Evolutionarily Conserved Signaling Pathways: Acting in the Shadows of Acute Myelogenous Leukemia’s Genetic Diversity.
Clin Cancer Res. 2015 Jan 15;21(2):240-248
Authors: Heidel FH, Arreba-Tutusaus P, Armstrong SA, Fischer T
Acute myelogenous leukemia stem cells (AML-LSC) give rise to the leukemic bulk population and maintain disease. Relapse can arise from residual LSCs that have distinct sensitivity and dependencies when compared with the AML bulk. AML-LSCs are driven by genetic and epigenomic changes, and these alterations influence prognosis and clonal selection. Therapies targeting these molecular aberrations have been developed and show promising responses in advanced clinical trials; however, so far success with LSCs has been limited. Besides the genetic diversity, AML-LSCs are critically influenced by the microenvironment, and a third crucial aspect has recently come to the fore: A group of evolutionarily conserved signaling pathways such as canonical Wnt signaling, Notch signaling, or the Hedgehog pathway can be essential for maintenance of AML-LSC but may be redundant for normal hematopoietic stem cells. In addition, early reports suggest also regulators of cell polarity may also influence hematopoietic stem cells and AML biology. Interactions between these pathways have been investigated recently and suggest a network of signaling pathways involved in regulation of self-renewal and response to oncogenic stress. Here, we review how recent discoveries on regulation of AML-LSC-relevant evolutionarily conserved pathways may open opportunities for novel treatment approaches eradicating residual disease. Clin Cancer Res; 21(2); 240-8. ©2015 AACR.
PMID: 25593343 [PubMed - as supplied by publisher]
Population pharmacokinetics and individualized dosage prediction of cyclosporine in allogeneic hematopoietic stem cell transplant patients.
Am J Med Sci. 2014 Dec;348(6):448-54
Authors: Xue L, Zhang WW, Ding XL, Zhang JJ, Bao JA, Miao LY
BACKGROUND: Cyclosporine (CsA), a potent immunosuppressive agent used to prevent rejection, is characterized by large individual variability. The purpose of this study was to explore the pharmacokinetic characteristics of CsA and establish a CsA population pharmacokinetic model that could be used for personalized therapy in allogeneic hematopoietic stem cell transplant (allo-HSCT) patients.
METHODS: Clinical data were obtained from 117 allo-HSCT patients. The data analysis was performed using NONMEM software. A first-order conditional estimation with interaction (FOCE-I) method within NONMEM was used to estimate the parameters. The covariates, including demographics, hematological indices, biochemical levels, concurrent drugs, and genetic polymorphisms of CYP3A4, CYP3A5, and ABCB1, were evaluated quantitatively. The stability of the final model was validated by a nonparametric bootstrap procedure.
RESULTS: A total of 1,571 observed concentrations were collected. A 1-compartment model with first-order absorption and elimination adequately described the pharmacokinetics of CsA. The typical values for clearance (CL), volume of distribution (V), and bioavailability were 29.6 L/hr, 605 L, and 0.619, respectively. The interindividual variability of these parameters was 20.4, 66.1, and 30.4%, respectively. The residual error was 31.4% and 23.7 ng/mL. The duration of CsA therapy, hematocrit, antifungal agent administration, triglycerides, and weight were identified as the main covariates that influenced CL, and hematocrit had a significant effect on V. The internal validation showed that the final model was stable and accurate.
CONCLUSIONS: This study established a population pharmacokinetic model of CsA in allo-HSCT patients that could provide the foundation for personalized use of CsA in the clinic.
PMID: 25247760 [PubMed - indexed for MEDLINE]
Long-term imatinib treatment does not cause testicular toxicity in male adolescents with chronic myeloid leukemia and in a juvenile rat model.
Klin Padiatr. 2014 May;226(3):169-74
Authors: Tauer JT, Ulmer A, Glauche I, Jung R, Suttorp M
BACKGROUND: The impact of exposure to the tyrosine kinase inhibitor (TKI) imatinib (IMA) on the male reproductive endocrine system is still discussed controversially. We therefore investigated testosterone (Testo) and inhibin B (InB) in blood serum from male adolescents with chronic myeloid leukemia (CML) under long-term TKI treatment. Also long-term exposure to TKIs was studied in a juvenile rat model.
