Mutated genes and driver pathways involved in myelodysplastic syndromes-a transcriptome sequencing based approach.
Mol Biosyst. 2015 May 26;
Authors: Liu L, Wang H, Wen J, Tseng CE, Zu Y, Chang CC, Zhou X
Myelodysplastic syndromes are a heterogeneous group of clonal disorders of hematopoietic progenitors and have potentiality to progress into acute myelogenous leukemia. Development of effective treatments has been impeded by limited insight into pathogenic pathways. In this study, we applied RNA-seq technology to study the transcriptome on 20 MDS patients and 5 age-matched controls, and developed a pipeline for analyzing this data. After analysis, we identified 38 mutated genes contributing to MDS pathogenesis. 37 out of 38 genes have not been reported previously, suggesting our pipeline is critical for identifying novel mutated genes in MDS. The most recurrent mutation happened in gene IFRD1, which involved 30% of patient samples. Biological relationships among these mutated genes were mined using Ingenuity Pathway Analysis, and the results demonstrated that top two networks with highest scores were highly associated with cancer and hematological diseases, indicating that the mutated genes identified by our method were highly relevant to MDS. We then integrated the pathways in KEGG database and the identified mutated genes using our novel rule-based mutated driver pathway scoring approach for detecting mutated driver pathways. The results indicated two mutated driver pathways are important for the pathogenesis of MDS: pathway in cancer and in regulation of actin cytoskeleton. The latter, which likely contributes to the hallmark morphologic dysplasia observed in MDS, has not been reported, to the best of our knowledge. These results provide us new insights into the pathogenesis of MDS, which, in turn, may lead to novel therapeutics for this disease.
PMID: 26010722 [PubMed - as supplied by publisher]
Changing the cost of care for chronic myeloid leukemia: the availability of generic imatinib in the USA and the EU.
Ann Hematol. 2015 Apr;94 Suppl 2:S249-57
Authors: Conti RM, Padula WV, Larson RA
Imatinib is an oral tyrosine kinase inhibitor and considered to be the most successful targeted anti-cancer agent yet developed given its substantial efficacy in treating chronic myeloid leukemia (CML) and other malignant diseases. In the USA and the European Union (EU), Novartis’ composition of matter patent on imatinib will expire in 2016. The potential impact on health system spending levels for CML after generic imatinib becomes available is the subject of significant interest among stakeholders. The extent of the potential savings largely depends on whether and to what extent prices decline and use stays the same or even increases. These are also empirical questions since the likely spending implications following generic imatinib’s availability are predicated on multiple factors: physicians’ willingness to prescribe generic imatinib, molecule characteristics, and health system priorities. This article discusses each of these issues in turn. We then review their implications for the development of country-specific cost-effectiveness models to predict the implications for cost and quality of care from generic imatinib.
PMID: 25814091 [PubMed - indexed for MEDLINE]
Epidemiology of chronic myeloid leukaemia: an update.
Ann Hematol. 2015 Apr;94 Suppl 2:S241-7
Authors: Höglund M, Sandin F, Simonsson B
National and regional population-based registries are, provided diagnostic accuracy and full coverage of the target population, indispensible tools for epidemiological research. Chronic myeloid leukaemia (CML) registries with more comprehensive reporting may also provide complementary data on treatment outcome to those obtained from clinical trials. Reports from several European CML registries consistently show a crude annual incidence of 0.7-1.0/100,000, a median age at diagnosis of 57-60 years and a male/female ratio of 1.2-1.7. The incidence of CML has been stable over time. Worldwide, variations in the reported incidence of CML may be due to methodological issues, but a true difference between different geographical areas and/or ethnical subgroups cannot be excluded. The prevalence of CML is not well known but has been estimated to be 10-12/100,000 inhabitants with a steady increase due to the dramatic improvement in survival of these patients. In recent population-based studies, CML patients have an overall survival that is comparable to that shown in large clinical trials, though relative survival in patients >70 years is still decreased. The importance of socio-economic factors and health-care setting for outcome and the possible increased risk of secondary cancer in CML are areas of ongoing research.
PMID: 25814090 [PubMed - indexed for MEDLINE]
Response-related predictors of survival in CML.
