus on the alterations in apoptosis regulation in myeloproliferative neoplasms, and the importance of a better understanding of this mechanism for the development of new therapies for these diseases.

The retrovirus human T lymphotropic virus type 1 (HTLV-1) promotes spastic paraparesis, adult T cell leukaemia and other diseases. Recently, some human microRNAs (miRNAs) have been described as important factors in host-virus interactions. This study compared miRNA expression in control individuals, asymptomatic HTLV-1 carriers and HTLV-1 associated myelopathy (HAM)/tropical spastic paraparesis patients. The proviral load and Tax protein expression were measured in order to characterize the patients. hsa-miR-125b expression was significantly higher in patients than in controls (p = 0.0285) or in the HAM group (p = 0.0312). Therefore, our findings suggest that miR-125b expression can be used to elucidate the mechanisms of viral replication and pathogenic processes.

INTRODUÇÃO: Na identificação de cepas de Salmonella, os métodos de sorotipagem e ribotipagem na detecção de marcadores epidemiológicos são os mais utilizados nos laboratórios de referência mundiais. Esses métodos moleculares são imprescindíveis na vigilância epidemiológica e permitem a detecção da fonte da infecção. OBJETIVOS: O presente trabalho objetivou caracterizar as cepas de Salmonella Enteritidis pela ribotipagem. MATERIAL E MÉTODOS: Trinta e oito cepas de S. Enteritidis foram isoladas de pacientes atendidos no Hospital das Clínicas da Universidade de São Paulo, Ribeirão Preto, SP, entre os anos de 1996 e 1998. As cepas foram isoladas de fezes (31 amostras), sangue (quatro amostras) e outros fluidos (três amostras). As cepas de Salmonella foram isoladas utilizando-se métodos bacteriológicos de rotina, sorotipadas e ribotipadas. RESULTADOS: As 38 cepas de S. Enteritidis apresentaram na ribotipagem a separação das cepas em dois ribotipos: A (94,7% das amostras) e B (5,3% das amostras). DISCUSSÃO E CONCLUSÃO: Esses dados sugerem que grande parte dos pacientes (94,7%) foi infectada pela mesma cepa. Essa cepa pode ser endêmica na comunidade de Ribeirão Preto ou os pacientes foram expostos a uma fonte comum de infecção.

BACKGROUND: The approach generally employed in leading laboratories worldwide to identify strains of Salmonella is to detect epidemiological markers by serotyping and molecular techniques. These molecular methods are important in sanitary surveillance and lead to the source of infection. OBJECTIVES: The aim of the present study is to characterize Salmonella Enteritidis strains by ribotyping. MATERIAL AND METHODS: Thirty-eight strains of S. Enteritidis were isolated from in patients at the university hospital of Universidade de São Paulo, Ribeirão Preto, SP, Brazil, between 1996 and 1998. These strains were isolated from stools (31 samples), blood (4 samples) and other body fluids (3 samples), using routine bacteriological methods, and were serotyped and ribotyped. RESULTS: The 38 strains of serotype S. Enteritidis were shown by the ribotyping to belong to two ribotypes: A (94.7% of the samples) and B (5.3%). DISCUSSION AND CONCLUSION: These results suggest that the majority of patients (94.7%) were infected by the same strain. This strain could be endemic in the Ribeirão Preto community, or these patients may have been exposed to a common source of infection.

INTRODUÇÃO: Na literatura, numerosas publicações relatam a determinação do estado férrico em crianças, adolescentes e mulheres em fase reprodutiva, no entanto são raras as pesquisas quanto às alterações do ferro em estoque e eritrograma pós-terapia de reposição hormonal (TRH) em pré-menopausadas e menopausadas. O aumento dos estoques de ferro em mulheres pré-menopausadas e menopausadas pode conduzir à elevação do estresse oxidativo e, conseqüentemente, ao risco de desenvolvimento de câncer e doenças cardiovasculares. OBJETIVO: Avaliar o efeito da TRH sobre o eritrograma e o estado férrico em mulheres na pré-menopausa e na menopausa. MÉTODOS: Foram determinados os eritrogramas e as dosagens de ferro, capacidade total de ligação do ferro a transferrina (CTLF) e ferritina séricas em 30 mulheres no climatério antes e após seis meses de TRH com medroxiprogesterona e estradiol. Os eritrogramas, as dosagens de ferro e CTLF foram determinados por meio da utilização de métodos clássicos, e a ferritina, por quimiluminescência. RESULTADOS: Após o uso da TRH, constataram-se significante redução do número de eritrócitos, elevação dos índices hematimétricos e tendência à diminuição nos níveis de ferro sérico e CTLF. Nenhuma alteração significante nos níveis de ferritina e no índice de saturação de transferrina foi detectada após a TRH. DISCUSSÃO E CONCLUSÃO: No presente estudo não foram encontradas alterações nos parâmetros hematimétricos e no estado férrico que impeçam a utilização da TRH no climatério e na menopausa. Os resultados sugerem que a TRH exerceu efeito benéfico sobre o estado férrico nas mulheres no climatério deste estudo, mantendo os estoques de ferro normais e promovendo a elevação dos índices hematimétricos.

BACKGROUND: In literature there are many studies about iron status in children, adolescents and fertile women, but investigations of iron stores and erythrocyte parameters variation after hormone replacement therapy (HRT) are rare. Elevated iron stores, oxidative stress, and estrogen deficiency may place premenopausal and menopausal women in a risk of developing heart disease and cancer. OBJECTIVE: To evaluate the effect of HRT in erythrogram and iron status in premenopausal and menopausal women. METHODS: Hematological indices and iron status were assessed by erythrogram, serum ferritin, iron and transferrin iron-binding capacity (TIBC) in 30 pre- and menopausal women before and after HRT with medroxiprogesterone and estradiol. The blood exam, serum iron and iron-binding capacity were determined by laboratory classic methods, while ferritin was measured by quimiluminescent assay. RESULTS: HRT use was followed by a significant reduction in the absolute number of erythrocyte, an increase of hematimetric indexes and a trend towards a reduction of serum iron levels and TIBC. No alterations on serum ferritin and transferrin saturation index were detected after HRT. DISCUSSION AND CONCLUSION: In the present study, alterations in red cell and iron parameters, which could impair the use of HRT in premenopausal and menopausal women, were not observed. Our results suggest that HRT in premenopausal women are beneficial to iron status, maintaining normal iron stores and promoting elevation of red cells indexes.

Salmonella strains isolated from 1,138 samples representing 28,199 biological materials (stool, urine, blood and other fluids), collected between January 1985 and January 1999 at a reference University Hospital in Ribeirão Preto, São Paulo, Brazil, were studied. The most frequently detected serotypes were Salmonella enterica subspecies enterica serotype4,5,12:i:- (S. I 4,5,12:i:) (21.2%), S. agona (15.8%) and S. enteritidis (11.3%). A changing pattern of Salmonella serotypes was observed between 1985-1999. S. agona, which represented 27% of Salmonella serotypes isolated from 1985-1989, declined to 4% during the period from 1995 to 1999. S. enteritidis isolation remained below 1% until 1989; rose to 5.9% between 1990 and 1994, and increased to 32.3% between 1995-1999. S. I 4,5,12:i:-; S. Enteritidis; S. Typhimurium; S. dublin and S. infantis, showed low to moderate resistance profiles to most antimicrobial drugs. Nalidixic acid and tetracycline were the most and the least effective drugs, respectively, in the disk diffusion tests. We encountered changes in salmonellosis epidemiology in this geographical region.