METHODS: Serum was collected at 3 months intervals from 13 boys (age: 7.8-18.9 years, median: 12.8 years) with CML receiving TKI treatment over 3-58 months (median: 18 months). 4 weeks (w) old male rats were exposed, either chronically or intermittently, via the drinking water to a standard (SD) and a high dose (=2-fold SD) of IMA, dasatinib (DASA), or bosutinib (BOSU) over a 10?w period. Controls received water only. Animals were sacrificed after 2?w (prepubertal), 4?w (pubertal), and 10?w (postpubertal) of exposure. Testo and InB serum levels were measured by ELISA.
RESULTS: Boys exhibited Testo and InB levels within normal age-related reference ranges and no pattern of rising or falling levels during TKI treatment could be observed. In rats, Testo levels under IMA exposure tended to be non-significantly lowered at postpubertal age compared to controls while no significant differences were found under DASA and BOSU exposure. Animals’ InB levels did not significantly differ from controls for all TKIs, at all doses, and by all application schemes tested.
CONCLUSION: With the limitation that the number of individuals tested was rather small, testicular toxicity due to TKI seems unlikely as no alterations of Testo and InB blood levels neither in male adolescent patients nor in rats under long-term TKI exposure was observed.
PMID: 24819387 [PubMed - indexed for MEDLINE]
The Effects of Extending of Co-planarity in a Series of Structurally Relative Polypyridyl Palladium(II) Complexes on DNA-binding and Cytotoxicity Properties.
Iran J Pharm Res. 2014;13(4):1279-94
Authors: Shahraki S, Mansouri-Torshizi H, Sori Nezami Z, Ghahghaei A, Yaghoubi F, Divsalar A, Saboury AA, H Shirazi F
In depth interaction studies between calf thymus deoxyribonucleic acid (CT-DNA) and a series of four structurally relative palladium(II) complexes [Pd(en)(HB)](NO3)2 (a-d), where en is ethylenediamine and heterocyclic base (HB) is 2,2′-bipyridine (bpy, a); 1,10-phenanthroline (phen, b); dipyridoquinoxaline (dpq, c) and dipyridophenazine (dppz, d) (Figure 1), were performed. These studies have been investigated by utilizing the electronic absorption spectroscopy, fluorescence spectra and ethidium bromide (EBr) displacement and gel filtration techniques. a-d complexes cooperatively bind and denature the DNA at low concentrations. Their concentration at midpoint of transition, L1/2, follows the order a >> b > c > d. Also the g, the number of binding sites per 1000 nucleotides, follows the order a >> b ~ c > d. EBr and Scatchard experiments for a-d complexes suggest efficient intercalative binding affinity to CT-DNA giving the order: d > c > b > a. Several binding and thermodynamic parameters are also described. The biological activity of these cationic and water soluble palladium complexes were tested against chronic myelogenous leukemia cell line, K562. b, c and d complexes show cytotoxic concentration (Cc50) values much lower than cisplatin.
PMID: 25587317 [PubMed]
Phenethyl isothiocyanate inhibits growth of human chronic myeloid leukemia K562 cells via reactive oxygen species generation and caspases.
Mol Med Rep. 2014 Jul;10(1):543-9
Authors: Wang Y, Wei S, Wang J, Fang Q, Chai Q
Phenethyl isothiocyanate (PEITC), a potential cancer chemopreventive constituent of cruciferous vegetables, including watercress, has been reported to inhibit cancer cell growth by arresting the cell cycle and inducing apoptosis in various human cancer cell models. However, the role of PEITC in the inhibition of human chronic myeloid leukemia (CML) K562 cell growth and its underlying mechanisms have yet to be elucidated. In the present study, PEITC was found to induce cell death through the induction of reactive oxygen species (ROS) stress and oxidative damage. Heme oxygenase?1 (HO?1), which participates in the development of numerous tumors and the sensitivity of these tumors to chemotherapeutic drugs, plays a protective role by modulating oxidative injury. Therefore, the present study assessed the inhibitory effect of PEITC on K562 cells and whether HO?1 facilitated cell apoptosis and ROS generation. PEITC was found to suppress cell growth and cause apoptosis by promoting Fas and Fas ligand expression, increasing ROS generation and by the successive release of cytochrome c as well as the activation of caspase?9 and caspase?3. PEITC was also combined with the HO?1 inhibitor zinc protoporphyrin IX and the inducer hemin to assess whether HO?1 determines cell survival and ROS generation. The results of the present study suggest that PEITC may be a potential anti?tumor compound for CML therapy, and that HO?1 has a critical function in PEITC?induced apoptosis and ROS generation.
