Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic myeloid leukemia (CML) is caused by the constitutively active Bcr-Abl tyrosine kinase. This fusion protein is generated by the Philadelphia translocation t(9;22). CML is a progressive condition that invariably advances from a drug-sensitive to a drug-resistant, aggressive, acute leukemia. The mechanisms responsible for this progression are largely unknown; however, in many cases, progression is accompanied by an increase in Bcr-Abl expression. Osteopontin (OPN) expression has been shown to be involved in the progression and increased aggression and invasiveness of many solid tumors. Here, we demonstrate that OPN expression is induced in a model of leukemia, and we describe the identification of specific signaling pathways required for the induction of OPN expression by p210 Bcr-Abl. We have determined that high levels of Bcr-Abl activate a signaling cascade involving the sequential activation of Ras, phosphatidylinositol-3 kinase, atypical protein kinase C, Raf-1, and mitogen-activated protein kinase kinase, leading to the ultimate expression of OPN. Our results suggest that these molecules represent a single pathway and also that there is no redundancy in this pathway, as inhibition of any individual component results in a block in the induction of OPN. The data presented here define for the first time the ability of Bcr-Abl to stimulate the expression of OPN and also identify the signaling pathway involved. This may not only prove important in understanding the mechanisms of progression of CML but also highlights a pathway that may prove significant in many other cases of oncogenesis, where OPN expression is implicated.
 ...
PMID:Bcr-Abl regulates osteopontin transcription via Ras, PI-3K, aPKC, Raf-1, and MEK. 1585 38

Chronic myeloid leukemia (CML) is a hematopoietic stem cell disorder characterized by the balanced reciprocal translocation t (9:22). The resulting fusion gene, the BCR-ABL, is responsible for oncogenesis. Imatinib mesylate is a novel molecule, which inhibits the protein product of this fusion gene and hence has been used in the treatment of CML. The present study evaluates 174 patients with CML treated with imatinib mesylate. Of these 174 patients, 97 were in chronic phase, 47 in accelerated phase and 30 patients had blast crisis. Patients in chronic phase received imatinib mesylate in the dose of 400-mg daily, while those in accelerated phase and blast crisis received 600 to 800 mg daily. Of the 97 patients with chronic phase, 49 patients (50.5%) achieved a major (major + complete) cytogenetic response. Of the 47 patients in accelerated phase, 10 patients (21.3%) achieved a major cytogenetic response and in 30 patients with blast crisis, 7 (23.3%) achieved a major cytogenetic response. Dermatitis, mucositis, neutropenia and thrombocytopenia were some of the major toxicities. Of interest, 121 of the 174 patients (69.5%) developed generalized hypopigmentation. We conclude that imatinib mesylate is a safe and effective first-line therapy for chronic myeloid leukemia.
 ...
PMID:Imatinib mesylate in chronic myeloid leukemia: a prospective, single arm, non-randomized study. 1598 13

MYC is frequently overexpressed in human cancers, but the downstream events contributing to tumorigenesis remain incompletely understood. MYC encodes an oncogenic transcription factor, of which target genes presumably contribute to cellular transformation. Although Myc regulates about 15% of genes and combinations of target genes are likely required for tumorigenesis, we studied in depth the expression of the Myc target gene, JPO1/CDCA7, in human cancers and its ability to provoke tumorigenesis in transgenic mice. JPO1/CDCA7 is frequently overexpressed in human cancers, and in particular, its expression is highly elevated in chronic myelogenous leukemia blast crisis as compared with the chronic phase. In murine lymphoid tissues, ectopic human JPO1/CDCA7 expression resulted in a 2-fold increased risk of lymphoid malignancies at 1 year. The transgene, which was driven by the H2-K promoter, exhibited leaky expression in nonlymphoid tissues such as kidney. We observed a significant increased incidence of transgenic animal solid tumors, which were not seen in littermate controls. These observations suggest that JPO1/CDCA7 may contribute to Myc-mediated tumorigenesis.
 ...
PMID:The Myc target gene JPO1/CDCA7 is frequently overexpressed in human tumors and has limited transforming activity in vivo. 1599 34

