Effect of Cyr61 on Imatinib Resistance in Chronic Myeloid Leukemia and Its Mechanism / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of Cyr61 on imatinib (IM) resistance in chronic myeloid leukemia (CML) and its mechanism.@*METHODS@#Cyr61 level in cell culture supernatant was determined by enzyme-linked immunosorbent assay. The expression of Cyr61 and Bcl-xL were measured by real-time PCR and Western blot. Cell apoptosis was analyzed using an Annexin V-APC Kit. Expression of signal pathways related proteins was determined by Western blot.@*RESULTS@#The level of Cyr61 obviously increased in K562G cells (IM resistance to CML cell line K562). Down-regulating the expression of Cyr61 decreased the resistance of K562G cells to IM and promoted IM induced apoptosis. In CML mouse model, down-regulating the expression of Cyr61 could increase the sensitivity of K562G cells to IM. The mechanism studies showed that Cyr61 mediated IM resistance in CML cells was related to the regulation of ERK1/2 pathways and apoptosis related molecule Bcl-xL by Cyr61.@*CONCLUSION@#Cyr61 plays an important role in promoting IM resistance of CML cells. Targeting Cyr61 or its related effectors pathways may be one of the ways to overcome IM resistance of CML cells.

Effects of Dasatinib on the Maturation of Monocyte-Derived Dendritic Cells Derived from Healthy Donors and Chronic Myelogenous Leukemia Patients / 中国实验血液学杂志

OBJECTIVE@#To investigate the effects of dasatinib on the maturation of monocyte-derived dendritic cells (moDCs) derived from healthy donors (HDs) and chronic myelogenous leukemia (CML) patients.@*METHODS@#Peripheral blood mononuclear cells (PBMCs) were isolated from HDs (n=10) and CML patients (n=10) who had got the remission of MR4.5 with imatinib treatment. The generation of moDCs from PBMCs was completed after 7 days of incubation in DC I culture medium, and another 3 days of incubation in DC II culture medium with or without 25 nmol/L dasatinib. On the 10th day, cells were harvested and expression of molecules of maturation related marker were assessed by flow cytometry. The CD80+CD86+ cell population in total cells was gated as DCs in the fluorescence-activated cell storting (FACS) analyzing system, then the expression of CD83, CD40 or HLA-DR in this population was analyzed respectively.@*RESULTS@#The proportion of CD80+CD86+ cells in total cells didn't show a statistical difference between HD group and patient group (89.46%±9.70% vs 87.39%±9.34%, P=0.690). Dasatinib significantly enhanced the expression of the surface marker CD40 (P=0.008) and HLA-DR (P=0.028) on moDCs derived from HDs compared with the control group, while the expression of CD83 on moDCs didn't show a significant difference between dasatinib group and the control group (P=0.428). Meanwhile, dasatinib significantly enhanced the expression of the surface marker CD40 (P=0.023), CD83 (P=0.038) and HLA-DR (P=0.001) on moDCs derived from patients compared with the control group.@*CONCLUSION@#For CML patients, the same high proportion of moDCs as HDs can be induced in vitro, which provides a basis for the application of DC-based immunotherapy strategy. Dasatinib at the concentration of 25 nmol/L can efficiently promote the maturation of moDCs derived from HDs and CML patients in vitro. Dasatinib shows potential as a DC adjuvant to be applied in DC-based immunotherapy strategies, such as DC vaccine and DC cell-therapy.

A combination of STI571 and BCR-ABL1 siRNA with overexpressed p15INK4B induced enhanced proliferation inhibition and apoptosis in chronic myeloid leukemia

p15INK4B, a cyclin-dependent kinase inhibitor, has been recognized as a tumor suppressor. Loss of or methylation of the p15INK4B gene in chronic myeloid leukemia (CML) cells enhances myeloid progenitor formation from common myeloid progenitors. Therefore, we examined the effects of overexpressed p15INK4B on proliferation and apoptosis of CML cells. Overexpression of p15INK4B inhibited the growth of K562 cells by downregulation of cyclin-dependent kinase 4 (CDK4) and cyclin D1 expression. Overexpression of p15INK4B also induced apoptosis of K562 cells by upregulating Bax expression and downregulating Bcl-2 expression. Overexpression of p15INK4B together with STI571 (imatinib) or BCR-ABL1 small interfering RNA (siRNA) also enhanced growth inhibition and apoptosis induction of K562 cells. The enhanced effect was also mediated by reduction of cyclin D1 and CDK4 and regulation of Bax and Bcl-2. In conclusion, our study may provide new insights into the role of p15INK4B in CML and a potential therapeutic target for overcoming tyrosine kinase inhibitor resistance in CML.