PMID: 24788892 [PubMed - indexed for MEDLINE]
In silico identification of novel kinase inhibitors targeting wild-type and T315I mutant ABL1 from FDA-approved drugs.
Mol Biosyst. 2014 Jun;10(6):1524-37
Authors: Xu HL, Wang ZJ, Liang XM, Li X, Shi Z, Zhou N, Bao JK
The constitutively active fusion protein BCR-ABL1 is the major cause of chronic myeloid leukemia (CML), and selective inhibition of ABL1 is a promising approach for the treatment of CML. Reported drugs worked well in clinical practice, such as imatinib, dasatinib, nilotinib and bosutinib. However, resistance arises due to ABL1 mutation in patients, especially the T315I gate-keeper mutation. Thus, wide spectrum drugs targeting ABL1 are urgently needed. In order to screen potential drugs targeting wild-type ABL1 and T315I mutant ABL1, 1408 FDA approved small molecule drugs were subjected to molecular docking. With subsequent molecular dynamic (MD) simulation and MM/GBSA binding free energy calculation and energy decomposition, we identified chlorhexidine and sorafenib as potential “new use” drugs targeting wild-type ABL1, while nicergoline and plerixafor targeted T315I ABL1. Meanwhile, we also found that residues located in the ATP-binding site and A-loop motif played key roles in drug discovery towards ABL1. These findings may not only serve as a paradigm for the repositioning of existing approved drugs, but also instill new vitality to ABL1-targeted anti-CML therapeutics.
PMID: 24691568 [PubMed - indexed for MEDLINE]
EAPB0503, a novel imidazoquinoxaline derivative, inhibits growth and induces apoptosis in chronic myeloid leukemia cells.
Anticancer Drugs. 2014 Jul;25(6):624-32
Authors: Saliba J, Deleuze-Masquéfa C, Iskandarani A, El Eit R, Hmadi R, Mahon FX, Bazarbachi A, Bonnet PA, Nasr R
Imatinib, the first-generation tyrosine kinase inhibitor, revolutionized the therapeutic management of chronic myeloid leukemia (CML) and is highly effective in inducing remissions and prolonging the survival of CML patients. However, one-third of patients develop intolerance or resistance to treatment, and CML stem cells remain insensitive to this therapy, leading almost inevitably to relapse upon treatment discontinuation. Imidazoquinoxalines are imiquimod derivatives that induce growth inhibition and induction of caspase-dependent apoptosis in melanoma and T-cell lymphoma cells. We investigated the effects of EAPB0203 and EAPB0503, two novel imidazoquinoxaline derivatives, on human CML cell lines and showed that they induced a dose-dependent and time-dependent cell growth inhibition. EAPB0503 proved more potent and induced a specific cell cycle arrest in mitosis in CML cells and direct activation of apoptosis as evidenced by increased pre-G0 population, breakdown of mitochondrial membrane potential, PARP cleavage, and DNA breakage. Interestingly, EAPB0503 decreased BCR-ABL oncoprotein levels. The combination of EAPB0503 with imatinib synergized to inhibit the proliferation of CML cells, and most importantly, EABP0503 inhibited the proliferation of imatinib-resistant CML cells, offering promising therapeutic modalities that would circumvent resistance to tyrosine kinase inhibitors and improve the prognosis of CML.
PMID: 24463483 [PubMed - indexed for MEDLINE]
Health-related quality of life of patients with newly diagnosed chronic myeloid leukemia treated with allogeneic hematopoietic SCT versus imatinib.