Oncogenesis results from a progressive accumulation of genetic aberrations consequent to a complex interplay between carcinogenic factors and innate infidelity of DNA surveillance mechanisms. Although the development of genetic aberrations is random, those conferring survival advantages are selected for in a Darwinian manner, thus allowing continuous adaptation to selection pressures. Chromosomal aberrations are a prominent manifestation of genetic damage, which can be closely linked with tumor behavior and outcome as exemplified by curative treatment of chronic myelogenous leukemia resulting from targeting the BCR-ABL translocation. In the case of head and neck squamous cell carcinomas (HNSCC), chromosomal changes are detectable at all stages of tumor development, providing excellent opportunities for genomic prognostication and therapy. Several studies have shown that the overall genomic profile of HNSCC is highly consistent, but individual tumors vary significantly in their complement of genetic alterations, thereby confounding clinical correlation. The application of modern genetic and bioinformatic analytic approaches has facilitated the identification of critical genomic changes in HNSCC, many of which have been linked to clinical outcome. These genetic aberrations represent excellent targets for novel therapeutics, but require validation. The initiation of phase III trials evaluating the therapeutic utility of genetic aberrations suggests a promising future for genome-based treatment of HNSCC.
 ...
PMID:Chromosomal aberrations in squamous cell carcinomas of the upper aerodigestive tract: biologic insights and clinical opportunities. 1609 Nov 11

Aberrant genome-wide hypomethylation is thought to be related to tumorigenesis by promoting genomic instability. Since DNA methylation is considered an important mechanism for the silencing of retroelements, hypomethylation in human tumors may lead to their reactivation. However, the role of DNA hypomethylation in chronic myeloid leukemia (CML) remains to be elucidated. In this study, the methylation status of the LINE-1 (L1) retrotransposon promoter was analysed in CML samples from the chronic-phase (CP, n=140) and the blast crisis (BC, n=47). L1 hypomethylation was significantly more frequent in BC (74.5%) than in CP (38%) (P<0.0001). Furthermore, L1 hypomethylation led to activation of both ORF1 sense transcription (P<0.0001) and c-MET gene antisense transcription (P<0.0001), and was significantly associated with high levels of BCR-ABL (P=0.02) and DNMT3b4 (P=0.001) transcripts. Interestingly, in CP-CML, extensive L1 hypomethylation was associated with poorer prognosis in terms of cytogenetic response to interferon (P=0.004) or imatinib (P=0.034) and progression-free survival (P=0.005). The above results strongly suggest that activation of both sense and antisense transcriptions by aberrant promoter hypomethylation of the L1 elements plays a role in the progression and clinical behavior of the CML.
 ...
PMID:Promoter hypomethylation of the LINE-1 retrotransposable elements activates sense/antisense transcription and marks the progression of chronic myeloid leukemia. 2338 83

The Bcr-Abl fusion kinase drives oncogenesis in chronic myeloid leukemia (CML). CML patients are currently treated with the Abl tyrosine kinase inhibitor imatinib, which is effective in early stages of the disease. However, resistance to imatinib arises in later disease stages primarily because of a Bcr-Abl mutation. To gain deeper insight into Bcr-Abl signaling pathways, we generated phosphotyrosine profiles for 6 cell lines that represent 3 Bcr-Abl fusion types by using immunoaffinity purification of tyrosine phosphopeptides followed by tandem mass spectrometry. We identified 188 nonredundant tyrosine-phosphorylated sites, 77 of which are novel. By comparing the profiles, we found a number of phosphotyrosine sites common to the 6 cell lines regardless of cellular background and fusion type, several of which are decreased by imatinib treatment. Comparison of this Bcr-Abl signature with the profile of cells expressing an alternative imatinib-sensitive fusion kinase, FIP1L1-PDGFRalpha, revealed that these kinases signal through different pathways. This phosphoproteomic study of the Bcr-Abl fusion kinase highlights novel disease markers and potential drug-responsive biomarkers and adds novel insight into the oncogenic signals driven by the Bcr-Abl kinase.
 ...
PMID:A common phosphotyrosine signature for the Bcr-Abl kinase. 1649 76