Transcripto BCR-ABL atípico en un paciente con leucemia mieloide crónica / Atypical BCR-ABL transcript in a patient with chronic myeloid leukemia

Se presenta un paciente con leucemia mieloide crónica (LMC) y un transcripto BCR-ABL atípico. Mediante el análisis cualitativo de los productos de la reacción en cadena de la polimerasa, y por comparación con los pesos moleculares del producto de amplificación de muestras de pacientes positivos a los puntos de ruptura más frecuentes e13a2 (b2a2) y e14a2 (b3a2), se determinó que el gen quimérico BCR-ABL de este paciente debe corresponder al transcripto e13a3 (b2a3) que aparece con muy poca frecuencia en la LMC. El paciente se encuentra en tratamiento con imatinib (400 mg diarios) desde el inicio de la enfermedad. A los 6 meses no se detectó presencia del gen quimérico BCR-ABL; 2 estudios moleculares posteriores, al año y a los 2 años de tratamiento, resultaron positivos, pero esto no implicó modificación del tratamiento. La evolución favorable del paciente, a pesar de la recaÍda molecular, concuerda con lo esperado descrito en la literatura en relación con la presencia del transcripto b2a3 en la LMC

The case of a patient with chronic myeloid leukemia and atypical BCR-ABL transcript was presented. By using the qualitative analysis of the polymerase chain reaction products and the comparison with the molecular weights of the amplification product from the samples taken from those patients positive to the most frequent rupture points e13a2 (b2a2) and e14a2 (b3a2), it was determined that chimeric gen BCR-ABL of this patient should correspond to transcript e13a3 (b2a3) that rarely occurs in CML. The patient is being treated with Imatinib (400 mg daily) since the onset of his disease. After six months, the chimeric gen BCR-ABL was not detected. Two molecular studies carried out one year and two years after the treatment yielded positive results, but this did not imply any change to the treatment. Despite the molecular relapse, the favorable recovery of the patient agreed with the expected result described in the literature in terms of the presence of transcript b2a3 in CML

Estimation of salivary amylase and total proteins in leukemia patients and its correlation with clinical feature and radiographic finding.

Background: Leukemia is a fatal disease. The oral manifestations of the leukemias occur early in the course of the disease and these oral features can at times act as a diagnostic indicator. Saliva has been used as a diagnostic aid in a number of systemic diseases. Materials and Methods: In our study, samples of unstimulated saliva of 30 leukemia patients who were not on chemotherapy were collected and analyzed for salivary amylase and total protein. The oral manifestations and radiographic changes (OPG) were recorded. The correlation between the oral manifestations and the salivary components (salivary amylase and total protein) was assessed for prognostic significance. Results: In the present study when the mean values of salivary amylase (1280±754 U/ml) and total protein (647.2±320.7 mg%) were compared with that in control subjects. There was a statistically significant difference for amylase levels (P<.05). On intraoral examination the study subjects showed pallor, gingivitis, gingival enlargement, petechiae, and ecchymosis. On the OPG, the radiographic features included generalized rarefaction of bone (20%), thinning of lamina dura (3.4%), generalized alveolar crest bone resorption (30%), thinning of walls of alveolar crypts (6.7%), besides others, e.g., periapical abscess (10%). Conclusions: The saliva of leukemic patients demonstrated obvious changes in composition. A rise in salivary amylase and total protein levels was evident, with the increase in amylase levels being statistically significant.