Ann Hematol. 2015 Apr;94 Suppl 2:S227-39
Authors: Hanfstein B, Müller MC, Hochhaus A
The assessment of response to tyrosine kinase inhibitor (TKI) treatment in chronic myeloid leukemia (CML) does not only reflect tumor burden at a given time but has been shown to be linked to long-term survival outcomes as well. Therefore, the quantification of molecular or cytogenetic response as early as 3 months on treatment allows a prognostic stratification of a patient’s individual risk. With competing TKI regimens available, a timely switch of treatment can be considered if unfavorable outcome has to be expected due to early response failure. Numerous studies have demonstrated the association of long-term outcome with early response for first-line treatment with imatinib, with second-generation TKI and for second-line TKI treatment as well.
PMID: 25814089 [PubMed - indexed for MEDLINE]
Molecular monitoring of chronic myeloid leukemia: principles and interlaboratory standardization.
Ann Hematol. 2015 Apr;94 Suppl 2:S219-25
Authors: Cross NC, Hochhaus A, Müller MC
Serial quantification of BCR-ABL1 messenger RNA (mRNA) is an important therapeutic indicator for patients with chronic myeloid leukemia, but historically, there has been substantial variation in results reported by different laboratories. To help improve the comparability of results, an international scale (IS) for BCR-ABL1 was proposed which is being implemented by testing laboratories worldwide. This is being achieved most commonly by the derivation of laboratory-specific conversion factors, but increasingly by the use of kits or reagents that are calibrated to the first World Health Organization International Genetic Reference Panel for quantitation of BCR-ABL1 mRNA. Recent attention has focused on the need to define and validate levels of deeper molecular response (MR) within the context of the IS. While there has been substantial progress in the alignment of results, BCR-ABL1 measurement is technically challenging and standardization is an ongoing process.
PMID: 25814088 [PubMed - indexed for MEDLINE]
Prognostic scores for patients with chronic myeloid leukemia under particular consideration of competing causes of death.
Ann Hematol. 2015 Apr;94 Suppl 2:S209-18
Authors: Pfirrmann M, Lauseker M, Hoffmann VS, Hasford J
Nowadays in many fields of medicine, prognostic scores are used to predict the outcome for individual patients. In chronic myeloid leukemia (CML), the Sokal, the Euro, and the EUTOS score are established prognostic scores which were addressed by the CML management recommendations of the European LeukemiaNet. This review provides a general definition of prognostic scores and explains their meaning. Main differences between the Sokal, the Euro, and the EUTOS score are highlighted. Due to the therapeutic success of tyrosine kinase inhibitors, the proportion of patients with causes of death unrelated to CML is growing. To assess the potential of a drug to prevent dying of CML, causes of death unrelated to CML need to be considered as competing risks. Supported by data of patients randomized to imatinib-based treatments within the German CML study IV, this review also explores the prognostic performance of the established scores if the primary event is death due to CML only and explains the implicit statistical particularities when treating other causes of death as competing risks. In the presence of competing risks, the application of both the cause-specific hazard model and the subdistribution hazard model is recommended when investigating the influence of prognostic factors on the event of interest. Another purpose of this work is to foster the ability of hematologists to interpret the outcome of a cause-specific hazard and a subdistribution hazard model and to understand the differences between them.
PMID: 25814087 [PubMed - indexed for MEDLINE]
The interferon-alpha revival in CML.
Ann Hematol. 2015 Apr;94 Suppl 2:S195-207
Authors: Talpaz M, Mercer J, Hehlmann R
Interferon-alpha (IFN?) was once the standard of frontline treatment for chronic myeloid leukemia (CML). Its pleiotropic mechanism of action in CML includes immune activation and specific targeting of CML stem cells. Early studies of IFN? in CML demonstrated that patients in chronic phase could attain extremely stable remissions, which correlated with long-term survival. Some patients even sustained their remission after discontinuing therapy, but the mechanism underlying this phenomenon is not well understood. Today, BCR-ABL tyrosine kinase inhibitors (TKIs), such as imatinib, induce remarkable responses in CML patients and have become the mainstay of CML therapy. Although TKIs target the pathogenic BCR-ABL protein in CML, they cannot fully eradicate CML stem cells. Some of the clinical trials testing IFN? plus imatinib combination therapy suggest that addition of IFN? increases the speed and rate of responses with imatinib therapy. However, the undesirable side effects of IFN? can make this therapy difficult to deliver, and the optimal therapeutic window for using IFN? in combination therapy is unknown. Further studies are needed to clarify the best niche for IFN? use in CML.
PMID: 25814086 [PubMed - indexed for MEDLINE]
Discontinuation of tyrosine kinase therapy in CML.