Bone Marrow Transplant. 2014 Apr;49(4):576-80
Authors: Mo XD, Jiang Q, Xu LP, Liu DH, Liu KY, Jiang B, Jiang H, Chen H, Chen YH, Zhang XH, Han W, Wang Y, Huang XJ
To evaluate and compare the health-related quality of life (HRQOL) of patients with newly diagnosed CML in the first chronic phase (CML-CP1) receiving HLA-identical sibling donor (ISD) hematopoietic SCT (HSCT) or imatinib, a cross-sectional study that was part of a prospective cohort study at the Institute of Hematology, Peking University was performed. A total of 222 patients including 126 and 96 in the imatinib and ISD HSCT groups, respectively, were enrolled. HRQOL was measured using the Medical Outcomes Study 36-Item Short-Form Health Survey. The ISD HSCT group functioned significantly better on the role-physical functioning and mental health subscales, as well as the mental component summary (MCS) than the imatinib group. HRQOL was generally comparable to groups in the young population. Multivariate analysis showed that white blood cell count ? 30 × 10(9)/L and plts count ? 450 × 10(9)/L were the major adverse factors affecting HRQOL in long-term survivors. Imatinib therapy was also an adverse factor affecting the MCS (odds ratio=1.7, P=0.032). Thus, long-term CML-CP1 survivors receiving ISD HSCT can attain desirable HRQOL comparable to or better than that of patients receiving imatinib.
PMID: 24442252 [PubMed - indexed for MEDLINE]
Squamous cell carcinoma in a chronic myelogenous leukemia patient treated with imatinib mesylate.
J Dermatol. 2015 Jan 12;
Authors: Fujii M, Iwasaki T, Takahashi I, Kishiyama K, Honma M, Takahashi H, Ishida-Yamamoto A, Iizuka H
PMID: 25580575 [PubMed - as supplied by publisher]
Autologous serum eye drops for severe dry eye syndrome in a patient with chronic graft-versus-host disease: a case report.
Int J Pharm Compd. 2014 Sep-Oct;18(5):370-7
Authors: Mixon B, Mixon J, Isbey EK, Sprinkle S
We present the case of a 49-year-old woman with severe dry eye syndrome caused by chronic graft-versus-host disease that developed after an allogeneic hematopoietic transplant to treat acute myelogenous leukemia. After the use of commercially manufactured products for the treatment of dry eye failed to relieve her photosensitivity, blurred. vision, and severe bilateral ocular pain, she benefitted significantly from therapy with compounded autologous serum eye drops. Comments from that patient are included in this report, as are a formulation for the preparation of autologous eye drops and suggestions for their safe and effective use.
PMID: 25577885 [PubMed - in process]
[Allo-geneic hematopoietic stem cell transplantation in treatment with T315I mutation of chronic myelogenous leukemia].
Zhonghua Yi Xue Za Zhi. 2014 Nov;94(40):3150-3
Authors: Wang L, Liu H, Zheng C, Tang B, Zhu X, Yao W, Zhang L, Sun Z
OBJECTIVE: To explore the therapeutic efficacy of allo-geneic hematopoietic stem cell transplantation (allo-HSCT) for chronic myelogenous leukemia (CML) patients with T315I mutation.
METHODS: Retrospective analyses were conducted for 4 patients with T315I mutation of CML undergoing allo-HSCT from June 2012 to January 2014, including 2 cases in acceleration phase and 2 in chronic phase. There were 2 males and 2 females with ages from 26 to 45 years. Two patients received HLA-matched sibling allo-geneic peripheral blood stem cell transplantation (allo-PBSCT) while another 2 unrelated cord blood stem cell transplantation (UCBT). No splenomegaly was found before transplantation. One case had F317L mutation. All of them were treated with imatinib before transplantation. And the time from medication to T315I mutation was 20-35 months. All of them were conditioned with myeloablative regimen and received a combination of cyclosporine A (CsA) and mycophenolate mofetil (MMF) for preventing graft-versus-host disease (GVHD).
RESULTS: Myeloid implantation was achieved in all of them. The time of absolute neutrophil count (ANC) ? 0.5×10(9)/L were 10-28 days. One patient whose platelet was not implanted died from severe pulmonary infection at Day 88 post-transplantation. For 3 patients, platelet ? 20×10(9)/L were 15-33 days. But the marrow short tandem repeat (STR)-PCR was 100% donor type at the time of 30 days post-transplantation in all patients. One case of UCBT developed pre-implantation immune response syndrome (PES) and one acute GVHD of gradeI at Day 12 after allo-PBSCT. However both were controlled after treatment with methylprednisolone. And 1/3 evaluatable patients developed chronic GVHD. BCR/ABL transcript was detected by qualitative PCR after transplantation. And all BCR/ABL fusion genes turned negative after 30 days of transplantation. Up to the follow-up endpoint, there was no relapse except for one mortality. And the time of disease-free survival was 133, 248 and 704 days respectively.