Influence of late treatment on how chronic myeloid leukemia responds to imatinib

INTRODUCTION: In Brazil, patients with chronic myeloid leukemia (CML) in the chronic phase were not given first-line imatinib treatment until 2008. Therefore, there was a long period of time between diagnosis and the initiation of imatinib therapy for many patients. This study aims to compare the major molecular remission (MMR) rates of early versus late imatinib therapy in chronic phase CML patients. METHODS: Between May 2002 and November 2007, 44 patients with chronic phase CML were treated with second-line imatinib therapy at the Hematology Unit of the Ophir Loyola Hospital (Belém, Pará, Brazil). BCR-ABL transcript levels were measured at approximately six-month intervals using quantitative polymerase chain reaction. RESULTS: The early treatment group presented a 60 percent probability of achieving MMR, while the probability for those patients who received late treatment was 40 percent. The probability of either not achieving MMR within one year of the initiation of imatinib therapy or losing MMR was higher in patients who received late treatment (79 percent), compared with patients who received early treatment (21 percent, odds ratio=5.75, P=0.012). The probability of maintaining MMR at 30 months of treatment was 80 percent in the early treatment group and 44 percent in the late treatment group (P=0.0005). CONCLUSIONS: For CML patients in the chronic phase who were treated with second-line imatinib therapy, the probability of achieving and maintaining MMR was higher in patients who received early treatment compared with those patients for whom the time interval between diagnosis and initiation of imatinib therapy was longer than one year.

Technetium-99m MDP bone scintigraphic findings of hypercalcemia in accelerated phase of chronic myelogenous leukemia

Hypercalcemia in accelerated phase of chronic myelogenous leukemia (CML) is very rare. Its pathogenesis is considered humoral hypercalcemia of malignancies mediated by parathyroid hormone-related protein (PTHrP). In severe hypercalcemia, calcifications in kidneys, skin, vessels, heart, and stomach may occur. Our two cases were admitted because of severe hypercalcemia in accelerated phase of CML. On Tc-99m methylene diphosphonate (MDP) bone scintigraphies, a marked tracer accumulation was seen in the lung, heart, stomach and kidney. We report increased tracer accumulation of multiple organs on Tc-99m MDP bone scintigraphy in two rare hypercalcemic patients with CML.

Los oligonucleotidos antisense potencian la apoptosis inducida por la idarubicina en la linea celular K-562 / Antisense oligonucleotides increase the apoptotic effect of idarubicin in K-562 cell line

La línea celular K-562, portadora del rearreglo bcr/abl de tipo b3a2 es resistente a la apoptosis inducida por inhibidores de topoisomerasa II. Se trataron células de dicha línea con complejos de liposomas catiónicos (DMRIE-DOPE y Dcchol-DOPE) y oligonucleótidos antisense (ODNs AS) dirigidos contra el ARNm bcr/abl de tipo b3a2, y non sense (ODNs NS), en una razón 3:1 lípido/ADN, durante 72 horas, luego se incubaron durante 24 horas con idarubicina (IDA), 0.5 mug/ml, para inducir apoptosis. La misma se evaluó por observación morfológica al microscopio de fluorescencia. Las células tratadas con los conjugados DMRIE-DOPE y Dcchol/DOPE con el ODN AS específico mostraron un mayor porcentaje de apoptosis inducida por IDA (X + DS: 14.74 + 2.07 y 20.43 + 4.58, respectivamente) comparadas con los controles no tratados con ODNs (X + DS: 8.08 + 0.82); (p<0.005). Los datos indican que los ODNs-AS dirigidos contra el ARNm bcr-abl de tipo b3a2 vuelven a las células de la línea K-562 sensibles a la IDA a la concentración mencionada.