Ann Hematol. 2015 Apr;94 Suppl 2:S187-93
Authors: Mahon FX
Over the past decade, a broad array of drugs designed to selectively inhibit protein tyrosine kinases (tyrosine kinase inhibitors or TKIs) have emerged as novel therapies for cancer patients. Chronic myeloid leukemia (CML) is one of the best examples of successful targeted therapy with a TKI. The overall survival of CML patients who respond to treatment is close to that of the healthy population. The response in many patients is so profound that it is possible to consider stopping their treatment and with time, the number of patients in this group has increased to the point where the issue of treatment cessation has become of utmost importance. This has led to the development of a new concept in the evaluation of CML entitled treatment-free remission. It will be the criterion to evaluate the success of future clinical trials, especially if we want to improve the management of the disease to the point where we can claim to have cured CML.
PMID: 25814085 [PubMed - indexed for MEDLINE]
The role of hematopoietic stem cell transplantation in chronic myeloid leukemia.
Ann Hematol. 2015 Apr;94 Suppl 2:S177-86
Authors: Gratwohl A, Baldomero H, Passweg J
Allogeneic hematopoietic stem cell transplantation (HSCT) is currently recommended as 2nd or 3rd line therapy for patients with chronic myeloid leukemia (CML) in first chronic phase or as salvage for patients with very advanced disease. As a consequence, numbers of HSCT in chronic phase have dropped significantly since the introduction of tyrosine kinase inhibitors (TKI), numbers of transplants in advanced disease to a lesser extent. These current recommendations consider primarily disease risk, defined as failure of TKI therapy; they might need to be adapted. We propose a more balanced appraisal of HSCT for individual patients which should include disease risk, transplant risk, and macroeconomic aspects. HSCT should be integrated into the treatment algorithms from diagnosis and be considered very early at first TKI failure for patients with high disease but low transplant risk. For patients with very advanced disease and high transplant risk in contrast, HSCT might only be recommended in a restricted research setting.
PMID: 25814084 [PubMed - indexed for MEDLINE]
Managing pregnancy in chronic myeloid leukaemia.
Ann Hematol. 2015 Apr;94 Suppl 2:S167-76
Authors: Palani R, Milojkovic D, Apperley JF
Over the past decade, we have witnessed significant advances in knowledge of the biology and treatment of chronic myeloid leukaemia (CML). The development of molecular-targeted therapy with tyrosine kinase inhibitors (TKIs) has fundamentally changed the outcome of this disease. Treatment with TKIs is now the standard of care in patients with CML and has dramatically improved long-term survival in the majority of patients. Patients who achieve major molecular response (MMR) after 2 years of treatment with imatinib have survival rates comparable to those of the general population. The success of TKIs has led to durable molecular response and possibility of normal life expectancies, such that it is now timely to address quality of life aspects such as fertility, pregnancy and family planning. Pregnancy in CML presents specific management and therapeutic challenges for the patient and the physician. Despite the recent treatment advances, we still have limited data on the safety of TKIs in pregnancy and its effect on fertility. However, there is a cause for concern and heightened awareness following the occurrence of a constellation of rare congenital malformations and spontaneous abortions in association with imatinib therapy. When a patient becomes pregnant whilst receiving TKI therapy, the difficulty lies in balancing the risk to the foetus of continuing therapy versus the risk to the patient of treatment interruption and potentially losing optimal disease response. All couples should be counselled on the risks associated with pregnancy whilst receiving TKI therapy. This is an essential aspect in patient care and frequently not emphasized enough by physicians. At the time of diagnosis, fertility preservation should be discussed with both male and female patients of childbearing potential. They should be made aware of fertility options which are available such as semen cryopreservation, ovarian or oocyte retrieval and storage and embryo cryopreservation in view of the potential detrimental effect of TKIs on fertility and gonadal function. The recommendation given to patients planning pregnancy differs according to their disease response to TKI therapy, which is the most important prognostic factor in CML.
PMID: 25814083 [PubMed - indexed for MEDLINE]
Management of chronic myeloid leukemia in blast crisis.
Ann Hematol. 2015 Apr;94 Suppl 2:S159-65
Authors: Saußele S, Silver RT
Due to the high efficacy of BCR-ABL tyrosine kinase inhibition (TKI) in chronic phase (CP) chronic myeloid leukemia (CML), the frequency of blast crisis (BC) is greatly reduced compared to the pre-TKI era. However, TKI treatment of BC has only marginally improved the number of favorable responses, including remissions, which for the most part have only been transitory. Occasionally, they provide a therapeutic window to perform an allogeneic stem cell transplantation (allo-SCT). The challenge remains to improve management of BC with the limited options available. We review and summarize articles pertaining to the treatment of BC CML published after 2002. Additionally, we will discuss whether there is a need for a new definition of BC and/or treatment failure.