CONCLUSIONS: Allo-HSCT is currently the optimal treatment for T315I mutation of CML. And umbilical cord blood is an ideal donor for those patients without HLA-matched sibling donor.
PMID: 25573310 [PubMed - in process]
Sensitivity of hematological malignancies to graft-versus-host effects: an EBMT megafile analysis.
Leukemia. 2014 Nov;28(11):2235-40
Authors: Stern M, de Wreede LC, Brand R, van Biezen A, Dreger P, Mohty M, de Witte TM, Kröger N, Ruutu T
After allogeneic stem cell transplantation, graft-versus-host disease (GvHD) occurs through recognition of histocompatibility mismatches by donor T lymphocytes. The same mechanism operates in eliminating malignant cells (the graft-versus-tumor or GvT effect). We hypothesized that comparing the correlation between GvHD and relapse might provide a surrogate marker for the susceptibility of diseases to allo-immune effects. We studied 48?111 first allogeneic transplants performed between 1998 and 2007. In chronic myeloid leukemia (CML), the relapse risk declined clearly and proportionally to severity of acute and chronic GvHD. Acute lymphoblastic leukemia and BCR-ABL-negative myeloproliferative neoplasias were comparably sensitive to GvHD as CML, whereas myelodysplastic syndromes and lymphoproliferative disorders showed intermediate sensitivity. GvHD was only associated with modest reductions in relapse risk in acute myeloid leukemia (AML) and plasma cell disorders (PCDs). Except for PCD, hazard rates for relapse decreased to almost 0 at 48 months of follow-up in all diseases. These data confirm observations of potent GvT effects associated with GvHD. The strength of the GvHD/GvT correlation differs significantly between hematological malignancies. The parallel drop of relapse rates in different diseases despite differences in GvHD/GvT ratios suggests that GvT effects might operate in the absence of GvHD, particularly in AML.
PMID: 24781016 [PubMed - indexed for MEDLINE]
Low expression of Abelson interactor-1 is linked to acquired drug resistance in Bcr-Abl-induced leukemia.
Leukemia. 2014 Nov;28(11):2165-77
Authors: Chorzalska A, Salloum I, Shafqat H, Khan S, Marjon P, Treaba D, Schorl C, Morgan J, Bryke CR, Falanga V, Zhao TC, Reagan J, Winer E, Olszewski AJ, Al-Homsi AS, Kouttab N, Dubielecka PM
The basis for persistence of leukemic stem cells in the bone marrow microenvironment remains poorly understood. We present evidence that signaling cross-talk between ?4 integrin and Abelson interactor-1 (Abi-1) is involved in the acquisition of an anchorage-dependent phenotype and drug resistance in Bcr-Abl-positive leukemia cells. Comparison of Abi-1 (ABI-1) and ?4 integrin (ITGA4) gene expression in relapsing Bcr-Abl-positive CD34+progenitor cells demonstrated a reduction in Abi-1 and an increase in ?4 integrin mRNA in the absence of Bcr-Abl mutations. This inverse correlation between Abi-1 and ?4 integrin expression, as well as linkage to elevated phospho-Akt and phospho-Erk signaling, was confirmed in imatinib mesylate -resistant leukemic cells. These results indicate that the ?4-Abi-1 signaling pathway may mediate acquisition of the drug-resistant phenotype of leukemic cells.
PMID: 24699303 [PubMed - indexed for MEDLINE]
Plasma and intracellular imatinib concentrations in patients with chronic myeloid leukemia.
Ther Drug Monit. 2014 Jun;36(3):410-2
Authors: De Francia S, D?Avolio A, Ariaudo A, Pirro E, Piccione F, Simiele M, Fava C, Calcagno A, Di Perri G, Saglio G
BACKGROUND: Imatinib (Gleevec, STI-571), a 2-phenylaminopyrimidine-type competitive inhibitor of Bcr-Abl kinase, is the current frontline therapy for patients with chronic myeloid leukemia, and it induces durable responses and prolonging event-free and progression-free survival. Monitoring imatinib trough plasma concentration is a simple and rapid way to determine if the drug exposure exceeds the clinical efficacy threshold (1 mcg/mL). Because the target enzyme is located within cells, adequate drug intracellular concentrations are needed to inhibit its function.