Integrin receptors and TGF-Beta expression in chronic myeloid leukemia cells

To understand relationiship between transforming growth factor beta-1 (TGF-ß1) and the integrin profile presented by chronic myeloid leukemia cells, we have studied, using Northen analysis, the expression of TGF-ß1 messenger RNA (TGF-ß mRNA) in myeloid cell lines and in patient with acute myeloid leukemia (AML) and chronic myeloid leukemia (CML). In addition we determined the positivity for alfa4 and alfa5 integrin moleculas in those cell using specific monoclonal antibodies and flow cytometry. CML patients (N=3) presented mean values of alfa4 higher (alfa4: 60 ñ 20 per cent); alfa5: 70 ñ 41 per cent) than AML (N=10) blast cells (alfa4: 25 ñ 23 per cent); alfa5: 18 ñ 16 per cent). Northern analysis revealed an almost four-fold higher expression of TGF-ß mRNA in K562 (derived from a patient with chronic myeloid leukemia) compared to the myeloblastic cell line HL60. The highest TGF-ß mRNA levels were seen in the U937 lineage. CML leukemic cells (N=3) showed high TGF-ß mRNA levels comparable to the levels expressed by K562 which was paralleled by high ß1 integrin mRNA. AML blast cells presented a variable degree of expression of TGF-ß mRNA when compared to HL60. One patient with acute megakaryoblastic leukemia (FAB subtype M7), usually associated with myelofibrosis, presented the highest TGF-ß mRNA levels. We conclude that studing TGF-ß1 and its mechanisms of action will help in understanding fibrosis in leukemic patients, and perhaps to design treatments for such conditions

Alteraciones bioquímicas y citoquímicas de hidrolasas ácidas lisosomales en leucemias / Biochemical and citochemical alterations of lisosomal acid hydrolases in leukemias

La actividad enzimática total de ß-galactosidasa (ß-gal), hexosaminidasa (hex) y fosfatasa ácida (Fac) fue determinada bioquímicamente, tanto en suero como en sobrenadantes de homogenatos celulares de sujetos normales y pacientes portadores de leucemias, empleándose sustratos paranitrofenilados específicos. La actividad de ß-gal en leucemias mieloides, tanto agudas (LMA-M1) como crónicas (LMC), sólo mostró un incremento significativo en sobrenadantes de homogenato celulares, respecto a los valores de neutrófilos normales. En leucemias linfoidales agudas (LLA), como crónicas (LLC), su comportamiento no ofreció variaciones. Tanto los sueros como los sobrenadantes de homogenatos celulares de LMA-M1 y LMC mostraron un franco incremento en la actividad de hex, mientras en LLA y LLC esta actividad no mostró variaciones. La actividad sérica de fosfatasa ácida estuvo incrementada en el 86% de las LMC. En los sobrenadantes de homogenatos celulares de LLA y LLC, esta actividad enzimática se mostró significativamente disminuida respecto de los valores de linfocitos normales. En los tres casos de LMA-M4 analizados, fue observado en el contenido celular niveles elevados de ß-gal, hex y Fac (lo que estaría correlacionado con la presencia de monocitos y/o monoblastos normales, con alto contenido de hidrolasas ácidas). Citoquímicamente fue demostrado en médula ósea y sangre periférica de pacientes con LMA-M1 una ligera o nula actividad de hex, en tanto que en LLA la reacción fue localizada asimétricamente en un polo celular o en gránulos citoplasmáticos. Los resultados encontrados demuestran una gran heterogeneidad en el contenido lisosomal de los diferentes tipos de leucemias

Simplified method for the analysis of cellular karyotype and phenotype in leukemias

The objective of this study was to develop a simplified method for the simultaneous analysis of cellular karyotype and phenotype which would permit the identification of cell origin. We studied 6 patients with AML, 3 with CML (one of which was in blastic transformation) and one ALL. We used a method in which the suspension of bone marrow cells was incubated in TC 199 medium with colchicine and with hypotonic solution formed from glycerol, NaCl, KCl, CaCl2, MgCl2 and sucrose. The slides were prepared from this cell suspension by cytospin and stained for peroxidase, PAS, esterases and iron. The karyotype was studied by direct method and culture. It was possible to relate the cytogenetic marker with cytochemistry characteristics in the same cell in 3 cases, showing the feasibility of cytochemistry techniques in cytogenetical preparations. The best preparations were found through peroxidase. The presence of iron granules allowed identification of erythroblastic lineage in the combined staining. Mitosis with a marker chromosome of leukemic clone in an AML cell with negative peroxidase probably showed a proliferation of more primitive precursor not sufficiently differentiated to show markers