PMID: 25814082 [PubMed - indexed for MEDLINE]
Management of adverse events associated with tyrosine kinase inhibitors in chronic myeloid leukemia.
Ann Hematol. 2015 Apr;94 Suppl 2:S149-58
Authors: Rea D
Tyrosine kinase inhibitors (TKIs) targeting the breakpoint cluster region-Abelson 1 (BCR-ABL1) oncoprotein represent an outstanding progress in chronic myeloid leukemia (CML), and long-term survival has become a reality. However, the majority of patients need to be treated during their entire life span; thus, outcome does not solely depend on treatment efficacy but also on how well therapy is tolerated. TKIs have an overall favorable safety profile in clinical practice. Although many patients may encounter adverse events, these usually occur early after treatment initiation, are mild to moderate in intensity and resolve spontaneously, or are easily controlled with adequate supportive care. Whenever treatment interruption is necessary, re-exposition to the same TKI or switch to an alternative TKI is successful in the majority of the cases. However, long-term safety issues have not been fully elucidated at present, especially for new-generation TKIs. Recent evidence has emerged that these new agents may sometimes impinge on vital organs such as the heart and lung in an irreversible fashion especially when comorbidities are present; thus, decision regarding of which TKI should be used must take into account disease-related, TKI-related, and patient-related variables. The purpose of this article is to provide an up-to-date review of common adverse events associated with TKIs and how these events may be optimally managed.
PMID: 25814081 [PubMed - indexed for MEDLINE]
A review of the European LeukemiaNet recommendations for the management of CML.
Ann Hematol. 2015 Apr;94 Suppl 2:S141-7
Authors: Baccarani M, Castagnetti F, Gugliotta G, Rosti G
Several guidelines and recommendations on the management of chronic myeloid leukemia (CML) have been prepared by several scientific societies. The European LeukemiaNet (ELN) appointed a panel of experts who submitted their recommendations to peer-reviewed scientific journals in 2006, 2009, and 2013. Here, we make a critical review of the last, 2013, ELN recommendations, concerning the use of the five available tyrosine kinase inhibitors (TKIs), the evaluation of cytogenetic and molecular response, and the strategy of treatment. Three TKIs (imatinib, nilotinib, dasatinib) are recommended first-line. Bosutinib and ponatinib are available second-line; ponatinib is particularly indicated in case of the T315I mutation. Achieving an optimal response, not only for survival but also for a deeper, stable, treatment-free remission, requires a BCR-ABL transcripts level ? 10 % at 3 months, ? 1 % at 6 months, ? 0.1 % at 1 year, and ? 0.01 % later on. Molecular monitoring must include mutational analysis in every case of failure. A successful treatment of accelerated and blastic phase requires TKIs, and in many cases also allogeneic stem cell transplantation.
PMID: 25814080 [PubMed - indexed for MEDLINE]
Natural course and biology of CML.
Ann Hematol. 2015 Apr;94 Suppl 2:S107-21
Authors: Chereda B, Melo JV
Chronic myeloid leukaemia (CML) is a myeloproliferative disorder arising in the haemopoietic stem cell (HSC) compartment. This disease is characterised by a reciprocal t(9;22) chromosomal translocation, resulting in the formation of the Philadelphia (Ph) chromosome containing the BCR-ABL1 gene. As such, diagnosis and monitoring of disease involves detection of BCR-ABL1. It is the BCR-ABL1 protein, in particular its constitutively active tyrosine kinase activity, that forges the pathogenesis of CML. This aberrant kinase signalling activates downstream targets that reprogram the cell to cause uncontrolled proliferation and results in myeloid hyperplasia and ‘indolent’ symptoms of chronic phase (CP) CML. Without successful intervention, the disease will progress into blast crisis (BC), resembling an acute leukaemia. This advanced disease stage takes on an aggressive phenotype and is almost always fatal. The cell biology of CML is also centred on BCR-ABL1. The presence of BCR-ABL1 can explain virtually all the cellular features of the leukaemia (enhanced cell growth, inhibition of apoptosis, altered cell adhesion, growth factor independence, impaired genomic surveillance and differentiation). This article provides an overview of the clinical and cell biology of CML, and highlights key findings and unanswered questions essential for understanding this disease.
PMID: 25814077 [PubMed - indexed for MEDLINE]
CML–Where do we stand in 2015?