METHODS: Chromatographic methods were used to quantify imatinib concentrations in both plasma and peripheral blood mononuclear cells collected from adult patients with chronic myeloid leukemia at the Department of Hematology. Samples were collected at steady state, and trough concentrations (24 ± 2 hours after last drug intake) were evaluated. Associations between variables were tested using the Pearson test; results are presented as mean (±SD).
RESULTS: Thirty-five samples from 24 patients were collected; patients were mainly men (16, 66.7%), aged 60 years old (±13.1) and with a body mass index of 24.8 (±4.4). A positive and significant correlation (r = 0.203; P = 0.027) was found between imatinib plasma and intracellular concentrations.
CONCLUSIONS: The observed correlation between plasma and intracellular imatinib concentrations suggests that they may be used to monitor drug exposure and treatment efficacy.
PMID: 24342895 [PubMed - indexed for MEDLINE]
Absence of EZH2 gene mutation in chronic myeloid leukemia patients in blast crisis.
Asian Pac J Cancer Prev. 2013;14(5):3375-6
Authors: Chen HY, Yao H, Wu LY, Liu CJ, Zhu JQ, Liu CH, Wang W, Dong SS, Ping NN, Chen SN, Sun M
PMID: 23803132 [PubMed - indexed for MEDLINE]
Two consecutive twin and a singleton pregnancy in a patient with chronic myeloid leukemia.
J Exp Ther Oncol. 2014;10(4):259-61
Authors: Halim TA, Nabeel N
Consecutive multiple pregnancies with Chronic myeloid leukemia is a rare event and little is known about its prevalence and management with or without chemotherapy. We present a case of three consecutive pregnancies in a woman with CML, two of which were multiple pregnancies.
PMID: 25509979 [PubMed - indexed for MEDLINE]
Granulocyte Colony-stimulating Factor-primed Bone Marrow: An Excellent Stem-cell Source for Transplantation in Acute Myelocytic Leukemia and Chronic Myelocytic Leukemia.
Chin Med J (Engl). 2015 Jan;128(1):20-4
Authors: Li Y, Jiang M, Xu C, Chen J, Li B, Wang J, Hu J, Ning H, Chen H, Chen S, Hu L
BACKGROUND: Steady-state bone marrow (SS-BM) and granulocyte colony-stimulating growth factor-primed BM/peripheral blood stem-cell (G-BM/G-PBSC) are the main stem-cell sources used in allogeneic hematopoietic stem-cell transplantation. Here, we evaluated the treatment effects of SS-BM and G-BM/G-PBSC in human leucocyte antigen (HLA)-identical sibling transplantation.
METHODS: A total of 226 patients (acute myelogenous leukemia-complete remission 1, chronic myelogenous leukemia-chronic phase 1) received SS-BM, G-BM, or G-PBSC from an HLA-identical sibling. Clinical outcomes (graft-versus-host disease [GVHD], overall survival, transplant-related mortality [TRM], and leukemia-free survival [LFS]) were analyzed.
RESULTS: When compared to SS-BM, G-BM gave faster recovery time to neutrophil or platelet (P < 0.05). Incidence of grade III-IV acute GVHD and extensive chronic GVHD (cGVHD) was lower than seen with SS-BM (P < 0.05) and similar to G-PBSC. Although the incidence of cGVHD in the G-BM group was similar to SS-BM, both were lower than G-PBSC (P < 0.05). G-BM and G-PBSC exhibited similar survival, LFS, and TRM, but were significantly different from SS-BM (P < 0.05). There were no significant differences in leukemia relapse rates among the groups (P > 0.05).
CONCLUSIONS: G-CSF-primed bone marrow shared the advantages of G-PBSC and SS-BM. We conclude that G-BM is an excellent stem-cell source that may be preferable to G-PBSC or SS-BM in patients receiving HLA-identical sibling hematopoietic stem-cell transplantation.
PMID: 25563308 [PubMed - in process]
A multiplex snapback primer system for the enrichment and detection of JAK2 V617F and MPL W515L/K mutations in Philadelphia-negative myeloproliferative neoplasms.