Imatinib mesylate (IM), a small molecule that is a selective inhibitor of the ABL, platelet derived growth factor receptor (PDGFR-R) and stem cell ligand receptor (c-kit) tyrosine kinases (TK). IM was also found to inhibit the TK activity of BCR/ABL fusion protein produced in chronic myelogenous leukemia, with marked clinical activity against the disease. Since both PDGF-R and c-kit both having a putative role in tumorigenesis, we investigated the efficacy and safety of the use of IM in patients with endocrine tumors unresponsive to conventional therapies that expressed c-kit and/or PDGF-R (within the framework of a comprehensive phase II multi-center study of IM in patients with solid tumors). IM was initiated at a dose of 400 mg/day, with possible dose escalation within 1 week to 600 mg/day and an option to raise the dose to 800 mg/day in the event of progression and in the absence of safety concerns for a period of up to 12 months. Between September 2002 and July 2003, 15 adult patients with disseminated endocrine tumors were recruited as follows: medullary thyroid carcinoma (MTC, n = 6); adrenocortical carcinoma (ACC, n = 4); malignant pheochromocytoma (pheo, n = 2); carcinoid (non-secreting, n = 2), neuroendocrine tumor (NET, n = 1). No objective responses were observed. MTC--disease progression in 4 patients, and treatment discontinuation in 2 patients due to adverse events; ACC--disease progression in 3 patients, and treatment discontinuation in 1 patient due to severe psychiatric adverse event; Pheo--disease progression in 2 patients; Carcinoid--stable disease in 1 patient (6.5 months), and disease progression in 1 patient; NET--disease progression in 1 patient. IM does not appear to be useful for treatment of malignant endocrine tumors, also causing significant toxicity in this patient population.
 ...
PMID:The role of imatinib mesylate (Glivec) for treatment of patients with malignant endocrine tumors positive for c-kit or PDGF-R. 1672 80

Bio-cell chip is a chip that has hundreds of types of cells arrayed and immobilized on a small slide. To elucidate the role of deletion of the p16 gene in hematologic malignancies, the bio-cell chip technique was applied to fluorescent in situ hybridization (FISH) study. We made a bio-cell chip with bone marrow specimen from 109 patients with acute lymphoblastic leukemia (ALL), 102 patients with acute myelogenous leukemia (AML), 47 patients with chronic myelogenous leukemia (CML), and 25 patients with multiple myeloma (MM). A glass slide with 96 separated areas was fabricated, onto which was added methanol/acetic acid fixed cell suspensions for high-throughput FISH for p16. With the successful application of bio-cell chip technique, we found that the deletion of p16 contributed to the oncogenesis in acute leukemia, but not in chronic leukemia. In conclusion, the bio-cell chip, a cell version of ultrahigh-throughput technology, was successfully applied to the FISH study, which can be utilized efficiently in the molecular cytogenetic investigation of hematologic malignancies.
 ...
PMID:Application of high throughput cell array technology to FISH: investigation of the role of deletion of p16 gene in leukemias. 1694 74

Development of array methods contributes to elucidation of many genes expressed during oncogenesis. Our array-based analyses of gene expression in patients with chronic myeloid leukemia (CML) revealed several genes (MMP8, MMP9, PCNA, JNK2, MAPK p38) with significant increased expression. We suppose that the genes may be implicated in the disease development and a siRNA-suppression can elucidate their functions in leukemogenesis. One of the crucial requirements for this purpose is a high efficiency of siRNA delivery into CML primary cells. Using fluorescein-labeled siRNAs we systematically tested a variety of physical and chemical non-vector based transfection methods in order to evaluate which of them gave the most suitable transfer. Chemically synthesized siRNAs against mentioned genes were transfected into the cells and level of knockdown was determined by real time RT-PCR. Chemical transfection reagents (Oligofectamine, Metafectene, siPORT Amine) commonly used to transfect siRNAs in CML cell lines showed very low siRNA delivery in CML primary cells-mRNA levels decreased at the most to 76%. Electroporation achieved better results (suppression to 63%) but it was associated with high degree of cell death (more than 60%). In the study we obtained the best transfection efficiency using nucleofector technology. Gene expressions ranged 22-37% that remained from original levels. According to our results, nucleofection appears to be the only suitable non-viral method for siRNA delivery into the hard-to-transfect CML primary cells.
 ...
PMID:Targeting of gene expression by siRNA in CML primary cells. 1709 12

The role of the abl oncogene family in cellular transformation has been well established, but knowledge of its role in apoptosis is limited. Recent studies demonstrate that it may act as a suppressor of apoptosis in certain circumstances. The growth factor independence conferred on IL-3 dependent myeloid progenitor cell lines following v-Abl transformation is due to the suppressive effects of this oncogene on apoptosis. Similarly, inhibition of the deregulated activity of the p210(bcr-abl) protein in both myeloid progenitor lines and CML granulocytes has proven effective in reversing resistance to apoptosis in such cells. The Bcr-Abl fusion protein might therefore promote myeloid expansion by suppression of apoptotic cell death rather than through promoting proliferation. While oncogenic forms of Abl appear to be anti-apoptotic, the function of c-Abl remains elusive. Through the elucidation of the roles in cell growth and survival of the Abl family members we may gain valuable insights into the regulation of apoptosis and the mechanisms of oncogenesis.
 ...
PMID:The abl oncogene family and apoptosis. 1718 20


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>