Ann Hematol. 2015 Apr;94 Suppl 2:S103-5
Authors: Hehlmann R
PMID: 25814076 [PubMed - indexed for MEDLINE]
Doxycycline inhibits leukemic cell migration via inhibition of matrix metalloproteinases and phosphorylation of focal adhesion kinase.
Mol Med Rep. 2015 May 25;
Authors: Wang C, Xiang R, Zhang X, Chen Y
Doxycycline, a tetracycline-based antibiotic, has been reported to attenuate melanoma cell migration through inhibiting the focal adhesion kinase (FAK) signaling pathway. However, it remains to be elucidated whether doxycycline exerts this effect on leukemia cell migration. The present study aimed to examine the role of doxycycline in leukemia cell migration. The invasion capacities of the human leukemia cell lines KG1a (acute myelogenous leukemia) and K562 (chronic myelogenous leukemia) were evaluated using Matrigel® matrix?coated Transwell® chamber assays; leukemic cell lines treated with doxycycline (1 µg/ml) or anti??1?integrin antibodies were added to the upper chamber, while untreated cells were included as controls. Reverse transcription quantitative polymerase chain reaction was performed in order to further understand the influence of doxycycline treatment on the expression of FAK and gelatinases in the KG1a and K562 leukemic cell lines. In addition, FAK protein expression and phosphorylation were determined using western blot analysis in order to investigate the mechanism by which doxycycline inhibited leukemic cell migration. The results revealed that doxycycline treatment significantly attenuated the migration of KG1a and K562 cells, which was demonstrated to be associated with inhibition of the expression and phosphorylation of FAK. In addition, doxycycline treatment inhibited matrix metalloproteinase (MMP)?2 and MMP?9 expression. Furthermore, incubation with blocking anti??1?integrin antibodies had an analogous inhibitory effect on leukemic cell migration to that of doxycycline. In conclusion, the results of the present study suggested that doxycycline attenuated leukemic cell migration through inhibiting the FAK signaling pathway. Therefore, doxycycline may have potential for use as a novel strategy for the treatment of leukemia.
PMID: 26004127 [PubMed - as supplied by publisher]
Ponatinib: a review of its use in adults with chronic myeloid leukaemia or Philadelphia chromosome-positive acute lymphoblastic leukaemia.
Drugs. 2014 May;74(7):793-806
Authors: Hoy SM
Oral ponatinib (Iclusig(®)) is a novel kinase inhibitor structurally designed with a carbon-carbon triple bond to accommodate the T315I mutation in the ABL kinase domain. It has demonstrated inhibitory activity against native BCR-ABL tyrosine kinase and a variety of BCR-ABL mutants, including T315I. Ponatinib is approved for the treatment of adults with T315I-positive chronic-, accelerated- or blast-phase chronic myeloid leukaemia (CML), or Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukaemia (ALL) [in the EU and the USA], as well as those with chronic-, accelerated- or blast-phase CML, or Ph+ ALL who are resistant or intolerant to prior tyrosine kinase inhibitor therapy (EU) or for whom no other tyrosine kinase inhibitor therapy is indicated (USA). In a noncomparative, multinational, phase II study, therapy with ponatinib was associated with a major cytogenetic response within the first 12 months in over half of adults with chronic-phase CML and major haematological responses within the first 6 months in at least 50% of adults with accelerated-phase CML and approximately 34% of adults with blast-phase CML or Ph+ ALL after a median follow-up duration of 15, 16 and 6 months, respectively. Such benefits were observed regardless of whether the patients were resistant to dasatinib or nilotinib, or had the T315I mutation. Serious adverse reactions have been reported with ponatinib, with vascular occlusion, heart failure and hepatotoxicity prompting the US FDA to issue boxed warnings. Ponatinib is a valuable treatment option for adults with T315I-positive chronic-, accelerated- or blast-phase CML, or Ph+ ALL, as well as those with chronic-, accelerated- or blast-phase CML, or Ph+ ALL who are resistant or intolerant to prior tyrosine kinase inhibitor therapy, but before starting treatment, clinicians need to consider whether the potential benefits of therapy will outweigh the risks.
PMID: 24807266 [PubMed - indexed for MEDLINE]
Treatment milestones in chronic myelogenous leukemia: stay the course or change therapy?