Biomed Res Int. 2014;2014:458457
Authors: Wu Z, Zhang Y, Zhang X, Xu X, Kang Z, Li S, Zhang C, Su B, Guan M
A multiplex snapback primer system was developed for the simultaneous detection of JAK2 V617F and MPL W515L/K mutations in Philadelphia chromosome- (Ph-) negative myeloproliferative neoplasms (MPNs). The multiplex system comprises two snapback versus limiting primer sets for JAK2 and MPL mutation enrichment and detection, respectively. Linear-After exponential (LATE) PCR strategy was employed for the primer design to maximize the amplification efficiency of the system. Low ionic strength buffer and rapid PCR protocol allowed for selective amplification of the mutant alleles. Amplification products were analyzed by melting curve analysis for mutation identification. The multiplex system archived 0.1% mutation load sensitivity and <5% coefficient of variation inter-/intra-assay reproducibility. 120 clinical samples were tested by the multiplex snapback primer assay, and verified with amplification refractory system (ARMS), quantitative PCR (qPCR) and Sanger sequencing method. The multiplex system, with a favored versatility, provided the molecular diagnosis of Ph-negative MPNs with a suitable implement and simplified the genetic test process.
PMID: 24729973 [PubMed - indexed for MEDLINE]
Concise review: cancer cells escape from oncogene addiction: understanding the mechanisms behind treatment failure for more effective targeting.
Stem Cells. 2014 Jun;32(6):1373-9
Authors: Pellicano F, Mukherjee L, Holyoake TL
Oncogene addiction describes the dependence of some cancers on one or a few genes for their survival. Inhibition of the corresponding oncoproteins can lead to dramatic responses. However, in some cases, such as chronic myeloid leukemia (CML), a disease characterized by the presence of the abnormal fusion tyrosine kinase BCR-ABL, cancer stem cells may never acquire addiction to the oncogene that drives disease development. The suggested mechanism(s) for treatment failure include a quiescent stem cell population capable of reinstating disease, high levels of oncoprotein expression, or acquired mutations in the oncogene. In this review, we discuss the evidence for oncogene addiction in several solid tumors and their potential escape mechanism(s) with a particular focus on CML stem cells.
PMID: 24520002 [PubMed - indexed for MEDLINE]
ApoptomiRs expression modulated by BCR-ABL is linked to CML progression and imatinib resistance.
Blood Cells Mol Dis. 2014 Jun-Aug;53(1-2):47-55
Authors: Ferreira AF, Moura LG, Tojal I, Ambrósio L, Pinto-Simões B, Hamerschlak N, Calin GA, Ivan C, Covas DT, Kashima S, Castro FA
BACKGROUND: Chronic myeloid leukemia (CML) is a myeloproliferative disease characterized by the presence of Philadelphia chromosome (Ph) leading to expression of a BCR-ABL1 fusion oncogene. The BCR-ABL protein has a constitutive tyrosine kinase activity which is responsible for CML pathogenesis by promoting cell apoptosis resistance; however, the cellular and molecular mechanisms associated with BCR-ABL expression and apoptosis impairment in CML leukemic cells have not been fully elucidated.
METHODS: This study evaluated apoptomiRs and their predicted apoptotic genes in BCR-ABL(+) cells from patients in different phases of CML treated with tyrosine kinase inhibitor (TKI) according to their imatinib (IM) response by qPCR. Phosphotyrosine and c-ABL expressions in HL-60.BCR-ABL cells treated with TKI were done by Western blot.
RESULTS: We found that dasatinib (DAS) modulated miR-let-7d, miR-let-7e, miR-15a, miR-16, miR-21, miR-130a and miR-142-3p expressions while IM modulated miR-15a and miR-130a levels. miR-16, miR-130a and miR-145 expressions were modulated by nilotinib (NIL). We observed higher miR-15a, miR-130b and miR-145; and lower miR-16, miR-26a and miR-146a expressions in CML-CP in comparison with controls. CML-AP patients showed low miR-let-7d, miR-15a, miR-16, miR-29c, miR-142-3p, miR-145, and miR-146a levels in comparison with CML-CP. We noted that the miR-26a, miR-29c, miR-130b and miR-146a expressions were downregulated in IM resistant patients in comparison with IM responsive patients.
CONCLUSIONS: This study showed the modulation of apoptomiRs by BCR-ABL kinase activity and the deregulation of apoptomiRs and their predicted apoptotic target genes in different CML phases and after treatment with TK inhibitors. ApoptomiRs may be involved in the BCR-ABL(+) cell apoptosis regulation.
PMID: 24629639 [PubMed - indexed for MEDLINE]