Posted by rob on July 28, 2010 under Uncategorized | 
Hematopoietic progenitor cell collection in patients with chronic myelogenous leukemia in complete cytogenetic remission after imatinib mesylate therapy.
Leuk Lymphoma. 2010 Jul 27;
Authors: Bashir Q, De Lima MJ, McMannis JD, Garcia-Manero G, Shpall E, Kantarjian H, Cortes JE, O’Brien SM, Jones D, Qazilbash M, Wei W, Giralt SA, Champlin RE, Hosing C
The introduction of BCR-ABL tyrosine kinase inhibitors such as imatinib has changed the treatment of chronic myelogenous leukemia (CML). More than 75% of patients achieve complete cytogenetic remission (CCR) after treatment with imatinib, which provides an opportunity to collect minimally involved hematopoietic progenitor stem cell (HPC) products. In order to assess the feasibility of HPC collection in patients with CML, we prospectively enrolled 24 patients who achieved CCR on therapy with imatinib. Two patients could not undergo HPC collection because of coagulopathy. A CD34+ cell yield of >/=2.0 x 10(6)/kg body weight was obtained in 16/22 (73%) patients. Patients who stopped imatinib for at least 3 weeks prior to HPC collection had significantly higher CD34+ cell yields (median: 6.52 x 10(6)/kg body weight) when compared with patients who continued imatinib through the collection (median: 3.74 x 10(6)/kg body weight). Mobilization with granulocyte colony-stimulating factor (G-CSF) did not increase the levels of BCR-ABL transcript. With a mean follow-up of 46 months, all patients but one were in CCR. In conclusion, a significant number of CD34+ cells can be safely collected in patients with CML who are on imatinib therapy, but CD34+ cell yields improve when imatinib is temporarily withheld.
PMID: 20658954 [PubMed - as supplied by publisher]
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Posted by rob on under Uncategorized |
Wnt/Ca2+/NFAT signaling maintains survival of Ph+ leukemia cells upon inhibition of Bcr-Abl.
Cancer Cell. 2010 Jul 13;18(1):74-87
Authors: Gregory MA, Phang TL, Neviani P, Alvarez-Calderon F, Eide CA, O’Hare T, Zaberezhnyy V, Williams RT, Druker BJ, Perrotti D, Degregori J
Although Bcr-Abl kinase inhibitors have proven effective in the treatment of chronic myeloid leukemia (CML), they generally fail to eradicate Bcr-Abl(+) leukemia cells. To identify genes whose inhibition sensitizes Bcr-Abl(+) leukemias to killing by Bcr-Abl inhibitors, we performed an RNAi-based synthetic lethal screen with imatinib mesylate in CML cells. This screen identified numerous components of a Wnt/Ca(2+)/NFAT signaling pathway. Antagonism of this pathway led to impaired NFAT activity, decreased cytokine production, and enhanced sensitivity to Bcr-Abl inhibition. Furthermore, NFAT inhibition with cyclosporin A facilitated leukemia cell elimination by the Bcr-Abl inhibitor dasatinib and markedly improved survival in a mouse model of Bcr-Abl(+) acute lymphoblastic leukemia (ALL). Targeting this pathway in combination with Bcr-Abl inhibition could improve treatment of Bcr-Abl(+) leukemias.
PMID: 20609354 [PubMed - indexed for MEDLINE]
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Posted by rob on under Uncategorized |
Chronic myeloid leukemia: mechanisms of blastic transformation.
J Clin Invest. 2010 Jul 1;120(7):2254-64
Authors: Perrotti D, Jamieson C, Goldman J, Skorski T
The BCR-ABL1 oncoprotein transforms pluripotent HSCs and initiates chronic myeloid leukemia (CML). Patients with early phase (also known as chronic phase [CP]) disease usually respond to treatment with ABL tyrosine kinase inhibitors (TKIs), although some patients who respond initially later become resistant. In most patients, TKIs reduce the leukemia cell load substantially, but the cells from which the leukemia cells are derived during CP (so-called leukemia stem cells [LSCs]) are intrinsically insensitive to TKIs and survive long term. LSCs or their progeny can acquire additional genetic and/or epigenetic changes that cause the leukemia to transform from CP to a more advanced phase, which has been subclassified as either accelerated phase or blastic phase disease. The latter responds poorly to treatment and is usually fatal. Here, we discuss what is known about the molecular mechanisms leading to blastic transformation of CML and propose some novel therapeutic approaches.
PMID: 20592475 [PubMed - indexed for MEDLINE]
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Posted by rob on under Uncategorized |
We report here a patient first diagnosed with Fanconi anemia at age 10. Bone marrow transplantation was performed at age 23 and repeated after an episode of rejection at age 25. Hematologic findings returned to normal, but chronic graft-versus-host disease persisted. Esophageal cancer developed at age 35. Invasion of the bronchus and aorta by the tumor was suspected on computed tomography. Chemoradiotherapy was administered to down-stage the tumor, using low-dose cisplatin and 5-fluorouracil. After two courses of chemotherapy with cisplatin (total dose, 100 mg) and 5-fluorouracil (5000 mg) plus radiotherapy (30 Gy), Grade 3 diarrhea and bone marrow suppression developed, and treatment was discontinued. After resolution of toxicity, a good response to the neoadjuvant therapy was seen on com…
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