J Natl Compr Canc Netw. 2015 May;13(5 Suppl):697-9
Authors: Radich JP
The success of various generations of tyrosine kinase inhibitors in chronic myelogenous leukemia (CML) is well-known, with many patients experiencing long-term benefits from treatment. However, not every patient with CML can tolerate this therapy, shows response to initial treatment, or avoids disease progression or drug resistance. During his presentation at the NCCN 20th Annual Conference, Jerald Radich, MD, shared his thoughts and some supportive data on the critical role of monitoring response at 3 months, the often-neglected yet key issue of patient adherence to therapy, the recommended timing for mutational analysis, and the pressing need to prevent patients from going from chronic-phase disease into accelerated phase/blast crisis.
PMID: 25995434 [PubMed - in process]
Immune System Reaction against Environmental Pollutants.
Nihon Eiseigaku Zasshi. 2015;70(2):115-9
Authors: Tanabe T, Yamaguchi N, Okuda M, Ishimaru Y, Takahashi H
Environmental pollutants (such as diesel exhaust particles and silica) cause disorders ranging from bronchial asthma to malignant tumors. In recent years, it has been reported that some of the signaling pathways in which environmental contaminants act in vivo are associated with innate immunity. Innate immunity recognizes ligands and induces inflammation. Those ligands are pathogen-associated molecular patterns (PAMPs: e.g., lipopolysaccharide) and danger-associated molecular patterns (DAMPs: e.g., cholesterol crystallization or uric acid crystal). Activation of innate immunity stimulates the acquired immunity system. Therefore, innate immunity regulates the strength of the general immune system. Furthermore, crystal silica, which is an environmental pollutant, activates innate immunity as a ligand. Innate immunity involves the membrane-bound Toll-like receptors (TLR) and cytoplasm-localized nucleotide-binding oligomerization domain (NOD)-like receptors (NLR). We reported the innate immunity-system-related diseases such as Crohn’s disease, Blau syndrome, myelogenous leukemia, and sarcoidosis. An inflammasome complex containing NLR has attracted attention owing to its correlation with the onset of several diseases. It is reported that the inflammasome activation is related to the development of lifestyle-related diseases such as myocardial infarction and fatty liver. It is also reported that the mechanism by which crystal silica and asbestos cause inflammation involves the inflammasome activation. Analyzing the genes of innate immunity contributes to the clarification of the mechanism of disease onset caused by environmental pollutants.
PMID: 25994342 [PubMed - in process]
[Biological mechanisms of human-derived leukemia stem cells senescence regulated by Angelica sinensis polysaccharide].
Zhongguo Zhong Yao Za Zhi. 2015 Jan;40(1):112-7
Authors: Jia DY, Liu J, Li CP, Li J, Zhang MS, Zhang YY, Jing Peng-Wei, Xu CY, Wang YP
OBJECTIVE: To explore the biological mechanisms underlying Angelica sindsis polysaccharide (ASP) -induced aging of human-derived leukemia stem cells (LSCs) in vitro.
METHOD: Acute myelogenous leukemia stem cells were isolated by magnetic activated cell sorting (MACS). The ability of LSC proliferation treated by various concentration of ASP(20-80 mg · L(-1)) in vitro for 48 hours were tested using cell counting Kit-8 ( CCK8) , colony forming were evaluated by methylcellulose CFU assay. The ultra structure changes of AML CD34+ CD38- cells were analyzed by transmission electron microscopy. The aging cells were detected with senescence-?-galactosidase Kit staining. Expression of aging-related p53, p21, p16, Rb mRNA and P16, Rb, CDK4 and Cyclin E protein were detected by quantitative reverse transcription polymerase chain reaction( qRT-PCR) and Western blotting, respectively.
RESULT: The purity of the CD34 + CD38 – cells is (91.15 ± 2.41)% after sorted and showed good morphology. The proliferation of LSC was exhibited significantly concentration-dependent inhibited after exposure to various concentration of ASP. Treated by 40 mg · L(-1) ASP for 48 hours, the percentage of positive cells stained by SA-?-Gal was dramatically increased (P < 0.01) and the colony-formed ability has been weakened (P < 0.01). The observation of ultrastructure showed that cell heterochromatin condensation and fragmentation, mitochondrial swelling, lysosomes increased in number. Aging-related p53, p21, p16, Rb and P16, Rb were up-regulated, protein regulatory cell-cycle CDK4 and Cyclin E were down-regulated. ASP may induce the senescence of LSCs effectively in vitro, P16-Rb cell signaling pathway play a significant role in this process.
CONCLUSION: ASP can induce human leukemia stem cell senescence in vitro, the mechanism involved may be related to ASP regulation P16-Rb signaling pathways.
PMID: 25993799 [PubMed - in process]